alexander walther
DESCRIPTION
Alexander Walther. Physical Geographer Ph.D. student climatology. Acknowl. supervisors: Prof. Deliang Chen, Hans Linderholm. Research topics. Climate extremes (Temperature and precipitation) in past / present / future links to atmospheric circulation - PowerPoint PPT PresentationTRANSCRIPT
Regional Climate Group 2http://rc
g.gvc.gu.se
Department of Earth Sciences
Alexander WaltherPhysical GeographerPh.D. studentclimatology
Acknowl. supervisors:Prof. Deliang Chen, Hans Linderholm
Regional Climate Group 3http://rc
g.gvc.gu.se
Department of Earth Sciences
Research topics
Climate extremes (Temperature and
precipitation) in past/present/future
links to atmospheric circulation
the role played by anthropogenic
forcings
Sweden and Europe
Regional Climate Group 4http://rc
g.gvc.gu.se
Department of Earth Sciences
Observations ...
- precipitation- temperatures- daily- hourly- point
measurements with some spatial autocorrelation
... and models- precipitation- temperatures- ...- daily, hourly, 10-
min?- grid averages
Regional Climate Group 5http://rc
g.gvc.gu.se
Department of Earth Sciences
Diurnal variation in precipitation amount and frequency in SwedenCurrent work
Precipitation data in a mountainous catchment in Honduras: quality assessment and spatiotemporal characteristicsWesterberg et al. (accepted)
Thermal Growing Season (GSL)Walther & Linderholm (2006), Linderholm et al. (2008), Song et al. (2009)
Trend Atlas of EMULATE extremesChen et al. (2006)http://rcg.gvc.gu.se/data
Regional Climate Group 6http://rc
g.gvc.gu.se
Department of Earth Sciences
Diurnal variation in precipitation amount and frequency in Sweden
Regional Climate Group 7http://rc
g.gvc.gu.se
Department of Earth Sciences
observationsmodel
Regional Climate Group 8http://rc
g.gvc.gu.se
Department of Earth Sciences
Spatial scale of extreme precipitation
Regional Climate Group 9http://rc
g.gvc.gu.se
Department of Earth Sciences
GCM 44km 22km
min # of stations
Prec
1 5 1 5 1 5
40mm 0 0 21 81 55 100
25mm 1 5 27 90 70 98
10mm 7 14 56 91 85 99.9
5mm 22 34 74 97 93 100
2mm 45 58 86 99 96 100
Cases [%] where
interpolated rainfall
matches observed
rainfall
Regional Climate Group 10http://rc
g.gvc.gu.se
Department of Earth Sciences
Twentieth-century trends in the thermal growing season in the Greater Baltic Area
1901-1950 (=5>5F)
0o 10oE 20oE 30oE 40oE 50oE 52oN
56oN
60oN
64oN
68oN
72oN 1951-2000 (=5>5F)
0o 10oE 20oE 30oE 40oE 50oE 52oN
56oN
60oN
64oN
68oN
72oN 1901-2000 (=5>5F)
0o 10oE 20oE 30oE 40oE 50oE 52oN
56oN
60oN
64oN
68oN
72oN
1901-1950 (10d<5)
0o 10oE 20oE 30oE 40oE 50oE 52oN
56oN
60oN
64oN
68oN
72oN 1951-2000 (10d<5)
0o 10oE 20oE 30oE 40oE 50oE 52oN
56oN
60oN
64oN
68oN
72oN 1901-2000 (10d<5)
0o 10oE 20oE 30oE 40oE 50oE 52oN
56oN
60oN
64oN
68oN
72oN
1901-1950 (=5>5Fr|10d)
0o 10oE 20oE 30oE 40oE 50oE 52oN
56oN
60oN
64oN
68oN
72oN 1951-2000 (=5>5Fr|10d)
0o 10oE 20oE 30oE 40oE 50oE 52oN
56oN
60oN
64oN
68oN
72oN 1901-2000 (=5>5Fr|10d)
0o 10oE 20oE 30oE 40oE 50oE 52oN
56oN
60oN
64oN
68oN
72oN
Start
End
Length
GBA Average(1951-2000)
-6.3 days
+1.1 days
+7.4 days
Regional Climate Group 11http://rc
g.gvc.gu.se
Department of Earth Sciences
Trend atlas of the EMULATE indices (Chen et al., 2006)
http://rcg.gvc.gu.se
Regional Climate Group 12http://rc
g.gvc.gu.se
Department of Earth Sciences
TminTmax
Tmin/Tmax indices. Fraction of positive, positive significant, negative, and negative significant trends for 1901-2000. The areas showing the highest fractions for each index and season are colored.
pos pos* neg neg* pos pos* neg neg* pos pos* neg neg* pos pos* neg neg*MEANTN 84.2 61.4 15.8 1.8 91.2 68.4 8.8 3.5 93.0 66.7 7.0 0.0 87.7 35.1 12.3 0.0MEANTX 91.2 50.9 8.8 3.5 87.7 56.1 12.3 3.5 93.0 66.7 7.0 3.5 96.5 49.1 3.5 0.0TN2P 78.9 22.8 21.1 0.0 68.4 31.6 31.6 7.0 77.2 24.6 22.8 0.0 75.4 26.3 24.6 1.8TN5P 75.4 22.8 24.6 0.0 71.9 43.9 28.1 7.0 86.0 26.3 14.0 0.0 71.9 26.3 28.1 1.8TN10P 77.2 29.8 22.8 0.0 82.5 50.9 17.5 7.0 93.0 35.1 7.0 0.0 75.4 26.3 24.6 0.0TN90P 77.2 31.6 22.8 3.5 93.0 63.2 7.0 0.0 87.7 45.6 12.3 0.0 98.2 42.1 1.8 0.0TN95P 66.7 19.3 33.3 10.5 91.2 61.4 8.8 0.0 86.0 40.4 14.0 0.0 96.5 47.4 3.5 0.0TN98P 63.2 14.0 36.8 12.3 87.7 54.4 12.3 0.0 80.7 36.8 19.3 1.8 96.5 54.4 3.5 0.0TX2P 93.0 26.3 7.0 0.0 70.2 24.6 29.8 7.0 98.2 22.8 1.8 0.0 78.9 12.3 21.1 0.0TX5P 93.0 28.1 7.0 0.0 64.9 33.3 35.1 7.0 94.7 26.3 5.3 0.0 91.2 19.3 8.8 0.0TX10P 91.2 26.3 8.8 0.0 70.2 33.3 29.8 3.5 94.7 33.3 5.3 0.0 89.5 19.3 10.5 0.0TX90P 61.4 35.1 38.6 5.3 86.0 50.9 14.0 3.5 82.5 33.3 17.5 3.5 94.7 68.4 5.3 0.0TX95P 63.2 22.8 36.8 3.5 84.2 42.1 15.8 5.3 66.7 21.1 33.3 3.5 96.5 80.7 3.5 0.0TX98P 54.4 15.8 45.6 7.0 84.2 40.4 15.8 5.3 68.4 24.6 31.6 7.0 94.7 80.7 5.3 0.0TN2N 17.5 3.5 82.5 38.6 26.3 7.0 73.7 40.4 21.1 1.8 78.9 42.1 31.6 0.0 68.4 8.8TN5N 21.1 3.5 78.9 45.6 19.3 7.0 80.7 47.4 17.5 3.5 82.5 43.9 28.1 0.0 71.9 19.3TN10N 19.3 5.3 80.7 43.9 15.8 7.0 84.2 50.9 15.8 1.8 84.2 49.1 29.8 0.0 70.2 21.1TN90N 86.0 64.9 14.0 0.0 91.2 59.6 8.8 0.0 93.0 70.2 7.0 0.0 94.7 54.4 5.3 0.0TN95N 86.0 59.6 14.0 0.0 96.5 59.6 3.5 0.0 89.5 64.9 10.5 0.0 96.5 64.9 3.5 0.0TN98N 87.7 54.4 12.3 1.8 94.7 54.4 5.3 0.0 86.0 52.6 14.0 0.0 94.7 68.4 5.3 0.0TX2N 8.8 0.0 91.2 38.6 14.0 3.5 86.0 38.6 3.5 0.0 96.5 49.1 24.6 0.0 75.4 10.5TX5N 14.0 0.0 86.0 43.9 19.3 3.5 80.7 42.1 3.5 0.0 96.5 64.9 26.3 0.0 73.7 17.5TX10N 15.8 1.8 84.2 49.1 22.8 3.5 77.2 45.6 1.8 0.0 98.2 71.9 29.8 0.0 70.2 19.3TX90N 87.7 50.9 12.3 3.5 84.2 52.6 15.8 5.3 89.5 50.9 10.5 5.3 98.2 84.2 1.8 0.0TX95N 86.0 50.9 14.0 3.5 84.2 45.6 15.8 3.5 84.2 45.6 15.8 5.3 98.2 84.2 1.8 0.0TX98N 86.0 43.9 14.0 3.5 84.2 40.4 15.8 3.5 82.5 35.1 17.5 7.0 96.5 82.5 3.5 0.0HWDI 84.2 22.8 15.8 0.0 73.7 21.1 26.3 3.5 64.9 5.3 28.1 3.5 89.5 36.8 5.3 0.0WSDI90 82.5 24.6 17.5 0.0 75.4 24.6 24.6 3.5 73.7 14.0 26.3 3.5 96.5 49.1 3.5 0.0CSDI10 19.3 0.0 80.7 22.8 28.1 0.0 71.9 19.3 17.5 0.0 82.5 35.1 29.8 0.0 70.2 7.0FD 15.8 0.0 84.2 52.6 15.8 0.0 84.2 52.6 15.8 0.0 84.2 52.6 15.8 0.0 84.2 52.6
JJA SON DJF
Tm
in/T
max
MAM
+ - + - + - + -
perc
entil
esco
ldw
arm
cold
war
mco
ld
Regional Climate Group 13http://rc
g.gvc.gu.se
Department of Earth Sciences
Prec indices: Fraction of positive, positive significant, negative, and negative significant trends for 1901-2000. The areas showing the highest fractions for each index and season are colored.
pos pos* neg neg* pos pos* neg neg* pos pos* neg neg* pos pos* neg neg*PRECTOT 68.0 14.0 32.0 3.0 48.0 6.0 52.0 3.0 67.0 21.0 33.0 3.0 78.0 27.0 22.0 2.0PREC90P 65.0 7.0 35.0 4.0 50.0 5.0 50.0 4.0 68.0 19.0 32.0 1.0 76.0 26.0 24.0 4.0PREC95P 74.0 15.0 26.0 1.0 56.0 8.0 44.0 4.0 72.0 20.0 28.0 3.0 79.0 27.0 21.0 1.0PREC98P 80.0 7.0 20.0 2.0 60.0 9.0 40.0 4.0 66.0 19.0 34.0 3.0 72.0 20.0 28.0 2.0R90N 65.0 13.0 35.0 3.0 57.0 6.0 43.0 3.0 67.0 19.0 33.0 1.0 77.0 22.0 23.0 3.0R90T 68.0 11.0 32.0 1.0 68.0 12.0 32.0 2.0 68.0 21.0 32.0 2.0 70.0 28.0 30.0 3.0R90AM 71.0 15.0 29.0 3.0 55.0 9.0 45.0 3.0 68.0 22.0 32.0 3.0 78.0 33.0 22.0 3.0R95N 71.0 15.0 29.0 4.0 64.0 7.0 36.0 3.0 71.0 21.0 29.0 6.0 75.0 22.0 25.0 2.0R95T 72.0 10.0 28.0 0.0 68.0 14.0 32.0 2.0 66.0 15.0 34.0 3.0 73.0 19.0 27.0 2.0R95AM 74.0 14.0 26.0 2.0 62.0 11.0 38.0 3.0 70.0 22.0 30.0 5.0 77.0 31.0 23.0 2.0R98N 72.0 11.0 28.0 2.0 59.0 13.0 41.0 1.0 65.0 22.0 35.0 2.0 77.0 18.0 23.0 1.0R98T 75.0 5.0 25.0 1.0 67.0 14.0 33.0 1.0 68.0 18.0 32.0 1.0 71.0 17.0 29.0 4.0R98AM 72.0 10.0 28.0 2.0 61.0 12.0 39.0 3.0 68.0 21.0 32.0 4.0 79.0 21.0 21.0 2.0SDII90p 70.0 6.0 30.0 0.0 61.0 14.0 39.0 2.0 60.0 14.0 40.0 2.0 73.0 15.0 27.0 0.0SDII95p 63.0 6.0 37.0 1.0 57.0 10.0 43.0 0.0 66.0 8.0 34.0 1.0 70.0 7.0 30.0 2.0SDII98p 56.0 8.0 44.0 0.0 58.0 11.0 42.0 1.0 66.0 12.0 34.0 1.0 66.0 19.0 34.0 0.0SDII 77.0 19.0 23.0 3.0 63.0 14.0 37.0 4.0 66.0 24.0 34.0 5.0 77.0 38.0 23.0 2.0R5d 70.0 10.0 30.0 3.0 67.0 11.0 33.0 1.0 67.0 20.0 33.0 2.0 79.0 20.0 21.0 2.0R1d 65.0 11.0 35.0 0.0 59.0 8.0 41.0 0.0 67.0 13.0 33.0 1.0 73.0 21.0 27.0 3.0CDD 58.0 5.0 42.0 1.0 71.0 1.0 29.0 1.0 57.0 1.0 43.0 3.0 48.0 0.0 52.0 2.0
JJA SON DJF
pre
cip
ita
tio
n
MAM+ - + - + - + -
Regional Climate Group 14http://rc
g.gvc.gu.se
Department of Earth Sciences
Ongoing and planned
• atmospheric circulation mechanisms behind extreme precipitation events
• When does it rain and why• How will precipitation patterns (extremes,
diurnal cycle) evolve in the future• Do anthropogenic forcing plays a role
Regional Climate Group 15http://rc
g.gvc.gu.se
Department of Earth Sciences
Research topics
Climate extremes (Temperature and
precipitation) in past/present/future
links to atmospheric circulation
the role played by anthropogenic
forcings
Sweden and Europe