scholarly journals Twentieth century correlations between extratropical SST variability and ITCZ shifts

2017 ◽  
Vol 44 (17) ◽  
pp. 9039-9047 ◽  
Author(s):  
Brian Green ◽  
John Marshall ◽  
Aaron Donohoe
Keyword(s):  
Twentieth Century ◽  
Sst Variability

scholarly journals Influence of the North Atlantic SST Variability on the Atmospheric Circulation during the Twentieth Century

2015 ◽  
Vol 28 (4) ◽  
pp. 1396-1416 ◽  
Author(s):  
Guillaume Gastineau ◽  
Claude Frankignoul
Keyword(s):  
Twentieth Century ◽  
North Atlantic ◽  
Lower Troposphere ◽  
Atlantic Multidecadal Oscillation ◽  
Early Winter ◽  
Tropical Forcing ◽  
The North ◽  
Sst Variability ◽  
Sst Anomaly ◽  
The North Atlantic

Abstract The ocean–atmosphere coupling in the North Atlantic is investigated during the twentieth century using maximum covariance analysis of sea surface temperature (SST) and 500-hPa geopotential height analyses and performing regressions on dynamical diagnostics such as Eady growth rate, wave activity flux, and velocity potential. The North Atlantic Oscillation (NAO) generates the so-called SST anomaly tripole. A rather similar SST anomaly tripole, with the subpolar anomaly displaced to the east and a more contracted subtropical anomaly, which is referred to as the North Atlantic horseshoe pattern, in turn influences the atmosphere. In the fall and early winter, the response is NAO like and primarily results from subpolar forcing centered over the Labrador Sea and off Newfoundland. In summer, the largest atmospheric response to SST resembles the east Atlantic pattern and results from a combination of subpolar and tropical forcing. To emphasize the interannual to multidecadal variability, the same analysis is repeated after low-pass filtering. The SST influence is dominated by the Atlantic multidecadal oscillation (AMO), which also has a horseshoe shape, but with larger amplitude in the subpolar basin. A warm AMO phase leads to an atmospheric warming limited to the lower troposphere in summer, while it leads to a negative phase of the NAO in winter. The winter influence of the AMO is suggested to be primarily forced by the Atlantic SSTs in the northern subtropics. Such influence of the AMO is found in winter instead of early winter because the winter SST anomalies have a larger persistence, presumably because of SST reemergence.

Climatic Influences on Midwest Drought during the Twentieth Century

2008 ◽  
Vol 21 (3) ◽  
pp. 517-531 ◽  
Author(s):  
Warren B. White ◽  
Alexander Gershunov ◽  
Jeffrey Annis
Keyword(s):  
Twentieth Century ◽  
Rainfall Variability ◽  
Annual Rainfall ◽  
Canonical Correlations ◽  
Sst Variability ◽  
Eastern Equatorial Pacific ◽  
The Pacific ◽  
The 1950S ◽  
Interdecadal Oscillation ◽  
Normal Rainfall

Abstract The Dustbowl Era drought in the 1930s was the principal Midwest drought of the twentieth century, occurring primarily in late spring–summer [April–August (AMJJA)] when >70% of annual rainfall normally occurred. Another major Midwest drought occurred in the 1950s but primarily in fall–early winter [September–December (SOND)] when normal rainfall was ∼1/2 as much. Optimized canonical correlation analysis (CCA) is applied to forecast AMJJA and SOND Midwest rainfall variability in cross-validated fashion from antecedent DJF and JJA sea surface temperature (SST) variability in the surrounding oceans. These CCA models simulate (i.e., hindcast, not forecast) the Dustbowl Era drought of the 1930s and four of seven secondary AMJJA droughts (≥3-yr duration) during the twentieth century, and the principal Midwest drought of the 1950s and one of three secondary SOND droughts. Diagnosing the model canonical correlations finds the superposition of tropical Pacific cool phases of the quasi-decadal oscillation (QDO) and interdecadal oscillation (IDO) responsible for secondary droughts in AMJJA when ENSO was weak and finds the eastern equatorial Pacific cool phase of the ENSO responsible for secondary droughts during SOND when ENSO was strong. These explain why secondary droughts in AMJJA occurred more often (nearly every decade) and were of longer duration than secondary droughts in SOND when decadal drought tendencies were usually interrupted by ENSO. These diagnostics also find the AMJJA Dustbowl Era drought in the 1930s and the principal SOND drought in the 1950s driven primarily by different phases (i.e., in quadrature) of the pentadecadal signal in the Pacific decadal oscillation (PDO).

scholarly journals Forced and Internal Twentieth-Century SST Trends in the North Atlantic*

2009 ◽  
Vol 22 (6) ◽  
pp. 1469-1481 ◽  
Author(s):  
Mingfang Ting ◽  
Yochanan Kushnir ◽  
Richard Seager ◽  
Cuihua Li
Keyword(s):  
Climate Change ◽  
Twentieth Century ◽  
North Atlantic ◽  
Function Analysis ◽  
Greenland Ice Sheet ◽  
Internal Variability ◽  
Climate Projections ◽  
Intergovernmental Panel ◽  
Sst Variability

Abstract In recent years, two alarming trends in North Atlantic climate have been noted: an increase in the intensity and frequency of Atlantic hurricanes and a rapid decrease in Greenland ice sheet volume. Both of these phenomena occurred while a significant warming took place in North Atlantic sea surface temperatures (SSTs), thus sparking a debate on whether the warming is a consequence of natural climate variations, anthropogenic forcing, or both; and if both, what their relative roles are. Here models and observations are used to detect and attribute long-term (multidecadal) twentieth-century North Atlantic (NA) SST changes to their anthropogenic and natural causes. A suite of Intergovernmental Panel on Climate Change (IPCC) twentieth-century (C20C) coupled model simulations with multiple ensemble members and a signal-to-noise maximizing empirical orthogonal function analysis are used to identify a model-based estimate of the forced, anthropogenic component in NA SST variability. Comparing the results to observations, it is argued that the long-term, observed, North Atlantic basin-averaged SSTs combine a forced global warming trend with a distinct, local multidecadal “oscillation” that is outside of the range of the model-simulated, forced component and most likely arose from internal variability. This internal variability produced a cold interval between 1900 and 1930, followed by 30 yr of relative warmth and another cold phase from 1960 to 1990, and a warming since then. This natural variation, referred to previously as the Atlantic Multidecadal Oscillation (AMO), thus played a significant role in the twentieth-century NA SST variability and should be considered in future, near-term climate projections as a mechanism that, depending on its behavior, can act either constructively or destructively with the region’s response to anthropogenic influence, temporarily amplifying or mitigating regional climate change.

Some Polish Composers of To-Day

Tempo ◽  
1948 ◽  
pp. 25-28
Author(s):  
Andrzej Panufnik
Keyword(s):  
Twentieth Century ◽  
Fertile Soil ◽  
Early Twentieth Century ◽  
Progressive Group ◽  
Karol Szymanowski

It is ten years since KAROL SZYMANOWSKI died at fifty-four. He was the most prominent representative of the “radical progressive” group of early twentieth century composers, which we call “Young Poland.” In their manysided and pioneering efforts they prepared the fertile soil on which Poland's present day's music thrives.

V1214: Edward Loughborough Keyes: An Early Twentieth Century Leader In Urology

2004 ◽  
Vol 171 (4S) ◽  
pp. 320-320
Author(s):  
Peter J. Stahl ◽  
E. Darracott Vaughan ◽  
Edward S. Belt ◽  
David A. Bloom ◽  
Ann Arbor
Keyword(s):  
Twentieth Century ◽  
Early Twentieth Century

Musical Journeys: Performing Migration in Twentieth-Century Music

2019 ◽  
Author(s):  
Florian Scheding
Keyword(s):  
Twentieth Century ◽  
Twentieth Century Music

Twentieth Century Classics

2009 ◽  
Author(s):  
Rajiva Wijesinha
Keyword(s):  
Twentieth Century

Twentieth-Century English

2006 ◽  
Author(s):  
Christian Mair
Keyword(s):  
Twentieth Century

Central Banking in the Twentieth Century

2009 ◽  
Author(s):  
John Singleton
Keyword(s):  
Twentieth Century ◽  
Central Banking
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