International Satellite Cloud Climatology Project (ISCCP)

Current Project Status: January 2008

ISCCP completed its 24^th year of data collection on 30 June 2007. Radiances from all operating meteorological satellites are being routinely collected by the cognizant Sector Processing Centers (SPC) and delivered to the Global Processing Center (GPC) in accordance with project requirements. All project datasets are now being delivered via Internet. Currently operating satellites are NOAA-17, NOAA-18, MTSAT-1R, FY-2C, GOES-10, GOES-11, GOES-12, METEOSAT-7, METEOSAT-9 with METOP-1, MTSAT-2, FY-2D, GOES-13, METEOSAT-6 and METEOSAT-8 in reserve. METEOSAT-5, located at 63°E longitude, was replaced by METEOSAT-7, located at 57° longitude, in February 2007 to provide coverage of the Indian Ocean -- Asia sector. GOES-10 has been moved to 60°W and is being operated by Brazil; data from this satellite will be contributed to ISCCP. It has not yet been confirmed whether METOP-1 will provide data for the “morning” polar orbit in place of NOAA-17 or not. If all of these additional satellites begin supplying data (more than the minimum required), the data products will be re-designed slightly to process and accommodate all of these.

The Satellite Calibration Center (SCC) in Lannion, France, provides monthly satellite-to-satellite radiance normalization for three wavelength channels when available, nominally at 0.6, 11 and 12 μm. Normalization of the 6.7 μm channels ceased because the HIRS instrument on NOAA-17 and 18 does not produce adequate quality data at this wavelength. Normalization data are complete through October 2007 as scheduled.

The GPC monitors the calibration of the polar orbiting radiometers (AVHRR) that serve as the reference standard for the radiance data. Monitoring results are complete through September 2007. There are still some questions about the infrared calibration for NOAA-18 that are being investigated. These results will be compared with the calibrations of MODIS on TERRA and AQUA later this year. Calibration information posted on the ISCCP Web page is complete through June 2007.

Routine archival of Stage B3 data is complete through June 2007 (24 years).

Atmospheric temperature and humidity profiles and the sea ice and snow correlative datasets are complete through June 2007. Changes in the sea ice product at the beginning of 2007 had to be accommodated in the processing.

Stage DX, D1 and D2 data have been completed for July 1983 through June 2007 (24 years). All D2 data are now on-line on the ISCCP Web site.

A complete survey of cloud particle sizes, both liquid and ice, has been completed and will be released in a few months. These data will also be combined with the aerosol product produced by the Global Aerosol Climatology Project to facilitate studies of cloud-aerosol interactions.

Complete datasets currently available at the ICA are:

Stage B3 and BT:                   July 1983        —          June 2007

Atmospheric data:                  July 1983        —          June 2007

Sea ice and snow data:           July 1983        —          June 2007

Stage DX, D1 and D2:           July 1983        —          June 2007

            The ISCCP Web pages can be found at

http://isccp.giss.nasa.gov

A separate Home page for the GEWEX Cloud System Study - Data Integration for Model Evaluation (GCSS - DIME) can be found at

http://gcss-dime.giss.nasa.gov

The survey of midlatitude cyclone cloudiness produced by combining the NCEP re-analysis with ISCCP has been completed; the results will be released and posted on the ISCCP Web site by the spring of 2008.

A new “cluster” analysis procedure has been developed that identifies distinctive patterns in the two-dimensional histograms of cloud properties (cloud top pressure and optical thickness) contained in the D1 dataset. The results of a survey of the whole ISCCP dataset have been posted on the ISCCP website for four regions: Tropics (+ 15° latitude), Extended Low-Latitudes (+ 35°), Northern Midlatitudes (30° to 65°) and Southern Midlatitudes (-30° to -65°).

New scientific results based on the ISCCP datasets are reported in:

Zhang, Y-C., W.B. Rossow and P.W. Stackhouse, 2007: Comparison of different global information sources used in surface radiative flux calculation: Radiative properties of the surface. J. Geophys. Res., 112, D01102, doi: 10.1029/2005JD007008, (1-20).

Rossow, W.B., and C. Pearl, 2007: 22-year survey of tropical convection penetrating into the lower stratosphere. Geophys. Res. Lett., 34, L04803, doi: 10.1029/2006GL028635, (1-4).

Mishchenko, M.I., I.V. Geogdzhayev, W.B. Rossow, B. Cairns, B.E. Carlson, A.A. Lacis and L.D. Travis, 2007: Long-term satellite record reveals likely aerosol trend. Science, 315, 1543.

Mishchenko, M.I., I.V. Geogdzhayev, B. Cairns, B.E. Carlson, J. Chowdhary, A.A. Lacis, L. Liu W.B. Rossow and L.D. Travis, 2007: Past, present, and future of global aerosol climatologies derived from satellite observations: A perspective. J. Quant. Spectrosc. Radiat. Trans., 106, 325-347.

Romanou, A., B. Liepert, G. Schmidt, W. Rossow and Y-C. Zhang, 2007: 20^th century reduction in surface solar irradiance in simulations and observations. Geophys. Res. Lett., 34, L05713, doi: 10.1029/2006GL028356, (1-5).

Zhang, Y-C., W.B. Rossow, P. Stackhouse, A. Romanou and B.A. Wielicki, 2007: Decadal variations of global energy and ocean heat budget and meridional energy transports inferred from recent global data sets. J. Geophys. Res., 112, D22101, doi 10.1029/2007JD008435, (1-8).

Tselioudis, G., W.B. Rossow and A. Sheffield, 2007: Characteristic scales of variation of tropical meteorological states revealed by associated and distinctive mesoscale mixtures of cloud properties. J. Climate, (in preparation).

Zhang, Y-C., W.B. Rossow, C.N. Long and E.G. Dutton, 2007: Exploiting the diurnal variations of surface radiative fluxes to evaluate the ISCCP-FD flux calculations using surface observations from BSRN, ARM and SURFRAD. J. Geophys. Res., (in preparation).

Rossow, W.B., and V. Golea, 2007: Comparison of satellite-based and radar/lidar-based cloud datasets in the Arctic. J. Climate, (in preparation).

Rossow, W.B., G. Tselioudis, M. Bauer and A. Sheffield, 2008: Cloud processes in midlatitude cyclones: Cloud spatial structure and evolution. J. Climate, (in preparation).

Rossow, W.B., and V. Golea, 2008: Factors that might affect ISCCP determinations of long-term cloud cover changes. J. Climate, (in preparation).

Rossow, W.B., C. Pearl and Q. Han, 2008: Global, 20-yr survey of effective cloud particle sizes for liquid and ice clouds based on the ISCCP products. J. Climate, (in preparation).