CHRISTIAN HJORT, ÓLAFUR INGÓLFSSON AND Straddling the Drake Passage: A summary of Otto Nordenskjöld’s and his geological co-worker’s achievements in Patagonia, Tierra del Fuego and 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.


2020 ◽  
Author(s):  
Markus Rapp ◽  
Bernd Kaifler ◽  
Andreas Dörnbrack ◽  
Sonja Gisinger ◽  
Tyler Mixa ◽  
...  

<p>The region around Southern Argentina and the Antarctic peninsula is known as the world’s strongest hotspot of stratospheric gravity wave activity. In this region, large tropospheric winds are perturbed by the orography of the Andes and the Antarctic peninsula resulting in the excitation of mountain waves which might propagate all the way up into the upper mesosphere when the polar night jet is intact. In addition, satellite observations also show large stratospheric wave activity in the region of the Drake passage, i.e., in between the Andes and the Antarctic peninsula, and along the corresponding latitudinal circle of 60°S. The origin of these waves is currently not entirely understood. Several hypotheses are currently being investigated, like for example the idea that the mountain waves that were originally excited over the Andes and the Antarctic peninsula propagate horizontally to 60°S and along the latitudinal circle. In order to investigate this and other hypotheses the German research aircraft HALO was deployed to Rio Grande, Tierra del Fuego, at the Southern Tip of Argentina in September and November 2019 in the frame of the SOUTHTRAC (Southern hemisphere Transport, Dynamics, and Chemistry) research mission. A total of 6 dedicated research flights with a typical length of 7000km were conducted to obtain gravity wave observations with the newly developed ALIMA (ALIMA=Airborne LIdar for Middle Atmosphere research)-instrument and the GLORIA (GLORIA=Gimballed Limb Observer for Radiance Imaging of the Atmosphere) limb sounder. While ALIMA measures temperatures and temperature perturbations in the altitude range from 20-90 km, GLORIA observations allow to characterize wave perturbations in temperatures and trace gas concentrations below flight level (<~14 km). This paper gives an overview of the mission objectives, the prevailing atmospheric conditions during the HALO deployment, and highlights some outstanding initial results of the gravity wave observations.</p>


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.


2012 ◽  
Vol 117 (D2) ◽  
pp. n/a-n/a ◽  
Author(s):  
A. de la Torre ◽  
P. Alexander ◽  
R. Hierro ◽  
P. Llamedo ◽  
A. Rolla ◽  
...  

2000 ◽  
Vol 27 (1) ◽  
pp. 69
Author(s):  
EDGARDO MARTÍN GELOS ◽  
JORGE OSVALDO SPAGNUOLO ◽  
FEDERICO IGNACIO ISLA

Sand mineralogical analysis from 22 beaches were performed within the southernmost area of Argentina (Isla Grande de Tierra del Fuego), the Antarctic Peninsula and the Scotia Arc (South Orkney, South Shetland and James Ross islands included). Composition triangles of light and heavy minerals were considered in order to relate them to depocenters, sediment sources and tectonic setting. 71% of the sediments would have been transported from magmatic arcs, 24% from elevated crystalline basements and only 5% from recycled orogene. In regard to the heavy mineral distribution, 70% were assigned to a suite from an active continental margin and the remaining 30% would correspond to areas outside the continental margins (volcanic arcs). In a general way, sediment sources were related to active margins or volcanic island arcs. As an anomalous fact, it is stressed that the coasts of Tierra del Fuego and the western sector of the Antarctic Peninsula and adjacent islands, contain sediments from a Pacific margin but lying on a passive Atlantic margin. Finally, it should be adviced about the convenience to know the source areas when ice is the transport agent, as it avoids a selective ability and it does not modify the original mineralogical composition.


Sign in / Sign up

Export Citation Format

Share Document