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• 21. [Article] Stratospheric Flow during Two Recent Winters Simulated by a Mechanistic Model

  The authors have used a spectral, primitive equation mechanistic model of the stratosphere and mesosphere to simulate observed stratospheric flow through the winters of 1991–92 and 1994–95 by forcing the ...

  Citation × Citation Citation Abstract Copy Title: Stratospheric Flow during Two Recent Winters Simulated by a Mechanistic Model Author: Stott, Peter A., Mote, Philip W., Harwood, Robert S. The authors have used a spectral, primitive equation mechanistic model of the stratosphere and mesosphere to simulate observed stratospheric flow through the winters of 1991–92 and 1994–95 by forcing the model at 100 hPa with observed geopotential height. The authors assess the model’s performance quantitatively by comparing the simulations with the United Kingdom Meteorological Office (UKMO) assimilated stratosphere– troposphere data. Time-mean, zonal-mean temperatures are generally within 5 K and winds within 5 m s⁻¹; transient features, such as wave growth, are mostly simulated well. The phase accuracy of planetary-scale waves declines with altitude and wavenumber, and the model has difficulty correctly simulating traveling anticyclones in the upper stratosphere. The authors examine the minor warming of January 1995 which was unusual in its depth and development and which the model simulated fairly well. The authors also examine the minor warming of January 1992, which the model missed, and a major warming in February 1992 that occurred in the model but not in the observations. Title: Stratospheric Flow during Two Recent Winters Simulated by a Mechanistic Model Author: Stott, Peter A., Mote, Philip W., Harwood, Robert S. The authors have used a spectral, primitive equation mechanistic model of the stratosphere and mesosphere to simulate observed stratospheric flow through the winters of 1991–92 and 1994–95 by forcing the model at 100 hPa with observed geopotential height. The authors assess the model’s performance quantitatively by comparing the simulations with the United Kingdom Meteorological Office (UKMO) assimilated stratosphere– troposphere data. Time-mean, zonal-mean temperatures are generally within 5 K and winds within 5 m s⁻¹; transient features, such as wave growth, are mostly simulated well. The phase accuracy of planetary-scale waves declines with altitude and wavenumber, and the model has difficulty correctly simulating traveling anticyclones in the upper stratosphere. The authors examine the minor warming of January 1995 which was unusual in its depth and development and which the model simulated fairly well. The authors also examine the minor warming of January 1992, which the model missed, and a major warming in February 1992 that occurred in the model but not in the observations. Close

• 22. [Article] Selecting climate change scenarios using impact-relevant sensitivities

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by American Geophysical ...

  Citation × Citation Citation Abstract Copy Title: Selecting climate change scenarios using impact-relevant sensitivities Author: Vano, Julie A., Kim, John B., Rupp, David E., Mote, Philip W. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by American Geophysical Union and published by John Wiley & Sons Ltd. It can be found at: http://agupubs.onlinelibrary.wiley.com/agu/journal/10.1002/%28ISSN%291944-8007/ Title: Selecting climate change scenarios using impact-relevant sensitivities Author: Vano, Julie A., Kim, John B., Rupp, David E., Mote, Philip W. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by American Geophysical Union and published by John Wiley & Sons Ltd. It can be found at: http://agupubs.onlinelibrary.wiley.com/agu/journal/10.1002/%28ISSN%291944-8007/ Close

• 23. [Article] Superensemble regional climate modeling for the western United States

  This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://journals.ametsoc.org/doi/10.1175/BAMS-D-14-00090.1

  Citation × Citation Citation Abstract Copy Title: Superensemble regional climate modeling for the western United States Author: Salahuddin, Ahmed, Rupp, David E., Vickers, Dean, Jones, Richard G., Mote, Philip W., Mera, Roberto, Allen, Myles R., Li, Sihan This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://journals.ametsoc.org/doi/10.1175/BAMS-D-14-00090.1 Title: Superensemble regional climate modeling for the western United States Author: Salahuddin, Ahmed, Rupp, David E., Vickers, Dean, Jones, Richard G., Mote, Philip W., Mera, Roberto, Allen, Myles R., Li, Sihan This is the publisher’s final pdf. The published article is copyrighted by the American Meteorological Society and can be found at: http://journals.ametsoc.org/doi/10.1175/BAMS-D-14-00090.1 Close

• 24. [Article] Evaluation of WRF and HadRM Mesoscale Climate Simulations over the U.S. Pacific Northwest

  This work compares the Weather Research and Forecasting (WRF) and Hadley Centre Regional Model (HadRM) simulations with the observed daily maximum and minimum temperature (Tmax and Tmin) and precipitation ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of WRF and HadRM Mesoscale Climate Simulations over the U.S. Pacific Northwest Author: Salathé, Eric P., Dulière, Valérie, Zhang, Yongxin, Mote, Philip W. This work compares the Weather Research and Forecasting (WRF) and Hadley Centre Regional Model (HadRM) simulations with the observed daily maximum and minimum temperature (Tmax and Tmin) and precipitation at Historical Climatology Network (HCN) stations over the U.S. Pacific Northwest for 2003–07. The WRF and HadRM runs were driven by the NCEP/Department of Energy (DOE) Atmospheric Model Intercomparison Project (AMIP)-II Reanalysis (R-2) data. The simulated Tmax in WRF and HadRM as well as in R-2 compares well with the observations. Predominantly cold biases of Tmax are noted in WRF and HadRM in spring and summer, while in winter and fall more stations show warm biases, especially in HadRM. Large cold biases of Tmax are noted in R-2 at all times. The simulated Tmin compares reasonably well with the observations, although not as well as Tmax in both models and in the reanalysis R-2. Warm biases of Tmin prevail in both model simulations, while R-2 shows mainly cold biases. The R-2 data play a role in the model biases of Tmax, although there are also clear indications of resolution dependency. The model biases of Tmin originate mainly from the regional models. The temporal correlation between the simulated and observed daily precipitation is relatively low in both models and in the reanalysis; however, the correlation increases steadily for longer averaging times. The high-resolution models perform better than R-2, although the nested WRF domains do have the largest biases in precipitation during the winter and spring seasons Title: Evaluation of WRF and HadRM Mesoscale Climate Simulations over the U.S. Pacific Northwest Author: Salathé, Eric P., Dulière, Valérie, Zhang, Yongxin, Mote, Philip W. This work compares the Weather Research and Forecasting (WRF) and Hadley Centre Regional Model (HadRM) simulations with the observed daily maximum and minimum temperature (Tmax and Tmin) and precipitation at Historical Climatology Network (HCN) stations over the U.S. Pacific Northwest for 2003–07. The WRF and HadRM runs were driven by the NCEP/Department of Energy (DOE) Atmospheric Model Intercomparison Project (AMIP)-II Reanalysis (R-2) data. The simulated Tmax in WRF and HadRM as well as in R-2 compares well with the observations. Predominantly cold biases of Tmax are noted in WRF and HadRM in spring and summer, while in winter and fall more stations show warm biases, especially in HadRM. Large cold biases of Tmax are noted in R-2 at all times. The simulated Tmin compares reasonably well with the observations, although not as well as Tmax in both models and in the reanalysis R-2. Warm biases of Tmin prevail in both model simulations, while R-2 shows mainly cold biases. The R-2 data play a role in the model biases of Tmax, although there are also clear indications of resolution dependency. The model biases of Tmin originate mainly from the regional models. The temporal correlation between the simulated and observed daily precipitation is relatively low in both models and in the reanalysis; however, the correlation increases steadily for longer averaging times. The high-resolution models perform better than R-2, although the nested WRF domains do have the largest biases in precipitation during the winter and spring seasons Close

• 25. [Article] Characteristics of stratosphere-troposphere exchange in a general circulation model

  Air and trace gases are exchanged between the stratosphere and the troposphere on a variety of scales; but general circulation models (GCMs) are unable to represent the smaller scales. It would be useful ...

  Citation × Citation Citation Abstract Copy Title: Characteristics of stratosphere-troposphere exchange in a general circulation model Author: Mote, Philip W., Holton, James R., Boville, Byron A. Air and trace gases are exchanged between the stratosphere and the troposphere on a variety of scales; but general circulation models (GCMs) are unable to represent the smaller scales. It would be useful to see how a GCM represents stratosphere-troposphere exchange (STE), both to identify possible model deficiencies which would affect other studies and to see how important the smaller-scale physics might be in the atmosphere itself. Our understanding of observed STE depends largely on inferences from tracer distributions. In this study we examine mass exchange, water vapor exchange, and the behavior of idealized tracers and parcels to diagnose STE in the National Center for Atmospheric Research GCM, the Community Climate Model (CCM2). The CCM2 correctly represents the seasonality of mass exchange across 100 hPa, but values are uniformly too strong. Water vapor, however, indicates that tropical STE is not well represented in the CCM2; even though mean tropopause temperatures are colder than observed, the lower stratosphere is too moist. Most net mass flux occurs at water vapor mixing ratios of about 4-5 parts per million by volume (ppmv), about 1 ppmv too moist. Vertical resolution has little impact on the nature of tropical STE. In midlatitudes, CCM2 more successfully represents STE, which occurs in developing baroclinic waves and stationary anticyclones. Exchange from troposphere to stratosphere does occur but only influences the lowest few kilometers of the extratropical stratosphere, even for tracers with large vertical gradients Title: Characteristics of stratosphere-troposphere exchange in a general circulation model Author: Mote, Philip W., Holton, James R., Boville, Byron A. Air and trace gases are exchanged between the stratosphere and the troposphere on a variety of scales; but general circulation models (GCMs) are unable to represent the smaller scales. It would be useful to see how a GCM represents stratosphere-troposphere exchange (STE), both to identify possible model deficiencies which would affect other studies and to see how important the smaller-scale physics might be in the atmosphere itself. Our understanding of observed STE depends largely on inferences from tracer distributions. In this study we examine mass exchange, water vapor exchange, and the behavior of idealized tracers and parcels to diagnose STE in the National Center for Atmospheric Research GCM, the Community Climate Model (CCM2). The CCM2 correctly represents the seasonality of mass exchange across 100 hPa, but values are uniformly too strong. Water vapor, however, indicates that tropical STE is not well represented in the CCM2; even though mean tropopause temperatures are colder than observed, the lower stratosphere is too moist. Most net mass flux occurs at water vapor mixing ratios of about 4-5 parts per million by volume (ppmv), about 1 ppmv too moist. Vertical resolution has little impact on the nature of tropical STE. In midlatitudes, CCM2 more successfully represents STE, which occurs in developing baroclinic waves and stationary anticyclones. Exchange from troposphere to stratosphere does occur but only influences the lowest few kilometers of the extratropical stratosphere, even for tracers with large vertical gradients Close