6 research outputs found
Recommended from our members
Changes in the variability and periodicity of precipitation in Scotland
This paper analyses the temporal and spatial changes in the amount and variability of rainfall in Scotland. The
sequential MannâKendall test reveals that total annual precipitation has increased across Scotland since the 1970s with
increasing trends in variability beginning between the mid-1960s and the mid-1970s. Whilst temporally consistent
increasing trends in precipitation totals prevail in the West, many weather stations in the East have experienced
subsequent trend turning points in the following two decades, explaining the larger magnitude of the trends in western Scotland in recent decades. Trend analyses on six measures of rainfall variability indicate an increase in rainfall variability during the period 1961â2000, as measured by the intra-annual variance, the winter to summer precipitation ratio and the annual cumulative sum range, with decreasing trends observed in the number of dry days. Periodicities associated with
the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation could explain the observed temporal variability of
rainfall
Recommended from our members
Solar Influence on Global and Regional Climates
The literature relevant to how solar variability influences climate is vastâbut
much has been based on inadequate statistics and non-robust procedures. The common
pitfalls are outlined in this review. The best estimates of the solar influence on the global
mean air surface temperature show relatively small effects, compared with the response to
anthropogenic changes (and broadly in line with their respective radiative forcings).
However, the situation is more interesting when one looks at regional and season variations
around the global means. In particular, recent research indicates that winters in Eurasia
may have some dependence on the Sun, with more cold winters occurring when the solar
activity is low. Advances in modelling ââtop-downââ mechanisms, whereby stratospheric
changes influence the underlying troposphere, offer promising explanations of the observed
phenomena. In contrast, the suggested modulation of low-altitude clouds by galactic
cosmic rays provides an increasingly inadequate explanation of observations