I recently decided to analyse my records of wind speeds, the most accurate go back to the year 2000 when my anemometer was moved to a very high position, well above roof height. The initial results gave me concern as recent years have shown a decline in wind speed-readings. I had wondered if the repeated attack on the instrument by a rogue rook, two years ago, had damaged the unit.
My equipment captures data every five seconds and from these records I find that there has been a downward trend in average annual wind speeds since 2007 – the fall being most notable for the last two / three years.
|
2001 |
2002 |
2003 |
2004 |
2005 |
2006 |
2007 |
2008 |
2009 |
2010 |
|
4.3 |
4.6 |
4.3 |
4.3 |
4.4 |
4.3 |
4.1 |
3.9 |
3.3 |
3.1 |
Looking specifically at readings in the winter (meteorological) period, December 1st to February 28th, I discovered a reduction in gusts of 20mph +, by an average of four per year. The statistics for gusts of 30mph + produced a reduction of three per year.
