Paper Info
Title
Assessment of Sampling Effects on Various Satellite-Derived Integrated Water Vapor Datasets Using GPS Measurements in Germany as Reference.
Abstract
Passive imagers on polar-orbiting satellites provide long-term, accurate integrated water vapor (IWV) data sets. However, these climatologies are affected by sampling biases. In Germany, a dense Global Navigation Satellite System network provides accurate IWV measurements not limited by weather conditions and with high temporal resolution. Therefore, they serve as a reference to assess the quality and sampling issues of IWV products from multiple satellite instruments that show different orbital and instrument characteristics. A direct pairwise comparison between one year of IWV data from GPS and satellite instruments reveals overall biases (in kg/m(2y)) of 1.77, 1.36, 1.11, and -0.31 for IASI, MIRS, MODIS, and MODIS-FUB, respectively. Computed monthly means show similar behaviors. No significant impact of averaging time and the low temporal sampling on aggregated satellite IWV data is found, mostly related to the noisy weather conditions in the German domain. In combination with SEVIRI cloud coverage, a change of shape of IWV frequency distributions towards a bi-modal distribution and loss of high IWV values are observed when limiting cases to daytime and clear sky. Overall, sampling affects mean IWV values only marginally, which are rather dominated by the overall retrieval bias, but can lead to significant changes in IWV frequency distributions.
Year
DOI
Venue
2020
10.3390/rs12071170
REMOTE SENSING
Keywords
DocType
Volume
water vapor retrievals,validation,sampling effects,MODIS,MIRS,IASI,GPS
Journal
12
Issue
Citations 
PageRank 
7
0
0.34
References 
Authors
0
6
Name
Order
Citations
PageRank
Cintia Carbajal Henken100.68
Lisa Dirks200.34
Sandra Steinke300.34
Hannes Diedrich400.34
Thomas August500.34
Susanne Crewell6267.63