Carynelisa Haspel

Carynelisa Haspel
Hebrew University of Jerusalem | HUJI · Fredy and Nadine Herrmann Institute of Earth Sciences

PhD

About

70
Publications
12,678
Reads
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1,872
Citations
Citations since 2017
16 Research Items
618 Citations
2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140

Publications

Publications (70)
Article
We present a method for calculating multiple scattering of electromagnetic radiation by a collection of sparsely spaced spherical scatterers (SSSS) of Mie-scattering size based on first principles rather than radiative transfer theory. In this respect, our methodology is conceptually similar to the superposition T -matrix method. However, our imple...
Article
We present a formulation for calculating the electric field from the ground to the lower boundary of the ionosphere that is based on an analytical solution to Poisson's equation in three dimensions, combined with a numerical solution to the equation of charge continuity/conservation. This formulation allows one to follow the spatial and temporal ev...
Conference Paper
In order to reduce computational resources, we investigate the effect of limiting the dipole interaction range within a DDA calculation of light scattering. The results indicate that ignoring long-range interaction can be a good approximation.
Article
In this study, we examine the single-scattering properties of aggregates of nano-sized spherical scattering centers (spherules) of different sizes and refractive indices, with an emphasis on contrasting the single-scattering properties of ordered and disordered aggregates, holding all other parameters constant. The ordered aggregates are constructe...
Article
The progression of secondary waves emanating from scattering centers within a non-absorbing material in the visible part of the electromagnetic spectrum (wavelength 0.500 µm) is traced using two modeling schemes: the scattering order formulation (SOF) of the discrete dipole approximation (the original SOF) and the SOF with the Twersky approximation...
Conference Paper
The optical properties of atmospheric aerosol particles comprised of amorphous materials are modeled using two approaches, the Bruggeman effective medium approximation and an ideal amorphous solid model combined with a multiple-sphere T -matrix model.
Article
Full-text available
Previous studies have shown that the Lorentz-Lorenz relationship, or molar refractivity/specific refractivity effective medium approximation, enables a reasonable prediction of the refractive index of amorphous water ice, given the refractive index of crystalline water ice. In the current study, we show that the Bruggeman effective medium approxima...
Article
We present a simple, efficient, and flexible three-dimensional electrostatic model for calculating the magnitude and direction of the electric field from the ground to the base of the ionosphere for a given thunderstorm charge configuration, with the aim of evaluating the possibility for sprite inception. The model is based on a method-of-images so...
Article
The influence of hydrosol nonsphericity on the polarization characteristics of light under water is investigated by combining accurate single-scattering models for randomly oriented spheroidal scatterers with a radiative transfer model that employs Stokes formalism and considers refraction of direct unpolarized solar radiation and 100% linearly pol...
Article
Full-text available
The influence of internal inhomogeneities within hydrosol particles on the polarization characteristics of light is investigated by combining an accurate coated sphere (core-shell) single-scattering model with a radiative transfer model that employs Stokes formalism and considers refraction of direct solar radiation at the air–water interface follo...
Article
Full-text available
The influence of internal inhomogeneities within hydrosol particles on the polarization characteristics of light is investigated by combining an accurate coated sphere (core-shell) single-scattering model with a radiative transfer model that employs Stokes formalism and considers refraction of direct solar radiation at the air-water interface follo...
Article
Full-text available
Light polarization characteristics, i. e., degree of linear polarization (DoLP) and angle of linear polarization (AoLP), were documented in the depth of the littoral cave system of Rosh HaNikra on the northern Mediterranean shore of Israel (33° 5′ 35.24″ N, 35° 6′ 17.16″ E), based on light intensity sampled through polarizing filters at different h...
Conference Paper
The influence of internal inhomogeneities within hydrosol particles on the characteristics of the underwater light polarization pattern is investigated by combining an accurate coated sphere (core-shell) single scattering model with a radiative transfer model that employs Stokes formalism and considers refraction of direct solar radiation at the ai...
Article
In this study, we performed a series of sensitivity tests in order to elucidate the convergence tendency of the scattering order formulation (SOF) of the discrete dipole approximation (DDA). Using both the original formulation of the SOF and a new marching SOF, the progression of orders of scattering marches, along with the propagation of the incid...
Article
Full-text available
In the current study, the electromagnetic properties of porous aerosol particles are calculated in two ways. In the first, a porous target input file is generated by carving out voids in an otherwise homogeneous particle, and the discrete dipole approximation (DDA) is used to compute the extinction efficiency of the particle assuming that the voids...
Article
Full-text available
The urbanization of the shores of the Gulf of Aqaba has exposed the marine environment there, including unique fringing coral reefs, to strong anthropogenic light sources. Here we present the first in situ measurements of artificial nighttime light under water in such an ecosystem, with irradiance measured in 12 wavelength bands, at 19 measurement...
Article
Full-text available
The behavior of the particle size distribution (PSD) during the preparation of sol–gel silica-based antireflective coatings (ARCs) by dip coating was examined. It was found that the PSD after deposition differs dramatically from the PSD in the sol–gel suspensions, with the PSD after deposition being much narrower. A correlation between a decrease i...
Article
Superposed epoch analysis of meteorological reanalysis data is used to demonstrate a significant connection between intraseasonal solar variability and temperatures in the stratosphere. Decreasing solar flux leads to a cooling of the tropical upper stratosphere above 7 hPa, while increasing solar flux leads to a warming of the tropical upper strato...
Article
The relationship between the refractive index and the porosity of silica based anti-reflective coatings (ARCs) has been studied. The coatings were prepared with the traditional Stöber method. The refractive index was evaluated by fitting vis–NIR transmittance spectra to Fresnel׳s coefficient of reflection using the transfer matrix method. The poros...
Article
Full-text available
Porous glassy particles are a potentially significant but unexplored component of atmospheric aerosol that can form by aerosol processing through the ice phase of high convective clouds. The optical properties of porous glassy aerosols formed from a freeze-dry cycle simulating freezing and sublimation of ice particles were measured using a cavity r...
Article
Full-text available
Significance Aerosols cycling through clouds affect particle morphological and chemical properties, thus modifying aerosol effects on cloud microphysics and climate. Previous studies have focused on aerosol processing in warm clouds via aqueous-phase reactions. Here we investigate the physical modifications of aerosols following processing within i...
Article
We present results from a simple 2D model of the mesospheric electric field for several thunderstorm charge configurations. The model assumes a simple dipole structure with a screening charge above cloud-top. The charge centers are modeled as horizontal disks with a Gaussian charge density distribution. We solve the Poisson equation numerically, us...
Article
Full-text available
A full Mie scattering subroutine is employed to calculate what we call the linear polarization phase function (LPPF; percent polarization and e-vector orientation of radiation as a function of scattering angle) that results from refraction of the direct solar beam from air into water followed by single scattering by spherical hydrosols. The separat...
Article
Full-text available
Efficient visual pest control is still in its infant stages. Although being non-invasive, environmentally friendly and potentially cost effective, we still have not cracked the way to efficiently use it against epidemic vector-carrying and crop-infesting insects. Chironomid ovipostion can provide insights to key factors in visual pest control by in...
Article
Full-text available
Pollutants from global sources are known to affect the Eastern Mediterranean Shore (EMS). However, there has been no previous study explicitly locating the European sources, characterizing their transport pathways, and quantifying their contribution to local concentrations in the EMS. In the current study, spatially tagged carbon monoxide was used...
Article
Full-text available
Calculations of the radiative properties of hydrated ammonium sulfate (AS) aerosols often employ the conventional volume mixing rule, in which the refractive indices of AS and water are linearly averaged, weighted by their respective volume fractions in solution, and the real part of the refractive index of pure AS is taken to be 1.52-1.55, based o...
Article
Simultaneously retrieving the complex refractive indices of the core and shell of coated aerosol particles given the measured extinction efficiency as a function of particle dimensions (core diameter and coated diameter) is much more difficult than retrieving the complex refractive index of homogeneous aerosol particles. Not only must the minimizat...
Article
Full-text available
Aerosol-cloud interactions, such as aerosol loading in convective clouds resulting in either precipitation suppression or cloud invigoration, in higher cloud tops, and in longer-lived clouds, are well known. Here we investigate a new aerosol-cloud interaction, the effect of aerosol loading on Bénard cells, on the stratocumulus cloud fraction, and u...
Article
Full-text available
Knowledge of density-dependent processes and how they are mediated by environmental factors is critically important for understanding population and community ecology of insects, as well as for mitigating harmful insect-borne diseases. Here, we tested whether the oviposition of chironomids (Diptera: Chironomidae; non-biting midges), known to carry...
Article
Full-text available
Certain terrestrial animals use sky polarization for navigation. Certain aquatic species have also been shown to orient according to a polarization stimulus, but the correlation between underwater polarization and Sun position and hence the ability to use underwater polarization as a compass for navigation is still under debate. To examine this iss...
Article
Full-text available
European pollutants are known to affect the Eastern Mediterranean (EM). However, there has been no previous study explicitly locating the European sources, characterizing their transport pathways, and quantifying their contribution to local concentrations in the EM. In the current study, spatially tagged carbon monoxide was used as a tracer for pol...
Article
Full-text available
Atmospheric aerosols scatter and absorb solar radiation leading to variable effects on Earth's radiative balance. Aerosols individually comprising mixtures of different components ("internally mixed") interact differently with light than mixtures of aerosols, each comprising a different single component ("externally mixed"), even if the relative fr...
Article
Zonally propagating wave solutions of the linearized shallow water equations (LSWE) in a zonal channel on the rotating spherical earth are constructed from numerical solutions of eigenvalue equations that yield the meridional variation of the waves’ amplitudes and the phase speeds of these waves. An approximate Schrödinger equation, whose potential...
Article
Full-text available
Zonally propagating wave solutions of the linearized shallow water equations (LSWE) in a zonal channel on the rotating spherical earth are constructed from numerical solutions of eigenvalue equations that yield the meridional variation of the waves’ amplitudes and the phase speeds of these waves. An approximate Schrodinger equation, whose potential...
Article
We report synchronized optical observations of sprites in Israel during the winters of 2006/7–2007/8. Based on several events, we suggest that the elements of columniform sprites are organized in spaced intervals on the circumference of a circle centered directly above, or a little offset, to the vertical direction from the parent lightning. In 2D...
Article
Full-text available
This study focuses on the retrieval of the normalized mass absorption cross section (MAC) of soot using theoretical calculations that incorporate new measurements of the optical properties of organic carbon (OC) intrinsic to fresh diesel soot. Intrinsic OC was extracted by water and an organic solvent, and the complex refractive index of the extrac...
Article
Full-text available
Chironomids (Diptera: Chironomidae; non-biting midges) are known to be carriers of the Vibrio cholerae bacterium, responsible for the fatal cholera disease in humans. It was recently discovered that chironomid females choose their oviposition site by a visual cue. In this study, we test the hypothesis that this visual cue is the linear polarization...
Article
In this work, the possible climate effects of variations in dust flux during the last six glacial cycles (575–0 ka before present (BP)) are investigated. While most past studies investigated the role of dust in equilibrium or in relatively short transient experiments, in the present study, we conduct million-year simulations using a two-dimensional...
Article
Full-text available
Since as early as 1969, solar absorbing aerosols inside of cloud drops have been suggested to influence cloud radiative properties. The absorbing aerosols were invoked to help explain two "anomalies": 1) the maximum visible albedo of thick stratocumulus clouds is observed to be only 0.7-0.8, rather than Close to 1.0 as would be expected from pure w...
Article
Full-text available
Atmospheric aerosols absorb and reflect solar radiation causing surface cooling and heating of the atmosphere. The interaction between aerosols and radiation depends on their complex index of refraction, which is related to the particles' chemical composition. The contribution of light absorbing organic compounds, such as HUmic-LIke Substances (HUL...
Article
Full-text available
In this study, we measure the extinction efficiency at 532 nm of absorbing aerosol particles coated with a non-absorbing solid and liquid organic shell with coating thickness varying between 5 and 100 nm using cavity ring down aerosol spectrometry. For this purpose, we use nigrosin, an organic black dye, as a model absorbing core and two non–absorb...
Article
Using a scaling that allows us to separate the effects of the gravity wave speed from those of boundary location, we reduce the equations for linear waves in a zonal channel on the equatorial beta-plane to a single-parameter eigenvalue problem of the Schrödinger type with parabolic potential. The single parameter can be written δ = (Δϕ)2/α1/2, wher...
Article
Full-text available
Application of cavity ring down (CRD) spectrometry for measuring the optical properties of pure and mixed laboratory-generated aerosols is presented. The extinction coefficient (α<sub>ext</sub>), extinction cross section (σ<sub>ext</sub>) and extinction efficiency (Q<sub>ext</sub>) were measured for polystyrene spheres (PSS), ammonium sulphate ((NH...
Article
The role of biomass burning aerosols in the climate system is still poorly quantified, in part due to uncertainties regarding the optical properties of elemental and organic carbon (EC and OC, respectively), the main constituents of pyrogenic aerosols. In this study, we utilize comprehensive physical and chemical field measurements of biomass burni...
Chapter
Full-text available
Aerosol particles affect climate directly and indirectly. The direct climatic effect is via scattering and absorption of radiation and the indirect effect is mostly by affecting the properties of clouds and precipitation. These climatic effects impose one of the largest uncertainties in our understanding of the climate system. Recent studies have s...
Article
Application of cavity ring down (CRD) spectrometry for measuring the optical properties of pure and mixed laboratory-generated aerosols is presented. The extinction coefficient (αext), extinction cross section (σext) and extinction efficiency (Qext) were measured for polystyrene spheres (PSS), ammonium sulphate ((NH4)2(SO4)), sodium chloride (NaCl)...
Article
Full-text available
The largest uncertainty in the radiative forcing of climate change over the industrial era is that due to aerosols, a substantial fraction of which is the uncertainty associated with scattering and absorption of shortwave (solar) radiation by anthropogenic aerosols in cloud-free conditions (IPCC, 2001). Quantifying and reducing the uncertainty in a...
Article
Full-text available
In this study we perform an idealized experiment to investigate the effect of solar absorption in clouds on climate using a general circulation model with prescribed sea surface temperatures, focusing on the manner of regional changes during the northern summer season. The response arising from this type of perturbation is akin to ``semidirect'' ef...
Article
Full-text available
In this study the range of visible refractive indices and single-scattering albedos that can be obtained using various mean field formulations for mixtures of two components, where one component absorbs in the visible, is explored. For calculations of global radiative forcing and climate response, such formulations provide a convenient way to take...
Article
In this study, a Lagrangian adiabatic parcel model and a trajectory ensemble model (TEM) are used in a sequence of experiments to investigate effects of velocity fluctuations on drop spectrum broadening in stratocumulus clouds. Using the adiabatic parcel model, it is found that even with a weakly buoyant temperature profile, if the initial updraft...
Article
Full-text available
Abstract The underwater light field, which is nearly permanently and ubiquitously partially polarized, offers polarization sensitive animals special cues for mediatingva riousvisu alta sks. For the last fifty years, underwater polarization patterns have been studied with respect to their origin and their dependence on the optical properties of the...
Article
Full-text available
Previous radiative-convective model studies of the radiative forcing due to absorbing aerosols such as soot and dust have revealed a strong dependence on the vertical distribution of the absorbers. In this study, we extend this concept to absorption in cloud layers, using a one-dimensional radiative-convective model employing high, middle, and low...
Article
The effect of absorbing aerosols on clouds is investigated using a sequence of models. A size- and composition-resolved microphysical parcel model is used to look at the extent to which absorbing material from a continental air mass (dust, black carbon, and organic carbon) inside of cloud drops influences the amount of solar radiation absorbed by a...
Article
Full-text available
An important item to distinguish in estimations of cloud forcing is the characteristics of the ``clear sky.'' In this study we investigate the influence of the composition of the clear sky in calculations of shortwave cloud forcing based on two case studies from the Monterey Area Ship Track Experiment (MAST). The forcing is calculated with respect...
Article
The mechanism of droplet spectrum formation in cumulus clouds is studied using a microphysical air parcel model with a detailed description of diffusional growth of aerosol particles (AP) and cloud droplets. The model allows simulation of the development of wide bimodal droplet size spectra due to in-cloud nucleation of new droplets on aerosol part...
Article
Full-text available
A Lagrangian adiabatic parcel model and a trajectory ensemble model (TEM) are used in a sequence of experiments to investigate spectral broadening in stratocumulus clouds. Using the adiabatic parcel model, two mechanisms are shown to produce spec- tral broadening: 1) in-cloud nucleation of unactivated aerosol particles, as a result of strong increa...
Article
We use a size- and composition-resolved externally mixed aerosol microphysical model and a delta-Eddington exponential-sum-fit radiation algorithm to examine the interactions between aerosol particles and cloud drops, and their influence on solar radiation. Both the aerosol model and the radiation code are designed to explicitly handle external and...
Article
During the Aerosol Characterization Experiment (ACE-2), filter samples were collected aboard the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Pelican aircraft near Tenerife in June and July of 1997. The flights included constant altitude measurements in the boundary layer as well as profiles up to 3800 m providing detaile...
Article
Full-text available
During the Aerosol Characterization Experiment (ACE-2), filter samples were collected aboard the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Pelican aircraft near Tenerife in June and July of 1997. The flights included constant altitude measurements in the boundary layer as well as profiles up to 3800 m providing detaile...
Article
Full-text available
This study considers the effects of aerosols in cloudy atmospheres on the wavelength dependence of atmospheric transmission in the ultraviolet and visible parts of the solar spectrum. Normalizing the transmission to that of a cloud- and aerosol-free atmosphere, we examine the competing influences of clouds and aerosols on the shape of the transmiss...
Article
In this study we model the effects of continental and urban aerosols and their variation with humidity on the transmission of ultraviolet and visible radiation to the Earth's surface. Normalizing the transmission to that of an aerosol-free atmosphere, we examine the mechanisms behind two wavelength-dependent aerosol effects. The first is a dip in t...
Article
Full-text available
We offer some remarks on the greenhouse effect due to high clouds which reflect thermal infrared radiation, but do not absorb or emit it. Such clouds are an idealization of the CO 2 -ice clouds which are thought to have existed early in the history of Mars. Clouds of this type enter also in the ability of the Earth to recover from a globally glacia...
Article
Full-text available
Measurements of the ground-level solar irradiance from Palmer Station, Antarctica, and Ushuaia, Argentina, reveal a systematic wavelength dependence in the attenuation provided by cloudy skies. As wavelength increases from 350 to 600 nm, the measured cloudy-sky irradiance, expressed as a fraction of the clear-sky value, decreases. Results from Ushu...
Article
In this study we used Mie scattering subroutines combined with a 'single-scattering-separate' delta-Eddington model to examine the effects of clouds, aerosols, and gaseous absorbers on atmospheric transmission in the ultraviolet and visible parts of the solar spectrum. Our results show that the ways in which clouds and aerosols affect atmospheric t...
Article
Abstract— Information on column ozone and the earth's reflectivity obtained from satellite-based data allows estimates of the long-term behavior in erythemal irradiance at any location, including the attenuation provided by clouds. Year-to-year changes in cloudiness over specific geographic regions make a major contribution to interannual variabili...
Article
In this study we model the effects of continental and urban aerosols and their variation with humidity on the transmission of ultraviolet and visible radiation to the Earth's surface. Normalizing the transmission to that of an aerosol- free atmosphere, we examine the mechanisms behind two wavelength-dependent aerosol effects. The first is a dip in...

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Project (1)
Project
Abstract Light pollution (LP) is widely spread around the globe. It includes illumination of cities, gas and oil platforms off-shore, piers and fires. Although the effect of light pollution on the skylight is largely addressed, the level of its penetration of into the marine environment and its effect on marine animal vision and their distribution has been poorly investigated. The proposed research objectives are to: (i) describe the light field in LP waters, (ii) investigate the effect of LP on the animal community structure at various taxonomic levels, (iii) describe the effect of LP on marine animal vision, (iv) check for photosynthesis of phytoplankton in LP waters and (v) to suggest key parameters for future development and use of non-polluting light sources. In-situ measurements will be conducted at LP and non-LP stations in the Mediterranean sea and the Gulf of Aqaba, Eilat using various submersible radiometers to measure multispectral radiance and polarization, which will be compared with radiative transfer computer codes specifically designed for scattering waters containing varied scatterer sizes and shapes. Species abundance and richness will be measured by ship and seine net trawling and by SCUBA diving transects, and Flow cytometer. Animal vision will be checked behaviorally using optomotor response techniques, and by microscopy of the retina and its photoreceptor structure. Photosynthesis efficiency will be checked in-situ using 14C uptake technique and in the laboratory by a novel newly designed OxyPAM system. The research groups will strongly cooperate with exchange of measured radiation data implemented into the model, and photosynthesis efficiency and in-situ phytoplankton distribution that will be correlated with zooplankton distribution analysis. The research will provide novel information regarding the amount of LP penetrating the ocean and how the marine ecosystem and animal vision are affected by it. Vision-based key parameters for non-polluting light sources will be defined.