Publication Date:
2014-04-11
Description:
Since the start of the Holocene, temperatures in the Arctic have steadily declined. This has been accredited to the orbitally forced decrease in summer insolation reconstructed over the same period. However, we present climate modelling results here that indicate that up to 42% of the cooling in the Arctic, over the period 9–0 ka was a direct result of the desertification that occurred in the Sahara. Through a land–atmosphere teleconnection, increasing surface albedo in the Sahara leads to a regional increase in surface pressure, a weakening of the trade winds, the westerlies and the polar easterlies, which in turn reduces the meridional heat transported by the atmosphere to the Arctic. Additionally, through a series of targeted sensitivity experiments we explored the affects that using a modern cloud data set has upon mid and early Holocene climate simulations, and show that despite an apparent weakness in our model our original conclusions are robust. We conclude that interglacial climate is sensitive to changes in Sahara vegetation type, which has significance in the future debate of the response of the Sahara to climate change, considering the uncertainty surrounding future precipitation projections for this region.
Print ISSN:
1814-9340
Electronic ISSN:
1814-9359
Topics:
Geosciences
