Sunday, 9 February 2003
The Relationship between the initial trigger and the final state for the convectively unstable Atmosphere
This paper uses cloud-resolving model WRF (Weather Research and Forecasting model) to simulate the convection in the convectively unstable atmosphere and to study the relationship between the final state of the air and the initial trigger that activates the convection. The results show the well-developed cells. At final state the air is balanced between the lifting, instability and moisture of the air. Lacking of anyone of these three ingredients necessary for convection is not going to have convection any more. At final state, the total CAPE released is proportional to the strength of the initial bubble. The kinetic energy, the vertical distribution patterns of moisture and moist static energy (MSE) also show their coherent relationship with the strength of the initial bubble. When the strength of the initial bubble reaches a particular point, the final state varies near an equilibrium state, i.e. no linear relationship exits between the strength of the initial bubble and the released CAPE, the left moisture and the kinetic energy. Over the disturbed area, the differences at final state or during the evolution between different cases are much smaller than those over the whole domain. The cases with surface moisture flux show different results from the cases without surface heat and moisture flux. They have more CAPE left, more moisture hold in the air and more latent heating happen at mid-layer. Comparing the case with surface flux over ocean to the case over land, the results show similar results.
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