A spaceborne assessment of the Barents Sea phytoplankton biomass vulnerability to cyclone impacts: assessment for 2003-2013

Lead Author Dmitry, Pozdnyakov
Institution Contact Scientific Foundation "Nansen International Environmental and Remote Sensing Centre" Office 49; 7, 14th Line, V. O. 199034, St. Petersburg, Russia Phone: +7-812-324-51-03
Co-Authors Evgeny Morozov, Nansen-Centre, St. Petersburg, Russia Lingzis Tang, China Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China Lasse Pettersson, Nansen-Centre, Bergen, Norway Hartmut Grassl, Max-Planck Meteorological Institute, Hamburg, Germany
Theme Theme 1: Vulnerability of Arctic Environments
Session Name 1.4 Vulnerability of Arctic Communities to Natural Disasters
Datetime Wed, Sep 14, 2016 04:30 PM - 04:45 PM
Presentation Type Oral
Abstract text A pilot satellite-based investigation of modulations exerted upon mixed-layer phytoplankton fields by cyclones was performed for the first time across a selected part of the Arctic Ocean, the Barents Sea (BS). Resorting to a synergistic approach, cyclones were first identified from NCEP/NCАR data for the summer period during 2003–2013, and their propagation throughout the BS was further surveyed. The above-water wind force was retrieved from QuikSCAT data. These data were further accompanied by ocean colour data from SeaWiFS and MODIS to examine the spatial and temporal distributions of surficial phytoplankton chlorophyll concentration (chl) dynamics along the trajectory of the cyclone’s footprint across the sea. Sea surface temperature was retrieved from MODIS data.
The spaceborne data obtained over more than a decade indicate that, on balance, the cyclone passage led to increase in chl within the cyclone footprint area. On average, this increase did not exceed 1–2 μg l–1, which is nevertheless appreciable given that the mean chl within the cyclone footprint rarely exceeded 1μg l–1. Specific mechanisms of the chl enhancements in the BS are revealed and proved.
However, given that (i) the annual number of cyclones capable to produce the above impact is low (2-3), (ii) the cyclone footprint area generally accounting only for about 14% of the BS area, (iii) short duration of chl enhancement (between a few days and a fortnight), the cyclones studied are hardly capable of boosting annual primary productivity in the BS. Moreover, it can be conjectured that the same conclusion can be drawn with respect to the pelagic Arctic tracts that are generally less productive and more extensively cloud-covered than the BS.
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