Aleksey Malinka
National Academy of Sciences of Belarus
Belarus
Title: Retrieval of the sea ice optical properties from satellite optical measurements
Biography
Biography: Aleksey Malinka
Abstract
Satellite remote sensing is an important tool for monitoring the sea ice state, particularly in the difficult-to-access Polar Regions. The snow grain size, the soot contaminants concentration, the melt pond fraction (during the summer melt), and the surface albedo are the key characteristics for various problems regarding the climate changes, monitoring the ice melt process, particularly regarding the drastic changes in the Arctic environment, observed in the recent years. The common approach to retrieve the sea ice characteristics uses the a priori reflection spectra of the sea ice surface components: snow, white ice, blue ice, melt pond, and so on. Here another technique is presented based on models of the optical properties of sea ice. Algorithm MPD (Melt Pond Detector) considers the summer ice as consisting of white ice (high reflective) and melt ponds. The MPD input is the MERIS data. The algorithm retrieves the surface characteristics in an iterative procedure with the Newton-Raphson method. It uses the simple optical model of ice, take into account the bidirectional reflection, and include the atmospheric correction. It was verified with the in situ measurements. The output is maps of the melt pond fraction and the pixel spectral albedo. The produced maps allow monitoring the long-time global changes of the Arctic ice state. These retrievals provide the historical data on the process of Arctic ice melting, which is so important for understanding the climate changes in the Arctic. It is planned to implement it for processing the data of the OLCI on Sentinel-3. Parts of these studies have been supported by the 6th and 7th Framework Programmes of the EU (projects DAMOCLES and SIDARUS).