In the existing studies on the atmospheric energy cycle, the attention to thegeneration of available potential energy (APE) is restricted to its global mean value. Thegeographical distributions of the generation of AP...In the existing studies on the atmospheric energy cycle, the attention to thegeneration of available potential energy (APE) is restricted to its global mean value. Thegeographical distributions of the generation of APE and its mechanism of formation are investigatedby using the three-dimensional NCEP/NCAR diabatic heating reanalysis in this study. The results showthat the contributions from sensible heating and net radiation to the generation of zonal andtime-mean APE (G_Z) are mainly located in high and middle latitudes with an opposite sign, while thelatent heating shows a dominant effect on G_Z mainly in the tropics and high latitudes where thecontributions from the middle and upper tropospheres are also contrary to that from the lowtroposphere. In high latitudes, the G_Z is much stronger for the Winter Hemisphere than for theSummer Hemisphere, and this is consistent with the asymmetrical feature shown by the reservoir ofzonal and time-mean APE in two hemispheres, which suggests that the generation of APE plays afundamental role in maintaining the APE in the global atmospheric energy cycle. The samecontributions to the generation of stationary eddy APE (G_(SE)) from the different regions relatedto the maintenance of longitudinal temperature contrast are likely arisen by different physics.Specifically, the positive contributions to G_(SE) from the latent heating in the western tropicalPacific and from the sensible heating over land are dominated by the heating at warm regions,whereas those from the latent heating in the eastern tropical Pacific and from the sensitive heatingover the oceans are dominated by the cooling at cold regions. Thus, our findings provide anobservational estimate of the generation of eddy APE to identify the regional contributions in theclimate simulations because it might be correct for the wrong reasons in the general circulationmodel (GCM). The largest positive contributions to the generation of transient eddy APE (G_(TE)) arefound to be at middle latitudes in the middle and upper tropospheres, where reside the strong localcontributions to the baroclinic conversion from transient eddy APE to transient eddy kinetic energyand the resulting transient eddy kinetic energy.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos. 40175028 and 40475045.
文摘In the existing studies on the atmospheric energy cycle, the attention to thegeneration of available potential energy (APE) is restricted to its global mean value. Thegeographical distributions of the generation of APE and its mechanism of formation are investigatedby using the three-dimensional NCEP/NCAR diabatic heating reanalysis in this study. The results showthat the contributions from sensible heating and net radiation to the generation of zonal andtime-mean APE (G_Z) are mainly located in high and middle latitudes with an opposite sign, while thelatent heating shows a dominant effect on G_Z mainly in the tropics and high latitudes where thecontributions from the middle and upper tropospheres are also contrary to that from the lowtroposphere. In high latitudes, the G_Z is much stronger for the Winter Hemisphere than for theSummer Hemisphere, and this is consistent with the asymmetrical feature shown by the reservoir ofzonal and time-mean APE in two hemispheres, which suggests that the generation of APE plays afundamental role in maintaining the APE in the global atmospheric energy cycle. The samecontributions to the generation of stationary eddy APE (G_(SE)) from the different regions relatedto the maintenance of longitudinal temperature contrast are likely arisen by different physics.Specifically, the positive contributions to G_(SE) from the latent heating in the western tropicalPacific and from the sensible heating over land are dominated by the heating at warm regions,whereas those from the latent heating in the eastern tropical Pacific and from the sensitive heatingover the oceans are dominated by the cooling at cold regions. Thus, our findings provide anobservational estimate of the generation of eddy APE to identify the regional contributions in theclimate simulations because it might be correct for the wrong reasons in the general circulationmodel (GCM). The largest positive contributions to the generation of transient eddy APE (G_(TE)) arefound to be at middle latitudes in the middle and upper tropospheres, where reside the strong localcontributions to the baroclinic conversion from transient eddy APE to transient eddy kinetic energyand the resulting transient eddy kinetic energy.
