scholarly journals Sea ice predicts long‐term trends in Adélie penguin population growth, but not annual fluctuations: Results from a range‐wide multiscale analysis

2020 ◽  
Vol 26 (7) ◽  
pp. 3788-3798 ◽  
Author(s):  
David T. Iles ◽  
Heather Lynch ◽  
Rubao Ji ◽  
Christophe Barbraud ◽  
Karine Delord ◽  
...  
Keyword(s):  
Sea Ice ◽  
Population Growth ◽  
Multiscale Analysis ◽  
Adélie Penguin ◽  
Adelie Penguin ◽  
Long Term Trends

A 1000-year record of Adélie penguin diets in the southern Ross Sea

2002 ◽  
Vol 14 (4) ◽  
pp. 327-332 ◽  
Author(s):  
MICHAEL POLITO ◽  
STEVEN D. EMSLIE ◽  
WILLIAM WALKER
Keyword(s):  
Ross Sea ◽  
Prey Selection ◽  
Ice Age ◽  
Adélie Penguin ◽  
Pleuragramma Antarcticum ◽  
Adelie Penguin ◽  
Radiocarbon Dates ◽  
Antarctic Silverfish ◽  
The Antarctic

Non-krill prey remains were recovered from ornithogenic sediments at three active Adélie penguin colonies on Ross Island, to assess long-term dietary trends in this species. Radiocarbon dates place the age of these deposits from a maximum of 947 years ago to the present. We identified 12 taxa of fish and two of squid with the Antarctic silverfish (Pleuragramma antarcticum) as the most abundant prey species represented at all sites. In addition, silverfish have decreased in importance in Adélie penguin diet over the past 600 years, perhaps in response to climate change since the onset of the Little Ice Age, though it remains much more abundant in current penguin diet in the Ross Sea than in the Antarctic Peninsula. Other prey taxa reflect the diversity of prey selection by Adélie penguins in Antarctica.

Impact of Winds and Southern Ocean SSTs on Antarctic Sea Ice Trends and Variability

2021 ◽  
Vol 34 (3) ◽  
pp. 949-965
Author(s):  
Edward Blanchard-Wrigglesworth ◽  
Lettie A. Roach ◽  
Aaron Donohoe ◽  
Qinghua Ding
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Interannual Variability ◽  
Initial Conditions ◽  
Regional Scale ◽  
Earth System ◽  
Anthropogenic Forcing ◽  
Antarctic Sea Ice ◽  
Long Term Trends

AbstractAntarctic sea ice extent (SIE) has slightly increased over the satellite observational period (1979 to the present) despite global warming. Several mechanisms have been invoked to explain this trend, such as changes in winds, precipitation, or ocean stratification, yet there is no widespread consensus. Additionally, fully coupled Earth system models run under historic and anthropogenic forcing generally fail to simulate positive SIE trends over this time period. In this work, we quantify the role of winds and Southern Ocean SSTs on sea ice trends and variability with an Earth system model run under historic and anthropogenic forcing that nudges winds over the polar regions and Southern Ocean SSTs north of the sea ice to observations from 1979 to 2018. Simulations with nudged winds alone capture the observed interannual variability in SIE and the observed long-term trends from the early 1990s onward, yet for the longer 1979–2018 period they simulate a negative SIE trend, in part due to faster-than-observed warming at the global and hemispheric scale in the model. Simulations with both nudged winds and SSTs show no significant SIE trends over 1979–2018, in agreement with observations. At the regional scale, simulated sea ice shows higher skill compared to the pan-Antarctic scale both in capturing trends and interannual variability in all nudged simulations. We additionally find negligible impact of the initial conditions in 1979 on long-term trends.

scholarly journals Antarctic and Southern Ocean Sea-Ice and Climate Trends

1990 ◽  
Vol 14 ◽  
pp. 127-130 ◽  
Author(s):  
T.H Jacka
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Data Sets ◽  
Climate Trends ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
South Pacific Ocean ◽  
Computer Based ◽  
Long Term Trends

A computer-based climate monitoring project is described. Data sets include monthly and annual mean surface temperatures and pressures for occupied stations in Antarctica, the Southern Ocean and South Pacific Ocean; and monthly Antarctic sea-ice extent at each 10° of longitude.Simple statistical analyses of the data sets reveal a mean warming of ~0.15°C (10 a)−1 since the mid 1950s for Antarctic coastal stations and of ~0.04°C (10 a)−1 since the mid 1940s for the ocean stations. The sea-ice record from 1973 to 1988 reveals that the average northern ice limit has decreased at ~0.23°lat. (10 a)−1. Despite apparently compatible long-term trends of temperature and sea-ice extent, annual fluctuations of temperature and ice extent are highly variable and are not well correlated.

Growth and Trade: Some Hypotheses About Long-Term Trends

1964 ◽  
Vol 24 (4) ◽  
pp. 609-628 ◽  
Author(s):  
Richard N. Cooper
Keyword(s):  
Population Growth ◽  
Foreign Trade ◽  
The World ◽  
Long Term Trends ◽  
The Relationship

The relationship between long-term trends in foreign trade and long-term trends in income has long been a source of fascinating speculation for scholars. As early as 1821, Robert Torrens observed that “as the several nations of the world advance in wealth and population, the commercial intercourse between them must gradually become less important and beneficial.” He believed that trade was founded on the exchange of manufactures for foodstuffs and materials; as land became scarcer as a result of population growth, the basis for trade would disappear.

scholarly journals Antarctic and Southern Ocean Sea-Ice and Climate Trends

1990 ◽  
Vol 14 ◽  
pp. 127-130 ◽  
Author(s):  
T.H Jacka
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Data Sets ◽  
Climate Trends ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
South Pacific Ocean ◽  
Computer Based ◽  
Long Term Trends

A computer-based climate monitoring project is described. Data sets include monthly and annual mean surface temperatures and pressures for occupied stations in Antarctica, the Southern Ocean and South Pacific Ocean; and monthly Antarctic sea-ice extent at each 10° of longitude. Simple statistical analyses of the data sets reveal a mean warming of ~0.15°C (10 a)−1 since the mid 1950s for Antarctic coastal stations and of ~0.04°C (10 a)−1 since the mid 1940s for the ocean stations. The sea-ice record from 1973 to 1988 reveals that the average northern ice limit has decreased at ~0.23°lat. (10 a)−1. Despite apparently compatible long-term trends of temperature and sea-ice extent, annual fluctuations of temperature and ice extent are highly variable and are not well correlated.

Comparison of emperor penguin declines between Pointe Géologie and Haswell Island over the past 50 years

2011 ◽  
Vol 23 (5) ◽  
pp. 461-468 ◽  
Author(s):  
Christophe Barbraud ◽  
Maria Gavrilo ◽  
Yuri Mizin ◽  
Henri Weimerskirch
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Future Climate Change ◽  
Emperor Penguin ◽  
Sea Ice Extent ◽  
Island Populations ◽  
Dramatic Decline ◽  
Ice Conditions ◽  
Long Term Trends

AbstractThe emperor penguin (Aptenodytes forsteri) is highly dependent on sea ice conditions, and future climate change may affect its distribution and numbers. Most studies on the demography and population dynamics of emperor penguins in relation to sea ice characteristics were conducted at a single colony (Pointe Géologie). Several non-exclusive hypotheses have been proposed to explain the dramatic decline of this colony, including changes in sea ice conditions, predation, flipper banding and human disturbance. Here, we report and analyse updated long-term trends in numbers of breeding pairs made at two colonies (Pointe Géologie and Haswell Island) where counts are comparable. Similar changes were observed for both colonies and paralleled changes in sea ice extent. At Pointe Géologie and Haswell Island, populations declined similarly and later growth rates were also similar since the early 1990s for Haswell and early 1980s for Pointe Géologie. The magnitude of the decline was similar between both colonies when numbers of breeding pairs were assessed. This study suggests that a common large-scale environmental factor has probably negatively affected both colonies.

SEA ICE COVER AND ITS INFLUENCE ON ADÉLIE PENGUIN REPRODUCTIVE PERFORMANCE

Ecology ◽  
2008 ◽  
Vol 89 (8) ◽  
pp. 2096-2102 ◽  
Author(s):  
Louise Emmerson ◽  
Colin Southwell
Keyword(s):  
Sea Ice ◽  
Reproductive Performance ◽  
Ice Cover ◽  
Adélie Penguin ◽  
Adelie Penguin
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