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1. Introduction The North Atlantic Oscillation (NAO) is considered to be the main pattern of the variability of atmospheric circulation in the North Atlantic area. The effects of the NAO on precipitation and temperature have been analyzed in several publications (e.g., Hurrell 1995 ; Ulbrich et al. 1999 ), but studies on the relationship between the NAO and lightning are limited, perhaps because during the winter, when the NAO is stronger, lightning is at a minimum at middle and high
1. Introduction The North Atlantic Oscillation (NAO) is considered to be the main pattern of the variability of atmospheric circulation in the North Atlantic area. The effects of the NAO on precipitation and temperature have been analyzed in several publications (e.g., Hurrell 1995 ; Ulbrich et al. 1999 ), but studies on the relationship between the NAO and lightning are limited, perhaps because during the winter, when the NAO is stronger, lightning is at a minimum at middle and high
1. Introduction The atmospheric flow of the Northern Hemisphere in winter exhibits considerable variability on intraseasonal, interannual, and decadal time scales. The North Atlantic Oscillation (NAO) is the most prominent low-frequency dipole mode of atmospheric variability in the mid- to high latitudes of the Northern Hemisphere ( Walker and Bliss 1932 ; Feldstein 2000 ; Woollings et al. 2008 ), which has been recognized to have a profound effect not only on regional weather and climate but
1. Introduction The atmospheric flow of the Northern Hemisphere in winter exhibits considerable variability on intraseasonal, interannual, and decadal time scales. The North Atlantic Oscillation (NAO) is the most prominent low-frequency dipole mode of atmospheric variability in the mid- to high latitudes of the Northern Hemisphere ( Walker and Bliss 1932 ; Feldstein 2000 ; Woollings et al. 2008 ), which has been recognized to have a profound effect not only on regional weather and climate but
1. Introduction Teleconnections—long-range, spatially coherent, and time-varying regions of correlation or anticorrelation in the sea level pressure and other atmospheric fields—are extremely important manifestations of low-frequency climate variability ( Wallace and Gutzler 1981 , hereafter WG ; Hurrell 1996 ). The North Atlantic Oscillation (NAO), a meridional “seesaw” or dipole in atmospheric pressure with centers of action near the Azores and Iceland, is among the most significant of
1. Introduction Teleconnections—long-range, spatially coherent, and time-varying regions of correlation or anticorrelation in the sea level pressure and other atmospheric fields—are extremely important manifestations of low-frequency climate variability ( Wallace and Gutzler 1981 , hereafter WG ; Hurrell 1996 ). The North Atlantic Oscillation (NAO), a meridional “seesaw” or dipole in atmospheric pressure with centers of action near the Azores and Iceland, is among the most significant of
of summer (i.e., early and late summers as divided in the study), which will be shown in section 3 . Then section 4 will illustrate the relationship between the North Atlantic Oscillation and the SRP in early and late summers, respectively. Finally in section 5 , the conclusions and a discussion will be given. The remnant of this paper will start with an introduction for the dataset and method, as in section 2 . 2. Dataset and method The data used in this study include the daily and monthly
of summer (i.e., early and late summers as divided in the study), which will be shown in section 3 . Then section 4 will illustrate the relationship between the North Atlantic Oscillation and the SRP in early and late summers, respectively. Finally in section 5 , the conclusions and a discussion will be given. The remnant of this paper will start with an introduction for the dataset and method, as in section 2 . 2. Dataset and method The data used in this study include the daily and monthly
1. Introduction Empirical orthogonal function (EOF) analysis is widely used in the climate community to define large-scale climate patterns. EOF analysis provides the eigenvectors and eigenvalues of the spatial covariance matrix of a meteorological field, thereby characterizing the spatial patterns of atmospheric and oceanic variability, which organize coherent variations over large regions (for a review see, e.g., Hannachi et al. 2007 ). For instance, the wintertime North Atlantic Oscillation
1. Introduction Empirical orthogonal function (EOF) analysis is widely used in the climate community to define large-scale climate patterns. EOF analysis provides the eigenvectors and eigenvalues of the spatial covariance matrix of a meteorological field, thereby characterizing the spatial patterns of atmospheric and oceanic variability, which organize coherent variations over large regions (for a review see, e.g., Hannachi et al. 2007 ). For instance, the wintertime North Atlantic Oscillation
to several causes, including the propagation of atmospheric Kelvin and Rossby waves, changes in thermally direct circulations, intrinsic modes of atmospheric variability, and changes in the oceans’ wind-driven or thermohaline circulation. The terms “teleconnection” and “oscillation” have often been used synonymously in meteorology, ever since the discovery of the North Atlantic, North Pacific, and Southern Oscillations by G. Walker and associates (e.g., Walker and Bliss 1932 , 1937 ); in these
to several causes, including the propagation of atmospheric Kelvin and Rossby waves, changes in thermally direct circulations, intrinsic modes of atmospheric variability, and changes in the oceans’ wind-driven or thermohaline circulation. The terms “teleconnection” and “oscillation” have often been used synonymously in meteorology, ever since the discovery of the North Atlantic, North Pacific, and Southern Oscillations by G. Walker and associates (e.g., Walker and Bliss 1932 , 1937 ); in these
1. Introduction The North Atlantic Oscillation (NAO) is a dominant mode of atmospheric variability in the Northern Hemisphere (e.g., Wallace and Gutzler 1981 ; Barnston and Livezey 1987 ). The main characteristics of the NAO include a dipole spatial structure in sea level pressure over the North Atlantic, with one center over Greenland and the other center of opposite sign along the North Atlantic between 35° and 40°N, and an equivalent barotropic vertical structure. With a time scale ranging
1. Introduction The North Atlantic Oscillation (NAO) is a dominant mode of atmospheric variability in the Northern Hemisphere (e.g., Wallace and Gutzler 1981 ; Barnston and Livezey 1987 ). The main characteristics of the NAO include a dipole spatial structure in sea level pressure over the North Atlantic, with one center over Greenland and the other center of opposite sign along the North Atlantic between 35° and 40°N, and an equivalent barotropic vertical structure. With a time scale ranging
interannual estimate agrees with those previously derived by Schott and Zantopp for the same frequency band, using approximately 8 yr of sea level differences between Bimini and Miami. Suggestion has been made in the literature of a relationship between variations in FC transport and interannual and longer-period atmospheric signals. Baringer and Larsen (2001) compared a 2-yr running mean of FC cable transport with variations in the North Atlantic Oscillation (NAO) index over the period 1982
interannual estimate agrees with those previously derived by Schott and Zantopp for the same frequency band, using approximately 8 yr of sea level differences between Bimini and Miami. Suggestion has been made in the literature of a relationship between variations in FC transport and interannual and longer-period atmospheric signals. Baringer and Larsen (2001) compared a 2-yr running mean of FC cable transport with variations in the North Atlantic Oscillation (NAO) index over the period 1982
1. Introduction The North Atlantic Oscillation (NAO) is one of the most prominent and recurrent patterns of atmospheric circulation variability in the Northern Hemisphere. This phenomenon has attracted wide interest among scientists owing to its wide impact on weather and climate ( Hurrell 1995 ). For example, it has been revealed that the cool-season (November–April) northeastern U.S. precipitation tends to be enhanced during positive-to-negative NAO transitions ( Archambault et al. 2010
1. Introduction The North Atlantic Oscillation (NAO) is one of the most prominent and recurrent patterns of atmospheric circulation variability in the Northern Hemisphere. This phenomenon has attracted wide interest among scientists owing to its wide impact on weather and climate ( Hurrell 1995 ). For example, it has been revealed that the cool-season (November–April) northeastern U.S. precipitation tends to be enhanced during positive-to-negative NAO transitions ( Archambault et al. 2010
). December 2010 was the coldest December for over 40 yr in Germany and France, with monthly mean temperatures between 3° and 5°C below normal, while Norway had its fourth coldest December on record. Societal impacts were large: for instance, airports were closed due to snow in France, Belgium, Switzerland, Germany, and the Netherlands ( Blunden et al. 2011 ). Surrounding the North Atlantic basin, the quadrupole pattern typical of a negative phase of the North Atlantic Oscillation (NAO) was observed
). December 2010 was the coldest December for over 40 yr in Germany and France, with monthly mean temperatures between 3° and 5°C below normal, while Norway had its fourth coldest December on record. Societal impacts were large: for instance, airports were closed due to snow in France, Belgium, Switzerland, Germany, and the Netherlands ( Blunden et al. 2011 ). Surrounding the North Atlantic basin, the quadrupole pattern typical of a negative phase of the North Atlantic Oscillation (NAO) was observed
