1. HOMOGENEITY OF THE ECA TEMPERATURE DATA
Janet Wijngaard
Albert Klein Tank
BUDAPEST, SEPTEMBER

2. HomogeneityTests
Standard Normal Homogeneity Test (SNHT, Alexandersson)
Range test (Buishand)
Von Neumann ratio

3. Testing method No reference stations used - stations are diverse
Annual DTR series tested artificial changes opposite effect - natural changes same effect

4. CONCLUSIONS Test results for the examples are satisfactory
Summarised results for SNHT, Range-test and Von Neumann Ratio overview of homogeneity
Meta data should be used to take full advantage of the ECA data set

5. Von Neumann Ratio for Eelde Groningen
N= period:
N= period:

6. SNHT
Range test
Von Neumann Ratio