NUMBER 119

DATE: 07/07/93

Sector Processing Center (SPC):

During May, NOA, JMA, AES, CSU and ESA processed greater than 90% of A data into B1/B2 data.Normal operations were reported by NOA, JMA, CSU and ESA.AES reported loss of 5 images because of another power fluctuation and of another 17 images during a power outage and subsequent transformer replacement. B1 (but not B2) data were lost from 16 May through 23 May because of a faulty tape drive.ESA reported operating METEOSAT-5 from 0830 on 4 May through 0900 on 7 May while the infrared sensors on METEOSAT-4 were undergoing routine decontamination.

Special Area Processing Center (SAPC):

No report received.

Satellite Calibration Center (SCC):

The SCC received AC data for April 93 from NOAA-11 and for May 93 from GMS-4, METEOSAT-3, METEOSAT-4, GOES-7 and NOAA-11. BC data for METEOSAT-3 for January 93 and for GMS-4 for April 93 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 GOES-7 (preliminary) B3 data is current. The B2 data delivery backlog includes April - June 92.Production of METEOSAT-3 B3 data has not started yet. Final testing of software is underway.Production of METEOSAT-4/5 (preliminary) B3 data is current.Production of GMS-4 (preliminary) B3 data is current.Production of all INSAT-1 (preliminary) B3 data for January 86 through March 89 has been completed. Apparent short-term calibration variations are being investigated before delivery of INSAT-1 B3 data.New anisotropic scattering models have been developed for use in monitoring the calibrations of the AVHRR. These models, one for each of eight major vegetation types, plus water and ice/snow, are developed by collecting one year of surface reflectance data over the whole globe (NOAA-9 is used because the calibration is known independently), sorting the values by surface type and viewing geometry, and fitting a function that insures reciprocity of solar and satellite zenith angle dependence. This treatment of the angular dependence of surface reflectances is more detailed than previously used and should reduce systematic errors in the normalization of one AVHRR to the next in sequence. Because the NOAA-9 AVHRR has the best understood and most accurately measured calibration, it will become the calibration standard for the re-processed ISCCP datasets. After further testing of these scattering models, the normalizations and trend corrections for AVHRR visible calibration will be re-calculated. We will also redo the infrared normalization based on results from the AVHRR PATHFINDER project.Production of the ice/snow correlative dataset is current. Sea ice data for 92 have not yet been received from NOAA.Software revisions for processing of TOVS after the format changes in 92 are still in progress. Testing is completed for the new software required by the first format change and some processing has been completed.In the old analysis, cloud optical thicknesses were retrieved assuming that all clouds are composed on water spheres with an effective radius of 10 m. Results from both FIRE and ICE show that, for certain viewing geometries, this assumption produces a significant positive bias at the lowest values for ice phase clouds. A scheme for translating optical thickness values from a water sphere model to an ice crystal model has been developed by P. Minnis at NASA Langley. This scheme has been installed into the ISCCP analysis code. To test the new method and determine the improvement in the results, both the old and the new method being applied to matched observations from pairs of satellites viewing the same scene from different angles.

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.

The health of GMS-4, METEOSAT-3 (at 75 W), METEOSAT-4, METEOSAT-5, GOES-7, and NOAA-11 remained good. NOAA-12 has started experiencing higher than normal scan motor jitter that produces noticeable noise levels in Channel 3 of the AVHRR and in some short wavelength channels of HIRS. Changes in instrument operating temperature have not alleviated the problem. Launch of NOAA-I is scheduled for 14 July 93.

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

Delivering the backlog of GOES-7 B1/B2 data for April, May and June 92 to the GPC.

Delivering sea ice correlative data for 92 to the GPC.

Delivery backlog for B3 data = 17 months (with respect to planned schedule). B3 data for 96 months have been archived.

Delivery backlog for C1/C2 data = 17 months (with respect to planned schedule). C1 data for 96 months have been archived.