气象学报2017，Vol.75Issue(3)：517-526,10.DOI:10.11676/qxxb2017.036
从不稳定能量角度对条件不稳定相关问题的讨论
A discussion about the conditional instability from the perspective of unstable energy
摘要
Abstract
Most of local deep convections are initiated in a conditionally unstable environment.Thereby it is necessary to consider the influence of a deep air layer to the air parcel that rises from the base level.Some questions related to conditional instability, such as the unstable energy and Convective Available Potential Energy (CAPE), are discussed from the perspective of energy.In addition, the relationship between the moist static energy of a single surface station and the unstable energy in a conditionally unstable environment is analyzed based on a case study using observational data.The main results are as follows.(1) From the perspective of energy, the original definition of CAPE should be followed.That means CAPE is equal to the difference between positive and negative unstable energy.The lifting velocity in the lower level associated with the kinetic energy is implicitly included in the formulation of original CAPE, which is helpful for forecasting severe convective weather, especially in South China in the warm season.(2) The moist static energy remains constant when the air parcel is lifted from low to high levels during both the dry adiabatic and moist adiabatic processes, which indicates that the variation of total energy is only related to the variation of kinetic energy caused by external forcing.There exists no transformation from moist static energy to kinetic energy.(3) Temporal variation of the moist static energy at a single surface station indicates the variation of positive and negative unstable energy, which is closely related to the calculation of unstable energy.Such temporal variations at various stations can make up for the weaknesses caused by coarse resolution of soundings and the deficiency of hourly data of positive and negative unstable energy.关键词
条件不稳定/不稳定能量/对流有效位能/湿静力能Key words
Conditional instability/Unstable energy/CAPE/Moist static energy分类
天文与地球科学引用本文复制引用
章丽娜,周小刚,徐丽娅..从不稳定能量角度对条件不稳定相关问题的讨论[J].气象学报,2017,75(3):517-526,10.基金项目
国家自然科学基金项目(41475042)、我国华南春季对流性大风监测预报关键技术研究(GYHY201406002)、国家科技支撑计划项目(2015BAC03B06). （41475042）
