Support is requested for the following interdependent activities: 1. Refinement of the level-2 cloud mask (product MOD35 and MYD35 for terra and aqua, respectively) and 1KM cloud-top property (CTP)…

This is a $100,815.45 grant awarded by the National Aeronautics and Space Administration (NASA) Shared Services Center to Texas A&M University. The grant supports three key activities:

1. Refinement of NASA's Level-2 cloud mask, cloud-top property, and cloud optical property datasets from the MODIS sensors on the Terra and Aqua satellites. This includes completing ongoing refinement work and developing a new infrared optimal estimation algorithm to replace the current CO2-slicing heritage algorithm.

2. Further development of algorithms to provide cloud product continuity between the MODIS and VIIRS sensors, including an imager-only algorithm using common spectral channels and a sounder-based approach using AIRS and CRIS data.

3. Continued leadership roles for the principal investigator as the MODIS Atmosphere Team Discipline Lead and the co-investigator as the SNPP Atmosphere Team Discipline Lead, providing coordination between the MODAPS and SIPS processing systems.

This grant does not have a set-aside designation. Texas A&M University is part of the Texas A&M University System, a large state-run higher education system that has received significant federal prime contract and grant funding.

Support is requested for the following interdependent activities: 1. Refinement of the level-2 cloud mask (product MOD35 and MYD35 for terra and aqua, respectively) and 1KM cloud-top property (CTP) and cloud optical property (COP) datasets (MOD06/MYD06). MOD06 provides cloud thermodynamic phase, radiative height, optical thickness, effective particle radius, and water path along with a variety of quality assessment fields and uncertainties. Maintenance-only support was separately proposed for these products as part of the 2017 terra and aqua senior review proposals. Here, proposed efforts include completion of ongoing refinement activities, further development/refinement of an infrared optimal estimation (IROE) algorithm to replace the existing 1KM cloud-top property algorithm (CO2-slicing heritage), and new efforts that arose in trying to achieve product continuity. Maintenance for the 5KM MOD06 cloud-top property algorithm was proposed for the senior review; further refinement is not proposed here. 2. Further development of a suite of algorithms designed to provide level-2 cloud product continuity across terra/aqua and snpp. Direct product continuity between modis and viirs using existing modis algorithms is problematic because of the absence of key spectral channels on viirs and a significant change in the spectral location for a key shortwave infrared band used for microphysical retrievals. A two-pronged approach for achieving product continuity for the core suite of modis cloud products (cloud detection/masking, CTP, COP) was begun by the team under roses-2013 a.29. This included: (a) an imager-only algorithm using only spectral channels common to viirs and modis, based on heritage MOD35 and COP MOD06 algorithms, along with the NOAA algorithm working group (AWG) cloud height algorithm (ACHA). Since the algorithms can be run with similar spectral observations from both viirs and modis, they provide the basis for establishing a continuous cloud data record across the two imagers. Though the initial algorithm details have been finalized, a quantitative assessment of continuity across the imagers has been delayed pending an analysis of viirs VS. Modis shortwave channel relative calibration offsets. The team is now positioned to fully evaluate this common algorithm approach to product continuity and, early in the proposal period, initiate an algorithm theoretical basis document (ATBD) process per solicitation requirements. (B) development of cloud mask and cloud property algorithms using sounder measurements in lieu of higher-spatial resolution modis infrared channels absent on viirs (i.e., merging modis/airs and viirs/cris observations). This effort is undergoing initial testing at the U. Wisconsin science investigator processing system (SIPS). Support for further work is requested in this proposal. Results from this approach will be compared with imager-only and existing modis products before deciding to proceed with the ATBD process and possible production. 3. The proposed effort includes the continued role of the PI as the modis atmosphere team discipline lead and CO-I S. Ackerman as the snpp atmosphere team discipline lead. The dual roles will provide separate but synergistic science coordination for modis adaptive processing system (MODAPS) and SIPS activities. While the solicitation requests proposals for a single consolidated EOS and snpp team lead, the use of multiple leads associated with the atmosphere team's physically separate production systems has been discussed with the solicitation's HQ pocs.