scholarly journals Multiscale Variability in North American Summer Maximum Temperatures and Modulations from the North Atlantic Simulated by an AGCM

2018 ◽  
Vol 31 (7) ◽  
pp. 2549-2562 ◽  
Author(s):  
Nicolas Vigaud ◽  
M. Ting ◽  
D.-E. Lee ◽  
A. G. Barnston ◽  
Y. Kushnir
Keyword(s):  
United States ◽  
North America ◽  
North Atlantic ◽  
Seasonal Cycle ◽  
The United States ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Northeastern United States ◽  
The North ◽  
The North Atlantic

Six recurrent thermal regimes are identified over continental North America from June to September through a k-means clustering applied to daily maximum temperature simulated by ECHAM5 forced by historical SSTs for 1930–2013 and validated using NCEP–DOE AMIP-II reanalysis over the 1980–2009 period. Four regimes are related to a synoptic wave pattern propagating eastward in the midlatitudes with embedded ridging anomalies that translate into maximum warming transiting along. Two other regimes, associated with broad continental warming and above average temperatures in the northeastern United States, respectively, are characterized by ridging anomalies over North America, Europe, and Asia that suggest correlated heat wave occurrences in these regions. Their frequencies are mainly related to both La Niña and warm conditions in the North Atlantic. Removing all variability beyond the seasonal cycle in the North Atlantic in ECHAM5 leads to a significant drop in the occurrences of the regime associated with warming in the northeastern United States. Superimposing positive (negative) anomalies mimicking the Atlantic multidecadal variability (AMV) in the North Atlantic translates into more (less) warming over the United States across all regimes, and does alter regime frequencies but less significantly. Regime frequency changes are thus primarily controlled by Atlantic SST variability on all time scales beyond the seasonal cycle, rather than mean SST changes, whereas the intensity of temperature anomalies is impacted by AMV SST forcing, because of upper-tropospheric warming and enhanced stability suppressing rising motion during the positive phase of the AMV.

scholarly journals Impacts of the North Atlantic Oscillation on Winter Precipitations and Storm Track Variability in Southeast Canada and Northeast US

2020 ◽  
Author(s):  
Julien Chartrand ◽  
Francesco Salvatore Rocco Pausata
Keyword(s):  
United States ◽  
North America ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Storm Track ◽  
The United States ◽  
Eastern North America ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

Abstract. The North Atlantic Oscillation (NAO) affects atmospheric variability from eastern North America to Europe. Although the link between the NAO and winter precipitations in the eastern North America have been the focus of previous work, only few studies have hitherto provided clear physical explanations on these relationships. In this study we revisit and extend the analysis of the effect of the NAO on winter precipitations over a large domain covering southeast Canada and the northeastern United States. Furthermore, here we use the recent ERA5 reanalysis dataset (1979–2018), which currently has the highest available horizontal resolution for a global reanalysis (0.25°), to track extratropical cyclones to delve into the physical processes behind the relationship between NAO and precipitation, snowfall, snowfall-to-precipitation ratio (S/P), and snow cover depth anomalies in the region. In particular, our results show that positive NAO phases are associated with less snowfall over a wide region covering Nova Scotia, New England and the Mid-Atlantic of the United States relative to negative NAO phases. Henceforth, a significant negative correlation is also seen between S/P and the NAO over this region. This is due to a decrease (increase) in cyclogenesis of coastal storms near the United States east coast during positive (negative) NAO phases, as well as a northward (southward) displacement of the mean storm track over North America.

scholarly journals Impacts of the North Atlantic Oscillation on winter precipitations and storm track variability in southeast Canada and the northeast United States

2020 ◽  
Vol 1 (2) ◽  
pp. 731-744
Author(s):  
Julien Chartrand ◽  
Francesco S. R. Pausata
Keyword(s):  
United States ◽  
North America ◽  
North Atlantic ◽  
Storm Track ◽  
The United States ◽  
Eastern North America ◽  
Heavy Snowfall ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

Abstract. The North Atlantic Oscillation (NAO) affects atmospheric variability from eastern North America to Europe. Although the link between the NAO and winter precipitations in eastern North America has been the focus of previous work, only few studies have considered extreme precipitation and hitherto provided clear physical explanations on these relationships. In this study we revisit and extend the analysis of the effect of the NAO on mean and heavy winter precipitations over a large domain covering southeast Canada and the northeastern United States. Furthermore, we use the recent ERA5 reanalysis dataset (1979–2018), which currently has the highest available horizontal resolution for a global reanalysis (0.25∘), to track extratropical cyclones to delve into the physical processes behind the relationship between NAO and precipitation, snowfall, snowfall-to-precipitation ratio (S∕P), and snow cover depth anomalies in the region. In particular, our results show that positive NAO phases are associated with less snowfall over a wide region covering Nova Scotia, New England and the Mid-Atlantic of the United States relative to negative NAO phases. Over the same area, the analysis of heavy snowfall revealed that there are up to twice as many heavy snowfall events during negative phases compared to positive phases. Therefore, a significant negative correlation is also seen between S∕P and the NAO over this region. This is due to a decrease (increase) in cyclogenesis of coastal storms near the United States east coast during positive (negative) NAO phases, as well as a northward (southward) displacement of the mean storm track over North America.

Allied High Commission for Germany

1951 ◽  
Vol 5 (4) ◽  
pp. 825-832
Keyword(s):  
United States ◽  
North Atlantic ◽  
Foreign Minister ◽  
The United States ◽  
Scrap Metal ◽  
German Federal Republic ◽  
The North ◽  
The United Kingdom ◽  
The North Atlantic ◽  
Contractual Agreements

With the development of certain administrative frictions (concerning coal quotas, occupation costs, and the scrap metal treaty) between the western occupying powers and the German Federal Republic, early indications were that if the talk of “contractual agreements” did materialize it would reserve, for the occupying powers, wide controls over important areas of west Germany's internal and external affairs. In Washington, however, a general modification of approach was noted during the September discussions between the United States Secretary of State (Acheson), the United Kingdom Foreign Secretary (Morrison), and the French Foreign Minister (Schuman), preparatory to the Ottawa meetings of the North Atlantic Council.

Strategy and the Atlantic Alliance

1963 ◽  
Vol 17 (3) ◽  
pp. 709-732 ◽  
Author(s):  
Robert R. Bowie
Keyword(s):  
United States ◽  
North Atlantic ◽  
North Atlantic Treaty Organization ◽  
The United States ◽  
The North ◽  
Nuclear Control ◽  
The North Atlantic ◽  
The Military

The debate over strategy, forces, and nuclear control, which now divides the North Atlantic Treaty Organization (NATO), is framed largely in military terms: what is the best way to protect the NATO area and its members from aggression? The military aspects are complex in themselves, but the import of these issues extends far beyond defense. Their handling will greatly affect prospects for a partnership between the United States and a strong, united Europe

Shaping the postwar balance of power: multilateralism in NATO

1992 ◽  
Vol 46 (3) ◽  
pp. 633-680 ◽  
Author(s):  
Steve Weber
Keyword(s):  
United States ◽  
Soviet Union ◽  
North Atlantic ◽  
Balance Of Power ◽  
The United States ◽  
The North ◽  
The Soviet Union ◽  
The North Atlantic ◽  
Multilateral Organization ◽  
John Ruggie

At the end of the 1940s, the United States and several West European states allied to defend themselves against invasion by the Soviet Union. Balance-ofpower theory predicts the recurrent formation of such balances among states. But it says little about the precise nature of the balance, the principles on which it will be constructed, or its institutional manifestations. The North Atlantic Treaty Organization (NATO) has been a peculiar mix. As a formal institution, NATO has through most of its history been distinctly nonmultilateral, with the United States commanding most decision-making power and responsibility. At the same time, NATO provided security to its member states in a way that strongly reflected multilateral principles. Within NATO, security was indivisible. It was based on a general organizing principle, the principle that the external boundaries of alliance territory were completely inviolable and that an attack on any border was an attack on all. Diffuse reciprocity was the norm. In the terms set out by John Ruggie, NATO has generally scored low as a multilateral organization but high as an institution of multilateralism.

The Shipping of the North Atlantic Cotton Trade in the Mid-Nineteenth Century

2000 ◽  
Author(s):  
Lars U. Scholl ◽  
Lars U. Scholl ◽  
Lars U. Scholl
Keyword(s):  
United States ◽  
North Atlantic ◽  
The United States ◽  
Southern States ◽  
Atlantic Trade ◽  
The North ◽  
Seasonal Characteristics ◽  
Arrival Dates ◽  
The North Atlantic ◽  
Cotton Trade

This essay analyses the North Atlantic Cotton Trade through records of cotton arrivals at Liverpool, using two sets of data from 1830-1832 and 1853-1855. Using Customs Bills of Entry, Williams presents data of cotton receipts from the United States to Liverpool; quantities of bales exported; numbers of vessels; origin ports of vessels; distinguishes between regular and occasional cotton traders; arrivals at Liverpool by nationality; and vessel tonnage. He determines that the majority of vessels participated in the cotton trade seasonally, and suggests that the cotton trade was not self-contained, but part of a complex interrelationship within the North Atlantic trade system, encompassing commodity dealings, shipping employment levels, and the seasonal characteristics of cargo. The conclusion requests further scholarly research into the pattern of ship movements in the Atlantic. Two appendices provide more data, concerning arrival dates of regular traders in Liverpool, and the month of departure of cotton vessels from Southern states.

Decolonial Theology in the North Atlantic World

2019 ◽  
Vol 3 (3) ◽  
pp. 1-88
Author(s):  
Joseph Drexler-Dreis
Keyword(s):  
United States ◽  
North Atlantic ◽  
Social Transformation ◽  
Atlantic World ◽  
Ways Of Knowing ◽  
The United States ◽  
The North ◽  
The North Atlantic ◽  
Relations Of Power ◽  
General Perspective

Abstract This essay develops a response to the historical situation of the North Atlantic world in general and the United States in particular through theological reflection. It offers an overview of some decolonial perspectives with which theologians can engage, and argues for a general perspective for a decolonial theology as a possible response to modern/colonial structures and relations of power, particularly in the United States. Decolonial theory holds together a set of critical perspectives that seek the end of the modern/colonial world-system and not merely a democratization of its benefits. A decolonial theology, it is argued, critiques how the confinement of knowledge to European traditions has closed possibilities for understanding historical encounters with divinity, and thus possibilities of critical reflection. A decolonial theology reflects critically on a historical situation in light of faith in a divine reality, the understanding of which is liberated from the monopoly of modern/colonial ways of knowing, in order to catalyze social transformation.

scholarly journals Hurricane Katrina (2005). Part II: Evolution and Hemispheric Impacts of a Diabatically Generated Warm Pool

2007 ◽  
Vol 135 (12) ◽  
pp. 3927-3949 ◽  
Author(s):  
Ron McTaggart-Cowan ◽  
Lance F. Bosart ◽  
John R. Gyakum ◽  
Eyad H. Atallah
Keyword(s):  
United States ◽  
Hurricane Katrina ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Flow Analysis ◽  
Warm Pool ◽  
The United States ◽  
The North ◽  
The North Atlantic ◽  
Upper Level

Abstract The landfall of Hurricane Katrina (2005) near New Orleans, Louisiana, on 29 August 2005 will be remembered as one of the worst natural disasters in the history of the United States. By comparison, the extratropical transition (ET) of the system as it accelerates poleward over the following days is innocuous and the system weakens until its eventual demise off the coast of Greenland. The extent of Katrina’s perturbation of the midlatitude flow would appear to be limited given the lack of reintensification or downstream development during ET. However, the slow progression of a strong upper-tropospheric warm pool across the North Atlantic Ocean in the week following Katrina’s landfall prompts the question of whether even a nonreintensifying ET event can lead to significant modification of the midlatitude flow. Analysis of Hurricane Katrina’s outflow layer after landfall suggests that it does not itself make up the long-lived midlatitude warm pool. However, the interaction between Katrina’s anticyclonic outflow and an approaching baroclinic trough is shown to establish an anomalous southwesterly conduit or “freeway” that injects a preexisting tropospheric warm pool over the southwestern United States into the midlatitudes. This warm pool reduces predictability in medium-range forecasts over the North Atlantic and Europe while simultaneously aiding in the development of Hurricanes Maria and Nate. The origin of the warm pool is shown to be the combination of anticyclonic upper-level features generated by eastern Pacific Hurricane Hilary and the south Asian anticyclone (SAA). The hemispheric nature of the connections involved with the development of the warm pool and its injection into the extratropics has an impact on forecasting, since the predictability issue associated with ET in this case involves far more than the potential reintensification of the transitioning system itself.

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