Global Change Master Directory (GCMD)

Data Sets

Services / Tools

Ancillary Descriptions

Are you using a browser that doesn't support JavaScript or have you disabled JavaScript?

If you have disabled JavaScript, you must re-enable JavaScript to use this page.
Or you can view this record using the Text Only Format.

TRMM Microwave Imager (TMI) Gridded Oceanic Rainfall Product (TRMM Product 3A11)

Entry ID: GES_DISC_TRMM_TMI_3A11_V6

[ Get Data ]
[ Update this Record ]

Summary

Abstract: The Tropical Rainfall Measuring Mission (TRMM) is a joint U.S.-Japan satellite mission to monitor tropical and subtropical precipitation and to estimate its associated latent heating. TRMM was successfully launched on November 27, at 4:27 PM (EST) from the Tanegashima Space Center in Japan.

The TRMM Microwave Imager (TMI) is a nine-channel passive microwave radiometer, which builds on the ... heritage of the Special Sensor Microwave/Imager (SSM/I) instrument flown aboard the Defense Meteorological Satellite Program (DMSP) platforms. Microwave radiation is emitted by the Earth's surface and by water droplets within clouds. However, when layers of large ice particles are present in upper cloud regions - a condition highly correlated with heavy rainfall - microwave radiation tends to scatter at frequencies above 19 GHz. The TMI detects radiation at five frequencies chosen to discriminate among these processes, thus revealing the likelihood of rainfall. The key to accurate retrieval of rainfall rates by this method is the deduction of cloud precipitation consistent with the radiation measurement at each frequency. The TMI frequencies are 10.65, 19.35, 37 and 85.5 GHz (dual polarization), and 21 GHz (vertical polarization only).

The TMI Gridded Oceanic Rainfall Product, also known as TMI Emission, consists of 5 degree by 5 degree monthly oceanic rainfall maps using TMI Level 1 data as input. Statistics of the monthly rainfall, including number of samples, standard deviation, goodness-of-fit (of the brightness temperature histogram to the lognormal rainfall distribution function) and rainfall probability are also included in the output for each grid box. Spatial coverage is between 40 degrees North and 40 degrees South owing to the 35 degree inclination of the TRMM satellite.

TMI brightness temperature histograms at 1 degree intervals are generated based on the 19, 21 and 19-21 GHz combination channels obtained from the Level 1B (calibrated brightness temperature) TMI product. Monthly rainfall indices over the ocean are derived by statistically matching monthly histograms of brightness temperatures with model calculated rainfall Probability Distribution Functions (PDF) using the 19-21 GHz combination data. Retrieved monthly rainfall data must pass a quality test based on the quality of the PDF fit.

The data are stored in the Hierarchical Data Format (HDF), which includes both core and product specific metadata applicable to the TMI measurements. A file contains 12 arrays of rainfall data and supporting information each of dimension 72 x 16, with a file size of about 40 KB (uncompressed). The HDF-EOS "grid" structure is used to accommodate the actual geophysical data arrays. There is 1 file of TMI 3A11 data produced per month.

Description: OPeNDAP Earth Science Data TRMM 3A11, TRMM Microwave

Multimedia Sample

View full image

Caption: 3A11 TMI oceanic monthly accumulated surface rainfall, 2005/11/01-2005/12/01

Description: Sample image for TRMM data product 3A11, TMI oceanic monthly accumulated
surface rainfall, 2005/11/01-2005/12/01

Geographic Coverage

(Click for Interactive Map)

Spatial coordinates

N: 40.0

S: -40.0

E: 180.0

W: -180.0

Data Set Citation

Dataset Originator/Creator: NASA,JAXA, Tropical Rainfall Measuring Mission (TRMM)

Dataset Title: TRMM Microwave Imager (TMI) Gridded Oceanic Rainfall Product (TRMM Product 3A11)

Version: 6

Online Resource: http://mirador.gsfc.nasa.gov/cgi-bin/mirador/presentNavigation.pl?t...

Temporal Coverage

Start Date: 1997-12-01

Location Keywords

GEOGRAPHIC REGION > TROPICS

Data Resolution

Latitude Resolution: 5 degrees
Longitude Resolution: 5 degrees
Horizontal Resolution Range: 500 km - < 1000 km or approximately 5 degrees - < 10 degrees
Vertical Resolution: Surface
Temporal Resolution: Monthly
Temporal Resolution Range: Monthly - < Annual

Science Keywords

ATMOSPHERE > PRECIPITATION > PRECIPITATION AMOUNT

ATMOSPHERE > PRECIPITATION > PRECIPITATION RATE > CONDITIONAL RAIN RATE

ATMOSPHERE > PRECIPITATION > RAIN > RAIN PROBABILITY

SPECTRAL/ENGINEERING > MICROWAVE > BRIGHTNESS TEMPERATURE > 2.0 * TB(19V) - TB(21V)

ISO Topic Category

CLIMATOLOGY/METEOROLOGY/ATMOSPHERE

IMAGERY/BASE MAPS/EARTH COVER

Platform

TRMM > Tropical Rainfall Measuring Mission

Instrument

TMI > TRMM Microwave Imager

Project

EOS > Earth Observing System

EOSDIS > Earth Observing System Data Information System

ESIP > Earth Science Information Partners Program

TRMM > Tropical Rainfall Measuring Mission Project

Quality Quality arrays have been set aside in the files to be populated in the future, once the characteristics of the sensor become better understood and enhancements are made to the science algorithms. Quality indicators will be available for each 5 degree gridbox in the monthly rainfall map.

Access Constraints None

Ancillary Keywords

FREEZING HEIGHT

LOGNORMAL RAINFALL PROBABILITY DISTRIBUTION FUNCTION

Data Set Progress

IN WORK

Originating Center

GSFC_DAAC

Data Center

Goddard Earth Sciences Data and Information Services Center (formerly Goddard DAAC), Global Change Data Center, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA

Data Center URL: http://disc.gsfc.nasa.gov/

Data Center Personnel
Name: GES DISC HELP DESK SUPPORT GROUP Phone: 301-614-5224 Fax: 301-614-5268 Email: gsfc-help-disc at lists.nasa.gov Contact Address: Goddard Earth Sciences Data and Information Services Center Code 610.2 NASA Goddard Space Flight Center City: Greenbelt Province or State: MD Postal Code: 20771 Country: USA

Distribution

Distribution Media: FTP

Distribution Size: increasing monthly

Distribution Format: HDF

Fees: none

Personnel

LONG S. CHIU

Role: INVESTIGATOR

Email: lchiu at gmu.edu

Contact Address:

Building ST-1 Room 211

George Mason University

City: Fairfax 22030-4444

Province or State: VA

Postal Code: 22030-4444

Country: USA

HYDROLOGY DATA SUPPORT TEAM

Role: TECHNICAL CONTACT

Phone: (301) 614-5165

Fax: (301) 614-5268

Email: gsfc-help-disc at lists.nasa.gov

Contact Address:

Hydrology Data Support Team, Code 610.2

Goddard Space Flight Center

City: Greenbelt

Province or State: MD

Postal Code: 20771

Country: USA

Publications/References

Wilheit, T.T., A.T.C Chang and L.S. Chiu, 1991: Retrieval of Monthly Rainfall Indices from Microwave Radiometric Measurements Using Probability Distribution Functions. J. Atmos. Oceanic Tech., 8, 118-136.

Interface Control Specification Between the Tropical Rainfall Measuring Mission Science Data and Information System (TSDIS) and the TSDIS Science User (TSU). Volume 4: File Specifications for TSDIS Products-Level 2 and Level 3. NASA Goddard Space Flight Center, March 5, 1999.

Creation and Review Dates

DIF Creation Date: 2006-05-25

Last DIF Revision Date: 2012-01-03

Reformat as FGDC document

View Text Only Format

[ Update this Record ]