Characteristics of summer-time energy exchange in a high Arctic tundra heath 2000-2010

Research output: Contribution to journalArticle

Abstract

Global warming will bring about changes in surface energy balance of Arctic ecosystems, which will have implications for ecosystem structure and functioning, as well as for climate system feedback mechanisms. In this study, we present a unique, long-term (2000-2010) record of summer-time energy balance components (net radiation, R-n; sensible heat flux, H; latent heat flux, LE; and soil heat flux, G) from a high Arctic tundra heath in Zackenberg, Northeast Greenland. This area has been subjected to strong summer-time warming with increasing active layer depths (ALD) during the last decades. We observe high energy partitioning into H, low partitioning into LE and high Bowen ratio (beta = H/LE) compared with other Arctic sites, associated with local climatic conditions dominated by onshore winds, slender vegetation with low transpiration activity and relatively dry soils. Surface saturation vapour pressure deficit (D-s) was found to be an important variable controlling within-year surface energy partitioning. Throughout the study period, we observe increasing H/R-n and LE/R-n and decreasing G/R-n and beta, related to increasing ALD and decreasing soil wetness. Thus, changes in summer-time surface energy balance partitioning in Arctic ecosystems may be of importance for the climate system.

Details

Authors
  • Magnus Lund
  • Birger U. Hansen
  • Stine H. Pedersen
  • Christian Stiegler
  • Mikkel P. Tamstorf
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Geography

Keywords

  • energy budget, energy balance, Arctic, sensible heat, latent heat, ground heat, net radiation, climate change, global warming
Original languageEnglish
Article number21631
JournalTellus. Series B: Chemical and Physical Meteorology
Volume66
Publication statusPublished - 2014
Publication categoryResearch
Peer-reviewedYes