Tuesday, 18 August 2015

“Googly Summer” or the true “Year without a Summer”?

The year 1816, following a major volcanic eruption, is often referred to in US and European history chronicles as “The year without a Summer” as Western Europe and the United States went through a summer where – at least supposedly in the absence of large-scale climatological data – frosts and snows occurred all through the “summer”. What data does exist does suggest a very cool summer in these regions, but nothing to suggest a major global cooling.
As we can see above, the exceptionally cool conditions in Western Europe were balanced by hotter-than-normal conditions further east. This may suggest rain was the culprit behind major agricultural problems, since cool weather on a western flank and hot on an eastern one suggests exceptionally wet conditions at the boundary between the two anomalies, as can be seen here for July 1993 in the US:
Average temperatures for the conterminous US in July 1993. Note the record cool in the Northwest (as much as 9.1˚F or 5.1˚C below normal in southern Idaho – an anomaly which has a virgin or constant-greenhouse-forcing return period certainly far beyond 121 years) and the very hot weather in the Southeast

Rainfall for the conterminous US in July 1993. Note the heavy rainfall in Kansas, Nebraska, Iowa and Missouri near the boundary between much-hotter and much-cooler than normal conditions.
The impression if often given that 1816 is without analog. However, from my knowledge of old county cricket I was aware 1907 was the coolest cricket season in England since the record cool and wet summer of 1879, but recently I found that Winnipeg averaged an amazing 4.3˚C. This is as much as 6˚C cooler than Winnipeg’s virgin mean May temperature – an astonishing anomaly for a month in the hotter half of the year. As can be seen below, anomalies for May 1907 were even larger over northern Minnesota:
Conterminous US temperature anomalies for May 1907. Note the extreme cool in the Upper Midwest, where many places averaged below freezing overnight.
In fact, the April to September half-year was astonishingly cool over the Lower 48 (certainly the coolest since 1895), though the unusual thing is that it followed a winter that was very mild south of the northern tier of states:
Indeed, the 1906/1907 winter is the sole pre-Lonie-Report winter remaining as of 2015 among the top ten warmest in Arizona, and despite the global warming produced by Australian greenhouse emissions still remains the hottest winter on record in Texas and New Mexico. The winter was also extremely wet except in the Northeast and Deep South.

Although it’s often the case that temperature anomalies in the contiguous US do not reflect global trends (e.g. March 1946) the summer of 1907 seems not to follow such a pattern, being cool to very cool almost everywhere with reliable data. May 1907’s extreme cool (if the base period on the top map is manifestly outside the virgin period and unnecessarily influenced by Australian car and coal pollution) can be seen to extend well into the Arctic Circle.

The extremely cool summer in the US and Britain is hardly counterbalanced at all – like we would expect it to be in the maps for the 1906/1907 winter, the summer of 1816, and July 1993. It is true that there is a hotter-than-normal area just west of the Urals, but unlike many more famous months of simultaneous unusually cool weather in the US and Europe, there is no markedly hotter-than-average weather over the Labrador or Bering Seas. This suggests 1907 really was a “year without a summer” on quite a wide scale, though global temperature data do not show this as far as I am aware – the winter of 1906/1907 was extremely cold in southeastern Europe, Canada and Greenland, but very mild in Scandinavia and northwestern Russia.

It’s interesting to see that this “year without a summer” saw googly bowlers – expected to be at their best in a hot and dry summer – do so well. It’s almost as if the extreme cool weather did not make pitches softer as would be expected, especially as if it was windy they might have dried out well as is indicate by the high proportion of finished matches for a summer with only 53 dry days out of 123.

It may also have helped Arthur Fielder gain his surprising return of 172 wickets in an era when fast bowlers tended to be valueless in wet weather – if this very cool summer and improved drainage made getting a foothold easier, it makes sense Fielder could against weaker batsmen do so well.

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