Tropical Rainfall Measuring Mission TRMM

1
Tropical Rainfall Measuring Mission (TRMM) TRMM
Multi-Satellite Real-Time Precipitation Estimates
(3-hr interval)
Near global merged precipitation estimates
using TRMM, polar-orbit microwave, and
geosynchronous-IR data (NOAA/CPC merged IR
product) Bias removal relative to TRMM via
histogram matching (30 day trailing
window) 3-hr, 50N-S 0.25x0.25 lat./long.
grid available 4-hr after real time (available
via ftp see U.S. TRMM web sitetrmm.gsfc.nasa.gov
)
2
TRMM Multi-Satellite Real-Time Precipitation
Estimates
3B40RT Combined microwave (TRMM and
TRMM-calibrated SSM/I)
3B41RT Microwave-calibrated geo-IR
estimate (Geo-IR from NOAA/CPC)
3B42RT Merged microwave and geo-IR estimates
Adler/Huffman
3
TRMM Data Used by USAID, USGS for Crop Forecasts
USAID Famine Early Warning System Network
(USAID/FEWS-Net) is a joint program of DoS, USGS,
NOAA Goal is crop and weather assessment around
the world
TRMM real-time Multi-Satellite Precipitation
Analysis (MPA) tested in 2003 first results are
promising MPA now in quasi-operational use in
Central America, Africa, and Asia
4
Heavy Rains/Flooding in Dominican Republic
Peak total for 24 hour about 430 mm
5
Example Day of Validation over Australia Beth
Ebert (BMRC-Australia)
6
Limitations of TRMM-based Multi-satellite
Precipitation Analysis (MPA)

• Biases related to satellite retrievals (over
  land) -Solution improved retrievals, use of
  TRMM PR data, calibration by gauges
• False precipitation signals due to cold and/or
  wet ground mainly in middle/high latitudes cool
  season -Solution improved retrievals, better
  screening, use of high frequency PMW, use of
  TOVS/AIRS data, eventual use of GPM radars for
  calibration
• Underestimation of shallow, orographic
  precipitation -Solution Use of TRMM (and
  eventually GPM) radar for calibration of
  passive techniques
• Limitations of IR-based rain estimation -Solution
  more microwave via GPM constellation, others

7
Plans for TRMM-based Multi-Satellite, 3-hr
Analysis

• Real-time analysis will incorporate PR
  information as calibrator
• Non real-time analysis (TRMM product 3B-42) will
  become 3-hr in in Version 6, from Jan. 1, 1998
• AMSR, AMSU data will be added in both standard
  (research) and real-time product
• Real-time product will use monthly gauges
  (previous months/years) to improve bias (if
  necessary)
• An improved geo-IR technique (e.g., Convective
  Stratiform Technique CST) may be implemented if
  tests indicate improvement
• Working on extension to high latitudes using
  AMSU, TOVS and AIRS
• Improved techniques for merging/blending
• TRMM V6 3B-42/43 may be a tool to improve GPCP
  global products (include TRMM, go to 3 hr, and
  use TRMM to calibrate 25 year data set

8
AMSR and AMSU Data Will Improve the TRMM MPA
Current combined microwave data coverage
Averages 44 with F13, F14, F15, and
TRMM Coverage with AMSR-E Adds
11 Coverage with AMSR-E and all 3 AMSU-B
Adds 33