Orit Altaratz

Biographic Data

ID7992162
NAMEOrit Altaratz
GIVEN NAMESOrit
FAMILY NAMEAltaratz
SIGNATUREALTARATZ O
AFFILIATIONSWeizmann Institute of Science
ORCID0000-0002-7923-9000
VERIFIEDYes
TOTAL WORKS8
TOTAL CITATIONS0
AUTHOR COUNT8
EDITOR COUNT0
FIRST PUBLICATION YEAR2010
LATEST PUBLICATION YEAR2018
H-INDEX0

  • Feedback mechanisms of shallow convective clouds in a warmer climate as demonstrated by changes in buoyancy

    Open AccessGuy Dagan, Ilan Koren et al.ARTICLEEnvironmental Research Letters2018

    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

    Open AccessOrit Altaratz, Beata Kucienska et al.ARTICLEEnvironmental Research Letters2017

    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

    Open AccessE Hirsch, Ilan Koren et al.ARTICLEEnvironmental Research Letters2017

    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

    Open AccessIlan Koren, Orit Altaratz et al.ARTICLEEnvironmental Research Letters2015

    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

    Open AccessE Hirsch, Ilan Koren et al.ARTICLEEnvironmental Research Letters2015

    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

    Open AccessUri Wollner, Ilan Koren et al.ARTICLEEnvironmental Research Letters2014

    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

    Open AccessOrit Altaratz, R Z Bar-Or et al.ARTICLEEnvironmental Research Letters2013

    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

    Open AccessR Z Bar-Or, Ilan Koren et al.ARTICLEEnvironmental Research Letters2010

    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…