Regional and Large-Scale Influences on Antarctic Peninsula Climate

Southern Ocean ecosystems are rapidly changing due to climate variability. An apparent beneficiary of such change in the western Antarctic Peninsula (WAP) is the gentoo penguin Pygoscelis papua , which has increased its population size and expanded its range southward in the last 20 years. To better understand how this species has responded to large-scale changes, we tracked individuals during the non-breeding winter period from five colonies across the latitudinal range of breeding sites in the WAP, including from a recently established colony. Results highlight latitudinal gradients in movement; strong associations with shallow, coastal habitats along the entire Antarctic Peninsula; and movements that are independent of, yet constrained by, sea ice. It is clear that coastal habitats essential to gentoo penguins during the breeding season are similarly critical during winter. Larger movements of birds from northern colonies in the WAP further suggest that leap-frog migration may influence colonization events by facilitating nest-area prospecting and use of new haul-out sites. Our results support efforts to develop a marine protected area around the WAP. Winter habitats used by gentoo penguins outline high priority areas for improving the management of the spatio-temporally concentrated krill ( Euphausia superba ) fishery that operates in this region during winter.

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Antarctic Peninsula warming and precipitation phase transition during atmospheric river events

10.5194/dach2022-309 ◽

2021 ◽

Author(s):

Irina Gorodetskaya ◽

Penny Rowe ◽

Xun Zou ◽

Anastasia Chyhareva ◽

Svitlana Krakovska ◽

...

Keyword(s):

Phase Transition ◽

Antarctic Peninsula ◽

Moisture Transport ◽

Large Scale ◽

The Arctic ◽

Polar Regions ◽

Near Surface ◽

Depth Analysis ◽

Heat And Moisture ◽

Precipitation Phase

Polar amplification has been pronounced in the Arctic with near-surface air temperatures increasing at more than twice the global warming rate during the last several decades. At the same time, over Antarctica temperature trends have exhibited a large regional variability. In particular, the Antarctic Peninsula (AP) stands out as having a warming rate much higher than the rest of the Antarctic ice sheet and other land areas in the Southern Hemisphere (SH). Future projections indicate that warming and ice loss will intensify in both polar regions with important impacts globally. In addition to the warming amplification, there has been also an enhancement of the polar water cycle with increases in poleward moisture transport and precipitation in both polar regions. An important process linking warming and precipitation enhancement is a shift towards more frequent rainfall compared to snowfall. Future projections show that the rain fraction will significantly increase in coastal Antarctica, especially in the AP. Atmospheric rivers (ARs), long corridors of intense moisture transport from subtropical and mid-latitude regions poleward, are known for their prominent role in both heat and moisture transport with impacts ranging from intense precipitation to temperature records and major melt events in Antarctica. Limited observations have hampered process understanding and correct representation of these extreme events in models. This presentation will give an overview of the enhanced observations targeting ARs in the AP (including surface meteorology, radiosonde, cloud and precipitation remote sensing, and radiative fluxes) as part of the Year of Polar Prediction (YOPP)-SH international collaborative effort. In-depth analysis of transport of heat and moisture, atmospheric vertical structure, cloud properties and precipitation phase transition from snowfall to rainfall during selected AR cases will be presented and compared with ERA5 reanalysis and high-resolution Polar-WRF model simulations. We will highlight three different local regimes around the AP: large-scale precipitation over the Southern Ocean north of the AP, orographic enhancement of precipitation in the western AP and the role of foehn, cloud/precipitation clearing and temperature increase in the northeastern AP.

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Temperature Change on the Antarctic Peninsula Linked to the Tropical Pacific*

Journal of Climate ◽

10.1175/jcli-d-12-00729.1 ◽

2013 ◽

Vol 26 (19) ◽

pp. 7570-7585 ◽

Cited By ~ 56

Author(s):

Qinghua Ding ◽

Eric J. Steig

Keyword(s):

Sea Ice ◽

Antarctic Peninsula ◽

Large Scale ◽

Wave Train ◽

Warming Trend ◽

Tropical Pacific ◽

The West ◽

Spring Warming ◽

Western Side ◽

The Antarctic

Abstract Significant summer warming over the eastern Antarctic Peninsula in the last 50 years has been attributed to a strengthening of the circumpolar westerlies, widely believed to be anthropogenic in origin. On the western side of the peninsula, significant warming has occurred mainly in austral winter and has been attributed to the reduction of sea ice. The authors show that austral fall is the only season in which spatially extensive warming has occurred on the Antarctic Peninsula. This is accompanied by a significant reduction of sea ice cover off the west coast. In winter and spring, warming is mainly observed on the west side of the peninsula. The most important large-scale forcing of the significant widespread warming trend in fall is the extratropical Rossby wave train associated with tropical Pacific sea surface temperature anomalies. Winter and spring warming on the western peninsula reflects the persistence of sea ice anomalies arising from the tropically forced atmospheric circulation changes in austral fall.

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Testing early life connectivity using otolith chemistry and particle-tracking simulations

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f10-065 ◽

2010 ◽

Vol 67 (8) ◽

pp. 1303-1315 ◽

Cited By ~ 25

Author(s):

Julian Ashford ◽

Mario La Mesa ◽

Bettina A. Fach ◽

Christopher Jones ◽

Inigo Everson

Keyword(s):

Antarctic Peninsula ◽

Early Life ◽

Large Scale ◽

Circulation Model ◽

Model Material ◽

Otolith Chemistry ◽

Larval Phase ◽

Scotia Sea ◽

South Georgia ◽

The Antarctic

We measured the otolith chemistry of adult Scotia Sea icefish ( Chaenocephalus aceratus ), a species with a long pelagic larval phase, along the Antarctic Circumpolar Current (ACC) and compared the chemistry with simulated particle transport using a circulation model. Material laid down in otolith nuclei during early life showed (i) strong heterogeneity between the Antarctic Peninsula and South Georgia consistent with a population boundary, (ii) evidence of finer-scale heterogeneity between sampling areas on the Antarctic Peninsula, and (iii) similarity between the eastern and northern shelves of South Georgia, indicating a single, self-recruiting population there. Consistent with the otolith chemistry, simulations of the large-scale circulation predicted that particles released at depths of 100–300 m on the Antarctic Peninsula shelf during spring, corresponding to hatching of icefish larvae from benthic nests, are transported in the southern ACC, missing South Georgia but following trajectories along the southern Scotia Ridge instead. These results suggest that the timing of release and position of early life stages in the water column substantially influence the direction and extent of connectivity. Used in complement, the two techniques promise an innovative approach for generating and testing predictions to resolve early dispersal and connectivity of populations related to the physical circulation of oceanic systems.

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Interpopulational differences in the nutritional condition of Aequiyoldia eightsii (Protobranchia: Nuculanidae) from the Western Antarctic Peninsula during austral summer

PeerJ ◽

10.7717/peerj.12679 ◽

2021 ◽

Vol 9 ◽

pp. e12679

Author(s):

Miguel Bascur ◽

Simon A. Morley ◽

Michael P. Meredith ◽

Carlos P. Muñoz-Ramírez ◽

David K. A. Barnes ◽

...

Keyword(s):

Fatty Acids ◽

Antarctic Peninsula ◽

Large Scale ◽

Energy Content ◽

Seawater Temperature ◽

Austral Summer ◽

Nutritional Condition ◽

Research Station ◽

Western Antarctic Peninsula ◽

The North

The Western Antarctic Peninsula (WAP) is a hotspot for environmental change and has a strong environmental gradient from North to South. Here, for the first time we used adult individuals of the bivalve Aequiyoldia eightsii to evaluate large-scale spatial variation in the biochemical composition (measured as lipid, protein and fatty acids) and energy content, as a proxy for nutritional condition, of three populations along the WAP: O’Higgins Research Station in the north (63.3°S), Yelcho Research Station in mid-WAP (64.9°S) and Rothera Research Station further south (67.6°S). The results reveal significantly higher quantities of lipids (L), proteins (P), energy (E) and total fatty acids (FA) in the northern population (O’Higgins) (L: 8.33 ± 1.32%; P: 22.34 ± 3.16%; E: 171.53 ± 17.70 Joules; FA: 16.33 ± 0.98 mg g) than in the mid-WAP population (Yelcho) (L: 6.23 ± 0.84%; P: 18.63 ± 1.17%; E: 136.67 ± 7.08 Joules; FA: 10.93 ± 0.63 mg g) and southern population (Rothera) (L: 4.60 ± 0.51%; P: 13.11 ± 0.98%; E: 98.37 ± 5.67 Joules; FA: 7.58 ± 0.48 mg g). We hypothesize these differences in the nutritional condition could be related to a number of biological and environmental characteristics. Our results can be interpreted as a consequence of differences in phenology at each location; differences in somatic and gametogenic growth rhythms. Contrasting environmental conditions throughout the WAP such as seawater temperature, quantity and quality of food from both planktonic and sediment sources, likely have an effect on the metabolism and nutritional intake of this species.

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Cloud and precipitation microphysics evaluated with ERA-5 and Polar WRF over the northern Antarctic Peninsula

10.5194/egusphere-egu21-13058 ◽

2021 ◽

Author(s):

Anastasiia Chyhareva ◽

Svitlana Krakovska ◽

Irina Gorodetskaya ◽

Denis Pishniak ◽

Jonathan Wille ◽

...

Keyword(s):

Phase Transition ◽

Phase Transitions ◽

Antarctic Peninsula ◽

Large Scale ◽

Lower Troposphere ◽

Cloud Microphysics ◽

Orographic Enhancement ◽

Precipitation Type ◽

The Antarctic ◽

Precipitation Phase

Synoptic-scale atmospheric circulation that transports moisture from lower latitudes highly influences the Antarctic coastal climate, warming and moistening the lower troposphere and causing both precipitation and temperature increases. During recent decades, it has been shown that the highest warming rate over Antarctica is observed over the Antarctic Peninsula region. Heat and moisture transport from lower latitudes, particularly associated with atmospheric rivers (ARs), could play a crucial role in this warming. Among the most complex and understudied processes relate to microphysical properties of clouds and precipitation and understanding phase transitions during intense precipitation events associated with ARs and their representation in polar weather and climate models.The goal of this research is&#160; to investigate the temporal and spatial evolution of precipitation, including its intensity and phase transition and associated cloud properties during AR events over the Antarctic Peninsula in austral summer. We focus on two sites representing different regional and micro-climates around the Antarctic Peninsula - Escudero station, situated on King George Island at the northern tip of the peninsula, and Vernadsky station &#8211; located on Galindez Island at the western (upwind) side closer to the central part of the peninsula. Although both stations have typical maritime climate, the Vernadsky site is more affected by orographic enhancement of precipitation and cold air advection from the continent.We use ground-based observations of meteorology, conducted during The Year of Polar Prediction Special Observing Period (YOPP-SOP) in summer 2018/2019 over the Antarctic Peninsula region and compare against ERA-5 and AMPS Polar WRF. After evaluating ERA-5 reanalysis , it is used for large-scale analysis of clouds and precipitation type. The timings of precipitation phase transitions in ERA-5 and Polar WRF are determined for the grid cells where the two stations are located. Sensitivity to microphysics parameterization in Polar WRF is tested with several double moment cloud microphysics parameterization schemes.We analyze two cases with observed precipitation phase transitions, during the first week of December 2018. Higher precipitation amounts were observed over Vernadsky station during the first event and over Escudero during the second event. Total precipitation during the whole week is higher for Vernadsky station compared to Escudero station, related to the AR landfall position and strength, as well as the orographic enhancement at the upwind side of the Antarctic Peninsula ridge. This is confirmed by assessment of ERA-5 data. Comparison with the YOPP-SOP observations at Escudero shows that ERA-5 represents major precipitation type accurately and thus can be used for further study of precipitation microphysics. For Vernadsky station, ERA-5 showed a few cases of phase transition from snow to wet snow, associated with ARs events according to ERA-5 data; unfortunatly observations for comparison were lacking. Compared to ERA-5, Polar WRF shows a finer structure of precipitation fields disturbed by the mountains. We intend to test different parameterizations of cloud microphysics in Polar WRF with fine resolution against the complex of measurements at Vernadsky station in order to find the optimal configuration in the region to use during the upcoming winter YOPP in the Southern Hemisphere.

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Partial limb skeleton of a “giant penguin” Anthropornis from the Eocene of Antarctic Peninsula

Polish Polar Research ◽

10.2478/v10183-012-0017-0 ◽

2012 ◽

Vol 33 (3) ◽

pp. 259-274 ◽

Cited By ~ 20

Author(s):

Piotr Jadwiszczak

Keyword(s):

Antarctic Peninsula ◽

Fossil Record ◽

Large Scale ◽

Single Individual ◽

Antarctic Species ◽

Late Paleocene ◽

La Meseta Formation ◽

Functional Analyses ◽

The Antarctic

Abstract: The fossil record of the Antarctic penguins is dated to the late Paleocene of Sey− mour (Marambio) Island, but the largest sphenisciforms, generaAnthropornisandPalae−eudyptes, originate from the Eocene La Meseta Formation. Here, the most complete large−scale reconstruction of a limb skeleton (a whole wing and a partial hind leg) of a Paleogene Antarctic penguin is reported. All bones are attributable to a single individual identified asAnthropornissp. The comparative and functional analyses of the material indi− cate that this bird was most probably well−adapted to land and sea while having a number of intriguing features. The modern−grade carpometacarpal morphology is unique among known Eocene Antarctic species and all but one more northerly taxa.

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Large-scale dynamical influence of a gravity wave generated over the Antarctic Peninsula – regional modelling and budget analysis

Tellus A Dynamic Meteorology and Oceanography ◽

10.3402/tellusa.v65i0.20254 ◽

2013 ◽

Vol 65 (1) ◽

pp. 20254 ◽

Cited By ~ 2

Author(s):

JOEL Arnault

Keyword(s):

Gravity Wave ◽

Antarctic Peninsula ◽

Large Scale ◽

Regional Modelling ◽

Budget Analysis ◽

The Antarctic

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Firn air depletion as a precursor of Antarctic ice-shelf collapse

Journal of Glaciology ◽

10.3189/2014jog13j183 ◽

2014 ◽

Vol 60 (220) ◽

pp. 205-214 ◽

Cited By ~ 65

Author(s):

Peter Kuipers Munneke ◽

Stefan R.M. Ligtenberg ◽

Michiel R. Van Den Broeke ◽

David G. Vaughan

Keyword(s):

Porous Medium ◽

Hydrostatic Pressure ◽

Antarctic Peninsula ◽

Large Scale ◽

Pore Space ◽

Climate Scenario ◽

Low Density ◽

Ice Shelf ◽

Ice Shelves ◽

The Antarctic

AbstractSince the 1970s, the sudden, rapid collapse of 20% of ice shelves on the Antarctic Peninsula has led to large-scale thinning and acceleration of its tributary glaciers. The leading hypothesis for the collapse of most of these ice shelves is the process of hydrofracturing, whereby a water-filled crevasse is opened by the hydrostatic pressure acting at the crevasse tip. This process has been linked to observed atmospheric warming through the increased supply of meltwater. Importantly, the low-density firn layer near the ice-shelf surface, providing a porous medium in which meltwater can percolate and refreeze, has to be filled in with refrozen meltwater first, before hydrofracturing can occur at all. Here we build upon this notion of firn air depletion as a precursor of ice-shelf collapse, by using a firn model to show that pore space was depleted in the firn layer on former ice shelves, which enabled their collapse due to hydrofracturing. Two climate scenario runs with the same model indicate that during the 21st century most Antarctic Peninsula ice shelves, and some minor ice shelves elsewhere, are more likely to become susceptible to collapse following firn air depletion. If warming continues into the 22nd century, similar depletion will become widespread on ice shelves around East Antarctica. Our model further suggests that a projected increase in snowfall will protect the Ross and Filchner–Ronne Ice Shelves from hydrofracturing in the coming two centuries.

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Numerical Simulation of Sea Breeze Convergence over Antarctic Peninsula

Advances in Meteorology ◽

10.1155/2017/7686540 ◽

2017 ◽

Vol 2017 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Alcimoni Nelci Comin ◽

Otávio Costa Acevedo

Keyword(s):

Antarctic Peninsula ◽

Large Scale ◽

Potential Temperature ◽

Sensible Heat Flux ◽

Wrf Model ◽

Sea Breeze ◽

Circulation System ◽

Breeze Circulation ◽

Synoptic Wind ◽

Cold Anomaly

The convergence zone induced by sea breeze systems over Antarctic Peninsula is analyzed for the summer season of 2013–2015. 59 days, selected by satellite images for the absence of major synoptic forcing, are simulated using the WRF model. Sea breeze convergence has been detected in 21 of these days, mostly during evening hours and under large-scale winds. Breeze events are associated with a cold anomaly at the peninsula with respect to the climatology. This condition favors the onset of the necessary horizontal thermal gradients to trigger the breeze circulation. At the same time, no anomaly of the average pressure at sea level is found, indicating that events are favored when the average synoptic flow is present. Case studies indicate that the convergence location over the peninsula is controlled by the synoptic wind. An average convergence over the peninsula happens from 14:00 to 22:30 UTC, with a maximum at 18:00 UTC. There is a strong potential temperature gradient between the surface of the peninsula and the sea, with the sea breeze circulation system extending up to 1.2 km or higher. The sensible heat flux reaches 80 W/m2at the top of mountains and 10 W/m2near the coast.

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