130 likes | 319 Views
HOMOGENEITY OF THE ECA TEMPERATURE DATA. Janet Wijngaard KNMI, The Netherlands PISA, 16-20 October. High quality data. Climate variability and extremes analysis
E N D
HOMOGENEITY OF THE ECA TEMPERATURE DATA Janet Wijngaard KNMI, The Netherlands PISA, 16-20 October
High quality data • Climate variability and extremes analysis • What about the quality of the data? Annual DTR series: - artificial changes opposite effect - natural changes same effect
HomogeneityTests • No reference stations used: • stations are too diverse and coarse network • Four tests applied: • Standard Normal Homogeneity Test (Alexandersson) • Buishand Range test, based on cumulative sums • Pettitt test, non-parametric (Sneyers) • Von Neumann ratio
CONCLUSIONS • Test results: first indication for homogeneity • Meta data should be used to verify results • Quality/Homogeneity check important take full advantage of the ECA data set • ECD
Testing Variables • Diurnal Temperature Range • annual mean • annual standard deviation of day-to-day changes • Annual number of wet days (>1 mm)