PACE SPEXone Level-2 Regional Aerosol Over Ocean Optical Properties, FastMAPOL Algorithm Data, version 3.0

MAPOL_OCEAN provides simultaneous aerosol and ocean color products using the Fast Multi-Angle Polarimetric Ocean and Land algorithm (FastMAPOL). The retrievals jointly solve for aerosol and ocean parameters with a coupled atmosphere and ocean vector radiative-transfer model, accelerated by deep neural networks to improve speed and accuracy. The retrieved aerosol properties are then used to derive angular water leaving signals through multi-angle atmospheric corrections. Use these products for advanced aerosol and ocean color studies, cross-sensor and cross-algorithm data product analysis.

Core geophysical variables in this suite include:
- Rrs1/Rrs2 — Angular remote sensing reflectance before and after BRDF correction (sr⁻¹)
- chla_mapol — Chlorophyll-a concentration (mg m⁻³)
- aot / aot_fine / aot_coarse — Aerosol optical thickness for total/fine/coarse mode (unitless)
- ssa / ssa_fine / ssa_coarse — Aerosol single scattering albedo for total/fine/coarse mode (unitless)
- fmf / fvf — Aerosol fine mode fraction and fine mode volume fraction (unitless)
- angstrom — Aerosol Ångström exponent (unitless; reported for 440–670 nm and 440–870 nm)
- alh — Aerosol layer height (km)
- reff_fine / reff_coarse — Aerosol effective radius for fine/coarse mode (µm)
- veff_fine / veff_coarse — Aerosol effective variance for fine/coarse mode (unitless)
- sph / sph_fine / sph_coarse — Aerosol spherical fraction for total/fine/coarse mode (unitless)
- mr / mi — Real and imaginary parts of aerosol refractive index (unitless; total/fine/coarse modes available)
- vd — Aerosol volume density (µm³ µm⁻²; fine/coarse modes and submodes also available)
- wind_speed — Ocean surface wind speed (m s⁻¹)