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TRMM Microwave Imager (TMI) Level 3 Monthly 5° x 5° Oceanic Rainfall (3A11)

Data Access for

3A11:  http://mirador.gsfc.nasa.gov/cgi-bin/mirador/presentNavigation.pl?tree=project&dataset=3A11%20%28Version%20007%29:%20Monthly%205%20x%205%20degree%20Oceanic%20Rainfall&project=TRMM&dataGroup=Gridded&version=007

 


Contents:

Summary

This document provides basic information on 3A11, TMI Monthly 5° x 5° Oceanic Rainfall Product. Algorithm 3A11 estimates monthly rain from the histogram of the brightness temperatures obtained from TMI calibration (1B11). This histogram is matched to a log-normally distributed rain rate distribution via a rain rate-brightness temperature relation. A beam-filling correction is applied to account for the non-uniformly filled field-of-view of the TMI sensor. Outputs are monthly surface rain rates and freezing heights for 5° x 5° grid boxes.

Data Flow Description

TMI Level 1A ==> 1B11 Calibrated TMI brightness temperatures ==> 3A11 TMI Monthly Oceanic Rainfall

The data flow of all products are shown in Satellite Algorithm Flow Diagram.

Data Set Description

Data Characteristics

Temporal Coverage Start Date: 1998-01-01; Stop Date: -
Geographic Coverage Latitude: 40°S - 40°N; Longitude:180°W - 180°E
Temporal Resolution Monthly
Horizontal Resolution 5° x 5°; nlat = 16, nlon = 72
Average File Size Compressed: ~23 KB; Original: ~53 KB
File Type HDF



Data Format Structure

The following table summarizes the contents and structure of the TMI monthly oceanic rainfall (3A11) product. Further information can be found in, File Specifications for TRMM Products - Version 7.00

 

Data Format Structure for 3A11, TMI Monthly Oceanic Rainfall
Name Type Record
Size
(byte)
Dim Size
(# of Records)
Scaled
by
Range Unit Description
ECS Core Metadata Char Attribute 10,000  - - - - ECS Core Metadata
PS Metadata Char Attribute 10,000  - - - - Product Specific Metadata
GridStructure Char Attribute 5,000  - - - - GridStructure gives the specification of the geometry of the grids.
Monthly Rainfall Float SDS 4 nlat*nlon - 0.0 ~ 3000.0 mm The Monthly Rainfall is the surface rainfall over oceans in 5° x 5° boxes from 40°N x 40°S.
Number of Samples Integer SDS nlat*nlon - 0 ~ 500,000 - The Number of Samples is that over oceans in 5° x 5° boxes for one month.
Chi Square Fit Integer SDS nlat*nlon - 1 ~ 1,000,000,000 - The Chi Square Fit indicates how well the histogram of brightness temperatures fits the lognormal distribution function in 5° x 5° boxes for one month.
Freezing Level Float SDS 4 nlat*nlon - 0.00 ~ 6.00 km The Freezing Level is the estimated height of 0°C isotherm over oceans in 5° x 5° boxes for one month.
T_0 Float SDS 4 nlat*nlon - 160.0 ~ 180.0 oK The T_0 is the mean of non-raining brightness temperatures over oceans in 5° x 5° boxes for one month.
r_0 Float SDS 4 nlat*nlon - 0.00 ~ 15.00 mm
h-1
The r_0 is the logarithmic mean rain rate over oceans in 5° x 5° boxes for one month.
Sigma_r Float SDS 4 nlat*nlon - 0.00 ~ 1.00 mm
h-1
The Sigma_r(sr) is the standard deviation of logarithmic rain rates over oceans in 5° x 5° boxes for one month.
Probability of Rain Float SDS 4 nlat*nlon - 0.000 ~ 1.000 - The Probability of Rain is that over oceans in 5° x 5° boxes for one month.
Quality Indicator 1 Integer SDS nlat*nlon - - - TBD.
Quality Indicator 2 Integer SDS nlat*nlon - - - TBD.
Quality Indicator 3 Integer SDS nlat*nlon - - - TBD.
Spare Integer SDS nlat*nlon - - - TBD.
Note for all SDS: Data on land areas are assigned the value -9999.

TRMM 3A11 can be accessed and ordered from Mirador at 

http://mirador.gsfc.nasa.gov/cgi-bin/mirador/presentNavigation.pl?tree=project&dataset=3A11%20%28Version%20007%29:%20Monthly%205%20x%205%20degree%20Oceanic%20Rainfall&project=TRMM&dataGroup=Gridded&version=007

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Appendix

 
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Last updated: Mar 18, 2013 02:47 PM ET
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