Two years with extreme and little snowfall: effects on energy partitioning and surface energy exchange in a high-Arctic tundra ecosystem

Abstract

Abstract. Snow cover is one of the key factors controlling Arctic ecosystem functioning and productivity. In this study we assess the impact of strong variability in snow accumulation during 2 subsequent years (2013-2014) on the landatmosphere interactions and surface energy exchange in two high-Arctic tundra ecosystems (wet fen and dry heath) in Zackenberg, Northeast Greenland. We observed that recordlow snow cover during the winter 2012/2013 resulted in a strong response of the heath ecosystem towards low evaporative capacity and substantial surface heat loss by sensible heat fluxes (H ) during the subsequent snowmelt period and growing season. Above-average snow accumulation during the winter 2013/2014 promoted summertime ground heat fluxes (G) and latent heat fluxes (LE) at the cost of H . At the fen ecosystem a more muted response of LE, H and G was observed in response to the variability in snow accumulation. Overall, the differences in flux partitioning and in the length of the snowmelt periods and growing seasons during the 2 years had a strong impact on the total accumulation of the surface energy balance components. We suggest that in a changing climate with higher temperature and more precipitation the surface energy balance of this high-Arctic tundra ecosystem may experience a further increase in the variability of energy accumulation, partitioning and redistribution.

Snow cover variability at Polar Bear Pass, Nunavut

“…Variable snowpack accumulation and melt patterns across years have influenced atmospheric-land interactions by modifying surface energy partitioning over diverse tundra ecosystems (both wet and dry) (Stiegler et al 2016). Field and modeling efforts by Domine et al (2016aDomine et al ( , 2016b showed that changes in tundra shrub growth in the High Arctic can impact snow and thermal properties, ultimately leading to ground warming and permafrost loss.…”

Land–Atmosphere Exchange of Water and Heat in the Arid Mountainous Grasslands of Central Asia during the Growing Season

“…Solar radiation is Earth's main source of energy as well as the basic driving force of physical and biological processes on its surface, and when solar radiation reaches the land surface through the atmosphere, the energy is redistributed in multiple ways. The net radiation received by the land surface is mainly transferred via moisture and heat to the atmosphere in the form of latent and sensible heat, whereas another portion is transduced into the soil or stored in the plant canopy [10,11]. Radiant energy is influenced by different geographic features and other factors, and the amount of this energy received by different terrestrial ecosystems varies [12].…”

Spatiotemporal variability in surface energy balance across tundra, snow and ice in Greenland

“…A thin snow cover, e.g. at APO-M during early 2013 (maximum snow depths <0.2 m) with ice partly exposed in the immediate surroundings of the weather station, may result in lower albedo and higher net shortwave radiation compared with completely snow-covered surfaces (Stiegler et al 2016).

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“…The energy balance closure during the study period was on average 85, 81 and 83% for ZAC-H, ZAC-F and KOB-F, respectively. More information on the eddy covariance systems, processing and uncertainties is provided by Lund et al (2012, 2014) and Stiegler et al (2016). Heat stored above the soil heat flux plates was calculated according to Lund et al (2014) and added to the measured flux.…”