Ilan Koren
Dados Biográficos
| ID | 110683 |
|---|---|
| NOME | Ilan Koren |
| PRENOMES | Ilan |
| SOBRENOME | Koren |
| ASSINATURA | KOREN I |
| AFILIAÇÕES | Weizmann Institute of Science |
| ORCID | 0000-0001-6759-6265 |
| VERIFICADO | Sim |
| TOTAL DE OBRAS | 16 |
| TOTAL DE CITAÇÕES | 4 |
| TOTAL COMO AUTOR | 16 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 1993 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2025 |
| ÍNDICE H | 1 |
Tara Polaris
The central Arctic is experiencing warming up to four times faster than the global average. This Arctic amplification is accompanied by large deviations in climate projections, making anticipation of high-impact, near-term regional biodiversity and climate change difficult. Several atmospheric processes contribute simultaneously to Arctic amplification and biodiversity change yet remain largely unstudied, not least because of the difficulty to ac…
Influence of open ocean biogeochemistry on aerosol and clouds
Aerosols and clouds are key components of the marine atmosphere, impacting the Earth’s radiative budget with a net cooling effect over the industrial era that counterbalances greenhouse gas warming, yet with an uncertain amplitude. Here we report recent advances in our understanding of how open ocean aerosol sources are modulated by ocean biogeochemistry and how they, in turn, shape cloud coverage and properties. We organize these findings in suc…
Observation of aerosol induced ‘lower tropospheric cooling’ over Indian core monsoon region
Aerosols play a significant role in regional scale pollution that alters the cloud formation process, radiation budget, and climate. Here, using long-term (2003–2019) observations from multi-satellite and ground-based remote sensors, we show robust aerosol-induced instantaneous daytime lower tropospheric cooling during the pre-monsoon season over the Indian core monsoon region (ICMR). Quantitatively, an average cooling of −0.82 °C ± 0.11 °C to −1…
Ear infection prevalence in prehistoric and historic populations of the southern Levant
Studying infectious diseases in ancient times is of significant importance to our understanding of past populations' ways of life. Otitis media (OM) is beneficial for this purpose because it is frequent and influenced by environmental conditions. The aims of the current study were to create a reliable criterion for identifying OM in skeletal material, and to follow trends regarding the prevalence of OM throughout the terminal Pleistocene-Holocene…
Harnessing remote sensing to address critical science questions on ocean-atmosphere interactions
Earth observing systems have proven to be a unique source of long-term synoptic information on numerous physical, chemical and biological parameters on a global scale. Merging this information for integrated studies that peruse key questions about the ocean-atmosphere interface is, however, very challenging. Such studies require interdisciplinary frameworks and novel insights into ways to address the problem. We present here a perspective review …
Feedback mechanisms of shallow convective clouds in a warmer climate as demonstrated by changes in buoyancy
Cloud feedbacks could influence significantly the overall response of the climate system to global warming. Here we study the response of warm convective clouds to a uniform temperature change under constant relative humidity (RH) conditions. We show that an increase in temperature drives competing effects at the cloud scale: a reduction in the thermal buoyancy term and an increase in the humidity buoyancy term. Both effects are driven by the inc…
Global association of aerosol with flash density of intense lightning
A global scale study of the association between aerosol loading and lightning production was conducted, using a full year’s data for 2012 (as well as seasonal data) of the cloud-to-ground lightning record from the world wide lightning location network and aerosol optical depth measured by MODIS. 70% of all grid squares examined and 94% of the statistically significant ones had higher flash densities under polluted conditions than the clean ones. …
Enhanced humidity pockets originating in the mid boundary layer as a mechanism of cloud formation below the lifting condensation level
A ground-based field campaign was conducted during the summer of 2011, 10 km east of the Israeli coast, aimed at studying small, warm convective clouds. During the campaign, clouds were detected on days that were predicted to be cloud-free by standard forecasting methods. Moreover, the clouds’ bases were often much lower than the estimated lifting condensation level. Detailed air parcel model simulations revealed that such small non-buoyant cloud…
Aerosol effect on the mobility of cloud droplets
Cloud droplet mobility is referred to here as a measure of the droplets ability to move with ambient air. We claim that an important part of the aerosol effect on convective clouds is driven by changes in droplet mobility. We show that the mass-weighted average droplet terminal velocity, defined here as the effective terminal velocity (eta) and its spread (sigma_eta) serve as direct measures of this effect. Moreover, we develop analytical estimat…
On the properties and radiative effects of small convective clouds during the eastern Mediterranean summer
A ground-based field campaign was conducted over the summer of 2011 in Israel to measure the properties of small warm clouds. The horizontal size distribution for cloud sizes of 50–3000 m is presented, with a special focus on the properties of the smallest clouds (liquid water path <10 g m ^−2 , cloud thickness < ∼50 m) and their estimated radiative effect. We show that these small clouds dominate the cloud radiative properties during the summer …
On the signature of the cirrus twilight zone
Cirrus clouds are known to play a key role in the climate system, but their overall effect on Earth’s radiation budget is not yet fully quantified. The uncertainties are, in part, due to ambiguities in cirrus extent or coverage. Here we show that despite careful filtering of cloudy pixels, cirrus clouds have a clear statistical signature. This signature can be estimated by the proximity to detectable cirrus clouds. Such a residual signature can a…
Relative humidity and its effect on aerosol optical depth in the vicinity of convective clouds
The hygroscopic growth of aerosols is controlled by the relative humidity (RH) and changes the aerosols' physical and hence optical properties. Observational studies of aerosol–cloud interactions evaluate the aerosol concentration using optical parameters, such as the aerosol optical depth (AOD), which can be affected by aerosol humidification. In this study we evaluate the RH background and variance values, in the lower cloudy atmosphere, an add…
Estimating cloud field coverage using morphological analysis
The apparent cloud-free atmosphere in the vicinity of clouds ('the twilight zone') is often affected by undetectable weak signature clouds and humidified aerosols. It is suggested here to classify the atmosphere into two classes: cloud fields, and cloud-free (away from a cloud field), while detectable clouds are included in the cloud field class as a subset. Since the definition of cloud fields is ambiguous, a robust cloud field masking algorithm…
Cloud–rain interactions
The effect of aerosol on clouds and precipitation poses one of the largest uncertainties in the estimation of the anthropogenic contribution to climate change. Often the local effect of aerosol on the radiation field both directly and indirectly by changing cloud properties can be more than an order of magnitude larger than the effect of greenhouse gases. Recent works also suggest that some of the local aerosol effects such as the heating of the …
The Bodélé depression
About 40 million tons of dust are transported annually from the Sahara to the Amazon basin. Saharan dust has been proposed to be the main mineral source that fertilizes the Amazon basin, generating a dependence of the health and productivity of the rain forest on dust supply from the Sahara. Here we show that about half of the annual dust supply to the Amazon basin is emitted from a single source: the Bodélé depression located northeast of Lake C…
Coping with the Gulf war
Ear infection prevalence in prehistoric and historic populations of the southern Levant
Studying infectious diseases in ancient times is of significant importance to our understanding of past populations' ways of life. Otitis media (OM) is beneficial for this purpose because it is frequent and influenced by environmental conditions. The aims of the current study were to create a reliable criterion for identifying OM in skeletal material, and to follow trends regarding the prevalence of OM throughout the terminal Pleistocene-Holocene…
Coping with the Gulf war
Coping with the Gulf war
The Bodélé depression
About 40 million tons of dust are transported annually from the Sahara to the Amazon basin. Saharan dust has been proposed to be the main mineral source that fertilizes the Amazon basin, generating a dependence of the health and productivity of the rain forest on dust supply from the Sahara. Here we show that about half of the annual dust supply to the Amazon basin is emitted from a single source: the Bodélé depression located northeast of Lake C…
Cloud–rain interactions
The effect of aerosol on clouds and precipitation poses one of the largest uncertainties in the estimation of the anthropogenic contribution to climate change. Often the local effect of aerosol on the radiation field both directly and indirectly by changing cloud properties can be more than an order of magnitude larger than the effect of greenhouse gases. Recent works also suggest that some of the local aerosol effects such as the heating of the …
Estimating cloud field coverage using morphological analysis
The apparent cloud-free atmosphere in the vicinity of clouds ('the twilight zone') is often affected by undetectable weak signature clouds and humidified aerosols. It is suggested here to classify the atmosphere into two classes: cloud fields, and cloud-free (away from a cloud field), while detectable clouds are included in the cloud field class as a subset. Since the definition of cloud fields is ambiguous, a robust cloud field masking algorithm…
Relative humidity and its effect on aerosol optical depth in the vicinity of convective clouds
The hygroscopic growth of aerosols is controlled by the relative humidity (RH) and changes the aerosols' physical and hence optical properties. Observational studies of aerosol–cloud interactions evaluate the aerosol concentration using optical parameters, such as the aerosol optical depth (AOD), which can be affected by aerosol humidification. In this study we evaluate the RH background and variance values, in the lower cloudy atmosphere, an add…
On the signature of the cirrus twilight zone
Cirrus clouds are known to play a key role in the climate system, but their overall effect on Earth’s radiation budget is not yet fully quantified. The uncertainties are, in part, due to ambiguities in cirrus extent or coverage. Here we show that despite careful filtering of cloudy pixels, cirrus clouds have a clear statistical signature. This signature can be estimated by the proximity to detectable cirrus clouds. Such a residual signature can a…
Aerosol effect on the mobility of cloud droplets
Cloud droplet mobility is referred to here as a measure of the droplets ability to move with ambient air. We claim that an important part of the aerosol effect on convective clouds is driven by changes in droplet mobility. We show that the mass-weighted average droplet terminal velocity, defined here as the effective terminal velocity (eta) and its spread (sigma_eta) serve as direct measures of this effect. Moreover, we develop analytical estimat…
On the properties and radiative effects of small convective clouds during the eastern Mediterranean summer
A ground-based field campaign was conducted over the summer of 2011 in Israel to measure the properties of small warm clouds. The horizontal size distribution for cloud sizes of 50–3000 m is presented, with a special focus on the properties of the smallest clouds (liquid water path <10 g m ^−2 , cloud thickness < ∼50 m) and their estimated radiative effect. We show that these small clouds dominate the cloud radiative properties during the summer …
Global association of aerosol with flash density of intense lightning
A global scale study of the association between aerosol loading and lightning production was conducted, using a full year’s data for 2012 (as well as seasonal data) of the cloud-to-ground lightning record from the world wide lightning location network and aerosol optical depth measured by MODIS. 70% of all grid squares examined and 94% of the statistically significant ones had higher flash densities under polluted conditions than the clean ones. …
Enhanced humidity pockets originating in the mid boundary layer as a mechanism of cloud formation below the lifting condensation level
A ground-based field campaign was conducted during the summer of 2011, 10 km east of the Israeli coast, aimed at studying small, warm convective clouds. During the campaign, clouds were detected on days that were predicted to be cloud-free by standard forecasting methods. Moreover, the clouds’ bases were often much lower than the estimated lifting condensation level. Detailed air parcel model simulations revealed that such small non-buoyant cloud…
Harnessing remote sensing to address critical science questions on ocean-atmosphere interactions
Earth observing systems have proven to be a unique source of long-term synoptic information on numerous physical, chemical and biological parameters on a global scale. Merging this information for integrated studies that peruse key questions about the ocean-atmosphere interface is, however, very challenging. Such studies require interdisciplinary frameworks and novel insights into ways to address the problem. We present here a perspective review …
Feedback mechanisms of shallow convective clouds in a warmer climate as demonstrated by changes in buoyancy
Cloud feedbacks could influence significantly the overall response of the climate system to global warming. Here we study the response of warm convective clouds to a uniform temperature change under constant relative humidity (RH) conditions. We show that an increase in temperature drives competing effects at the cloud scale: a reduction in the thermal buoyancy term and an increase in the humidity buoyancy term. Both effects are driven by the inc…
Ear infection prevalence in prehistoric and historic populations of the southern Levant
Studying infectious diseases in ancient times is of significant importance to our understanding of past populations' ways of life. Otitis media (OM) is beneficial for this purpose because it is frequent and influenced by environmental conditions. The aims of the current study were to create a reliable criterion for identifying OM in skeletal material, and to follow trends regarding the prevalence of OM throughout the terminal Pleistocene-Holocene…
Observation of aerosol induced ‘lower tropospheric cooling’ over Indian core monsoon region
Aerosols play a significant role in regional scale pollution that alters the cloud formation process, radiation budget, and climate. Here, using long-term (2003–2019) observations from multi-satellite and ground-based remote sensors, we show robust aerosol-induced instantaneous daytime lower tropospheric cooling during the pre-monsoon season over the Indian core monsoon region (ICMR). Quantitatively, an average cooling of −0.82 °C ± 0.11 °C to −1…
Influence of open ocean biogeochemistry on aerosol and clouds
Aerosols and clouds are key components of the marine atmosphere, impacting the Earth’s radiative budget with a net cooling effect over the industrial era that counterbalances greenhouse gas warming, yet with an uncertain amplitude. Here we report recent advances in our understanding of how open ocean aerosol sources are modulated by ocean biogeochemistry and how they, in turn, shape cloud coverage and properties. We organize these findings in suc…
Tara Polaris
The central Arctic is experiencing warming up to four times faster than the global average. This Arctic amplification is accompanied by large deviations in climate projections, making anticipation of high-impact, near-term regional biodiversity and climate change difficult. Several atmospheric processes contribute simultaneously to Arctic amplification and biodiversity change yet remain largely unstudied, not least because of the difficulty to ac…
Atmospheric aerosols and clouds (13 obras) · Environmental Science (13 obras) · Meteorology (13 obras) · Atmospheric sciences (12 obras) · Geology (12 obras) · Aerosol (10 obras) · Atmospheric chemistry and aerosols (10 obras) · Physics (9 obras) · Cloud computing (7 obras) · Geography (7 obras)