Measuring cloud thermodynamic phase with shortwave infrared imaging spectroscopy. Issue 15 (12th August 2016)

• Record Type: Journal Article
• Authors: Thompson, David R.; McCubbin, Ian; Gao, Bo Cai; Green, Robert O.; Matthews, Alyssa A.; Mei, Fan; Meyer, Kerry G.; Platnick, Steven; Schmid, Beat; Tomlinson, Jason; Wilcox, Eric
• Is Part Of: Journal of geophysical research. Volume 121:Issue 15(2016)
• Page Start: 9174
• Page End: 9190
• Publication Date: 2016-08-12
• Subjects: imaging spectroscopy -- remote sensing -- cloud phase -- shortwave infrared -- AVIRIS‐C -- Arm Airborne Facility; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1002/2016JD024999
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: Shortwave Infrared imaging spectroscopy enables accurate remote mapping of cloud thermodynamic phase at high spatial resolution. We describe a measurement strategy to exploit signatures of liquid and ice absorption in cloud top apparent reflectance spectra from 1.4 to 1.8 μm. This signal is generally insensitive to confounding factors such as solar angles, view angles, and surface albedo. We first evaluate the approach in simulation and then apply it to airborne data acquired in the Calwater‐2/ACAPEX campaign of Winter 2015. Here NASA's "Classic" Airborne Visible Infrared Imaging Spectrometer (AVIRIS‐C) remotely observed diverse cloud formations while the U.S. Department of Energy ARM Aerial Facility G‐1 aircraft measured cloud integral and microphysical properties in situ. The coincident measurements demonstrate good separation of the thermodynamic phases for relatively homogeneous clouds. Key Points: Remote shortwave infrared spectroscopy can accurately determine cloud thermodynamic phase under certain conditions We demonstrate cloud phase retrievals in simulation using radiative transfer models We evaluate performance with coincident remote and in situ aircraft observations