TRMM Rain Rate Validation: Regional Bias of TRMM Algorithms

Table of Contents

• Overview
• Data
• Methods
• Results
• References

Overview

Rain rates from gauge measurements and TRMM algorithms were compared to evaluate their regional biases. The comparison results show possibly region-specific seasonal differences in the bias patterns. For global applications of TRMM algorithms, biases for different regions need to be established.

Data

TRMM Data
3B42	3B43	3G68 TMI	3G68 TPR	3G68 TCI

Methods

• Study Sites: Oklahoma, U.S.; Argentina
• Time Series: Monthly time series of TRMM and gauge rain rates from January 1998 to November 2003.
• Linear Regression: A linear relationship presented by a 'best-fit' straight line on a scatter plot of TRMM versus gauge rain rates.
• Bias: To determine if TRMM rain rates over or under estimate gauge measurements.
• T-test: To determine the significance (p=0.05) of the differences between the means of TRMM and gauge rain rates.

Results (Oklahoma, U.S.)

Click on image to enlarge Time Series Linear Regression Bias T-test

References

Chiu, L., C. Lim, and W. Teng (2004), Development of Agricultural Information System: Comparison of TRMM and climate division rain rates in Oklahoma, 2nd International TRMM Conference, Nara, Japan.

Chiu, L.S., Z. Liu, J. Vongsaard, S. Morain, A. Budge, P. Neville, and C. Bales (2006), Comparison of TRMM and water district rain rates over New Mexico. Advances in Atmospheric Sciences, 23:1:1-13.

Shin, D.-B., L. S. Chiu, and M. Kafatos (2001), Comparison of the monthly precipitation derived from the TRMM satellite. Geophysical Research Letters, 28:5:795-798.

Post-TRMM Plan