Radio weather transmissions in the Antarctic

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.

2009 ◽  
pp. 428-440
Author(s):  
V. F. Martazinova ◽  
◽  
V.S. Maderich ◽  
V. Y. Tymofeyev ◽  
E. K. Ivanova ◽  
...  

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.


2016 ◽  
Vol 16 (14) ◽  
pp. 9381-9397 ◽  
Author(s):  
Lars Hoffmann ◽  
Alison W. Grimsdell ◽  
M. Joan Alexander

Abstract. Stratospheric gravity waves from small-scale orographic sources are currently not well-represented in general circulation models. This may be a reason why many simulations have difficulty reproducing the dynamical behavior of the Southern Hemisphere polar vortex in a realistic manner. Here we discuss a 12-year record (2003–2014) of stratospheric gravity wave activity at Southern Hemisphere orographic hotspots as observed by the Atmospheric InfraRed Sounder (AIRS) aboard the National Aeronautics and Space Administration's (NASA) Aqua satellite. We introduce a simple and effective approach, referred to as the “two-box method”, to detect gravity wave activity from infrared nadir sounder measurements and to discriminate between gravity waves from orographic and other sources. From austral mid-fall to mid-spring (April–October) the contributions of orographic sources to the observed gravity wave occurrence frequencies were found to be largest for the Andes (90 %), followed by the Antarctic Peninsula (76 %), Kerguelen Islands (73 %), Tasmania (70 %), New Zealand (67 %), Heard Island (60 %), and other hotspots (24–54 %). Mountain wave activity was found to be closely correlated with peak terrain altitudes, and with zonal winds in the lower troposphere and mid-stratosphere. We propose a simple model to predict the occurrence of mountain wave events in the AIRS observations using zonal wind thresholds at 3 and 750 hPa. The model has significant predictive skill for hotspots where gravity wave activity is primarily due to orographic sources. It typically reproduces seasonal variations of the mountain wave occurrence frequencies at the Antarctic Peninsula and Kerguelen Islands from near zero to over 60 % with mean absolute errors of 4–5 percentage points. The prediction model can be used to disentangle upper level wind effects on observed occurrence frequencies from low-level source and other influences. The data and methods presented here can help to identify interesting case studies in the vast amount of AIRS data, which could then be further explored to study the specific characteristics of stratospheric gravity waves from orographic sources and to support model validation.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8268
Author(s):  
Sarah N. Davis ◽  
Christopher R. Torres ◽  
Grace M. Musser ◽  
James V. Proffitt ◽  
Nicholas M.A. Crouch ◽  
...  

The middle–late Eocene of Antarctica was characterized by dramatic change as the continent became isolated from the other southern landmasses and the Antarctic Circumpolar Current formed. These events were crucial to the formation of the permanent Antarctic ice cap, affecting both regional and global climate change. Our best insight into how life in the high latitudes responded to this climatic shift is provided by the fossil record from Seymour Island, near the eastern coast of the Antarctic Peninsula. While extensive collections have been made from the La Meseta and Submeseta formations of this island, few avian taxa other than penguins have been described and mammalian postcranial remains have been scarce. Here, we report new fossils from Seymour Island collected by the Antarctic Peninsula Paleontology Project. These include a mammalian metapodial referred to Xenarthra and avian material including a partial tarsometatarsus referred to Gruiformes (cranes, rails, and allies). Penguin fossils (Sphenisciformes) continue to be most abundant in new collections from these deposits. We report several penguin remains including a large spear-like mandible preserving the symphysis, a nearly complete tarsometatarsus with similarities to the large penguin clade Palaeeudyptes but possibly representing a new species, and two small partial tarsometatarsi belonging to the genus Delphinornis. These findings expand our view of Eocene vertebrate faunas on Antarctica. Specifically, the new remains referred to Gruiformes and Xenarthra provide support for previously proposed, but contentious, earliest occurrence records of these clades on the continent.


2020 ◽  
Vol 14 (10) ◽  
pp. 3551-3564
Author(s):  
Suzanne Bevan ◽  
Adrian Luckman ◽  
Harry Hendon ◽  
Guomin Wang

Abstract. Along with record-breaking summer air temperatures at an Antarctic Peninsula meteorological station in February 2020, the Larsen C ice shelf experienced an exceptionally long and extensive 2019/2020 melt season. We use a 40-year time series of passive and scatterometer satellite microwave data, which are sensitive to the presence of liquid water in the snow pack, to reveal that the extent and duration of melt observed on the ice shelf in the austral summer of 2019/2020 was the greatest on record. We find that unusual perturbations to Southern Hemisphere modes of atmospheric flow, including a persistently positive Indian Ocean Dipole in the spring and a very rare Southern Hemisphere sudden stratospheric warming in September 2019, preceded the exceptionally warm Antarctic Peninsula summer. It is likely that teleconnections between the tropics and southern high latitudes were able to bring sufficient heat via the atmosphere and ocean to the Antarctic Peninsula to drive the extreme Larsen C Ice Shelf melt. The record-breaking melt of 2019/2020 brought to an end the trend of decreasing melt that had begun in 1999/2000, will reinitiate earlier thinning of the ice shelf by depletion of the firn air content, and probably affected a much greater region than Larsen C Ice Shelf.


2021 ◽  
Author(s):  
Irina Gorodetskaya ◽  
Penny Rowe ◽  
Heike Kalesse ◽  
Patric Seifert ◽  
Sang-Jong Park ◽  
...  

<p>During the last several decades, the Antarctic Peninsula (AP) has shown a much stronger warming trend compared to the rest of the ice sheet and other land areas in the Southern Hemisphere (Jones et al, 2019). Recent studies have also highlighted that the AP has experienced both an increase in precipitation and in surface melt. Atmospheric rivers (ARs) – long corridors of intense moisture transport from subtropical and mid-latitude regions poleward - are known for prominent role in moisture transport (Gorodetskaya et al, 2020) and intense precipitation in Antarctica (Gorodetskaya et al 2014). At the same time, ARs have been also associated with major surface melt events at the AP and adjacent ice shelves (Wille et al 2019). In this study, we explore the double role of ARs, as carriers of both heat and moisture, in their impacts on precipitation (rain and snow), cloud radiative forcing and air temperature at the AP. Observations from the Year of Polar Prediction (YOPP, Bromwich et al 2020) endorsed sites/projects are used: Escudero station (the Characterization of the Antarctic Atmosphere and Low Clouds, or CAALC project) and King Sejong station (South Korean Antarctic Program projects) on King George Island, as well as Punta Arenas (southern Chile; the Dynamics, Aerosol, Cloud, And Precipitation Observations in the Pristine Environment of the Southern Ocean, or DACAPO-PESO project). These projects employed a set of ground-based remote sensing instrumentation for water vapor, cloud and precipitation observations, as well as frequent radiosonde launches during the YOPP Special Observing Period in austral summer 2018/2019. We present case studies characterizing the temporal evolution of ARs, focusing on thermodynamic and dynamic conditions accompanying the transition between snowfall and rain. Further, we demonstrate the added value of assimilating more frequent radiosonde observations in improving the forecast of weather conditions during ARs using the Polar-WRF model, including wind and precipitation prediction, which have important consequences for air, ship and station operations in Antarctica.</p><p>Bromwich, D. H., K. Werner, B. Casati, J. G. Powers, I. V. Gorodetskaya, F. Massonnet, V. Vitale, et al: The Year of Polar Prediction in the Southern Hemisphere (YOPP-SH), Bull. Amer. Meteor. Soc., doi: https://doi.org/10.1175/BAMS-D-19-0255.1.</p><p>Gorodetskaya, I.V., Silva, T., Schmithüsen, H., and Hirasawa, N., 2020: Atmospheric River Signatures in Radiosonde Profiles and Reanalyses at the Dronning Maud Land Coast, East Antarctica.Adv. Atmos. Sci., https://doi.org/10.1007/s00376-020-9221-8</p><p>Gorodetskaya, I. V., M. Tsukernik, K. Claes, M. F. Ralph, W. D. Neff, and N. P. M. van Lipzig, 2014: The role of atmospheric rivers in anomalous snow accumulation in East Antarctica. Geophys. Res. Lett.,  https://doi.org/10.1002/2014GL060881</p><p>Jones, M. E., Bromwich, D. H., Nicolas, J. P., Carrasco, J., Plavcova, E., Zou, X., & Wang, A. S.-H. (2019). Sixty Years of Widespread Warming in the Southern Middle and High Latitudes (1957-2016). J. Climate, https://doi.org/10.1175/JCLI-D-18</p><p>Wille, J.D., Favier, V., Dufour, A., Gorodetskaya, I.V., Turner, J., Agosta, C., and Codron, F., 2019. West Antarctic surface melt triggered by atmospheric rivers. Nat. Geosci. https://doi.org/10.1038/s41561-019-0460-1</p>


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

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