Evaluation and intercomparison of global atmospheric transport models using Rn-222 and other short-lived tracers

Jacob, DJ and Prather, MJ and Rasch, PJ and Shia, RL and Balkanski, YJ and Beagley, [No Value] and Bergmann, DJ and Blackshear, WT and Brown, M and Chiba, M and Chipperfield, MP and deGrandpre, J and Dignon, JE and Feichter, J and Genthon, C and Grose, WL and Kasibhatla, PS and Kohler, J. and Kritz, MA and Law, K and Penner, JE and Ramonet, M and Reeves, CE and Rotman, DA and Stockwell, DZ and VanVelthoven, PFJ and Verver, G and Wild, O and Yang, H and Zimmermann, P (1997) Evaluation and intercomparison of global atmospheric transport models using Rn-222 and other short-lived tracers. Journal of Geophysical Research: Atmospheres, 102 (D5). pp. 5953-5970. ISSN 0747-7309

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Simulations of Rn-222 and other short-lived tracers are used to evaluate and intercompare the representations of convective and synoptic processes in 20 global atmospheric transport models. Results show that most established three-dimensional models simulate vertical mixing in the troposphere to within the constraints offered by the observed mean Rn-222 concentrations and that subgrid parameterization of convection is essential for this purpose. However, none of the models captures the observed variability of Rn-222 concentrations in the upper troposphere, and none reproduces the high Rn-222 concentrations measured at 200 hPa over Hawaii. The established three-dimensional models reproduce the frequency and magnitude of high- Rn-222 episodes observed at Crozet Island in the Indian Ocean, demonstrating that they can resolve the synoptic-scale transport of continental plumes with no significant numerical diffusion. Large differences between models are found in the rates of meridional transport in the upper troposphere (interhemispheric exchange, exchange between tropics and high latitudes). The four two-dimensional models which participated in the intercomparison tend to underestimate the rate of vertical transport from the lower to the upper troposphere but show concentrations of Rn-222 in the lower troposphere that are comparable to the zonal mean values in the three-dimensional models.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Geophysical Research: Atmospheres
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Copyright 1997 by the American Geophysical Union
?? zonally averaged circulationseasonal-variationnongeostrophic theorygeneral-circulation modeltropospheric ozone3-dimensional simulationodd nitrogentwo-dimensional modelclimate modelmiddle atmosphere ??
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05 Apr 2013 12:32
Last Modified:
04 Jun 2024 00:19