Daily TRMM and Others Rainfall Estimate (3B42 V7 derived) V7

Metadata Updated: December 18, 2017

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 precipitation-relevant instruments on the TRMM satellite include the Precipitation Radar (PR), an electronically scanning radar operating at 13.8 GHz; TRMM Microwave Image (TMI), a nine-channel passive microwave radiometer; and Visible and Infrared Scanner (VIRS), a five-channel visible/infrared radiometer.

The purpose of the 3B42 algorithm is to produce TRMM- and raingauge-adjusted multi-satellite precipitation rate (in mm/hr) and root-mean-square (RMS) precipitation-error estimates. The algorithm combines multiple independent precipitation estimates from the TMI, Advanced Microwave Scanning Radiometer for Earth Observing Systems (AMSR-E), Special Sensor Microwave Imager (SSMI), Special Sensor Microwave Imager/Sounder (SSMIS), Advanced Microwave Sounding Unit (AMSU), Microwave Humidity Sounder (MHS), and microwave-adjusted merged geo-infrared (IR). All input microwave data are intercalibrated to TRMM Combined Instrument (TCI) precipitation estimates (TRMM product 3B31); the IR estimates are computed using monthly matched microwave-IR histogram matching; then missing data in individual 3-hourly merged-microwave fields are filled with the IR estimates. After the preprocessing is complete, the 3-hourly multi-satellite fields are summed for the month and combined with the monthly accumulated Global Precipitation Climatology Centre (GPCC) rain gauge analysis using inverse-error-variance weighting to form a monthly best-estimate precipitation rate, which is TRMM Product 3B43. The final step is to scale all the 3-hourly estimates for the month to sum to the monthly value (for each gridbox separately). The final 3B42 precipitation (in mm/hr) estimates have a 3-hourly temporal resolution and a 0.25�x0.25� spatial resolution. The spatial coverage is the latitude band 50�S to 50�N.

Important Changes: After the initial Version 7 processing, it was discovered that AMSU data were neglected in the first retrospective processing of both the Version 7 TMPA (3B42/43) and TMPA-RT (3B40/41/42RT) data series, which created an important shortcoming in the inventory of microwave precipitation estimates used during 2000-2010. In addition, a coding error in the TMPA-RT replaced the occasional missings in product 3B42RT with zeros. Accordingly, both product series were retrospectively processed again. The main impact in both series was to improve the fine-scale patterns of precipitation during 2000-2010 (and for 3B4xRT into late 2012). Averages over progressively larger time/space scales should be progressively less affected. [This is the reason the lack of AMSU went undiscovered; the merger system copes very reasonably with missing data.] Nonetheless, users are urged to switch to the newest Version 7 data sets. The newest runs may be identified by the file names: V.7 3B42/43 suffix of "7A.HDF" for January 2000 - September 2010 V.7 3B4xRT suffix of "7R2.bin" for 1 March 2000 - 6 November 2012 It continues to be the case that the Version 7 3B42/43 is some 4% higher than the calibrating data set (2B31) over oceans, which is still under study. However, the initial conclusion is that it results from the sampling mismatch between the (very sparse) TCI and the (much denser) microwave constellation. At the large scales this offset seems to be nearly a proportional constant.

TMPA Restarted with October 2014: On October 07, 2014, routine production ended for the TRMM PR precipitation estimates. Since PR is no longer available, the TMI/PR combined instrument (TCI) estimates are also no longer available. As products 3B42/3B43 use the TCI estimates as the satellite calibrator, September 2014 is the last month these products were produced in this way. In a...

Access & Use Information

Public: This dataset is intended for public access and use. License: U.S. Government Work
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Dates

Metadata Created Date October 8, 2014
Metadata Updated Date December 18, 2017
Data Update Frequency irregular

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date October 8, 2014
Metadata Updated Date December 18, 2017
Publisher GESDISC
Unique Identifier C197859242-GSFCS4PA
Maintainer
GEORGE HUFFMAN
Maintainer Email
Id {$oid: 55942a61c63a7fe59b49619c}
Public Access Level public
Data Update Frequency irregular
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 225461ef-872b-49f5-8f0c-bad130b3d041
Harvest Source Id 39e4ad2a-47ca-4507-8258-852babd0fd99
Harvest Source Title NASA Data.json
Data First Published 2011-07-19T00:00:00.000Z
Homepage URL http://reverb.echo.nasa.gov/reverb?selected=C197859242-GSFCS4PA
Language en-US
License http://www.usa.gov/publicdomain/label/1.0/
Metadata Type geospatial
Data Last Modified 2015-03-19T00:00:00.000Z
Program Code 026:001
Publisher Hierarchy U.S. Government > National Aeronautics and Space Administration > GESDISC
Rights None
Source Datajson Identifier True
Source Hash 557f7ec648158af03e7aec3a98aa545ab84df532
Source Schema Version 1.1
Spatial -180.0 -50.0 180.0 50.0
Temporal R/1997-12-31T00:00:00Z/P1Y
Category geospatial

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