Time-Series of Cloud-Free Sentinel-2 NDVI Data Used in Mapping the Onset of Growth of Central Spitsbergen, Svalbard

Remote Sensing

Laura Stendardi¹  Lennart Nilsen²  Elisabeth J. Cooper²  Ingar Arntzen³  Stein Rune Karlsen³  Hans Tømmervik⁴ 

[1] Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Piazzale delle Cascine, 18-50144 Firenze, Italy;Department of Arctic and Marine Biology, UiT—The Arctic University of Norway, 9037 Tromsø, Norway;NORCE Norwegian Research Centre AS, P.O. Box 6434, 9294 Tromsø, Norway;Norwegian Institute for Nature Research (NINA), FRAM—High North Research Centre for Climate and the Environment, P.O. Box 6606, Langnes, 9296 Tromsø, Norway;

关键词: Sentinel-2;    NDVI;    time-series;    onset of growth;    Svalbard;   

DOI  :  10.3390/rs13153031

来源: DOAJ

【 摘 要 】

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, analyze and present a cloud-free time-series of daily Sentinel-2 NDVI datasets for the 2016 to 2019 seasons, and (2) to demonstrate the use of the dataset in mapping the onset of growth. Due to a short and intense period with greening-up and frequent cloud cover, all the cloud-free Sentinel-2 data were used. The onset of growth was then mapped by a NDVI threshold method, which showed significant correlation (r² = 0.47, n = 38, p < 0.0001) with ground-based phenocam observation of the onset of growth in seven vegetation types. However, large bias was found between the Sentinel-2 NDVI-based mapped onset of growth and the phenocam-based onset of growth in a moss tundra, which indicates that the data in these vegetation types must be interpreted with care. In 2018, the onset of growth was about 10 days earlier compared to 2017.

【 授权许可】

Unknown