An analysis of rainfall across the British Isles in the 1870s

Abstract

has been published in nal form at http://dx.doi.org/10.1002/joc.4184. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. which these very high rainfall totals were generated. The normally wettest locations in the British Isles, i.e. the uplands in the north and west, were not unusually wet in the 1870s whereas locations with extremely high rainfall totals (relative to mean annual rainfall) tended to be further south and east in the lowlands. These exceptionally high totals were associated with a high frequency of cyclonic weather types and high scores for atmospheric vorticity; at the same time, the frequency of anticyclonic weather and of westerly winds tended to be very low. The winter of 2013-14, remarkably wet in southern England, was somewhat different in that the frequency of westerly air flow and resultant flow were both very high but so too were vorticity and the frequency of cyclonic weather types; the year 2012 experienced similar atmospheric conditions. The results confirm the importance of cyclonic weather for large rainfall totals across much of the British Isles; strong westerly winds seem only to favour the uplands and north-west coastal locations..

A cyclone climatology of the British‐Irish Isles 1871–2012

“…Cyclone counts were found to correlate most strongly with the BIBF, such that increased regional blocking translates into fewer cyclonic circulation days. This fits with the summer‐only investigation of Dong et al () and agrees with the negative correlation between cyclonic and anticyclonic LWTs noted by Burt et al (). Figure (left) demonstrates that this relationship generally holds when the seasonal climatological cycle is assessed: the blocking minimum in summer, characteristic of conditions across the north‐eastern margin of Europe (Figure , right), coincides with the summer cyclone maxima.…”

“…The sign of relationship is consistent with analyses using the cyclonic LWT (e.g. Wilby et al , ; Burt et al , ). Negative correlation may reflect either slower moving cyclonic systems during NAO negative years (subdued westerly circulation), or the passage of more cyclonic weather systems, as both processes could contribute to a higher number of cyclone days for our domain.…”

“…This would also account for the more spatially homogenous summer correlation field in Figure . Regardless of the physical processes driving correlations, cyclone frequency has already been linked to spatially extensive flooding episodes (Wilby and Quinn, ) due to high rainfall amounts across the BI associated with cyclone passage (Burt et al , ). We emphasize that these conclusions are perhaps most appropriate for summer based on the evidence presented here.…”

Persistence of Hydrometeorological Droughts in the United Kingdom: A Regional Analysis of Multi-Season Rainfall and River Flow Anomalies

“…Spraggs et al 2015). features include the previously reported runs of exceptionally wet years in the 1870s (Burt et al, 2014), dry years in the 1850s (Barker et al, 2004) and at the end of the nineteenth century (Marsh et al, 2007). Persistent dry-spells are also evident in the 1770s and 1780s but these have received relatively little attention to date.…”

A hydrogeomorphic assessment of twenty‐first century floods in the UK

“…For example, during April–June 2012 the northwest Highlands and Islands experienced extremely dry conditions with record low flows on some rivers (CEH, ), in contrast to very wet conditions and severe flooding across the rest of the UK. Similar patterns are also evident for some very wet years during the 1870s (Burt et al, ). These differences are apparent in the Stornoway rainfall record in that periods of high summer rainfall in east Scotland are much less marked than further west (e.g.…”