The role of increasing temperature variability in European summer heat waves
-
Upload
katelyn-malone -
Category
Documents
-
view
28 -
download
0
description
Transcript of The role of increasing temperature variability in European summer heat waves
The role of increasing temperature variability in European summer heat waves
Christoph Schär, Pier Luigi Vidale, Daniel Lüthi, Christoph Frei, Christian Häberli, Mark A. Liniger & Christof Appenzeller
Literaturseminar 30. April, 2004
Overview Luterbach et al: European
temperature trends and extremes since 1500
Summer 2003 data
Schär et al: Increasing temperature variability in European heat waves
Literaturseminar 30. April, 2004
Luterbacher et al: European mean temperature since 1500
- warmest winter: 1989/90 T = +2.4°C
- warmest decade: 1989-98 T = +1.2°C
(second warmest 1733-42 T = +0.45°C)
- linerar temperature trend for 20th century:
+0.08°C 0.07°C per dec.
Winter
Literaturseminar 30. April, 2004
Luterbacher et al: European mean temperature since 1500
Summer
- warmest summer: 2003 T = +2.0°C
- warmest decade: 1994-03 T +1.2°C
- conspicuous: warming trends of up to 0.7°C 0.20°C per decade can be observed 1731-57, 1923-47, and 1994-2003
Literaturseminar 30. April, 2004
Luterbach et al: European mean temperature since 1500
Literaturseminar 30. April, 2004
Summer 2003 Data Warmest summer in the last 500 years in
Europe (June, July, August) Sub tropic high pressure belt shifted
north over southwestern Europe Warm air masses pushed north
Unusually small amounts of precipitation during spring and summer months
Literaturseminar 30. April, 2004
Temperature anomalysummer 2003
Literaturseminar 30. April, 2004
Deviation from the avg temp (1876-2000) in Karlsruhe
Literaturseminar 30. April, 2004
Satellite views
Satellitenbild, 8.8.2003, 12:09 UTC, NOAA 16, VISQuelle: Inst. f. Meteorologie, FU Berlin
Satellitenbild, 8.8.2003, 18:00 UTC, MET 7, IR Quelle: Fak. f. Ingenieurwissenschaften, Univ. Ulm
Literaturseminar 30. April, 2004
Summary: 2003 data
Literaturseminar 30. April, 2004
Summary: 2003 dataComparison to 1876-2000 avg
Literaturseminar 30. April, 2004
Schär et al: European temperature anomaly
Literaturseminar 30. April, 2004
Distribution of Swiss monthly temperatures 1864-2003
Literaturseminar 30. April, 2004
Monthly Temp anomalies (J-D) 1864-1923 & 1941-2000
Literaturseminar 30. April, 2004
Relative frequency change between the two periods
Literaturseminar 30. April, 2004
Estimation of return period Reference period = 1864-2000
return period several million years
Accounting for warming:Reference period = 1990-2002 return period = 46000 yr.However: large uncertainty90% confidence interval: = 9000 yr.
Literaturseminar 30. April, 2004
Modeling Regional climate model driven by two
general circulation models at the lateral boundaries.
Fairly high resolution
Model control period (CRTL) 1961-90 shows good agreement with measured data for northern Switzerland:T(CRTL) = 16.1°C , SD = 0.96°CT(Meas) = 16.9°C , SD = 0.94°C
Literaturseminar 30. April, 2004
Modeling: Future scenario (SCEN) 2071-2100 summer
Statistical temperature distributions resulting from the RCM driven by a greenhouse-gas scenario
Literaturseminar 30. April, 2004
Temperature change and variability according to SCEN
Literaturseminar 30. April, 2004
Temperature and precipitation anomalies in n. Switzerland
Measurement data 1864-2003 CTRL & SCEN data
Literaturseminar 30. April, 2004
Schär et al: Conclusion A shift of the statistical temperature
distribution towards warmer temperatures fails to explain summer 2003 temperatures
Proposal: An increase in variability as well as mean temperature may account for summer 2003 conditions
RCM simulations seem to verify this hypothesis