scholarly journals The ultraviolet radiation environment during an expedition across the Drake Passage and on the Antarctic Peninsula

2014 ◽  
Vol 27 (3) ◽  
pp. 307-316 ◽  
Author(s):  
Andrew Russell ◽  
Manmohan Gohlan ◽  
Andrew Smedley ◽  
Martin Densham

AbstractPolysulphone ultraviolet dosimetry badges were deployed daily during a British Services Antarctic Expedition to the Antarctic Peninsula, including a cruise period across the Drake Passage. The expedition was undertaken from 20 December 2011 to 7 March 2012. Badges were successfully analysed from 46 days of the expedition with a daily mean of 1.8 kJ m-2 erythemal daily dose (EDD) and a range of 0.3–4.3 kJ m-2 EDD. The results indicate that the ultraviolet EDD experienced was comparable to temperate, mid-latitude locations in the spring/late summer. The variability of the badge measurements was mostly consistent with observations from a local ground-based radiometer and equivalent satellite-derived products. However, such comparisons are limited by the changing location/altitude of the expedition and known biases in the satellite data. This highlights that the new dataset of exposure experienced at the Antarctic surface complements those produced by stationary ground-based instruments or satellites and, therefore, that the badge dataset brings a new element to this issue. The highest EDD values during the expedition occurred at high altitude, and the lowest EDD values occurred at low altitude and high latitude with relatively high total ozone column concentration.

2021 ◽  
Vol 13 (8) ◽  
pp. 1594
Author(s):  
Songkang Kim ◽  
Sang-Jong Park ◽  
Hana Lee ◽  
Dha Hyun Ahn ◽  
Yeonjin Jung ◽  
...  

The ground-based ozone observation instrument, Brewer spectrophotometer (Brewer), was used to evaluate the quality of the total ozone column (TOC) produced by multiple polar-orbit satellite measurements at three stations in Antarctica (King Sejong, Jang Bogo, and Zhongshan stations). While all satellite TOCs showed high correlations with Brewer TOCs (R = ~0.8 to 0.9), there are some TOC differences among satellite data in austral spring, which is mainly attributed to the bias of Atmospheric Infrared Sounder (AIRS) TOC. The quality of satellite TOCs is consistent between Level 2 and 3 data, implying that “which satellite TOC is used” can induce larger uncertainty than “which spatial resolution is used” for the investigation of the Antarctic TOC pattern. Additionally, the quality of satellite TOC is regionally different (e.g., OMI TOC is a little higher at the King Sejong station, but lower at the Zhongshan station than the Brewer TOC). Thus, it seems necessary to consider the difference of multiple satellite data for better assessing the spatiotemporal pattern of Antarctic TOC.


1997 ◽  
Vol 9 (4) ◽  
pp. 443-444 ◽  
Author(s):  
R.A. del Valle ◽  
J.M. Lirio ◽  
J.C. Lusky ◽  
J.R. Morelli ◽  
H.J. Nuñez

Jason Peninsula (66°10'S, 61°00'W) is a prominent feature extending some 80 km into the Larsen Ice Shelf from the eastern coast of the Antarctic Peninsula, and consists of widely spaced rock exposures and several ice-domes with elevations up to some 600 m (Fig. 1). The feature was first seen from seaward on 1 December 1893 by Captain C.A. Larsen, who named one of the high summits “Mount Jason” after his ship. Leading the 1902–1904 Swedish Antarctic Expedition, Dr Otto Nordenskjöld observed the area from Borchgrevink Nunatak (66°03'S; 62°30'W) and reported that the summits seen by Larsen were separated from the Antarctic Peninsula. The name “Jason Island” was subsequently adopted for this feature, but in the 1950s researchers belonging to the currently named British Antarctic Survey (BAS) determined Larsen's discovery to be a large peninsula, underlain mainly by calc-alkaline volcanic rocks.


2021 ◽  
Vol 21 (2) ◽  
pp. 617-633
Author(s):  
Martin Dameris ◽  
Diego G. Loyola ◽  
Matthias Nützel ◽  
Melanie Coldewey-Egbers ◽  
Christophe Lerot ◽  
...  

Abstract. Ozone data derived from the Tropospheric Monitoring Instrument (TROPOMI) sensor on board the Sentinel-5 Precursor satellite show exceptionally low total ozone columns in the polar region of the Northern Hemisphere (Arctic) in spring 2020. Minimum total ozone column values around or below 220 Dobson units (DU) were seen over the Arctic for 5 weeks in March and early April 2020. Usually the persistence of such low total ozone column values in spring is only observed in the polar Southern Hemisphere (Antarctic) and not over the Arctic. These record low total ozone columns were caused by a particularly strong polar vortex in the stratosphere with a persistent cold stratosphere at higher latitudes, a prerequisite for ozone depletion through heterogeneous chemistry. Based on the ERA5, which is the fifth generation of the European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis, the Northern Hemisphere winter 2019/2020 (from December to March) showed minimum polar cap temperatures consistently below 195 K around 20 km altitude, which enabled enhanced formation of polar stratospheric clouds. The special situation in spring 2020 is compared and discussed in context with two other Northern Hemisphere spring seasons, namely those in 1997 and 2011, which also displayed relatively low total ozone column values. However, during these years, total ozone columns below 220 DU over several consecutive days were not observed in spring. The similarities and differences of the atmospheric conditions of these three events and possible explanations for the observed features are presented and discussed. It becomes apparent that the monthly mean of the minimum total ozone column value for March 2020 (221 DU) was clearly below the respective values found in March 1997 (267 DU) and 2011 (252 DU), which highlights the special evolution of the polar stratospheric ozone layer in the Northern Hemisphere in spring 2020. A comparison with a typical ozone hole over the Antarctic (e.g., in 2016) indicates that although the Arctic spring 2020 situation is remarkable, with total ozone column values around or below 220 DU observed over a considerable area (up to 0.9 million km2), the Antarctic ozone hole shows total ozone columns typically below 150 DU over a much larger area (of the order of 20 million km2). Furthermore, total ozone columns below 220 DU are typically observed over the Antarctic for about 4 months.


Polar Record ◽  
1991 ◽  
Vol 27 (161) ◽  
pp. 103-114 ◽  
Author(s):  
Rubens J. Villela

AbstractDuring seven summer Brazilian expeditions to the Antarctic Peninsula area the author used radio weather transmissions to collect data for synoptic analysis and operational weather forecasting. A particularly intensive effort aboard Barão de Teffé in 1989–90 yielded detailed information on frequencies, schedules, procedures and contents, which should be useful to radio-operators, meteorologists, and other Antarctic workers since official publications listing Antarctic radio transmissions are out-dated or incomplete. Radiotelegraph broadcasts particularly valuable to mariners, which may replace or complement facsimile transmissions, are made by Valparaiso, Punta Arenas, and Buenos Aires. Because of unreliable reception of regular fax and teletype broadcasts, synoptic reports were copied directly by monitoring voice and Morse point-to-point circuits, gaining time crucial to operational decisions. Especially useful sources of reports were the Frei, Marambio, and Faraday collections, and the USSR radiotelegraph communications carrying land and ship reports for all sectors of Antarctica and southern hemisphere oceans. Other signals, eg from Chilean lighthouses, ships of opportunity, and aircraft have become useful sources of meteorological information, especially for Drake Passage since Chile has suspended broadcasts, adversely affecting weather forecasting in the area. An insight into weather conditions on the Antarctic Plateau, as well as a sense of history in the making, were gained by monitoring Adventure Network International's radio frequencies.


2019 ◽  
Author(s):  
Kaisa Lakkala ◽  
Margit Aun ◽  
Ricardo Sanchez ◽  
Germar Bernhard ◽  
Eija Asmi ◽  
...  

Abstract. A GUV multifilter radiometer was set up at Marambio, 64° S 56° W, Antarctica, in 2017. The instrument measures continuously ultraviolet (UV) radiation, visible (VIS) radiation and photosynthetically active radiation (PAR). The measurements are designed for providing high quality long-term time series which can be used to assess the impact of global climate change in the Antarctic region. The quality assurance includes regular absolute calibrations and solar comparisons performed at the site and at Sodankylä, Finland. The actual measurements continue the time series measured at Marambio with NILU-UV radiometers during 2000–2010 as part of the Antarctic NILU-UV network. They are optimal for assessing the effects of the ongoing stratospheric ozone recovery on the ecosystem as the data products include information on radiation at various wavelengths ranging from UV to VIS so that changes on biologically effective radiation due to ozone can be separated from those due to other factors. The final data products are total ozone, PAR, VIS radiation at 555 nm, UV index, UV irradiance at 5 channels, UVB and UVA dose rate/daily dose, and biologically weighted UV dose rate/ daily dose, including 10 different action spectra. The data from the last five days and the daily maximum UV index time series are plotted and updated daily on the web page fmiarc.fmi.fi/sub_sites/GUVant/. The first two years of UV measurements were very different in terms of the results: The monthly average of daily maximum UVB dose rates were clearly higher in 2018 than in 2017 during the period from October to December. The largest difference was observed in October, when the average of daily maximum UVB dose rates was 7.6 kWm−2 and 10.2 kWm−2 in 2017 and 2018, respectively. The monthly averages were close to each other for all the three months in 2018, while in 2017 the monthly average of October was lower than those of November and December. VIS and PAR time series show that daily maxima in 2018–2019 exceed those in 2017–2018 during the late spring and the summer (mid-November–January). The studied dataset is freely accessible at https://doi.org/10.5281/zenodo.3553634 (Lakkala et al.,2019).


2021 ◽  
Author(s):  
Le Cao ◽  
Linjie Fan ◽  
Simeng Li ◽  
Shuangyan Yang

Abstract. The occurrence of the tropospheric ozone depletion events (ODEs) in the Antarctic can be influenced by the change in Total Ozone Column (TOC). In this study, we combined the observational data obtained from ground observation stations with two numerical models (TUV and KINAL), to figure out the relationship between the TOC change and the occurrence of ODEs in the Antarctic. A sensitivity analysis was also performed on the change in ozone and major bromine species (BrO, HOBr and HBr) to find out key photolysis reactions determining the impact on the occurrence of tropospheric ODEs brought by the change in TOC. From the analysis of the observational data and the numerical results, we suggested that the occurrence frequency of ODEs in the Antarctic seems negatively correlated with the variation of TOC. Moreover, major ODE accelerating reactions (i.e. photolysis of ozone, H2O2 and HCHO) and decelerating reactions (i.e. photolysis of BrO and HOBr), which heavily control the start of ODEs, were also identified. It was found that when TOC varies, the major ODE accelerating reactions speed up significantly, while major ODE decelerating reactions are only slightly affected, thus leading to the negative dependence of the ODE occurrence on the change in TOC.


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