The occurrence of atmospheric thaw in Poland over the last 50 years
Air temperature ; Atmospheric circulation ; Climatic data ; Climatic variability ; Climatology ; Interannual variability ; Poland ; Seasonal variability ; Spatial distribution ; Thawing
The study is concerned with the temporal and spatial characterisation of atmospheric thaw variability in Poland. The phenomenon was described on the basis of mean daily values of air temperature for the winter months October-March over the period
1960/61-2009/10 obtained from 34 meteorological stations. It has been shown that atmospheric thaws occur on average as soon as 10 days after the first instance of a decrease in temperature below 0°C lasting at least 3 days. Atmospheric thaws
are a constant element of the climate in Poland and occur with a frequency of 30-45% of the calendar winter (December-February) and 30% to almost 50% of the period of the thermic winter. Thaws are most common in the western part of Poland, particularly
in the north-west. The spatial distribution of thaw is strongly dependent on longitude and less on height above sea level. Multiyear variability of thaw days is determined by atmospheric circulation. The role of circulation expressed by NAO index
in the explanation of the variability of thaw occurrence was statistically insignificant.
The AA. review the literature that has contributed to our understanding of patterns, processes and feedbacks, and the environmental consequences of thermokarst, focusing on hillslope, thaw lake and wetland processes. Advances in remote sensing
with warming permafrost, changes in talik geometry and accelerated thaw slump activity, and thaw lake expansion. Thermokarst research provides an important context for studying the environmental implications of permafrost degradation. Investigation
of the interactions between thermokarst and hydrologic and ecological processes has improved knowledge of the feedbacks that accelerate change or lead to stabilisation in terrestrial and thaw lake environments. Finally, the influence of permafrost thaw on soil carbon
The paper includes first a brief summary of relevant aspects of the martian climate, and a short description of the most common landforms thought to be indicative of near-surface ice (with or without thaw) on Mars. Three such landform assemblages
, patterned ground, debris-covered glaciers and hillslope stripes; and an equatorial assemblage of linked basins, patterned ground, possible pingos, and channel-and-scarp features interpreted to be retrogressive thaw-slumps. Hypotheses to explain
these observations are explored, including recent climate change, and hydrated minerals in the regolith thawing to form liquid brines at very low temperatures. The use of terrestrial analogue field sites is also discussed.
Arctic Region ; Asian part of Russia ; Climatic change ; Cold area ; Eastern Siberia ; Geochemistry ; Holocene ; Hydroclimatology ; Ice wedge ; Isotope analysis ; Lake ; Palaeolimnology ; Periglacial features ; Permafrost ; Polar region ; Thawing
cal. kyr BP from Lake El'gene-Kyuele of northeastern Siberia. Eight fine sand layers are attributed to depositional events associated with thaw slump activity acting upon orthogonally oriented patterns of ice-wedge networks in the ice-rich permafrost
of oxidisation. The results indicate a relationship between repeated phases of fine sand input and retrogressive thaw slumping dependent on hydroclimate variability and orthogonally oriented.
Here, the AA. develop a mechanical model that relates the destabilization of thawing permafrost rock slopes to temperature-related effects on both, rock- and ice-mechanics; and laboratory testing of key assumptions is performed. The destabilization
-saturated rock thaws. Based on literature and experiments, the AA. develop a modified Mohr-Coulomb failure criterion for ice-filled rock fractures that incorporates fracturing of rock bridges, friction of rough fracture surfaces, ductile creep of ice
Carbon ; Climatic change ; Geochemistry ; Geosystem ; Model ; Periglacial features ; Permafrost ; Soil properties ; Spatial distribution ; Thawing ; Thermokarst
of the permafrost C pool should be developed to address potential C release upon thaw. The permafrost C pool and its dynamics are beginning to be incorporated into Earth System models.
prospective increase of Fall and Winter stream flows as due to increased liquid precipitation. Lower discharges are projected during Spring and Summer, in view of decreased rainfall and snow cover at thaw, and the CCSM3 model provides shifting of thaw season
Alps (The) ; C 14 dating ; Carbon ; Carbon sequestration ; Comparative study ; Geochemistry ; Mountain ; Permafrost ; Soil ; Soil properties ; Switzerland ; Thawing ; Tree line ; Vegetation
The AA. investigated the potential effect of permafrost thawing by the analysis of the physical-chemical soil properties of permafrost versus non-permafrost sites. Specifically, they 1) quantified the SOM stocks at such sites, 2) characterised SOM
. Strategies include : using observations of fractional snow cover in spring and fall to restrict estimates of photosynthetic uptake; combining observations of snow accumulation and soil freeze/thaw with observations of air temperature to generate more
in great detail. The active layer of the top plateau edge is characterized by high moisture content due to rain before freeze-up in autumn and cornice meltdown during spring thaw. Thus frost weathering there can be very efficient. The cornice will either