Monday, August 26, 2013

New paper finds a decrease of wind speeds from 1975-2006

A paper published today in the International Journal of Climatology examines wind speeds over Turkey and finds a significant decrease over the period of study from 1975 to 2006. In addition, the paper finds that the "strengths of wind speed trends identified for the 1975–2006 period over Turkey are similar to the trends detected in wind speeds in many other regions over the earth." The paper refutes claims by climate alarmists that warming causes increases of cyclones, hurricanes, or extreme weather, and corroborates many peer-reviewed papers finding the opposite, that warming causes a decrease of wind speeds, cyclones, tornadoes, and hurricanes.

Wind speed trends over Turkey from 1975 to 2006
Filiz Dadaser-Celik*, Eda Cengiz

This study examines the spatial and temporal dynamics of wind speeds over Turkey by analysing data from 206 weather stations for a 32-year period (1975–2006). Trends in annual, seasonal, and monthly average wind speeds were determined using the Mann–Kendall trend test with the trend-free pre-whitening procedure. The strengths of trends were estimated by calculating the Sen's slope. The possible causes of wind speed changes were discussed. The analysis showed that the majority of the stations (73%) in Turkey had average wind speeds between 1.6 and 3.3 m s−1 during the 32-year period. From 1975 to 2006, 72% of stations had downward trends in annual average wind speeds. Downward trends were statistically significant at the 0.05 level for 62%. Significant upward trends were detected in only 16% of 206 stations. The rate of change in annual average wind speed data was on average −0.014 m s−1 year−1. The trends detected in monthly average wind speed data were mostly downward with an average strength between −0.007 and −0.017 m s−1 year−1. The directions and strengths of wind speed trends identified for the 1975–2006 period over Turkey are similar to the trends detected in wind speeds in many other regions over the earth. The changes in wind speeds in Turkey are most strongly related with the changes in general circulation patterns and air temperatures. The effects associated with changes in surface roughness and data quality are minor compared to other two factors.

1 comment:

  1. Another new paper finding a slight decrease in wind speeds

    http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-13-00652.1?af=R

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