Geen diatitel

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Climate change in the NetherlandsAlbert.Klein
.Tank _at_ KNMI.nl UGV symposium Global Change,
22 March 2006
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Source CRU/MetOffice, UK
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• Since 1975, warming dominates in all seasons,
  except Autumn

Source Klein Tank, 2004
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Source IPCC, TAR, Chapter 2, 2001
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upper 10-ptile 1961-1990 the year 1996 lower
10-ptile 1961-1990
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upper 10-ptile 1961-1990 the year 1996 lower
10-ptile 1961-1990
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upper 10-ptile 1961-1990 the year 1996 lower
10-ptile 1961-1990
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Station De Bilt (The Netherlands)
warm nights cold nights
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Observed trends (days per decade)for 1951 to 2003
Alexander et al., J.Geophys.Res., 2006
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Day-count indices of extremes
Relation between relative trend bq/X required for
80 detection probability (5 level) and series
length N for extreme events with average return
period Tret
Source Klein Tank and Können, J. Climate, 2003
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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
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Wind study the Netherlands 1962-2002
Smits, Klein Tank, Können, Int.J.Climatol., 2005
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Observed trends for 1962-2002
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Annual precipitation Netherlands
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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
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eca.knmi.nl
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Amplified response of very wet days (trends
over last 50 yr)
Groisman et al., 2005
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Temperature
Source IPCC TAR, 2001
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5.8C
1.4C
Source IPCC AR4 simulations (partly available
at climexp.knmi.nl)
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Sea level change globally Departures in the
Eastern North Atlantic
Source Katsman, 2006
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Summer precipitation change in Hadley Centre
climate model simulations
red seasonal total precipitation
blue daily extremes
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CHALLENGE project (62 model-simulations of August
rainfall totals in NL)
simulation 19
simulation 7
Source Selten, Dijkstra, Kliphuis, et al.,
CLIVAR, 2003
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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 _at_ KNMI.nl