Cloud Optical Properties from the Multi-Filter Shadowband Radiometer (MFRSRCLDOD): An ARM Value-Added Product

Technical Report · Wed Dec 01 04:00:00 EST 2004

DOI:https://doi.org/10.2172/1020280· OSTI ID:1020280

Turner, DD; Lo, C; Min, Q

The Min and Harrison algorithm has been incorporated into an ARM Value-Added Product (VAP) called MFRSR CLDOD. This version of the VAP (1Min) uses the diffuse transmission at 415 nm from the MFRSR. Therefore, the results are only valid for “horizontally homogeneous” stratiform clouds with optical depths larger than approximately 7. The retrieval assumes a single cloud layer consisting solely of liquid water drops. As specified by Min and Harrison (1996), the wavelength at 415 nm was chosen due to the lack of gaseous absorption and the relatively constant surface albedo (in the absence of snow) at this wavelength. The MFRSR CLDOD VAP (henceforth referred to as “the VAP”) retrieves cloud optical depth (τ) from the MFRSR measurements. If the LWP is available from a coincident MWR observation, then the droplet effective radius (re) can be determined. Knowledge of the estimated re can be used to improve the estimate of τ because there is a slight dependence on the extinction coefficient, single scattering albedo, and asymmetry parameter on effective radius at this wavelength. However, if the MWR’s LWP is not available, then the VAP assumes that re = 8.0 μm. The primary output from the VAP is τ and re.

• Research Organization: DOE Office of Science Atmospheric Radiation Measurement (ARM) Program (United States)
• Sponsoring Organization: USDOE EM Office of Science and Technology (EM-50)
• OSTI ID: 1020280
• Report Number(s): DOE/SC-ARM/TR-047
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ABSORPTION
ALBEDO
ALGORITHMS
ASYMMETRY
CLIMATIC CHANGE
CLOUDS
GOES SATELLITES
OPTICAL PROPERTIES
PROBES
PYRANOMETERS
RADIANT FLUX DENSITY
RADIATIONS
RADIOMETERS
SCATTERING
SNOW
SPECTROMETERS
WAVELENGTHS