Schmidt, K. Sebastian and Pilewskie, Peter and Mayer, B. and Wendisch, Manfred and Kindel, Bruce and Platnick, Steven and King, Michael D. and Wind, Gala and Arnold, G. Tom and Heymsfield, Gerald and Tian, Lin and Kalesse, Heike (2010) Apparent absorption of solar spectral irradiance in heterogeneous ice clouds. Journal of Geophysical Research, 115 (D00J22), pp. 1-12. Wiley. doi: 10.1029/2009JD013124.
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Official URL: http://www.agu.org/journals/jd/jd1020/2009JD013124/2009JD013124.pdf
Abstract
Coordinated flight legs of two aircraft above and below extended ice clouds played an important role in the Tropical Composition, Cloud and Climate Coupling Experiment (Costa Rica, 2007). The Solar Spectral Flux Radiometer measured up- and downward irradiance on the high-altitude (ER-2) and the low-altitude (DC-8) aircraft, which allowed deriving apparent absorption on a point-by-point basis along the flight track. Apparent absorption is the vertical divergence of irradiance, calculated from the difference of net flux at the top and bottom of a cloud. While this is the only practical method of deriving absorption from aircraft radiation measurements, it differs from true absorption when horizontal flux divergence is nonzero. Differences between true and apparent absorption are inevitable in any inhomogeneous atmosphere, especially clouds. We show, for the first time, the spectral shape of measured apparent absorption and compare with results from a three-dimensional radiative transfer model. The model cloud field is created from optical thickness and effective radius retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) Airborne Simulator and from reflectivity profiles from the Cloud Radar System, both on board the ER-2. Although the spectral shape is reproduced by the model calculations, the measured apparent absorption in the visible spectral range is higher than the model results along extended parts of the flight leg. This is possibly due to a net loss of photons into neighboring cirrus-free areas that are not contained within the model domain
Item URL in elib: | https://elib.dlr.de/65944/ | |||||||||||||||||||||||||||||||||||||||
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Document Type: | Article | |||||||||||||||||||||||||||||||||||||||
Title: | Apparent absorption of solar spectral irradiance in heterogeneous ice clouds | |||||||||||||||||||||||||||||||||||||||
Authors: |
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Date: | 2010 | |||||||||||||||||||||||||||||||||||||||
Journal or Publication Title: | Journal of Geophysical Research | |||||||||||||||||||||||||||||||||||||||
Refereed publication: | Yes | |||||||||||||||||||||||||||||||||||||||
Open Access: | Yes | |||||||||||||||||||||||||||||||||||||||
Gold Open Access: | No | |||||||||||||||||||||||||||||||||||||||
In SCOPUS: | Yes | |||||||||||||||||||||||||||||||||||||||
In ISI Web of Science: | Yes | |||||||||||||||||||||||||||||||||||||||
Volume: | 115 | |||||||||||||||||||||||||||||||||||||||
DOI : | 10.1029/2009JD013124 | |||||||||||||||||||||||||||||||||||||||
Page Range: | pp. 1-12 | |||||||||||||||||||||||||||||||||||||||
Publisher: | Wiley | |||||||||||||||||||||||||||||||||||||||
Status: | Published | |||||||||||||||||||||||||||||||||||||||
Keywords: | ice cloud absorption, 3-D radiative transfer, solar spectral measurements | |||||||||||||||||||||||||||||||||||||||
HGF - Research field: | Aeronautics, Space and Transport (old) | |||||||||||||||||||||||||||||||||||||||
HGF - Program: | Space (old) | |||||||||||||||||||||||||||||||||||||||
HGF - Program Themes: | W EO - Erdbeobachtung | |||||||||||||||||||||||||||||||||||||||
DLR - Research area: | Space | |||||||||||||||||||||||||||||||||||||||
DLR - Program: | W EO - Erdbeobachtung | |||||||||||||||||||||||||||||||||||||||
DLR - Research theme (Project): | W - Vorhaben Atmosphären- und Klimaforschung (old) | |||||||||||||||||||||||||||||||||||||||
Location: | Oberpfaffenhofen | |||||||||||||||||||||||||||||||||||||||
Institutes and Institutions: | Institute of Atmospheric Physics > Atmospheric Remote Sensing | |||||||||||||||||||||||||||||||||||||||
Deposited By: | Freund, Jana | |||||||||||||||||||||||||||||||||||||||
Deposited On: | 28 Oct 2010 18:45 | |||||||||||||||||||||||||||||||||||||||
Last Modified: | 31 Jul 2019 19:29 |
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