A satellite-measured view of aerosol component content and optical property in a haze-polluted case over North China Plain
Abstract
The Directional Polarimetric Camera (DPC) is the first Chinese satellite-borne multi-angle polarimetric sensor onboard the GaoFen-5 (GF-5) satellite, which was launched on May 9th 2018. In this paper, we present the spatiotemporal variability of satellite-measured aerosol components (such as, black carbon, brown carbon, iron oxides contained in mineral dust etc.) over North China Plain (36-41°N, 113-123°E) for a heavily haze-polluted case, to demonstrate the first successful retrievals of aerosol component content and optical property directly from the DPC/GF-5 instrument measurements. We also reveal the relationship between absorbing/scattering component mass ratio and aerosol absorption based on the multi-angle polarimetric satellite measurements, which presents comparable agreement with previous laboratory studies and field studies for an indirect validation of aerosol component retrievals. In addition, the feasibility, stability and uncertainty of the aerosol optical property and component content retrievals from DPC multi-angle polarimetric observations were evaluated and assessed by sensitivity tests. The distributions of DPC/GF-5 aerosol optical depth (AOD) are in line with satellite-observed MODIS (Moderate-resolution Imaging Spectroradiometer) AOD and ground-based CARSNET (China Aerosol Remote Sensing Network) AOD products. Therefore, the multi-angle polarimetric satellite measurements show an encouraging potential for the comprehensive inversion of aerosol optical, microphysical and chemical properties. The results and further applications of this component algorithm in the future are helpful to reduce the uncertainty of climate change assessment by providing the measurements of aerosol component, in particular for black carbon, brown carbon, and iron oxides contained in dust, with large and extensive spatiotemporal scale.