ISCCP PROJECT STATUS REPORT

NUMBER 113

DATE: 01/05/93

CENTER ACTIVITIES

Sector Processing Center (SPC):

During November, NOA, JMA, AES, and ESA processed greater than 98% of A data into B1/B2 data. CSU collected more than 72% of METEOSAT-3 data.Normal operations were reported by NOA, JMA, AES and ESA.AES lost B1, but not B2, data for 1-3 November because of media damage.CSU collected 72% of METEOSAT-3 data; collection was hampered by problems with the PC controller and with freezing of the antenna.

Special Area Processing Center (SAPC):No report received.

Satellite Calibration Center (SCC):The SCC received AC data for November 92 for GOES-7 and GMS-4 and for October - November 92 for METEOSAT-3 and METEOSAT-4. BC data for for METEOSAT-3 for July 92 and for GOES-7 for August 92 were sent to the GPC this month.

Global Processing Center (GPC):The GPC continued to receive B2 data, BC data and correlative data in a routine manner.Production of NOAA-11 (preliminary) B3 data is current.Production of NOAA-12 (preliminary) B3 data is current.Production of METEOSAT-4 (preliminary) B3 data is current.Production of METEOSAT-3 (at 50W) B3 data has not started yet.Production of GOES-7 (preliminary) B3 data is current. The B2 data delivery backlog includes March - June 92.Production of GMS-4 (preliminary) B3 data is current.Production of all INSAT-1 (preliminary) B3 data has been completed. Final calibrations have been completed; however, there are significant uncertainties associated with complicated variations in the calibration monitoring statistics. Test production of cloud data using 86 and 87 data and a comparison to overlapping results from the polar orbiter, METEOSAT and GMS satellites will be used as a final check on the calibration.The new calibration dataset has been completed covering all B3 data, except INSAT, through June 91. Data tapes are being prepared for shipment to the ICA. The INSAT dataset will be produced once testing of the final calibration is completed.Production of the ice/snow correlative dataset is current. Inquiries are being made by NOAA to arrange for monthly delivery of the ice/snow datasets to the GPC. Re-processing of the whole TOVS dataset has now been completed through December 89.Production of C1/C2 data for May and June 91 has been completed and the data shipped to the ICA. C1/C2 data for March 90 are being re-done because the ozone abundances from TOVS data were missing over a significant fraction of the globe for most of this month.Additional comparisons of the ISCCP cloud amounts with surface observations have been completed. Previously, results of comparisons to over 400,000 individual observations were reported in a draft paper sent to all participants. These results showed an rms disagreement of about 7%, but also identified the source of very large disagreements as caused by differences in the effective area observed by the surface observer and the satellite. To complete that story, the comparison was repeated after averaging the surface and satellite datasets over one month to determine how much of the rms disagreement is truly random (ie, errors cancel in the average). This comparison shows that the rms disagreement between the monthly mean ISCCP and surface observation cloud amounts is only 3%, indicating a reduction in "error" that is slightly smaller than expected if all differences represent random error. However, this "error" is three times smaller than the predicted sampling error, which is consistent with large correlation space and time scales for cloudiness. Moreover, we were able to demonstrate the same pattern and magnitude of disagreement in cloud amounts between adjacent surface stations as between a surface station and the satellite. The paper describing the algorithm and these validation studies has been accepted for publication, subject to being divided into three papers: algorithm description and statistical verification, validation of clear radiances and cloud amounts, and comparisons to other cloud climatologies.

ISCCP Central Archive (ICA):The ICA continued to receive B1 data from NOA, AES, ESA, CSU and JMA and B3 and C data from the GPC in a routine manner.

SATELLITE HEALTHThe health of GMS-4, METEOSAT-3 (at 50 W), METEOSAT-4, METEOSAT-5, GOES-7, NOAA-11, and NOAA-12 remained good.

DATA DELIVEREDStage B3: July 83 - June 91Stage CD: July 83 - December 91Stage C1: July 83 - June 91Stage C2: July 83 - December 90

OPEN ITEMSDelivering the backlog of GOES-7 B1/B2 data for March, April, May and June 92 to the GPC.Delivery backlog for B3 data = 11 months (with respect to planned schedule). B3 data for 96 months have been archived.Delivery backlog for C1/C2 data = 11 months (with respect to planned schedule). C1 data for 96 months have been archived.