a glimpse on climate variability and change in...

Federal Departement of Home Affairs FDHA

Federal Office of Meteorology and Climatology MeteoSwiss

A glimpse on climate variability and change in Switzerland

Simon Scherrer Climate division, MeteoSwiss

2 ASG Rhine - Snow & Glacier Workshop ¦ 26 Nov 2015

Simon Scherrer, MeteoSwiss

Contents

(1) observed

climate variability & trends temperature

precipitation

snow

fog

sunshine

Extremes?

(2) future climate change temperature

precipitation

snow

Extremes?

(3) Climate Services: National Centre for Climate Services (NCCS)

http://www.google.ch/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http://someinterestingfacts.net/why-does-rain-fall-in-drops/rain-drops-on-a-window/&ei=_OLlVOq9E8uqPLCvgKgK&bvm=bv.85970519,d.ZWU&psig=AFQjCNGtya6n2QwbQDRWWYA6JpRrQ-rhUQ&ust=1424438353466948

http://www.google.ch/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http://www.sturmforum.ch/viewtopic.php?f%3D2%26t%3D9070&ei=N-TlVLX-D83bPafSgLAC&bvm=bv.85970519,d.ZWU&psig=AFQjCNHaSajE1TWaCSupxUyUMjA1dmyxPQ&ust=1424438672084187

http://www.google.ch/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http://someinterestingfacts.net/why-does-rain-fall-in-drops/rain-drops-on-a-window/&ei=_OLlVOq9E8uqPLCvgKgK&bvm=bv.85970519,d.ZWU&psig=AFQjCNGtya6n2QwbQDRWWYA6JpRrQ-rhUQ&ust=1424438353466948

http://www.google.ch/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http://www.sturmforum.ch/viewtopic.php?f%3D2%26t%3D9070&ei=N-TlVLX-D83bPafSgLAC&bvm=bv.85970519,d.ZWU&psig=AFQjCNHaSajE1TWaCSupxUyUMjA1dmyxPQ&ust=1424438672084187



Temperature…



global (HadCRUT4)

Temperature change CH & global time series, changes 1864-2014 and outlook 2015 [°C]

Switzerland

CH:global = 2.3:1

cold 1880s

warm late1940s

warm last 30 years

tem

pe

ratu

re a

no

ma

ly [

°C]

wrt

mean

18

64

-19

00

2°C target:

half way reached!

http://www.google.ch/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http://www.lincolnfp.com/minisite/about/globalcapabilities&ei=DzPrVIvZBsHXPMGTgaAP&bvm=bv.86475890,d.d24&psig=AFQjCNHRaBTVlwlOUhFkiyZhz-xXWrWd2A&ust=1424786563605239

http://s1.1zoom.me/big3/339/338457-Berserker.jpg



Temperature change Switzerland deviations from norm 1961-1990 (°C) (1961-2014; 2015: 1.1.-31.10.)

2015 Jan-Oct

Rank 4



0°C-line 1961-2015

150-200m increase per °C warming

winter: +325m (600 825m)

(+60m/10J)

autumn: +200m (2325 2525m)

(+38m/10J)

(+74m/10J)

spring: +400m (1750 2150m)

(+72m/10J)

summer: +375m (3200 3575m

http://www.google.ch/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http://www.dreamstime.com/stock-images-collection-four-rounded-seasons-icons-daisy-flower-spring-sun-summer-leaf-autumn-snowflake-winter-image29773124&ei=YljjVKPSAYjEPMXFgNAE&bvm=bv.85970519,d.d2s&psig=AFQjCNHBMqA1dvwSXXhzACy9gq6_UaYeLA&ust=1424271797101905






Frost days 1959-2014 station abs.Trend rel.Trend

[ind] [u/10yrs] [%]

BER -4.80 -24.7

SIO -1.75 -10.3

DAV -5.36 -15.4

LUG -4.48 -82.4



Summer days 1959-2015

station abs.Trend rel.Trend

[ind] [d/10yrs] [%]

BER 3.85 61.6

SIO 5.85 53.2

DAV 2.10 398.6

LUG 6.54 63.4



Hot temperature extremes (1) «Intensities» Swiss mean from 9 stations [°C], 1901-2015

hottest day

hottest week

annual mean

an

om

aly

[°C

]

wrt

1901

-20

14 p

erio

d



Hot temperature extremes (2) «Frequency» Swiss mean from 9 stations [°C], 1901-2015

nu

mb

er

of

days

exce

ed

ing

90

th, 9

5th, 9

9th p

erc

en

tile

in

JJA

doubling (or more) for

95th, 99th percentile events



precipitation…



2015: a dry year on the Plateau? Bern / Zollikofen

very

dry

large

range

possible!



Mean annual precipitation 1971-2008

Isotta et al. (2013)

boundaries

Rhine catchment

[mm]



Revisiting annual precipitation trends

Southern Alps

Northern &

Central Alps

Plateau &

Jura

Scherrer et al. (IntJClim, 2016)

+ 5-30%/100yrs

sign. (p<0.05)



Winter- & summer trends

+

−

5-40%/100yrs

-4-5%/10yrs

Winter (DJF) Summer (JJA)

+

sign. (p<0.05)

Scherrer et al. (IntJClim, 2016)





Changes heavy daily precipitation Intensity and frequency, 1901-2014 (annual)

max.

daily sum

per year

(Rx1day)

# q99

events

per year

91% show pos. trend

92% show

pos. trend

Scherrer et al. (JGR, in revision)

intensity

frequency



D. Gerstgrasser

snow…



Days with snow pack measurement data (bold) and reconstruction (thin lines)

Scherrer et al. (2013)



Trends: Days with snow pack relative 20-yr running trends [% / 10J], bold: sign. 5% level

altitude [

m ü

M]

recovery

500

1000

1500

2000

strongest

decreases

pure reconstruction




Internet

sunshine duration…



Sunshine duration Switzerland Deviations (% from norm 1961-1990) (1961-2014)



Sunshine duration high altitude: Jungfraujoch

sunshin

e d

ura

tion (

h)

Year: ±0h / ±0% (no dimming/brightening)



Sunshine duration Swiss Plateau: Bern

sunshin

e d

ura

tion (

h)

Year: +200h / +12%

DJF: +42h / +22% (p=0.03) MAM: +79h / +17% (p=0.07)

JJA: +35h / +5% (p=0.33) SON: +23h / +6% (p=0.52)

«Dimming»

«Brightening»



Sunshine duration 1884-2014 Zürich/Fluntern, ratio wrt. norm 1961-1990

(courtesy of M. Begert)

1961-2014

today’s level similar to end of 19th century



D. Gill

(High) fog…



Reconstructed fog series 1902-2012 Zürich/Fluntern, September − March


green: classical fog observation (horiz. visibility <1km)

blue: fog (more than half a day)

rot: fog (full day)

black: fog days (more than half a day) with fog dispersal

num

ber

of

days



«High fog» changes «half day fog» 1991-2009 vs. 1961-1990

+17% +1%

-13%

-38% -28%

-25% -37%

strong declines in March and autumn




Climate change Europe 2070-2099 (A1B)

Source: Swiss Climate

Change Scenarios CH2011

1.0

1.5

2.0

2.5

3.0

3.5

4.0

°C

-36

-28

-20

-12

-4

4

12

20

28

36

%



Less frost days?



Frost days (Tmin ≤ 0°C)

mean number of frost days per year [days]

today

(1980-2009)

A1B-Scenario

~2035

A1B-Scenario

~2060

A1B-Scenario

~2085

Strong decline of the number

of frost days until end of century

Increased glacier and

snow melt



No snow on Swiss Plateau?



Changes in days with fresh snow Zubler et al. 2013

today

(1980-2009) A1B-Scenario

~2035

A1B-Scenario

~2060

A1B-Scenario

~2085

mean number of days with fresh

snow per year

relative change

Loss of days with fresh snow by

50-80% on the Swiss Plateau &

foothills of the Alps, loss by 20-

30% in the Alps



A longer growing season?

http://www.google.ch/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=UN96EpSa01RsAM&tbnid=T57e2xR6jzwLAM:&ved=0CAUQjRw&url=http://mx.ibtimes.com/articles/27324/20120830/donacion-banco-mundial-mexico-sustentabilidad-biodiversidad.htm&ei=rHPmUpuAJ6WX0AWLlYHYBw&psig=AFQjCNHecTAyKvtUHqiXqi1pUjM70AE9Rw&ust=1390920914913264



today

(1980-2009)

A1B-Scenario

~2035

A1B-Scenario

~2060

Duration of growing season

Mean duration of growing season [days]

Unter A1B ist eine

Verlängerung der

Vegetationsperiode um

etwa 2 Monate möglich

A1B-Scenario

~2085

A lengthening of the growing season

by about two months is possible



More heat waves?



today

(1980-2009)

Tropical nights (Tmin ≥ 20°C)

mean number of tropical nights per year [days]

A1B-Scenario

~2035

A1B-Scenario

~2060

A1B-Scenario

~2085

Hot summer 2003:

7 tropical nights in Basel

around 2085 it could be 20-30

on average. Health risks!



today

The emission path taken is essential number of tropical nights

2085

today

no intervention strong reduction technical progress



National Centre for Climate Services gegründet am 16. November 2015

Das Netzwerk für

Klimadienstleistungen

des Bundes



Das NCCS… das Netzwerk für Klimadienstleistungen des Bundes

• koordiniert die Erarbeitung und Verbreitung von


• fördert als Schnittstelle zwischen den Produzenten und

Nutzern den Dialog und die gemeinsame Entwicklung der


• sorgt dafür, dass die Klimadienstleistungen auf die

Bedürfnisse der Nutzer ausgerichtet sind

• stellt Klimadienstleistungen in verständlicher Form zur

Verfügung

www.nccs.ch



Themenschwerpunkte

Klimaszenarien

Wasserkreislauf

Waldfunktionen

Schadorganismen

Gefahrenprozesse



• The Alpine climate is influenced by different air masses

(oceanic/continental air) and thus very variable by nature

• The Alpine climate has already changed (half way of 2°C

target reached) and will change due to climate change

• The amplitude of future change stronly depends on

decisions taken in the near future

• The new NCCS wants to facilitate the use of climate

information for research, applications and decision making

Summary

a glimpse on climate variability and change in...

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