CHANGES IN METEOROLOGICAL CHARACTERISTICS OF THE NORTH ATLANTIC UNDER GLOBAL WARMING

Abstract

Trends in the ocean–atmosphere conditions of the North Atlantic under global warming, manifested since the second half of the 20th century and intensified in the early 21st century, are identified, and their relationship with storm activity is examined. Using data from the Climate Reanalyzer platform, the spatiotemporal variability of sea surface temperature, near-surface air temperature, the thermal contrast between the ocean and the atmosphere (defined as the difference between sea surface temperature and near-surface air temperature), mean sea level pressure, and wind fields at 250 hPa, which characterize the position and intensity of the jet stream, was analyzed.

Relative to the 1961–1990 climate baseline, sea surface temperature anomalies during 2021–2024 indicate widespread warming across the North Atlantic, with maximum values along the Gulf Stream and the North Atlantic Current. In contrast, anomalies relative to the 1991–2020 baseline are weaker and more spatially heterogeneous, with a persistent region of reduced warming in the subpolar North Atlantic. Seasonal analysis reveals springtime maxima along the Gulf Stream, a northward displacement of warm anomalies in summer, and predominantly weak or negative anomalies in autumn and winter.

Long-term records (1940–2024) indicate accelerated warming since the 1990s, with near-surface air temperature increasing more rapidly than sea surface temperature, leading to a reduction in the ocean–atmosphere thermal contrast, particularly during winter.

Wintertime (2021–2024) pressure fields exhibit negative mean sea level pressure anomalies over the central subpolar North Atlantic and higher pressure along the basin periphery, suggesting a concentration and partial reorganization of the extratropical storm track. Corresponding 250-hPa wind anomalies indicate localized jet strengthening and a northward displacement of the jet axis.