Minutes of the Aqua Science Working Group Meeting

March/April 2001 • Vol. 13 No. 2

GPS. The latest word is that the Flight Planning Board meets on February 8 and will likely slip Jason/TIMED Minutes of the Aqua Science to August. Meanwhile, a commercial Boeing launch called Earthwatch is Working Group Meeting sliding into the October slot. ICESat has a December slot and Iridium has moved to March 2002. If Aqua does — Steve Graham ([email protected]), Aqua Outreach Coordinator — Claire Parkinson ([email protected]), Aqua Project Scientist not launch in September/October 2001, then it will likely be early 2002.

Parkinson thanked Sabelhaus and indi- cated that the Aqua mission is fortunate in having someone of Sabelhaus’s experience and caliber available for taking over the Project Manager’s job. She then mentioned that Volume 2 of the EOS The Aqua Science Working Group met Data Products Handbook is now at the Goddard Space Flight Center available and copies can be obtained (GSFC) on February 8, 2001, chaired by Sabelhaus from [email protected] or by Claire Parkinson, the Aqua Project Sci- then gave an phoning Lee McGrier at (301) entist. Parkinson opened the meeting update on the status of 867-2037 or Steve Graham at (301) at 8:30 a.m. with a welcome and the the Aqua launch, noting that 867-2036. In addition, the AMSR-E logo announcement that George Morrow, the there are three units on the and brochure have been printed and are Aqua Project Manager, will be leaving spacecraft that are currently causing being distributed. the Aqua project on February 9 and concerns: the Formatter Multiplexer will be replaced by Phil Sabelhaus. Par- Unit/Solid State Recorder (FMU/SSR), Following Parkinson’s comments, kinson elaborated on the critical work the transponder, and the transponder Ramesh Kakar, the Aqua Program Sci- performed by Project Managers and interface electronics (TIE). The Aqua TIE entist at NASA Headquarters, spoke thanked Morrow for all he has done will be removed from the spacecraft about the recompetition of the Terra and to ensure that the mission will reach and sent back to B. F. Goodrich for Aqua science teams. The present science the objectives laid out by the scientists. inspection, because a similar Aura TIE team contracts run out on December 21, Morrow then explained that he has has recently failed vibration testing. 2001, and Procurement may or may not greatly enjoyed working on the Aqua The system Comprehensive Perfor- allow contract extensions beyond that mission but has decided to take a job mance Test (CPT), scheduled to start date. A new NASA Research Announce- with Jackson and Tull, a private aero- February 8, was delayed to allow time ment (NRA) for recompeting the team space company, as Vice President for to complete the procedure dry runs; the efforts is under development, with Jim their Aerospace division. He thanked current estimated start date is February Dodge and Jack Kaye (both of NASA everyone for working with him and 14. [Editors note: The Dry Run System CPT Headquarters) working on it. It is noted that he will be present at Vanden- was successfully completed on March 6. No expected that the new NRA will recog- berg Air Force Base with many others to new signifi cant hardware issues were identi- nize three broad categories: algorithm watch the launch of Aqua. fi ed.] Additional problems include paint maintenance, science data analysis, and cracking on the Earth shade on AIRS forward compatibility. Kakar noted that Morrow then introduced Phil Sabelhaus and excess oil in the CERES deployment the sum of funding in the three cat- as the incoming Aqua Project Manager. mechanisms. The latter problem is being egories would approximate the avail- Sabelhaus offered a brief history of his addressed by placing the deployment able funding in the science team funding involvement with NASA Earth Science mechanisms in a thermal chamber at an line. missions, including Project Manager of elevated temperature in order to bake TOMS/EP, TOMS on ADEOS, GOES, out the excess oil. It is not clear at this time if separate Landsat, Aura, and VCL. He is happy NRAs will be needed for the two plat- to have the opportunity to be involved Sabelhaus noted that the Delta Launch forms or if one will suffi ce. It is possible with the Aqua mission, especially at this Manifest is fi lling up and is crowded that an NRA for Terra will be released critical and exciting stage, and is com- in the June/July timeframe with Jason/ this summer and the new NRA for Aqua mitted to the mission’s success. TIMED, MAP, Genesis, Geolite, and (concentrating on AIRS/AMSU-A/HSB

3 THE EARTH OBSERVER

and AMSR-E) could appear approxi- CERES Team MODIS Team mately one year after launch. Rather than going into more detail, Kakar Barkstrom then relayed his experience Parkinson then introduced Vince Salo- deferred to Jack Kaye, who was at the with fi rst light images from Terra and monson, the MODIS Science Team afternoon session to expand upon these offered thoughts on possible fi rst light Leader, to present initial results from the issues. images from Aqua. Barkstrom noted Terra MODIS and thoughts on possible that it is not premature to start now fi rst light images from Aqua. Salomon- Next, Kakar offered an introduction preparing for the fi rst Aqua press con- son noted that MODIS is performing to the NASA Earth Science Enterprise ference. The audience to keep in mind well in terms of spatial, spectral, radio- Research Strategy (2000-2010), noting when preparing images is the general metric, geometric, and quantization per- that it should be a guiding strategy for public. Word charts and bar charts formance. All major systems are work- the next decade and that it is based on should be avoided, and the images ing, the focal planes and bands are the following fi ve questions: should be kept simple. well registered and are performing (overall) better than specifi cations, and The Aqua Working Group, or its spokes- • How is the global Earth system calibration looks good. Also, noise and person, needs to decide on the main changing? other factors have been identifi ed and Aqua story to present during the press reduced, leading to a useful state for conference. At the Terra press confer- • What are the primary forcings of the scientifi c use. Finally, studies are con- ence, the main story centered on atmo- Earth system? tinuing to further optimize Level 1B spheric aerosols. It would be helpful to data. Salomonson also noted that there have movies and animations detailing • How does the Earth system respond are 5 MODIS direct readout stations in the concepts, as opposed to still images. to natural and human-induced the U.S., and 25 stations or more are changes? Barkstrom noted that moderately expected to be in place worldwide soon. acceptable formats are global images • What are the consequences of with recognizable features (geography) Regarding Level 1B improvement areas, changes in the Earth system for that are visually interesting. He posed the following Terra MODIS characteris- human civilization? the question of whether or not the U.S. tics have been fi xed or improved on the should be in the center of the visuals. Aqua MODIS: • How well can we predict future Also, Barkstrom praised the MISR team changes in the Earth system? as having done the best preparations for • radiance versus scan-angle response the Terra press conference. Their work for the thermal emissive bands; Under these primary questions, there is a good model to follow for the Aqua are 23 additional questions focusing on press conference, with video sequences • optical cross-talk from band 31 (11 specifi c research areas. Kakar pointed and well-rehearsed responses. µm) into bands 32 (12.0 µm) through out that 6 of the 23 questions concern 36 (14.3 µm); the global water cycle. Lastly, Kakar The Public Affairs Offi ces at NASA reviewed the current missions and Headquarters and GSFC will have the • electronic cross-talk amongst bands launch schedule. primary responsibility for orchestrating 5-7 and bands 20-26; and the press conference. It is anticipated “First Light Images” and Science that we will use the services of the GSFC • non-uniform digital count bin-fi ll Team Presentations Scientifi c Visualization Studio and Earth factors, particularly for bands 31-36. Observatory team and should begin two Next, Parkinson explained the impor- to three months prior to the fi rst press Salomonson showed a chart summariz- tance for NASA public relations of conference rehearsal in order to perfect ing the operational characteristics of the getting good “fi rst images” to show the image formats and color scales. Terra MODIS since “fi rst light” in Febru- publicly a few months after launch Based on the Terra experience, it will ary 2000. Several problems have been and mentioned that Bruce Barkstrom probably require about three iterations stabilized starting in the fall of 2000. The and Vince Salomonson, the CERES before the images are suitable. Also, the MODIS Characterization Support Team and MODIS Team Leaders, respectively, teams should expect to do a complete is now looking at making quantifi ed have been through this process in 2000 rehearsal at an IWG prior to the press estimates of the overall uncertainty in with the Terra spacecraft. conference. the Level 1 product. Preliminary estimates show that the uncertainty is being reduced with time and has reached planned levels for Bands 4 and 5. In

4 March/April 2001 • Vol. 13 No. 2

the thermal infrared bands (particularly data by the GSFC DAAC are approx- Salomonson commented on the near- the sea surface temperature bands at 11 imately 1%. The DAAC is processing term challenges facing the science team, and 12 µm) the performance has not Terra at 2X on Silicon Graphics Origin including work to improve the Level reached adequate levels but is improv- 2000s, and is expected to reach 3X with 1B products, to optimize the use of the ing as more efforts continue to reduce the addition of the remaining Aqua products by the scientifi c community, the various uncertainty factors. hardware and installation of the S4P and to maximize the publication and on the Origins to support reprocessing. oral presentation of recent results. The Commenting on the overall status of the MODAPS is shipping 300 GB per day to team is working to fi nd and implement science products, Salomonson said that the DAACs, and 167 TB of MODIS prod- effi ciencies in the processing, reprocess- ~40 products are currently in develop- ucts have been archived at the GSFC, ing, archiving, and distribution of the ment. Most of the products have been EROS Data Center, and National Snow data. released in Beta format for examination and Ice Data Center DAACs. by the scientifi c community, starting in Lastly, Salomonson commented on fi rst the fall of 2000. Work continues on all A MODIS User Survey was conducted light images from Aqua. The present the products to get them to the point at the Fall 2000 AGU meeting. The understanding is that fi rst light for where they can be considered routinely goal of the survey was to address MODIS will occur 39 days after launch, useful for scientifi c or applications whether or not MODIS data distribution versus 68 days after the launch of studies. It is suggested that anyone is lower than it should be. Roughly 350 Terra. In the Terra MODIS case, needed wishing to employ the MODIS products people from fi elds ranging from edu- outgassing/purging did not occur suf- should communicate with the appropri- cation (K-12 and college introductory fi ciently, and actions were necessary to ate MODIS Science Team member to remote sensing courses) to atmospheric eliminate icing on the radiative cooler in ascertain the utility of the product or, at and oceanographic research participated August 2000. The current perception is least, should pay careful attention to the in the survey. The reasons for not order- that the Aqua MODIS schedule is too quality “fl ags” on the products. Addi- ing MODIS data can be grouped into fast, and MODIS fi rst light should prob- tionally, the MODIS Web pages contain four categories: ably occur closer to 50 days after launch. much useful material on quality assur- However, the MODIS Science Team is ance and validation efforts for the prod- 1. Data Maturity - Several people indi- ready to work with the Project to ucts. In general, use by the scientifi c cated that they would wait for more better understand the plans and trade- community is encouraged so as to mature data products because of offs. Salomonson mentioned the impor- obtain feedback and hasten validation. resource limitations. (This is typical tance of using common words rather for new data products.) than scientifi c terms at the “fi rst light” MODIS-associated data processing sys- press conference and of having a central tems (i.e., the GSFC DAAC and the 2. Data Access - Several people had theme. MODIS Adaptive Processing System experienced diffi culties with order- [MODAPS]) reached stable global pro- ing data and have not tried again. AIRS/AMSU-A/HSB Team duction in fall 2000 and are consistently (Information needs to be distributed ingesting, processing, archiving, and regarding the improvements in data After a short break, George Aumann, distributing data. The data systems access.) the AIRS Project Scientist, offered a are resource-constrained and effi ciencies status update on the AIRS/AMSU- in hardware, systems, software, algo- 3. Data Subsetting (spatial, temporal A/HSB program. The AIRS/AMSU-A/ rithms, and even products are being and parameter) - The transfer of HSB instruments have been integrated evaluated. While hopeful for additional large data fi les is diffi cult. Several on the Aqua satellite at TRW for resources, all avenues are being pursued users would fi nd the data more the last six months, and many of for producing consistent, timely data manageable if vertical profi les of the comprehensive performance tests sets. A goal is to produce a consistent, selected parameters for specifi ed (all with spectrometer and detectors at one-year data set starting sometime in geographical regions were available. ambient temperature) have been com- 2001. This effort may begin in June 2001, (Subsetting/data mining efforts are pleted. AMSU-A and HSB time code using the best performing algorithms taking place.) issues in the packets are currently being available at that time. It will cover the resolved. The pre-thermal vacuum scan period from November 2000 to Novem- 4. Data Formats - Some users mirror inspection is scheduled for Feb- ber 2001. expressed concern about the data ruary 18. The thermal vacuum test itself only being available in HDF-EOS will allow testing of AIRS detectors at Regarding production status, EDOS is format. (Use of data format transla- the in-orbit temperature of 60 K. working well and reorders of Level 0 tors is being considered.)

5 THE EARTH OBSERVER

Regarding software status, AIRS Prod- 1B, cloud-free data. The AIRS science shows a rainfall decrease during the uct Generation Software (PGS) version team will assist with cloud-free iden- warm phase, perhaps due to changes in 2.1 has been delivered to the GSFC tifi cation, cloud-cleared radiance utili- drop size distribution. DAAC, and version 2.1.5 (the last pre- zation, and the forward and tangent launch PGS delivery) will have the model. The next workshop is scheduled Regarding AMSR-E fi rst light images, fi nal interfaces frozen, plus additional for May 2001. Lobl noted that AMSR-E has a strong Quality Assurance indicators. Level 1B heritage and thus the only new mea- software has been revised based on Some initial thoughts on possible fi rst surements to be highlighted are the data from the Lockheed Martin thermal light images from AIRS/AMSU-A/HSB highest spatial resolution passive-micro- vacuum chamber and has been docu- presented by Aumann include: wave data yet in the extratropics (the mented in the Level 1B Algorithm Theo- TRMM Microwave Imager has similar retical Basis Document version 2.2i. • animation of a global map going resolution in the tropics) and the highest from the top of the atmosphere to 6 GHz resolution yet (50 km vs. SMMR’s Global simulated software has been the surface to illustrate global tem- 120 km). Possible fi rst light images used for software development, incor- perature soundings; include extratropical imagery of rain porating real instrument noise and spec- systems over the land and ocean, sea tral characteristics. The global data fi eld • animation of global maps of several ice, soil moisture, snow cover, oceanic has been based on National Centers days of total water from AMSU to wind fi elds near deep low pressure for Environmental Prediction (NCEP) illustrate water transport; and systems, global imagery of sea surface Aviation forecasts including multi-layer temperature (even through clouds), and clouds, liquid water, surface emissivity, • animation of several days of global improved spatial sampling of rainfall. and surface temperature. A “golden images from an upper tropospheric day” exercise was completed over the sounding channel to illustrate After Lobl, Yasuyuki Ito, the ADEOS-II period January 22-25, 2001. This exercise “water wind.” Science Project Manager at the Earth involved testing the data fl ow, display, Observation Research Center (EORC) retrieval and analysis software. The A special section in the Journal of Geo- of the National Space Development team is currently analyzing the data. physical Research with fi rst results from Agency of Japan (NASDA), presented a AIRS/AMSU-A/HSB is being planned, status update on ADEOS-II and AMSR- Regarding validation activities, the AIRS with refereed papers from each AIRS E/Aqua, plus thoughts on possible fi rst team is working towards the original Science Team member. The papers light images. Ito began with a brief over- schedule of DAAC delivery of validated would be submitted at Launch + 12 view of the Earth observation satellite PGS by Launch + 12 months. Validation months, but will be in print no sooner programs of Japan, including a break- support teams will be integrated into the than 10-12 months after submission. down of the organization of the Offi ce of plan as soon as the teams are offi cially Earth Observation Systems. selected. AMSR-E Teams Next, Ito provided a status update on Aumann reiterated the challenge set Following Aumann, Elena Lobl pre- the ADEOS-II program. The ADEOS-II forth by James Baker of NOAA and Dan sented on behalf of Roy Spencer, the system Proto-Flight Test was completed Goldin of NASA to demonstrate AIRS U.S. AMSR-E Science Team Leader. Lobl in December 2000, and the satellite will data assimilation impact by Launch + noted that the AMSR-E Science Inves- be stored by the end of March 2001. 12 months. To that effect, a workshop tigator-led Processing System (SIPS) Functional tests and additional tests on was held on December 6, 2000, and was should be ready for the Mission Opera- the satellite’s sensors will be conducted, attended by representatives of NCEP, tions Science Systems-2 test. Lobl then with a Post Qualifi cation Review to be the European Centre for Medium-Range described a passive-microwave rainfall held by the end of March 2001, aiming Weather Forecasts, the UK Met. Offi ce, mystery, wherein various estimates of towards a February 2002 launch target. the Canadian Meteorological Center, tropical ocean rainfall change during and the GSFC Data Assimilation Offi ce El Niño Southern Oscillation (ENSO) The AMSR-E fl ight instrument is under- (DAO). The operational data link via (+10% during the warm phase) are at going a systems test aboard the Aqua NOAA’s National Environmental Satel- least double those inferred from surface spacecraft at TRW, while the Level 1 lite Data and Information Service is in energy and atmospheric radiation bal- data processing system is undergoing place and is currently producing daily ance considerations. Possible explana- its fi rst mission simulation test. The AIRS/AMSU-A/HSB “data” using the tions for these differences include rain- second mission simulation test will be NCEP Aviation forecast model. The cur- fall effi ciency and changes in drop size conducted from April to July 2001. Also, rent data assimilation uses only Level distribution. The TRMM radar actually the Level 2 and 3 data processing system

6 March/April 2001 • Vol. 13 No. 2

is in the manufacturing and test phase. Level 3 images on water vapor, sea sur- to MODIS-Land (see http:// face temperature, and other variables, modarch.gsfc.nasa.gov/MODIS/), Regarding data distribution for and, if feasible, animations using Level there will be a strong emphasis ADEOS-II and AMSR-E, the Earth 1B and/or Level 2 data. on piggyback validation activities Observation Center (EOC) will be the with AERONET and FLUXNET. receiving, archiving, processing, and Discussion MODIS-Ocean will conduct an distributing center while the EORC will AVHRR pathfi nder/MODIS com- serve as the algorithm development and Following Ito’s presentation, Parkinson parison, conduct cruises with a calibration/validation center. Validated led a brief general discussion on Aqua marine interferometer, and utilize Level 1 and Level 2 data will be avail- fi rst light images, including possibilities the MODIS Ocean Buoy. MODIS- able at the EOC 12 months after launch, for highlighting, such as improved Atmosphere will utilize land valida- but PI’s will have access to the non-val- resolution, morning/afternoon tion sites and fi eld campaigns such idated data before their public release. contrasts, and the full hydrological as ARM, AERONET, FIRE-ACE, and NASDA and NASA will implement cat- cycle. Barkstrom noted that we need SAFARI. alog, browse, and order interoperability to move beyond highlighting high-res- for the ADEOS-II phase. olution images and show how these • Bruce Wielicki reported on the data can affect people’s lives. He also CERES Team’s calibration and vali- Ito noted that geophysical products mentioned that it would be helpful to dation efforts for the Terra CERES from the Global Imager (GLI) on stress the combination of instruments and the TRMM CERES. Most CERES ADEOS-II will include aerosol param- and their technical differences. Bruce validation makes use of long-term eters, cloud parameters, chlorophyll-a, Wielicki of the CERES Team added that validation sites such as ARM, BSRN, colored dissolved organic matter, sus- the images should focus on a common and AERONET sites for clouds, pended solid weight, sea surface tem- theme, such as the water cycle. Aumann aerosols, and surface radiative perature, vegetation index, and snow mentioned that television weather fore- fl uxes. Current CERES fi eld plans grain size and impurities. Additionally, casters are now claiming a 5-day accu- include the CERES ARM Validation the SeaWinds sensor will measure sea racy and that there is a large public Experiment (CAVE), the Chesapeake surface wind vectors, while the Polar- awareness of this, leading to the sugges- Lighthouse and Aircraft Measure- ization and Directionality of the Earth’s tion that maybe we should highlight the ments for Satellites (CLAMS), sched- Refl ectances (POLDER) will measure impact that Aqua will have on weather uled for July 12 - August 1, 2001, and clouds and aerosol parameters, and the forecasting. It was also noted that many the CERES Ocean Validation Experi- Improved Limb Atmospheric Spectrom- of the topics could be the same as those ment (COVE). The CERES fi eld val- eter II (ILAS-II) will measure ozone and in the upcoming Aqua Science Writers’ idation plans are detailed on the CERES Web site at http://www- HNO3. The geophysical products from Guide. AMSR on ADEOS-II and AMSR-E on cave.larc.nasa.gov/cave/. Aqua include cloud water, water vapor, Validation precipitation, sea surface wind speed, • Eric Fetzer explained that on-orbit sea surface temperature, sea ice, snow Following the general discussion, Peter validations for the AIRS Team will depth, and soil moisture. Hildebrand, the Aqua Deputy Project focus strongly on operational rawin- Scientist for Validation, presented a sondes and dedicated radiosondes There was an AMSR PI meeting in summary of the Aqua Validation Work- at times of overpass, plus observa- Kyoto, Japan from October 30 to ing Group meeting held at GSFC on Feb- tions of the marine surface state November 1, 2000 and a joint U.S./ ruary 7, 2001. In attendance at the Feb- from buoys. Soundings will come Japan AMSR/AMSR-E, team meeting ruary 7 meeting were approximately 20 from ARM-CART validation sites, held in conjunction with an Inter- participants from the MODIS, CERES, Brazil, and Australia. Fetzer noted national Geoscience and Remote Sens- AIRS, and AMSR science teams. At the that the full validation plan is on ing Symposium in Honolulu in July meeting, validation plans for each Aqua the AIRS Web site, http://www- 2000. Currently, an AMSR/AMSR-E PI instrument were reported on by instru- airs.jpl.nasa.gov/. meeting is tentatively planned for the ment team representatives. In summary: November 2001 to January 2002 time • Elena Lobl noted the AMSR-E Web frame. • Vince Salomonson reported the site at http://wwwghcc.msfc. MODIS Team’s scheduled com- nasa.gov/AMSR/. AMSR-E ocean Ito suggested, as possible fi rst light parisons with other satellites, product validation will utilize buoy, images from AMSR-E, a selection of ground measurements and science radiosonde, and satellite observa- high-resolution Level 1B images and campaigns, and models. Specifi c tions. Sea ice product validation will

7 THE EARTH OBSERVER

use ship and aircraft campaigns, as siderable interest in the formation-fl ying initial orbit phasing relative to the morn- well as MODIS and Landsat obser- concept at NASA Headquarters and that ing constellation must be considered vations. Rainfall products will be his term for the afternoon satellite for- to avoid ground station confl icts with validated through several fi eld cam- mation is the “A-Train”, with Aqua those spacecraft. Aqua will need to time paigns using a ground X-band radar at the lead and Aura at the tail. He the ascent maneuvers so that after it and data from the Eureka and the showed an impressive animation of the reaches its fi nal orbit position, it will not Kwajelein radars, plus comparisons A-Train in orbit and mentioned several fl y over the polar ground stations at the with the TRMM Precipitation Radar important complementarities amongst same time as other spacecraft. The pre- and the TRMM Microwave Imager. the instruments on the fi ve A-Train sat- liminary Aqua ascent plan to 705 km Snow products will be validated on ellites. consists of four maneuvers to be com- 25-km grid, regional, and river basin pleted by day 14. The synodic period scales using aircraft observations. Schoeberl then introduced Rich Macin- between spacecraft at 695 km and 705 Soil product validation will utilize tosh and asked him to review formation km is 32 days; this is the maximum time many land surface hydrology experi- fl ying requirements and the Aqua we would have to wait for proper initial ments around the globe, modeling requirements for initial orbit phasing. phasing before starting ascent maneu- and data assimilation, and compari- Formation fl ying of Aqua with Aura vers. sons with AIRS and MODIS. requires that both spacecraft must maintain a ground track on the World Refer- If Aqua is required to phase with the Hildebrand noted that common themes ence System (WRS) using frequent burns morning constellation, the time needed surrounding Aqua validation plans (once every three months) to counteract to perform the ascent to mission altitude include the upcoming announcement atmospheric drag. A ground track con- could increase signifi cantly depending concerning the pending Aqua validation trol of ±20 km results in minor varia- on the initial phasing at launch. The proposals and the expected recompe- tions in spacecraft separation of ±43 sec- best-case scenario has an initial phasing tition of the science team efforts. The onds along-track. The largest effect on at launch that allows the fi nal desired next steps for the Aqua Validation the spacecraft separation over time is position to be achieved with no changes Working Group will be to evaluate from the difference in ascending node to the nominal maneuver plan. The the common validation needs and to mean local time (MLT) between the worst-case scenario has an initial phas- develop common calibration/validation two orbit planes. While both spacecraft ing at launch that requires a delay of venues. The next meeting will take maintain their ground tracks, separation one synodic period before starting the place on August 1, 2001, the day before will change gradually as the MLT ascent. In the latter case, 32 days would the next Aqua Science Working Group changes. be added to the 9-day maneuver period, meeting. for a total of 41 days. However, from Both spacecraft must perform occasional the Terra experience, this would not nec- During the validation discussion, inclination maneuvers to control MLT essarily preclude instrument operation Wielicki pointed out the need to sort drift so minimum desired separation (on during the ascent period. out the defi nitions of beta versus provi- the order of 15 minutes) is not violated. sional versus validated data products. The Aqua MLT is allowed to range from Wayne Esaias, the MODIS-Ocean Group Salomonson agreed, adding that it is 1:30 p.m. to 1:45 p.m., while the Aura leader, offered the suggestion that in probably an issue most appropriately MLT is allowed to range from 1:30 addition to formation fl ying of the addressed by the EOS Investigators’ p.m. to 2:00 p.m. Aqua and Aura A-Train we should look into the pos- Working Group. must agree on desired MLT ranges sibility of having the daytime path of to maintain separation; this implies an the Aqua MODIS match the previous or Formation Flying of the EOS agreement on the frequency of incli- next nighttime path of the Terra MODIS. Afternoon Satellites nation maneuvers. Smaller MLT range implies smaller, more frequent inclina- The next speaker, Bruce Wielicki from After the lunch break, the meeting tion burns—1 or 2 per year versus 1 or 2 the CERES Team, continued with the reconvened at 1:30 p.m. with Parkinson over the lifetime of the mission. formation-fl ying theme by elaborating introducing the next set of three talks, on the synergisms of the train. Wielicki all centered on the issue of formation Macintosh noted that, during the ascent reiterated that the A-Train consists of fl ying of the afternoon satellites Aqua, phase, Aqua will perform maneuvers to Aqua, PICASSO, CloudSat, PARASOL, PICASSO, CloudSat, PARASOL, and synchronize with the WRS, and could and Aura, with Aqua leading the train. Aura. The fi rst speaker in the group, normally synchronize with any WRS The nominal plan for the others is to Mark Schoeberl, the Aura Project Scien- path since it is the fi rst spacecraft in precess across the Aqua-MODIS scan- tist, began by noting that there is con- the afternoon constellation. However, ning path.

8 March/April 2001 • Vol. 13 No. 2

Wielicki explained that together, researchers will be able to obtain appro- enhances the science of both missions. PICASSO, CloudSat, and Aqua will priate subsets of Level 1 data from the allow studies of cloud feedbacks in the other missions. Stephens then presented some examples climate system in ways never before of CloudSat synergy with MODIS, possible. These studies would involve Stephens elaborated on how information CERES, and AMSR. He noted that processes in atmospheric state, cloud from one sensor can enhance the prod- MODIS optical depth provides indepen- physics, cloud optics, and top of atmo- ucts derived from others, with the pos- dent information that more tightly con- sphere, surface, and atmospheric radia- sibility of development of new products strains the relation between the power tive heating profi les. Additionally, for- and an opening of the possibilities for returned from radar and the water and mation fl ying will be useful for cloud addressing new science. ice content of the radar volume, thus validation with CloudSat and PICASSO. improving retrievals. Variables include cloud amount, cloud Stephens then spoke briefl y on the top height, cloud physical thickness, CloudSat mission, noting that it will Finally, Stephens stressed the impor- cloud base, cloud visible optical depth, include the fi rst 94 GHz spaceborne tance of coordinating CloudSat and cloud infrared spectral emissivity, cloud radar system. A unique feature is that Aqua validation efforts, noting also that liquid water path, cloud ice water path, the radar is extremely sensitive and has the need exists to establish a data fl ow cloud particle phase, and cloud particle a wide dynamic range. It sees the major- dialog and subsequent plan of action size. ity of clouds, from thin cirrus clouds among members of the constellation to deep convective clouds producing instrument teams. The A-Train will also facilitate aerosol heavy precipitation. The CloudSat sci- validation. The vertical locations of aero- ence objectives are to: Recompetition sol layers are critical for source region back-trajectories, and the locations of • measure the vertical structure of Following Stephens, Jack Kaye from cloud/aerosol in the same vertical layers clouds and quantify their ice and NASA Headquarters spoke on the plans are critical for indirect aerosol forcing. water content, in development for dealing with the MODIS can obtain good aerosol data upcoming expiration of science team over dark surfaces, but the A-Train will • predict clouds and precipitation, contracts. This will involve a separation allow us to obtain such data also over of the science efforts into two main cat- snow, ice, and all other surfaces. The • improve weather prediction and egories. First, the Core Instrument Team optimal scenario is to combine PICASSO clarify climatic processes, Activities, including algorithm mainte- with MODIS and PARASOL. Wielicki nance and key aspects of data product noted that precession across the MODIS • improve cloud information from validation, will be covered under an swath would help verify causes/physics other satellite systems (particularly appropriate, somewhat restricted solici- of angle dependent aerosol cloud prop- Aqua), tation. This will maintain the continuity erties from passive imagers providing and heritage to insure high quality data global climate data. • investigate the effects of aerosols on products for release to the broad science clouds and precipitation, and community. It is expected that support Next, Graeme Stephens of Colorado for these activities will decrease over State University presented on CloudSat • investigate the utility of the 94 GHz time as the processing algorithms sta- and the afternoon constellation. He reit- radar for observing precipitation in bilize and the initial validation studies erated that the combination of constella- the context of cloud properties from prove successful. Both Terra and Aqua tion observations well exceeds the sum space. instrument team activities will likely be of the individual parts and explained covered in one solicitation. that part of his purpose in speaking at Stephens then commented on two for- this meeting is to convince Aqua sci- mation-fl ying scenarios. The original Second, an NRA will be released to entists of the importance of CloudSat scenario involved CloudSat in formation solicit from the Earth sciences commu- contributions. The CloudSat team has with PICASSO-CENA (and more loosely nity long-term, multi-platform, multi- developed optimized retrieval methods with Aqua) to provide essentially instrument Science Data Analysis inves- that combine heterogeneous (multi-sen- instantaneous lidar/radar views of the tigations. Investigations will be sought sor) information derived from the con- atmosphere. The current scenario that address questions relating to dis- stellation. This, however, requires avail- involves CloudSat fl ying in a tight for- cipline areas and key science themes ability of the data. A critical issue thus mation with Aqua, aligning CloudSat rather than addressing single instru- becomes the exchange of data and how radar with nadir pixels of MODIS. The ment data sets. It is expected that quickly and at what cost the CloudSat combination of Aqua and CloudSat data support for these investigations will

9 THE EARTH OBSERVER

increase over time as the data products ing of the EOS production environment. • TDRSS is assumed to be available as from the EOS platforms reach appropri- scheduled. The Project has requested ate stages of maturity. Researchers will Barkstrom noted that the instrument nearly continuous coverage for the be allowed to use alternative algorithms teams have made considerable improve- fi rst three hours after launch and from those used in the standard prod- ments and effi ciencies to codes and algo- two 20-minute TDRSS contacts per ucts, although the funding here will not rithms. However, increased hardware orbit thereafter. be for new algorithm development. capacity is needed above the 1996 baseline to generate the higher-order geo- • Timeline is based on the nominal With these two types of solicitations, physical data products already commit- plan and does not account for con- the goal is to fund activities that carry ted for Terra and planned Aqua science. tingencies. the EOS project through transitions from Provisional cost estimates suggest that a pre-launch initial algorithm develop- much-desired three-fold increase in pro- • Scheduling of the MODIS roll ment, to post-launch algorithm refi ne- duction capacity at the DAACs and SIPS maneuver does not yet account for ment and stability, to initial validation could be obtained with a cost of approx- moon phase. studies, and fi nally to broader validation imately 7% of the annual ESDIS budget. studies and uses of the data products to • Instrument scheduling is based on Aqua Integrated Mission Timeline address and answer important scientifi c results of the last IMT review questions. The intention is to shift fund- as well as continuing information After Barkstrom, Fran Wasiak of the ing dollars more and more from algo- exchange with Instrument Opera- Aqua Instrument Planning Group pre- rithm development and maintenance to tions Teams and TRW, the Aqua sented an update on the Aqua Inte- scientifi c analysis. spacecraft developer. grated Mission Timeline (IMT). The third IMT review was held on October Data Processing Issues surrounding instrument com- 17, 2000, and was attended by repre- manding during the fi rst two weeks sentatives from the Aqua project, TRW, Following Kaye, Bruce Barkstrom, rep- include the fact that spacecraft and Instrument Operations Teams, and the resenting Chris Justice and the Science AMSR-E RunUp activities occupy most Flight Operations Team (FOT). The cur- Working Group on Data (SWGD), pre- of the fi rst two weeks. Teams still rent version of the IMT is based on sented on Terra and Aqua data process- have the option to schedule benign all the IMT reviews (March, July, and ing issues, beginning with an overview activities with their instruments during October 2000). Some adjustments in the of a workshop held on June 1-2, 2000, this period if they choose to do so, and Aqua maneuver plan are to move the at GSFC. The June 2000 workshop was MODIS may choose to perform transi- MODIS yaw maneuver from days 26-27 called to evaluate how well the EOS tion to the ON state earlier than day and 30-31 to days 32-33 and 37-38 and Data and Information System (EOSDIS) 15 now that AMSR-E RunUp has been add a CERES yaw maneuver on day 41. supports current and upcoming EOS shortened. One important maneuver that has not missions, to determine how require- changed is the deep-space pitch maneu- ments have changed, and to recommend It is the AIRS Team’s preference not ver scheduled for day 55. Plans call to solutions to meet evolving needs. to perform deep-space constant pitch baseline the IMT in March or April 2001. maneuvers, and the current IMT The participants at the June 2000 work- assumes no pitch maneuvers for the Assumptions guiding the IMT team shop discussed the then current oper- scheduling of AIRS activities, despite include: ating status of EOSDIS, in particular the planned pitch maneuver on day 55. the lower than expected throughput and • Activities, in general, are scheduled Under some scenarios, AIRS would not how it should be addressed. They noted to occur during the FOT prime shift. complete its activation checkout until that the February 1996 baseline sizing after the Launch-plus-90-days threshold. used to implement EOSDIS is not ade- • Per FOT direction, only one EOS Hence, AIRS has provided a preliminary quate to support current science data Polar Ground Network pass is used alternate plan of activities that needs to needs. Because that baseline was estab- per orbit. be implemented into the Baseline. lished before the algorithms were developed and could be run in the pro- • Instruments use only Alaska and The slip in the MODIS yaw maneuvers duction environment, it did not have a Svalbard ground stations. Spacecraft is primarily because the MODIS Team clear empirical basis. Terra instrument bus uses Alaska, Svalbard, and Wal- has elected to wait until day 15 to begin team representatives presented revised lops. McMurdo is not available for the outgassing procedure and prefers 14 system sizing estimates based on current use. days of outgassing rather than the ear- experience and improved understand- lier scheduled 11 days. MODIS activities

10 March/April 2001 • Vol. 13 No. 2

remain in the same order, slipping the fi rst set of yaw maneuvers to days 32-33. The second set of MODIS yaw maneuvers no longer needs to be delayed for MODIS Science Team Meeting CERES, and MODIS may opt to perform — Rebecca Lindsey ([email protected]), SSAI both sets of yaw maneuvers on four con- secutive days. MODIS SCIENCE TEAM MEETING, January 24 and 25, 2001 MODLAND Validation Workshop, January 22 and 23, 2001 The new review version of the IMT is MODIS Ocean Team Meeting, January 23 and 26, 2001 MODIS Characterization Support Team Meeting, January 23, 2001 to be released on March 30, while the MODIS Atmosphere Group Meeting, January 23, 2001 Baseline IMT is to be released two weeks MODIS Land Group Meeting, January 26, 2001 before Mission Rehearsal #1. Finally, the Product Development Tracking Tool has been proposed for IMT Change Request submittal. The MODIS Science Team Meeting and Outreach affi liated meetings convened in Colum- bia, MD, January 22-26, 2001. This arti- processing Steve Cole of the EOS Science News cle summarizes the activities of the systems are and Information Team at GSFC gave two-day plenary session on January 24 effi cient and that they are able to supply the last formal presentation of the day. and 25. Please see the “Meetings” sec- suffi cient power to process and repro- The EOS Science News and Information tion of the MODIS home page (http:/ cess data, determining how to support Team supports media outreach efforts /modis.gsfc.nasa.gov) for the complete MODIS Direct Readout users, and pre- of all EOS missions and researchers. meeting minutes for this meeting, as paring for Aqua. Cole noted that this is a critical time in well as other MODIS-related meetings the planning for media activities related for which minutes are available. Terra Status to the launch of Aqua. Input from the Vincent Salomonson, MODIS Science Aqua Science Working Group on the Team leader, began the meeting by Paul Ondrus gave a brief history of key stories that the media and public emphasizing the MODIS team’s com- Terra since launch. The high points should know about Aqua and its science mitment to aligning its efforts with are that all major systems are working needs to be given soon so it can be the Earth Science Enterprise’s research within specs, the craft is producing used to develop various media materi- strategy. He expressed his enthusiasm enough power, it is collecting all science als, including a “Science Writers’ Guide about the early results coming from the data, and it is satisfying pointing to Aqua.” team. MODIS’ major instrument systems requirements. The biggest challenge has work, the spectral bands are properly been managing the solid state recorder. Science Writers’ Guide topics should located, signal to noise ratios are good, Terra makes 4.8 TB of data each month; highlight key advantages of Aqua, and the gains appear to be stable. Data in one year, Terra has doubled the either from its new instruments or processing is stabilizing and products amount of Earth science data available from the usefulness of its data in are being produced and archived. The to the scientifi c community. Ondrus combination with other data, including calibration and characterization efforts reported that the deep space maneuver data from Terra. An initial list of pos- overcame several challenges this fi rst is still being negotiated with the Project sible Aqua research highlights was pre- year after launch. Many of the MODIS and the other instrument teams. sented. Topics included: improvements products have been released including in weather forecasting, sea-ice monitor- some Level 3 (L3) products from MODIS Status ing, snow-cover mapping and runoff every discipline group, and the team estimates, complete ocean color cover- is working toward improving product Bruce Guenther, MODIS Characteriza- age, diurnal cycles of clouds and solar quality through instrument character- tion Support Team Leader, gave a brief radiation, surface heat budget of the izations and validation. summary of instrument status, starting ocean, acceleration of the hydrological with the year’s highlights, among them cycle, insight into atmospheric water Salomonson concluded the talk with MODIS’ successful activation and com- processes, mapping wildfi re hazards, a summary of challenges that the mand operation. MODIS L1B data were and soil moisture content. Comments team would be addressing in the the fi rst Terra data to be publicly on this list and suggestions of specifi c future: reaching a stable instrument released; the solid-state recorder deliv- characterization state, ensuring data (Continued on page 17) ered 22.9 TB of data in 2000. The past

11 March/April 2001 • Vol. 13 No. 2

Validation investigations 1. additional sites with the same inves- 5. EDC DAAC’s MODIS Reprojection tigators; Tool: Both EOS Validation investigators and http://edc.usgs.gov/programs/sddm/ MODLAND PIs made presentations. 2. additional sites with additional modisdist/index.shtml There were also presentations from investigators (using protocols and MISR (Brugge), the Scientifi c Data pur- methods already developed); chase (Pagnuti), and NASDA’s GLI team (Honda). Presentations are available on- 3. network of sites with global repre- line (URL 1). Based on the presentations sentation; and and discussions from break-out sessions, (Continued from page 11) the meeting arrived at several conclu- 4. integration with end user feedback. Minutes of the Aqua Science sions. In general, there is no set defi ni- Working Group Meeting Summary tion for what it means for a product to be “validated.” That is, validation activities are incremental, with incremental Validation campaigns have been under- researchers active in these areas were stages including: taken for each of the MODLAND requested of all meeting attendees. products. They represent a signifi cant • exploring products at a few well- amount of work and dedicated Lastly, Parkinson led a brief discussion instrumented sites; resources. Results are starting to come on whether to attempt to produce a spe- in. Validation activities in 2001 will ben- cial Aqua issue of a professional journal. • incorporating multiple sites with efi t from stable MODIS data. As activi- Salomonson commented that the Terra similar measurements; ties continue, emphasis will be placed special issue of the IEEE Transactions on standardizing measurement tech- on Geoscience and Remote Sensing was • developing a globally representative niques through protocols. MODLAND useful and a corresponding issue could network and incremental goals; will continue to focus on the EOS Land be equally useful for Aqua. One sug- Validation Core Sites and to interact gestion was to emphasize AIRS/AMSU- • checking and refi ning products to be with international partners through the A/HSB and AMSR-E, with briefer dis- on target – “unbiased”; CEOS, WGCV-LPV. cussions regarding MODIS and CERES, both of which are included in the IEEE • estimating product uncertainty at Acknowledgments pilot sites; special issue on Terra. It was decided that a special Aqua issue should be pur- • comparing initial results with theo- Thanks to Nazmi El Saleous, Robert sued. retical error bars; Wolfe and David Roy for their MODIS production and QA input at the meeting The date for the next meeting of the • estimating product uncertainty with and Rebecca Lindsey for help in prepar- Aqua Science Working Group was set global representation, and ing this report. for Thursday, August 2, 2001 at GSFC.

• inferring the impact of uncertainty Related URLs: on products’ use. 1. MODIS Land Team Validation Annual Review Meeting, 2000: The ultimate driver should be the utility http://modis-land.gsfc.nasa.gov/ of products for addressing science and val/modland_val_mtg_2001.html application questions. Current activities are addressing the early stages in this 2. CEOS Working Group on Cal/Val – incremental structure. Land Product Validation subgroup: http://modis-land.gsfc.nasa.gov/ From the experience gained during the val/modland_val_mtg_2001.html ﬁ rst year of MODIS data collection, there is a clear need for a close 3. MODLAND Production coupling between external validation http://modland.nascom.nasa.gov/ investigators and the science team. This prod/ interaction between several investiga- 4. MODLAND Science Quality Flag tors and the science team could provide http://modland.nascom.nasa.gov/ expanded opportunities for validation QA_WWW/release.html activities including: