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Overview of climate change scenarios from Regional Climate Models (RCMs) - Northeastern North America, Arctic, NW Atlantic. Will Perrie BIO. 1) Climate change scenarios. IPCC-2007. Atmosphere-Ocean General Circulation Models (AOGCMs).
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Overview of climate change scenarios from Regional Climate Models (RCMs) - Northeastern North America, Arctic, NW Atlantic Will Perrie BIO
1) Climate change scenarios IPCC-2007 • Atmosphere-Ocean General Circulation Models (AOGCMs) • forced by concentrations of greenhouse gases + other constituents derived from various emissions scenarios • scenarios range from non-mitigation to idealized long-term scenarios. • A1: rapid economic growth, fossil / non-fossil energy • A1B: “ “ “, balance in energy source • A2: regionally oriented economic development • B1: global environmental sustainability • B2: local environmental sustainability
Sea ice anomalies Multi-model sea ice anomalies for 20th and 21th centuries for N Hemisphere January – March (JFM) and July-Sept. (JAS) for A2, A1B B1 scenarios
Composite AOGCM outputs Chapman+Walsh 2007 J Climate
Area averaged model – observations RMS errors for Arctic 70o -90o ocean
2) RCMs – Regional Climate Models • North American Regional Climate Change Assessment Program (NARCCAP) • to get high resolution climate change simulations to investigate regional scale future climate / scenarios • set of regional climate models (RCMs) driven by a set of atmosphere-ocean general circulation models (AOGCMs) • forcing by SRES A2 emissions scenarios for 21st century
CRCM simulations at BIO JULY Ground Mask (cgcm3.1(T47) , CRCM3.7.1)
CRCM simulations at BIO NARR- N America Reg. Re-analysis CGCM3.1(T47) CRCM3.7.1 January 2m Air temperature
CRCM simulations at BIO NARR CGCM3.1(T47) CRCM3.7.1 July 2m air temperature
Station time series comparisons -- observations -- CRCM -- CGCM3
Climate change impact on storm tracks Current climate 1975-1994 Future scenario 2040-2059 IPCC IS92a scenario Jiang and Perrie, 2007, J Climate
Summary notes… • Ensembles needed for climate models • ensembles can be collection of models, or single model systems with differing initializations • ensembles can simulate present climate • High variability in individual ensemble members • Future scenarios will require use of ensembles • inability of large ensembles to simulate sudden change • limitations due to assumptions in scenarios • Regional climate • advantage is high resolution • can accurately simulate present climate • need multi-member multi-decadal ensembles • completed initial simulations of ocean basin and shelf areas