The BBC reports on a new paper in Environmental Research Letters which actually brings solar influence back into the climate picture.
“We show that some predictive skill may be obtained by including the solar effect” says this new paper.
Yes Indeed!
But how was the sun’s influence ever discarded in climate models??
Britain is set to face an increase in harsh winters, with up to one-in-seven gripping the UK with prolonged sub-zero temperatures, a study has suggested. The projection was based on research that identified how low solar activity affected winter weather patterns.
“We could get to the point where one-in-seven winters are very cold, such as we had at the start of last winter and all through the winter before,” said co-author Mike Lockwood, professor of space environment physics at the University of Reading.
Using the Central England Temperature (CET) record, the world’s longest instrumental data series that stretches back to 1659, the team said that average temperatures during recent winters had been markedly lower than the longer-term average.
“The mean CET for December, January and February for the recent relatively cold winters of 2008/09 and 2009/10 were 3.50°C and 2.53°C respectively,” they wrote.
“Whereas the mean value for the previous 20 winters had been 5.04°C.
“The cluster of lower winter temperatures in the UK during the last three years had raised questions about the probability of more similar, or even colder, winters occurring in the future.”
Professor Lockwood was keen to point out that his team’s paper did not suggest that the UK and mainland Europe was about to be plunged into a “little ice age” as a result of low solar activity, as some media reports had suggested.
M Lockwood et al 2011 Environ. Res. Lett. 6 034004 doi: 10.1088/1748-9326/6/3/034004
The solar influence on the probability of relatively cold UK winters in the future
M Lockwood, R G Harrison, M J Owens, L Barnard, T Woollings and F Steinhilber
Abstract: Recent research has suggested that relatively cold UK winters are more common when solar activity is low (Lockwood et al 2010 Environ Res Lett 5 024001). Solar activity during the current sunspot minimum has fallen to levels unknown since the start of the 20th century (Lockwood 2010 Proc. R. Soc. A 466 303–29) and records of past solar variations inferred from cosmogenic isotopes (Abreu et al 2008 Geophys Res Lett. 35 L20109) and geomagnetic activity data (Lockwood et al 2009 Astrophys. J. 700 937–44) suggest that the current grand solar maximum is coming to an end and hence that solar activity can be expected to continue to decline. Combining cosmogenic isotope data with the long record of temperatures measured in central England, we estimate how solar change could influence the probability in the future of further UK winters that are cold, relative to the hemispheric mean temperature, if all other factors remain constant. Global warming is taken into account only through the detrending using mean hemispheric temperatures. We show that some predictive skill may be obtained by including the solar effect.
Depiction of the 1683 Thames' frost fair (Getty Images)
Professor Lockwood said it was a “pejorative name” because what happened during the Maunder Minimum “was actually nothing like an ice age at all”.
“There were colder winters in Europe. That almost certainly means, from what we understand about the blocking mechanisms that cause them, that there were warmer winters in Greenland,” he observed. “So it was a regional redistribution and not a global phenomenon like an ice age. It was nothing like as cold as a real ice age – either in its global extent or in the temperatures reached. “The summers were probably warmer if anything, rather than colder as they would be in an ice age.” He added that the Maunder Minimum period was not an uninterrupted series of cold, harsh winters.
Data from the CET showed that the coldest winter since records began was 1683/84 “yet just two year later, right in the middle of the Maunder Minimum, is the fifth warmest winter in the whole record, so this idea that Maunder Minimum winters were unrelentingly cold is wrong”.
He explained that a similar pattern could be observed in recent events: “Looking at satellite data, we found that when solar activity was low, there was an increase in the number of blocking events of the jetstream over the Atlantic. “That led to us getting colder weather in Europe. The same events brought warm air from the tropics to Greenland, so it was getting warmer. “These blocking events are definitely a regional redistribution, and not like a global ice age.
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