Figure 6.
The horizontal axis shows years from 1960 to 2020. The vertical axis represents wind speed at 10 metres elevation in metres per second and ranges from about 1.4 to 3.0. Three seasonal data series are plotted. Dry season wind speed generally varies between about 1.5 and 2.8 metres per second. Transition season wind speed typically ranges between about 1.8 and 2.9 metres per second. Wet season wind speed is lower overall and usually ranges between about 1.4 and 2.3 metres per second. Dotted trend lines indicate long term trends for each season. The dry season slope equals minus 0.09 metres per second per decade with a confidence interval from minus 0.12 to minus 0.06. The transition season slope equals minus 0.03 metres per second per decade with a confidence interval from minus 0.07 to 0.01. The wet season slope equals minus 0.04 metres per second per decade with a confidence interval from minus 0.07 to minus 0.01. The plotted values fluctuate through time while the trend lines indicate gradual decreases in wind speed across the seasons.Regional average wind speed and trends per decade (1960–2020) with 95% confidence intervals for dry, transition and wet seasons, in the Nahouri province, based on TerraClimate data