Permafrost temperature records: Indicators of climate change

Abstract

Permafrost has received much attention recently because surface temperatures are rising in most permafrost areas of the Earth, bringing permafrost to the edge of widespread thawing and degradation. The thawing of permafrost that already occurs at the southern limits of the permafrost zone can generate dramatic changes in ecosystems and in infrastructure performance. In this article, we describe an emerging system for comprehensive monitoring of permafrost temperatures, a system which is needed for timely detection of worldwide changes in permafrost stability, and for predictions of negative consequences of permafrost degradation. Permafrost is rock, sediment, or any other Earth material with a temperature that remains below 0°C for two or more years. Permafrost zones occupy up to 24% of the exposed land area of the Northern Hemisphere (Figure 1) [Zhang et al., 2000]. Permafrost ranges from very cold (temperatures of −10°C and lower) and very thick (more than 500 m and as much as 1400 m) in the Arctic, to warm (within 1 or 2° of the melting point) and thin (several meters or less in thickness) in the sub‐Arctic.

Pan-Eurasian Experiment (PEEX): towards a holistic understanding of the feedbacks and interactions in the land–atmosphere–ocean–society continuum in the northern Eurasian region

“…An assessment is needed of the impact of climate change in the northern Eurasian region on eutrophication, accompanied by blooms of cyanobacteria. Besides, the northern Eurasian region is characterized by thaw lakes, which comprise 90 % of the lakes in the Russian permafrost zone (Romanovsky et al, 2002). These lakes, which are formed in melting permafrost, have long been known to emit CH 4 .…”

A new map of permafrost distribution on the Tibetan Plateau

“…Due to its unique and extremely high altitude (mean elevation over 4000 m) and low mean annual air temperatures (generally lower than −2 • C with an intra-annual amplitude over 20 • C in the permafrost region), the Tibetan Plateau (TP) possesses the largest areas of permafrost in the mid-and lowlatitude regions of the world Zhao et al, 2004Zhao et al, , 2010Yang et al, 2010). Permafrost and its dynamics complicate the water and energy exchange between soil and atmosphere and thereby introduce greater uncertainty into global climate models (GCMs) that predict climate change (Romanovsky et al, 2002;Smith and Riseborough, 2002;Cheng and Wu, 2007;Riseborough et al, 2008;Zhao et al, 2010). To generate better quantitative simulations, a more accurate TP permafrost distribution is needed.…”

Evapotranspiration in Northern Agro-Ecosystems: Numerical Simulation and Experimental Comparison

“…An active layer on top of the permafrost experiences seasonal thaws and is the primary dominant subsurface component of the land-atmosphere system [5]. Under climate warming scenario, much of this terrain would be vulnerable to subsidence, particularly in ice-rich areas of relatively warm, discontinuous permafrost, and shrinking ponds and lakes [3,[6][7][8][9][10]. All these changes will potentially alter the exchange of surface energy, water, and carbon cycles in high-latitude ecosystems [11] and consequently, the response at regional level to the atmosphere system.…”