Monthly wind directional indices based on ships logbooks observations

DESCRIPTION: Daily data of wind direction over the English Channel based on direct marine observations derived from Royal Navy ships' logbooks (1685-1870) and ICOADS v3.0 (1750-2014) datasets has been used to build four directional indices (one for each cardinal wind direction).

We provide four instrumental-based monthly indices defined as the proportion of days per month (in % respect to the total number of available days for each month) with wind blowing from a particular cardinal wind direction. DATA: Each index is defined as the percentage of days in a month with wind blowing from a particular cardinal wind direction with respect to the total number of available (i.e., non missing) days in the month) No: Number of available days (i.e., with at least one wind observation) in a month (in % with respect to the total number of days in the month).