Date post: | 20-Jan-2018 |
Category: |
Documents |
Upload: | jared-simon |
View: | 218 times |
Download: | 0 times |
“Climate change in the Netherlands”
Albert.Klein.Tank @ KNMI.nl
UGV symposium Global Change, 22 March 2006
Relation between relative trend bq/X required for 80% detection probability (5% level) and series length Nfor extreme events with average return period Tret
Source: Klein Tank and Können, J. Climate, 2003
21365~ retTXbq
6x
23~ NXbq
3x
Day-count indices of extremes
Geostrophic winds based on pressure triangles; blue circles are 95th and red crosses 99th percentiles (standardized units)
updated from: Alexandersson et al., Climate Res., 2000
Precipitation fraction due to very wet days
1) Identify very wet days using a site specific threshold = 95th percentile at wet days in the 1961-90 period
2) Determine fraction of total precipitation in each year that is due to these days
3) Trend analysis in series of fractions
Summer precipitation change inHadley Centre climate model simulations
blue = daily extremes
red = seasonal total precipitation
Source: Selten, Dijkstra, Kliphuis, et al., CLIVAR, 2003
simulation 19simulation 7
CHALLENGE project(62 model-simulations of August rainfall totals
in NL)
KNMI will soon present new climate change scenarios for the Netherlands, which replace the WB21 scenarios from 2000:
29 May 2006
THANKS !
htpp://eca.knmi.nl
http://www.knmi.nl/scenarios
mailto: Albert.Klein.Tank @ KNMI.nl