Retrieval of cloud optical depth and particle effective radius at high latitudes using visible and thermal satellite data

Jeffrey R. Key

doi:10.1117/12.228928

27 December 1995 Retrieval of cloud optical depth and particle effective radius at high latitudes using visible and thermal satellite data

Jeffrey R. Key

Author Affiliations +

Proceedings Volume 2578, Passive Infrared Remote Sensing of Clouds and the Atmosphere III; (1995) https://doi.org/10.1117/12.228928
Event: Satellite Remote Sensing II, 1995, Paris, France

Abstract

The retrieval of cloud optical depth and particle radius is relatively straightforward for water clouds over low-albedo surfaces during the daylight hours. Under these conditions the nearly orthogonal relationship between optical depth and effective radius at one absorbing and one non-absorbing wavelength (e.g., the AVHRR 0.6 and 3.7 micron channels) can be exploited. However, high latitudes are characterized by highly-reflective surfaces and many months without solar radiation. The bright surfaces give rise to multiple solutions for thin clouds, and the long polar night precludes the use of shortwave channels. Thermal bands are therefore used to resolve the ambiguity when there are multiple solutions in the shortwave retrievals and to provide a solution when there is no solar radiation. But thermal methods must account for another unknown: the cloud height. Investigations using modeled radiances for a range of cloud heights show that two pairs of three thermal channels at 3.7, 11, and 12 microns can be used to obtain a unique solution. Unfortunately, validation data are not yet available so we assess the accuracy of these methods using estimates of surface radiative fluxes.

Citation Download Citation

Jeffrey R. Key "Retrieval of cloud optical depth and particle effective radius at high latitudes using visible and thermal satellite data", Proc. SPIE 2578, Passive Infrared Remote Sensing of Clouds and the Atmosphere III, (27 December 1995); https://doi.org/10.1117/12.228928

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available