Grid Resolution: 0.25 degrees lat/lon
Domain: Global

MIRS is based on an assimilation-type scheme (1DVAR), capable of optimally retrieving atmospheric and surface state parameters simultaneously. Thanks to its dynamic memory design, it is capable of performing retrievals using different instrumental configurations. Currently at NOAA/NESDIS/STAR, MIRS is applied routinely to NOAA-18 and METOP-A AMSU/MHS sensors pair and is being extended to run routinely with DMSP-F16 SSMI/S data. It is also expected that MIRS will be the retrieval algorithm for the future sensors: NPP/ATMS and NPOESS microwave sensors (MIS, ATMS). MIRS uses the Community Radiative Transfer Model (CRTM) as its forward operator, leveraging therefore a large amount of effort being undertaken at the Joint Center for Satellite Data Assimilation (JCSDA). The direct outputs from MIRS include temperature, moisture and several hydrometeors atmospheric profiles, land surface temperature and emissivity (at all channels). From these core products are derived a set of secondary products using the Vertical Integration and Post-Processing (VIPP) process. These include: Total Precipitable Water (TPW), vertically integrated Cloud Liquid Water (CLW), Ice Water Path (IWP), Graupel-size ice Water Path (GWP), Rain Water Path (RWP). In addition, surface properties are also derived from the retrieved emissivities and associated skin temperature. These include Snow Water Equivalent (SWE), Sea Ice Concentration (SIC), Soil Wetness Index (SWI) or Soil Moisture. Rainfall rate is also extracted form the RWP and IWP as a final step. The constraints in MiRS are physical relying on CRTM to provide radiances as well as Jacobians of the latter with respect to all geophysical parameters including hydrometeors. The radiometric derivatives are determined using the tangent linear and adjoint methods. Additional constraints are included in MiRS in the form of the covariance matrices which includes off-diagonal correlations between the different parameters. Additional information could be obtained by contacting sid.boukabara@noaa.gov and/or Flavio.Iturbide-Sanchez@noaa.gov.