Beijing, April 2002 Tianjun Mats Odd Helge Yongqi Tore HuiJun Helge Dabang

Journal of Geophysical Research, 49 citations

Journal of Geophysical Research, 40 citations

Annual mean surface temperature, mid Pliocene vs present (vegetation+ice sheet/sea ice+SST) The simulated differences of annual mean surface temperature between the middle Pliocene and the present (Exp2 minus Exp1, unit: °C). Areas with confidence level smaller than 99% are shaded.

Annual mean surface temperature, mid Pliocene vs present (SST and sea ice extent, only) The simulated differences of annual mean surface temperature induced by the reconstructed SST and sea ice extent (Exp2 minus Exp5, unit: °C). Areas with confidence level smaller than 99% are shaded.

Journal of Climate, 111 citations (part of the EU-project Dynamite)

Contour lines for 5870 m height of the 500-hPa geopotential, summer (reanalysis) Fig. 1. Contour lines for 5870 gpm of 500-hPa geopotential height for each summer during (a), (c) 1980–99 and (b), (d) 1958–79 from (a), (b) NCEP reanalysis and (c), (d) ERA-40. The thick contour line shows the mean for each time period.

Characteristic WPSH isolines at 500 hPa for IWP warming (red), cooling (blue) and control integration (black) Fig. 4. (b)–(f) The positions of characteristic WPSH (West Pacific Subtropical High) isoline at 500 hPa in IWP (Indian Ocean–western Pacific) warming (red) and cooling (blue) experiments and control runs (long-dashed black line) in the five AGCMs. The name of AGCM is marked at the left corner. (a) The model results are for a 30-yr mean. IAP refers to the GAMIL model. The condition of the NCEP reanalysis is shown [1980–99 (red line), 1958–79 (blue line), and 1958–99 (long-dashed black line) mean].

Journal of Climate

Atmospheric Bridge and Oceanic Tunnel ABOT Hadley Cell EQ SP NP Shallow subtropical cell Deep overturning circulation Ocean

Experiment 1 ABOT Atmosphere SP 30S EQ 30N NP Ocean Atmospheric Bridge + Oceanic Tunnel Atmosphere Coupled SP 30S EQ 30N NP Run 1 – CTRL Ocean

Experiment 1 ABOT Atmosphere SP 30S EQ 30N NP Ocean Atmospheric Bridge + Oceanic Tunnel Atmosphere Fixed Coupled Fixed SP 30S EQ 30N NP Run 1 – CTRL Ocean Run 2 – ABOT CTRL

Experiment 1 ABOT Atmosphere SP 30S EQ 30N NP Ocean Atmospheric Bridge + Oceanic Tunnel Atmosphere 2C SSTA 2C SSTA Fixed Coupled Fixed SP 30S EQ 30N NP Run 1 – CTRL Ocean Run 2 – ABOT CTRL

Experiment 1 ABOT Atmosphere SP 30S EQ 30N NP Ocean Atmospheric Bridge + Oceanic Tunnel Atmosphere 2C SSTA 2C SSTA Fixed Coupled Fixed SP 30S EQ 30N NP Run 1 – CTRL Ocean Run 2 – ABOT CTRL Run 3 – ABOT

Experiment 2 T-ABOT Tropical Atmospheric Bridge + Oceanic Tunnel Atmosphere 2C SSTA Coupled Fixed Coupled SP 30S EQ 30N NP Ocean

Experiment 3 OT Oceanic Tunnel only Atmosphere SP 30S EQ 30N NP Fixed Coupled Fixed SP 30S EQ 30N NP 2C SSTA 2C SSTA Ocean

Bergen Climate Model v1 OASIS ARPEGE/IFS spectral model Horizontal：TL63（2.8°） Vertical：31 levels,10 hPa Furevik et al., Clim. Dyn. 2003 Otterå et al., GRL 2003 Bentsen et al., Clim. Dyn. 2004 Frankignoul et al., Clim. Dyn. 2004 Otterå et al., Tellus 2004 Collins et al., J. Clim. 2005 Drange et al., AGU Monogr. 2005 Furevik and Nilsen, AGU Monogr. 2005 Kuzmina et al., GRL 2005 Minot and Frankignoul, Clim. Dyn. 2004 Sorteberg et al., GRL 2005 Sorteberg et al., AGU Monogr. 2005 Bergen Climate Model v1 OASIS MICOM (sea-ice ） Horizontal: 2.4°× 2.4° Vertical：24 layers，s0=23.54-28.10

Masks used for partial coupling

Global Response

SST-response ABOT

SST response OT

SST response T-ABOT

Temporal Response

ABOT

ABOT

T-ABOT

T-ABOT

OT

OT

Findings The simulated SST and sub-surface T responses are 1-1.5°C of the imposed SST-anomaly of 2°C Tropics vs Extratropics SST in the extratropics  SST in the tropics SST in the tropics  50% SST in the N+S extratropics 70% SST in the N extratropics 40% SST in the S extratropics Importance of AB and OT on SST: Atmos. Bridge 70% Ocean Tunnel 30% Importance of AB and OT on sub-surface T: Atmos. Bridge 10% Ocean Tunnel 90%

Bergen Climate Model Helge Drange1,2,3,4 with contributions from Asgeir Sorteberg2,3, Tore Furevik2,3, Tianjun Zhou4, Nils Gunnar Kvamstø2,3, Mats Bentsen1,3, Dabang Jiang4, Odd Helge Otterå1, Yongqi Gao1,4, Ina K. T. Kindem2,3 and the rest of the BCM group 1Nansen Environmental and Remote Sensing Center 2Geophysical Institute, University of Bergen 3Bjerknes Centre, UoB 4Institute of Atmospheric Physics/CAS

Bergen Climate Model Atmospheric model (ARPEGE/IFS) Coupler (OASIS) Ocean model (MICOM)

Performed integrations 300 yrs control simulation with present day value of atmospheric pCO2 and aerosol particles 4 x (2xCO2) CMIP-2 integrations (+1% CO2 ppm/yr for 80 yrs) 1 x 10xCO2 integration (+1% CO2 ppm/yr for 265 yrs) 1 x 150 yrs fresh-water integration (artificially increased fresh-water into the Arctic region)

Climate Change over China

Seasonal estimates of temperature in control simulation. Averages over Central China Central China: Mean of gridsquares inside the square from 100 to 120E and 28 to 42N (BCM: 35 gridsquares) OBS: NCEP reanalysis Data from 1950-1989 BCM: Averages over all 300 yrs Seasonal mean temperature estimates in BCM control integration and observational estimates from the NCEP renanlysis. Unit: C

Annual change in temperature after CO2 doubling CONTROL: E75 CMIP2 1% INCREASE: E76 CMIP2-CONTROL This is the annual changes in temperature around doubling of CO2 (year 70). Data are time averages between CMIP2 model year 60 and 80. (BCM year 2185-2204).

Seasonal changes in temperature after CO2 doubling. Averages over Central China Central China: Mean of gridsquares inside the square from 100 to 120E and 28 to 42N (35 gridsquares) This is the changes (CMIP2-CONTROL) in 2m temperature around doubling of CO2 (year 70). Data are time averages between CMIP2 model year 60 and 80. (BCM year 2185-2204). Seasonal mean difference in temperature after CO2 doubling (mean over year 60-80) compared to the control integration. Area: central China (area between 100-120E and 28-42N). Unit: C

Seasonal estimates of precipitation in control simulation. Averages over Central China Central China: Mean of gridsquares inside the square from 100 to 120E and 28 to 42N (BCM: 35 gridsquares) OBS: Global Precipitation Climatology Project (GPCP) Version: 2 Data from 1980-1999 BCM: Averages over all 300 yrs Seasonal mean precipitation estimates in BCM control integration and observational estimates from the GPCP V2 dataset. Unit: mm/day

Annual change in precipitation after CO2 doubling CONTROL: E75 CMIP2 1% INCREASE: E76 CMIP2-CONTROL This is the annual relative changes (%) in precipitation around doubling of CO2 (year 70). Data are time averages between CMIP2 model year 60 and 80. (BCM year 2185-2204). Annual mean relative difference in precipitation after CO2 doubling (mean over year 60-80). Unit: %

Seasonal changes in precipitation after CO2 doubling. Averages over Central China Central China: Mean of gridsquares inside the square from 100 to 120E and 28 to 42N (35 gridsquares) This is the relative changes ((CMIP2-CONTROL) /CONTROL) in precipitation around doubling of CO2 (year 70). Data are time averages between CMIP2 model year 60 and 80. (BCM year 2175-2004). Seasonal mean relative difference in precipitation after CO2 doubling (mean over year 60-80) compared to the control integration. Area: central China (area between 100-120E and 28-42N). Unit: %

Annual total runoff and changes after CO2 doubling CONTROL: E75 CMIP2 1% INCREASE: E76 TOTAL RUNOFF: This is just the exess water in the soil after soil saturation (so it is the water that potentially may run off). The saturation is determined by a saturation point dependent on the type of soil in the gridsquare. This is the annual mean (CONTROL) and changes (CMIP2-CONTROL) in total runoff around doubling of CO2 (year 70). Data are time averages between CMIP2 model year 60 and 80. (BCM year 2185-2204). Annual mean total runoff (left) and difference in total runoff (right) after CO2 doubling (mean over year 60-80) compared to the control integration. Unit: mm/day

Seasonal changes in total runoff after CO2 doubling. Averages over Central China Difference Relative difference Central China: Mean of gridsquares inside the square from 100 to 120E and 28 to 42N (35 gridsquares) This is the changes (CMIP2-CONTROL) and relative changes ((CMIP2-CONTROL) /CONTROL) in total runoff around doubling of CO2 (year 70). Data are time averages between CMIP2 model year 60 and 80. (BCM year 2175-2004). TOTAL RUNOFF: This is just the exess water in the soil after soil saturation (so it is the water that potentially may run off). The saturation is determined by a saturation point dependent on the type of soil in the gridsquare. Seasonal mean differences and relative differences in total runoff after CO2 doubling (mean over year 60-80) compared to the control integration. Area: central China (area between 100-120E and 28-42N). Unit: mm/day and %