NUMBER 93

DATE: 05/06/91

Sector Processing Center (SPC):

During March, NOA, ESA and JMA processed greater than 98% of A data into B1/B2 data.

Normal operations were reported by NOA, ESA and JMA. No report was received from AES.

ESA reported that commissioning of METEOSAT-5 is nearly complete and that routine operations will begin in early May.

NOAA reported shipment of all of the backlog of B2 data for NOAA-10.

In a separate letter, AES announced a reorganization in the Canadian Climate Center: the Satellite Data Archiving System will now be managed by the Systems Development and Implementation Division in the Climate Information Branch (CCID). The new contacts for ISCCP are Mr. Don McKay (Director, CCID) and Mr. Yves Durocher.

JMA also announced a new contact person for ISCCP, Mr. Kenzo Shuto, who is the new head of the Data Processing Department at the Meteorological Satellite Center.

Special Area Processing Center (SAPC):

No reports were received.

Satellite Calibration Center (SCC):

GOES-7 BC data for November-December 90 and January 91 were sent to the GPC.

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. NOAA-11 B3 data have been re-calibrated through May 90 and data through December 89 sent to the ICA. The cause for the small calibration shifts in Channel 4, reported in the last monthly report, are still not known. However, examination of the time records near the south polar overflight time suggest that the explanation of stray sunlight effects still is the best one. These data also show that the effects are completely different for the three IR channels, with Channel 3 affected most and Channel 5 affected least. Small normalization corrections for Channel 4 have been calculated; however, the larger change apparent in December 90 will be checked by comparison to all three geostationary satellite normalizations for that month.

Production of NOAA-10 (preliminary) B3 data is current. Replacement data for the period from late May through early June 89 have been received and re-calibration of these B3 data has resumed.

Production of METEOSAT (preliminary) B3 data is current.

Production of GOES-7 (preliminary) B3 data is current. All GOES-7 B3 data with the incorrect 7-bit count values for visible radiances (April 87 through June 88) have been re-processed to multiply all visible counts by two. These corrected data have been delivered to the ICA. This new version of the calibration has also been tested in the cloud analysis. GOES-7 B3 data for July - December 88 have also been re-calibrated and delivered to the ICA.

Production of GOES-6 B3 data is completed.

Production of GMS-4 (preliminary) B3 data is current. GMS-3 B3 data for July - December 88 have been re-calibrated and delivered to the ICA. Delivery of the corrected B3 data for August and September 87 was delayed because of the discovery of additional problems with the IR calibration in April 87 that also affected all of the B3 data from February - June 87. This problem appears to be caused by a difference in the calibration sent to the SCC and the GPC. These data are being re-processed.

The processing software to convert INSAT-1 B2 data into B3 format is nearing completion. Checking of the nominal and normalized calibrations is underway.

Production of TOVS correlative data is again current. The errors in the 89 and 90 data have been corrected and replacement datasets sent to the ICA.

C1 data for October 87 have been completed. In addition, C1 data for April 89 was processed to support testing of methods to infer surface radiative fluxes from satellite data. These data have been shipped to NASA Langley Research Center, the processing center for the Surface Radiation Budget project.

With all of the problems reported above, repair work on the C1 datasets for February - August 87 is required. The re-analysis of the GMS-3 B3 data for February and August 87 is completed. Re-analysis of GOES-7 B3 data for April 87 is completed.

Representatives of the SCC, CSU (SPC for INSAT) and the GPC have completed a draft of a paper describing the calibration normalization and adjustment procedures applied to the B3 data from geostationary satellites. Also included is a complete history of the calibrations of all the satellite radiometers with significant anomalies highlighted.

ISCCP Central Archive (ICA):

The ICA continued to receive B1 data from NOA, AES, ESA, and JMA and B3 and C data from the GPC in a routine manner.