A numerical testbed for remote sensing of aerosols, and its demonstration for evaluating retrieval synergy from a geostationary satellite constellation of GEO-CAPE and GOES-R

Abstract

Michael I., "A numerical testbed for remote sensing of aerosols, and its demonstration for evaluating retrieval synergy from a geostationary satellite constellation of GEO-CAPE and GOES-R" (2014 a b s t r a c tWe present a numerical testbed for remote sensing of aerosols, together with a demonstration for evaluating retrieval synergy from a geostationary satellite constellation. The testbed combines inverse (optimal-estimation) software with a forward model containing linearized code for computing particle scattering (for both spherical and non-spherical particles), a kernel-based (land and ocean) surface bi-directional reflectance facility, and a linearized radiative transfer model for polarized radiance. Calculation of gas absorption spectra uses the HITRAN (HIgh-resolution TRANsmission molecular absorption) database of spectroscopic line parameters and other trace species cross-sections. The outputs of the testbed include not only the Stokes 4-vector elements and their sensitivities (Jacobians) with respect to the aerosol single scattering and physical parameters (such as size and shape parameters, refractive index, and plume height), but also DFS (Degree of Freedom for Signal) values for retrieval of these parameters. This testbed can be used as a tool to provide an objective assessment of aerosol information content that can be retrieved for any constellation of (planned or real) satellite sensors and for any combination of algorithm design factors (in terms of wavelengths, viewing angles, radiance and/or polarization to be measured or used). We summarize the components of the testbed, including the derivation and validation of analytical formulae for Jacobian calculations. Benchmark calculations from the forward model are documented. In the context of NASA's Decadal Survey Mission GEO-CAPE (GEOstationary Coastal and Air Pollution Events), we demonstrate the use of the testbed to conduct a feasibility study of using polarization measurements in and around the O 2 A band for the retrieval of aerosol height information from space, as well as an to assess potential improvement in the retrieval of aerosol fine and coarse mode aerosol optical depth (AOD) through the synergic use of two future geostationary satellites, GOES-R (Geostationary Operational Environmental Satellite R-series) and TEMPO (Tropospheric Emissions: Monitoring of Pollution). Strong synergy between GEOS-R and TEMPO are found especially in their characterization of surface bi-directional reflectance, and thereby, can potentially improve the AOD retrieval to the accuracy required by GEO-CAPE.

Potential application of VIIRS Day/Night Band for monitoring nighttime surface PM 2.5 air quality from space

“…Hence, I 0 is not exactly equal to the intensity of light at the ground and is a result of multiple scattering and reflection of lights between air and buildings within the surface layer. I 0 is expected to be strongest in places with intense lights at Wang et al, (2014)) for the standard mid-latitude summer atmospehric profile. Aerosol properties are based on Dubovik et al, (2002) for urban aerosols.…”

“…First, a radiative transfer model that can account for the atmospheric transfer of both moonlight and surface-leaving visible light simultaneously is highly needed. Construction of such a model appears technically feasible, because (a) the code and database for a moonlight source function has been compiled by Miller and Turner (2009) and (b) several radiative transfer models, under the framework of discrete coordinate for a multi-layered plane-parallel medium, have been developed recently to account for surfaceleaving radiances (especially those water-leaving radiances for ocean color retrievals, Spurr, 2006;Wang et al, 2014).…”

Evaluation of Aerosol Optical Depth and Aerosol Models from VIIRS Retrieval Algorithms over North China Plain

“…We compute the SSA for all aerosol modes at 440 nm in the VIIRS_EDR by inputting the aerosol parameters (refractive indices, size parameters and volume concentrations of each mode) into Mie scattering calculation [36]. The reason for using 440 nm is that the aerosol model properties in the VIIRS_EDR algorithm are mostly referred at 440 nm [6].…”

Tropospheric emissions: monitoring of pollution (TEMPO)

“…TEMPO may be used together with the Advanced Baseline Imager (ABI) instruments on the NOAA GOES-R and GOES-S satellites for aerosol retrievals ( [119]. The ABI will image in 16 different spectral bands including 0.64 μm at 0.5 km spatial resolutions and at 0.47 μm, 0.87 μm and 1.6 μm at 1 km resolution [92].…”