HR: 1330h
AN: A53A-02    [Abstracts]
TI: The Diagnosis and application of a convective vorticity vector associated with convective systems
AU: Gao, S
EM: gst@lasg.iap.ac.cn
AF: Laboratory of Cloud-Precipitation Physics and Severe Storms, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China , Huayanli40#building, Chaoyang district, Beijing 100029, China, China
AU: Zhou, Y
EM: zys@mail.iap.ac.cn
AF: Laboratory of Cloud-Precipitation Physics and Severe Storms, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China , Huayanli40#building, Chaoyang district, Beijing 100029, China, China
AU: * Tao, W
EM: tao@agnes.gsfc.nasa.gov
AF: Laboratory for Atmospheres, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA, Laboratory for Atmospheres, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA, United States
AB: Although dry/moist potential vorticity is a very useful and powerful physical quantity in the large scale dynamics, it is not a quite ideal dynamical tool for the study of convective systems or severe storms. A new convective vorticity vector (CVV) is introduced in this study to identify the development of convective systems or severe storms. The daily Aviation (AVN) Model Data is used to diagnose the distribution of the CVV associated with rain storms occurred in the period of Meiyu in 1998. The results have clearly demonstrated that the CVV is an effective vector for indicating the convective actions along the Meiyu front. The CVV also is used to diagnose a 2-D cloud-resolving simulation data associated with 2-D tropical convection. The cloud model is forced by the vertical velocity, zonal wind, horizontal advection, and sea surface temperature obtained from the Tropical cean-Global tmosphere (TOGA) Coupled Ocean-Atmosphere Response Experiment (COARE) and is integrated for a selected 10-day period. The CVV has zonal and vertical components in the 2-D x-z frame. Analysis of zonally averaged and mass-integrated quantities shows that the correlation coefficient between the vertical component of the CVV and the sum of the cloud hydrometeor mixing ratios is 0.81, whereas the correlation coefficient between the zonal component and the sum of the mixing ratios is only 0.18. This indicates that the vertical component of the CVV is closely associated with tropical convection. The tendency equation for the vertical component of the CVV is derived and the zonally averaged and mass-integrated tendency budgets are analyzed. The tendency of the vertical component of the CVV is determined by the interaction between the vorticity and the zonal gradient of cloud heating. The results demonstrate that the vertical component of the CVV is a cloud-linked parameter and can be used to study tropical convection.
DE: 0320 Cloud physics and chemistry
DE: 1704 Atmospheric sciences
DE: 3314 Convective processes
DE: 3332 Mesospheric dynamics
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly