Regional climate change over the North Atlantic may not be accurately predicted by climatologists.
This is because computer model simulations have not precisely included the changes in air pressure that had occurred in the Greenland region over the past 30 years.
According to a recent research, this deficiency may imply that regional climate predictions for the UK as well as parts of Europe may possibly be inaccurate.
Upon comparing real data with simulation data over a period of 30 years, researchers discovered that the simulations on average revealed a somewhat decreasing air pressure in the Greenland area, when actually, the true data revealed a substantial increase in high air pressure—or the supposed ‘Greenland blocking’—during the time of the summer months.
Climate scientists across the globe extensively use these simulations as a basis for forecasting the climate change in the coming days.
These findings raise some important questions regarding the accuracy of regional climate projections both in the UK and the adjoining parts of Europe, because these regions have meteorological conditions that are closely associated with changes in air pressure over the Greenland region.
Researchers also caution that if the air pressure in the Greenland region continues to strengthen over the next few years, then record wet summers in Wales and England like those experienced in 2012 and 2007 may turn out to be more frequent. However, such a trend may not be forecasted owing to incorrect regional climate simulations.
Furthermore, the study, performed by the University of Liège in Belgium and the University of Lincoln, UK, reached a conclusion that present models of melting on the Greenland Ice Sheet—a massive body of ice covering over 80% of the Greenland surface—may considerably underrate the global sea-level rise predicted by 2100.
The study was headed by Professor Edward Hanna along with Dr Richard Hall, both from the University of Lincoln’s School of Geography, and Dr Xavier Fettweis from the University of Liège.
Until now, no one has systematically examined the projections to see how they represent the last few decades and future changes – up to the year 2100 – from a Greenland regional perspective.
Previous work reported a tendency for global warming to result in a slightly more active jet stream in the atmosphere over the North Atlantic by 2100 but our results indicate we may actually see a somewhat weaker jet, at least in summer.”
Professor Hanna, Lead Researcher
This is the first study to make a systematic comparison between the observational data of air pressure changes over the Greenland region and the global climate model data.
The study titled “Recent changes in summer Greenland blocking captured by none of the CMIP5 models“ has been reported in The Cryosphere; the European Geosciences Union journal.