scholarly journals A 250‐Year, Decadally Resolved, Radiocarbon Time History in the Gulf of Maine Reveals a Hydrographic Regime Shift at the End of the Little Ice Age

2020 ◽  
Vol 125 (9) ◽  
Author(s):  
Erin E. Lower‐Spies ◽  
Nina M. Whitney ◽  
Alan D. Wanamaker ◽  
Shelly M. Griffin ◽  
Douglas S. Introne ◽  
...  
Keyword(s):  
Little Ice Age ◽  
Regime Shift ◽  
Gulf Of Maine ◽  
Time History ◽  
Ice Age

Indications for a North Atlantic ocean circulation regime shift at the onset of the Little Ice Age

2015 ◽  
Vol 45 (11-12) ◽  
pp. 3623-3633 ◽  
Author(s):  
C.-F. Schleussner ◽  
D. V. Divine ◽  
J. F. Donges ◽  
A. Miettinen ◽  
R. V. Donner
Keyword(s):  
Atlantic Ocean ◽  
Ocean Circulation ◽  
North Atlantic ◽  
Little Ice Age ◽  
Regime Shift ◽  
North Atlantic Ocean ◽  
Ice Age ◽  
Circulation Regime

Recent woody invasion of wetlands on the Kenai Peninsula Lowlands, south-central Alaska: a major regime shift after 18 000 years of wet Sphagnum–sedge peat recruitment

2009 ◽  
Vol 39 (11) ◽  
pp. 2033-2046 ◽  
Author(s):  
Edward E. Berg ◽  
Kacy McDonnell Hillman ◽  
Roman Dial ◽  
Allana DeRuwe
Keyword(s):  
Little Ice Age ◽  
Regime Shift ◽  
Black Spruce ◽  
Ice Age ◽  
Woody Vegetation ◽  
Kenai Peninsula ◽  
South Central ◽  
Historical Aerial Photography ◽  
Dwarf Birch ◽  
Summer Temperatures

We document accelerating invasion of woody vegetation into wetlands on the western Kenai Peninsula lowlands. Historical aerial photography for 11 wetland sites showed that herbaceous area shrank 6.2%/decade from 1951 to 1968, and 11.1%/decade from 1968 to 1996. Corresponding rates for converting herbaceous area to shrubland were 11.5% and 13.7%/decade, respectively, and, for converting nonforest to forest, were 7.8% and 8.3%/decade, respectively. Black spruce ( Picea mariana (Mill.) BSP) forests on three wetland perimeters established since the Little Ice Age concluded in the 1850s. Dwarf birch shrubs at three wetland sites showed median apparent tree-ring age of 13 years, indicating recent shrub colonization at these sites. Peat cores at 24 wetland sites (basal peat ages 1840 – 18 740 calibrated years before present) indicated that these peatlands originated as wet Sphagnum –sedge fens with very little woody vegetation. Local meteorological records show a 55% decline in available water since 1968, of which one-third is due to higher summer temperatures and increased evapotranspiration and two-thirds is due to lower annual precipitation. These results suggest that wet Sphagnum–sedge fens initiating since the end of the Wisconsin glaciation began to dry in the 1850s and that this drying has greatly accelerated since the 1970s.

scholarly journals A volcanically triggered regime shift in the subpolar North Atlantic Ocean as a possible origin of the Little Ice Age

2013 ◽  
Vol 9 (3) ◽  
pp. 1321-1330 ◽  
Author(s):  
C. F. Schleussner ◽  
G. Feulner
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Little Ice Age ◽  
Regime Shift ◽  
Regional Climate ◽  
Volcanic Eruptions ◽  
Meridional Overturning Circulation ◽  
Ice Age ◽  
Last Millennium ◽  
Subpolar Gyre

Abstract. Among the climatological events of the last millennium, the Northern Hemisphere Medieval Climate Anomaly succeeded by the Little Ice Age are of exceptional importance. The origin of these regional climate anomalies remains a subject of debate and besides external influences like solar and volcanic activity, internal dynamics of the climate system might have also played a dominant role. Here, we present transient last millennium simulations of the fully coupled model of intermediate complexity Climber 3α forced with stochastically reconstructed wind-stress fields. Our results indicate that short-lived volcanic eruptions might have triggered a cascade of sea ice–ocean feedbacks in the North Atlantic, ultimately leading to a persistent regime shift in the ocean circulation. We find that an increase in the Nordic Sea sea-ice extent on decadal timescales as a consequence of major volcanic eruptions in our model leads to a spin-up of the subpolar gyre and a weakened Atlantic meridional overturning circulation, eventually causing a persistent, basin-wide cooling. These results highlight the importance of regional climate feedbacks such as a regime shift in the subpolar gyre circulation for understanding the dynamics of past and future climate.

scholarly journals A volcanically triggered regime shift in the subpolar North Atlantic ocean as a possible origin of the Little Ice Age

2012 ◽  
Vol 8 (6) ◽  
pp. 6199-6219 ◽  
Author(s):  
C. F. Schleussner ◽  
G. Feulner
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Little Ice Age ◽  
Regime Shift ◽  
Regional Climate ◽  
Volcanic Eruptions ◽  
Meridional Overturning Circulation ◽  
Ice Age ◽  
Last Millennium ◽  
Subpolar Gyre

Abstract. Among the climatological events of the last millennium, the Northern Hemisphere Medieval Climate Anomaly (MCA), succeeded by the Little Ice Age (LIA) are of exceptional importance. The origin of these regional climate anomalies remains however a subject of debate and besides external influences like solar and volcanic activity, internal dynamics of the climate system might have also played a dominant role. Here, we present transient last millennium simulations of the fully-coupled model Climber 3α forced with stochastically reconstructed wind fields. Our results indicate that short-lived volcanic eruptions might have triggered a cascade of sea-ice – ocean feedbacks in the North Atlantic, ultimately leading to a persistent regime shift in the ocean circulation. We find that an increase in the Nordic Sea sea-ice extent on decadal timescales as a consequence of major volcanic eruptions leads to a spin-up of the subpolar gyre (SPG) and a weakened Atlantic Meridional Overturning Circulation, eventually causing a persistent, basin-wide cooling. These results highlight the importance of regional climate feedbacks such as a regime shift in the subpolar gyre circulation for past and future climate.

Greenhouses, hot water bottles, cycles and the future of New Zealand climate

2009 ◽  
pp. 61-67
Author(s):  
W.P. De Lange
Keyword(s):  
New Zealand ◽  
Thermal Energy ◽  
Infrared Radiation ◽  
Little Ice Age ◽  
Hot Water ◽  
Ice Age ◽  
The Sun ◽  
Weather Patterns ◽  
Time Periods ◽  
Almost All

The Greenhouse Effect acts to slow the escape of infrared radiation to space, and hence warms the atmosphere. The oceans derive almost all of their thermal energy from the sun, and none from infrared radiation in the atmosphere. The thermal energy stored by the oceans is transported globally and released after a range of different time periods. The release of thermal energy from the oceans modifies the behaviour of atmospheric circulation, and hence varies climate. Based on ocean behaviour, New Zealand can expect weather patterns similar to those from 1890-1922 and another Little Ice Age may develop this century.

RECOVERY FROM THE LITTLE ICE AGE: GEOTHERMAL EVIDENCES

2013 ◽  
Vol 6 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Anastasia Gornostayeva ◽  
◽  
Dmitry Demezhko ◽  
◽  
Keyword(s):  
Little Ice Age ◽  
Ice Age

LITTLE ICE AGE IN THE EARTH HISTORY AND ITS POSSIBLE REASONS

2020 ◽  
Vol 42 (1) ◽  
pp. 4-12
Author(s):  
Valeriy Fedorov ◽  
Denis Frolov
Keyword(s):  
Little Ice Age ◽  
Ice Age ◽  
Earth History ◽  
The Earth
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