Tropical Rainfall Measuring Mission (TRMM)

Tropical Rainfall Measuring Mission (TRMM)
Science Objective: Advance knowledge of
global water and energy cycles through
observed time and space distributions of
tropical rainfall, hydrometeor structure and
latent heating.
9-year TRMM rain climatology
Approach: Accurate estimation of precipitation
characteristics through first-time use of passive
and active microwave instruments.
10 years of data!
Joint NASA/JAXA mission launched in Nov.
1997 into inclined (35º) ) orbit (400 km)
Instrument Payload:
TRMM Microwave Imager (TMI)
10, 19, 37, 86 GHz, conical scanning
Precipitation Radar (PR) [Japan]
14 GHz, cross-track scanning
Lightning Imaging Sensor (LIS) [MSFC]
Staring optical array
Visible IR Scanner (VIRS)
5-channel, cross-track scanning
3-hr multi-satellite rain analysis in real-time
Vertical structure from radar
1

TRMM Mission Overview
• TRMM launched in Nov. 1997 from Japan, orbit boosted from 350 to 402 km
in Aug. 2001; 6+ years at 402 km, 3+ years at 350 km
• TRMM started as an experimental mission, but has become the primary
satellite in a global set of satellites to observe and study precipitation
characteristics and variations
• TRMM satellite data products (both research and real-time) produced by
TSDIS [includes multi-instrument and multi-satellite products-from beginning
of mission].
• Spacecraft status: all spacecraft systems in excellent shape for continuation;
one of two solar arrays is parked in horizontal position to avoid SADA failure.
• Instrument status: Precipitation Radar (PR)--no moving parts, electrically
scanning--no component limiting life; TRMM Microwave Imager (TMI)--has
DoD instrument heritage with 10+ yr median lifetime; Visible and IR Scanner
(VIRS)--very minor response degradation; Lightning Imaging Sensor (LIS)--
no moving parts, no component limiting life
2

TRMM Lifetime Prediction
PVT Actual Propellant Remaining No August 2001 Boost March 2007 PlusEarly March 2007 MeanNom
600
Propellant Remaining (Kg)
500
400
300
200
Initial fuel: 800+ kg
Orbit raised from
350 km. to 402 km.
Station-keeping fuel sufficient to reach 2012-2013
based on current solar flux forecasts
TRMM fuel currently at 119 kg
100
No Boost
Early solar cycle phase, high solar flux
Nominal
0
Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Jan-10 Jan-11 Jan-12 Jan-13 Jan-
Date (Mon-YY)
3

Major Science Results
Nearly 850 journal articles using TRMM data
• Space standard for measuring precipitation
• Improved climatology of tropical rainfall and variations
• Vertical hydrometeor/heating structure and diurnal signal
• Improved climate and weather modeling
• Impact of humans on precipitation
• Hurricane/typhoon structure/evolution
• Multi-satellite (~3-hr) rainfall analyses using TRMM+other satellites
• Flood and agricultural applications
• Operational use of data by weather
agencies.
Number of TRMM papers
Cumulative
Yearly total
4

TRMM Senior
Tropical Rainfall Measuring Mission
TRMM
Senior Review Proposal
2007
Review
• Mission reviewed every 2
years
• TRMM Viewed as central
to NASA Strategic Plan
and Earth Science
Objectives
• Ranked as having very
high utility for operational
agencies
5

TRMM Basic Mission Extension:
Data Products
• Successful extension means continuation of TRMM Standard and real-time
level 1, 2, 3 products (currently Version 6)
• As part of overall Precipitation Measurement Mission (PMM) program
improved Version 7 products will start in FY08-09. Version 7 is next step
toward GPM products [TSDIS transitioning into Precipitation Processing
System (PPS) for PMM (TRMM/GPM)].
• Multi-instrument and multi-satellite products have been produced from day-1
of TRMM. Current multi-satellite processing in TSDIS involves information
from from eight microwave-instrumented satellites, plus geosynchronous IR
information, plus raingauge information. Experience now is risk reduction for
GPM.
• Real-time TRMM single instrument and multi-satellite products extensively
used by NOAA, DoD, Japan, Europe and international agencies
6

Science with an Extended TRMM Mission
Overall Science Objective: Determine the time and space varying characteristics of
tropical rainfall, hydrometeor structure, and associated latent heating and how these
characteristics are related to variations in the global water and energy cycles
Extended TRMM Mission will provide:
• An improved climatology of precipitation characteristics, especially extremes
• Improved diagnosis and closure of global (and regional) water cycles
• Diagnosis and testing of inter-decadal and trend-related processes in the water cycle
• Assessment of impact of humans (e.g., cities, deforestation, and aerosols) on rainfall
characteristics and processes
• Robust determination of convective system, tropical cyclone and lightning characteristics
• Advances in hydrological applications over land on basin and continental scales
• Improved modeling of global water/energy cycles for weather/climate predictions
• Improved monitoring and forecasting of tropical cyclones, floods and other hazardous
weather
Extension of TRMM will take advantage of unique opportunity to obtain
combined active and passive observations of clouds, aerosols, and
precipitation with “A-Train”--Cloudsat, CALIPSO, Aqua--and TRMM
7

Science With Multiple Satellites: Does the
Saharan Air Layer Have a Negative Influence
on Hurricanes
Some storms are surrounded by Saharan air and yet
intensify to Category 4 or 5 intensity.
Image: Hurricane Fabian (2003) surrounded by dry,
dusty air. Data from TRMM 3B42, MODIS, and AIRS.
Dust 24-h Accumulated Rain Relative Humidity 24-h Accumulated Rain
8

Overview of Enhanced Mission
TRMM enhanced mission is very modest addition to basic mission continuation
involving additional product generation and implementation of four products
• Precipitation Feature (PF) database--involves adaptation as standard
product of highly-used team member algorithm/product for wider
distribution--allows for identification of characteristics of precipitation
features (areas, etc.) rather than pixel information
• Wide-swath primary precipitation product--improved multi-instrument
product covering full swath and providing a TRMM-best instantaneous
surface rain estimate
• A-Train Subset of TRMM data--subsets of TRMM data matched with
cross-overs with A-Train within various time offsets
• Tropical cyclone accumulation rain maps using TRMM multi-satellite
product and cyclone track information
9

TRMM Data Used for Hurricane/Typhoon Monitoring
TRMM TMI data used by NOAA and DoD (and int’l
agencies) for tropical cyclone detection, location
and intensity estimation--600 TRMM-based tropical
cyclone “fixes” in 2004
TRMM orbit advantageous for tropical cyclone
monitoring--it is always in tropics, sampling best in
10-35º latitude storm band. TMI resolution twice as
good as operational sensors, about same as AMSR.
Precessing orbit provides off-time observations
relative to sun-synchronous microwave
observations.
Hurricane Katrina
TRMM image from
NRL Tropical
Cyclone web site
from TRMM web site
TRMM radar (PR) crosssections
of hurricanes
available in real-time for
operational analysis from
TRMM web site
10

TRMM Detects Heavy Rainfall in Dominican
Republic from Tropical Storm Noel
• TRMM Multi-satellite
precipitation analysis measures
>400 mm of rain over D. R.
and Haiti from Noel
• 81 deaths, several hundred
thousand displaced
“Your images have been
incredible--they are stunning and
extremely useful. It was even
presented to the minister of
environment and head of disasters
in the DR. Deeply appreciated.
Please know we are crediting you
everywhere.” – Daniel Irwin, MSFC,
SERVIR Project Manager
11
Images by Hal Pierce, NASA/GSFC

http://trmm.gsfc.nasa.gov
12

TRMM Tracks Tropical Cyclone Rainfall
• Rainfall accumulation maps
available on TRMM web page:
http://trmm.gsfc.nasa.gov
• ATL and EPAC available June-
Oct 1998-2006
• WPAC available June-Oct 1998-
2005
• N. Indian Ocean available June-
Oct 1998-2004
• Combined with other satellites, the
TRMM multi-satellite precipitation
analysis (3B42) helps map rainfall
evolution in hurricanes.
Hurricane Isabel
accumulated
rainfall
13

http://trmm.gsfc.nasa.gov
14

3 rd International TRMM Science
Conference
February 4-8, 2007
Las Vegas, NV
202 Abstracts submitted
15