Circumpolar Active-Layer Permafrost System (CAPS): a global geocryological database on CD and Internet (poster)

p. 407-40

Short time changes of permafrost degradation triggered by anthropogenic impact and climatic events in Yamal Peninsula, Western Siberia 2010 – 2013/2015

The Arctic is affected by rapid climate change, which has substantial impact on permafrost regions and the world as a whole (Raynolds et al., 2014). In the last 30 years Arctic temperatures have risen 0.6 °C per decade, twice as fast as the global average (AMAP, 2011, Schuur et al., 2015). This in turn leads to the degradation of ice-rich permafrost (Grosse et al., 2011) and modifies drainage, increases mass movements and alters landscapes (Nelson et al., 2001; Anisimov et al., 2007, Romanovsky et al., 2010b). Although permafrost regions are not densely populated, their economic importance has increased substantially in recent decades. This is related to the abundance of natural resources in the polar region and improved methods of hydrocarbon extraction, transportation networks to population centers and engineering maintenance systems (Nelson et al., 2002; Mazhitova et al., 2004, AMAP, 2011). The Yamal Peninsula in North West Siberia is experiencing some of the most rapid land cover and land use changes in the Arctic due to a combination of climate change and gas development in one of the most extensive industrial complexes (Kumpula et al., 2006; Walker et al., 2011; Leibman et al., 2015). Specific geological conditions with nutrient-poor sands, massive tabular ground ice and extensive landslides intensify these impacts (Walker et al., 2011). The combination of high natural erosion potential and anthropogenic influence cause extremely intensive rates of erosion (Gubarkov et al., 2014). A considerable amount of recent work has focused on the effects of industrial development to ecological and social implications (Forbes, 1999; Kumpula et al., 2010; Walker et al., 2011). This study aims at exemplarily investigating a region that has been affected by natural and anthropogenic large-scale disturbances within a very short period. The construction of the world’s northernmost railway for the Bovanenkvo Gas Field was finished in 2010. In addition the region experienced an extremly warm and wet summer in 2012. The objectives of this study are • to map surface disturbances of central Yamal between 2010 and 2013/2015 based on highresolution satellite imagery and on the most recent SPOT5-TAKE-5 imagery in 2015, • to quantify natural and anthropogenic impacts in terms of permafrost degradation, • to use meteorological data from the nearest climate station (Marre Sale, Yamal) and from reanalyses climate data on air temperature and precipitation

Modern rates of thermal denudation and thermal abrasion on western Kolguev Island

Destruction mechanisms and dynamics of the Arctic coast, also in the western sector of the Russian Arctic, are studied in detail, including the use of remote sensing data. However, data on thermal abrasion and thermo denudation of Kolguev island is quite limited. Some estimates were presented in article of M.A.Velikotsky (1998). Estimation of thermos denudation rates near the Sauchiha river mouth for the period 1948-2002 years was done by the authors earlier (Kizyakov& Perednya, 2003). To obtain data about the modern (after 2002) shoreline retreat rates and growth of thermal cirque a high resolution remote sensing data were involved in our research. Part of the western coast of the Kolguev island was inspected in field work conducted on 2002 by ECI SB RAS, together with VNIIOkeangeologia. The object of research was the part of coast, including a group of three coastal thermal cirques, located 3.5 km south of the Sauchiha river mouth. In 2012, within the framework of the project ‘Geoportal of MSU’ operational satellite imaging was done on Kolguev island by satellite FORMOSAT-2. High resolution satellite imagery provides ample opportunities for visual interpretation of coastal landforms. Aerial photographs (1948 and 1968), surveying materials (2002), high-resolution satellite images (2009 and 2012) became basis to study the dynamics of the coast and thermal cirques in the key area. For key area were calculated: retreat rates of the edge of the coastal terraces and thermal cirques for the periods 1948-1968, 1968-2002, 2002-2009, 2009-2012; retreat rates of the foot of the coastal terrace for the periods 2002-2009, 2009-2012; volume of the material enters the coastal zone by the thermal abrasion for one linear km of a coast (Kizyakov et al., 2013). Average long-term rates of retreat of the coastal terrace during 1948-2012 varied from 0.7 to 2.4 m/year; 2002-2012 varied from 1.7 to 2.4 m/year. Identified rates are distinctive for the part of coast from the mouth of Krivaya river to the curve of coastline near the mouth of the Gusinaya river - a length is 60.5 km. These rates are in 1.1-1.5 times lower than average rates of retreat of thermal cirque edges which are connected with melting of massive ice deposits. Averaged growth rates of the thermal cirques in 1948-2002 was 2.4 m/year; in 2002-2012 was - 2.6 m/year. The maximum growth rate on some sections in 2009-2012 were 14.5-15.1 m/year. These rates are the largest for the previously recorded in the Western sector of the Russian Arctic. The cause of the abnormally high rates is an increase the annual amount of positive air temperatures, which in 2011-2012 was 1.4-1.5 times higher than the long-term average. The determined rates of the development of thermal cirque can be extended to the north from the key area (near the Sauchiha river mouth) to the Gusinaya river mouth with total length of 32.3 km. The next plans on studying the coastal dynamics on Kolguev Island - using additional satellite images for the purposes of: detailization of interannual dynamics through the analysis of more short time span series of satellite images, definition of variations of the coastal destruction rates on the Western and Northern coasts. References: Velikotsky M.A. Characteristics of modern coastal dynamics of the Kolguev Island // Dynamics of the Russian Arctic coasts, Moscow, MSU – 1989 – P.93- 101 (In Russian) Kizyakov A.I., Perednya D.D. Destruction of coasts on the Yugorsky Peninsula and on Kolguev Island (Russia) // Permafrost: Abstr. of the 8th Intern. Conf. (Zurich, Switzerland, 21–25 July 2003). Zurich, Switzerland – 2003 – P. 79–80. Kizyakov A.I., Zimin M.V., Leibman M.O., Pravikova N.V. Monitoring the rate of thermal denudation and thermal abrasion on the western coast of Kolguev Island using high resolution satellite images // Earth Cryosphere (Kriosfera Zemli). – 2013, XVII, No. 4 – P. 15-25 (In Russian)

Spatial patterns of arctic tundra vegetation properties on different soils along the Eurasia Arctic Transect, and insights for a changing Arctic

Vegetation properties of arctic tundra vary dramatically across its full latitudinal extent, yet few studies have quantified tundra ecosystem properties across latitudinal gradients with field-based observations that can be related to remotely sensed proxies. Here we present data from field sampling of six locations along the Eurasia Arctic Transect in northwestern Siberia. We collected data on the aboveground vegetation biomass, the normalized difference vegetation index (NDVI), and the leaf area index (LAI) for both sandy and loamy soil types, and analyzed their spatial patterns. Aboveground biomass, NDVI, and LAI all increased with increasing summer warmth index (SWI—sum of monthly mean temperatures > 0 °C), although functions differed, as did sandy vs. loamy sites. Shrub biomass increased non-linearly with SWI, although shrub type biomass diverged with soil texture in the southernmost locations, with greater evergreen shrub biomass on sandy sites, and greater deciduous shrub biomass on loamy sites. Moss biomass peaked in the center of the gradient, whereas lichen biomass generally increased with SWI. Total aboveground biomass varied by two orders of magnitude, and shrubs increased from 0 g m−2 at the northernmost sites to >500 g m−2 at the forest-tundra ecotone. Current observations and estimates of increases in total aboveground and shrub biomass with climate warming in the Arctic fall short of what would represent a 'subzonal shift' based on our spatial data. Non-vascular (moss and lichen) biomass is a dominant component (>90% of the photosynthetic biomass) of the vegetation across the full extent of arctic tundra, and should continue to be recognized as crucial for Earth system modeling. This study is one of only a few that present data on tundra vegetation across the temperature extent of the biome, providing (a) key links to satellite-based vegetation indices, (b) baseline field-data for ecosystem change studies, and (c) context for the ongoing changes in arctic tundra vegetation.Non peer reviewe

Northern Hemisphere permafrost map based on TTOP modelling for 2000-2016 at 1 km²scale

Permafrost is a key element of the cryosphere and an essential climate variable in the Global Climate Observing System. There is no remote-sensing method available to reliably monitor the permafrost thermal state. To estimate permafrost distribution at a hemispheric scale, we employ an equilibrium state model for the temperature at the top of the permafrost (TTOP model) for the 2000–2016 period, driven by remotely-sensed land surface temperatures, down-scaled ERA-Interim climate reanalysis data, tundra wetness classes and landcover map from the ESA Landcover Climate Change Initiative (CCI) project. Subgrid variability of ground temperatures due to snow and landcover variability is represented in the model using subpixel statistics. The results are validated against borehole measurements and reviewed regionally. The accuracy of the modelled mean annual ground temperature (MAGT) at the top of the permafrost is ±2 °C when compared to permafrost borehole data. The modelled permafrost area (MAGT 0) is around 21 × 106 km2 (22% of exposed land area), which is approximately 2 × 106 km2 less than estimated previously. Detailed comparisons at a regional scale show that the model performs well in sparsely vegetated tundra regions and mountains, but is less accurate in densely vegetated boreal spruce and larch forests

Lilliput

Catalog for the exhibition Lilliput held at the Seton Hall University Walsh Gallery, June 8 - July 24, 2009. Curated by Jeanne Brasile and Asha Ganpat. Includes an essay by Jeanne Brasile and Asha Ganpat. Includes color illustrations

Northern Hemisphere permafrost map based on TTOP modelling for 2000–2016 at 1 km2 scale

Permafrost is a key element of the cryosphere and an essential climate variable in the Global Climate Observing System. There is no remote-sensing method available to reliably monitor the permafrost thermal state. To estimate permafrost distribution at a hemispheric scale, we employ an equilibrium state model for the temperature at the top of the permafrost (TTOP model) for the 2000–2016 period, driven by remotely- sensed land surface temperatures, down-scaled ERA-Interim climate reanalysis data, tundra wetness classes and landcover map from the ESA Landcover Climate Change Initiative (CCI) project. Subgrid variability of ground temperatures due to snow and landcover variability is represented in the model using subpixel statistics. The results are validated against borehole measurements and reviewed regionally. The accuracy of the modelled mean annual ground temperature (MAGT) at the top of the permafrost is ±2 °C when compared to permafrost borehole data. The modelled permafrost area (MAGT 0) is around 21 × 106 km2 (22% of exposed land area), which is approximately 2 × 106 km2 less than estimated previously. Detailed comparisons at a regional scale show that the model performs well in sparsely vegetated tundra regions and mountains, but is less accurate in densely vegetated boreal spruce and larch forests

Distribution and Morphometry of Thermocirques in the North of West Siberia, Russia

The Arctic zone of West Siberia (Yamal and Gydan peninsulas) is an area with continuous permafrost and tabular ground ice close to the surface, active thermodenudation, and related landforms: retrogressive thaw slumps (RTS); in Russian referred to as thermocirques (TC). The dimensions of most TCs have not been determined so far. We use Sentinel 2 imagery to measure each TC area ranging from 0.55 to 38 ha with a median of 2.5 ha. Around 95% of TCs have an area of less than 10 ha. The largest areas are gained due to the merging of several neighboring TCs. The ArcticDEM is used to determine TC edge elevation and slope angle. In general, the Median TC of the Yamal peninsula has an area of 1.8 ha, an elevation of the edge of 17.7 m, and a slope angle of 2.5°. The Median TC of the Gydan peninsula has an area of 2.6 ha, elevation of the edge of 29.4 m, and slope angle of 3°. TCs of the Gydan peninsula occupy higher positions and slightly steeper slopes compared to TCs of the Yamal peninsula. The ranges of the median and the largest TC areas are consistent with the reported RTS dimensions in North America