scholarly journals Aerosols Make Cumulus Clouds Brighter but Shorter Lived

Eos ◽  
2016 ◽  
Vol 97 ◽  
Author(s):  
David Shultz
Keyword(s):  
Computer Simulations ◽  
Cloud Cover ◽  
Aerosol Particles ◽  
Cooling Effect ◽  
Cumulus Clouds

Computer simulations show that although adding aerosol particles to clouds can make them more reflective, the cooling effect from clouds is largely counterbalanced by a reduction in overall cloud cover.

A simplified model for the formation, movement, and dissipation of fair weather cumulus clouds

1965 ◽  
Vol 2 (1) ◽  
pp. 178-185
Author(s):  
Martin Fox
Keyword(s):  
Stochastic Model ◽  
Cloud Cover ◽  
Temporal Evolution ◽  
Cooling Effect ◽  
Simplified Model ◽  
Fair Weather ◽  
Cumulus Clouds ◽  
Solar Heat

Certain patches of ground are favorable to the formation of fair weather cumulus clouds. These are patches which reflect rather than absorb solar heat. As the air above these patches is warmed, it will rise and, if the humidity is sufficient, the cooling effect of higher elevation will cause formation of a cloud of the type known as the fair weather cumulus. This fact is used in the present paper to develop a stochastic model for the temporal evolution of the contribution to cloud cover by fair weather cumuli.

A simplified model for the formation, movement, and dissipation of fair weather cumulus clouds

1965 ◽  
Vol 2 (01) ◽  
pp. 178-185
Author(s):  
Martin Fox
Keyword(s):  
Stochastic Model ◽  
Cloud Cover ◽  
Temporal Evolution ◽  
Cooling Effect ◽  
Simplified Model ◽  
Fair Weather ◽  
Cumulus Clouds ◽  
Solar Heat

Certain patches of ground are favorable to the formation of fair weather cumulus clouds. These are patches which reflect rather than absorb solar heat. As the air above these patches is warmed, it will rise and, if the humidity is sufficient, the cooling effect of higher elevation will cause formation of a cloud of the type known as the fair weather cumulus. This fact is used in the present paper to develop a stochastic model for the temporal evolution of the contribution to cloud cover by fair weather cumuli.

scholarly journals A Simple Parameterization Coupling the Convective Daytime Boundary Layer and Fair-Weather Cumuli

2005 ◽  
Vol 62 (6) ◽  
pp. 1976-1988 ◽  
Author(s):  
Larry K. Berg ◽  
Roland B. Stull
Keyword(s):  
Boundary Layer ◽  
Cloud Cover ◽  
Potential Temperature ◽  
Joint Probability ◽  
Cloud Base ◽  
Cumulus Clouds ◽  
Eddy Simulation ◽  
Boundary Layer Cloud ◽  
Using Data ◽  
Water Vapor Mixing Ratio

Abstract A new parameterization for boundary layer cumulus clouds, called the cumulus potential (CuP) scheme, is introduced. This scheme uses joint probability density functions (JPDFs) of virtual potential temperature (θυ) and water-vapor mixing ratio (r), as well as the mean vertical profiles of θυ, to predict the amount and size distribution of boundary layer cloud cover. This model considers the diversity of air parcels over a heterogeneous surface, and recognizes that some parcels rise above their lifting condensation level to become cumulus, while other parcels might rise as noncloud updrafts. This model has several unique features: 1) cloud cover is determined from the boundary layer JPDF of θυ versus r, 2) clear and cloudy thermals are allowed to coexist at the same altitude, and 3) a range of cloud-base heights, cloud-top heights, and cloud thicknesses are predicted within any one cloud field, as observed. Using data from Boundary Layer Experiment 1996 and a model intercomparsion study using large eddy simulation (LES) based on Barbados Oceanographic and Meteorological Experiment (BOMEX), it is shown that the CuP model does a good job predicting cloud-base height and cloud-top height. The model also shows promise in predicting cloud cover, and is found to give better cloud-cover estimates than three other cumulus parameterizations: one based on relative humidity, a statistical scheme based on the saturation deficit, and a slab model.

scholarly journals Aerosol exposure versus aerosol cooling of climate: what is the total health outcome?

2010 ◽  
Vol 10 (6) ◽  
pp. 15055-15073
Author(s):  
J. Löndahl ◽  
E. Swietlicki ◽  
E. Lindgren ◽  
S. Loft
Keyword(s):  
Climate Change ◽  
Health Effects ◽  
Aerosol Particles ◽  
Health Effect ◽  
Health Benefit ◽  
Cooling Effect ◽  
Ship Emissions ◽  
Aerosol Emission ◽  
Aerosol Exposure ◽  
Aerosol Emissions

Abstract. Particles, climate change, and health have thought-provoking interactions. Emission of aerosol particles is one of the largest environmental problems concerning human health. On the other hand, aerosol particles can have a cooling effect on climate and a reduction of those emissions may result in an increased temperature, which in turn may have negative health effects. The objective of this work was to investigate the "total health" effects of aerosol emissions, which include both exposure to particles and consequences of climate change initiated by particles. As a case study the "total health" effect from ship emissions were estimated by adding the number of deaths from aerosol emission exposure to the calculated number of lives saved from the cooling effect of the particles. The analysis indicated an annual mortality from ship emissions of 26 000 (minimum uncertainty range −5000 to 52 000), with 60 000 deaths from direct aerosol exposure and 34 000 lives saved by the cooling effect of particles. This is the first attempt to calculate the combined effect of particle emissions on health. We conclude that measures to reduce particulate air pollution will in some cases (black carbon) have win-win effects on health and climate, but for most particulates cause a shift from exposure-related health effects towards an increasing risk of health consequences from climate change. Thus, measures to reduce aerosol emissions have to be coupled with climate change mitigation actions to achieve a full health benefit on a global level.

On the lifecycle of a shallow cumulus cloud: Is it a bubble or plume, active or forced?

2021 ◽  
Author(s):  
David M. Romps ◽  
Rusen Öktem ◽  
Satoshi Endo ◽  
Andrew M. Vogelmann
Keyword(s):  
Cloud Cover ◽  
Large Eddy Simulations ◽  
The Other ◽  
Doppler Lidar ◽  
Cumulus Cloud ◽  
Cumulus Clouds ◽  
Shallow Cumulus ◽  
Large Eddy ◽  
Stereo Cameras ◽  
Using Data

AbstractA cloud’s lifecycle determines how its mass flux translates into cloud cover, thereby setting Earth’s albedo. Here, an attempt is made to quantify the most basic aspects of the lifecycle of a shallow cumulus cloud: the degree to which it is a bubble or plume, and active or forced. Quantitative measures are proposed for these properties, which are then applied to hundreds of shallow cumulus clouds in Oklahoma using data from stereo cameras, a Doppler lidar, and large-eddy simulations. The observed clouds are intermediate between active and forced, but behave more like bubbles than plumes. The simulated clouds, on the other hand, are more active and plume-like, suggesting room for improvement in the modeling of shallow cumulus.

scholarly journals Notes Toward a Meteorology of the Cloud

2015 ◽  
Vol 13 (2) ◽  
pp. 283-291
Author(s):  
Elliot Vredenburg
Keyword(s):  
Law Enforcement ◽  
Cloud Cover ◽  
Search Term ◽  
Cumulus Cloud ◽  
Meteorological Observation ◽  
Cumulus Clouds ◽  
Computing Services ◽  
Cloud Computing Services ◽  
Targeted Marketing ◽  
Government Surveillance

The premise of detailed forecasts is meteorological observation. An ominous cloud has eclipsed the global horizon of neoliberal capitalist realism. Researching cloud formations, I queried Google with the search term “clouds.” However, when using the term “cloud,” I only received results about server-based computing. Thus the cloud is singular, not plural: 100% cloud cover, blanketing the sky with grey. This is not a marketing-friendly cumulus cloud, but rather a dark, sheetlike formation—what meteorologists call a pallium. Whereas curative approaches require consideration and cogitation—care—what the pallium offers instead is palliation; alleviation of symptoms without any real remedy. In accordance with the techno-utopian walled garden, opposing or divergent views are eradicated under the pallium, leaving us with an AstroTurfed landscape that is paralyzing in its uniformity. Luke Howard’s categories of tropospheric clouds parallel the multifarious manifestations of the contemporary cloud: in commercial data collection for targeted marketing, as well as in government surveillance for preemptive law enforcement. A digital meteorology of these formations—the benign cumuliform, appearing in the logos of corporate cloud-computing services; the grey, ominous stratiform; and the striated, interstellar cirriform—must be considered, in order to predict and prepare for the imminent approach of the panoptic pharmakon of the pallium, as it arrives under the guise of a swarm of cutesy cumulus clouds. Drawing from studies of panopticism, contemporary marketing practices, and the effluence tapped by Edward Snowden, this essay deploys hydrous analogies to forecast whether anything but AstroTurf can survive in the current climate.

scholarly journals Solar geoengineering may not prevent strong warming from direct effects of CO2on stratocumulus cloud cover

2020 ◽  
Vol 117 (48) ◽  
pp. 30179-30185
Author(s):  
Tapio Schneider ◽  
Colleen M. Kaul ◽  
Kyle G. Pressel
Keyword(s):  
Global Warming ◽  
Greenhouse Gas ◽  
Cloud Cover ◽  
Radiative Cooling ◽  
Direct Effects ◽  
Cumulus Clouds ◽  
Stratocumulus Clouds ◽  
Solar Geoengineering ◽  
Subtropical Oceans ◽  
Fail Safe

Discussions of countering global warming with solar geoengineering assume that warming owing to rising greenhouse-gas concentrations can be compensated by artificially reducing the amount of sunlight Earth absorbs. However, solar geoengineering may not be fail-safe to prevent global warming because CO2can directly affect cloud cover: It reduces cloud cover by modulating the longwave radiative cooling within the atmosphere. This effect is not mitigated by solar geoengineering. Here, we use idealized high-resolution simulations of clouds to show that, even under a sustained solar geoengineering scenario with initially only modest warming, subtropical stratocumulus clouds gradually thin and may eventually break up into scattered cumulus clouds, at concentrations exceeding 1,700 parts per million (ppm). Because stratocumulus clouds cover large swaths of subtropical oceans and cool Earth by reflecting incident sunlight, their loss would trigger strong (about 5 K) global warming. Thus, the results highlight that, at least in this extreme and idealized scenario, solar geoengineering may not suffice to counter greenhouse-gas-driven global warming.

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