Transcript Slide 1
Climate change in the arctic and the impact on marine ecosystems Door: Anja Jansen Begeleiding: Wim Klaassen (NASA) 2004/’05 Increased warming at the poles Research question What are the influences of climate change on the arctic region and its marine ecosystem? Topics Climate change Melting of ice Sea current changes Ecosystem changes The arctic climate The climate of the arctic is distinguished by its most important quality: cold. Why is the arctic cold? - the sunlight has to travel a long way through the atmosphere - high albedo of the arctic region - energy lost by warmth transport in water and melting of ice (in summer) Temperature change in the arctic Changes in surface temperature between the periods 1981-1992 and 19922003 (Comiso en Parkinson, 2004) The Arctic oscillation Arctic oscillation Positive phase Negative phase The arctic oscillation seems to be staying in the positive, warm phase (NOAA) Ozone concentration in march 1979 (left) and march 2003 (right). (NASA) Temperature change in the troposphere (left) and the stratosphere (right) between the 80’s and the 90’s of the twentieth century. (Overland, Wang en Bond, 2002) polar vortex polar statospheric clouds Trends in september sea ice concentration between 1979-1996 (a) and 1979-2002 (b) (NASA) The expected loss of summer sea ice in this century. (ACIA report, 2004) Changes in ice coverage on greenland Source: Corell (2004). Graph of annual average temperature and average total precipitation for 1897 to 1998. Based on data for the Cascade West Climate Division. The red lines show the general trend of both temperature and precipitation, while the blue dots show the annual variation of both values. Annual runoff of Lena, Ob and Yenisey Rivers. The Ob and Yenisey Rivers show an increase since the 1980s Seacurrent change Slowing and possible disappearing Gulf Stream in the north atlantic Important changes Warming Melting of sea-ice River runoff Stratification Slowing Gulf Stream Stronger light Average frostless period and the trend between 1988 and 2001 Changes of primary production between the periods 1997-2002 and 1979-1986 Changes in sea-ice, permafrost area and tree line expected by the end of the century (ACIA) ACIA ACIA Changes in water temperature and in fish numbers observed in pacific fish harvests (Klyashtorn and Smirnov) Red line = herring Blue line = temperature ACIA Influences on the ecosystem Ozone depletion & sea-ice loss : - Reactions with sunlight -> toxic chemicals (hydroxyl, peroxide, super-oxide, etc) - UV-B harmful for phytoplankton - DNA damage in bacteria and larvae - Fish get UV-B sunburns Conclusions The climate of the earth is a fragile equilibrium which has been changed very often in the earth’s history. Climate change forces species to adept or extinct, and helps new species to evolve, by creating new habitat. There have been many drastic changes in the arctic environment, and to fully understand the consequences on the ecosystem needs a lot more research.