THE IMPACT OF THE NORTH ATLANTIC OSCILLATION ON VEGETATION DYNAMICS OVER EUROPE

• Main Authors: Célia Gouveia, Ricardo M. Trigo, Carlos Dacamara
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.563.3415

Over the last two decades, the continuous monitoring of vegetation from space has prompted new studies aiming to relate the observed major changes in vegetation (e.g. variability, trends and extremes) with changes of surface climatic variables, such as temperature, precipitation and snow cover. In particular, several groups have shown that the observed rise of temperature in the northern latitudes by 0.8 ºC in the last 25 years is linked to a longer active growing season as a consequence of an early spring and delayed autumn. The change has been shown to be associated with an increase on photosynthetic activity of vegetation as detected from observed trends in the Normalised Difference Vegetation Index (NDVI). Although no evidence has been given that the observed changes in NDVI are related to the recorded increase in atmospheric concentration of CO2 they have undoubtly affected the global carbon cycle and point out the strong need for long-term and large-scale studies aiming to assess the impact of atmospheric circulation variability on both surface climate and vegetation activity. We will assess the relationship of vegetation activity over the European region with the North Atlantic Oscillation (NAO), which is one of the major patterns of atmospheric variability in the Northern Hemisphere. For this purpose we will rely on monthly NDVI and Brightness Temperature