Active-layer thermal monitoring on the Fildes Peninsula, King George Island, maritime Antarctica

Abstract

Abstract. International attention to climate change phenomena has grown in the last decade; the active layer and permafrost are of great importance in understanding processes and future trends due to their role in energy flux regulation. The objective of this paper is to present active-layer temperature data for one Circumpolar Active Layer Monitoring South hemisphere (CALM-S) site located on the Fildes Peninsula, King George Island, maritime Antarctica over an 57-month period (2008-2012). The monitoring site was installed during the summer of 2008 and consists of thermistors (accuracy of ±0.2 • C), arranged vertically with probes at different depths, recording data at hourly intervals in a highcapacity data logger. A series of statistical analyses was performed to describe the soil temperature time series, including a linear fit in order to identify global trends, and a series of autoregressive integrated moving average (ARIMA) models was tested in order to define the best fit for the data. The affects of weather on the thermal regime of the active layer have been identified, providing insights into the influence of climate change on permafrost. The active-layer thermal regime in the studied period was typical of periglacial environments, with extreme variation in surface during the summer resulting in frequent freeze and thaw cycles. The active-layer thickness (ALT) over the studied period shows a degree of variability related to different annual weather conditions, reaching a maximum of 117.5 cm in 2009. The ARIMA model could describe the data adequately and is an important tool for more conclusive analysis and predictions when longer data sets are available. Despite the variability when comparing temperature readings and ACT over the studied period, no trend can be identified.

Pedoclimate monitoring in the periglacial high mountain soils of the Atacama Desert, northern Chile

“…At all sites average monthly soil temperature at 5 cm depth was higher than the average monthly air temperature, indicating the importance of solar radiation in supplying energy to the soil. A similar behavior of the soil surface and air temperature has been observed within periglacial environments . These authors attribute the higher soil surface temperature than air temperature to snow‐free periods.…”

Holocene deglaciation and glacier readvances on the Fildes Peninsula and King George Island (Isla 25 de Mayo), South Shetland Islands, NW Antarctic Peninsula

“…The annual mean air temperature on KGI between 1948 and 2011 CE was -2.5 ºC (Kejna et al, 2013). Mean annual, summer and winter air temperatures at the Russian Bellingshausen Station, Fildes Peninsula, between 1968CE (Olivia et al, 2017) and (1968-2021 (BAS READER project -Reference Antarctic Data for Environmental Research; Turner et al, 2004) were -2.3°C (-2.3±3.1°C), 1.1°C (1.1±0.8°C) and -6.1°C (-5.9±1.7°C), respectively, with mean summer air temperatures above zero and snow free conditions (at sea level) up to four months between December and March (Michel et al, 2014). Mean annual, summer and winter wind velocities recorded at Bellingshausen (1968-2021 were 26.5±3.5 km h -1 , 23.8±2.2 km h -1 , 27.3±3.2 km h -1, respectively.…”

Apparent thermal diffusivity of soil in ice-free areas of Keller peninsula in maritime Antarctica

“…where ATD = apparent thermal diffusivity (m 2 /s), ∆t = time increments (s), ∆Z = space increments (m), T = temperature, j = temporal position and i = depth position. Several authors have used this equation to assess the resistance to energy flux in the soil profile (Nelson et al 1985, Outcalt & Hinkel 1989, Hinkel et al 2001, Michel et al 2014, Almeida et al 2014. For all sites, ATD was estimated by using hourly records for intermediate depths of both profiles, and mean values were calculated and plotted for each hour.…”

“…However, modeling studies incorporating soil moisture parameters are still scarce and little explored. It's extremely important since soil moisture varies greatly in time and space in ice-free areas, leading to alterations on soil thermal regime (Michel et al 2014), especially in maritime Antarctica where a greater rain and solar incidence have enhanced soil formation and vegetation growth more than other parts of Antarctica. It is also known that a number of solutes (molecules or ions) dispersed in the soil solution can decrease the freezing point of a non-volatile liquid (cryoscopy).…”