Articles | Volume 14, issue 6
Research article
02 Jun 2021
Research article |  | 02 Jun 2021

MICRU: an effective cloud fraction algorithm designed for UV–vis satellite instruments with large viewing angles

Holger Sihler, Steffen Beirle, Steffen Dörner, Marloes Gutenstein-Penning de Vries, Christoph Hörmann, Christian Borger, Simon Warnach, and Thomas Wagner

Data sets

MICRU effective cloud fractions from GOME-2A Holger Sihler and Thomas Wagner

MODIS/Terra Snow Cover 8-Day L3 Global 0.05Deg CMG, Version 6, 2007-2013 D. K. Hall and G. A. Riggs

Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data, Version 1, NSIDC-0051, 2007-2013 D. J. Cavalieri, C. L. Parkinson, P. Gloersen, and H. J. Zwally

Global 30 Arc-Second Elevation (GTOPO30) USGS

Global Self-consistent Hierarchical High-resolution Geography (GSHHG), Version 2.3.7 NOAA

GOME-2A Absorbing Aerosol Index MSC (R1) - Metop AC SAF

GOME-2A Absorbing Aerosol Index PMD (R1) - Metop AC SAF

Short summary
MICRU is an algorithm for the retrieval of effective cloud fractions (CFs) from satellite measurements. CFs describe the amount of clouds, which have a significant impact on the vertical sensitivity profile of trace gases like NO2 and HCHO. MICRU retrieves small CFs with an accuracy of 0.04 over the entire satellite swath. It features an empirical surface reflectivity model accounting for physical anisotropy (BRDF, sun glitter) and instrumental effects. MICRU is also applicable to imager data.