MODAPS PCR 25-005
| PCR Number | 25-005 |
|---|---|
| Date | 2025-07-29 |
| Initiator | Carol Davidson |
| Abstract | PGE03 6.1.8, PGE06 6.1.12 Updated PGE version to go into operation at MODAPS. See 'Description of Change' for a summary of general changes. |
| Problem Statement | The standard NISE ancillary data, based on the SSMIS product, is slated to be discontinued as of 8/1/25. In order to continue MODIS forward processing, NRT or standard, an alternative snow/ice product is needed. The NSIDC has prepared an alternative NISE_A2 product based on AMSR2 data as a replacement. Using samples of NISE_A2 from NSIDC, we have tested MODIS data, a winter and summer period, and found that the NISE_A2 is an acceptable substitute. The PGEs revised to support this are C6.1 PGE03/CloudMask and PGE06/L2 Clouds, which are the only PGEs that stage NISE data directly for use. |
| Description of Change | The only modifications made to PGE03/CloudMask and PGE06/L2 Clouds was to their respective LoaderModules so that they would stage NISE_A2 inputs instead of NISE inputs; no science code changes were implemented. The difference between NISE and NISE_A2 are in the attached document. Change to using NISE_A2 is only for MODIS C6.1 Aqua and Terra forward processing. |
| Products Affected | MxD35_L2, MxD06_L2, and all downstream products that make use of these datasets as input. Assessment from ATMOS team and LDOPE is that the differences are minimal. |
| Software Affected | PGE03 6.1.8, PGE06 6.1.12 |
| Processing String to Receive the Change | Terra Forward Processing. Aqua Forward Processing. NRT. |
| Downstream Product Effects | C61 products: MxDCSRFM, MxDFMHDR, MxDCSR_G, MxDCSR_D, MxDCSR_8, and MxDCSR_B. |
| Data Granules to be Used for Science Testing | Two tests were run. One using NISE from prior data year and one using NISE_A2 data. The NISE_A2 test processed the data for the period that corresponded to the NISE_A2 data periods. ATMOS team compared the results of both tests, to each other, and to C6.1 holdings and determined using the NISE_A2 that corresponded to the data period was the better approach as the prior year NISE introduced too many differences. LDOPE also reviewed the tests and found that when using the NISE_A2 data they found no differences in the test data as compared to the original C6.1 data. Both LDOPE and ATMOS team recommend moving to NISE_A2 data for leading edge processing when NISE is no longer available. |
| Justification | For continued processing at leading edge with the most comparable set of inputs, will need to move from using NISE based on SSMIR to NISE_A2 based on AMSR-2. |
| Effective Date for Implementation of Change | The PGE03/CloudMask 6.1.8 and PGE06/L2 Cloud 6.1.12 will go into use 8/6/25 in standard and nrt processing. Recipe information is: AM1M_C61_s1glu 6.1.126 PGE02 6.2.2_118 PGE03 6.1.8 PGE60 6.1.1 PGE85 6.1.4 PGE90 6.1.0_5 PGE92 6.1.1 PGE93 6.1.0 PM1M_C61_s1glu 6.1.129 PGE02 6.2.3_41 PGE03 6.1.8 PGE60 6.1.1 PGE85 6.1.4 PGE90 6.1.0_5 PGE92 6.1.1 PGE93 6.1.0 A/PM1M_C61_A1glu 6.1.63 PGE04 6.1.11 PGE06 6.1.12 PGE83 6.1.0 PGE120A1 6.1.14 NRT variations went into use starting 8/7/25: AM1M_C61_s1nrtglu 6.1.125 PGE02 6.2.2_118 PGE03 6.1.8 PGE128 6.1.8 PGE93 6.1.0 PM1M_C61_s1nrtglu 6.1.132 PGE02 6.2.3_41 PGE03 6.1.8 PGE128 6.1.8 PGE93 6.1.0 A/PM1M_C61_A1nrtglu 6.1.67 PGE04 6.1.11 PGE06 6.1.12 PGE83 6.1.0 PGE120A1 6.1.15 |
| Status | Sadashiva Devadiga approved 07/31/2025. Sudipta Sarkar implemented on 07/31/2025. |
