Spectral studies of ocean water with space-borne sensor SCIAMACHY using Differential Optical Absorption Spectroscopy (DOAS)

[摘要] Methods enabling the retrieval ofoceanic parameter from thespace borneinstrumentation ScanningImaging Absorption SpectrometerforAtmospheric ChartographY (SCIAMACHY)using DifferentialOpticalAbsorption Spectroscopy (DOAS) are presented. SCIAMACHYonboardENVISAT measures back scatteredsolar radiation ata spectralresolution(0.2 to 1.5 nm).The DOAS methodwas used for the firsttime to fit modelled Vibrational Raman Scattering (VRS) in liquidwater and in situmeasured phytoplankton absorption reference spectrato opticaldepths measured by SCIAMACHY. Spectral structures of VRSand phytoplankton absorptionwere clearly foundintheseopticaldepths.Bothfittingapproachesleadtoconsistentresults. DOAS fitscorrelate withestimatesofchlorophyllconcentrations: low fit factors for VRS retrievals correspond to largechlorophyll concentrations andvice versa; large fit factorsforphytoplanktonabsorption correspondwith highchlorophyllconcentrations and viceversa. Fromtheseresults a simpleretrieval technique takingadvantageofboth measurements is shown.First maps of global chlorophyll concentrations were compared to thecorresponding MODIS measurements with very promising results.In addition,results from thisstudywill be used to improve atmospheric trace gas DOAS-retrievals fromvisible wavelengths by including these oceanographic signatures.

[学科分类] 海洋学与技术