Satellite-aided studies of vegetation cover, biomass and productivity are becoming increasingly important for monitoring the effects of a changing climate on the biosphere. With their large spatial coverage and good temporal resolution, space-borne instruments are ideal to observe remote areas over extended time periods. However, long time series datasets with global coverage have in many cases too low spatial resolution for sparsely vegetated high latitude areas. This study has made use of a newly developed 30 year 1 km spatial resolution dataset from 1986 to 2015, provided by the NOAA AVHRR series of satellites, in order to calculate the annual maximum NDVI over parts of Svalbard (78°N). This parameter is indicative of vegetation productivity and has therefore enabled us to study long-term changes in greening within the Inner Fjord Zone on Svalbard. In addition, local meteorological data are available to link maximum NDVI values to the temporal behavior of the mean growing season (summer) temperature for the study area. Over the 30 year period, we find positive trends in both maximum NDVI (average increase of 29%) and mean summer temperature (59%), which were significantly positively correlated with each other. This suggests a temporal greening trend mediated by summer warming. However, as also recently reported for lower latitudes, the strength of the year-to-year correlation between maximum NDVI and mean summer temperature decreased, suggesting that the response of vegetation to summer warming has not remained the same over the entire study period.
Norut, P O Box 6434, NO-9294 Tromsø, Norway;Norut, P O Box 6434, NO-9294 Tromsø, Norway;Norut, P O Box 6434, NO-9294 Tromsø, Norway;Norut, P O Box 6434, NO-9294 Tromsø, Norway;Norwegian Institute for Nature Research—NINA, FRAM—High North Centre for Climate and the Environment, PO Box 6606 Langnes, NO-9296 Tromsø, Norway;Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø, Norway;Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway;Norwegian Environment Agency, NO-7485 Trondheim, Norway;Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
Recommended Citation:
Hannah Vickers,Kjell Arild Høgda,Stian Solbø,et al. Changes in greening in the high Arctic: insights from a 30 year AVHRR max NDVI dataset for Svalbard[J]. Environmental Research Letters,2016-01-01,11(10)