ALBERT

Description: High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually-dated ice core record from the eastern Ross Sea. Comparison of the Roosevelt Island Climate Evolution (RICE) ice core records with climate reanalysis data for the 1979–2012 calibration period shows that RICE records reliably capture temperature and snow precipitation variability of the region. RICE is compared with data from West Antarctica (West Antarctic Ice Sheet Divide Ice Core) and the western (Talos Dome) and eastern (Siple Dome) Ross Sea. For most of the past 2,700 years, the eastern Ross Sea was warming with perhaps increased snow accumulation and decreased sea ice extent. However, West Antarctica cooled whereas the western Ross Sea showed no significant temperature trend. From the 17th Century onwards, this relationship changes. All three regions now show signs of warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea, but increasing in the western Ross Sea. Analysis of decadal to centennial-scale climate variability superimposed on the longer term trend reveal that periods characterised by opposing temperature trends between the Eastern and Western Ross Sea have occurred since the 3rd Century but are masked by longer-term trends. This pattern here is referred to as the Ross Sea Dipole, caused by a sensitive response of the region to dynamic interactions of the Southern Annual Mode and tropical forcings.

Description: High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually dated ice core record from the eastern Ross Sea, named the Roosevelt Island Climate Evolution (RICE) ice core. Comparison of this record with climate reanalysis data for the 1979–2012 interval shows that RICE reliably captures temperature and snow precipitation variability in the region. Trends over the past 2700 years in RICE are shown to be distinct from those in West Antarctica and the western Ross Sea captured by other ice cores. For most of this interval, the eastern Ross Sea was warming (or showing isotopic enrichment for other reasons), with increased snow accumulation and perhaps decreased sea ice concentration. However, West Antarctica cooled and the western Ross Sea showed no significant isotope temperature trend. This pattern here is referred to as the Ross Sea Dipole. Notably, during the Little Ice Age, West Antarctica and the western Ross Sea experienced colder than average temperatures, while the eastern Ross Sea underwent a period of warming or increased isotopic enrichment. From the 17th century onwards, this dipole relationship changed. All three regions show current warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea but increasing in the western Ross Sea. We interpret this pattern as reflecting an increase in sea ice in the eastern Ross Sea with perhaps the establishment of a modern Roosevelt Island polynya as a local moisture source for RICE.

Description: The data set presents results from geospatial analyses of a region in Central Yamal, Western Siberia, which was affected by the construction of the Bovanenkovo railway line and by high Retrogressive Thaw Slumps (RTS) occurrence in consequence of the extremely warm and wet year 2012. A change detection was performed using high resolution optical satellite images from 2010 (GeoEye-1) and 2013 (QuickBird). The preprocessing of the satellite data (orthorectification and atmospheric correction) was performed by and is described in Dvornikov et al., 2016. The degree of disturbance change from 2010 and 2013 around the railway line was classified into three major disturbance levels - low, medium and high, based on the width of disturbance and magnitude of change over the course of three years. A kernel density raster file illustrates RTS distribution. The highest disturbance along the railway can be observed, where the RTS activity is the highest in 2013.

Description: High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually-dated ice core record from the eastern Ross Sea. Comparison of the Roosevelt Island Climate Evolution (RICE) ice core records with climate reanalysis data for the 1979-2012 calibration period shows that RICE records reliably capture temperature and snow precipitation variability of the region. RICE is compared with data from West Antarctica (West Antarctic Ice Sheet Divide Ice Core) and the western (Talos Dome) and eastern (Siple Dome) Ross Sea. For most of the past 2,700 years, the eastern Ross Sea was warming with perhaps increased snow accumulation and decreased sea ice extent. However, West Antarctica cooled whereas the western Ross Sea showed no significant temperature trend. From the 17th Century onwards, this relationship changes. All three regions now show signs of warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea, but increasing in the western Ross Sea. Analysis of decadal to centennial-scale climate variability superimposed on the longer term trend reveal that periods characterised by opposing temperature trends between the Eastern and Western Ross Sea have occurred since the 3rd Century but are masked by longer-term trends. This pattern here is referred to as the Ross Sea Dipole, caused by a sensitive response of the region to dynamic interactions of the Southern Annual Mode and tropical forcings.

Description: 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.

Description: In light of climate warming, ice-rich permafrost landscapes are amongst the most vulnerable areas in the world. In addition, many regions in the Arctic are affected by rapid industrial development as natural resources become more and more accessible through transportation networks and new engineering technologies. The aim of this study is to examine short-term anthropogenic and natural disturbances on permafrost, in particular whether there is a relation between the effects of infrastructure and the occurrence of landslides. The study investigates a region in Central Yamal, Western Siberia, which was affected by the construction of the Bovanenkovo railway line and by high Retrogressive Thaw Slumps (RTS) occurrence in consequence of the extremely warm and wet year 2012. A change detection was performed using high optical satellite images. Furthermore, a kernel density map to illustrate RTS distribution and an analysis of RTS aspects employing a digital elevation model was conducted. To gain a better understanding of climate drivers of landslide occurrence a multifaceted approach of observational climate data, reanalysis on air temperature, precipitation and wind data as well as C-band backscatter data to derive soil moisture and the freeze/thaw soil state was performed. The change detection of anthropogenic disturbance in 2013 showed a decrease of around 40 % compared to 2010: However, active landslides along the railway line can be seen despite of maintenance techniques. The occurrence of 81 RTS at lake margins are mostly located in the flat areas of the study area and are, in contrast to many other studies, less influenced by solar radiation since most of the landslide aspects are facing to the NW and N. The application of reanalysis in remote areas appears to be a beneficial tool, as it reflects the seasonal differences of continental and maritime influenced climate and shows high accuracy with backscatter soil moisture data in the study area. Thus, RTS triggering in 2012 could be attributed to a mild winter, early snow melt, high summer temperatures, and enhanced rainfall rates. Although RTS appears to be a natural phenomenon in the study area, anthropogenic impacts might contribute to the occurrence of RTS, as the biggest hotspot of RTS is observed in close proximity to the railway line.