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UPCOMING EAPS MEETINGS EAPS PRESENTATIONS EAPS STAFF MEETINGS Thursday, Nov. 20th CLIMATE CHANGE IN THE 20TH CENTURY: LESSONS 9:00-10:00 a.m. FROM THE DARK SIDE OF THE MOON HAMP 2201 Dr. Richard A. Keen Emeritus Instructor of Atmospheric Sciences, University of ~ ~ ~ ~ ~ ~ Colorado EAPS RECEPTIONS AT CONFERENCES Monday, Oct. 20, 2014 at 3:30 p.m. Lilly 2-425 GSA (Vancouver) Monday, Oct. 20, 2014 ******************************************************************** 7:00 - 9:00 p.m. EAPS COLLOQUIA Vancouver Hyatt Regency-Cypress Room

SEG (DENVER) TOWARDS A PARADIGM SHIFT IN THE MODELING OF Monday, Oct. 27, 2014 SOIL ORGANIC CARBON DECOMPOSITION FOR 6:00 - 8:00 p.m. EARTH SYSTEM MODELS Denver Hilton Garden Inn-Element Ballroom Yujie He PhD Candidate AGU (SAN FRANCISCO) Tuesday, Oct. 21, 2014 at 4:00 p.m. HAMP 2201 Wednesday, Dec. 17, 2014 7:00 - 9:00 p.m. Thirsty Bear-Billar Room ANTHROPOGENIC SIGNALS IN INSAR Rowena Lohman Cornell Universtiy AMS (PHOENIX) Tuesday, Jan. 6, 2015 Thursday, Oct. 23, 2014 at 3:30 p.m. HAMP 1252 6:30 - 8:30 p.m. TBA GIANT IMPACTS ON THE ASTEROID 4 VESTA ~ ~ ~ ~ ~ ~ Timothy Bowling FALL FACULTY MEETING SCHEDULE PhD Candidate Tues., Oct. 28, 2014 at 4:00 p.m. Tuesday, Nov. 18th HAMP 2201 3:00-4:30 p.m. HAMP 3201 (Please see attached fall 2014 EAPS Colloquia)

SPRING FACULTY MEETING SCHEDULE EAPS PUBLICATIONS Tuesday, Jan. 27th, Feb. 10th (Dean’s Visit to Dept.), Mar. 24th, and Apr. 14th, 2015 Agee, Ernest M., 2014: A revised definition and 3:00-4:30 p.m. changes in tornado taxonomy. Wea. Forecasting, 29, 1256- HAMP 3201 1259, DOI: 10.1175/WAF-D-14-00058.1

~ ~ ~ ~ ~ ~ EXTERNAL REVIEW Nov. 3rd & 4th

Detailed schedule was placed in faculty mailboxes.

CCO WORKSHOPS UNDERGRADUATE AND GRADUATE STUDENT INFORMATION LinkedIn - Online Networking Thur. Oct. 23 | 5:30-6:30pm | EE117 Job and Salary Negotiation GREEN WEEK ACTIVITIES Wed. Oct. 29 | 5:30-6:30pm | EE117 Acing the Interview A Discovery Lecture offered in conjunction with Purdue Tues. Nov. 4 | 5:30-6:30pm | EE117 University's Green Week 2014 will feature a talk by award- winning National Geographic magazine photographer Joel ******************************************************************** Sartore at 7 p.m. in Purdue Memorial Monday (Oct. 20) GRADUATE STUDENTS-CHILD WELLNESS DAY Union's North Ballroom. The free lecture, titled "Photo Ark: Communicating Science through the Lens," will explore Sartore's 20-year effort launched in 2008 to document Tippecanoe County Health Department endangered species and landscapes. More than 3,700 October 24, 2014 species have been photographed to date for Photo Ark. 10:00 a.m.-4:00 p.m.

To register online, please click here: ******************************************************************* https://www2.itap.purdue.edu/bs/worklife/ See attached flyer for more information. BILINGUAL CAREER FAIR AND RECEPTION NEW DEPARTMENTAL REGULATION

The CCO, in conjunction with the America China Society As you may be aware, the Graduate School has a new of Indiana, and Purdue Chinese Students and Scholars policy change with regards to plagiarism that began on Association are hosting a Bilingual Career Fair and September 1, 2014. All students (and their Major rd th Networking Reception on November 3 and 4 , 2014. Professors) must sign a statement on Graduate School Students with language and technical skills that are looking Form 32 certifying that their thesis/dissertation is free of for both internships and full time opportunities should plagiarism and all materials appearing have been properly consider attending. Companies will be looking for students quoted and attributed. Towards that end, your interested in both home country and international positions. thesis/dissertation must now go through an iThenticate All majors are welcome! Please see attached flyer. review. Therefore, the department has established a new departmental regulation with regards to this new policy. The ******************************************************************** new regulation states: NETWORKING RECEPTION “A PDF of your final thesis/dissertation must be turned into This event is a unique opportunity for students and the Graduate Committee or Major Professor a minimum of employers to expand their professional networks and two weeks prior to thesis/dissertation deposit to conduct an engage in meaningful discourse about international student iThenticate check. Failure to meet this deadline may affect success in the workplace. submission of your thesis/dissertation which may, in turn, delay your graduation date.” Date: November 3, 2014 Time: 5:00-8:00 p.m. ******************************************************************** Location: Dauch Alumni Center (403 W. Wood Street) 2015 AMS TRAVEL GRANT FOR EAPS GRADUATE STUDENTS Keynote speech “Branchind you multiculturalism—present by Partrice Kimerson . A Travel Grant has been established by a donor to provide $500 in travel funds for an EAPS graduate student to attend and present at any American Meteorological Society (AMS) Students must register via my CCO. There is a limited meeting. This call is for travel to AMS meetings that will be capacity. Registration will close on October 28. held in 2015.For a list of AMS meetings, see http://goo.gl/QeRYH2.The $500 travel award is limited to ******************************************************************** EAPS graduate students who plan to make an oral or poster presentation at any AMS meeting. Students may apply in BILINGUAL CAREER FAIR advance of their paper/poster being accepted. Should a Date: November 4, 2014 student be awarded the travel grant and their paper/poster Time: 10:00am-3:00pm is not accepted, the travel monies will be forfeited and will Location: France A. Crdova Recreational Sports Center be made available to another student (at the discretion of (Feature Gym) the award selection committee). Students need to provide electronic files via email attachment to Kathy Kincade View the list of attending employers . ([email protected]) including the cover sheet (2nd page of this document), an abstract and title of the proposed presentation, and an advisor’s letter of nomination by the required due date to be considered. The awardee will be continues on Sunday, January 4 and is open to all Annual selected by a faculty committee appointed by the Head. Meeting attendees, including attendees of the Early Career Awardees must submit a travel request a minimum of two Professionals Conference. The hours of operation for weeks before departure using the standard departmental Saturday and Sunday are as follows: travel procedures - see the Business Office for details. The funds will be provided as reimbursement for normal travel Saturday 5:30 p.m. – 7:30 p.m. expenses. Sunday 5:00 p.m. – 7:00 p.m.

The complete application must be submitted electronically to You’re invited to take advantage of this opportunity to Kathy Kincade ([email protected]) by 5:00 PM on promote your organization and to network with qualified Thursday, October 30, 2014. applicants. If your organization is a Sustaining, Regular, or Small Business AMS Corporation and Institutional ******************************************************************** Member (CIM), your Career Fair registration is free of charge! Please contact Beth Farley at [email protected] for a coupon code with which to P. F. LOW AGU TRAVEL AWARD COMPETITION FOR submit your order. The registration fee for all other EAPS PHD STUDENTS organizations, including Publication CIMs, is $120. All recruiters are provided with one 6’ table, two chairs, and The P. F. Low AGU Travel Award is sponsored by access to Career Fair attendee resumes. To reserve space Professor Cushman to provide travel funds for one EAPS at the 2015 event, please visit our Web site at PhD student to make a presentation at the Fall (San http://careercenter.ametsoc.org/home/index.cfm?site_id=42 Francisco, CA) American Geophysical Union (AGU) 1 and register as an EMPLOYER. Space is very limited so meeting. The award is named in honor of the late Philip F. requests will be processed on a first-come, first-served Low, a member of the National Academy of Sciences and a basis. Specific information about the Career Fair will be pioneer in the rigorous use of thermodynamics for the study emailed to you after we receive your reservation. of clay-water interactions. Visit the AMS Web site for additional information on the Career Fair and other Annual Meeting activities. A travel award of (up to) $1000 will be awarded to support one EAPS student to present at the AGU fall meeting. ******************************************************************** Funds will be provided as reimbursement for normal travel expenses. Awards will be made based on merit of the research project, as well as on financial need. Students GLACIATION IN SWEDEN need to electronically provide the cover sheet (see below), STUDY ABROAD COURSE an abstract of the proposed presentation, and an advisor’s MAY 4-JUNE 5, 2015 letter of nomination by the required due date to be considered.

The complete application must be submitted electronically 3 Credits: Estimated maximum cost $3,000, including to Kathy Kincade ([email protected]) by 5:00PM on tuition, all travel, food, and lodging Thursday, October 30, 2014. (University and college study abroad scholarships may reduce this cost significantly)

OTHER NEWS Glaciation in Sweden focuses on reconstructing past glacial history based on an understanding of glacial AMERICAN METEOROLOGICAL SOCIETY CAREER processes combined with evidence from landforms and FAIR TH sediments. It involves course and fieldwork jointly with 95 ANNUAL MEETING students taking an equivalent course at Stockholm JANUARY 3-4, 2015 University. This course is intended for juniors and seniors majoring in geology, as well as graduate students with Participating in the AMS Career Fair is the perfect way for interests in geomorphology and Quaternary geology. The your organization to attract the attention of the thousands of study abroad course will run from May 4th to June 5th (May professionals, recent graduates, and current students, 4th-May 21st in West Lafayette, May 21st to June 5th in expected to attend the AMS Annual Meeting in Phoenix, Sweden. Arizona. The AMS Career Fair provides an environment to If you are interested, please send an email ASAP to showcase full-time and part-time job opportunities, the instructor at [email protected] letting him know internships, graduate programs, and professional you are interested. Expressing interest is not a development opportunities. Whether you have jobs to fill or commitment to take part in the program. This program will career advice to share, our attendees want to talk to you! only be offered if there are enough students interested. If at The Career Fair opens on Saturday, January 3 with a least six people have expressed interest by October 25th , reception for the more than 700 graduate students and there will be an information session to discuss the details. junior and senior undergraduate students expected to attend Please see attached flyer for more details. the 14th Annual AMS Student Conference. The Career Fair

BIRTHDAYS

Kathy Kincade Oct. 24th

IMPORTANT NOTICE ABOUT THIS NEWSLETTER This newsletter is used as the primary information source for current and upcoming events, announcements, awards, grant opportunities, and other happenings in our department and around campus. Active links to additional information will be provided as needed. Individual email announcements will no longer be sent unless the content is time-sensitive. We will continue to include our publications, presentations and other recent news items as well. Those using paper copies of the newsletter should go to our newsletter archive on the EAPS website at www.purdue.edu/eas/ and Click on News to access active links as needed. Material for inclusion in the newsletter should be submitted to Fallon Seldomridge ([email protected]) by 5:00pm on Thursday of each week for inclusion in the Monday issue. If it is in the newsletter, we assume you know about it and no other reminders are needed. For answers to common technology questions and the latest updates from the EAPS Technology Support staff, please visit http://www.purdue.edu/eas/info_tech/index.php. Also, as an additional resource for information about departmental events, seminars, etc., see our departmental calendar at http://calendar.science.purdue.edu/eas/seminars.

-,0 --... TE ,CTO EC ,REL TIO S t-ll lPS Climate Change in the 20th Century:

Lessons from the Dark Side of the Moon

Dr. Richard A. Keen

Emeritus Instructor of Atmospheric Sciences, University of Colorado

The subject of climate change is huge and complex. This presentation will focus on two specific climate related topics, and extrapolate the results to the global climate change.

Volcanoes - The first is an examination of the impact of large volcanic eruptions on the transparency of the stratosphere, using observations of the brightness of lunar eclipses to determine the optical depth of volcanic aerosols. Between 1979 and 1995, aerosols from el Chichon (1982) and Pinatubo (1991) reduced the net heating (i.e., "radiative forcing") of the earth's surface. Since 1995, the absence of volcanic aerosols effectively increased the radiative forcing by 0.7 W/m2, an amount slightly greater than the increased forcing due to all greenhouse gases (GHG). Using simple radiative calculations, the effects of volcanoes and GHG are sufficient to explain most of the 0.3C global temperature increase measured by the orbiting MSU sensors over the same time period. These observations imply a "climate sensitivity" to a doubling of CO2 of 0.7C, and that CO2 induced global warming since 1900 is about 0.3C.

Alaska - The other study is of the climate of central Alaska since the start of thermometer records during the 1899 Gold Rush. Alaska is noted for its volatile climate, with 30-year climatological means varying by 1C to 2C over the past century. Most (66 percent) of this variance is explained by the Pacific Decadal Oscillation (PDO) and/or North Pacific Oscillation (NP), which are internal oscillations of the earth- atmosphere system operating on time scales of ~60 years. External radiative forcings (solar, GHG, volcanoes) explain about 1 percent of the variance. The deconstructed contribution of CO2 is 0.2C, close to the result of the volcano study. Alaska is a relatively data rich region, but the sparse network of climate stations elsewhere around the planet may fail to catch similar large regional changes. Prior to 1979, the global coverage of climate stations is only about 30 percent, not sufficient for measuring global temperatures to an accuracy of 0.3C.

Climate Change - Tying things together, a scenario that emerges is one of large ~1C warm and cool regional changes due to ~60 year ocean-atmosphere oscillations superimposed on ~0.2C global changes caused by radiative forcings over the same time scales. Although warm and cool regional changes may average out to contribute very little variation to the global mean, the irregular and sparse sampling of climate stations could lead to calculated global averages that are several tenths of a degree in error.

1256 WEATHER AND FORECASTING VOLUME 29

A Revised Tornado Definition and Changes in Tornado Taxonomy

ERNEST M. AGEE Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, Indiana

(Manuscript received 4 June 2014, in final form 30 July 2014)

ABSTRACT

The tornado taxonomy presented by Agee and Jones is revised to account for the new definition of a tor- nado provided by the American Meteorological Society (AMS) in October 2013, resulting in the elimination of shear-driven vortices from the taxonomy, such as gustnadoes and vortices in the eyewall of hurricanes. Other relevant research findings since the initial issuance of the taxonomy are also considered and in- corporated, where appropriate, to help improve the classification system. Multiple misoscale shear-driven vortices in a single tornado event, when resulting from an inertial instability, are also viewed to not meet the definition of a tornado.

1. Introduction and considerations from a cumuliform cloud, and often visible as a and/or circulating debris/dust at the ground.’’ In The first proposed tornado taxonomy was presented view of the latest definition, a few changes are warranted by Agee and Jones (2009, hereafter AJ) consisting of in the AJ taxonomy. Considering the roles played by three types and 15 species, ranging from the type I buoyancy and shear on a variety of spatial and temporal (potentially strong and violent) tornadoes produced by scales (from miso to meso to synoptic), coupled with the the classic , to the more benign type III con- requirement in the latest definition that a tornado must vective and shear-driven vortices such as and be pendant from a cumuliform cloud, it is necessary to gustnadoes. This original taxonomy was presented to reexamine the AJ taxonomy. (i) help organize and sort out the variety of tornado oc- currences, with different roles played by varying strengths a. Changes in the taxonomy and patterns of buoyancy/CAPE and shear/helicity, and There are some minor and/or significant changes in (ii) to accommodate the change in nomenclature made by each of the three types of tornado classification due to the American Meteorological Society (AMS) in the Glos- a combination of the following: the new tornado sary of Meteorology from its original 1959 definition to the definition, recent research investigations, comments revised definition in 2000 (Huschke 1959; Glickman 2000). by Markowski and Dotzek (2010, hereafter MD),and These comments are being provided now because the AMS e-mails received by the author. Purely shear-driven has revised the definition againinOctober2013(seehttp:// vortices (although indirectly associated with cumuli- glossary.ametsoc.org/wiki/Tornado), which has direct im- form convective clouds) must be dropped from the pact on the Agee–Jones taxonomy. The succession of original AJ taxonomy. This includes the gustnadoes three tornado definitions are (i) 1959—‘‘a violently rotating (type IIId), as well as hurricane eyewall shear vortices column of air, pendant from a cumulonimbus cloud’’; (ii) (type IIIe). 2000—‘‘a violently rotating column of air, in contact with Contrary to the wishes of many in the severe the ground, either pendant from a cumuliform cloud or community, the 2000 Glossary defined gustnadoes as underneath a cumuliform cloud’’; and (iii) 2013—‘‘a ro- tornadoes (which AJ had no choice in the matter in tating column of air, in contact with the surface, pendant presenting their taxonomy because of their adherence to the Glossary definition). Considering now in the new definition that the vortex in contact with the ground Corresponding author address: Ernest M. Agee, Dept. of Earth, Atmospheric, and Planetary Sciences, Purdue University, 550 ‘‘must be pendant from a cumuliform cloud’’ implicates Stadium Mall Dr., West Lafayette, IN 47907-2051. the presence and role of convective buoyancy in vortex E-mail: [email protected] formation (thus eliminating shear vortices as noted

DOI: 10.1175/WAF-D-14-00058.1

 2014 American Meteorological Society OCTOBER 2014 A G E E 1257 Tornado Classification System

Type I Type II Type Ill QLCS Localized Convective (with ) (Cold Pool , Shear, and Shear Vortices Mesocyclone) I lla- LEWPs I I I Illa- Landspouts la- Classic Supercells (SR , SL) I llb- Bows I I I II lb-• llc-BEVs I lb- Low-Top Mini­ Ille- Cold Air Supercells I Funnels lld- lJs le- Tropical / Hurricane Related •Type I and Type II "waterspouts" lie- Other Mini-Supercells are also possible Id- Anticyclonic I Secondary Vortices llf- Tropical Storm/ Hurricane Spiral Bands

FIG. 1. Revised tornado taxonomy (after Agee and Jones 2009). above) but continuing to allow tornadoes in the type III b. Multiple vortices and tornado definition class, namely landspouts, waterspouts (with landfall), and even a few cold-air funnels when in contact with the The occurrence of multiple vortex tornadoes has ground. Simply stated, the combined roles of shear and long been recognized, as seen in the early observa- buoyancy, as well as the associated dynamical and ki- tions of the 3 April 1974 tornado outbreak (Agee nematic processes of tilting–convergence–stretching, et al. 1975). A single tornadic is also must act together in the presence of a cumuliform cloud capable of supporting two or more minitornado cy- updraft embedded in a environment to form clones (Agee et al. 1976) capable of producing in- a vortex that is a candidate for becoming a tornado. It is dividual tornadoes, resulting in a parallel mode further noted that the anticyclonic secondary vortex tornado family [also see Fujita (1974)]. Over the de- (type IIIf) has been relocated in the revised taxonomy to cades there have been many observations and in- type I (and labeled as Id). This relocation is consistent vestigations of vortices associated with tornado with the recommendation made by MD, as well as by events, but nothing comparable to those reported on Agee and Jones (2010, hereafter AJ2). Changes in type by Wurman and Kosiba (2013, hereafter WK).The II species are minor, but the nomenclature of rear inflow complexity of their Doppler observations of a multi- jeats (RIJs) has been changed to inflow jets (IJs) since tude of vortices on several different scales has resulted inflow features that occur in quasi-linear convective in their proposal for a new tornado definition and, thus, system (QLCS) events can be either from the front or requires some consideration in this contribution. The the rear. Accordingly, an updated taxonomy is pre- author views that tornadoes (particularly strong and vio- sented in Fig. 1, as well as a newly revised table of tax- lent tornadoes) can (and should) display multiple vortex onomy species criteria (Table 1). The comment and features with a variety of sizes. Large two-cell vortices reply articles by MD and AJ2, as well as the reviews (such as wedge ) can be viewed as a coalescence received for this publication, require additional com- or bundling of vortex tubes of different sizes. Such are ments regarding tornadic supercell . Ad- sometimes visible to even the naked and at an im- mittedly, there are some mixed views concerning the pressive level, as is evident in the movies of the Tuscaloosa, placement (or not) of supercells in lines (i.e., in the type Alabama, tornado of 27 April 2011. However, the un- II classification). Although QLCS may contain storm precedented findings by WK bring into focus the com- cells with some characteristics of the supercells, they do plexity of tornado formation and structure, with its not meet the definition of discrete entities as defined in plethora of vortices. Many, if not most, of these cases are the type I classification. Tornadic supercells can be in shear-driven vortices that are also capable of coalescing a line but separated (and not in a solid QLCS) and thus into a spectrum of vortex sizes. In spite of this complexity consistent with the classification criteria. and the importance of their findings, the author does not 1258 WEATHE R AND FORECA STING VOLUME 29

TABLE 1. Criteria for applying tornado taxonomy.

Tornado type Characteristics for classification label Ia Discrete supercell with mesocyclone (typically a hook echo) with supportive values of CAPE and storm-relative helicity (SRH) with low-level directional shear Ib Discrete minisupercell with low top in a low-tropopause environment; typically minimal CAPE with large SRH; more common in early spring and late fall Ic Typically in the right-front quadrant (RFQ) of landfalling hurricanes; supportive values of CAPE, low-level shear and large ambient vertical Id Anticyclonic vortices that form in close proximity to much stronger cyclonic tornadoes and within the clockwise shear zone and region of anticyclonic downdraft tilting IIa (LEWP)—a mesoscale wave pattern that adds to the local vorticity field and mesocyclone formation IIb produced by a cold pool with enhancement of the solenoidal field and tilting with increased shear IIc Bookend vortex typically at the top or cyclonic end of the bow echo with associated mesocyclone IId IJs along sections of the QLCS that add to the local shear and vorticity field and the formation of mesovortices IIe Mesovortices that develop along a QLCS that are not associated with LEWPs, bows, or IJs IIf QLCS events are typical in the outer spiral bands of a hurricane and may produce tornadoes in the RFQ at landfall; supportive values of CAPE and ambient vertical vorticity IIIa Cumuliform cloud (sometimes not glaciated) with intense local updraft that converges and stretches vertical vorticity into a misocyclone in the PBL IIIb Similar to IIIa (but over water) and typically not glaciated; not to be confused with type I and type II tornadoes over water IIIc Convective instability due to cold air aloft and favorable shear for vortex development in a cooler environment (typically does not reach the ground) see a basis for changing the taxonomy presented or the REFERENCES AMS definition of a tornado. Agee, E., and E. Jones, 2009: Proposed conceptual taxonomy for proper identification and classification of tornado events. Wea. 2. Summary and conclusions Forecasting, 24, 609–617, doi:10.1175/2008WAF2222163.1. ——, and ——, 2010: Reply. Wea. Forecasting, 25, 341–342, In summary, the author is pleased with the latest AMS doi:10.1175/2009WAF2222353.1. definition of a tornado and equally pleased to eliminate ——, C. Church, C. Morris, and J. Snow, 1975: Some synop- two tornado species from the original AJ taxonomy. tic aspects and dynamic features of vortices associated with the tornado outbreak of 3 April 1974. Mon. Wea. Also, this revision has provided an opportunity to make Rev., 103, 318–333, doi:10.1175/1520-0493(1975)103,0318: additional minor changes in the taxonomy (as suggested SSAADF.2.0.CO;2. by others in the research community). Further, a brief ——, J. T. Snow, and P. R. Clare, 1976: Multiple vortex features in discussion of the potential impact of the WK Doppler the tornado and the occurrence of tornado families. Mon. investigation of tornado-associated vortices on the Wea. Rev., 104, 552–563, doi:10.1175/1520-0493(1976)104,0552: . AMS definition has been provided. Equally important is MVFITT 2.0.CO;2. Fujita, T. T., 1974: Jumbo tornado outbreak of 3 April 1974. consideration of the study by Smith et al. (2012),which Weatherwise, 27, 116–126, doi:10.1080/00431672.1974.9931693. defines convective modes for significant severe thunder- Glickman, T., Ed., 2000: Tornado. . 2nd storms and tornadoes, based on 78.5% of all such ed. Amer. Meteor. Soc., 585. CONUS reports from 2003 to 2011. Their three cate- Huschke, R. E., Ed., 1959: Tornado. Glossary of Meteorology. gories were QLCS, supercells, and disorganized, along Amer. Meteor. Soc., 781. Markowski, P., and N. Dotzek, 2010: Comments on ‘‘Proposed with a number of subcategories such as bow echo, discrete conceptual taxonomy for proper identification and classifica- cell, cell in cluster, cell in a line, marginal supercell, and tion of tornado events.’’ Wea. Forecasting, 25, 338–340, linear hybrid. Clearly, these convective categories bear doi:10.1175/2009WAF2222343.1. a strong similarity to the tornado taxonomy classifications Smith, B. T., R. L. Thompson, J. S. Grams, C. Broyles, and H. E. (and should), but they are not the same. Brooks, 2012: Convective modes for significant severe thun- Although it has taken several decades, the newest derstorms in the contiguous United States. Part I: Storm tornado definition seems solid and is not likely to change classification and climatology. Wea. Forecasting, 27, 1114– 1135, doi:10.1175/WAF-D-11-00115.1. again. It is not viewed as being compromised by new Wurman, J., and K. Kosiba, 2013: Finescale radar observations of discoveries such as those by WK (although change is al- tornado and mesocyclone structures. Wea. Forecasting, 28, ways possible when warranted). 1157–1174, doi:10.1175/WAF-D-12-00127.1. 1494 JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY VOLUME 53

Adjustments in Tornado Counts, F-Scale Intensity, and Path Width for Assessing Significant Tornado Destruction

ERNEST AGEE AND SAMUEL CHILDS Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, Indiana

(Manuscript received 12 July 2013, in final form 30 January 2014)

ABSTRACT

The U.S. tornado record is subject to inhomogeneities that are due to inconsistent practices in counting tornadoes, assessing their damage, and measuring pathlength and path width. Efforts to improve the modern tornado record (1950–2012) have focused on the following: 1) the rationale for removing the years 1950–52, 2) identification of inconsistencies in F0, F1, and F2 counts based on implementation of the Fujita scale (F scale) and Doppler radar, 3) overestimation of backward-extrapolated F-scale intensity, and 4) a change in path-width reporting from mean width (1953–94) to maximum width (1995–2012). Unique adjustments to these inconsistencies are made by analyzing trends in tornado counts, comparing with previous studies, and making an upward adjustment of tornadoes classified by mean width to coincide with those classified by maximum width. Such refinements offer a more homogeneous tornado record and provide the opportunity to better evaluate climatological trends in significant (F/EF2–F/EF5) tornado activity. The median EF-scale

(enhanced Fujita scale) wind speeds Vmed have been adopted for all significant tornadoes from 1953 to 2012, including an adjustment for overestimated intensities from 1953 to 1973. These values are used to calculate annual mean kinetic energy, which shows no apparent trend. The annual mean maximum path width PWmax from 1953 to 2012 (adjusted upward from 1953 to 1994 to obtain a common lower threshold), however, displays an increasing trend. Also, the EF-scale median wind speeds are highly correlated with PWmax. The 2 quantity (Vmed 3 PWmax) is proposed as a tornado destruction index, and, when calculated as an annual cumulative value, the three largest years are 2007, 2008, and 2011.

1. Introduction as in available targets and objects that can be damaged, as discussed by Doswell et al. (2009), Edwards and Brooks Analyses of tornado intensities, their trends, and pat- (2010),andEdwards et al. (2013). It is well known that terns of destruction through time are of great importance maximum and the types of structures in the in the realm of climate science and to society in general. path, along with airborne debris and missiles, play a ma- Scientists can be limited, however, by a lack of cohesive jor role in causing tornado damage and as such are related statistics in the modern tornado dataset (1950–2012). to the ultimate assignment of F/EF-scale values. Thus, not Considerable attention has been given to U.S. tornado only velocity y,but alsoy 2 and y 3, are important consid- statistics to determine the distribution function for their erations in evaluating damage potential (Emanuel 2005). intensity, as well as the potential relationship of their This study specifically chooses to use y 2,sincedynamic- intensity to pathlength and path width (Dotzek et al. pressure wind loading onto barriers is directly propor- 2003, 2005; Brooks 2004). The creation of the Fujita (F) tional to the free-stream kinetic energy. There have been and enhanced Fujita (EF) scales has introduced potential efforts to improve or establish more internationally rec- impacts on the interpretation of the U.S. tornado record. ognized wind speed scales (Dotzek 2009), but there re- For example, both scales attempt to use tornado damage main opportunities to adjust for discrepancies and to to quantify maximum wind speeds, but limitations exist in create a more homogeneous record of U.S. tornado damage-assessment subjectivity and application, as well events [for 1950–2012, as archived in Storm Data (de- scribed below), which is also accessible online from the Storm Prediction Center (http://www.spc.noaa.gov/wcm/)]. Corresponding author address: Ernest M. Agee, Dept. of Earth, Atmospheric, and Planetary Sciences, Purdue University, 550 This study attempts to adjust for these discrepancies—to be Stadium Mall Dr., West Lafayette, IN 47907-2051. specific, for significant tornadoes [$F/EF2; originally de- E-mail: [email protected] fined by Hales (1988)].

DOI: 10.1175/JAMC-D-13-0235.1

 2014 American Meteorological Society JUNE 2014 AGEE AND CHILDS 1495

2000

1800 • r= 0.913 • • 1600

1400 • • • • • 1200 • .. • • • ~ • • • •• ::, 1000 • 0 u • • • •• • • • 800 • • • • • • • •• • • • • •• 600 •• •• • • 400 • •

200 •••

0 1940 1950 1960 1970 1980 1990 2000 2010 2020

FIG. 1. Annual U.S. tornado count from the NCDC Storm Data archive, obtained from the Storm Prediction Center (http://www.spc.noaa.gov/wcm/), for 1950–2012.

The proposed adjustments are based on the following: at the National Climatic Data Center (NCDC), and 1) establishing the best year for beginning the tornado currently includes tornado attributes for the period of record, 2) illustrating the heterogeneities in the F0 count 1950–2012. Numerous efforts have been made to pro- for different periods of time, 3) identifying the under- vide the most accurate data [the most recent being the counting of F1 events and the overcounting of F2 events introduction of the EF scale; see assessment by Edwards that took place prior to 1974 and revising to establish a et al. (2013)], but there remain succinct biases in a num- more homogeneous record, 4) making adjustments to in- ber of the attributes, some of which have been addressed flated F-scale values (and thus speed estimates) from prior (Schaefer and Edwards 1999; McCarthy 2003; Doswell to 1974, and 5) establishing a more complete tornado re- 2007). Specifically applicable to this study are biases that cord for maximum path width, recognizing that mean exist in both reported count and damage magnitude of tornado path width was recorded in the years prior to 1995. tornadoes throughout the period that inhibit accuracy of Upon finding and implementing adjustments to the analysis and/or require the omission of large portions above, the opportunity exists to reexamine tornado in- of the data record to avoid such biases. Differences in tensity trends through time, particularly in significant path-width reporting (from mean to maximum) are also tornado counts, their kinetic energy, and maximum path addressed. width (as well as the possible relationship of the median a. Homogeneous versus heterogeneous records EF-scale wind speed value with maximum path width). Further, to provide a way to better assess the magnitude One of the concerns to be examined is associated with of tornado damage on the basis of F/EF-scale wind speed the first three years of the modern tornado data record: estimates, this study introduces a tornado destruction 1950–52. Efforts to extend the tornado record back in index (TDI). It is noted that this index does not explicitly time to before the establishment of the National Severe consider the geography of population distribution and Storms Forecast Center in 1953 have been pursued with construction practices along the path of individual tor- support from the U.S. Nuclear Regulatory Commission nadoes. Analysis of the annual cumulative values of the (Tecson et al. 1979) and independently by Grazulis

TDI parameter (TDIC) is also made to look for evidence (1993). These efforts involved searching newspaper re- of climatological trends and/or idiosyncrasies in archiving ports and old photographs—useful but limited resources method. that may not allow for accurate tornado attributes (Doswell and Burgess 1988; Schaefer and Edwards 1999). Figure 1 shows the annual tornado count through time, 2. Data accountability, adjustments, and analysis which has been increasing since 1950 as a result of a va- The Storm Prediction Center maintains a modern tor- riety of factors (population growth, increasing numbers nado data record, compiled from the Storm Data archive of storm chasers and observers, verification methods, 1496 JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY VOLUME 53

1400

1200 C ..,0 'E' 1000 ~ • .,> l //:,/ ..0 ..0 • 800 ~ ~ ...... • • L.. ..- • ~ • ...C .,C -[ ~...... • :::, OD .. . 0 I ..: g- :•• • V II ••• .,t>O 0 r···························· . 600 0:: ······· .,:...... •... u • ::, z 400 vi :j • •••••• • • • • III 200 • ••• • • • •••• • • • • • • •• •• •••• • 0 ••: 1940 1950 1960 1970 1980 1990 2000 2010 2020

FIG. 2. Annual count of F/EF0 U.S. tornadoes for three heterogeneous data periods: I represents the backward extension in time from the establishment of the National Severe Storms Forecast Center in 1953, II represents the pre-Doppler period, and III represents the Doppler era. technological advancements, etc.). It is evident from this increased reporting of F/EF0 tornadoes that is largely and subsequent figures that the 1950–52 data record may due to population increase, it is noted that the magnitude have credibility issues (based in part on the assessment of the increase in the early 1990s (Fig. 2)cannotbeex - method and the long period of elapsed time in compiling plained by population growth. It is also interesting to note data). The decision to eliminate these three years of data that there is an increase in both counts and variability in from the study is discussed below, along with subsequent the F/EF0 record after the implementation of Doppler analyses that support such action. radar, as depicted by the ‘‘fanning’’ pattern of data. Another source of heterogeneity comes from improved A third area of concern, and most applicable to the tornado counting (especially for weaker tornadoes) with current study, is that of the overcounting and overrating the implementation of the Weather Surveillance Radar- the intensity of F2 versus F1 tornadoes, specifically be- 1988 Doppler (WSR-88D) network, which occurred dur- fore the implementation of the F scale in 1974, as noted ing the early 1990s and was completed in 1997 (Crum by Grazulis (1993). Figure 3a shows the F/EF1 tornado et al. 1998). Doppler radar allows for the possibility of counts from raw data files and illustrates the general detecting a vortex circulation that coincides with local undercounting of F1 tornadoes prior to 1974, as well as wind damage of F/EF0 strength. Agee and Hendricks a cluster of low values for 1950–52. The F/EF1 tornado (2011) have shown evidence of a similar technological counts from 1974 to 2012 show a more homogeneous, effect in the climatological data of hurricane-induced stationary pattern (with an average of 336 tornadoes per tornadoes. Figure 2 shows the count of F/EF0 tornadoes year), accompanied by random variability (correlation for 1950–2012 and an apparent discontinuity in the data coefficient squared r 2 5 0.0144). Contrary to the F/EF0 in the early 1990s (supported by the t-test comparison of record, no spike in reporting is seen during the time of means, significant at the 0.01 confidence level), coinciding Doppler radar implementation. Further, as seen in Fig. 3b, with the implementation of the Doppler radar network. the F2 count prior to 1974 is noticeably elevated, except This technological advancement has allowed meteorolo- for the cluster of the three years 1950–52. Coupling the gists to better detect that may produce observations of too few F1s and too many F2s for the weak tornadoes and consequently to record more events period of 1953–73, when compared with the subsequent than during the pre-Doppler era. Although Verbout et al. years, allows the authors to draw a reasonable conclusion (2006) note that nearly all of the increase in tornado that there was an assignment of excessively high values of reports during the past 50 years can be attributed to wind speed range for many of the F2 events. When all JUNE 2014 AGEE AND CHILDS 1497

(a) 700 No F-scale ' F-scale 600 ' • ' 500 -:' • - c 400 ' • :, - •• - • .• : .. • •• .. 8 300 -.... • • - - _, _. ' - .. - 200 . ....- ' • ... - • • ~.- - ' -· ' 100 r---..• • ' ~ : .___ F/EFl Homogeneity 0 ' 1940 1950 1960 1970 1980 1990 2000 -2010 2020 (b) 350 No F-scale F-scale 300 250 .... • . : C 200 • • :, ' 0 • .. ' • 150 • •• . • • u • • • 100 • •• • • ~ • 50 0 1940 1950 1960 1970 1980 1990 2000 2010 2020 (c) 1000 No F-scale . :' F-scale • 800 .... • • • C 600 :, • • 0 • • •••• • u 400 • •• •• • • • • • • • • 200

0 1940 1950 1960 1970 1980 1990 2000 2010 2020

FIG. 3. Annual counts of (a) F/EF1, (b) F/EF2, and (c) F/EF1–F/EF5 tornadoes for 1950– 2012. Noticeably low F/EF1 counts before 1974 are coupled with elevated F/EF2 counts for the same period. The three encircled years of records (1950–52) have noticeably fewer tornadoes than the pre-F-scale record. data are combined (see Fig. 3c for F/EF1–F/EF5), the completed, as noted by Brooks (2004). A method is in- record appears to be mostly homogeneous and stationary troduced below for building a maximum path width re- [as reported by Verbout et al. (2006)]. This conclusion cord from 1953 to 2012. does not follow, however, since the potentially over- estimated F2 and underestimated F1 counts have been b. Refinements and method added together, masking the real signal. 1) COUNTS As noted, the cluster of the three years 1950–52 ap- pears to be outside the distributions for particular tor- Significant tornadoes (F/EF2–F/EF5) produce the nado counts in each of Figs. 1, 2, and 3a–c, and it follows greatest destruction. In accord with this situation, it is that the authors have elected to begin their study with assumed that the contemporary significant tornado sta- 1953. Note that Verbout et al. (2006) start their analysis tistics (1974–2012) are more reliable than those from the with 1954, which is also reasonable. earlier period, because of increased knowledge, as well A fourth area of concern is the shift in the data record as more complete field investigation and documentation. for reporting tornado path width. Although there was Figure 4 is presented to show comparisons between pre- some gradual overlap of both mean and maximum path- F-scale and post-F-scale counts for equal time periods width reporting, it was not until 1995 that the change was (1953–73 and 1974–94, respectively), and it is reasonable 1498 JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY VOLUME 53

200 187.1

180

160

140 .. 120 C 5 100 u • 1953-1973 80 • 1974-1994

60

40

20 10.1 8.5 1.2 0.9 0 F2/EF2 F3/EF3 F4/EF4 FS/EFS Intensity

FIG. 4. Average annual significant tornado counts for the periods 1953–73 (pre–F scale) and 1974–94 (post–F scale). to consider making adjustments to the data. The specific from tornadoes, however (a topic discussed in a later focus is on F2 events, which account for 85% of the total section). significant tornado difference (between the two adjoining 2) INTENSITY AND WIND SPEED 21-yr periods), as previously explained in Fig. 3b.The method for adjustment (Table 1) begins with calculating Since actual maximum wind speeds of tornadoes are the mean counts of F1 and F2 tornadoes for the two pe- estimated, the approach used in this study is to adopt the riods, which establishes an F1:F2 ratio for each period. To median wind speed value Vmed (from the EF scale) for remove the overcounting of F2s in the early period, their each of the respective EF ratings of all significant tor- count is lowered (and the F1 count consequently raised) nadoes (except for the EF5 rating, where the minimum until the ratios are equal. New mean counts for F1 and F2 estimated wind speed is used because of the infrequency tornadoes are found following the adjustment, and the of events). These median wind speeds are equivalent to percent change in F1 mean counts is found to be 27.6%: the mean of the estimated wind speeds of the upper and lower bounds for that particular EF rating [e.g., for EF2 m 2 m 310 2 243 5 21 1 21 5 2 1 5 rating, Vmed (111 mi h 135 mi h )/2, converted to Count correction factor m 1 243 meters per second]. The EF scale, being a more recent 5 0:2757 / 27:6%. way to estimate tornado intensity than the F scale [see assessment by Edwards et al. (2013)], is used throughout This is the factor by which F2 counts are lowered (and F1 this study for assessing median wind speeds and calcu- counts raised) in the 1953–73 period. There was not suf- lating kinetic energy. Further, Widen et al. (2013) have ficient rationale to make comparable types of adjust- noted that the F scale and the EF scale can be considered ments to the small differences in F3–F5 tornado counts, to be equivalent for climatological studies. Not only have because of the infrequency of their occurrence (Verbout et al. 2006). The annual plot of adjusted significant tor- TABLE 1. Count-correction method for adjusting F2 tornado nado counts is presented in Fig. 5. With the adjustment, counts for 1953–73, using the more accurate 1974–94 data. the mean count of significant tornadoes for the pre-F- 1953–73 1974–94 scale era (1953–73) is lowered from 243 to 191, which is F1 mean count 243 332 closer to the mean count of 158 for the post-F-scale era F2 mean count 187 128 (1974–2012). Still, a weak decreasing trend in significant F1:F2 ratio 1.3 2.6 tornado counts exists, which is consistent with previous Corrected mean count: F1 310 332 research (Doswell et al. 2009). Fewer significant torna- Corrected mean count: F2 120 128 does does not necessarily imply a decrease in destruction Corrected F1:F2 ratio 2.6 2.6 JUNE 2014 AGEE AND CHILDS 1499

450

400

350 ie 300 ·! • • • ... 250 • • C --- • ::, ·---- •• u0 --- - ... ______4!. __• • 200 • . -·------:____ .. • 150 ••••• • • • • • • • ------~-~- • • • ••• • • ..-. --.-.-----· 100 • • • • • • 50 No F-scale -----+ .....__ F-scale 0 1950 1960 1970 1980 1990 2000 2010 2020

FIG. 5. Adjusted annual count of significant tornadoes, with linear trend in counts before adjustments (dashed line) and after adjustments (solid line). the F2 counts been revised, but also the representative maximum path width from 1995 to the present. Figure 6 median wind speeds have been adjusted (per the EF shows the annual mean values of significant tornado scale) because all counts are viewed as having over- path widths for the two periods (1953–94 and 1995– estimated wind speeds (even the fraction that is retained 2012), which reveals a discontinuity jump in their re- in the F2 category). The magnitude of the wind speed spective lower thresholds of approximately 209 m adjustment is determined by the change in percent of the (supported by a t test comparing different population total F1 and F2 counts that is attributed to F2 tornadoes means, significant at the 0.01 confidence level). In an following the count adjustment (see Table 1): attempt to equate these two different populations, mean width values have been increased by 209 m and Wind speed correction factor are renamed ‘‘maximum’’ width values. The entire re-     n n cord (1953–2012) is now represented by a single lower 5 100 F2 2 100 F2 n 1 n n 1 n threshold (as shown in Fig. 7), and the mean values of F1 F2 before F1 F2 after maximum path width for each of the four significant 5 : / : 15 6 15 6%, EF-scale ratings have been matched by making an upward adjustment of 52 m (209/4) for the period of where nF1 and nF2 are the number of F1 and F2 counts, 1953–94. The trend of path widths through time shows respectively. Thus, the principle now invoked (viz., cor- increasing variability with a recent uptick toward rection of overestimation of F2 counts as a result of a wider tornadoes; improved methods of measuring path perception of higher maximum wind speeds than what widths may be responsible for some of the variability, actually occurred) results in a 15.6% reduction in the however. median wind speed for the EF2 rating. It is reasonable to note for consistency that all significant tornado scales should receive a similar adjustment for the 1953–73 period TABLE 2. Intensity corrections made to the EF-scale intensity (Table 2). Figure 5 shows that this approach and adjust- ratings for 1953–73. ment yield more homogeneous records and stationary Velocity range Vmed Vmed Vadj 2 2 2 2 patterns than are seen in the raw data. This adjustment Intensity (mi h 1) (mi h 1) (m s 1) (m s 1) may not create the perfect set of wind speed data, but it is EF2 111–135 123 55.0 46.4 an improvement. EF3 136–165 150.5 67.3 56.8 EF4 166–200 183 81.8 69.0 3) PATH WIDTH EF5 .200 200* 89.4* 75.5*

The U.S. tornado database provides the mean path * Minimum speed is used for EF5 intensity because of the difficulty width of tornado events from 1950 to 1994 but provides in assigning a median value. 1500 JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY VOLUME 53

1400

Mean Width ------.. +------Max Width ------+ 1200 •

1000 • • I 800 • i • • • If 600 • • • • • • •• • • • • • :- • 400 • • • • • • • • • ••• • • • • • •• • • •• • • •• • • • Lower Thresholds 200 • • • • • •• I

0 1950 1960 1970 1980 1990 2000 2010 2020

FIG. 6. Significant tornado path widths for 1953–2012. Mean widths were reported through 1994, and after 1994 maximum widths became the standard.

4) MAXIMUM PATH WIDTH AND TORNADO the increased opportunity to impact more buildings of INTENSITY greater structural integrity. Minimal uncertainty in this relationship exists, as expressed by the error bars in Fig. 8, From previous results, it is now possible to examine except for EF5, which is characterized by a small number the relationship of the adjusted maximum path width to of events. Also, many tornadoes are not steady-state the median value of EF-scale wind speeds (Fig. 8). The systems, multiple vortices can be present, and the aero- linear distribution of these data points shows an ap- dynamics of surface boundary layer vortex spinup can proximately 170-m increase in maximum tornado path differ, all of which represent opportunities to produce 21 width for each 10 m s increase in Vmed (with an r value variation in maximum path width versus intensity rating. of 0.981), which is a plausible result since one might ex- It is noteworthy, however, that although this result is pect wider tornadoes to have higher ratings because of derived from a different method it is consistent with the

1400

1200 •

1000 • • • 800 • I • • • • • • lli • •• • 600 • • • • • • •• •• • • ••• • • • • • • •• • • • • • •• • • • 400 • • • • • • • •• • • • Lower Threshold 200

0 1950 1960 1970 1980 1990 2000 2010 2020

FIG. 7. Adjusted mean maximum path widths (PWmax) for significant tornadoes (see Fig. 6 for comparison). An upward adjustment of 209 m was made for each data point before 1995, which approximately matches the difference in the mean value of each period. JUNE 2014 AGEE AND CHILDS 1501

1200 y =17.132x - 751.87 r =0.981 1000

800

I ----f i 600 I~ I

T. -- 400 ------r--

200 iii ---

0 40 50 I 60 I 70 80 I ~-0 100 55.0 67.3 vmedlm/s) 81.8 89.4 (EF2/ (EF3) (EF4) (EFS}

FIG. 8. Median EF-scale wind speeds Vmed vs adjusted mean maximum path width (PWmax) for 1953–2012, with error bars at the 95% confidence level.

Weibull distribution parameters for the F scale in general, intensities are exponentially distributed over the peak as reported by Brooks (2004). wind speed squared (y 2), particularly for significant tornadoes. Even if this study had chosen the advective transport of kinetic energy (y 3), used in calculating 3. Kinetic energy and tornado destruction power dissipation, the results would provide the same Although kinetic energy and related quantities for conclusion. tornadoes have been considered in past studies (e.g., The method for calculating the annual total kinetic Dotzek et al. 2005; Dotzek 2009), the adjustments to the energy for the period of 1953–73 is presented in Table 3, U.S. tornado record presented in this study now allow which incorporates the noted adjustments (reduction in for reinvestigation of such quantities. To be specific, the F2 counts and 15.6% reduction in Vmed). In a similar focus is on kinetic energy for significant tornadoes for way, Table 4 shows calculations for the unadjusted pe- the period of 1953–2012, as well as the introduction of a riod of 1974–2012. The range of wind speeds for the new quantity for examining the TDI. respective EF-scale rating has been used for all years in establishing median values V , and the square of these a. Kinetic energy med values gives the kinetic energy per intensity rating. Mul- As discussed in the introduction, this study has chosen tiplying this value by the respective number of events per y 2 for addressing tornado damage, because of its rela- intensity rating and then summing the four (EF2–EF5) tionship to dynamic pressure buildup on obstacles to the totals gives a total kinetic energy for each period. A mean flow. Further, Dotzek et al. (2005) noted that tornado kinetic energy per significant tornado per year can then be computed, as shown in Tables 3 and 4.Using asimilar

TABLE 3. Kinetic energy (KE) calculations for 1953–73. On the 7 basis of this table, one obtains KEsig_torn 5 (1.03 3 10 )/4 5 2.58 3 TABLE 4. Kinetic energy calculations for 1974–2012. On the basis 6 2 22 6 5 2 22 7 10 m s and KEsig_torn/year 5 (2.58 3 10 )/21 5 1.23 3 10 m s . of this table, one obtains KEsig_torn 5 (2.18 3 10 )/4 5 5.46 3 6 2 22 6 5 2 22 10 m s and KEsig_torn/year 5 (5.46 3 10 )/39 5 1.40 3 10 m s . Vmed Vadj KE 21 21 2 3 21 2 3 Intensity Nraw Nadj (m s ) (m s ) (Vadj) KE N adj Intensity NVmed (m s ) KE(Vmed) KE N EF2 3929 2845 55.0 46.4 2152.96 6.13 3 106 EF2 4539 55.0 3025.00 1.37 3 107 EF3 937 937 67.3 56.8 3226.24 3.02 3 106 EF3 1289 67.3 4529.29 5.84 3 106 EF4 212 212 81.8 69.0 4761.00 1.01 3 106 EF4 298 81.8 6691.24 1.99 3 106 EF5 26 26 89.4 75.5 5700.25 1.48 3 105 EF5 32 89.4 7992.36 2.56 3 105 Totals 5104 4020 — — — 1.03 3 107 Totals 6158 — — 2.18 3 107 1502 JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY VOLUME 53

14 1974• 12

2011 10 •

t:" • • 8 • • l • • • • • ~... • • • • • • 6 • • ..." • • • "" • •• • • • • • • • . •• 4 .. • • • . .. • •• • •• • • • • • • • • •

0 1950 1960 1970 1980 1990 2000 2010 2020

FIG. 9. Annual significant tornado kinetic energy for 1953–2012, calculated from the sum of the squares of the median wind speeds for the respective EF-scale rating multiplied by the number of respective events per intensity per year.

2 approach, Fig. 9 shows the adjusted total significant well as the maximum path width (PWmax) that defines tornado kinetic energy per year for the entire record, a unit of area containing such obstacles: which is stationary (see linear-fit dashed line). This is 5 3 2 further supported by the mean kinetic energy per sig- TDI (Vmed PWmax ) . (1) nificant tornado per year being very similar (1.23 3 2 2 105 m 2 s 2 for 1953–73 vs 1.40 3 105 m 2 s 2 for 1974– As shown in Fig. 8, the magnitude of tornado destruction 2012), as shown respectively in Tables 3 and 4. Two years, at the time of maximum intensity increases as EF rating 1974 and 2011, are noted outliers, with all other depar- increases. Given that the tornado has its maximum ve- 2 5 2 tures randomly distributed from the fitted line (r locity rating Vmed as it advances across the area PWmax, 0.0026), as characteristic of a stationary time series. it is appropriate to assume that every point in this unit area is exposed to maximum local damage. It is noted b. Tornado destruction index that the outer boundaries of the maximum width area Kinetic energy trends give a sense of how the strength obviously do not receive the maximum wind speed, but of tornadoes is changing through time, but they fail to this physical property of the vortex is characteristic of all account for the trend in tornado widths, which reveals events (and the individual TDI calculations are system- how much area is being influenced and possibly damaged atically made for all events). Further, this ‘‘collateral’’ at a given point in time. As noted by Thompson and damage should be related to tornado intensity and path Vescio (1998), the potential for tornado damage should width. Therefore, a cumulative parameter for significant be related to tornado intensity, path width, and path- tornadoes can now be defined as TDIC, the cumulative length. In fact, they introduced a destruction potential tornado destruction index: index (DPI) for measuring potential damage associated 5 with a single tornado outbreak. Their index multiplies the 5  2 3 2 TDIC (NVn med ) (PWmax ) , (2) tornado intensity rating and the total area of each given n52 n n track, all of which are summed for a single outbreak and compared (e.g., Palm Sunday 1965 vs 3 April 1974). The where Nn is the number of events per rating, Vmedn is parameter for estimating the intensity of tornado de- the median EF-scale wind speed, PWmaxn is the mean struction presented in the current study is different than maximum path width per rating, and n is the EF-scale DPI and has an objective that considers all significant intensity. tornadoes on an annual basis for the entire tornado re- The annual totals of TDIC are presented in Fig. 10, cord. TDI is directly proportional to the pressure exerted which suggests a quasi-stationary pattern through 2006, by wind loading on barriers to the flow [which is pro- with 1965 holding the record for highest TDIC. It is note- 2 portional to (Vmed) for the given EF-scale intensity] as worthy, however, that three of the last six years (2007, JUNE 2014 AGEE AND CHILDS 1503

100

90

2011• 80

70 2008• <:-., 60 .5. 2007• 0 0... so • >C u • i3 40 I- • • 30 • • • •• • • • ••• 20 • • •• • • • • • •• • • • • 10 •• • • • • • • • • ••• ••• • •• • •• • • • • • a 1950 1960 1970 1980 1990 2000 2010 2020

FIG. 10. Annual distribution of TDIC for significant tornadoes (1953–2012).

2008, and 2011) have produced record values of TDIC, density, structural integrity of buildings and homes, hu- which is due in part to greater values of PWmax.The man response, and geographic differences in a multitude results in Fig. 10 show a possible trend in TDIC and the of factors can potentially affect the tornado record [see increasing variability in total annual tornado destruction. Ashley (2007) and numerous references within that Note that the ratio of significant tornadoes to total tor- publication]. In addition, Brotzge and Donner (2013) cite nadoes has gone from 7.2% in 2004 to 13.2% in 2012, several societal and cultural challenges in how the public despite the decrease in significant tornadoes (see Fig. 5). is made aware of and heeds a tornado warning. These The maximum path width may be contributing to this include personalized risk, knowledge from past experi- upturn in TDIC, however (see Fig. 10). Also worthy of ence, income differences, and feasibility of taking action consideration is the possible movement of intensity rat- to protect life and property. ings toward the middle categories (EF2 and EF3) with the The study presented here offers unique adjustments introduction of the EF scale (Edwards and Brooks 2010). to improve the analysis and interpretation of tornado

Continual monitoring of TDIC provides an opportunity data and associated statistical inferences. To be specific, to detect changes in tornado destruction on a climato- the years 1950–52 are shown to be inappropriate for in- logical time scale. clusion in the data analyses presented. Identification of inconsistencies in F0, F1, and F2 counts are found to coincide with the beginning of the F-scale method, as well 4. Summary and conclusions as the implementation of Doppler radar. The F0 counts Although several improvements to the modern U.S. prior to Doppler are noticeably low, but with Doppler the tornado record (1950–2012) have been offered in past counts are much higher with greater variability. It is and current work, issues with the tornado archive remain conjectured that higher F0 counts are largely due to the that may be difficult to address. Doswell et al. (2009) capability of detecting radar vortex structures for areas discuss a systematic underrating of tornadoes in the most of relatively weak tornado damage (that otherwise recent decade that is due to policy changes at the Na- might not have been labeled as tornadic). Next, the F1 tional Weather Service, and it is further noted that con- counts are too low, prior to the introduction of the cerns related to the EF scale have been raised by Edwards F-scale method, and the F2 counts are too high for the and Brooks (2010). Verification policies that were im- same period. Refinements have been presented that plemented during NWS modernization and the Doppler move27.6%of theinflatedF2counts downtotheF1 upgrade may also influence interpretation of the tornado category. Although previous work (e.g., Verbout et al. data. Also, attention needs to be given to societal in- 2006) states that the F1–F5 annual tornado counts are fluences on tornado statistics and the nature of damage stationary, the current work shows how this record can accounts for individual events. Factors such as population be viewed as stationary once the adjustments to F1 and 1504 JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY VOLUME 53

F2 counts are made [consistent with the findings by events in the past 6 yr (2007, 2008, and 2011). This also

Grazulis (1993)]. illustrates the potential value of TDIC in monitoring the Because of the obvious importance of significant tor- climatological trend of any increasing risk of tornado nadoes in producing death and destruction, considerable destruction, an important consideration in the climate attention has been given to these data trends for 1953– science community today. 2012. Even with the adjustments to the F2 counts before 1974, the significant tornado annual totals are trending REFERENCES down [as noted by Doswell et al. (2009)], raising the question of the possible cause for such a trend. The size of Agee, E. M., and A. Hendricks, 2011: An assessment of the cli- these destructive tornado events has also been brought matology of Florida hurricane-induced tornadoes (HITs): Technology versus meteorology. J. Climate, 24, 5218–5222, into consideration, however. From 1953 to 1994, the doi:10.1175/JCLI-D-11-00235.1. mean tornado path width was recorded, but from 1995 to Ashley, W. S., 2007: Spatial and temporal analysis of tornado fa- present it has been replaced with the maximum path talities in the United States: 1880–2005. Wea. Forecasting, 22, width. Lower thresholds for each time period have been 1214–1228, doi:10.1175/2007WAF2007004.1. identified, and an adjustment of 209 m has been added Brooks, H., 2004: On the relationship of tornado path length and width to intensity. Wea. Forecasting, 19, 310–319, doi:10.1175/ to the annual mean path width for 1953–94 (thereby 1520-0434(2004)019,0310:OTROTP.2.0.CO;2. providing a longer and more homogeneous record of Brotzge, J., and W. Donner, 2013: The tornado warning process: maximum tornado path width). This lower threshold A review of current research, challenges, and opportuni- adjustment also resulted in each of the four significant ties. Bull.Amer. Meteor.Soc., 94, 1715–1733, doi:10.1175/ EF-scale ratings having an addition of 52 m (i.e., 209/4) BAMS-D-12-00147.1. Crum, T. D., R. E. Saffle, and J. W. Wilson, 1998: An update on to their mean maximum path widths. Although significant the NEXRAD program and future WSR-88D support to tornadoes are trending down, the annual mean maximum operations. Wea. Forecasting, 13, 253–262, doi:10.1175/ path width does not show a downward trend, and in fact 1520-0434(1998)013,0253:AUOTNP.2.0.CO;2. its three highest values occur in 2007, 2008, and 2011. Doswell, C. A., III, 2007: Small sample size and data quality issues To better evaluate the destructive potential of signifi- illustrated using tornado occurrence data. Electron. J. Severe Storms Meteor., 2 (5). [Available online at http://www.ejssm. cant tornadoes (at the time of their maximum intensity), org/biblio.html.] a method was adopted to assign the median wind speed ——, and D. W. Burgess, 1988: On some issues of United States for each EF-scale rating to each tornado event from 1953 tornado climatology. Mon. Wea. Rev., 116, 495–501, doi:10.1175/ to 2012, after adjustments were made to the 1953–74 pe- 1520-0493(1988)116,0495:OSIOUS.2.0.CO;2. ——, H. H. Brooks, and N. Dotzek, 2009: On the implementation riod. A simple plot of PWmax versus Vmed shows a strong 5 of the enhanced Fujita scale in the USA. Atmos. Res., 93, 554– linear correlation (r 0.981), with an approximately 563, doi:10.1016/j.atmosres.2008.11.003. 21 170-m increase in PWmax for each 10 m s increase in Dotzek, N., 2009: Derivation of physically motivated wind Vmed. Also, the error- analysis presented supports speed scales. Atmos. Res., 93, 564–574, doi:10.1016/ the validity of this relationship. j.atmosres.2008.10.015. Considerable attention in the past has been given to y, ——, J. Grieser, and H. Brooks, 2003: Statistical modeling of tor- y2 y3 nado intensity distributions. Atmos. Res., 67–68, 163–187, , and when examining possible tornado destruction. doi:10.1016/S0169-8095(03)00050-4. 2 This study has chosen y to calculate an adjusted kinetic ——, M. V. Kurgansky, J. Grieser, B. Feuerstein, and P. Nevir, 2005: energy value for the entire period of 1953–2012, which Observational evidence for exponential tornado intensity dis- shows a stationary record (with the exception of two tributions over specific kinetic energy. Geophys. Res. Lett., 32, outliers, 1974 and 2011). The adjusted kinetic energy is L24813, doi:10.1029/2005GL024583. 3 Edwards, R., and H. E. Brooks, 2010: Possible impacts of the en- given respectively for 1953–73 and 1974–2012 as 1.23 hanced Fujita scale on the United States tornado data. Pre- 5 5 2 22 10 and 1.40 3 10 m s per significant tornado event prints, 25th Conf. on Severe Local Storms, Denver, CO, Amer. per year. Recognizing that the destructive potential Meteor. Soc., P8.28. [Available online at https://ams.confex. from significant tornadoes should consider both maxi- com/ams/pdfpapers/175398.pdf.] mum wind speed and maximum size for the total annual ——, J. G. LaDue, J. T. Ferree, K. Scharfenberg, C. Maier, and W. L. Coulbourne, 2013: Tornado intensity estimation: Past, record, a new parameter, tornado destruction index, has present, and future. Bull. Amer. Meteor. Soc., 94, 641–653, 3 2 been defined as (Vmed PWmax) . This parameter is doi:10.1175/BAMS-D-11-00006.1. calculated for a unit area at the time of its maximum in- Emanuel, K., 2005: Increasing destructiveness of tropical tensity, using the median value of the assigned EF-scale over the past 30 years. Nature, 436, 686–688, doi:10.1038/ rating. Further, the annual cumulative total of TDI (de- nature03906. Grazulis, T. P., 1993: A 110-year perspective of significant tor- fined as TDIC) has been presented to evaluate the mag- nadoes. The Tornado: Its Structure, Dynamics, Prediction, and nitude of destruction of significant tornadoes and shows Hazards, Geophys. Monogr., Vol. 79, Amer. Geophys. Union, a quasi-stationary pattern yet captures three record high 467–474. JUNE 2014 AGEE AND CHILDS 1505

Hales, J. E., 1988: Improving the watch/warning system through the Path Length) tornado tape. Preprints, 11th Conf. on Severe use of significant event data. Preprints, 24th Conf. on Severe Local Storms, Kansas City, MO, Amer. Meteor. Soc., 227– Local Storms, Baltimore, MD, Amer. Meteor. Soc., 165–168. 234. McCarthy, D. W., 2003: NWS tornado surveys and the impact on Thompson, R. L., and M. D. Vescio, 1998: The destruction po- the national tornado database. Preprints, First Symp. on tential index—A method for comparing tornado days. Pre- F-Scale and Severe-Weather Damage Assessment, Long Beach, prints, 19th Conf. on Severe Local Storms, Minneapolis, MN, CA, Amer. Meteor. Soc., 3.2. [Available online at https://ams. Amer. Meteor. Soc., 280–282. confex.com/ams/pdfpapers/55718.pdf.] Verbout, S. M., H. E. Brooks, L. M. Leslie, and D. M. Schultz, 2006: Schaefer, J. T., and R. Edwards, 1999: The SPC tornado/severe Evolution of the U.S. tornado database: 1954–2003. Wea. thunderstorm database. Preprints, 11th Conf. on Applied Cli- Forecasting, 21, 86–93, doi:10.1175/WAF910.1. matology, Dallas, TX, Amer. Meteor. Soc., 6.11. Widen, H. M., and Coauthors, 2013: Adjusted tornado probabili- Tecson, J. J., T. Fujita, and R. F. Abbey, Jr., 1979: Statistics of ties. Electron. J. Severe Storms Meteor., 8 (7). [Available on- U.S. tornadoes based on the DAPPLE (Damage Area Per line at http://www.ejssm.org/biblio.html.] Departmental Colloquium

Towards a Paradigm Shift in the Modeling of Soil Organic Carbon Decomposition for Earth System Models

Yujie He PhD Candidate

Soils are the largest terrestrial carbon pools and contain approximately 2200 Pg of carbon. Thus, the dynamics of soil carbon plays an important role in the global carbon cycle and climate system. Earth System Models are used to project future interactions between terrestrial ecosystem carbon dynamics and climate. However, these models often predict a wide range of soil carbon responses and their formulations have lagged behind recent soil science advances, omitting key biogeochemical mechanisms. In contrast, recent mechanistically-based biogeochemical models that explicitly account for microbial biomass pools and enzyme kinetics that catalyze soil carbon decomposition produce notably different results and provide a closer match to recent observations. However, a systematic evaluation of the advantages and disadvantages of the microbial models and how they differ from empirical, first-order formulations in soil decomposition models for soil organic carbon is still lacking. This study consists of a series of model sensitivity and uncertainty analyses and identifies dominant decomposition processes in determining soil organic carbon dynamics. Poorly constrained processes or parameters that require more experimental data integration are also identified. The critical role of microbial life history trait, such as microbial dormancy, in the modeling of microbial activity in soil organic matter decomposition models is also demonstrated through ablation analysis. Finally, this study also surveys and synthesizes a number of recently published microbial models and provides suggestions for future microbial model developments.

Tuesday, October 21, 2014 4:00 p.m. Room 2201 HAMP

Refreshments at 3:30 pm PURDUE Room 2201I HAMP UNIVERSITY Earth Departmental Atma eric Colloquium Plane ary Sciences

Anthropogenic Signals in InSAR

Rowena Lohman Cornell University

Remote sensing methods such as interferometric synthetic aperture radar (InSAR) allow observations of surface properties over large areas at regular time intervals. InSAR, in particular, provides information about ground deformation, properties of the ionosphere and troposphere, as well as changes in surface characteristics such as vegetation and soil moisture. As higher-quality InSAR datasets become available, the spatial scale and magnitude of signals that can be studied has continued to be refined - this also requires more rigorous analysis to ensure that all of the potential contributions to the InSAR observations can be distinguished. Here, I describe several anthropogenic signals that can be observed in InSAR, including logging, geothermal power production and mining, and focus on a magnitude 3.2 earthquake that was felt widely across the Chicago area last November. This earthquake was likely triggered by a blast at a gravel quarry, since it occurred at very shallow depth several seconds after the blast. I describe the constraints we can place on the earthquake source from InSAR and assess the consistency with seismic observations for this event.

Thursday, October 23, 2014 3:30 p.m. Room 1252 HAMP

Refreshments at 3:00 pm PURDUE Room2201/HAMP UNIVERSITY Departmental Colloquium

Giant Impacts on the Asteroid 4 Vesta

Timothy Bowling PhD Candidate

The geologically recent (~1 Gya) Rheasilvia basin on asteroid 4 Vesta is on of the most spectacular impact structures in the solar system, with a diameter nearly equal in size to that of Vesta itself. To date, much of the numerical modeling of this impact has concentrated on the morphology of the Rheasilvia basin. However, the stress wave produced by an impact of this size is capable of causing deformation at considerable distance from the basin itself. We use high resolution hydrocodes modeling coupled with a strain analysis routine in order to understand the modes and magnitudes of deformation expected globally on Vesta following the Rheasilvia impact. These simulations give insight into several interesting observations by NASA’s Dawn spacecraft. First, our results suggest that the major system of graben circling Vesta’s equator opened shortly after the passage of the Rheasilvia related impact shock wave. Secondly, we find that the deficiency of small craters at Vesta’s north pole is likely a result of antipodal focusing of Rheasilvia impact related stresses. The details behind both of these findings are dependent on material parameters of Vesta’s interior, including core strength, mantle porosity, and damage to the body from previous major impacts. By matching model output to observation, we can perform a crude sort of seismology and gain insight

Tuesday, October 28, 2014 4:00 p.m. Room 2201 HAMP

Refreshments at 3:30 pm PURDUE Room 2201I HAMP UNIVERSITY [Type text]

PURDUE UNIVERSITY Department of Earth, Atmospheric, and Planetary Sciences Colloquia – Fall 2014 Thursdays at 3:30 PM, Room 1252 HAMP (unless noted)

Sept. 4 When Engineering Geology Meets Geotechnical Engineering Gary Luce, Knight Piesold & Co., AEG President Host: West Sept. 9 The Impact of Climate Change and Agricultural Activities on Water Cycling in Northern Eurasia Yaling Liu, PhD Candidate Advisor: Zhuang Tuesday, 4:00PM, Room 2201/HAMP Sept. 11 The DOE Accelerated Climate Modeling for Energy Project Dr. Robert Jacob, Argonne National Laboratory Host: Harshvardhan Sept. 18 The Origins of Volatile-rich Solids and Organics in the Outer Solar Nebula Prof. Fred Ciesla, University of Chicago Host: Minton Sept. 25 Long-term Morphological Changes in Mature Supercell Thunderstorms Following Merger with Nascent Supercells Prof. Ryan Hastings, Purdue University Sept. 30 Making Weather and Climate Data More Usable for Agriculture Across the U.S. Corn Belt Olivia Kellner, PhD Candidate Advisor: Niyogi Tuesday, 4:00PM, Room 2201/HAMP

Oct. 2 New Perspectives on Tidewater Glacier Mass Change Dr. Tim Bartholomaus, University of Texas-Austin Host: Elliott Oct. 9 Sulfur Cycling on Mars from a Perspective of Sulfur-Rich Terrestrial Analogs Prof. Anna Szynkiewicz, University of Tennessee Host: Horgan Oct. 16 Climate Impacts and Extremes in Large Earth System Model Ensembles Prof. Ryan Sriver, University of Illinois-Champaign/Urbana Host: Wu Oct. 21 Towards a Paradigm Shift in the Modeling of Soil Carbon Decomposition for Earth System Models Yujie He, PhD Candidate Advisor: Zhuang Tuesday, 4:00PM, Room 2201/HAMP Oct. 23 Anthropogenic Signals in InSAR Prof. Rowena Lohman, Cornell University Host: Elliott/Flesch Oct. 28 Giant Impacts on the Asteroid Vesta Tim Bowling, PhD Candidate Advisor: Melosh Tuesday, 4:00PM, Room 2201/HAMP Oct. 30 Abiotic and Biogeochemical Controls on Reactive Nitrogen Cycling on Boundary Layer Surfaces Prof. Jonathan Raff, Indiana University Host: Shepson

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PURDUE UNIVERSITY Department of Earth, Atmospheric, and Planetary Sciences Colloquia – Fall 2014 (cont.)

Nov. 6 Andean Foreland Basins: A Thermochronologic Perspective on Sediment Provenance, Deformation, and Basin Thermal Histories Prof. Julie Fosdick, Indiana University Host: Ridgway Nov. 11 Profiling Developing Tropical Storm Environments Using GPS Airborne Radio Occultation Brian Murphy, PhD Candidate Advisor: Sun/Haase Tuesday, 4:00PM, Room 2201/HAMP Nov. 13 Shale Gas Development and the Environment Prof. Mark Zoback, Stanford University Host: Nowack Thursday, 4:00pm, Room 210/MTHW (joint with the Physics Dept.) Nov. 20 The Role of Monsoon Circulation on Tropopause Variability Prof. Yutian Wu, Purdue University

Dec. 4 CSI Patagonia: Tracking Glacial and Climate Dynamics over the Last Glacial Cycle Alessa Geiger, University of Glasgow Host: Harbor ,

LOOKING FOR A POSITION TO PUT YOUR LANGUAGE AND TECHNICAL SKILLS TO USE?

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5˜6PM NETWORKING WORKSHOP

6:30˜7:30PM “BRANDING YOUR MULTICULTURALISM” KEYNOTE SPEAKER

7:30˜8PM PRACTICE NETWORKING

The capacity for this event is limited and will be on a ÿrst come, ÿrst serve basis. Please RSVP to “Bilingual Career Fair Networking Event “workshop through your myCCO account starting Oct 1st 2014.

SPONSORED BY - PulcssA p PURDUE 1 aa,tMll~'!tn&~ ALUMNL AMERICA CHINA SOCIETY OF INDIANA CCO EPli!'«'!illffl,o q, illJ* Loyalty lives here.

2015 AMS Travel Grant for EAPS Graduate Students

A Travel Grant has been established by a donor to provide $500 in travel funds for an EAPS graduate student to attend and present at any American Meteorological Society (AMS) meeting. This call is for travel to AMS meetings that will be held in 2015.

For a list of AMS meetings, see http://www.ametsoc.org/MEET/index.html.

The $500 travel award is limited to EAPS graduate students who plan to make an oral or poster presentation at any AMS meeting. Students may apply in advance of their paper/poster being accepted. Should a student be awarded the travel grant and their paper/poster is not accepted, the travel monies will be forfeited and will be made available to another student (at the discretion of the award selection committee).

Students need to provide electronic files via email attachment to Kathy Kincade ([email protected]) including the cover sheet (2nd page of this document), an abstract and title of the proposed presentation, and an advisor’s letter of nomination by the required due date to be considered.

The awardee will be selected by a faculty committee appointed by the Head. Awardees must submit a travel request a minimum of two weeks before departure using the standard departmental travel procedures - see the Business Office for details. The funds will be provided as reimbursement for normal travel expenses.

The complete application must be submitted electronically to Kathy Kincade ([email protected]) by 5:00 PM on Thursday, October 30, 2014.

550 Stadium Mall Drive  West Lafayette, IN 47907-2051 (765) 494-3258  Fax: (765) 496-1210  www.eaps.purdue.edu

APPLICATION

2015 AMS Travel Grant for EAPS Grad Students

Graduate Student’s Name______

Level (circle one) PhD MS

Faculty Advisor______

Grad Program GPA (or undergrad GPA if less than one year at Purdue) ______

AMS Meeting Title______

AMS Meeting Date______

The complete application must be submitted electronically to Kathy Kincade ([email protected]) by 5:00 PM on Thursday, October 30, 2014.

P. F. Low AGU Travel Award Competition for EAPS PhD Students

The P. F. Low AGU Travel Award is sponsored by Professor Cushman to provide travel funds for one EAPS PhD student to make a presentation at the Fall (San Francisco, CA) American Geophysical Union (AGU) meeting. The award is named in honor of the late Philip F. Low, a member of the National Academy of Sciences and a pioneer in the rigorous use of thermodynamics for the study of clay-water interactions.

A travel award of (up to) $1000 will be awarded to support one EAPS student to present at the AGU fall meeting. Funds will be provided as reimbursement for normal travel expenses.

Awards will be made based on merit of the research project, as well as on financial need. Students need to electronically provide the cover sheet (see below), an abstract of the proposed presentation, and an advisor’s letter of nomination by the required due date to be considered.

The complete application must be submitted electronically to Kathy Kincade ([email protected]) by 5:00pm, Thursday, October 30, 2014.

550 Stadium Mall Drive  West Lafayette, IN 47907-2051 (765) 494-3258  Fax: (765) 496-1210  www.eaps.purdue.edu

APPLICATION

P. F. Low AGU Travel Award Competition for EAPS PhD Students

PhD Student’s Name______

Faculty Advisor______

Grad Program GPA (or undergrad GPA if less than one year at Purdue) ______

List other sources of funding and amount anticipated:

______

______

______

______

The complete application must be submitted electronically to Kathy Kincade ([email protected]) by 5:00 PM on Thursday, October 30, 2014.

Glaciation in Sweden

Study Abroad Course, May 4 – June 5, 2015 credits: Estimated maximum cost $3,000, including tuition all travel food, and lodging (university and college study abroad scholarships may reduce this cost significantly) “It was a great experience doing research on glacial landforms in the mountains!”

Interested? Please send an email asa to the instructo at [email protected] letting him know you are interested. Expressin interest is not commitment t take part i the program. This program will only be offere if there are enoug students interested. If at least six people have expresse interest by October 25th we will hol a informatio sessio to discuss the details.

Glaciation in Sweden focuses o reconstructing past glacial history base o a understanding of glacial processes combined with evidenc from landforms and sediments. It involves cours and fieldwork jointly with students taking an equivalent course at Stockholm University This course i intended for juniors and seniors majoring in geology, as well as graduate students with interests in geomorphology and Quaternary geology. The study abroad course will run from May 4th to June 5th (May 4th – May 21st in West Lafayette, May 21st to June 5th in Sweden), and will include: 1. Pre-Departure On campus lectures, readings, and assignments to provide a foundation in how glaciers work, glaciers and climat change, and reconstructin past glaciers. This will includ a small group project usin remot sensin to map glacial landforms in a field area prio to fieldwork. 2. Cultural Program. The first stage of the study abroad component wil involve learning about the history an culture of Stockholm (from Vikings to ABBA and beyond), and

learning about the life and education of Swedish students in meetings with Stockholm University students and faculty We wil also learn about the geologic histor of Stockholm and how it has shaped th cit and its history.

This phase will also allow us to get over jet lag before the field program. Betwee the fiel program an the final coursewor at Stockholm University, we will have a weekend free for additional cultural experiences. The “This experience allowed me to gain some cultural insights that Stockholm Marathon occurs this weekend, in cas this interests you. I’m not exposed to as much

3. Field Program. We wil take part in a joint field program to the southern back in the US …. my cabin” Swedish Mountains, run by Stockholm University, for five days. The field mates, three American and three SU students, all came course focuse on investigating geological evidence for past glaciation and together as strangers and left

uses advance techniques i the geosciences. This involves extende visits as great friends to field sites, observations, measurement, collection of samples, and analysis of data. We will work i small groups that include bot Purdue an Stockholm students o projects that tie into the pre-departure mapping of glacial landforms using remote sensing. 4. Project Presentations at Stockholm University. Following the field program the Purdue and Stockholm students will work together to finaliz their team projects and associated reports and will jointly deliver ora presentations on their projects at the end of the course.

Retur t the US is on June 5th however participants may choose to extend their stay in Europe to travel o their ow or i groups (not part of the study abroad).