КЛИМАТИЧЕСКАЯ ИЗМЕНЧИВОСТЬ ИНДЕКСА СЕВЕРО-АТЛАНТИЧЕСКОГО КОЛЕБАНИЯ (САК) И СВЯЗАННЫЕ С НЕЙ ФЛУКТУАЦИИ ТЕМПЕРАТУРЫ

Processes of formation of the North Atlantic Oscillation index (NAO) during different phases of the current (1868–2010) quasi-centurial variability of solar activity (the Wolf number) are considered. It is found that during the lowest solar activity of a quasi-centurial cycle, the NAO index tends to the value higher than those observed during maximum of solar activity. During the even cycles the NAO index tends to be a few times higher than those during the odd ones. The conceptual scheme is proposed assuming that at anomalously high NAO taking place mainly during even cycles, the western disturbance in the troposphere over the North Atlantic groves that intensifi es circulation in the upper layer of the subtropical gyre, leading to decrease of the amount of the Atlantic water mass infl owing to high latitudes. At anomalously low NAO observed mainly during the odd cycles, circulation in the subtropical gyre weakens that results in increase of the amount of the Atlantic water mass infl owing to high latitudes through the Faeroe–Shetland channel to the Norwegian and Barents seas. The range of the NAO variability is found (±0.5), at which average multi-year (climatic) regime of hydrometeorological characteristics is realized in the North Atlantic. Validity of the proposed conceptual scheme is confi rmed by the materials on water mass transport through the Faeroe–Shetland channel, formation of temperature anomalies in the North Atlantic upper layer and the Barents sea ice cover at NAO = ±0.5; NAO ≥ 1 and NAO ≤ –1.