On the use of mass-conserving wind fields in chemistry-transport models

[摘要] A new method has been developed that provides mass-conserving wind fields forglobal chemistry-transport models. In previous global Eulerian modeling studies a mass-imbalance was found between the model mass transport and thesurface pressure tendencies. Several methods have been suggested to correctfor this imbalance, but so far no satisfactory solution has been found. Ournew method solves these problems by using the wind fields in a spherical harmonical form (divergence and vorticity) by mimicing the physics of theweather forecast model as closely as possible. A 3-D chemistry-transport modelwas used to show that the calculated ozone fields with the new processing method agree remarkably better with ozone observations in the uppertroposphere and lower stratosphere. In addition, the calculated age of air inthe lower stratosphere show better agreement with observations, although theair remains still too young in the extra-tropical stratosphere.

[学科分类] 大气科学