Thursday, December 16, 2010

Gulf Stream Temperature Anomaly


Something interesting has been happening in the waters of the North Atlantic since the end of the Hurricane Season on 30th November 2010, writes Anthony McEvoy. 

The traditionally warm Gulf Stream appears to be cooling. Observations by NOAA (National Oceanic and Atmospheric Administration) Satellites appear to show a rapidly developing salient of cool water expanding north eastwards from the Gulf of Mexico and a similar large bulge descending south westwards from Europe. This could be interfering with the development of the Azores High and weakening it, thus affecting weather patterns over the north Atlantic.




There has also been a stubbornly warm pool of water off the north coast of Iceland that appears to be interfering with the development of the Iceland Low. Traditionally in winter this Low sits to the west of Iceland between the island and Greenland. This year however it has appeared regularly to the east of Iceland allowing exceptionally cold air to escape from the Arctic and plunge into Europe. These two anomalies combined could most likely be the cause of our persistent cold weather over Europe.

A team from the National Oceanographic Centre in Southampton has been studying temperatures and flow rates in the North Atlantic. In 2005 they have found a 30% reduction in the warm currents that carry water north from the Gulf Stream compared with the findings of surveys done in 1957, 1981 and 1992.

The Gulf Stream has shut down previously. 12,000 years ago it shut down in a period of only a few decades and led to a 5 C – 10 C drop in temperatures in Europe. There may also have been a slowing or cooling of the Gulf Stream during the “Little Ice Age” which lasted sporadically from 1300 – 1850. During this time the Thames froze regularly in winter. Scientists however don’t believe that there is an imminent chance of the Gulf Stream shutting down…..but there is always the possibility that life may imitate art. Does Hollywood know something the scientists don’t know?

If this pattern continues there is a strong possibility that January and February will be even colder.

The attached pictures show how the Gulf Stream has been cooling by the order of 0.5 – 1.0 C since the end of November. Note also the warm anomaly off the north coast of Iceland which is of the order of 5 C warmer than normal.

HERE is a link to NOAA’s Sea Temperature observation site.