Convective available potential energy

About: Convective available potential energy is a research topic. Over the lifetime, 936 publications have been published within this topic receiving 43773 citations. The topic is also known as: CAPE.

Study of Mesoscale Convective System in Heavy Rainstorm Process at a Cold Vortex Development Stage

Abstract: Using the observation data of Northeastern China heavy rainstorm experiment in 2009,conventional observation data from meteorological observation,automatic weather station,FY-2C satellite and NCEP reanalysis data,synoptic scale characteristic,mesoscale convective system and severe convective trigger mechanism of mesoscale convective system during a heavy rainstorm process in Northeastern China on 19 June 2009 are analyzed and a three-dimension concept model of the rainstorm process during the development of the cold vortex is summarized.The results show that,the heavy rainfall mainly happened in the development state of the cold vortex,and there were small scale,suddenness features,which with typical meso β-γ scale characteristics.High temperature,high relative humidity,geopotential unstable layer and high vapor tongue stretched toward the northwest in the low level and the dry air incursion in the middle level provide the extraordinary favorable environment condition for the development of the convective system.The configuration of the two upper level jets intensifys the divergence above the convective area,coupling with the ahead of the lower level jets on the south side of convergence zone,which strengthens the rising stream of the storm.Sountherly lower level jet of exit region on the south side of upper level jet enhances the inflow intensity of storm which provide the plenty of vapor for the convective systems.The dry air incursion of middle level of western rainstorm make the cold dry air to be rapidly trans port the convective strom occurrence area,which leads to thermo-inversion layer.Before the convective system happened,the thermo-inversion layer of middle and lower levels the dry layer of upper level is separated,which accumulates the unstable energy of the storm.The low level northwest horizon wind strengthens the convergence of surface stream field,which is the key factor of initial convective systems.

Probing for overshooting as extreme event of thunderstorms

Abstract: Thunderstorm overshooting is rare but not an unusual phenomenon in a metropolitan of India, Kolkata (22.57° N; 88.36° E) during the pre-monsoon months (April–May). An attempt is made in this study to identify the important parameters differentiating the thunderstorms in overshooting and non-overshooting categories through data analytics from 2000 to 2015. The present investigation on parametric classification would facilitate in estimating the predictability of thunderstorms with overshooting which subsequently might assist in operational forecast of thunderstorm severity over Kolkata. The altitudes of lifting condensation level (LCL), wind shear, bulk Richardson number (BRN), gust speed, boundary layer characteristics and their correlation with thunderstorm cloud top height (CTH) and also their variation and distribution during overshooting (OTS) and non-overshooting (TS) thunderstorms are analyzed in this study. The result depicts that over Kolkata the intensity of storms during OTS is higher than during TS though the frequency of OTS is less than that of TS. The results further show that the potential temperature (θ), equivalent potential temperature (θe), mixing ratio (es) in the boundary layer, convective available potential energy, convective inhibition energy, BRN and gust speed play significant roles in regulating the CTH during OTS and TS thunderstorms over Kolkata.

Convective Available Potential Energy and Precipitation in a Cloud-Resolving Model Simulation of Indian Summer Monsoon

Abstract: Relationship between convective available potential energy (CAPE) and precipitation is explored in a season-long cloud-resolving model (CRM) simulation of Indian summer monsoon. The location of maximum precipitation and CAPE does not always coincide in a CRM simulation. The diurnal land surface heating is shown to have an effect on CAPE and precipitation over ocean. Convective inhibition energy is shown to have a significant effect on the location of precipitation. It is shown that mass flux parameterizations which depend on CAPE consumption do not get the location or magnitude of precipitation right at CRM resolution. It is emphasized that once the model resolution starts approaching cloud scale, the basic assumption of convective quasi-equilibrium is not sufficient and representation of organized mesoscale convective systems becomes imperative. Present-day cumulus parameterizations do not include any representation of organized mesoscale convective systems. We show that CAPE consumed by these systems not only triggers vertical motion but also contributes to horizontal motion of the system.

NOTES AND CORRESPONDENCE Thermodynamics of Eastern Mediterranean Rainfall Variability

Abstract: This note focuses on thermodynamic changes caused by Eastern Mediterranean (EM) subsidence anomalies. Subsidence anomalies are shown to modulate EM-wide stability with respect to moist ascent. Additionally, convective available potential energy (CAPE) generation rates, as well as mean CAPE, change coherently during extreme EM rainfall anomalies. It is suggested that the resulting modulation of convective rain generation is the process directly responsible for the observed rainfall anomalies.