scispace - formally typeset
Search or ask a question
Topic

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.


Papers
More filters
Journal ArticleDOI
01 Mar 2009-Tellus A
TL;DR: A narrow line of convective showers was observed over southern England on 18 July 2005 during the Convective Storm Initiation Project (CSIP) as discussed by the authors, where the showers formed behind a cold front (CF), beneath two apparently descending dry layers (i.e. sloping so that they descended relative to the instruments observing them).
Abstract: A narrow line of convective showers was observed over southern England on 18 July 2005 during the Convective Storm Initiation Project (CSIP). The showers formed behind a cold front (CF), beneath two apparently descending dry layers (i.e. sloping so that they descended relative to the instruments observing them). The lowermost dry layer was associated with a tropopause fold from a depression, which formed 2 d earlier from a breaking Rossby wave, located northwest of the UK. The uppermost dry layer had fragmented from the original streamer due to rotation around the depression (This rotation was also responsible for the observations of apparent descent—ascent would otherwise be seen behind a CF). The lowermost dry layer descended over the UK and overran higher θ w air beneath it, resulting in potential instability. Combined with a surface convergence line (which triggered the convection but had less impact on the convective available potential energy than the potential instability), convection was forced up to 5.5 km where the uppermost dry layer capped it. The period when convection was possible was very short, thus explaining the narrowness of the shower band. Convective Storm Initiation Project observations and model data are presented to illustrate the unique processes in this case.

12 citations

01 Jan 2008
TL;DR: In this article, a review of cloud modeling in the tropical deep convective regime is reviewed based on the author's research work, focusing on model setup, cloud-radiation interaction processes, convective-radiative processes associated with the diurnal variation of tropical oceanic convection, dominant cloud microphysical processes producing precipitation, precipitation efficiency, physical processes responsible for the phase relation between surface rain rate and convective available potential energy, and the effects of precipitation on the tropical upper ocean.
Abstract: Understanding cloud processes and the associated interactions with their environment is crucial for better predictions of tropical climate. The cloud-resolving model is demonstrated to be a powerful tool for process studies. In this paper, cloud modeling in the tropical deep convective regime is reviewed based on the author's research work. The review focuses on model setup, cloud-radiation interaction processes, convective-radiative processes associated with the diurnal variation of tropical oceanic convection, dominant cloud microphysical processes producing precipitation, precipitation efficiency, physical processes responsible for the phase relation between surface rain rate and convective available potential energy, and the effects of precipitation on the tropical upper ocean.

12 citations

01 Dec 2011
TL;DR: In this article, the current distribution of severe thunderstorms as a function of large-scale environmental conditions is presented, and it is shown that the intensity of tornadoes and large hail, given that they occur, tends to be almost entirely dependent on the convective available potential energy (CAPE) and deep-tropospheric wind shear.
Abstract: As the planet warms, it is important to consider possible impacts of climate change on severe thunderstorms and tornadoes. To further that discussion, the current distribution of severe thunderstorms as a function of large-scale environmental conditions is presented. Severe thunderstorms are much more likely to form in environments with large values of convective available potential energy (CAPE) and deep-tropospheric wind shear. Tornadoes and large hail are preferred in high-shear environments and non-tornadic wind events in low shear. Further, the intensity of tornadoes and hail, given that they occur, tends to be almost entirely a function of the shear and only weakly depends on the thermodynamics. Climate model simulations suggest that CAPE will increase in the future and the wind shear will decrease. Detailed analysis has suggested that the CAPE change will lead to more frequent environments favorable for severe thunderstorms, but the strong dependence on shear for tornadoes, particularly the strongest ones, and hail means that the interpretation of how individual hazards will change is open to question. The recent development of techniques to use higher-resolution models to estimate the occurrence of storms of various kinds is discussed. Given the large interannual variability in environments and occurrence of events, caution is urged in interpreting the observational record as evidence of climate change.

12 citations

Journal ArticleDOI
TL;DR: In this article, an ensemble of 130 idealized cloud-resolving simulations by simultaneously perturbing six atmospheric and four surface parameters describing the initial conditions was used to identify the key parameters impacting the inland characteristics and the intensity of the sea breeze convection in a tropical rainforest.
Abstract: Sea breeze fronts propagate inland from the coastline, driving convective initiation and aerosol redistribution. Forecasting sea breezes is challenging due to uncertainties in the initial conditions, as well as the covariance and interaction of various meteorological and surface parameters. Using the Regional Atmospheric Modeling System coupled to an interactive land‐surface model, we conduct an ensemble of 130 idealized cloud‐resolving simulations by simultaneously perturbing six atmospheric and four surface parameters describing the initial conditions. To identify the key parameters impacting the inland characteristics and the intensity of the sea breeze convection in a tropical rainforest, we apply statistical emulation and variance‐based sensitivity analysis techniques. This study extends a previous study which explored the impacts of various parameters on sea breeze characteristics in arid environments devoid of moist convection. Wind speed is identified as the main contributor to the inland extent, similar to the arid environment study. However, the relative impacts of surface properties on the inland extent are less significant in the moist environment where land‐surface heating can be suppressed via moist convective processes and vegetation‐atmosphere interactions. Two sea breeze‐initiated convection regimes are also identified: shallow and deep. Over the shallow regime, where convective available potential energy is limited, the inversion layer strength is the primary control of the convective intensity. Over the deep regime, boundary layer temperature exerts a robust control over the convective available potential energy and hence the convective intensity. The potential vertical redistribution of aerosols is closely related to the convective intensity.

11 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the differences in convective activities in the tropical region (30°S −30°N, 180°E −180°W) during different phases of the quasi-biennial oscillation (QBO) using five metrics representing tropical convection: (i) precipitation and (ii) outgoing longwave radiation from observations and (iii) convective available potential energy (CAPE), (iv) deep convective heating rate, and (v, convective cloud top pressure from reanalysis data).
Abstract: Differences in convective activities in the tropical region (30°S–30°N, 180°E–180°W) during different phases of the quasi-biennial oscillation (QBO) are investigated over 32 years (1979–2010) using five metrics representing tropical convection: (i) precipitation and (ii) outgoing longwave radiation from observations and (iii) convective available potential energy (CAPE), (iv) deep convective heating rate, and (v) convective cloud top pressure from reanalysis data. The easterly (QBOE) and westerly (QBOW) phases of the QBO are defined using the zonal wind anomaly from the monthly climatology at 50 hPa. During the QBOE (QBOW), the convective activities are intensified (weakened) over the Maritime Continent and weakened (intensified) over the equatorial eastern and central Pacific. Therefore, the zonal mean values of the five metrics averaged over chronically convective regions show stronger convective activities during the QBOE than during the QBOW, while the opposite is true for the whole tropical region. Composite analyses are also performed during the neutral, El Nino, and La Nina periods. In the neutral period, the convective activities during QBOE are stronger than during QBOW except in the equatorial region (10°S–10°N). The convective activities over the Maritime Continent (central and eastern Pacific) are enhanced when La Nina and the QBOE (El Nino and the QBOW) occur simultaneously. All metrics show similar pattern to one another, implying that the metrics from reanalysis data represent the variations in the convective activities with respect to the QBO reasonably well. Among the five metrics, the CAPE is most sensitive to the QBO phase, likely because the virtual temperature in the upper troposphere is modulated by anomalous meridional circulations induced by different QBO phases.

11 citations


Network Information
Related Topics (5)
Climate model
22.2K papers, 1.1M citations
89% related
Stratosphere
15.7K papers, 586.6K citations
86% related
Monsoon
16K papers, 599.8K citations
85% related
Sea surface temperature
21.2K papers, 874.7K citations
84% related
Precipitation
32.8K papers, 990.4K citations
84% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202365
202291
202151
202038
201932
201827