Changes in wind speed may have caused abrupt meltdowns

July 21st, 2008 - 5:04 pm ICT by IANS  

Washington, July 21 (IANS) Small changes in surface winds may have possibly played a substantive role in abrupt climate change during the last glacial period, says a study. Conducted by Complutense University of Madrid (UCM) and Potsdam-Institute for Climate Impact Research, Germany, the study concluded that there is a precise point from which a small variation in sea winds speeds corresponds to a dramatic change in the Atlantic circulation intensity.

Marisa Montoya of UCM said: If the glacial climate had been in the vicinity of that point, small wind changes could have caused sudden and significant climatic changes during that period.”

The study was based on climatic simulations called Last Glacial Maximum (LGM) - period of maximum extension of ice-sheets over 21,000 years ago.

These simulations have demonstrated the existence of a threshold after which a small change in wind speed causes disproportionately large changes in the sea current speed.

The results indicate that these changes in wind speed could have had a particularly important role in the abrupt climatic change of the last ice age.

Climate simulation of the LGM is one of the principal challenges for experts in this area. The comparison of results from these simulations with climatic reconstruction permit the evaluation of the climatic models in conditions independent from the ones used for their design.

The results confirm the relevance of the small variations and help substantiate the hypothesis about the physical mechanisms responsible for the climatic changes observed in the reconstructions.

Tags: , , , , , , , , , , , , , , , , , , ,

Posted in World |