Assessing the Potential Benefits of the Geostationary Vantage Point for Generating Daily Chlorophyll-a Maps in the Baltic Sea
|Author(s)||Bellacicco Marco1, Ciani Daniele2, Doxaran David1, Vellucci Vincenzo1, Antoine David1, 3, Wang Menghua4, D'Ortenzio Fabrizio1, Marullo Salvatore5|
|Affiliation(s)||1 : Sorbonne Univ, CNRS, LOV, F-06230 Villefranche Sur Mer, France.
2 : CNR, Inst Marine Sci ISMAR, I-00133 Rome, Italy.
3 : Curtin Univ, Sch Earth & Planetary Sci, Remote Sensing & Satellite Res Grp, Perth, WA 6845, Australia.
4 : NOAA, NESDIS Ctr Satellite Applicat & Res, College Pk, MD 20740 USA.
5 : Italian Natl Agcy New Technol Energy & Sustainabl, I-00044 Frascati, Italy.
|Source||Remote Sensing (2072-4292) (Mdpi), 2018-12 , Vol. 10 , N. 12https:// , P. 1944 (12p.)|
|Note||Special Issue Remote Sensing of Short-Term Coastal Ocean Processes Enabled from Geostationary Vantage Point)|
|Keyword(s)||remote sensing, ocean color products, geostationary sensor, Baltic Sea|
Currently, observations from low-Earth orbit (LEO) ocean color sensors represent one of the most used tools to study surface optical and biogeochemical properties of the ocean. LEO observations are available at daily temporal resolution, and are often combined into weekly, monthly, seasonal, and annual averages in order to obtain sufficient spatial coverage. Indeed, daily satellite maps of the main oceanic variables (e.g., surface phytoplankton chlorophyll-a) generally have many data gaps, mainly due to clouds, which can be filled using either Optimal Interpolation or the Empirical Orthogonal Functions approach. Such interpolations, however, may introduce large uncertainties in the final product. Here, our goal is to quantify the potential benefits of having high-temporal resolution observations from a geostationary (GEO) ocean color sensor to reduce interpolation errors in the reconstructed hourly and daily chlorophyll-a products. To this aim, we used modeled chlorophyll-a fields from the Copernicus Marine Environment Monitoring Service's (CMEMS) Baltic Monitoring and Forecasting Centre (BAL MFC) and satellite cloud observations from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) sensor (on board the geostationary satellite METEOSAT). The sampling of a GEO was thus simulated by combining the hourly chlorophyll fields and clouds masks, then hourly and daily chlorophyll-a products were generated after interpolation from neighboring valid data using the Multi-Channel Singular Spectral Analysis (M-SSA). Two cases are discussed: (i) A reconstruction based on the typical sampling of a LEO and, (ii) a simulation of a GEO sampling with hourly observations. The results show that the root mean square and interpolation bias errors are significantly reduced using hourly observations.