The importance of vertical resolution in the free troposphere for modeling intercontinental plumes

Abstract. Chemical plumes in the free troposphere can preserve their identity for more than a week as they are transported on intercontinental scales. Current global models cannot reproduce this transport. The plumes dilute far too rapidly due to numerical diffusion in sheared flow. We show how model accuracy can be limited by either horizontal resolution ( Δx ) or vertical resolution ( Δz ). Balancing horizontal and vertical numerical diffusion, and weighing computational cost, implies an optimal grid resolution ratio ( Δx ∕ Δz ) opt ∼  1000 for simulating the plumes. This is considerably higher than current global models ( Δx ∕ Δz ∼  20) and explains the rapid plume dilution in the models as caused by insufficient vertical resolution. Plume simulations with the Geophysical Fluid Dynamics Laboratory Finite-Volume Cubed-Sphere Dynamical Core (GFDL-FV3) over a range of horizontal and vertical grid resolutions confirm this limiting behavior. Our highest-resolution simulation ( Δx ≈  25 km, Δz ≈  80 m) preserves the maximum mixing ratio in the plume to within 35 % after 8 days in strongly sheared flow, a drastic improvement over current models. Adding free tropospheric vertical levels in global models is computationally inexpensive and would also improve the simulation of water vapor.

[1]  Christiane Jablonowski,et al.  Rotated Versions of the Jablonowski Steady‐State and Baroclinic Wave Test Cases: A Dynamical Core Intercomparison , 2010 .

[2]  L. Horowitz,et al.  Transport of Asian ozone pollution into surface air over the western United States in spring , 2012 .

[3]  D. Jacob,et al.  Sources contributing to background surface ozone in the US Intermountain West , 2013 .

[4]  A. Stohl,et al.  On the pathways and timescales of intercontinental air pollution transport , 2002 .

[5]  Thomas T. Warner,et al.  Numerical Weather and Climate Prediction , 2011 .

[6]  D. Keyser,et al.  The effect of spatial resolution on the simulation of upper-tropospheric frontogenesis using a sigma-coordinate primitive equation model , 1989 .

[7]  R. Somerville,et al.  Sensitivity of Cloud and Radiation Parameterizations to Changes in Vertical Resolution , 2000 .

[8]  D. Jacob,et al.  Transpacific Transport of Asian Anthropogenic Aerosols and its Impact on Surface Air Quality in the United States , 2006 .

[9]  Daniel J. Jacob,et al.  Modeling of Atmospheric Chemistry , 2017 .

[10]  K. Emanuel,et al.  The vertical resolution sensitivity of simulated equilibrium temperature and water‐vapour profiles , 2007 .

[11]  A. Maurizi,et al.  Effects of resolution on the relative importance of numerical and physical horizontal diffusion in atmospheric composition modelling , 2009 .

[12]  D. Jacob,et al.  Impact of Asian emissions on observations at Trinidad Head, California, during ITCT 2K2 , 2004 .

[13]  W. Ingram,et al.  On the robustness of the water vapor feedback: GCM vertical resolution and formulation , 2002 .

[14]  Michael S. Fox-Rabinovitz,et al.  Consistent vertical and horizontal resolution , 1989 .

[15]  R. F. Warming,et al.  The modified equation approach to the stability and accuracy analysis of finite-difference methods , 1974 .

[16]  Merritt N. Deeter,et al.  Asian Outflow and Trans-Pacific Transport of Carbon Monoxide and Ozone Pollution: An Integrated Satellite, Aircraft, and Model Perspective , 2003 .

[17]  R. Lucchesi,et al.  File Specification for GEOS-5 FP (Forward Processing) , 2013 .

[18]  M. Odman.  A quantitative analysis of numerical diffusion introduced by advection algorithms in air quality models , 1997 .

[19]  James Kent,et al.  Dynamical core model intercomparison project: Tracer transport test cases , 2014 .

[20]  D. Jacob,et al.  Errors and improvements in the use of archived meteorological data for chemical transport modeling , 2017 .

[21]  K. F. Boersma,et al.  Transpacific transport of ozone pollution and the effect of recent Asian emission increases on air quality in North America: an integrated analysis using satellite, aircraft, ozonesonde, and surface observations , 2008 .

[22]  D. Jacob,et al.  Summertime influence of Asian pollution in the free troposphere over North America , 2007 .

[23]  J. Holton.  An introduction to dynamic meteorology , 2004 .

[24]  John Y. N. Cho,et al.  General characteristics of tropospheric trace constituent layers observed in the MOZAIC program , 2000 .

[25]  Shian‐Jiann Lin.  A “Vertically Lagrangian” Finite-Volume Dynamical Core for Global Models , 2004 .

[26]  Jian Lu,et al.  High Resolution Model Intercomparison Project (HighResMIP v1.0) for CMIP6 , 2016 .

[27]  James Kent,et al.  Assessing Tracer Transport Algorithms and the Impact of Vertical Resolution in a Finite-Volume Dynamical Core , 2012 .

[28]  D. Jacob,et al.  Ozone production in transpacific Asian pollution plumes and implications for ozone air quality in California , 2004, Journal of Geophysical Research: Atmospheres.

[29]  John Methven,et al.  The Advection of High-Resolution Tracers by Low-Resolution Winds , 1999 .

[30]  D. Durran.  Numerical Methods for Fluid Dynamics: With Applications to Geophysics , 2010 .

[31]  D. Jacob,et al.  Biomass‐burning emissions and associated haze layers over Amazonia , 1988 .

[32]  Christiane Jablonowski.  Idealized test cases for the dynamical cores of Atmospheric General Circulation Models : A proposal for the NCAR ASP 2008 summer colloquium , 2008 .

[33]  D. Jacob,et al.  Global modeling of tropospheric chemistry with assimilated meteorology : Model description and evaluation , 2001 .

[34]  Oliver Wild,et al.  Global tropospheric ozone modeling: Quantifying errors due to grid resolution , 2006 .

[35]  M. Deeter,et al.  Relationship between Measurements of Pollution in the Troposphere (MOPITT) and in situ observations of CO based on a large‐scale feature sampled during TRACE‐P , 2004 .

[36]  Shian‐Jiann Lin,et al.  Multidimensional Flux-Form Semi-Lagrangian Transport Schemes , 1996 .

[37]  D. Dritschel,et al.  Effect of Prandtl’s ratio on balance in geophysical turbulence , 2015, Journal of Fluid Mechanics.

[38]  J. Marsden,et al.  Introduction to Dynamics , 1983 .

[39]  V. Pope,et al.  The representation of water vapor and its dependence on vertical resolution in the Hadley Centre Climate Model , 2001 .

[40]  D. Jacob,et al.  Errors and improvements in the use of archived meteorological data for chemical transport modeling: an analysis using GEOS-Chem v11-01 driven by GEOS-5 meteorology. , 2018, Geoscientific model development.

[41]  D. Durran.  Numerical Methods for Fluid Dynamics , 2010 .

[42]  V. Thouret,et al.  Observations of ozone transport from the free troposphere to the Los Angeles basin , 2012 .

[43]  H. T. Huynh.  Schemes and constraints for advection , 1997 .

[44]  John Y. N. Cho,et al.  Ubiquity of quasi-horizontal layers in the troposphere , 1999, Nature.

[45]  Chao Yang,et al.  10M-Core Scalable Fully-Implicit Solver for Nonhydrostatic Atmospheric Dynamics , 2016, SC16: International Conference for High Performance Computing, Networking, Storage and Analysis.

[46]  Shian-Jiann Lin,et al.  Finite-volume transport on various cubed-sphere grids , 2007, J. Comput. Phys..

[47]  P. Lauritzen,et al.  Dynamical Core Model Intercomparison Project ( DCMIP 2016 ) Test Case Document , 2016 .

[48]  Michael P. Brenner,et al.  Resolving intercontinental pollution plumes in global models of atmospheric transport , 2010 .

[49]  D. Williamson,et al.  A baroclinic instability test case for atmospheric model dynamical cores , 2006 .

[50]  John Y. N. Cho,et al.  Measurements of atmospheric layers from the NASA DC‐8 and P‐3B aircraft during PEM‐Tropics A , 1999 .

[51]  Daniel J. Jacob,et al.  Limits on the ability of global Eulerian models to resolve intercontinental transport of chemical plumes , 2016 .

[52]  A. N. Semakin,et al.  Numerical Simulation of Global-Scale Atmospheric Chemical Transport with High-Order Wavelet-Based Adaptive Mesh Refinement Algorithm , 2016 .

[53]  Stephan Hoyer,et al.  xarray: N-D labeled arrays and datasets in Python , 2017 .

[54]  Andrea Klug,et al.  Numerical Methods For Fluid Dynamics With Applications To Geophysics , 2016 .

[55]  V. Balaji,et al.  Climate Computing: The State of Play , 2015, Computing in Science & Engineering.

[56]  E. Atlas,et al.  Gas-phase chemical characteristics of Asian emission plumes observed during ITCT 2K2 over the eastern North Pacific Ocean , 2004 .

[57]  Richard B. Rood,et al.  An assimilated dataset for Earth science applications , 1993 .

[58]  Bram van Leer,et al.  High-order finite-volume methods for the shallow-water equations on the sphere , 2010, J. Comput. Phys..

[59]  K. Nechvíle.  The High Resolution , 2005 .

[60]  P. H. Lauritzena,et al.  Evaluating advection / transport schemes using interrelated tracers , scatter plots and numerical mixing diagnostics , 2011 .