Alexander, L.V; Zhang, X; Peterson, T.C; Caesar, J; Gleason, B; Tank, A.K; Haylock, M; Collins, D; Trewin, B; Rahimzadeh, F; Tagipour, A; Ambenje, P; Kumar, K.R; Revadekar, J; Griffiths, G; Vincent, L; Stephenson, D; Burn, J; Aguilar, E; Brunet, M; Taylor, M.A; New, M; Zhai, P; Rusticucci, M; Vazquez-Aguirre, J.L
Author Affiliation, Ana.
Global observed changes in daily climate extremes of temperature and precipitation
Journal of Geophysical Research
Date of Publication
Also as an electronic citation at the url provided.
A suite of climate change indices derived from daily temperature and precipitation data were calculated, primarily focusing on extreme events. By setting an exact formula for each index and using specially designed software, analyses done in different countries have been combined seamlessly. We present the most up to date and comprehensive global picture of trends in extreme temperature and precipitation indices using results from a number of workshops held in data sparse regions and high quality station data supplied by numerous scientists world wide. Probability distributions for a subset of approximately 200 temperature and 350 precipitation stations were analysed for the periods 1901-1950, 1951-1978 and 1979-2003. The analysis shows a significant warming throughout the 20th century. Temperature differences are particularly pronounced between the most recent two periods and for those indices related to minimum temperature. An analysis of those indices for which seasonal timeseries are available shows that these changes occur for all seasons although they are least pronounced for September to November. Precipitation indices show a tendency towards wetter conditions. Seasonal and annual indices for the period 1951 -2003 were gridded using an angular distance weighting technique and trends in the gridded fields were tested for significance. Results showed widespread significant changes in temperature extremes, especially for those indices derived from daily minimum temperature. Over 70% of the global land area sampled showed a significant decrease in the annual occurrence of cold nights and a significant increase in the annual occurrence of warm nights. Some regions experienced a more than doubling of these indices. This implies a positive shift in the distribution of daily minimum temperature throughout the globe. Changes in daily maximum temperature are less marked, implying that our world is becoming considerably less cold rather than considerably hotter. Precipitation changes were much less coherent but annual precipitation did show a widespread significant increase.....