Temperature, water level and bathymetry of thermokarst lakes in the continuous permafrost zone of northern Siberia - Lena River Delta, Siberia ...

• Main Authors: Boike, Julia, Georgi, C, Kirilin, G, Muster, Sina, Abramova, Katya, Fedorova, Irina V, Chetverova, Antonina, Grigoriev, Mikhail N, Bornemann, Niko, Langer, Moritz
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2015
• Subjects: air temperature; Arctic Tundra; atmospheric radiation; Bathymetry; humidity; Lake/Pond; river delta; water temperature; wind speed; Changing Permafrost in the Arctic and its Global Effects in the 21st Century PAGE21; Arctic; Ice; lena river; permafrost; Thermokarst; Tundra; Siberia
• Online Access: https://dx.doi.org/10.1594/pangaea.846525; https://doi.pangaea.de/10.1594/PANGAEA.846525

Thermokarst lakes are typical features of the northern permafrost ecosystems, and play an important role in the thermal exchange between atmosphere and subsurface. The objective of this study is to describe the main thermal processes of the lakes and to quantify the heat exchange with the underlying sediments. The thermal regimes of five lakes located within the continuous permafrost zone of northern Siberia (Lena River Delta) were investigated using hourly water temperature and water level records covering a 3-year period (2009-2012), together with bathymetric survey data. The lakes included thermokarst lakes located on Holocene river terraces that may be connected to Lena River water during spring flooding, and a thermokarst lake located on deposits of the Pleistocene Ice Complex. Lakes were covered by ice up to 2 m thick that persisted for more than 7 months of the year, from October until about mid-June. Lake-bottom temperatures increased at the start of the ice-covered period due to upward-directed heat ... : In July 2009, water level and temperature sensors (HOBO Temp Pro v2, HOBO U20, Onset, ± 0.2°C across a temperature range from 0 °C to 70 °C, and ± 0.4°C across a temperature range from -40 °C to 0 °C) were installed within the water columns of the investigated lakes on Samoylov and Kurungnakh Island. Figure 1 shows the locations of the lakes (labelled Sa_Lake_1-4 for Samoylov and Ku_Lake_1 for Kurungnakh) and the location of the long term weather station. Gaps in the climate data record (air temperature, radiation, humidity, wind speed and direction, and snow depth) were filled whenever possible with data from temporary climate and eddy covariance stations located in close proximity to the weather station (Boike et al., 2013). Temperature and water depth sensors were placed directly above the sediment-water interface and then temperature sensors at 2 m intervals up to 2 m below the water surface (Figure 2). The sensors were suspended in the water column from a buoy and anchored in the sediment below. The ...