A history of rain gauges

✍ Scribed by Brian Giles

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 813 KB
• Volume: 65
• Category: Article
• ISSN: 0043-1656
• DOI: 10.1002/wea.656

✦ Synopsis

It is also possible to calculate rolling 365day (366 when including 29 February) CET beginning in 1772 when daily CET commences. For the 1778/1779 warm event, the highest rolling value was 10.86 °C ending on 14 November 1779. The average temperature for the 366 days ending 21 May 1948 was also 10.86 °C. Annual values calculated from daily data are typically 0.03 degC higher than those calculated from monthly averages, mainly because the latter method gives equal weight to February even though it is a short month. So we calculate 11.66 °C from the daily data for the 365 days ending 30 April 2007 and 11.68 °C for the 365 days to 2 May 2007, the highest in the 238-year record.

We have also calculated the coldest rolling year CET: this was 7.23 °C ending on 8 December 1879. The value for the calendar year 1879, based on the dailies, was 7.43 °C. Since the beginning of the twentieth century, the only rolling annual CETs below 8 °C have been in 1962/1963 when the lowest was 7.67 °C for the 365 days ending 1 March 1963.

Although we have cited these yearly CET values to two decimal places, we note that the standard error of estimate, which mainly arises from calibration uncertainty and geographical sampling error, is 0.09 degC even in the period 1878 onwards when there have been three or four measuring stations (Parker and Horton, 2005). Before 1878, only single stations were used, and the annual standard errors are of the order of 0.15 degC back to the 1720s, and even more before then (Parker, 2010).