North-Atlantic cyclones

Over the European continent, the North-Atlantic cyclones weaken during their eastward propagation, but often they cause the weather to be quite variable. That means, a very diverse but usually heavy cloud cover with occasional precipitation prevails over the Baltic Sea. It is generally moist, cool, and rather windy. The global west-wind jet carries moist and cool air masses from the North Atlantic and the North Sea to central and northern Europe (Nehring et al., 1990). This leads to a predominantly maritime influence on the Baltic Sea region. This... 

FIGURE 4.6 A typical weather map showing Europe and the North Atlantic. The closed curves are called isobars and are contours of constant atmospheric pressure. Regions of low pressure (L) are called cyclones and regions of high pressure (H) are called anticyclones. 

Climate extremes will intensify (heat waves, heavy showers, etc.) the intensity of tropical cyclones (typhoons) will increase due to further SST rise at low latitudes meridional circulation in the North Atlantic will decrease, on average, by 25% extra-tropical cyclones will shift toward the poles. 

Hanshaw M.N. Lozier M.S. and Palter J.B. (2006). The Integrated Impact of Tropical Cyclones on Sea Surface Chlorophyll in the North Atlantic. American Geophysical Union, Fall Meeting 2006, abstract A13A-0878, Washington, 2006AGUFM.A13A0878H. 

Acknowledgments This work has been supported by the German Research Foundation (DFG) in the framework of the project SCHL499-2 and the Sonderforschungsbereich 512 Cyclones and the North Atlantic Climate System . This work is a contribution to COST-728 Action. 

Its center lies at an altitude of about 5 km, that is, in the center of the troposphere, and is frequently located over the Baltic Sea. The location, the strength, and the cyclonic or an ticy clonic character of this j et stream determines the weather of the Baltic Sea. Two global action centers over the North Atlantic—the Icelandic Low and the Azores High—regulate its dynamics. North Atlantic lows with their fronts and wedges at intermediate altitudes are very often embedded in this westerly wind system. Usually, they move rapidly from west to east across the Baltic Sea and its coasts. 

FIGURE 5.16 Seven years running means of detrended, standardized series [mean = 0, STD = 1, given in standard deviations (STD)] of the WIBIX (bold line), the winter frequency (JFM) of eastward traveling cyclones with core pressures lower than 950 hPa (FEC, thin line) over the North Atlantic-European sector (30-90°N, 60 W-60 E) compiled by Schinke (1993), and the averaged sea surface temperature anomaly (SSTA, broken line) in the area between 47.5 82.5 N and 22.5 W- 47.5 E the SSTA series results from the well-known Kaplan series, (NOAA, 2006c). 

Schinke, H., 1993. On the occurrence of deep cyclones over Europe and the North Atlantic in the period 1930-1991. Beitrage zur Physik der Atmosphare, 66, 223-237. 

Beckmann, W., Auras, A. Hemleben, C. 1987. Cyclonic coldcore eddy in the eastern North Atlantic. III. Zooplankton. Marine Ecology Progress Series, 39, 165-173. 

Offshore waters forecasts for the Southwest North Atlantic, Caribbean Sea, and Gulf of Mexico These are now-casts through 36-h forecasts (updated every 6 h) and cover marine warnings for gale, storm, and tropical cyclone conditions—as weU as information on reduced visibility and other marine hazards. 

Neumann, C.J. et al.. Tropical cyclones of the North Atlantic Ocean, 1871-1977, National Climatic Center, US Department of Commerce, National Oceanic and Atmospheric Administration, Ashville, North Carolina, 1978. 

Hurricanes predominantly effect the Gulf and Atlantic coasts of North America. These weather systems can also occur in other regions of the world where they may be identified by other names such as typhoons or tropical cyclones. Hurricanes that effect North America are spawned over the western Atlantic Ocean and usually develop between July and September. These weather systems are very powerful and can affect the weather pattern for hundreds of miles (kilometers) from the center of the storm. The National Weather Service can usually provide a 2-3 day warning to those areas in the expected path of a hurricane. 

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