Naked Science Forum

Life Sciences => The Environment => Topic started by: syhprum on 02/07/2018 16:49:39

Title: Do hot dry summers occur in a 14 year cycle?
Post by: syhprum on 02/07/2018 16:49:39

The hottest driest summers that stick in my memory were 1948 and 1976 28 years apart, does anyone remember 1962 ,1990 or 2004 which could indicate a 14 year cycle as 2018 seems to be turning out another one with no rain forecast in the next 14 days.

Title: Re: Do hot dry summers occur in a 14 year cycle?
Post by: Bored chemist on 02/07/2018 17:00:14

Feel free to check
https://www.metoffice.gov.uk/pub/data/weather/uk/climate/stationdata/sheffielddata.txt
 etc
from
https://www.metoffice.gov.uk/public/weather/climate-historic/#?tab=climateHistoric

But I suspect that people would have noticed.

Title: Re: Do hot dry summers occur in a 14 year cycle?
Post by: alancalverd on 03/07/2018 07:02:13

There are several near-cyclic phenomena involved including the "11 year" sunspot cycle (actually  9 - 14 years) so it's not surprising that there could be a "resonance" effect every 14 years or so. Various species seem to breed on multi-year cycles, presumably with some relation to weather, so we might get a plague of butterflies, greenfly or ladybirds in the UK this year - I'm betting on ladybirds.

Title: Re: Do hot dry summers occur in a 14 year cycle?
Post by: evan_au on 03/07/2018 12:57:41

In the 19th century, an economist suggested that sunspot cycles might affect the economy.

Subsequent studies have found no link, and economists now contemptuously use the term "sunspot" to refer to any random and unpredictable variable that may affect the economy.
https://en.wikipedia.org/wiki/Sunspots_(economics)

Of course, with what we now know about the Maunder minimum, we could suggest that perhaps the economists were looking on too short a timescale, and using the wrong metric? Extended periods with little or no sunspot activity have been associated with lower-than average temperatures in Europe - including the Thames River freezing over.
But this is an association, without a proven causation.
https://en.wikipedia.org/wiki/Maunder_Minimum#Little_Ice_Age