Assessing the Diurnal Cycle of Cloud Properties Using SEVIRI and MODIS
Meirink, Jan Fokke; Maddux, Brent
Royal Dutch Meteorological Institute(KNMI), NETHERLANDS
The diurnal cycle represents a major source of variability and uncertainty in the global cloud field. The assessment of the diurnal cycle of cloud properties is important for understanding the difference that are observed among satellite data records in both space and time. Constructing heritage or long term data records requires stitching data from geostationary and polar orbiting instruments together. From a climate perspective this creates significant uncertainty with respect to understanding how clouds are changing. Changes in cloud cover over the diurnal cycle have long been recognized and studied from both ground and space. However, relatively little is known of the diurnal changes in cloud properties, e.g. optical thickness, effective radii and water path. We will present a statistical assessment of the diurnal changes in cloud properties using 5 years of data from the Spinning Enhanced Visible and Infrared Imager(SEVIRI) and Moderate Resolution Imaging Spectroradiometer (MODIS). SEVIRI provides high temporal and spatial resolution information about cloud optical properties from geostationary orbit, and MODIS provides near-global coverage. By linking the two instrument data records we can assess the diurnal cycle across multiple cloud types, the annual cycle, and a wide range of geographical locations. This work was conducted under the auspices of the Climate Change Initiative (ESA-CCI) for clouds.