Numerical simulations of tropical convective clouds over cuba using a one-dimensional and time-dependent cloud model

Alfonso, L.; Martı́nez, Daniel; Pérez, Carlos Aedo

doi:10.1016/s0169-8095(98)00036-2

Cited by 6 publications

(5 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…in Alfonso et al . (). In addition, it is also known that clouds associated with deep convection tend to be ‘top‐heavy’ due to the presence of the anvil, cirrus and other high‐level clouds.…”

Section: Model Experimentsmentioning

confidence: 97%

See 1 more Smart Citation

Subgrid‐scale cloud–radiation feedback for theBetts–Miller–Janjić convection scheme

Koh

Fonseca

2016

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

Cloud-radiation feedbacks play a crucial role in the climate system and continue to be a major source of uncertainty in global climate model projections. Despite its importance for regional and local circulations, these feedback processes are not included in subgrid-scale convective parametrizations used in regional weather and climate models, in particular in adjustment schemes that, as opposed to mass-flux schemes, do not deal with convective condensates. Here we present a cloud scheme developed for the Betts-Miller-Janjić (BMJ) cumulus scheme used in the Weather Research and Forecasting (WRF) model that is fully general and can easily be applied to any other convective scheme. We parametrize the convective cloud fraction as a function of the BMJ time-step precipitation rate with the vertical cloud profile given by a 'top-heavy' Poisson distribution, similar to observed profiles. The cloud condensates are defined based on the assumption that the mass of convective cloud per unit mass of water vapour in cloudy air is constant in the column. In this scheme there are two tunable parameters:δ, that determines the vertical structure of the convective cloud, and γ , that controls the amount of cloud mass. The performance of the scheme is evaluated in a 1-year run and WRF is found to give a much better representation of the observed cloudiness with smaller biases in the surface radiation fields with respect to observations and reanalysis.

show abstract

Section: Model Experimentsmentioning

confidence: 97%

“…Since the peak in a discrete Poisson distribution occurs at the integer just smaller than the mean value, to be consistent with observed top‐heavy profiles of tropical clouds (e.g. Alfonso et al ., ), we require

δ ≳ 2 ν = \frac{2 δ^{2}}{ψ^{2}} .

…”

Section: Precipitating Convective Cloud Schemementioning

confidence: 99%

Subgrid‐scale cloud–radiation feedback for theBetts–Miller–Janjić convection scheme

Koh

Fonseca

2016

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

show abstract

“…The radar and sounding data employed in this study were obtained during a field experiment. Several studies have been conducted on the experimental site in the Camaguey region (Koloskov et al, 1996;Alfonso et al, 1998;Martínez and Gori, 1999).…”

Section: Radar Descriptionmentioning

confidence: 99%

A numerical study of cell merger over Cuba – Part I: implementation of the ARPS/MM5 models

Pozo¹,

Borrajero²,

Marín³

et al. 2006

Ann. Geophys.

View full text Add to dashboard Cite

Abstract. On 21 July 2001 a number of severe storms developed over the region of Camaguey, Cuba, which were observed by radar. A numerical simulation was performed in order to realistically reproduce the development of the storms observed that day. The mesoscale model MM5 was used to determine the initial, boundary and update conditions for the storm-scale simulation with the model ARPS. Changes to the source code of ARPS were made in order to assimilate the output from the MM5 as input data and a new land-use file with a 1-km horizontal resolution for the Cuban territory was created.A case representing the merger between cells at different stages of development was correctly reproduced by the simulation and is in good agreement with radar observations. The state of development of each cell, the time when the merger occurred, starting from the formation of clouds, the propagation motion of the cells and the increase in precipitation, due to the growth of the area after the merger, were correctly reproduced. Simulated clouds matched the main characteristics of the observed radar echoes, though in some cases, reflectivity tops and horizontal areas were overestimated. Maximum reflectivity values and the heights where these maximum values were located were in good agreement with radar data, particularly when the model reflectivity was calculated without including the snow. The MM5/ARPS configuration introduced in this study, improved sensibly the ability to simulate convective systems, thereby enhancing the local forecasting of convection in the region.

show abstract

“…Dynamic equations for vertical air velocity, w; radial air velocity, u a ; temperature, T ; water vapor mixing ratio, Q v are described in detail in Alfonso et al (1998) and AR2002. We assumed for every variable A (Ogura and Takahashi, 1971) that…”

Section: Dynamicsmentioning

confidence: 99%

“…However, some sensitivity tests to prescribed cloud parameters (i.e. cloud radius) can be found in Alfonso et al (1998).…”

Section: Sensitivity To Ccn Compositionmentioning

confidence: 99%

The influence of organic compounds on the development of precipitation acidity in maritime clouds

Alfonso

Raga

2004

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. In order to estimate the anthropogenic influence of gas and aerosol emissions from the Petroleum Industry in maritime zones with clouds of small vertical extent, a numerical 1-D Eulerian cloud-chemical model with detailed microphysics (Alfonso and Raga, 2002) is used to simulate the influence of water soluble organic compounds (WSOC) and organic+inorganic gas emissions on cloud development. Following Mircea et al. (2002), we tested the sensitivity of the cloud and precipitation development in the classical inorganic case (CIC) and the inorganic+organic case (IOC) with respect to CCN compositions. The results indicate an increase in the droplet concentration for the IOC, and a delay in the development of precipitation.The pH spectral evolution was studied during both the development and precipitation stages. The influence of the diffusion of formic acid and its generation by oxidation of hydrated formaldehyde in the aqueous phase result in a reduction in the pH of precipitation in the range between 0.05 and 0.15 pH units (from 1 to 3%) for the high ambient SO 2 concentration (20 ppb) and between 0.2-0.5 pH units (from 4 to 10%) for the low ambient SO 2 concentration (1 ppb) case.

show abstract

Numerical simulations of tropical convective clouds over cuba using a one-dimensional and time-dependent cloud model

Cited by 6 publications

References 10 publications

Subgrid‐scale cloud–radiation feedback for theBetts–Miller–Janjić convection scheme

Subgrid‐scale cloud–radiation feedback for theBetts–Miller–Janjić convection scheme

A numerical study of cell merger over Cuba – Part I: implementation of the ARPS/MM5 models

The influence of organic compounds on the development of precipitation acidity in maritime clouds

Contact Info

Product

Resources

About