Trends and Cycles in Long Irish Meteorological Series

Abstract

We have analysed the trends in four long meteorological time series from Armagh Observatory and compared them with series available from other Irish sites. We find that although maximum and minimum temperatures have risen in line with global averages, minima have risen faster than maxima, thereby reducing the daily temperature range. The total number of hours of bright sunshine has fallen since 1885 at the four sites studied, which is consistent with both a rise in cloudiness and the fall in the daily temperature range. Over the past century, soil temperatures at both 30cm and 100cm depths have risen twice as fast as air temperature.Wavelet analysis has found significant cycles with periods of 7Á 8 years, 20Á 23 years and 30 Á 33 years in the seasonal and annual meteorological series from Armagh. Some of these cycles are clearly linked to the North Atlantic Oscillation.

The role of water vapor and solar radiation in determining temperature changes and trends measured at Armagh, 1881–2000

“…Evidence that the results presented in this study are of more than purely local significance is provided by the similarity of climate trends measured at Armagh to those at three other Irish sites with long‐term records: in all four series the periodicities appear to be linked with those of the North Atlantic Oscillation [ Butler et al , 2007]. On a larger spatial scale the increase in mean annual air temperature measured at Armagh, 0.74°C over the last century, was similar to the mean for the land surfaces of the Northern Hemisphere over the same period, 0.63°C [ Intergovernmental Panel on Climate Change ( IPCC ), 2007].…”

“…Multilinear regression analysis showed that the highest correlations and greatest climate sensitivity to both long‐ and short‐wave radiation occurred in the winter months; by contrast there was no significant relationship between the sum of the two radiation fluxes and temperatures, neither for annual nor seasonal relationships. In this connection it is noted that seasonal differences were found in the rates of the air temperature increases measured at Armagh; during the autumn and spring months the increase in temperatures exceeded those occurring in the winter and summer months and in the annual values [ Butler et al , 2007].…”

Identifying natural contributions to late Holocene climate change

“…Wavelet analysis has previously been brought into use in climate studies (e.g. Lau and Weng, 1995;Torrence and Compo, 1997;Baliunas et al, 1997;Isaksson et al, 2005, Butler et al, 2007, but until now the technique only has received limited interest from the climate community in general. The modest interest may partly be explained by the intense focus on analytic climate modelling, and partly by the fact that most papers on wavelet analysis tend to employ a difficult mathematical language.…”

Combining limnological and palaeolimnological data to disentangle the effects of nutrient pollution and climate change on lake ecosystems: problems and potential

“…In White Lough, the sediment is well dated, and Anderson et al. (2012) argue that the cycles in biogenic silica recorded in the sediments can be linked to the NAO through the correlation between the summer precipitation record from the nearby Armagh Observatory and the NAO (Butler, Garcia‐Suarez & Palle, 2007). However, from the perspective of the sediment record at White Lough, the in‐lake response is probably mediated by catchment soil processes and the competition between diatoms and cyanobacteria for nutrients.…”