Ongoing climate-driven changes to the Arctic sea-ice could have a significant impact on the blooming of tiny planktonic plants (phytoplankton) with important implications for the Arctic ecosystem, according to new research conducted by scientists at the UK's National Oceanography Centre (NOC).
"Ice-edge phytoplankton blooms in the Arctic Ocean provide food for planktonic animals called zooplankton, which are in turn exploited by animals higher up the food chain such as fish," explained Dr Andrew Yool, one of the team of NOC researchers.
During the Arctic spring and summer, sea-ice melts and breaks up. Freshwater from melting ice forms a blanket over the denser, saltier water below. This stratification of the water column, along with seasonal sunshine, triggers the appearance of phytoplankton blooms, which often form long but narrow (20-100 km) bands along the receding ice-edge.
Arctic ice-edge blooms have in the past been studied largely during research cruises. These studies have often focused on regions such as the Barents Sea between Norway and the Svalbard Archipelago, and the Bering Shelf bordering Alaska, where blooms are thought to account for 50% or more of biological production.
However, advances in modern satellite technology now offer the opportunity to observe and monitor ice-edge blooms at high spatial resolution over large areas and extended periods of time from space.
"Our aim was to use satellite data to get a synoptic view of ice-edge blooms across the whole Arctic region," said Dr Yool.
To do this, the research team used daily data from the NASA's SeaWiFs satellite, which was launched in 1997. SeaWiFs continuously observes ocean colour (sea-ice, cloud and fog cover permitting), sampling the whole globe every two days. To provide an alternative estimate of bloom occurrence, and an independent check on their findings, the researchers also used data from the MODIS satellite.<
|Contact: Dr. Rory Howlett|
National Oceanography Centre, Southampton (UK)