DOCSLIB.ORG

Tropical Cyclones of Thl Eastern North Pacific and Their Effects on the Climate of the Tern Unit Ed States

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Tropical Cyclones of Thl Eastern North Pacific and Their Effects on the Climate of the Tern Unit Ed States Tropical Cyclones of the Eastern North Pacific and Their Effects on the Climate of the Western United States: A Study of Circulation Features That May Be Recorded by Tree Rings, Final Report Item Type text; Report Authors Douglas, Arthur V.; Fritts, Harold C. Publisher Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ) Rights Copyright © Arizona Board of Regents. The University of Arizona. Download date 30/09/2021 07:41:12 Link to Item http://hdl.handle.net/10150/302705 TROPICAL CYCLONES OF THL EASTERN NORTH PACIFIC AND THEIR EFFECTS ON THE CLIMATE OF THE TERN UNIT ED STATES A Study of Circulation Features That May Be Recorded by Tree Rings Final Report NOAA Contract 1-35241 Second Year Prepared by Arthur V. Douglas and. Harold C. Fritts Laboratory of Tree-Ring Research University of Arizona Tucson) Arizona 85721 Prepared for: Environmental Data Service National Oceanic and Atmospheric Administration United States Department of Commerce Disclaimer: Publication of this Technical Report does not constitute official Government approval of the report's findings or conclusions. Its contents reflect the views of the Con- tractor who is responsible for the facts and accuracy of the views presented herein, and do not necessarily reflect the views or policy of the Government. PREFACE by H. C. Fritts Dendroclimatology, the use of tree rings to reconstruct variations in past climate, is the only discipline that is presently capable ofproviding quantitative information on the yearly and decadal variations in prehistoric climate. Information about climate is contained in rings because physiological processes which control ring growth and wood properties areaffected by climatic factors. Also, rigorous procedures can be used to assure precise dating so that the exact year each ring was formed can be established with certainty even for very old trees. Such accuracy in dating allows the averaging of annual growth from many trees so that the similarities in yearly growth responses among trees are reinforced and thedifferences (usually due to non -climatic factors) are minimized in the averaging process. Such well dated and replicated proxy series of climate can be calibrated by use of multivariate techniques with the variations in certainparameters of historical climate. Transfer functions can be obtained by this procedure which may be applied to the growth amountsduring years prior to the historical rec- ords to calculate and reconstruct the past variations in the parametersof climate. However, reconstruction of a climate parameter from tree rings is of limited value if we have little understanding of the climatologicalconditions that cause the parameter to vary from one year to the next. We wish to identify not only past periods of high or low moisture but also the featuresof atmospher- ic circulation that caused the moisture to fall. This report is the first of several studies aimed at understanding the climatology affecting the trees of the North American west.Later papers will deal with other features of climate and will describe applications where varia- tions in ring widths of trees are used to reconstruct anomaliesof past climate. We hope to include estimates of anomalies in the general circulation as well as the specific climatic conditions affectingthe trees. In short, we feel confident that we have a good understanding of the prefix "dendro" and are now attempting to develop in a similar fashion anunderstanding of "climatology" We recognize that there are certain details we have overlooked, but we hope our efforts will enhance the interpretation of our tree -ring analyses in terms mean- ingful to students of climate. INTRODUCTION In an earlier paper by Douglas (1972) the summer climatology of tropical storm development is reviewed with reference to Sea Surface Temperature (SST) distribution and upper- and lower -level winds.An apparent increase in yearly storm totals recorded since 1965 is believed to be the direct result of sat- ellite detection of small, well off -shore storms. However, monthly variations in storm totals appear to be caused by anomalous SST either off Baja California or along the equator west of South America. During the tropical storm season the region of greatest storm formation is found to shift towards the northwest and then southeast. This regional variation in storm development may be caused by changes in SST and upper troposphere shearing off Baja California and in the movement of the Inter- Tropical Convergence Zone (ITCZ) off mainland Mexico. Data presented by Douglas (1972) indicate that tropical storm formation is most common during the months of July, August and September. During the latter part of August through the first part of October, tropical storms can enter the southwestern United States from either a track up the Gulf of California or up the Pacific Coast of Baja California. This report will re- view some additional circulation features associated with tropical storm activity in the eastern North Pacific. The major emphasis will be directed towards the effects of these storms upon the climatological conditions of the southwestern United States. MOVEMENT OF STORMS The percentage frequency distribution of the direction of motion for all eastern North Pacific tropical cyclones was determined for the 8 compass points and for each 5° square of latitude and longitude during the period 19+7 -1971 (figs. 1 and 2). The direction and length of the lines represent the move- -1- ,0. 147 ,o 11\ 00' IJ0 0 I3o Figure 1. -- Percentage frequency distribution of the direction of motion of tropical cyclones by 5° squares for May, June, July and August. The number in the lower right hand corner represents the number of storms observed in each square. The length of each vector gives the percentage frequency of storms moving in each 45° sec- tor centered at that direction. Dashed lines indicate that there are 2 or less observations per square. so. 10. i / t / I ; 1 1 1 1 1 16 . 6.-....1. ,.....11 8 17' 7 15 1 v 6 7-7 12 I 7 3 MO% 2j U-LAJ 50 Figure 2.--Same as figure 1 except for the months of September, October and November. ments of storms in each 5° square. Those represented by two or less storms are shown in dashed lines and the number of storms analyzed isindicated in the corner of each square. At the beginning and end of the tropical storm season, a greater variance in direction of movement of storms isindicated. During the months of July and August, there is less variance in the direction of storm movement because there is more persistent steering of the stormsby the western extension of the Bermuda high. As a result of this persistent steering current and the positioning of the major source regions of storm development (Douglas, 1972, fig. 1), the storms move in a westerly or north- westerly direction. During these same months the points of recurvature to the north or northeast generally are not encountered south of 30 °N.Earlier in the season and at the end of the season the Bermuda high islocated farther south and therefore recurvature occurs at lower latitudes. May. Very few storms have formed in May and the movement of thesestorms is not persistent in any one direction, though west -to -northmovements do appear to be common (fig. 1). June. A large number of storms have occurred during this month which marks the beginning of the period of major tropical storm activity in the eastern North Pacific. East of 120 °W most of the storms move toward the northwest, parallel to the coast (fig. I). In this same region, however, some storms do move westward. The northwest direction of movement is associ- ated with the flow on the west side of the upper-level Bermuda high. A due - west direction of movement may occur when the Bermuda high is connected with the North Pacific high and there is a resultant easterly flow in the atmos- pheric circulation over the North American tropics. A small number of storms pass west of 110 °W and north of 20 °N where cool SSTwould preclude storm forma- tion as well as foster rapid storm deterioration.The 300 mb, 200 mb and 100 mb charts for the eastern North Pacific (Sadler, 1972) also suggest that upper tropospheric shearing is encountered in June west of 115 °W. Therefore both cool SST west of 110° and upper tropospheric shearing west of 115° appear to be responsible for the scarcity of storms west of 115 °W. Storm activity in June appears to affect only those land areas south of Mazatlan (23 °N). No storms are believed to have entered southwestern United States during this month. - July. A larger number of storms are observed in July throughout the study region (Douglas, 1972, fig. 2). A westward penetration of storms south of 25 °N is most evident. This increase in westward movement is associated with the seasonal warming of the ocean to the south and west of Baja California. Renner (1963) has shown that SST increases by as much as 6° in this region from Jurie to July, and farther south, near 17 °N, SST increases by 1° or 2 °F. As a result of higher SST during July, a greater area of the eastern North Pacific becomes favorable for the development and maintenance of tropical storms. In addition to these favorable surface changes in July, Sadler (1972) has shown that the upper -tropospheric westerlies shift westward of 120 °W, thus resulting in favorable conditions (non -shearing) for tropical storms in the region south of Baja California. The movement of coastal storms in July north of 15 °N is predominantly northwesterly. Landfall of storms can occur in western Mexico, but no storms enter the western United States due to very cool SST north of 24 °N and tropo- spheric shearing over northern Baja California.
Load more

Recommended publications
  • Meteorology and Climate
    Canadian Technical Report of Fisheries and Aquatic Sciences 2667 2007 ECOSYSTEM OVERVIEW: PACIFIC NORTH COAST INTEGRATED MANAGEMENT AREA (PNCIMA) APPENDIX B: METEOROLOGY AND CLIMATE Authors: William Crawford1, Duncan Johannessen2, Rick Birch3, Keith Borg3, and David Fissel3 Edited by: B.G. Lucas, S. Verrin, and R. Brown 1 Fisheries & Oceans Canada, Institute of Ocean Sciences, Sidney, BC V8L 4B2 2 Earth and Ocean Sciences, University of Victoria, PO Box 3055 STN CSC, Victoria, BC V8W 3P6 3 ASL Environmental Sciences, 1986 Mills Road, Sidney, BC V8L 5Y3 © Her Majesty the Queen in right of Canada, 2007. Cat. No. Fs 97-6/2667E ISSN 0706-6457 Correct citation for this publication: Crawford, W., Johannessen, D., Birch, R., Borg, K., and Fissel, D. 2007. Appendix B: Meteorology and climate. In Ecosystem overview: Pacific North Coast Integrated Management Area (PNCIMA). Edited by Lucas, B.G., Verrin, S., and Brown, R. Can. Tech. Rep. Fish. Aquat. Sci. 2667: iv + 18 p. TABLE OF CONTENTS 1.0 INTRODUCTION...........................................................................................................................1 1.1 KEY POINTS ................................................................................................................................1 1.2 UNCERTAINTIES, LIMITATIONS, AND VARIABILITY .....................................................................2 1.3 MAJOR SOURCES OF INFORMATION OR DATA .............................................................................2 1.4 IDENTIFIED KNOWLEDGE AND DATA GAPS .................................................................................3
    [Show full text]
  • Weather Numbers Multiple Choices I
    Weather Numbers Answer Bank A. 1 B. 2 C. 3 D. 4 E. 5 F. 25 G. 35 H. 36 I. 40 J. 46 K. 54 L. 58 M. 72 N. 74 O. 75 P. 80 Q. 100 R. 910 S. 1000 T. 1010 U. 1013 V. ½ W. ¾ 1. Minimum wind speed for a hurricane in mph N 74 mph 2. Flash-to-bang ratio. For every 10 second between lightning flash and thunder, the storm is this many miles away B 2 miles as flash to bang ratio is 5 seconds per mile 3. Minimum diameter of a hailstone in a severe storm (in inches) A 1 inch (formerly ¾ inches) 4. Standard sea level pressure in millibars U 1013.25 millibars 5. Minimum wind speed for a severe storm in mph L 58 mph 6. Minimum wind speed for a blizzard in mph G 35 mph 7. 22 degrees Celsius converted to Fahrenheit M 72 22 x 9/5 + 32 8. Increments between isobars in millibars D 4mb 9. Minimum water temperature in Fahrenheit for hurricane development P 80 F 10. Station model reports pressure as 100, what is the actual pressure in millibars T 1010 (remember to move decimal to left and then add either 10 or 9 100 become 10.0 910.0mb would be extreme low so logic would tell you it would be 1010.0mb) Multiple Choices I 1. A dry line front is also known as a: a. dew point front b. squall line front c. trough front d. Lemon front e. Kelvin front 2.
    [Show full text]
  • Northwesterly Surface Winds Over the Eastern North Pacific Ocean in Spring and Summer
    UC San Diego UC San Diego Electronic Theses and Dissertations Title Northerly surface wind events over the eastern North Pacific Ocean : spatial distribution, seasonality, atmospheric circulation, and forcing Permalink https://escholarship.org/uc/item/62x1f76v Author Taylor, Stephen V. Publication Date 2006 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA, SAN DIEGO Northerly surface wind events over the eastern North Pacific Ocean: Spatial distribution, seasonality, atmospheric circulation, and forcing A Dissertation submitted in partial satisfaction of the requirement for the degree Doctor of Philosophy in Oceanography by Stephen V. Taylor Committee in charge: Professor Konstantine Georgakakos, Chair Professor Daniel Cayan, Co-Chair Professor Scott Ashford Professor Walter Munk Professor Joel Norris 2006 Copyright Stephen V. Taylor, 2006 All rights reserved. SIGNATURE PAGE The Dissertation of Stephen V. Taylor is approved, and it is acceptable in quality and form for publication on microfilm: ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ Co-Chair ___________________________________________________________ Chair University of California, San Diego 2006 iii DEDICATION To all who maintain the interest and exert the effort to learn iv TABLE OF CONTENTS SIGNATURE
    [Show full text]
  • J16.1 Preliminary Assessment of Ascat Ocean Surface Vector Wind (Osvw) Retrievals at Noaa Ocean Prediction Center
    J16.1 PRELIMINARY ASSESSMENT OF ASCAT OCEAN SURFACE VECTOR WIND (OSVW) RETRIEVALS AT NOAA OCEAN PREDICTION CENTER Khalil. A. Ahmad* PSGS/NOAA/NESDIS/StAR, Camp Springs, MD Joseph Sienkiewicz NOAA/NWS/NCEP/OPC, Camp Springs, MD Zorana Jelenak, and Paul Chang NOAA/NESDIS/StAR, Camp Springs, MD 1. INTRODUCTION The National Oceanic and Atmospheric The SeaWinds scatterometer onboard Administration (NOAA) Ocean Prediction Center QuikSCAT satellite was launched into space by (OPC) is responsible for issuing marine weather the National Aeronautics and Space forecasts, wind warnings, and guidance in text and Administration (NASA) in June 1999. The graphical format for maritime users operating over SeaWinds scatterometer (henceforth, referred to the North Atlantic and North Pacific high seas, and as QuikSCAT) is a conical scanning, pencil beam the offshore waters of the continental United radar operating at a Ku-band microwave States. The OPC area of responsibility (AOR) frequency of 13.4 GHz that collects the extends from subtropics to arctic from 35° West to electromagnetic backscatter return from the wind 160° East. These waters include the busy trade roughened ocean surface at multiple antenna look routes between North America and both Europe angles to estimates the magnitude and direction of and Asia, the fishing grounds of Bering Sea, and the oceanic wind vector (Hoffman and Leidner, the cruising routes to Bermuda and Hawaii. 2005). The OSVW data derived from QuikSCAT has a nominal resolution of 25 km, and post The marine warnings issued by OPC are based processing techniques have resulted in a finer upon the Beaufort wind speed scale, and fall into resolution of 12.5 km.
    [Show full text]
  • Toronto's Future Weather and Climate Driver Study
    TORONTO’S FUTURE WEATHER AND CLIMATE DRIVER STUDY Volume 1 - Overview Prepared For: The City of Toronto Prepared By: SENES Consultants Limited December 2011 TORONTO’S FUTURE WEATHER AND CLIMATE DRIVER STUDY Volume 1 - Overview Prepared for: The City of Toronto Prepared by: SENES Consultants Limited 121 Granton Drive, Unit 12 Richmond Hill, Ontario L4B 3N4 December 2011 Printed on Recycled Paper Containing Post-Consumer Fibre TORONTO’S FUTURE WEATHER AND CLIMATE DRIVER STUDY Volume 1 Prepared for: The City of Toronto Prepared by: SENES Consultants Limited 121 Granton Drive, Unit 12 Richmond Hill, Ontario L4B 3N4 ____________________ _____________________________ Kim Theobald, B.Sc. Zivorad Radonjic, B.Sc. Environmental Scientist Senior Weather and Air Quality Modeller ____________________ _____________________________ Bosko Telenta, M.Sc. Svetlana Music, B.Sc. Weather Modeller Weather Data Analyst ____________________ _____________________________ Doug Chambers, Ph.D. James W.S. Young, Ph.D., P.Eng., P.Met. Senior Vice President Senior Weather and Air Quality Specialist December 2011 TORONTO’S FUTURE WEATHER AND CLIMATE DRIVER STUDY – VOLUME 1 EXECUTIVE SUMMARY The Toronto Climate Drivers Study was conceived to help interpret the meaning of global and regional climate scale model predictions for the much smaller geographic area of the City of Toronto. The City of Toronto recognized that current climate descriptions of Canada and of southern Ontario do not adequately represent the weather that (1) Toronto currently experiences and (2) Toronto cannot rely solely on large scale global and regional climate model predictions to help adequately prepare the City for future "climate-driven" weather changes, and especially changes of weather extremes. Without the Great Lakes, Toronto would have an "extreme continental climate"; instead, Toronto has a "continental climate", one that is markedly modified by the Great Lakes and other physiographical features.
    [Show full text]
  • Postbreeding Dispersal and Drift-Net Mortality of Endangered Japanese Murrelets
    The Auk 111(4):953-961, 1994 POSTBREEDING DISPERSAL AND DRIFT-NET MORTALITY OF ENDANGERED JAPANESE MURRELETS JOHN F. PIATTx AND PATRICKJ. GOULD2 •AlaskaFish and WildlifeResearch Center, National Biological Service; and 2MigratoryBird Management, U.S. Fish and WildlifeService, 1011E. TudorRoad, Anchorage, Alaska 99503, USA ASSTRACT.--Theincidental catch of seabirdsin high-seasdrift nets was recordedin 1990- 1991 by scientificobservers on commercialsquid and large-meshfishery vesselsoperating in the North Pacific Transitional Zone. Twenty-six Synthliboramphusmurrelet deaths were recorded in the months of August through December.All but one were from the Korean squid fishery in a small area bounded by 38ø-44øNand 142ø-157øE.Five specimensof the dead birds were collected and later identified as JapaneseMurrelets (S. wumizusume).As fishing effort was widely distributedover a large area eastof Japan,these data suggestthat postbreedingJapanese Murrelets migrate north to winter in a relatively small area southeast of Hokkaido, where persistenteddies form at the confluenceof the Oyashioand Kuroshio currents.Fronts between cold Oyashiowater and Kuroshiowarm-core eddies promote the aggregationof zooplankton and pelagic fishes,which in turn may attract murrelets during the nonbreedingseason. The estimatedtotal mortality of JapaneseMurrelets in high-seas drift-net fisheriesrepresents a significantproportion of the total world populationof this rare and endangeredspecies. Received 12 October1992, accepted 4 April 1993. TrtE J•PAN•E (CR•ST•D)MVRR•t,•T (Synthli- apparentlywere killed by introducedrats (Tak- boramphuswumizusume) is the rarest member of eishi 1987, Ono 1993). The estimated total mor- the Alcidae,and its populationsare seriously talitywas 414 birds,and few breedingmurrelets threatened (Collar and Andrew 1988, Gaston are presently found in what was once a very 1992, Oho 1993, Springer et al.
    [Show full text]
  • National Weather Service Glossary Page 1 of 254 03/15/08 05:23:27 PM National Weather Service Glossary
    National Weather Service Glossary Page 1 of 254 03/15/08 05:23:27 PM National Weather Service Glossary Source:http://www.weather.gov/glossary/ Table of Contents National Weather Service Glossary............................................................................................................2 #.............................................................................................................................................................2 A............................................................................................................................................................3 B..........................................................................................................................................................19 C..........................................................................................................................................................31 D..........................................................................................................................................................51 E...........................................................................................................................................................63 F...........................................................................................................................................................72 G..........................................................................................................................................................86
    [Show full text]
  • Northeast Pacific News
    PICES Press Vol. 19, No. 2 North Pacific Marine Science Organization Northeast Pacific News by William Crawford and Stewart (Skip) McKinnell Temperatures of coastal waters of the northeast Pacific are very sensitive to anomalies in the direction and strength of regional winds. Prevailing currents have none of the inertia of western boundary currents such as the Kuroshio and Oyashio, and instead are driven by local winds and respond within days to changes in their direction. Wind anomalies that persist through an entire season will impose major changes in local water temperature and salinity, and even shift the composition of ecosystems. The past three winters have experienced huge shifts in wind speed and direction due to changes in intensity and position of the Aleutian Low (AL) pressure system. Figure 1 presents maps of sea level pressure (SLP) and sea surface temperature anomaly (SSTA) for the North Pacific in February and March of 2009, 2010 and 2011. We chose to plot SLP for February because this month was the extreme of the general conditions in these winters. Normally, the AL pressure system forms in winter in the Gulf of Alaska and extends across much of the North Pacific Ocean. In 2010, AL air pressure was extremely low, falling to 994 mbar, and the system was centred in the Gulf of Alaska. By contrast, the panels of February 2009 and 2011 reveal almost no region where SLP fell below 1008 mbar, marked by a white contour in the left panels, and this contour was centred far to the west and did not even reach the Gulf of Fig.
    [Show full text]
  • Simulated Synoptic Variability and Storm Tracks Over North
    SIMULATED SYNOPTIC VARIABILITY AND STORM TRACKS OVER NORTH AMERICA AT THE LAST GLACIAL MAXIMUM by ROBERT PAWLAK A thesis submitted to the School of Graduate Studies Rutgers, The State University of New Jersey in partial fulfillment of the requirements for the degree of Master of Science Graduate Program in Atmospheric Science written under the direction of Dr. Anthony J. Broccoli and approved by ________________________ ________________________ ________________________ New Brunswick, New Jersey JANUARY 2018 ABSTRACT OF THE THESIS Simulated Synoptic Variability and Storm Tracks Over North America at the Last Glacial Maximum by ROBERT PAWLAK Thesis Director: Dr. Anthony J. Broccoli Transient eddy activity over North America during a simulated Last Glacial Maximum (LGM) is modeled by measuring synoptic variability, Eady growth rate, and comparing daily time series distribution plots of 2-m reference temperatures. The role of transient eddies in the climate, south of the Laurentide Ice Sheet (LIS), is not well understood. Quantifying changes to transient eddy activity will assist future climate modelers who wish to simulate the climate of an ice sheet terminating in a continental interior at the mid-latitudes. A band pass temporal filter is used to isolate synoptic scale variability in a simulated LGM climate using the Geophysical Fluid Dynamics Laboratory (GFDL) coupled atmospheric-ocean general circulation model CM2.1 for both January and July. LGM climate is simulated using orbital parameters, greenhouse gas concentrations, and sea level values set to 21,000 years before present and the ICE-5G ice sheet reconstruction used as climate forcings. A control run used pre-industrial (PI) values for comparison.
    [Show full text]
  • Signatures of the 1976–1977 Regime Shift in the North Pacific Revealed by Statistical Analysis K
    Signatures of the 1976–1977 Regime Shift in the North Pacific Revealed by Statistical Analysis K. Giamalaki, C. Beaulieu, Davide Faranda, S. A. Henson, S. Josey, A. P. Martin To cite this version: K. Giamalaki, C. Beaulieu, Davide Faranda, S. A. Henson, S. Josey, et al.. Signatures of the 1976–1977 Regime Shift in the North Pacific Revealed by Statistical Analysis. Journal of Geophysical Research. Oceans, Wiley-Blackwell, 2018, 123 (6), pp.4388-4397. 10.1029/2017JC013718. hal-02334268 HAL Id: hal-02334268 https://hal.archives-ouvertes.fr/hal-02334268 Submitted on 1 Jul 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Journal of Geophysical Research: Oceans RESEARCH ARTICLE Signatures of the 1976–1977 Regime Shift in the North Pacific 10.1029/2017JC013718 Revealed by Statistical Analysis Key Points: K. Giamalaki1 , C. Beaulieu1,2 , D. Faranda3 , S. A. Henson4 , S. A. Josey4, and A. P. Martin4 We show that an extremely deep and persistent Aleutian Low have 1Ocean and Earth Science, University of Southampton, European Way, Southampton, UK, 2Ocean
    [Show full text]
  • Climate Change Impacts
    CLIMATE CHANGE IMPACTS Josh Pederson / SIMoN NOAA Matt Wilson/Jay Clark, NOAA NMFS AFSC NMFSNMFS Southwest Southwest Fisheries Fisheries Science Science Center Center GULF OF THE FARALLONES AND CORDELL BANK NATIONAL MARINE SANCTUARIES Report of a Joint Working Group of the Gulf of the Farallones and Cordell Bank National Marine Sanctuaries Advisory Councils Editors John Largier, Brian Cheng, and Kelley Higgason June 2010 Working Group Members Sarah Allen, Point Reyes National Seashore Bob Breen, Gulf of the Farallones National Marine Sanctuary Advisory Council Jenifer Dugan, Marine Science Institute, University of California, Santa Barbara Brian Gaylord, University of California, Davis; Bodega Marine Lab Edwin Grosholz, University of California, Davis; Bodega Marine Lab Daphne Hatch, Golden Gate National Recreation Area Tessa Hill, University of California, Davis; Bodega Marine Lab Jaime Jahncke, PRBO Conservation Science; CBNMS Advisory Council Judith Kildow, Ocean Economics Program Raphael Kudela, University of California, Santa Cruz John Largier (Chair), UC Davis; Bodega Marine Lab; GFNMS Advisory Council Lance Morgan, Marine Conservation Biology Institute; CBNMS Advisory Council David Revell, Philip Williams and Associates David Reynolds, National Weather Service Frank Schwing, National Marine Fisheries Service William Sydeman, Farallon Institute John Takekawa, United States Geological Survey Staff to the Working Group Brian Cheng, Gulf of the Farallones and Cordell Bank national marine sanctuaries; UC Davis Kelley Higgason, Gulf
    [Show full text]
  • Eddy-Mean Flow Interaction and Its Association with Bonin High: Comparison of July and August
    ASIA-PACIFIC JOURNAL OF ATMOSPHERIC SCIENCES, 45, 4, 2009, p. 483-498 Eddy-Mean Flow Interaction and Its Association with Bonin High: Comparison of July and August Sun-Seon Lee and Kyung-Ja Ha Division of Earth Environmental System, Pusan National University, Busan, Korea (Manuscript received 18 June 2008; in final form 7 September 2009) Abstract The intraseasonal time dependency of eddy-mean flow interaction is examined during boreal summer using the inter- annual variability of Bonin high index (BHI) for 44 years (1958-2001). The perturbation kinetic energy (PKE), localized Eliassen-Palm (E-P) fluxes and barotropic energy conversion (BEC) are analyzed with a comparison in July and August. The results in strong July (SJ) years (> 1.0σ in normalized BHI) show that the 200 hPa PKE, particularly PKE of high frequency (HF; 2-9 day) eddy, is enhanced along the westerly jet, while eddy activities are reduced over the western North Pacific. This implies that the strong Bonin high is related to the weak eddy activity over that region. The meridional shear of strong westerly jet associated with the BEC from eddy to basic flow makes anticyclonic circulation over the south of Japan. In terms of the localized E-P flux, eddies tend to accelerate and decelerate the westerly flow over the north and south of the East Asian jet, respectively. Consequently, the barotropically unstable effect by the meridional shear of time-mean zonal flow and the deceleration of mean westerly flow by actions of transients are responsible for the anti- cyclonic circulation over the south of Japan in SJ years.
    [Show full text]