Abstract
Atmospheric effects, especially aerosols, are a significant source of uncertainty for optical remote sensing of surface parameters, such as albedo. Also to achieve a homogeneous surface albedo time series, the atmospheric correction has to be homogeneous. However, a global homogeneous aerosol optical depth (AOD) time series covering several decades did not previously exist. Therefore, we have constructed an AOD time series 1982–2014 using aerosol index (AI) data from the satellite measurements of the Total Ozone Mapping Spectrometer (TOMS) and the Ozone Monitoring Instrument (OMI), together with the Solar zenith angle and land use classification data. It is used as input for the Simplified Method for Atmospheric Correction (SMAC) algorithm when processing the surface albedo time series CLARA-A2 SAL (the Surface ALbedo from the Satellite Application Facility on Climate Monitoring project cLoud, Albedo and RAdiation data record, the second release). The surface reflectance simulations using the SMAC algorithm for different sets of satellite-based AOD data show that the aerosol-effect correction using the constructed TOMS/OMI based AOD data is comparable to using other satellite-based AOD data available for a shorter time range. Moreover, using the constructed TOMS/OMI based AOD as input for the atmospheric correction typically produces surface reflectance [-20]values closer to those obtained using in situ AOD values than when using other satellite-based AOD data.
Highlights
The surface albedo, defined as the fraction of incoming radiation reflected hemispherically by the surface, is an essential climate variable (ECV) and directly related to the surface radiation budget [1]
Using the constructed Total Ozone Mapping Spectrometer (TOMS)/Ozone Monitoring Instrument (OMI) based aerosol optical depth (AOD) as input for the atmospheric correction typically produces surface reflectance values closer to those obtained using in situ AOD values than when using other satellite-based AOD data
In order to test the quality of the τAI data, it was compared to three satellite-based AOD data sets: MODerate resolution Imaging Spectroradiometer (MODIS), Sea-Viewing Wide Field-of-view Sensor (SeaWiFS) and Multi-angle Imaging SpectroRadiometer (MISR) (Table 1)
Summary
The surface albedo, defined as the fraction of incoming radiation reflected hemispherically by the surface, is an essential climate variable (ECV) and directly related to the surface radiation budget [1]. Some attempts to construct the AOD information in the UltraViolet (UV) range from aerosol index (AI) data have been made [3,4], but there are no daily AOD data in the visible channel for the whole needed time period. The atmospheric correction based on the constructed AOD data should be close to the results produced applying the SMAC algorithm to other satellite-based or in situ AOD values.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
