Global temperatures: Set for a sharp fall?
The El Nino which has helped to cause near record global heat so far this year is now history, as sea temperatures in equatorial regions of the Pacific continue to fall. The following 2 images illustrate the change the has occurred over the last few months to sea surface temperatures in the Equatorial region of the Pacific.
Most models, as you can see below, now predict La Nina conditions (SST anomalies less than or equal to -0.5oC in the Nino region) to develop during through the rest of summer and to continue into 2011 causing a sharp cooling of global temperatures later this year and into next.
Just how fast will be crucial in deciding whether 2010 will be hotter than the hottest year on record, which was set in 1998, as defined by the UK Hadley Centre, The World Meteorological Organisation (WMO) and UAH Satellite data.
During a La Niña, trade winds in the western equatorial Pacific are stronger than normal, and the cold water that normally exists along the coast of South America extends to the central equatorial Pacific. This colder water directly translates into colder global temperatures, just as warm waters associated with an El Nino directly translates into warmer global temperatures.
The Last El nino comparable to this one in 1997/1998 was followed by a La Niña which began developing in the middle of 1998 - and was persistent into the winter of 2000. According to the Japanese institute for Marine Earth Science, the La Nina condition developing now might last for a longer-than-normal period.
If history repeats itself, not only could 2011 be much cooler than 2010, but that cool bias could extend into 2012 too.
The picture above illustrates how their global model sees the world surface air anomalies between Dec 2010 and Feb 2011. Note on average how much of the land is actually cooler than normal by that time.
Hello, I’m Paul Hudson, weather presenter and climate correspondent for Ö÷²¥´óÐã Look North in Yorkshire and Lincolnshire. I've been interested in the weather and climate for as long as I can remember, and worked as a forecaster with the Met Office for more than ten years locally and at the international unit before joining the Ö÷²¥´óÐã in October 2007. Here I divide my time between forecasting and reporting on stories about climate change and its implications for people's everyday lives.
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