Modeling of permafrost temperatures in the Lena River Delta, Siberia, based on remote sensing products

• Main Authors: Peter, Maria, Langer, Moritz, Boike, Julia, Westermann, Sebastian, Schwamborn, Georg, Etzelmüller, Bernd
• Format: Conference Object
• Language: unknown
• Published: 2014
• Subjects: Ice; lena river; permafrost; Siberia
• Online Access: https://epic.awi.de/id/eprint/35903/; https://hdl.handle.net/10013/epic.43821

Permafrost soils of the climatically sensitive region of the northeast Siberian lowlands contain large amounts of carbon, but monitoring the thermal ground conditions and predicting its future is challenging for such vast areas. Recently, a permafrost modeling scheme based on remote sensing data has been demonstrated for the Samoylov Island permafrost observatory (Langer et al. 2013). This scheme was extended to the entire Lena River Delta, using the transient permafrost model CryoGrid2 (Westermann et al. 2013). Based on the heat transfer equation the model calculates the evolution of the soil temperature for every grid cell. The horizontal grid cell size is determined by the remotely sensed forcing data of MODIS land surface temperature (1x1km) and the snow depth (1x1km) that we compiled from the snow water equivalent (SWE) product of GlobSnow (25x25km) and the snow extent product of MODIS (0.5x0.5km). For the soil domain of the model three stratigraphic classes were identified. The construction of the stratigraphic classification is based on existing stratigraphic data (cores, profiles) and the “educated guess” of researchers familiar with the composition of the ground. (ODER: For the construction of the stratigraphic classification publications on sedimentology, geomorphology and geology of the Lena River Delta, as well as vegetation classification studies, were used.) For each class, a typical soil stratigraphy with volumetric fractions of the soil constituents (that are mineral, organic and water/ice content and porosity), is prescribed. With this defined, the soil thermal properties such as soil thermal conductivity and volumetric soil heat capacity required for the modeling can be inferred. In a first step we focused on the current state of permafrost temperatures. Then we included a spin up and global circulation models to get forcing data for both past and future to get a reliable statistical data set and calculate future permafrost temperatures up to 70 upcoming years. Following the evaluation of the results for the Lena River Delta we extend the study area to the lowland areas of Northeast Siberia, an area of on the order of 10^6 sqkm.