Bremen 2017 – wissenschaftliches Programm

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UP: Fachverband Umweltphysik

UP 3: Kryosphäre

UP 3.10: Vortrag

Dienstag, 14. März 2017, 15:00–15:15, GW2 B3009

Cloud screening over sea ice and snow for MERIS/OLCI data — •Larysa Istomina, Henrik Marks, and Georg Heygster — Institute of Environmental Physics, University of Bremen, Bremen, Germany

An accurate cloud screening over snow/ice is important for many remote sensing applications such as satellite retrievals concerning atmospheric parameters or snow and sea ice properties. As optical properties of sea ice/snow and clouds are alike, an accurate cloud screening in the Arctic is a challenging task. Some satellite sensors are better equipped for this task, e.g. with a set of thermal infrared bands. However, they may be not suited for certain retrieval methods due to various other limitations. That is why it is important to develop quality cloud masks also for sensors which are not specifically designed for the task.

In this work, we present a cloud mask developed specifically for retrievals over bright snow and sea ice surfaces from MERIS/OLCI data. The presented dataset consists of pixelwise cloud probability for each available MERIS/OLCI swath. The newly developed cloud screening procedure utilizes data from MERIS/OLCI oxygen A band as well as synergy with SLTSR/AATSR in order to benefit from their infrared bands. The method is able to correctly classify over 90% of the sea ice observations from MERIS during the period May to September if compared to a high-quality cloud mask derived from AATSR.