• Changes in Onset of Vegetation Growth on Svalbard, 2000–2020 

      Karlsen, Stein Rune; Elvebakk, Arve; Tømmervik, Hans; Belda, Santiago; Stendardi, Laura (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-15)
      The global temperature is increasing, and this is affecting the vegetation phenology in many parts of the world. The most prominent changes occur at northern latitudes such as our study area, which is Svalbard, located between 76300N and 80500N. A cloud-free time series of MODIS-NDVI data was processed. The dataset was interpolated to daily data during the 2000–2020 period with a 231.65 m pixel ...
    • Multi-Sensor Analysis of Snow Seasonality and a Preliminary Assessment of SAR Backscatter Sensitivity to Arctic Vegetation: Limits and Capabilities 

      Stendardi, Laura; Karlsen, Stein Rune; Malnes, Eirik; Nilsen, Lennart; Tømmervik, Hans; Cooper, Elisabeth J.; Notarnicola, Claudia (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-13)
      Snow melt timing and the last day of snow cover have a significant impact on vegetation phenology in the Svalbard archipelago. The aim of this study is to assess the seasonal variations of the snow using a multi-sensor approach and to analyze the sensitivity of the Synthetic Aperture Radar (SAR) backscatter to vegetation growth and soil moisture in an arctic environment. A combined approach using ...
    • Time-series of cloud-free sentinel-2 ndvi data used in mapping the onset of growth of central Spitsbergen, Svalbard 

      Karlsen, Stein Rune; Stendardi, Laura; Tømmervik, Hans; Nilsen, Lennart; Arntzen, Ingar; Cooper, Elisabeth J. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-02)
      The Arctic is a region that is expected to experience a high increase in temperature. Changes in the timing of phenological phases, such as the onset of growth (as observed by remote sensing), is a sensitive bio-indicator of climate change. In this paper, the study area was the central part of Spitsbergen, Svalbard, located between 77.28°N and 78.44°N. The goals of this study were: (1) to prepare, ...