Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: European wind variability over 140 yr   We present initial results of a study on the variability of wind speeds
across Europe over the past 140 yr, making use of the recent Twentieth Century
Reanalysis data set, which includes uncertainty estimates from an ensemble
method of reanalysis. Maps of the means and standard deviations of daily wind
speeds, and the Weibull-distribution parameters, show the expected features,
such as the strong, highly-variable wind in the north-east Atlantic. We do not
find any clear, strong long-term trends in wind speeds across Europe, and the
variability between decades is large. We examine how different years and
decades are related in the long-term context, by looking at the ranking of
annual mean wind speeds. Picking a region covering eastern England as an
example, our analyses show that the wind speeds there over the past ~ 20 yr are
within the range expected from natural variability, but do not span the full
range of variability of the 140-yr data set. The calendar-year 2010 is however
found to have the lowest mean wind speed on record for this region.

16
The categories of this paper are: stat
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
29
The categories of this paper are: funct-an