The SPARC Water Vapor Assessment II: assessment of satellite measurements of upper tropospheric humidity
Journal article, 2022
Nineteen limb-viewing data sets (occultation, passive thermal, and UV scattering) and two nadir upper tropospheric humidity (UTH) data sets are intercompared and also compared to frost-point hygrometer balloon sondes. The upper troposphere considered here covers the pressure range from 300-100 hPa. UTH is a challenging measurement, because concentrations vary between 2-1000 ppmv (parts per million by volume), with sharp changes in vertical gradients near the tropopause. Cloudiness in this region also makes the measurement challenging. The atmospheric temperature is also highly variable ranging from 180-250 K. The assessment of satellite-measured UTH is based on coincident comparisons with balloon frost-point hygrometer sondes, multi-month mapped comparisons, zonal mean time series comparisons, and coincident satellite-to-satellite comparisons. While the satellite fields show similar features in maps and time series, quantitatively they can differ by a factor of 2 in concentration, with strong dependencies on the amount of UTH. Additionally, time-lag response-corrected Vaisala RS92 radiosondes are compared to satellites and the frost-point hygrometer measurements. In summary, most satellite data sets reviewed here show on average similar to 30 % agreement amongst themselves and frost-point data but with an additional similar to 30 % variability about the mean bias. The Vaisala RS92 sonde, even with a time-lag correction, shows poor behavior for pressures less than 200 hPa.
Author
William G. Read
California Institute of Technology (Caltech)
Gabriele Stiller
Karlsruhe Institute of Technology (KIT)
Stefan Lossow
Karlsruhe Institute of Technology (KIT)
Michael Kiefer
Karlsruhe Institute of Technology (KIT)
Farahnaz Khosrawi
Karlsruhe Institute of Technology (KIT)
Dale Hurst
National Oceanic and Atmospheric Administration
Holger Vomel
National Center for Atmospheric Research
Karen Rosenlof
National Oceanic and Atmospheric Administration
Bianca M. Dinelli
L'Istituto di Scienze dell'Atmosfera e del Clima (CNR-ISAC)
Piera Raspollini
Istituto Di Fisica Applicata Nello Carrara
Gerald E. Nedoluha
Naval Research Laboratory
John C. Gille
University of Colorado at Boulder
National Center for Atmospheric Research
Yasuko Kasai
Japan National Institute of Information and Communications Technology
Patrick Eriksson
Chalmers, Space, Earth and Environment, Geoscience and Remote Sensing
Christopher E. Sioris
York University
Kaley A. Walker
University of Toronto
Katja Weigel
Universität Bremen
John P. Burrows
Universität Bremen
Alexei Rozanov
Universität Bremen
Atmospheric Measurement Techniques
1867-1381 (ISSN) 1867-8548 (eISSN)
Vol. 15 11 3377-3400Subject Categories
Meteorology and Atmospheric Sciences
Geophysics
Physical Geography
DOI
10.5194/amt-15-3377-2022