Papers on permafrost thawing

This is a list of papers on permafrost thawing. The list is not complete, and will most likely be updated in the future in order to make it more thorough and more representative.

UPDATE (April 5, 2012): Fedotov et al. (2012) added.

Permafrost thawing inferred from Arctic lake sediment of the Taimyr Peninsula, East Siberia, Russia – Fedotov et al. (2012) “The objective of this paper is to reconstruct permafrost thawing at 71°N of Arctic Siberia during the termination of the Little Ice Age and the subsequent Recent Warming. Sediment samples from Lake Dalgan of the Taimyr Peninsula were analysed by high-resolution X-ray fluorescence spectroscopy at 1 mm scan resolution, and Fourier-transform infrared techniques. Intense permafrost thawing was calculated from the level of terrigenous and leached matter supplied by meltwater into the lakes. We defined three episodes of increased permafrost thawing during the last 170 years. The first maximum of permafrost melting occurred from 1870 to 1880, the second episode was from 1900 to 1930 and the third began from 1960 and continues to date. During these periods, maxima of permafrost melting occurred with a specific time lag following temperature maxima.” A.P. Fedotova, M.A. Phedorin, A.S. Suvorov, M.S. Melgunov & T.V. Khodzher, International Journal of Environmental Studies, Volume 69, Issue 1, 2012, DOI:10.1080/00207233.2012.619879.

Estimation of permafrost thawing rates in a sub-arctic catchment using recession flow analysis – Lyon et al. (2009) “Permafrost thawing is likely to change the flow pathways taken by water as it moves through arctic and sub-arctic landscapes. The location and distribution of these pathways directly influence the carbon and other biogeochemical cycling in northern latitude catchments. While permafrost thawing due to climate change has been observed in the arctic and sub-arctic, direct observations of permafrost depth are difficult to perform at scales larger than a local scale. Using recession flow analysis, it may be possible to detect and estimate the rate of permafrost thawing based on a long-term streamflow record. We demonstrate the application of this approach to the sub-arctic Abiskojokken catchment in northern Sweden. Based on recession flow analysis, we estimate that permafrost in this catchment may be thawing at an average rate of about 0.9 cm/yr during the past 90 years. This estimated thawing rate is consistent with direct observations of permafrost thawing rates, ranging from 0.7 to 1.3 cm/yr over the past 30 years in the region.” S. W. Lyon, G. Destouni, R. Giesler, C. Humborg, M. Mörth, J. Seibert, J. Karlsson, and P. A. Troch, Hydrol. Earth Syst. Sci., 13, 595-604, 2009, doi:10.5194/hess-13-595-2009. [Full text]

Responses of permafrost to climate change and their environmental significance, Qinghai-Tibet Plateau – Cheng & Wu (2007) “In this paper we summarize recent research in geocryological studies carried out on the Qinghai-Tibet Plateau that show responses of permafrost to climate change and their environmental implications. Long-term temperature measurements indicate that the lower altitudinal limit of permafrost has moved up by 25 m in the north during the last 30 years and between 50 and 80 m in the south over the last 20 years. Furthermore, the thickness of the active layer has increased by 0.15 to 0.50 m and ground temperature at a depth of 6 m has risen by about 0.1° to 0.3°C between 1996 and 2001. Recent studies show that freeze-thaw cycles in the ground intensify the heat exchange between the atmosphere and the ground surface. The greater the moisture content in the soil, the greater is the influence of freeze-thaw cycling on heat exchange. The water and heat exchange between the atmosphere and the ground surface due to soil freezing and thawing has a significant influence on the climate in eastern Asia. A negative correlation exists between soil moisture and heat balance on the plateau and the amount of summer precipitation in most regions of China. A simple frozen soil parameterization scheme was developed to simulate the interaction between permafrost and climate change. This model, combined with the NCAR Community Climate Model 3.6, is suitable for the simulation of permafrost changes on the plateau. In addition, permafrost degradation is one of the main causes responsible for a dropping groundwater table at the source areas of the Yangtze River and Yellow River, which in turn results in lowering lake water levels, drying swamps and shrinking grasslands.” Cheng, G., and T. Wu (2007), J. Geophys. Res., 112, F02S03, doi:10.1029/2006JF000631. [Full text]

A projection of severe near-surface permafrost degradation during the 21st century – Lawrence & Slater (2005) “The current distribution and future projections of permafrost are examined in a fully coupled global climate model, the Community Climate System Model, version 3 (CCSM3) with explicit treatment of frozen soil processes. The spatial extent of simulated present-day permafrost in CCSM3 agrees well with observational estimates – an area, excluding ice sheets, of 10.5 million km2. By 2100, as little as 1.0 million km2 of near-surface permafrost remains. Freshwater discharge to the Arctic Ocean rises by 28% over the same period, largely due to increases in precipitation that outpace increases in evaporation, with about 15% of the rise directly attributable to melting ground ice. Such large changes in permafrost may provoke feedbacks such as activation of the soil carbon pool and a northward expansion of shrubs and forests.” Lawrence, D. M., and A. G. Slater (2005), Geophys. Res. Lett., 32, L24401, doi:10.1029/2005GL025080. [Full text]

Permafrost Thaw Accelerates in Boreal Peatlands During Late-20th Century Climate Warming – Camill (2005) “Permafrost covers 25% of the land surface in the northern hemisphere, where mean annual ground temperature is less than 0°C. A 1.4–5.8 °C warming by 2100 will likely change the sign of mean annual air and ground temperatures over much of the zones of sporadic and discontinuous permafrost in the northern hemisphere, causing widespread permafrost thaw. In this study, I examined rates of discontinuous permafrost thaw in the boreal peatlands of northern Manitoba, Canada, using a combination of tree-ring analyses to document thaw rates from 1941–1991 and direct measurements of permanent benchmarks established in 1995 and resurveyed in 2002. I used instrumented records of mean annual and seasonal air temperatures, mean winter snow depth, and duration of continuous snow pack from climate stations across northern Manitoba to analyze temporal and spatial trends in these variables and their potential impacts on thaw. Permafrost thaw in central Canadian peatlands has accelerated significantly since 1950, concurrent with a significant, late-20th-century average climate warming of +1.32 °C in this region. There were strong seasonal differences in warming in northern Manitoba, with highest rates of warming during winter (+1.39 °C to +1.66 °C) and spring (+0.56 °C to +0.78 °C) at southern climate stations where permafrost thaw was most rapid. Projecting current warming trends to year 2100, I show that trends for north-central Canada are in good agreement with general circulation models, which suggest a 4–8 °C warming at high latitudes. This magnitude of warming will begin to eliminate most of the present range of sporadic and discontinuous permafrost in central Canada by 2100.” Philip Camill, Climatic Change, Volume 68, Numbers 1-2, 135-152, DOI: 10.1007/s10584-005-4785-y.

Spatial and temporal variability in active layer thickness over the Russian Arctic drainage basin – Zhang et al. (2005) “Changes in active layer thickness (ALT) over northern high-latitude permafrost regions have important impacts on the surface energy balance, hydrologic cycle, carbon exchange between the atmosphere and the land surface, plant growth, and ecosystems as a whole. This study examines the 20th century variations of ALT for the Ob, Yenisey, and Lena River basins. ALT is estimated from historical soil temperature measurements from 17 stations (1956–1990, Lena basin only), an annual thawing index based on both surface air temperature data (1901–2002) and numerical modeling (1980–2002). The latter two provide spatial fields. Based on the thawing index, the long-term average (1961–1990) ALT is about 1.87 m in the Ob, 1.67 in the Yenisey, and 1.69 m in the Lena basin. Over the past several decades, ALT over the three basins shows positive trends, but with different magnitudes. Based on the 17 stations, ALT increased about 0.32 m between 1956 and 1990 in the Lena. To the extent that results based on the soil temperatures represent ground “truth,” ALT obtained from both the thawing index and numerical modeling is underestimated. It is widely believed that ALT will increase with global warming. However, this hypothesis needs further refinement since ALT responds primarily to summer air temperature while observed warming has occurred mainly in winter and spring. It is also shown that ALT exhibits complex and inconsistent responses to variations in snow cover.” Zhang, T., et al. (2005), J. Geophys. Res., 110, D16101, doi:10.1029/2004JD005642.

Accelerated thawing of subarctic peatland permafrost over the last 50 years – Payette et al. (2004) “In this study we provide a quantification of the main patterns of change of a subarctic peatland caused by permafrost decay monitored between 1957 and 2003. Up-thrusting of the peatland surface due to permafrost aggradation during the Little Ice Age resulted in the formation of an extensive peat plateau that gradually fragmented into residual palsas from the 19th century to the present. Only about 18% of the original surface occupied by permafrost was thawed in 1957, whereas only 13% was still surviving in 2003. Rapid permafrost melting over the last 50 years caused the concurrent formation of thermokarst ponds and fen-bog vegetation with rapid peat accumulation through natural successional processes of terrestrialization. The main climatic driver for accelerated permafrost thawing was snow precipitation which increased from 1957 to present while annual and seasonal temperatures remained relatively stable until about the mid-1990s when annual temperature rose well above the mean. Contrary to current expectations, the melting of permafrost caused by recent climate change does not transform the peatland to a carbon-source ecosystem as rapid terrestrialization exacerbates carbon-sink conditions and tends to balance the local carbon budget.” Payette, S., A. Delwaide, M. Caccianiga, and M. Beauchemin (2004), Geophys. Res. Lett., 31, L18208, doi:10.1029/2004GL020358. [Full text]

Permafrost thaw and destabilization of Alpine rock walls in the hot summer of 2003 – Gruber et al. (2004) “Exceptional rockfall occurred throughout the Alps during the unusually hot summer of 2003. It is likely related to the fast thermal reaction of the subsurface of steep rock slopes and a corresponding destabilization of ice-filled discontinuities. This suggests that rockfall may be a direct and unexpectedly fast impact of climate change. Based upon our measurements in Alpine rock faces, we present model simulations illustrating the distribution and degradation of permafrost where the summer of 2003 has resulted in extreme thaw. We argue that hotter summers predicted by climate models for the coming decades will result in reduced stability of many alpine rock walls.” Gruber, S., M. Hoelzle, and W. Haeberli (2004), Geophys. Res. Lett., 31, L13504, doi:10.1029/2004GL020051. [Full text]

Thawing sub-arctic permafrost: Effects on vegetation and methane emissions – Christensen et al. (2004) “Ecosystems along the 0°C mean annual isotherm are arguably among the most sensitive to changing climate and mires in these regions emit significant amounts of the important greenhouse gas methane (CH₄) to the atmosphere. These CH₄ emissions are intimately related to temperature and hydrology, and alterations in permafrost coverage, which affect both of those, could have dramatic impacts on the emissions. Using a variety of data and information sources from the same region in subarctic Sweden we show that mire ecosystems are subject to dramatic recent changes in the distribution of permafrost and vegetation. These changes are most likely caused by a warming, which has been observed during recent decades. A detailed study of one mire show that the permafrost and vegetation changes have been associated with increases in landscape scale CH₄ emissions in the range of 22–66% over the period 1970 to 2000.” Christensen, T. R., T. Johansson, H. J. Åkerman, M. Mastepanov, N. Malmer, T. Friborg, P. Crill, and B. H. Svensson (2004), Geophys. Res. Lett., 31, L04501, doi:10.1029/2003GL018680.

Thermokarst ponds as indicators of the former distribution of palsas in Finnish Lapland – Luoto & Seppälä (2003) “Thermokarst ponds resulting from thawing of palsas were mapped in a 95 km-long transect area in northern Finland. The spatial distribution of thermokarst was related to palsa distribution and to geographical variables using GIS techniques and multivariate spatial modelling. In our 3370 km2 study area, the former distribution of palsas was about three times larger than the present one. This indicates that the formation and thawing of permafrost are not in balance; palsas are collapsing and melting more often than palsas are forming.” Miska Luoto, Matti Seppälä, Permafrost and Periglacial Processes, Volume 14, Issue 1, pages 19–27, January/March 2003, DOI: 10.1002/ppp.441.

Recent decay of a single palsa in relation to weather conditions between 1996 and 2000 in Laivadalen, northern Sweden – Zuidhoff (2002) “This study presents the decay of a small palsa complex between 1996 and 2000 in Sweden’s southernmost major palsa bog. The outline of the palsa was mapped during three summers in 1996, 1999 and 2000 and an automatic weather station measured air temperature, precipitation, snow depth, wind speed and wind direction between 1997 and 2000. The decay of the palsa was enormous in the dome–shaped part of the palsa complex: the height decreased during the observation period from 2.3 m to 0.5 m. In 2000, the palsa dome had almost totally disappeared: only some peat blocks in a palsa pond were left. The decay of the palsa was complex with a number of degradational processes, of which the main processes were block erosion, thermokarst and wind erosion. Thermal melting has occurred along the edges of the palsa and possibly below the frozen core of the palsa since 1998/99. Wind erosion was observed during summer and the maximum estimated deflation was 80 cm. The decay of the palsa dome was especially large between 1999 and 2000, probably due to a high mean annual temperature, high summer precipitation and the warming influence of the large pond surrounding the palsa. The present climate in the palsa bog with a mean annual temperature of −0.8°C is not favourable for palsa development and maintenance, despite a strong wind regime which can provide suitable conditions for snowdrift.” Frieda Sjoukje Zuidhoff, Geografiska Annaler: Series A, Physical Geography, Volume 84, Issue 2, pages 103–111, August 2002, DOI: 10.1111/1468-0459.00164.

Permafrost Degradation and Ecological Changes Associated with a WarmingClimate in Central Alaska – Jorgenson et al. (2001) “Studies from 1994–1998 on the TananaFlats in central Alaska reveal that permafrostdegradation is widespread and rapid, causing largeshifts in ecosystems from birch forests to fens andbogs. Fine-grained soils under the birch forest areice-rich and thaw settlement typically is 1–2.5 mafter the permafrost thaws. The collapsed areas arerapidly colonized by aquatic herbaceous plants,leading to the development of a thick, floatingorganic mat. Based on field sampling of soils,permafrost and vegetation, and the construction of aGIS database, we estimate that 17% of the study area(263,964 ha) is unfrozen with no previous permafrost,48% has stable permafrost, 31% is partiallydegraded, and 4% has totally degraded. For thatportion that currently has, or recently had,permafrost (83% of area), 42% has been affected bythermokarst development. Based on airphoto analysis,birch forests have decreased 35% and fens haveincreased 29% from 1949 to 1995. Overall, the areawith totally degraded permafrost (collapse-scar fensand bogs) has increased from 39 to 47% in 46 y. Based on rates of change from airphoto analysis andradiocarbon dating, we estimate 83% of thedegradation occurred before 1949. Evidence indicatesthis permafrost degradation began in the mid-1700s andis associated with periods of relatively warm climateduring the mid-late 1700s and 1900s. If currentconditions persist, the remaining lowland birchforests will be eliminated by the end of the nextcentury.” M.Torre Jorgenson, Charles H. Racine, James C. Walters and Thomas E. Osterkamp, Climatic Change, Volume 48, Number 4, 551-579, DOI: 10.1023/A:1005667424292. [Full text]

Long-Term Monitoring of Permafrost Change in a Palsa Peatland in Northern Quebec, Canada: 1983-1993 – Laberge & Payette (1995) “Changes in the spatial distribution of permafrost in the Ouiatchouane palsa peatland (northern Quebec) were monitored from 1957 to present, using aerial photographs taken in 1957 (starting date) and three field surveys in 1973, 1983, and 1993, respectively. Between 1983 and 1993, palsa degradation occurred at about the same rate as between 1957 and 1983, although minor differences in rate of permafrost decay during the three periods (1957-1973, 1973-1983, 1983-1993) may be attributed in part to misidentification of marginal permafrost landforms. Permafrost degradation appeared to be influenced by height of individual palsas and their location within the peatland. Since 1983, thermokarst ponds have been progressively invaded by sedges and Sphagnum, a situation promoting successional peatland development and palsa formation as suggested by the presence of a small incipient palsa. Although the main geomorphic process at work is palsa degradation, permafrost aggradation is possible under present climatic conditions.” Marie-Josée Laberge and Serge Payette, Arctic and Alpine Research, Vol. 27, No. 2 (May, 1995), pp. 167-171. [Full text]

Effects of Changes in Groundwater Level on Palsas in Central Iceland – Thórhallsdóttir (1994) “In the central highland of Iceland, the creation of a small lake partly flooded a dried-up palsa bog. The palsas upshore experienced raised summer soilwater levels and inundation during winter. The effects of these changed hydrological conditions on 5 palsas were monitored over a period of 5 years. All the palsas increased in height, from 14 to 43 cm, with a mean of 27 cm. A core through one palsa showed that while it was formed by segregation ice, the observed height increases were caused by the addition of a layer of pure ice.” Thóra Ellen Thórhallsdóttir, Geografiska Annaler. Series A, Physical Geography, Vol. 76, No. 3 (1994), pp. 161-167.

Distribution and thawing of permafrost in the southern part of the discontinuous permafrost zone in Manitoba – Thie (1974) “This study was carried out to evaluate the environmental factors which influence the distribution and collapse of perennially frozen peats in the southern part of the discontinuous permafrost zone in Manitoba. The changes in permafrost bodies were measurebdy means of aerial photography carried out over a period of 20 years. About 25 per cent of the once occurring permafrost is still present. Melting appears to have exceeded aggradation of permafrost since about 150 years B.P. Two types of collapse were noticed: peripheral collapse around very small permafrost bodies; and a central collapse for the larger bodies. The amount of collapse has varied from 0 to 30 metres horizontally in a 20 year period.” Thie, J., Arctic, 27, 189– 200. [Full text]