Silvia M. Calderón

Silvia M. Calderón
Finnish Meteorological Institute · Kuopio Unit

PhD
Aerosol-stratocumulus cloud interactions using large eddy simulation

About

36
Publications
9,010
Reads
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309
Citations
Additional affiliations
February 2021 - present
Finnish Meteorological Institute
Position
  • Researcher
Description
  • Atmospheric modelling group. Large-eddy simulation of boundary layer clouds.
November 2018 - January 2021
University of Oulu
Position
  • Senior Researcher
Description
  • ATMOS Research Group, Nano and Molecular Systems Research Unit
March 1999 - present
University of the Andes
Position
  • Professor (Full)
Description
  • Full Professor at undergraduate and graduate levels in Thermodynamics, Physical Chemistry, Engineering Applied Mathematics and Environmental Sciences
Education
May 2002 - May 2006
University of South Florida
Field of study
  • Chemical Engineering
September 1999 - April 2002
University of the Andes
Field of study
  • Engineering Applied Mathematics
January 1992 - September 1998
University of the Andes
Field of study
  • Chemical Engineering

Publications

Publications (36)
Article
Full-text available
The response in cloud water content to changes in cloud condensation nuclei remains one of the major uncertainties in determining how aerosols can perturb cloud properties. In this study, we used an ensemble of large eddy simulations of marine stratocumulus clouds to investigate the correlation between cloud liquid water path (LWP) and the amount o...
Preprint
Full-text available
The response in cloud water content to changes in cloud condensation nuclei remains one of the major uncertainties in determining how aerosols can perturb cloud properties. In this study, we used an ensemble of large eddy simulations of marine stratocumulus clouds to investigate the correlation between cloud liquid water path and the amount of clou...
Article
Full-text available
Surfactants have been a focus of investigation in atmospheric sciences for decades due to their ability to modify the water uptake and cloud formation potential of aerosols. Surfactants adsorb at the surface and can decrease the surface tension of aqueous solutions. In microscopic aqueous droplets with finite amounts of solute, surface adsorption m...
Preprint
Full-text available
Surfactants have been a focus of investigation in atmospheric sciences for decades due to their ability to modify the water uptake and cloud formation potential of aerosols. Surfactants adsorb to the air–solution interface and can decrease the surface tension, while in microscopic aqueous droplets simultaneously depleting the droplet bulk. While th...
Article
Full-text available
We carried out a closure study of aerosol–cloud interactions during stratocumulus formation using a large eddy simulation model UCLALES–SALSA (University of California Los Angeles large eddy simulation model–sectional aerosol module for large applications) and observations from the 2020 cloud sampling campaign at Puijo SMEAR IV (Station for Measuri...
Article
Full-text available
Upon a new measurement technique, it is possible to sharpen the determination of microphysical properties of cloud droplets using high resolving power imaging. The shape, size, and position of each particle inside a well-defined, three-dimensional sample volume can be measured with holographic methods without assumptions of particle properties. In...
Preprint
Full-text available
We studied two cases of cloud formation, one diurnal (24 September 2020) and one nocturnal (31 October 2020), with high and low aerosol loadings, respectively. Aerosol number concentrations differ more than 1 order of magnitude between cases and therefore, lead to cloud droplet number concentration (CDNC) values which range from less than 100 cm-3...
Article
Full-text available
Surface active compounds (surfactants) are frequently found in atmospheric aerosols and droplets. As they adsorb to the surfaces of microscopic systems, surfactants can decrease aqueous surface tension and simultaneously deplete the bulk concentration. These processes may influence the activation of aerosols into cloud droplets and investigation of...
Preprint
Full-text available
Upon a new measurement technique, it is possible to sharpen the determination of microphysical properties of cloud droplets using high resolving power imaging. The shape, size, and position of each particle inside a well-defined, three-dimensional sample volume can be measured with holographic methods without assumptions of particle properties. In-...
Preprint
Full-text available
Surface active compounds (surfactants) found in atmospheric aerosols can decrease droplet surface tension as they adsorb to the droplet surfaces simultaneously depleting the droplet bulk. These processes may influence the activation properties of aerosols into cloud droplets and investigation of their role in cloud microphysics has been ongoing for...
Article
Full-text available
Surfactants exist in atmospheric aerosols mixed with inorganic salts and can significantly influence the formation of cloud droplets due to bulk–surface partitioning and surface tension depression. To model these processes, we need continuous parametrizations of the concentration dependent properties of aqueous surfactant–salt solutions for the ful...
Article
Full-text available
We introduce the CMC based Ionic Surfactant Activity model (CISA) to calculate activ- ity coefficients in ternary aqueous solutions of an ionic surfactant and an inorganic salt. The surfactant can be either anionic or cationic and in the present development, the surfactant and inorganic salts share a common counterion. CISA incorporates micellizati...
Article
Full-text available
Organosulfates make significant contributions to atmospheric secondary organic aerosol (SOA), but little is known about the thermodynamic properties of atmospherically relevant organosulfates. We have used the COSMOtherm program to calculate both the gas- and condensed-phase properties of previously identified atmospherically relevant monoterpene-...
Article
Full-text available
The fugacity and Gibbs Free Energy are thermodynamic properties to calculate the conditions of phase equilibria and chemical equilibria. Chemical engineering undergraduate students struggle to understand, estimate and use these properties to solve industrial problems. We propose a teaching methodology to introduce these concepts from their historic...
Article
Full-text available
The physical processes and time scales underlying the evolution of surface tension in atmospheric solution droplets are largely unaccounted for in present models describing cloud droplet formation. Adsorption of surface-active...
Preprint
Full-text available
Abstract. Organosulfates make significant contributions to atmospheric secondary organic aerosol (SOA), but little is still known about the thermodynamic properties of atmospherically relevant organosulfates. We have used the COSMO therm program to calculate both gas- and condensed-phase properties of previously identified atmospherically relevant...
Book
Full-text available
Esta obra compila un conjunto de experimentos cuidadosamente seleccionados y diseñados para estudiar los tópicos más importantes de la Fisicoquímica para Ingenieros Químicos. Cada trabajo experimental permite estudiar un tipo de equilibrio de fases, reacción química o proceso de transferencia de masa de interés industrial; y probar la validez de lo...
Chapter
Full-text available
La dosificación de reactivos en las plantas de tratamiento de agua por lo general resulta imprecisa, debido a diferentes factores que intervienen, como los modelos complejos de balances de materia, las variaciones en las condiciones climáticas y de operación, disponibilidad de reactivos y materias primas. Tal complejidad impide el uso de modelos co...
Article
Full-text available
This study presents a Parametric Dynamic Matrix Controller (PDMCr) to handle independently the process gain, time constant and dead time effects over the DMC performance. The controller is complemented with a fuzzy supervisory module that monitors changes on the process nonlinear behavior and keeps updated the embedded process model, saving time by...
Book
Full-text available
Este "Manual de Trabajo Experimental en Análisis Instrumental para Ingenieros" ha sido concebido para guiar el aprendizaje de las técnicas analíticas más importantes, a través de su aplicación para la solución de problemas de naturaleza ingenieril. Los experimentos han sido cuidadosamente seleccionados, y ordenados para avanzar en complejidad con l...
Article
Full-text available
First long-term observations of South American biomass burning aerosol within the tropical lower free troposphere are presented. The observations were conducted between 2007 and 2009 at a high altitude station (4765 m a.s.l.) on the Pico Espejo, Venezuela. Sub-micron particle volume, number concentrations of primary particles and particle absorptio...
Chapter
Full-text available
Formation and growth events of nucleation mode particles (10-25 nm in diameter) were analyzed from 27 month period of particle size distribution measurements at the high altitude site Pico Espejo in Venezuela. Particle formation was observed both in air masses connected to boundary layer air and in free tropospheric conditions. The frequency and ma...
Chapter
Full-text available
The long-term measurements of aerosol number and size distributions in tropical free troposphere (FT) were carried out from 2007 until 2009. The measurements took place at the high altitude Atmospheric Research Station Pico Espejo located on top of the Sierra Nevada mountain ridge at 4765 m a.s.l. nearby the city of Merida, Venezuela. Analysis of a...
Article
Full-text available
First long-term observations of South American biomass burning aerosol within the tropical lower free troposphere are presented. The observations were conducted between 2007 and 2009 at a high altitude station (4765 m a.s.l.) on the Pico Espejo, Venezuela. Sub-micron aerosol volume, number concentrations of primary particles and particle absorption...
Article
Full-text available
The acid wet deposition flux for an urban site at high altitude in La Hechicera, Venezuela, is presented using 24-hr rainwater samples collected on a wet-only monitor and was analyzed according to the guidelines suggested by the Global Atmospheric Watch Precipitation Chemistry Program (World Meteorological Organization). To assess the inter-annual...
Article
Full-text available
The first long-term measurements of aerosol number and size distributions in South-American tropical free troposphere (FT) were performed from March 2007 until March 2009. The measurements took place at the high altitude Atmospheric Research Station Alexander von Humboldt. The station is located on top of the Sierra Nevada mountain ridge at 4765 m...
Article
Full-text available
The first long-term measurements of aerosol number and size distributions in South-American tropical free troposphere were performed from March 2007 until Mai 2009. The measurements took place at the high altitude Atmospheric Research Station Alexander von Humboldt. The station is located on top of the Sierra Nevada mountain ridge at 4765 m a.s.l....
Article
Full-text available
Since March 2004 the ground-based 268–280 GHz radiometer MIRA 2 has been in quasi-continuous operation at the inner-tropical Mérida Atmospheric Research Station (MARS) on Pico Espejo (8.58°N, 71.15°W, 4765 m above sea level) in the Venezuelan Andes. Using the optimal estimation method concentration profiles of ozone have been retrieved in the strat...
Article
Full-text available
Hourly-measured gas concentrations and 24-h integrated PM10 concentrations were used in conjunction with a below-cloud scavenging model to explain nitrate (NO3−) concentrations in rainwater samples collected at a bayside monitoring site in Tampa, Florida, USA. Mass particle concentrations were assumed to have a log-normal distribution as a function...
Article
Full-text available
Resumen Se analizaron estadísticamente los patrones de variación de los promedios anuales, diarios y horarios de la concentración de ozono (O3) medida entre los años 2005-2007 en la Estación de Investigación Atmosférica “Alejandro de Humboldt” (EIAADH) en los Andes Venezolanos, con el objetivo de encontrar diferencias significativas con respecto a...
Article
Full-text available
We estimated the wet deposition flux of dissolved organic nitrogen (DON) to Tampa Bay, Florida, using 24-h integrated aerosol and rainwater samples collected simultaneously on days with rainfall between July and September 2005. In rainwater, dissolved inorganic nitrogen (DIN) and DON average concentrations were 54.7±44.0 and 4.7±2.7 μM-N, respectiv...
Article
Full-text available
The research objective was to adapt the ultraviolet (UV)-photolysis method to determine dissolved organic nitrogen (DON) in aqueous extracts of aerosol samples. DON was assumed to be the difference in total concentration of inorganic nitrogen forms before and after sample irradiation. Using a 2(2) factorial design the authors found that the optimal...
Article
Full-text available
ABSTRACT: Atmospheric deposition of nitrogen species represents an additional nutrient source to natural environments, and can alter the nitrogen cycle by increasing nutrient levels beyond the requirements of organisms. In Tampa Bay, atmospheric deposition of dissolved inorganic nitrogen species (DIN) has been found to be the second largest nitroge...

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