Monthly Archives: January 2018

PLEA Network

4 January 2018: The first complete temperature datasets for 2017 show that last year was the third in a row of exceptionally warm years, the Copernicus Climate Change Service (C3S) implemented by the European Weather Centre (ECMWF) can announce. One data set, produced by ECMWF, shows that the global average surface air temperature exceeded 14.7°C, making 2017:

  • about 0.1°C cooler than the warmest year on record, 2016, and warmer than the previous second warmest year, 2015
  • the warmest year on record not influenced by warming El Niño conditions in the tropical Pacific
  • around 0.5°C warmer than the 1981–2010 climatological reference period
  • an estimated 1.2°C warmer than the pre-industrial value for the 18th century.

Comparable results have been obtained by C3S from a reanalysis dataset produced by the Japan Meteorological Agency (JMA). The method used to produce the datasets is to combine millions of meteorological and marine observations, including from satellites, with models to produce a complete reanalysis of the atmosphere. The combination of observations with models makes it possible to estimate temperatures at any time and in any place across the globe, even in data-sparse areas such as the polar regions. The results support the provisional announcement by the World Meteorological Organization (WMO) two months ago that 2017 was set to be among the three warmest years on record. Other datasets used in the WMO announcement, which are derived from monthly climatological data for a smaller number of long-term observing sites, are also expected to concur when they are released shortly. All datasets will contribute to the consolidated statement to be issued by WMO on 2017 temperatures. Read More here

PLEA Network

1 January 2018, Independent, Arctic warming linked to wet summers and snowy winters in the UK, scientists warn. Record wet summers and severe snowy weather in winter seen in recent years in the UK could be linked to Arctic warming, scientists have said. The UK has been hit by a number of extreme weather events in the past decade, including heavy rain in summer 2007 and 2012, the record wet and stormy winter of 2013/14 and cold and snowy winters in 2009/10 and 2010/11. Researchers compared data of recent UK extremes with the position of the North Atlantic polar atmospheric “jet stream” – a giant current of air – using a measure called the North Atlantic Oscillation (NAO) index which indicates shifts north and south. The exceptional wet summers, snowy cold snaps and mild stormy winters all corresponded with pronounced negative or positive spikes in readings of the index, showing more extreme north and southward movements of the jet stream. The researchers also linked the jet stream’s altered path – its increasing “waviness” – with a rise in summer months of areas of high pressure remaining largely stationary over Greenland, distorting the path of storms across the North Atlantic. Read More here