Atmospheric Chemistry and Physics
www.atmos-chem-phys.net
1680-7316
1680-7324
6
10
2006
10.5194/acp-6-2895-2006
http://www.atmos-chem-phys.net/6/2895/2006/
http://www.atmos-chem-phys.net/6/2895/2006/acp-6-2895-2006.html
http://www.atmos-chem-phys.net/6/2895/2006/acp-6-2895-2006.pdf
2895
2910
2006-07-12
Meteorological implementation issues in chemistry and transport models
S. E. Strahan
sstrahan@pop600.gsfc.nasa.gov
B. C. Polansky
University of Maryland Baltimore County, Goddard Earth Science and Technology Center, 5523 Research Park Dr., Suite 320, Baltimore, MD, 21228, USA
Science Systems and Applications, Inc., 10210 Greenbelt Rd., Suite 600, Lanham, MD, 20706, USA
Offline chemistry and transport models (CTMs) are
versatile tools for studying composition and climate issues requiring
multi-decadal simulations. They are computationally fast compared to coupled
chemistry climate models, making them well-suited for integrating
sensitivity experiments necessary for understanding model performance and
interpreting results. The archived meteorological fields used by CTMs can be
implemented with lower horizontal or vertical resolution than the original
meteorological fields in order to shorten integration time, but the effects
of these shortcuts on transport processes must be understood if the CTM is
to have credibility. In this paper we present a series of sensitivity
experiments on a CTM using the Lin and Rood advection scheme, each differing
from another by a single feature of the wind field implementation. Transport
effects arising from changes in resolution and model lid height are
evaluated using process-oriented diagnostics that intercompare CH<sub>4</sub>,
O<sub>3</sub>, and age tracer carried in the simulations. Some of the diagnostics
used are derived from observations and are shown as a reality check for the
model. Processes evaluated include tropical ascent, tropical-midlatitude
exchange, poleward circulation in the upper stratosphere, and the
development of the Antarctic vortex. We find that faithful representation of
stratospheric transport in this CTM is possible with a full mesosphere,
~1 km resolution in the lower stratosphere, and relatively low
vertical resolution (>4 km spacing) in the middle stratosphere and above,
but lowering the lid from the upper to lower mesosphere leads to less
realistic constituent distributions in the upper stratosphere. Ultimately,
this affects the polar lower stratosphere, but the effects are greater for
the Antarctic than the Arctic. The fidelity of lower stratospheric transport
requires realistic tropical and high latitude mixing barriers which are
produced at 2°×2.5°, but not lower resolution. At
2°×2.5° resolution, the CTM produces a vortex capable of isolating
perturbed chemistry (e.g. high Cl<sub>y</sub> and low NO<sub>y</sub>) required for
simulating polar ozone loss.
Austin, J.: A three-dimensional coupled chemistry-climate model simulation of past stratospheric trends, J. Atmos. Sci., 59, 218–232, 2002.
Austin, J. and Butchart, N.: Coupled chemistry-climate model simulations for the period 1980 to 2020: Ozone depletion and the start of ozone recovery, Q. J. R. Meteorol. Soc., 129, 3225–3249, 2003.
Bregman, A., Krol, M. C., Teyssedre, H., Norton, W. A., Iwi, A., Chipperfield, M., Pitari, G., Sundet, J. K., and Lelieveld, J.: Chemistry-transport model comparison with ozone observations in the midlatitude lowermost stratosphere, J. Geophys. Res., 106, 17 479–17 496, 2001.
Considine, D. B., Connell, P. S., Bergmann, D. J., Rotman, D. A., and Strahan, S. E.: Sensitivity of Global Modeling Initiative model predictions of Antarctic ozone recovery to input meteorological fields, J. Geophys. Res., 109, D15301, doi:10.1029/2003JD004487, 2004.
Douglass, A. R., Prather, M. J., Hall, T. M., Strahan, S. E., Rasch, P. J., Sparling, L. C., Coy, L., and Rodriguez, J. M.: Choosing meteorological input for the global modeling initiative assessment of high-speed aircraft, J. Geophys. Res., 104, 27 545–27 564, 1999.
Douglass, A. R., Schoeberl, M. R., Rood, R. B., and Pawson, S.: Evaluation of transport in the lower tropical stratosphere in a global chemistry and transport model, J. Geophys. Res., 108, 4259, doi:10.1029/2002JD002696, 2003.
Douglass, A. R., Stolarski, R. S., Strahan, S. E., and Connell, P. S.: Radicals and reservoirs in the GMI chemistry and transport model: Comparison to measurements, J. Geophys. Res., 109, D16302, doi:10.1029/2004JD004632, 2004.
Fleming, E. L., Jackman, C. H., Stolarski, R. S., and Considine, D. B.: Simulation of stratospheric tracers using an improved empirically based two-dimensional model transport formulation, J. Geophys. Res., 104, 23 911–23 934, 1999.
Hall, T. M., Waugh, D. W., Boering, K. A., and Plumb, R. A.: Evaluation of transport in stratospheric models, J. Geophys. Res., 104, 18 815–18 839, 1999.
IPCC: Climate Change 2001: The scientific basis, The third assessment report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, UK, 2001.
Lin, S.-J. and Rood, R. B: Multidimensional flux form semi-Lagrangian transport schemes, Mon. Wea. Rev., 124, 2046–2070, 1996.
Lin, S.-J.: A vertically Lagrangian finite-volume dynamical core for global models, Mon Wea. Rev., 132, 2293–2307, 2004.
MacKenzie, I. A. and Harwood, R. S.: Arctic ozone destruction and chemical-radiative interaction, J. Geophys. Res., 105, 9033–9051, 2000.
Mote, P. W., Rosenlof, K. H., McIntyre, M. C., et al.: An atmospheric tape recorder: The imprint of tropical tropopause temperatures on stratospheric water vapor, J. Geophys. Res., 101, 3989–4006, 1996.
Park, J. H., Gordley, L. L., Drayson, S. R., et al.: Validation of halogen occultation experiment CH$_4$ measurements from the UARS, J. Geophys. Res., 101, 10 183–10 205, 1996.
Plumb, R. A.: A "tropical pipe" model of stratospheric transport, J. Geophys. Res., 101, 3957–3972, 1996.
Prather, M. H.: Numerical advection by conservation of second-order moments, J. Geophys. Res., 91, 6671–6681, 1986.
Rasch, P. J., Tie, X., Boville, B. A., and Williamson, D. L.: A three-dimensional transport model for the middle atmosphere, J. Geophys. Res., 99, 999–1017, 1994.
Roche, A. E., Kumer, J. B., Nightingale, J. L., et al.: Validation of CH$_4$ and N$_2$O measurements by the CLAES instrument on the Upper Atmosphere Research Satellite, J. Geophys. Res., 101, 9679–9710, 1996.
Rood, R. B.: Numerical advection algorithms and their role in atmospheric transport and chemistry models, Rev. Geophys., 25, 71–100, 1987.
Rosenfield, J. E. and Schoeberl, M. R.: On the origin of polar vortex air, J. Geophys. Res., 106, 33 485–33 497, 2001.
Rotman, D. A., Tannahill, J. R., Kinnison, D. E., et al.: Global Modeling Initiative assessment model: Model description, integration, and testing of the transport shell, J. Geophys. Res., 106, 1669–1691, 2001.
Russell, G. L. and Lerner, J. A.: A new finite-differencing scheme for the tracer transport equation, J. Appl. Meteorol., 20, 1483–1298, 1981.
Ruth, S., Kennaugh, R., and Gray, L. J.: Seasonal, semiannual, and interannual variability seen in measurements of methane made by the UARS Halogen Occultation Experiment, J. Geophys. Res., 102, 16 189–16 199, 1997.
Searle, K. R., Chipperfield, M. P., Bekki, S., and Pyle, J. A.: The impact of spatial averaging on calculated polar ozone loss, 1. Model experiments, J. Geophys. Res., 103, 25 397–25 408, 1998.
Sparling, L.: Statistical perspectives on stratospheric transport, Rev. Geophys., 38, 417–436, 2000.
Strahan, S. E. and Douglass, A. R.: Evaluating the credibility of transport processes in simulations of ozone recovery using the Global Modeling Initiative three-dimensional model, J. Geophys. Res., D05110, doi:10.1029/2003JD004238, 2004.
Stolarski, R. S., Douglass, A .R., Steenrod, S. D., and Pawson, S.: Trends in stratospheric ozone: Lessons learned from a 3-D chemical transport model, J. Atmos. Sci., 63, 1028–1041, 2006.
Tian, W. S. and Chipperfield, M. P.: A new coupled chemistry-climate model for the stratosphere: The importance of coupling for future O$_3$-climate predictions, Q. J. R. Meteorol. Soc, 131, 281–303, 2005.
Van den Broek, M. M. P., van Aalst, M. K., Bregman, A., et al.: The impact of model grid zooming on tracer transport in the 1999/2000 Arctic polar vortex, Atmos. Chem. Phys., 3, 1833–1847, 2003.
Waugh, D. W. and Plumb, R. A.: Contour advection with surgery: A technique for investigating finescale structure in tracer transport, J. Atmos. Sci, 51, 530–540, 1994.
Waugh, D. W., Hall, T. M., Randel, W. J., et al.: Three-dimensional simulations of long-lived tracer using winds from MACCM2, J. Geophys. Res., 102, 21 493–21 513, 1997.
Williamson, D. L. and Rasch, P. J.: Two-dimensional semi-Lagrangian transport with shape preserving interpolation, Mon. Wea. Res., 117, 102–129, 1989.