A1088
Title: Nonparametric tests based on records to detect trends in the upper tail of climate series
Authors: Ana C Cebrian - University of Zaragoza (Spain) [presenting]
Jorge Castillo-Mateo - University of Zaragoza (Spain)
Jesus Asin - University of Zaragoza (Spain)
Abstract: There is clear evidence of global warming in mean temperature. However, not only changes in the mean are important. Changes in the tails of the distributions are also relevant, and the occurrence of hot extremes has serious consequences on human health, agriculture, etc. Some nonparametric tests are presented, based on the theory of records, which are useful to quantify and assess the existence of trends (global warming) in the upper tail of a temperature series. The tests are based on the number of records up to time t and the asymptotic normal distribution of these variables, regardless of the distribution of the original series. Some modifications of the basic statistic, splitting the series and using different types of records (lower and upper and forward and backward records) are proposed to increase the power of the tests. Since global warming is a spatial phenomenon, another test is developed to be applied in a spatial framework. These tests are applied to analyze the effects of global warming in the upper tails of different types of temperature series in a set of locations in the North-East of Spain.
