scholarly journals Extreme Temperatures in the Antarctic

2021 ◽  
pp. 1-49
Author(s):  
John Turner ◽  
Hua Lu ◽  
John King ◽  
Gareth J. Marshall ◽  
Tony Phillips ◽  
...  
Keyword(s):  
High Temperatures ◽  
Antarctic Peninsula ◽  
Potential Temperature ◽  
Extreme Temperatures ◽  
Near Surface ◽  
Frequency Distributions ◽  
Air Temperatures ◽  
Late Twentieth ◽  
Antarctic Continent ◽  
The Antarctic

AbstractWe present the first Antarctic-wide analysis of extreme near-surface air temperatures based on data collected up to the end of 2019 as part of the synoptic meteorological observing programs. We consider temperatures at 17 stations on the Antarctic continent and nearby sub-Antarctic islands. We examine the frequency distributions of temperatures and the highest and lowest individual temperatures observed. The variability and trends in the number of extreme temperatures were examined via the mean daily temperatures computed from the 0, 6, 12 and 18 UTC observations, with the thresholds for extreme warm and cold days taken as the 5th and 95th percentiles. The five stations examined from the Antarctic Peninsula region all experienced a statistically significant increase (p < 0.01) in the number of extreme high temperatures in the late Twentieth Century part of their records, although the number of extremes decreased in subsequent years. For the period after 1979 we investigate the synoptic background to the extreme events using ECMWF ERA-Interim reanalysis fields. The majority of record high temperatures were recorded after the passage of airmasses over high orography, with the air being warmed by the Föhn effect. At some stations in coastal East Antarctica the highest temperatures were recorded after air with a high potential temperature descended from the Antarctic plateau, resulting in an airmass 5-7°C warmer than the maritime air. Record low temperatures at the Antarctic Peninsula stations were observed during winters with positive sea ice anomalies over the Bellingshausen and Weddell Seas.

Aspects of modern Antarctic meteorology and climatology

2005 ◽  
Vol 32 (2) ◽  
pp. 334-345
Author(s):  
John Turner
Keyword(s):  
Southern Ocean ◽  
Southern Oscillation ◽  
Coastal Region ◽  
First Century ◽  
Near Surface ◽  
Weather Forecasts ◽  
Air Temperatures ◽  
Oceanic Climate ◽  
Antarctic Continent ◽  
The Antarctic

Great advances have been made in recent years in our understanding of the weather of the Antarctic and how the climate of the continent varies on a range of time-scales. The observations from the stations are still the most accurate meteorological measurements that we have, but satellites have been important in providing data for remote parts of the continent and the Southern Ocean. With the large amount of data that is available today weather forecasts are much more accurate than just a few years ago and can provide valuable guidance up to several days ahead over the Southern Ocean and Antarctic coastal region. However, predicting the weather for the interior of the Antarctic is still very difficult. Recent research has shown that the climate of the Antarctic is affected by tropical atmospheric and oceanic climate cycles, such as the El Niño-Southern Oscillation, but the links are complex. The picture of climate change across the Antarctic during the last 50 years is complex, with only the Antarctic Peninsula showing a significant warming. By the end of the twenty-first century near-surface air temperatures across much of the Antarctic continent are expected to increase by several degrees. A small increase in precipitation is also expected.

scholarly journals An Assessment of ERA5 Reanalysis for Antarctic Near-Surface Air Temperature

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 217
Author(s):  
Jiangping Zhu ◽  
Aihong Xie ◽  
Xiang Qin ◽  
Yetang Wang ◽  
Bing Xu ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Antarctic Peninsula ◽  
Austral Summer ◽  
Correlation Coefficients ◽  
East Antarctica ◽  
West Antarctica ◽  
Austral Spring ◽  
Reanalysis Dataset ◽  
Near Surface ◽  
The Antarctic

The European Center for Medium-Range Weather Forecasts (ECMWF) released its latest reanalysis dataset named ERA5 in 2017. To assess the performance of ERA5 in Antarctica, we compare the near-surface temperature data from ERA5 and ERA-Interim with the measured data from 41 weather stations. ERA5 has a strong linear relationship with monthly observations, and the statistical significant correlation coefficients (p < 0.05) are higher than 0.95 at all stations selected. The performance of ERA5 shows regional differences, and the correlations are high in West Antarctica and low in East Antarctica. Compared with ERA5, ERA-Interim has a slightly higher linear relationship with observations in the Antarctic Peninsula. ERA5 agrees well with the temperature observations in austral spring, with significant correlation coefficients higher than 0.90 and bias lower than 0.70 °C. The temperature trend from ERA5 is consistent with that from observations, in which a cooling trend dominates East Antarctica and West Antarctica, while a warming trend exists in the Antarctic Peninsula except during austral summer. Generally, ERA5 can effectively represent the temperature changes in Antarctica and its three subregions. Although ERA5 has bias, ERA5 can play an important role as a powerful tool to explore the climate change in Antarctica with sparse in situ observations.

Soil tardigrades from the Antarctic Peninsula with a description of a new species and some remarks on the genusRamajendas(Eutardigrada: Isohypsibiidae)

Polar Record ◽  
2013 ◽  
Vol 50 (2) ◽  
pp. 176-182 ◽  
Author(s):  
Łukasz Kaczmarek ◽  
Karel Janko ◽  
Jerzy Smykla ◽  
Łukasz Michalczyk
Keyword(s):  
New Species ◽  
Antarctic Peninsula ◽  
Morphometric Characters ◽  
Antarctic Continent ◽  
Fourth Species ◽  
The Antarctic ◽  
A New Species ◽  
Mixed Samples ◽  
Hypsibius Dujardini

ABSTRACTIn thirteen (mostly soil) mixed samples, collected from nine localities on the Antarctic continent and some of the neighbouring islands, 788 specimens and 32 eggs of tardigrades were found. In total, five species were identified:Acutuncus antarcticus, Echiniscus jenningsi,Diphascon(D.)victoriae,Hypsibius dujardiniandRamajendas dastychisp. nov.A. antarcticuswas the most abundant (nearly 90% of all specimens) and was the prevailing taxon found in the majority of locations.R. dastychisp. nov. is the fourth species described in the exclusively Antarctic/sub-Antarctic genus. The new species differs from all other congeners by the presence of four gibbosities on the caudo-dorsal cuticle (configuration II:2–2) and also by some morphometric characters. In this paper we also briefly discuss the taxonomy and zoogeography of the genusRamajendas.

scholarly journals Active layer thermal regime in two climatically contrasted sites of the Antarctic Peninsula region

2016 ◽  
Vol 42 (2) ◽  
pp. 457 ◽  
Author(s):  
F. Hrbáček ◽  
M. Oliva ◽  
K. Laska ◽  
J. Ruiz-Fernández ◽  
M. A. De Pablo ◽  
...  
Keyword(s):  
Active Layer ◽  
Antarctic Peninsula ◽  
Thermal Regime ◽  
Active Layer Thickness ◽  
Mean Annual Temperature ◽  
Climate Trends ◽  
Ground Temperatures ◽  
Air Temperatures ◽  
Discontinuous Permafrost ◽  
The Antarctic

Permafrost controls geomorphic processes in ice-free areas of the Antarctic Peninsula (AP) region. Future climate trends will promote significant changes of the active layer regime and permafrost distribution, and therefore a better characterization of present-day state is needed. With this purpose, this research focuses on Ulu Peninsula (James Ross Island) and Byers Peninsula (Livingston Island), located in the area of continuous and discontinuous permafrost in the eastern and western sides of the AP, respectively. Air and ground temperatures in as low as 80 cm below surface of the ground were monitored between January and December 2014. There is a high correlation between air temperatures on both sites (r=0.74). The mean annual temperature in Ulu Peninsula was -7.9 ºC, while in Byers Peninsula was -2.6 ºC. The lower air temperatures in Ulu Peninsula are also reflected in ground temperatures, which were between 4.9 (5 cm) and 5.9 ºC (75/80 cm) lower. The maximum active layer thickness observed during the study period was 52 cm in Ulu Peninsula and 85 cm in Byers Peninsula. Besides climate, soil characteristics, topography and snow cover are the main factors controlling the ground thermal regime in both areas.

Bellingshausen and the discovery of Antarctica

Polar Record ◽  
1971 ◽  
Vol 15 (99) ◽  
pp. 887-889 ◽  
Author(s):  
Terence Armstrong
Keyword(s):  
Antarctic Peninsula ◽  
West Coast ◽  
North West ◽  
The North ◽  
Antarctic Continent ◽  
The Antarctic

For the last twenty years there has been considerable Soviet interest in the circumnavigation of Antarctica by the Russian naval expedition of 1819–21, led by Captain T. T. Bellingshausen, with Lieut M. P. Lazarev as his second in command, in the sloops Vostok and Mirnyy. It is now reasonably certain that Bellingshausen sighted the Antarctic continent several times, notably on 27 January 1820 (New Style) at a point about lat 69°21′S, long 2°14′W, and was thus the first to see it (Edward Bransfield sighted the north-west coast of the Antarctic Peninsula at about lat 63°50′S, long 60°30′W on 30 January 1820, three days later). Bellingshausen did not claim to have done so however, but his descriptions of what he saw tally very well with what the edge of the continent here is now known to look like. There is one relatively new point. Bellingshausen's first sighting has been moved forward one day, from the 28th to the 27th, because it has been shown that he was keeping ship's time, from mid-day to mid-day, and therefore that what his log called the 28th (his sighting being in the second half of the day) was what the civil calendar would call the 27th (Belov, 1963, p 19–29). All this much is well documented and unlikely to be disputed. The question is, how much importance did he, and his contemporaries, attach to this discovery? And did he realize that he had seen the edge of a continent? Recent Soviet studies have sought to show that he had a very good idea of the importance of what he had seen, and that this idea did get through to his contemporaries. It is here that there is room for argument with the Soviet scholars.

scholarly journals On the Long-Term Climate Memory in the Surface Air Temperature Records over Antarctica: A Nonnegligible Factor for Trend Evaluation

2015 ◽  
Vol 28 (15) ◽  
pp. 5922-5934 ◽  
Author(s):  
Naiming Yuan ◽  
Minghu Ding ◽  
Yan Huang ◽  
Zuntao Fu ◽  
Elena Xoplaki ◽  
...  
Keyword(s):  
White Noise ◽  
Surface Air Temperature ◽  
Fluctuation Analysis ◽  
The West ◽  
Weather System ◽  
Air Temperatures ◽  
Antarctic Continent ◽  
Temperature Records ◽  
The Antarctic

Abstract In this study, observed temperature records of 12 stations from Antarctica island, coastline, and continental areas are analyzed by means of detrended fluctuation analysis (DFA). After Monte Carlo significance tests, different long-term climate memory (LTM) behaviors are found: temperatures from coastal and island stations are characterized by significant long-term climate memory whereas temperatures over the Antarctic continent behave more like white noise, except for the Byrd station, which is located in the West Antarctica. It is argued that the emergence of LTM may be dominated by the interactions between local weather system and external slow-varying systems (ocean), and therefore the different LTM behaviors between temperatures over the Byrd station and that over other continental stations can be considered as a reflection of the different climatic environments between West and East Antarctica. By calculating the trend significance with the effect of LTM taken into account, and further comparing the results with those obtained from assumptions of autoregressive (AR) process and white noise, it is found that 1) most of the Antarctic stations do not show any significant trends over the past several decades, and 2) more rigorous trend evaluation can be obtained if the effect of LTM is considered. Therefore, it is emphasized that for air temperatures over Antarctica, especially for the Antarctica coastline, island, and the west continental areas, LTM is nonnegligible for trend evaluation.

scholarly journals Contribution of Land Use Changes to Near-Surface Air Temperatures during Recent Summer Extreme Heat Events in the Phoenix Metropolitan Area

2010 ◽  
Vol 49 (8) ◽  
pp. 1649-1664 ◽  
Author(s):  
Susanne Grossman-Clarke ◽  
Joseph A. Zehnder ◽  
Thomas Loridan ◽  
C. Sue B. Grimmond
Keyword(s):  
Land Use ◽  
Urban Development ◽  
Metropolitan Area ◽  
Extreme Temperatures ◽  
Near Surface ◽  
Lulc Changes ◽  
Extreme Heat Events ◽  
Air Temperatures ◽  
Nighttime Temperatures ◽  
Heat Events

Abstract The impact of 1973–2005 land use–land cover (LULC) changes on near-surface air temperatures during four recent summer extreme heat events (EHEs) are investigated for the arid Phoenix, Arizona, metropolitan area using the Weather Research and Forecasting Model (WRF) in conjunction with the Noah Urban Canopy Model. WRF simulations were carried out for each EHE using LULC for the years 1973, 1985, 1998, and 2005. Comparison of measured near-surface air temperatures and wind speeds for 18 surface stations in the region show a good agreement between observed and simulated data for all simulation periods. The results indicate consistent significant contributions of urban development and accompanying LULC changes to extreme temperatures for the four EHEs. Simulations suggest new urban developments caused an intensification and expansion of the area experiencing extreme temperatures but mainly influenced nighttime temperatures with an increase of up to 10 K. Nighttime temperatures in the existing urban core showed changes of up to ∼2 K with the ongoing LULC changes. Daytime temperatures were not significantly affected where urban development replaced desert land (increase by ∼1 K); however, maximum temperatures increased by ∼2–4 K when irrigated agricultural land was converted to suburban development. According to the model simulations, urban landscaping irrigation contributed to cooling by 0.5–1 K in maximum daytime as well as minimum nighttime 2-m air temperatures in most parts of the urban region. Furthermore, urban development led to a reduction of the already relatively weak nighttime winds and therefore a reduction in advection of cooler air into the city.

scholarly journals Temperature and Wind Climate of the Antarctic Peninsula as Simulated by a High-Resolution Regional Atmospheric Climate Model

2015 ◽  
Vol 28 (18) ◽  
pp. 7306-7326 ◽  
Author(s):  
Jan Melchior van Wessem ◽  
Carleen H. Reijmer ◽  
Willem Jan van de Berg ◽  
Michiel R. van den Broeke ◽  
Alison J. Cook ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Temperature ◽  
Antarctic Peninsula ◽  
Climate Model ◽  
Katabatic Wind ◽  
Near Surface ◽  
Climate Gradients ◽  
Climate Maps ◽  
The Antarctic ◽  
Regional Atmospheric Climate Model

Abstract The latest polar version of the Regional Atmospheric Climate Model (RACMO2.3) has been applied to the Antarctic Peninsula (AP). In this study, the authors present results of a climate run at 5.5 km for the period 1979–2013, in which RACMO2.3 is forced by ERA-Interim atmospheric and ocean surface fields, using an updated AP surface topography. The model results are evaluated with near-surface temperature and wind measurements from 12 manned and automatic weather stations and vertical profiles from balloon soundings made at three stations. The seasonal cycle of near-surface temperature and wind is simulated well, with most biases still related to the limited model resolution. High-resolution climate maps of temperature and wind showing that the AP climate exhibits large spatial variability are discussed. Over the steep and high mountains of the northern AP, large west-to-east climate gradients exist, while over the gentle southern AP mountains the near-surface climate is dominated by katabatic winds. Over the flat ice shelves, where katabatic wind forcing is weak, interannual variability in temperature is largest. Finally, decadal trends of temperature and wind are presented, and it is shown that recently there has been distinct warming over the northwestern AP and cooling over the rest of the AP, related to changes in sea ice cover.

scholarly journals Drifting snow statistics from multiple-year autonomous measurements in Adelie Land, eastern Antarctica

2019 ◽  
Author(s):  
Charles Amory
Keyword(s):  
Temporal Frequency ◽  
Field Measurements ◽  
Near Surface ◽  
Continental Scale ◽  
Drifting Snow ◽  
Single Location ◽  
Antarctic Continent ◽  
Short Time ◽  
The Antarctic ◽  
Snow Transport

Abstract. Drifting snow is a widespread feature over the Antarctic ice sheet whose climatological and hydrological significances at the continental scale have been consequently investigated through modelling and satellite approaches. While field measurements are needed to evaluate and interpret model and punctual satellite products, most drifting snow observation campaigns in Antarctica involved data collected at a single location and over short time periods. With the aim of acquiring new data relevant to the observations and modelling of drifting snow in Antarctic conditions, two remote locations in coastal Adelie Land (East Antarctica) 100 km apart were instrumented in January 2010 with meteorological and second-generation IAV Engineering acoustic FlowCaptTM sensors. The data provided nearly continuously so far constitutes the longest dataset of autonomous near-surface (i.e., below 2 m) measurements of drifting snow currently available over the Antarctic continent. This paper presents an assessment of drifting snow occurrences and snow mass transport from up to 9 years (2010–2018) of half-hourly observational records collected in one of the Antarctic regions most prone to snow transport by wind. The dataset is freely available to the scientific community and can be used to complement satellite products and evaluate snow-transport models close to the surface and at high temporal frequency.

Sign in / Sign up

Export Citation Format

Share Document