Lightning and convection parameterisations – uncertainties in global modelling
نویسندگان
چکیده
The simulation of convection, lightning and consequent NO x emissions with global atmospheric chemistry models is associated with large uncertainties since these processes are heavily parameterised. Each parameterisation by itself has deficiencies and the combination of these substantially increases the uncertainties compared to the individual parameterisations. In this study several combinations of state-of-the-art convection and lightning parameterisations are used in simulations with the global atmospheric chemistry general circulation model ECHAM5/MESSy, and are evaluated against lightning observations. A wide range in the spatial and temporal variability of the simulated flash densities is found, attributed to both types of parameteri-sations. Some combinations perform well, whereas others are hardly applicable. In addition to resolution dependent rescaling parameters, each combination of lightning and con-vection schemes requires individual scaling to reproduce the observed flash frequencies. The resulting NO x profiles are inter-compared, however definite conclusions about the most realistic profiles can currently not be drawn.
منابع مشابه
Global convection modelling
Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion EGU Abstract In global models of the atmosphere convection is parameterised, since the typical scale of this process is smaller than the model resolution. Here we address some of the uncertainties arising from the selection of different algorithms to simulate this proc...
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