1. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 1

2. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 2 1. HQ Level 1 Science Requirements high level document -- Jun/2001 time frame 2. GPM Science Implementation Plan detailed document -- Aug/2001 1 st iteration Feb/2002 2 nd iteration 9 study groups at work 1. climate diagnostic 2. weather-climate prediction & data assimilation 3. radiometer synthesis (deployment & retrieval) 4. radar synthesis (retrieval & combined algorithms) 5. validation requirements & supporting field campaigns 6. GWC, hydrometeorology, land surface processes, carbon budget 7. marine boundary layer & ocean fluxes 8. cloud-radiation modeling and cloud microphysics 9. outreach

3. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 3 Uncertainty in global tropical rainfall estimates has been reduced from 50% to 25% using TRMM data GPM’s Key Science Theme Global Water & Energy Cycle GOAL: Observe, understand, & model Earth system to learn how it is changing, & consequences for life on Earth. SOLUTION: Establish existence (or absence) of trend in rate of global water cycle -- acceleration would lead to faster evaporation, increased global average precipitation, & general increase in extremes, particularly droughts & floods. GPM will extend TRMM’s observations of rainfall rates to higher latitudes thus yielding more complete and accurate representation of global water cycle. Advanced rainfall measurement core satellite will make detailed & accurate estimates of precipitation structure & microphysical properties -- while constellation of drone satellites flying passive microwave radiometers will provide required temporal sampling of highly variable precipitation systems.

4. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 4 Climate Feedback Impacts Earth System Response NASA ESE Strategy for Earth System Science Forces Acting on Earth System How is Earth changing & what are consequences for life on Earth ? 1. How is global Earth system changing ? 2. What are primary causes of change of Earth system ? 3. How does Earth system respond to natural & human-induced changes ? 4. What are consequences of change in Earth system for human civilization ? 5. How well can future changes in Earth system be predicted ?

5. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 5

6. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 6 Atmosphere WaterLand Weather, Climate, & Hydrology (1) Climate Diagnostics: refining & extending precipitation climatologies including snow climatologies; detecting statistically significant global & regional precipitation trends (2) Global Water & Energy Cycle / Hydrological Predictability: global water & energy cycle (GWEC) analysis & modeling; water transports; water budget closure; hydrometeorological modeling; fresh water resources prediction (3) Climate Change / Climate Predictability: climate- water-radiation states; climate-change analysis & prediction; GWEC response to climate change & feedback; (4) Data Assimilation / Weather & Storms Predictability: rainfall data assimilation; global-regional scale NWP techniques (5) MBL Processes: air-sea interface processes & surface flux modeling; ocean mixed layer salinity changes (6) Land Processes: land-atmosphere interface processes & surface flux modeling; integrated surface radiation-energy-water- carbon budget process modeling (7) Coupled Cloud-Radiation Models: diagnosis of cloud dynamics, macrophysical/microphysical processes, & response of 3D radiation field; parameterizing microphysics & radiative transfer in nonhydrostatic mesoscale cloud resolving models (8) Retrieval/Validation/Synthesis: physical retrieval of precipitation & latent heating; algorithm calibration & products normalization; algorithm validation & quantification of uncertainty; synthesis of validation for algorithm improvement (9) Applications/Outreach: weather forecasting; flash flood forecasting; news media products; educational tools GPM’s Nine (9) Science Discipline Areas

7. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 7 GPM Reference Concept Core Satellite TRMM-Like S/C, NASA H2A Launch, NASDA Non-Sun Synchronous Orbit ~ 65° Inclination ~450 km Altitude Dual Frequency Radar, NASDA Ku & Ka Bands ~ 4 km Horizontal Resolution ~250 m Vertical Resolution Multifrequency Radiometer, NASA 10.7, 19, 22, 37, 85 GHz V&H Pol Constellation Satellites Dedicated Small or Pre-existing Experimental & Operational Satellites with PMW Radiometers Revisit Time 3-Hour goal Sun-Synchronous Polar Orbits ~600 km Altitude OBJECTIVE: Understand Horizontal & Vertical Structure of Rainfall & Its Microphysical Nature. Train & Calibrate Algorithms for Constellation Radiometers. OBJECTIVE: Provide Sufficient Sampling to Reduce Uncertainty in Short-term Rainfall Accumulations. Extend Scientific and Societal Applications. Global Precipitation Processing Center Produces Global Precipitation Data Product Streams Defined by GPM Partners Precipitation Validation Sites Selected & Globally Distributed Ground- Based Supersites (polarimetric radar, radiometer, raingages, & disdrometers) & Dense Regional Raingage Networks

8. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 8 TRMM 1-day coverage

9. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 9 Near Term Satellite Data Streams for TRMM/EOS Eras from Passive Microwave Radiometers & Precipitation Radars [at left are actual (bold) nodal crossing times (DN) or non-sun-synch labels ] CY 86-05 86 879899000102 03 0405 90 959697888994919293 0530 DN 0130 DN 0830 DN SSM/I SSMIS SSM/I SSMIS MSU  AMSU-A PR/TMI TRMM (35 ∞  inc) AMSR-E DMSP F10 DMSP F8 EOS AQUA DMSP F16 DMSP F17 F11 F12 F13F14 F15 NSS ADEOS II 1030 DN AMSR-J NOAA-JNOAA-L NOAA-N NOAA-DNOAA-KNOAA-M MSU  AMSU-A 0730 DN Potential Gap KEY carries preferred PMW frequencies carries alternate PMW frequencies  INSTRUMENTS 0830 DN  Continuous Geosynchronous Satellite Coverage by GOES E/W, METEOSAT, & GMS 

10. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 10 Projected Satellite Data Streams for GPM Era from Passive Microwave Radiometers & Precipitation Radars [at left are either actual (bold) or orthodox (paren) nodal crossing times (DN or AN) or non-sun-synch labels ] CY 99-18 99001112131415161718 03 080910010207040506 AMSR-J F20 NPOESS C1 F18 SSM/I SSMIS CMIS SSM/I SSMIS CMIS MSU  AMSU-A AMSR-E N-CMR GCOM-B1 GPM Core (65 ∞ inc) EOS AQUA PR/TMI DPR/ATMI TRMM (35 ∞  inc) DMSP F14 DMSP F16 NPOESS C3 DMSP F15 DMSP F17F19 NPOESS LITE-CMIS ADEOS II Euro-GPM II Euro-GPM I NASA-GPM I MEGHA-TROPIQUES (20 ∞  inc) MADRAS Partner-GPM II Partner-GPM I E-CMR P-CMR I P-CMR II FY-3 TBD 0530 DN 0830 DN 1030 DN NSS 0130 DN TBD NOAA-MNOAA-K CMIS MSU  AMSU-A 0730 DN NOAA-LNOAA-N Potential Gap KEY carries preferred PMW frequencies carries alternate PMW frequencies NOAA-J (0230 DN ) (1430 AN ) (1730 AN ) (2030 AN ) (2330 AN ) (1030 DN + ?15?) NPOESS C2 NOAA-N ’  Continuous Geosynchronous Satellite Coverage by GOES E/W, METEOSAT/MSG, & GMS  (0830 DN ) (0530 DN ) NPP-ATMS TBD Replacement Era

11. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 11 TRMM Era Constellation Coverage 3-hour sensor ground trace TRMM + DMSP(F14) + DMSP(F15)

12. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 12 EOS Era Constellation Coverage 3-hour sensor ground trace TRMM + DMSP(F15) + DMSP(F16) + AQUA + ADEOS II

13. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 13 GPM Systematic Measurement Coverage (Core + 6 constellation members) 3-hour sensor ground trace GPM Core + MEGHA-TROP + DMSP(F18) + DMSP(F19) + GCOM-B1 + NASA-GPM I + Euro-GPM I & II + Partner-GPM I & II

14. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 14 Winter 1997/98 (warm SSTs) Winter 1998/99 (cool SSTs) Winter 1999/00 (cool SSTs) TRMM Precipitation Radar (PR) Rainfall Intensity Histograms for Tropical Oceans Number of Counts Precipitation Intensity Category Precip Intensity (mm/h) (F.R. Robertson, GHCC)

15. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 15 TRMM-retrieved Radar & Radiometer Rainfall Anomaly Time Series with MSU-retrieved ice index (DCI) ( anomalies normalized by annual mean ) (F.R. Robertson; GHCC)

16. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 16 State of Art Climate Model Next Generation Climate Model Precipitation Prediction: Key Objective of Water Cycle Research NOW GOAL

17. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 17 GPM Validation Strategy Tropical Continental Confidence sanity checks GPM Satellite Data Streams Continuous Synthesis ∑ error variances ∑ precip trends Calibration Mid-Lat Continental Tropical Oceanic Extratropical Baroclinic High Latitude Snow Research Quality Data Algorithm Improvements Research ∑ cloud macrophysics ∑ cloud microphysics ∑ cloud-radiation modeling FC Data Supersite Products II. GPM Supersites  Basic Rainfall Validation hi-lo res guage/disdrometer networks polarametric Radar system  Accurate Physical Validation scientists & technicians staff data acquisition & computer facility meteorological sensor system upfacing multifreq radiometer system D o /DSD variability/vertical structure convective/stratiform partitioning III. GPM Field Campaigns  GPM Supersites cloud/ precip/radiation/dynamics processes  GPM Alg Problem/Bias Regions targeted to specific problems I. Basic Rainfall Validation  ∑  Raingauges/Radars new/existing gauge networks new/existing radar networks

18. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 18 Focused Field Campaigns Meteorology-Microphysics Aircraft GPM Core Satellite Radar/Radiometer Prototype Instruments Piloted UAVs 150 km Retrieval Error Synthesis Algorithm Improvement Guidance Validation Research Triple Gage Site (3 economy scientific gages) Single Disdrometer/ Triple Gage Site (1 high quality-Large Aperature/ 2 economy scientific gages) 150 km 100-Site Lo-Res Domain Centered on Pol-Radar 5 km 100-Site Hi-Res Domain Center-Displaced with Uplooking Radiometer/Radar System [10.7,19,22,35,85,157 GHz/14,35,95 GHz] Data Acquisition- Analysis Facility DELIVERY Legend Polarametric Radar Uplooking Radiometer/Radar Meteorological Tower Supersite Template Site Scientist (3) Technician (3)

19. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 19 Supersite Products & Customers 1. Regional Bias Uncertainties (synthesis/continuous) : ∑ climate trend detection specialists 2. Regional Error Variances (synthesis/continuous) : ∑ weather/hydrology forecast specialists ∑ model data assimilation specialists ∑ rain data user specialists 3. Algorithm Calibration (synthesis/continuous) : ∑ satellite algorithm specialists 4. Rain GV Products (datasets/delayed) : ∑ rain data validation researchers

20. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 20 Where can NASA & NASDA Find Common Ground on GPM Mission Objectives? 1. better measurement is achievable -- DPR & ATMI together produce reference & calibration algorithm because of sensitivity to DSD 2. extended (global coverage) addresses global water cycle & enables measurement of snow 3. increased temporal sampling brings in additional science disciplines 4. 4-dimensional precipitation structure & macro/micro physics of clouds can be fully explored 5. use TRMM mini-constellation as launch pad to GPM era constellation

21. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 21

22. GPM GPM Science Requirements: Eric A. Smith May 15, 2001 22