Climatology and summer energy and water balance of polygonal tundra in the Lena River Delta, Siberia

Abstract

[1] Meteorological and soil temperature and moisture data for the period 1998-2005 are presented from a long term monitoring station in the central Lena River Delta at 72°N, 126°E. The investigation site, Samoylov Island, is situated in the zone of continuous permafrost and is characterized by wet polygonal tundra. The summer energy and water balance of the tundra was analyzed for the dry year 1999 and the wet year 2003. The summer water balance of the tundra was found to be mainly controlled by precipitation. The partitioning of the available energy was controlled by precipitation via the soil moisture regime, and by the synoptic weather conditions via radiation and the advection of maritime cold or continental warm air masses. In 2003, regular high precipitation resulted in a constant recharge of polygonal ponds. Of the available energy, 61% were partitioned into latent heat flux and 17% into ground heat flux; hence, the tundra behaved like a typical wetland. In 1999, low precipitation resulted in a loss of polygonal pond waters and a drying of upper soil layers. This led to lower latent heat flux (31% of available energy), higher ground heat flux (29%), and a considerably higher soil thaw depth compared to 2003. Surface and subsurface water flow had a significant influence on the tundra water balance. In 2003, the formation of new surface flow channels through thermo-erosion was observed, which is expected to have a strong and lasting influence on the hydrologic system of the tundra.

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

“…Depending on the type of water supply, tundra ecosystems may therefore experience differential responses to climate variability and climate change Boike et al, 2008). At the wet fen, our observations showed negative water balances during the growing season 2013 but the loss of water through ET was compensated by moisture supply from soil moisture.…”

“…In contrast, the wet fen showed attenuated behaviour of LE, ET, H and G to the variability in snow meltwater as the fen receives its moisture supply mostly from minerotrophic water supply, which remained relatively stable over the 2 study years. Growing season variability in the partitioning of the surface energy balance components was also observed at a polygonal tundra site in Siberia (Boike et al, 2008). However, the observed differences were mainly driven by variability in summertime precipitation.…”

The surface energy balance of a polygonal tundra site in northern Siberia – Part 1: Spring to fall

“…More detailed descriptions of the vegetation and landscape characteristics are available; cf. Are and Reimnitz (2000), Kutzbach et al (2004Kutzbach et al ( , 2007, Boike et al (2008) and Sachs et al (2008).…”

“…However, Siberian sites are not included and generally few published studies are available for the Siberian tundra (Kodama et al, 2007;Boike et al, 2008).…”

Methanogenesis in Arctic Permafrost Habitats

“…As a result of cryopedogenesis, many permafrost soils are influenced by a strong micro-relief (e.g. low-centered ice-wedge polygons), which causes small-scale variations in soil types and vegetation characteristics (Kutzbach et al 2004), as well as in the microclimatic conditions (Boike et al 2008). This affects the abundance, processes and diversity of the methanogenic community in this habitat.…”