1. HOMOGENEITY OF THE ECA TEMPERATURE DATA
Janet Wijngaard
KNMI, The Netherlands
PISA, October

3. 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

9. HomogeneityTests No reference stations used: Four tests applied:
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

11. 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

12. Testing Variables Diurnal Temperature Range
annual mean
annual standard deviation of day-to-day changes
Annual number of wet days (>1 mm)