Title :
Retrieving cloud fraction in the field-of-view of a high-spectral resolution infrared radiometer
Author :
Turner, D.D. ; Holz, R.E.
Author_Institution :
Climate Phys. Group, Pacific Northwest Nat. Lab., Richland, WA, USA
fDate :
7/1/2005 12:00:00 AM
Abstract :
The combination of radiance from both clear and cloudy regions of sky within the instrument´s field of view (FOV) adds significant uncertainty to retrievals of atmospheric state profiles and cloud microphysical properties from infrared spectroradiometers. We use observations of radiance from both the 8-13 and 3-5 μm bands to retrieve estimates of the cloud fraction in the instrument´s FOV, as well as microphysical cloud properties, from high-spectral-resolution infrared radiometers. Cloud fraction derived from imagers as well as high-time-resolution observations show good agreement and high correlation with our derived cloud fraction values. This is shown for both ground-based and aircraft-based observations. We also demonstrate that the use of the additional information in the 3-5 μm band extends the dynamic range and accuracy of microphysical properties that can be retrieved from infrared radiance data.
Keywords :
atmospheric measuring apparatus; atmospheric techniques; clouds; infrared imaging; radiometers; 3 to 5 micron; 8 to 13 micron; aircraft-based observations; atmospheric state profiles; clear sky radiance; cloud fraction retrieval; cloud microphysical properties; cloudy regions; field of view; ground-based observations; high-spectral resolution infrared radiometer; infrared spectroradiometers; microphysical cloud properties; Atmospheric measurements; Clouds; Energy measurement; Information retrieval; Infrared spectra; Instruments; Laboratories; Microwave radiometry; Signal processing; Spectroradiometers; Clouds; high spectral resolution; infrared measurements; remote sensing;
Journal_Title :
Geoscience and Remote Sensing Letters, IEEE
DOI :
10.1109/LGRS.2005.850533