Simulations of the Permian (251 Ma) Monsoon Using CCSM3 ... · Simulations of the Permian (251 Ma)...
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Simulations of the Permian (251 Ma) Monsoon Using CCSM3 Simulations of the Permian (251 Ma) Monsoon Using CCSM3 (Community Climate System Model, Version 3) (Community Climate System Model, Version 3) C.A. Shields and J.T. C.A. Shields and J.T. Kiehl Kiehl NCAR NCAR The nature of monsoons has been studied extensively in the scientific community because of its significance in dominating regional weather and climate and its impact on society. The nature of monsoons has been studied extensively in the scientific community because of its significance in dominating regional weather and climate and its impact on society. Analyzing the underlying mechanisms behind the monsoon for past climates gives us a deeper understanding of what drives the monsoon for today. In this study, we use the Community Analyzing the underlying mechanisms behind the monsoon for past climates gives us a deeper understanding of what drives the monsoon for today. In this study, we use the Community Climate System Model (CCSM3) to analyze the Permian (251 Ma) northern hemisphere monsoon. At the Permian-Triassic boundary (251Ma), Earth experienced its greatest mass Climate System Model (CCSM3) to analyze the Permian (251 Ma) northern hemisphere monsoon. At the Permian-Triassic boundary (251Ma), Earth experienced its greatest mass extinction of all time where 90-95% of ocean species and 70% of terrestrial life was lost (Erwin, 1993). Elevated levels of CO2, anoxic oceans, and intense volcanic activity are extinction of all time where 90-95% of ocean species and 70% of terrestrial life was lost (Erwin, 1993). Elevated levels of CO2, anoxic oceans, and intense volcanic activity are believed to have been major factors in this mass extinction event. Results from believed to have been major factors in this mass extinction event. Results from Kiehl Kiehl and Shields (2005) show the fully coupled model, CCSM3, support both the current extinction and Shields (2005) show the fully coupled model, CCSM3, support both the current extinction hypotheses and the available observational record. This poster presents further work built upon the KS2005 modeling study but as relevant to monsoons. hypotheses and the available observational record. This poster presents further work built upon the KS2005 modeling study but as relevant to monsoons. We find that the We find that the fundamental mechanism driving the northern hemisphere Permian monsoon is the location of the sea surface temperature (SST) warm pool and not the fundamental mechanism driving the northern hemisphere Permian monsoon is the location of the sea surface temperature (SST) warm pool and not the strength of land-sea temperature gradients. strength of land-sea temperature gradients. Motivation and Primary Conclusion Motivation and Primary Conclusion CCSM3, T31_gx3 Fully Coupled, Permian 10X CO2, NH Peninsula & Equatorial Islands Removed CCSM3, T31_gx3 Fully Coupled, Permian 10X CO2, NH Peninsula & Equatorial Islands Removed 10X No Island Coupled 0X No Island Coupled CAM3 T31 Stand-alone, Permian 10X CO CAM3 T31 Stand-alone, Permian 10X CO 2 , Northern Hemisphere Peninsula Removed , Northern Hemisphere Peninsula Removed 10X No Peninsula CAM 10X No Peninsula CAM CAM3 T31 Stand-alone, 10X Present Day Values of CO CAM3 T31 Stand-alone, 10X Present Day Values of CO 2 10X Permian CAM 10X Permian CAM CCSM3, T31_gx3 Fully Coupled, Present Day Control CCSM3, T31_gx3 Fully Coupled, Present Day Control PD Coupled PD Coupled CCSM3, T31_gx3 Fully Coupled, 10X Present Day Values of CO CCSM3, T31_gx3 Fully Coupled, 10X Present Day Values of CO 2 (KS, 2005) (KS, 2005) 10X Permian Coupled 10X Permian Coupled Experiments Experiments References References Shields, C.A., Shields, C.A., Kiehl Kiehl, J.T., 2007, Model Simulations of the Permian (251 Ma) Monsoon Using the Community Climate System Model , J.T., 2007, Model Simulations of the Permian (251 Ma) Monsoon Using the Community Climate System Model (CCSM3), in prep. (CCSM3), in prep. Kiehl Kiehl, J.T., Shields, C.A., 2005, Climate Simulation of the Latest Permian: Implications for Mass Extinction, Geology, , J.T., Shields, C.A., 2005, Climate Simulation of the Latest Permian: Implications for Mass Extinction, Geology, vol vol 33, no9, p757- 33, no9, p757- 760. 760. Erwin, D.H., 1993, The great Paleozoic crisis, life and death in the Permian: New York, Columbia University Press, 327 p. Erwin, D.H., 1993, The great Paleozoic crisis, life and death in the Permian: New York, Columbia University Press, 327 p. Meehl Meehl, G.A., , G.A., Arblaster Arblaster, J.M., Lawrence, D.M., , J.M., Lawrence, D.M., Seth,A Seth,A., ., Schneider,E.K Schneider,E.K., ., Kirtman,B.P Kirtman,B.P., ., Min,D Min,D., 2006, Monsoon Regimes in the CCSM3, ., 2006, Monsoon Regimes in the CCSM3, Journal of Climate, Journal of Climate, vol vol 19, no 11, p2482-2495. 19, no 11, p2482-2495. JJA surface temperatures JJA surface temperatures and precipitation for the and precipitation for the 10X Permian Coupled 10X Permian Coupled simulation. The warm pool simulation. The warm pool sits just south of the sits just south of the northern hemisphere northern hemisphere peninsula between 90 and peninsula between 90 and 180E. Monsoonal 180E. Monsoonal precipitation exists in the precipitation exists in the region just off the region just off the peninsula. peninsula. The seasonal cycle in The seasonal cycle in the 10X Permian the 10X Permian Coupled simulation Coupled simulation peaks in August, one peaks in August, one month shifted from month shifted from the PD Control and the PD Control and observations. The PD observations. The PD Control simulation Control simulation reasonably captures reasonably captures both spatial and both spatial and temporal temporal characteristics of the characteristics of the Indian Monsoon. Indian Monsoon. State of the Monsoon: 10X Permian and PD Coupled State of the Monsoon: 10X Permian and PD Coupled Testing Atmospheric Response to SST Warm Pool by Removing Land: 10X No Peninsula Testing Atmospheric Response to SST Warm Pool by Removing Land: 10X No Peninsula CAM CAM Testing Ocean Response by Allowing Migration of SST Warm Pool: 10X No Island Testing Ocean Response by Allowing Migration of SST Warm Pool: 10X No Island Coupled Coupled The figure to the left is JJA precipitation for The figure to the left is JJA precipitation for both the No Peninsula case as well as the both the No Peninsula case as well as the CAM3 Permian control. The monsoonal CAM3 Permian control. The monsoonal precipitation is clearly still present and in the precipitation is clearly still present and in the same approximate location despite the removal same approximate location despite the removal of the peninsula. This suggests that the land-sea of the peninsula. This suggests that the land-sea temperature gradients are not responsible for temperature gradients are not responsible for the precipitation maximum in the 90-150E and the precipitation maximum in the 90-150E and 9-21N monsoon zone 9-21N monsoon zone. The seasonal cycle for the atmospheric velocity potential is evaluated by The seasonal cycle for the atmospheric velocity potential is evaluated by comparing JJA-DJF for the 10X Permian Coupled run, the 10X Permian CAM and comparing JJA-DJF for the 10X Permian Coupled run, the 10X Permian CAM and the 10X Permian No Peninsula CAM. We are confident that the CAM stand-alone the 10X Permian No Peninsula CAM. We are confident that the CAM stand-alone runs accurately represent the atmospheric climate from the CCSM3. Note that the runs accurately represent the atmospheric climate from the CCSM3. Note that the CAM runs were forced by SST data from the coupled run. All three of the above CAM runs were forced by SST data from the coupled run. All three of the above plots show there is no significant difference between any of these simulations. This plots show there is no significant difference between any of these simulations. This again implies that the monsoonal dynamics are not impacted by the removal of again implies that the monsoonal dynamics are not impacted by the removal of land in this region. land in this region. SSTs for the 10X Permian Coupled and the 10X No Island Coupled on the far left top and middle SSTs for the 10X Permian Coupled and the 10X No Island Coupled on the far left top and middle panels show the migration and expansion of the warm pool. The precipitation differences can be panels show the migration and expansion of the warm pool. The precipitation differences can be seen on the bottom panel. Precipitation shifts westward (landward) with the expansion of the warm seen on the bottom panel. Precipitation shifts westward (landward) with the expansion of the warm pool. Interestingly, the removal of the equatorial islands not only allows the expansion of the pool. Interestingly, the removal of the equatorial islands not only allows the expansion of the warm pool, but also changes the nature of the convective zones along the ITCZ. The center panels warm pool, but also changes the nature of the convective zones along the ITCZ. The center panels show the seasonal cycle of the SST expansion. The warm pool moves significantly westward show the seasonal cycle of the SST expansion. The warm pool moves significantly westward (landward) from July through November with the maximum now in October. The seasonal cycle (landward) from July through November with the maximum now in October. The seasonal cycle of the precipitation on the far right panel illustrates once again the spatial and temporal shifts in of the precipitation on the far right panel illustrates once again the spatial and temporal shifts in peak precipitation. peak precipitation. The oceanic undercurrent is shown to the right. The oceanic undercurrent is shown to the right. When the equatorial islands are removed and When the equatorial islands are removed and ocean currents are allowed to flow freely in the ocean currents are allowed to flow freely in the Paleo-Teyths Paleo-Teyths Ocean, the undercurrent flattens and Ocean, the undercurrent flattens and extends westward (landward) to ~30E towards the extends westward (landward) to ~30E towards the Pangean Pangean coast. Increased coastal surface winds and coast. Increased coastal surface winds and ocean stresses directly lee of ocean stresses directly lee of Pangea Pangea from 30N to from 30N to 30S (not shown) prevent the undercurrent from 30S (not shown) prevent the undercurrent from reaching the coast. These surface stresses also reaching the coast. These surface stresses also serve to serve to advect advect cooler water cooler water equatorward equatorward and and prevent the SST warm pool from ultimately prevent the SST warm pool from ultimately reaching the coast as well. (Areas not contoured in reaching the coast as well. (Areas not contoured in the 10X Permian Coupled plot represent land the 10X Permian Coupled plot represent land areas, i.e. equatorial islands). areas, i.e. equatorial islands).
Transcript of Simulations of the Permian (251 Ma) Monsoon Using CCSM3 ... · Simulations of the Permian (251 Ma)...
Simulations of the Permian (251 Ma) Monsoon Using CCSM3Simulations of the Permian (251 Ma) Monsoon Using CCSM3(Community Climate System Model, Version 3)(Community Climate System Model, Version 3)
C.A. Shields and J.T. C.A. Shields and J.T. KiehlKiehl
NCARNCAR
The nature of monsoons has been studied extensively in the scientific community because of its significance in dominating regional weather and climate and its impact on society.The nature of monsoons has been studied extensively in the scientific community because of its significance in dominating regional weather and climate and its impact on society.Analyzing the underlying mechanisms behind the monsoon for past climates gives us a deeper understanding of what drives the monsoon for today. In this study, we use the CommunityAnalyzing the underlying mechanisms behind the monsoon for past climates gives us a deeper understanding of what drives the monsoon for today. In this study, we use the CommunityClimate System Model (CCSM3) to analyze the Permian (251 Ma) northern hemisphere monsoon. At the Permian-Triassic boundary (251Ma), Earth experienced its greatest massClimate System Model (CCSM3) to analyze the Permian (251 Ma) northern hemisphere monsoon. At the Permian-Triassic boundary (251Ma), Earth experienced its greatest massextinction of all time where 90-95% of ocean species and 70% of terrestrial life was lost (Erwin, 1993). Elevated levels of CO2, anoxic oceans, and intense volcanic activity areextinction of all time where 90-95% of ocean species and 70% of terrestrial life was lost (Erwin, 1993). Elevated levels of CO2, anoxic oceans, and intense volcanic activity arebelieved to have been major factors in this mass extinction event. Results from believed to have been major factors in this mass extinction event. Results from KiehlKiehl and Shields (2005) show the fully coupled model, CCSM3, support both the current extinction and Shields (2005) show the fully coupled model, CCSM3, support both the current extinctionhypotheses and the available observational record. This poster presents further work built upon the KS2005 modeling study but as relevant to monsoons. hypotheses and the available observational record. This poster presents further work built upon the KS2005 modeling study but as relevant to monsoons. We find that theWe find that thefundamental mechanism driving the northern hemisphere Permian monsoon is the location of the sea surface temperature (SST) warm pool and not thefundamental mechanism driving the northern hemisphere Permian monsoon is the location of the sea surface temperature (SST) warm pool and not thestrength of land-sea temperature gradients.strength of land-sea temperature gradients.
Motivation and Primary ConclusionMotivation and Primary Conclusion
CCSM3, T31_gx3 Fully Coupled, Permian 10X CO2, NH Peninsula & Equatorial Islands RemovedCCSM3, T31_gx3 Fully Coupled, Permian 10X CO2, NH Peninsula & Equatorial Islands Removed110X No Island Coupled0X No Island Coupled
CAM3 T31 Stand-alone, Permian 10X COCAM3 T31 Stand-alone, Permian 10X CO22, Northern Hemisphere Peninsula Removed, Northern Hemisphere Peninsula Removed10X No Peninsula CAM10X No Peninsula CAM
CAM3 T31 Stand-alone, 10X Present Day Values of COCAM3 T31 Stand-alone, 10X Present Day Values of CO2210X Permian CAM10X Permian CAM
CCSM3, T31_gx3 Fully Coupled, Present Day ControlCCSM3, T31_gx3 Fully Coupled, Present Day ControlPD CoupledPD Coupled
CCSM3, T31_gx3 Fully Coupled, 10X Present Day Values of COCCSM3, T31_gx3 Fully Coupled, 10X Present Day Values of CO22 (KS, 2005) (KS, 2005)10X Permian Coupled10X Permian CoupledExperimentsExperiments
ReferencesReferences
Shields, C.A., Shields, C.A., KiehlKiehl, J.T., 2007, Model Simulations of the Permian (251 Ma) Monsoon Using the Community Climate System Model, J.T., 2007, Model Simulations of the Permian (251 Ma) Monsoon Using the Community Climate System Model(CCSM3), in prep.(CCSM3), in prep.
KiehlKiehl, J.T., Shields, C.A., 2005, Climate Simulation of the Latest Permian: Implications for Mass Extinction, Geology, , J.T., Shields, C.A., 2005, Climate Simulation of the Latest Permian: Implications for Mass Extinction, Geology, volvol 33, no9, p757- 33, no9, p757-760.760.
Erwin, D.H., 1993, The great Paleozoic crisis, life and death in the Permian: New York, Columbia University Press, 327 p.Erwin, D.H., 1993, The great Paleozoic crisis, life and death in the Permian: New York, Columbia University Press, 327 p.
MeehlMeehl, G.A., , G.A., ArblasterArblaster, J.M., Lawrence, D.M., , J.M., Lawrence, D.M., Seth,ASeth,A., ., Schneider,E.KSchneider,E.K., ., Kirtman,B.PKirtman,B.P., ., Min,DMin,D., 2006, Monsoon Regimes in the CCSM3,., 2006, Monsoon Regimes in the CCSM3,Journal of Climate, Journal of Climate, volvol 19, no 11, p2482-2495. 19, no 11, p2482-2495.
JJA surface temperaturesJJA surface temperaturesand precipitation for theand precipitation for the10X Permian Coupled10X Permian Coupledsimulation. The warm poolsimulation. The warm poolsits just south of thesits just south of thenorthern hemispherenorthern hemispherepeninsula between 90 andpeninsula between 90 and180E. Monsoonal180E. Monsoonalprecipitation exists in theprecipitation exists in theregion just off theregion just off thepeninsula.peninsula.
The seasonal cycle inThe seasonal cycle inthe 10X Permianthe 10X PermianCoupled simulationCoupled simulationpeaks in August, onepeaks in August, onemonth shifted frommonth shifted fromthe PD Control andthe PD Control andobservations. The PDobservations. The PDControl simulationControl simulationreasonably capturesreasonably capturesboth spatial andboth spatial andtemporaltemporalcharacteristics of thecharacteristics of theIndian Monsoon.Indian Monsoon.
State of the Monsoon: 10X Permian and PD CoupledState of the Monsoon: 10X Permian and PD Coupled
Testing Atmospheric Response to SST Warm Pool by Removing Land: 10X No PeninsulaTesting Atmospheric Response to SST Warm Pool by Removing Land: 10X No PeninsulaCAMCAM
Testing Ocean Response by Allowing Migration of SST Warm Pool: 10X No IslandTesting Ocean Response by Allowing Migration of SST Warm Pool: 10X No IslandCoupledCoupled
The figure to the left is JJA precipitation forThe figure to the left is JJA precipitation forboth the No Peninsula case as well as theboth the No Peninsula case as well as theCAM3 Permian control. The monsoonalCAM3 Permian control. The monsoonalprecipitation is clearly still present and in theprecipitation is clearly still present and in thesame approximate location despite the removalsame approximate location despite the removalof the peninsula. This suggests that the land-seaof the peninsula. This suggests that the land-seatemperature gradients are not responsible fortemperature gradients are not responsible forthe precipitation maximum in the 90-150E andthe precipitation maximum in the 90-150E and9-21N monsoon zone9-21N monsoon zone..
The seasonal cycle for the atmospheric velocity potential is evaluated byThe seasonal cycle for the atmospheric velocity potential is evaluated bycomparing JJA-DJF for the 10X Permian Coupled run, the 10X Permian CAM andcomparing JJA-DJF for the 10X Permian Coupled run, the 10X Permian CAM andthe 10X Permian No Peninsula CAM. We are confident that the CAM stand-alonethe 10X Permian No Peninsula CAM. We are confident that the CAM stand-aloneruns accurately represent the atmospheric climate from the CCSM3. Note that theruns accurately represent the atmospheric climate from the CCSM3. Note that theCAM runs were forced by SST data from the coupled run. All three of the aboveCAM runs were forced by SST data from the coupled run. All three of the aboveplots show there is no significant difference between any of these simulations. Thisplots show there is no significant difference between any of these simulations. Thisagain implies that the monsoonal dynamics are not impacted by the removal ofagain implies that the monsoonal dynamics are not impacted by the removal ofland in this region.land in this region.
SSTs for the 10X Permian Coupled and the 10X No Island Coupled on the far left top and middleSSTs for the 10X Permian Coupled and the 10X No Island Coupled on the far left top and middlepanels show the migration and expansion of the warm pool. The precipitation differences can bepanels show the migration and expansion of the warm pool. The precipitation differences can beseen on the bottom panel. Precipitation shifts westward (landward) with the expansion of the warmseen on the bottom panel. Precipitation shifts westward (landward) with the expansion of the warmpool. Interestingly, the removal of the equatorial islands not only allows the expansion of thepool. Interestingly, the removal of the equatorial islands not only allows the expansion of thewarm pool, but also changes the nature of the convective zones along the ITCZ. The center panelswarm pool, but also changes the nature of the convective zones along the ITCZ. The center panelsshow the seasonal cycle of the SST expansion. The warm pool moves significantly westwardshow the seasonal cycle of the SST expansion. The warm pool moves significantly westward(landward) from July through November with the maximum now in October. The seasonal cycle(landward) from July through November with the maximum now in October. The seasonal cycleof the precipitation on the far right panel illustrates once again the spatial and temporal shifts inof the precipitation on the far right panel illustrates once again the spatial and temporal shifts inpeak precipitation.peak precipitation.
The oceanic undercurrent is shown to the right.The oceanic undercurrent is shown to the right.When the equatorial islands are removed andWhen the equatorial islands are removed andocean currents are allowed to flow freely in theocean currents are allowed to flow freely in thePaleo-TeythsPaleo-Teyths Ocean, the undercurrent flattens and Ocean, the undercurrent flattens andextends westward (landward) to ~30E towards theextends westward (landward) to ~30E towards thePangeanPangean coast. Increased coastal surface winds and coast. Increased coastal surface winds andocean stresses directly lee of ocean stresses directly lee of PangeaPangea from 30N to from 30N to30S (not shown) prevent the undercurrent from30S (not shown) prevent the undercurrent fromreaching the coast. These surface stresses alsoreaching the coast. These surface stresses alsoserve to serve to advectadvect cooler water cooler water equatorwardequatorward and andprevent the SST warm pool from ultimatelyprevent the SST warm pool from ultimatelyreaching the coast as well. (Areas not contoured inreaching the coast as well. (Areas not contoured inthe 10X Permian Coupled plot represent landthe 10X Permian Coupled plot represent landareas, i.e. equatorial islands).areas, i.e. equatorial islands).
