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Title: Error estimates of spaceborne passive microwave retrievals of cloud liquid water over land

Abstract

Cloud liquid water path (LWP) retrievals from the Special Sensor Microwave/Imager (SSM/I) and surface microwave radiometers are compared over land to assess the errors in selected satellite methods. These techniques require surface emissivity composites created from SSM/I and infrared (IR) data. Two different physical methods are tested: a single-channel (SC) approach; and a normalized polarization difference (NPD) approach. Comparisons were made at four sites in Oklahoma and Kansas over an 1-month period. The 85.5-GHz NPD method was the most accurate and robust under most conditions. An error analysis shows that the method`s random errors are dominated by uncertainties in the surface emissivity and instrument noise. Since the SC method is more prone to systematic errors (such as surface emissivity errors caused by rain events), it initially compared poorly to the ground observations. After filtering for rain events, the comparisons improved. Overall, the root mean square (rms) errors ranged from 0.12 to 0.14 kg m{sup {minus}2}, suggesting these methods can provide, at best, three categories of cloud LWP. It is anticipated that the techniques and strategies developed in this study, and prior related studies, to analyze passive microwave data will be requisite for maximizing the information content of future instruments.

Authors:
; ; ; ;  [1]
  1. Colorado State Univ., Fort Collins, CO (United States). Cooperative Inst. for Research in the Atmosphere
Publication Date:
Sponsoring Org.:
USDOE Office of Energy Research, Washington, DC (United States); Department of Defense, Washington, DC (United States)
OSTI Identifier:
355579
Resource Type:
Journal Article
Journal Name:
IEEE Transactions on Geoscience and Remote Sensing
Additional Journal Information:
Journal Volume: 37; Journal Issue: 2Pt1; Other Information: PBD: Mar 1999
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; REMOTE SENSING; CLOUDS; WATER VAPOR; RADIOMETERS; SATELLITES; DATA COVARIANCES; MICROWAVE RADIATION; CLIMATES

Citation Formats

Greenwald, T J, Combs, C L, Jones, A S, Randel, D L, and Vonder Haar, T H. Error estimates of spaceborne passive microwave retrievals of cloud liquid water over land. United States: N. p., 1999. Web. doi:10.1109/36.752195.
Greenwald, T J, Combs, C L, Jones, A S, Randel, D L, & Vonder Haar, T H. Error estimates of spaceborne passive microwave retrievals of cloud liquid water over land. United States. https://doi.org/10.1109/36.752195
Greenwald, T J, Combs, C L, Jones, A S, Randel, D L, and Vonder Haar, T H. 1999. "Error estimates of spaceborne passive microwave retrievals of cloud liquid water over land". United States. https://doi.org/10.1109/36.752195.
@article{osti_355579,
title = {Error estimates of spaceborne passive microwave retrievals of cloud liquid water over land},
author = {Greenwald, T J and Combs, C L and Jones, A S and Randel, D L and Vonder Haar, T H},
abstractNote = {Cloud liquid water path (LWP) retrievals from the Special Sensor Microwave/Imager (SSM/I) and surface microwave radiometers are compared over land to assess the errors in selected satellite methods. These techniques require surface emissivity composites created from SSM/I and infrared (IR) data. Two different physical methods are tested: a single-channel (SC) approach; and a normalized polarization difference (NPD) approach. Comparisons were made at four sites in Oklahoma and Kansas over an 1-month period. The 85.5-GHz NPD method was the most accurate and robust under most conditions. An error analysis shows that the method`s random errors are dominated by uncertainties in the surface emissivity and instrument noise. Since the SC method is more prone to systematic errors (such as surface emissivity errors caused by rain events), it initially compared poorly to the ground observations. After filtering for rain events, the comparisons improved. Overall, the root mean square (rms) errors ranged from 0.12 to 0.14 kg m{sup {minus}2}, suggesting these methods can provide, at best, three categories of cloud LWP. It is anticipated that the techniques and strategies developed in this study, and prior related studies, to analyze passive microwave data will be requisite for maximizing the information content of future instruments.},
doi = {10.1109/36.752195},
url = {https://www.osti.gov/biblio/355579}, journal = {IEEE Transactions on Geoscience and Remote Sensing},
number = 2Pt1,
volume = 37,
place = {United States},
year = {Mon Mar 01 00:00:00 EST 1999},
month = {Mon Mar 01 00:00:00 EST 1999}
}