Klimaendringer på Svalbard

Transkript

1 Klimaendringer på Svalbard Eirik J. Førland, met.no NGFs Geilo-Symposium, sept-2011

2 Tidlig forskningsaktivitet på Svalbard Vitenskapelige ekspedisjoner i det 16de og 17de århundret;- med bl.a.lufttrykks-målinger i midten av det 17de århundret Overvintring i det internasjonale Polar Året 1882/83 Kapp Thordsen, svenskehuset Målinger utført av norske fangstfolk i perioden i perioden De ble utstyrt med instrumenter fra Meteorologisk Institutt

3 Overvintrende fangstfolk utstyrt med instrumenter fra Meteorologisk Institutt

4 The first regular meteorological measurement site at Svalbard: Finneset in Grønfjorden Finneset at Grønfjorden, Svalbard Radio ca The station was in operation from december 1911 Picture from NPI

5 Meteorologiske stasjoner i Svalbard-regionen Stnr Navn I drift fra Hoh (m) TX BJØRNØYA , HOPEN , EDGEØYA - KAPP HEUGLIN , SVARTTANGEN , KONGSØYA , SØRKAPPØYA , HORNSUND , SVEAGRUVA , AKSELØYA (1898) 6 13, SVALBARD LUFTHAVN , NY-ÅLESUND , VERLEGENHUKEN , Isfjord Radio Barentsburg 1933-? Longyearbyen Ny-Ålesund-I xxxx Pyramiden 2011 xx

6 Temperatur ( C) Anual temperature at Svalbard Årsmiddel The temperature development during the first years of measurements at Svalbard might lead to dramatic conclusions

7 T, grader C Annual mean temperature ( o C) Svalbard Airp/Longyearbyen 2011 hittil Δ=+2.7C Årstemp~-3.9C : -3.7degC 2010: -4.1 degc o C/decade OBS filt 1 filt 2 Trend

8 Seasonal temperature ( o C) Svalbard Lufthavn-Longyearbyen Winter Summer (+0.25 o C/dec) Spring o C/dec o C/dec Autunm o C/dec

9 T, Deg. C Annual mean temperature, Arctic stations Ny-Ålesund Svalb-Airp/L Bar Isfjord-R Hopen Bjørnøya Jan Mayen

10 Linear temperature trends, o C per decade, sign. 5% level: bold Location Annual Winter Spring Summer Autumn Ny-Ålesund Svalbard A Hopen Bjørnøya Location Annual Winter Spring Summer Autumn Svalbard A Hopen Bjørnøya Ny-Ålesund Svalbard A Hopen Bjørnøya

11 Permafrost measurements, Janssonhaugen, Svalbard From K.Isaksen, met.no Permafrost and Climate in Europe (PACE)

12 Seasonal ground temperatures Janssonhaugen, Svalbard

13 Time series at different depths 25 m depth T C 30 m depth T C T C 40 m depth

14 Relation with air temperature Mean monthly ground temperature (0.2 m depth) vs. mean monthly air temperature (2 m screen height)

15 Conclusions, Permafrost In all boreholes there is a close relation between air, ground surface and ground temperatures, resulting in a preserved climate signal that penetrates into the permafrost. Significant warming is detectable down to at least 60 m depth. Calculated present decadal warming rates at the permafrost table are in the order of C/decade, with greatest warming in Svalbard and northern Sweden. The present trend shows accelerated warming during the latest decade. In future, a greater frequency of high-temperature anomalies, superimposed on a warming trend, may cause great irregular acceleration in near-surface permafrost thawing. Outliers like the 2005/2006 give us a indication into the types of anomalies we expect to become more common in Svalbard within the coming decades. (Permafrost info from ketil.isaksen@met.no)

16 Annual precipitation, Svalbard Airport - Longyearbyen :152 mm 2010:187 mm (2011: 99%) OBS filt 1 filt %/decade

17 mm Annual precipitation, Arctic stations Ny-Ålesund Svalbard Airport Isfjord Radio Bjørnøya Jan Mayen Hopen

18 Precipitation trends % per decade Station Period År Vinter Vår Sommer Høst Svalbard Airport ,2-1,0 2,0 4,5 3,2 Isfjord Radio ,0 11,2 8,4 8,5 9,6 Ny-Ålesund ,3 7,8-1,9-4,0 8,5 Hopen ,6 7,1 7,2 2,9 1,3 Bjørnøya ,1 4,4 5,0 0,9 2,7 Jan Mayen

19 Undercatch in precipitation gauges

20 Correction factor Undercatch, Norwegian precipitation gauge Undercatch, Norwegian gauge Wind speed (m/s) i=0.1 mm/h i=1 mm/h i=10 mm/h T=0 degc T= -5degC T= -10degC

21 Fraction (%) Fraction (%) Fraction (%) Annual fractions of liquid, solid and mixed precipitation at Svalbard Airport Liquid Solid Mixed

22 NorACIA: REGIONAL CLIMATE MODEL FOR NORDIC ARCTIC Regional climate model based upon HIRHAM version II (RegClim p.t. HIRHAM-I) Spatial resolution at the surface: ca. 24x24 km (HIRHAM-I: 55x55 km) Vertical resolution: 31 levels (HIRHAM-I: 19 levels) Other improvements compared to HIRHAM-I: New scheme for integration in time new scheme for forcings in the boundary layer Improved description of processes for modeling soil temperature and soil moisture Improved snow model (better description of albedo over snow covered ice)

23 NorACIA RCM simulations Spatial resolution 24x24 km, RCM: HIRHAM-II, AOGCM: MPI Time slices: and (SRES Emission scenario IS92a) and (SRES Emission scenario B2) EXAMPLES OF AVAILABLE NorACIA CLIMATE PROJECTIONS AVERAGE MEAN 2m TEMPERATURE (ANNUAL & SEASONAL) PRECIPITATION SUM (ANNUAL & SEASONAL) EXTREME 1-DAY RAINFALL (95 & 99 percentiles) EXTREME 1-DAY RAINFALL (5 year return period) 1-DAY RAINFALL > 20 MM SNOWFALL > 10 CM/DAY EXTREME WIND SPEED (95 & 99 percentiles) EXTREME WIND SPEED (5 year return period) Experimental: 1-h rainfall, 0 C shifts,

24 Projected change (degc) in temperature from to (Global model: MPI ECHAM4, SRES: B2; RCM: NorACIA 24 km)

25 Projected change (%) in precipitation from to (Global model: MPI ECHAM4 SRES: B2; RCM: NorACIA 24 km)

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27 Projiserte endringer i lufttemperatur (ºC) fra til (CMIP3 og SRES:A1b. Ensemblestørrelse: ~50 GCM s) Svalbard lufthavn / Longyearbyen År Vinter Vår Sommer Høst L (10%) 4,8 7,5 6,0 1,6 6,1 M (50%) 6,8 9,4 7,6 2,5 7,3 H (90%) 8,1 10,8 9,1 3,6 9,1 Bjørnøya År Vinter Vår Sommer Høst L (10%) 5,2 7,8 6,7 2,5 4,7 M (50%) 6,2 7,8 7,6 3,9 5,2 H (90%) 8,5 11,8 9,4 5,6 6,7

28 CONCLUSIONS NorACIA Projections (110 yrs) Temperature: Annual: Increase ca +3 C in SW, ca. +8 C in NE Seasonal: Smallest warming during summer, largest autumn and winter. Autumn and winter >+8 C in NE parts. Summer: Most parts +2->4 C. Barents Sea: Substantial increase in air temperatures for the ocean areas between Svalbard and Novaja Zemlja; particularly during September-May. Largest increase in areas where sea ice is replaced by open sea. Precipitation Annual: Svalbard increase 10-40%. Smallest increase in S and SW, largest increase in N and NE. Seasonal: Increase for all seasons. Largest increase autumn and winter Extremes: Substantial increase in number of events with heavy rainfall

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