The protective layers of the atmosphere, most specifically the ozone layer and the ionosphere, are being shredded
by the aerosol clouds.
Not exact matches
Scientists can measure how much energy greenhouse gases now add (roughly three watts per square meter), but what eludes precise definition is how much other factors — the response of
clouds to warming, the cooling role of
aerosols, the heat and gas absorbed
by oceans, human transformation of the landscape, even the natural variability of solar strength — diminish or strengthen that effect.
By absorbing heat,
aerosols can evaporate nearby
cloud droplets — making the
cloud less reflective and compounding the heating effect.
On the other hand,
by warming the atmosphere,
aerosols can stabilize the air and protect
clouds from drying out and thinning.
The team started
by looking at the formation of the very small particles — a process called
aerosol nucleation —
by mimicking atmospheric conditions inside an ultraclean steel «
cloud chamber», which Kirkby says is the cleanest ever created.
And
by carefully measuring and modeling the resulting changes in atmospheric composition, scientists could improve their estimate of how sensitive Earth's climate is to CO2, said lead author Joyce Penner, a professor of atmospheric science at the University of Michigan whose work focuses on improving global climate models and their ability to model the interplay between
clouds and
aerosol particles.
The difference in lightning activity can't be explained
by changes in the weather, according to the study's authors, who conclude that
aerosol particles emitted in ship exhaust are changing how storm
clouds form over the ocean.
Experiments Prather and her team conducted in California's Sierra Nevada produced the first conclusive evidence that dust
aerosols can change the amount of precipitation produced
by clouds.
On their own,
aerosol particles are tiny; when a
cloud droplet becomes a rain droplet, it grows
by a factor of a million as droplets crash and coalesce together.
Despite its smaller ash
cloud, El Chichn emitted more than 40 times the volume of sulfur - rich gases produced
by Mt. St. Helens, which revealed that the formation of atmospheric sulfur
aerosols has a more substantial effect on global temperatures than simply the volume of ash produced during an eruption.
Ultimately, scientists hope to learn how
aerosols affect
clouds, how much
aerosols are produced
by humans and nature and how they travel in the atmosphere.
The interactions between
clouds and
aerosols are illustrated in this image, taken
by retired astronaut Chris Hadfield onboard the International Space Station.
Yu and his colleagues analyzed dust transport estimates based on data collected
by NASA's
Cloud -
Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite between 2007 and 2013.
Aerosols are already known to reduce global warming: The vast
clouds of sulfates thrown up in the 1991 eruption of Mount Pinatubo in the Philippines, for example, reduced average global temperatures
by about half a degree Celsius.
Albedo modification might also work
by using
aerosols to seed
cloud formation in a lower atmospheric layer called the troposphere.
A model developed
by Koren and his team showed that an increase in
aerosols, even in relatively polluted conditions, should result in taller, larger
clouds that rain more aggressively.
That's the conclusion of a team of scientists using a new approach to study tiny atmospheric particles called
aerosols that can influence climate
by absorbing or reflecting sunlight and seeding
clouds.
Other
aerosols can bring about temporary atmospheric cooling, mainly
by seeding
clouds that linger in the atmosphere longer than they normally would, or
by scattering light.
Rosenfeld and his students have developed an
aerosol quantification method that uses satellite - based measurements of the infrared light reflected
by clouds.
If
aerosol quantities are known, they can of course be compared with how much lightning is later produced
by the
cloud in question.
This mission is fulfilled
by operating atmospheric observatories around the world that collect massive amounts of atmospheric measurements to provide data products that help scientists study the effects and interactions of
clouds and
aerosols and their impact on the earth's energy balance.
FMI has been involved in research project, which evaluated the simulations of long - range transport of BB
aerosol by the Goddard Earth Observing System (GEOS - 5) and four other global aerosol models over the complete South African - Atlantic region using Cloud - Aerosol Lidar with Orthogonal Polarization (CALIOP) observations to find any distinguishing or common model
aerosol by the Goddard Earth Observing System (GEOS - 5) and four other global
aerosol models over the complete South African - Atlantic region using Cloud - Aerosol Lidar with Orthogonal Polarization (CALIOP) observations to find any distinguishing or common model
aerosol models over the complete South African - Atlantic region using
Cloud -
Aerosol Lidar with Orthogonal Polarization (CALIOP) observations to find any distinguishing or common model
Aerosol Lidar with Orthogonal Polarization (CALIOP) observations to find any distinguishing or common model biases.
It comes from ARM and James Hansen's references to global dimming developing from
clouds being enhanced and or formed
by pollution, sulfates, and or certain
aerosols and so forth.
A multidisciplinary team led
by Pacific Northwest National Laboratory's Dr. Chuck Long found that, at least in the continental United States, changes in
clouds and cloudiness have a greater influence on brightening than any decrease in
aerosol amounts alone.
Aerosols tend to have a cooling effect
by scattering sunlight and
by encouraging
clouds to form, preventing the sun's energy reaching Earth's surface.
Climate is not different, as can be seen in the fact that a broad range of
cloud feedbacks (compensated
by other parameters...) or a range of combined
aerosol / CO2 sensitivities is able to fit the temperature of the past century.
Sally, who was nominated
by Dr. Beat Schmid, Associate Director, Atmospheric Sciences and Global Change Division, was honored for her exceptional contribution in the field of atmospheric science, particularly in her efforts to improve understanding of the radiative effect of
clouds and
aerosols on the Earth's atmosphere and their representation in climate models.
A team of scientists led
by Pacific Northwest National Laboratory atmospheric researcher Dr. Susannah Burrows and collaborator Daniel McCoy, who studies
clouds and climate at the University of Washington, reveal how tiny natural particles given off
by marine organisms — airborne droplets and solid particles called
aerosols — nearly double
cloud droplet numbers in the summer, which boosts the amount of sunlight reflected back to space.
For example, the authors acknowledge the role of
aerosols in stimulating
clouds to form and the darkening of snow and ice
by black carbon, adding that there is still too much uncertainty to include fully in their calculations.
A large portion of secondary organic
aerosols - tiny particles in the air we breathe that contribute to
cloud formation and precipitation - arise from a combination of man - made pollution and molecules given off
by plant matter.
CLOUD shows that organic vapours emitted
by trees produce abundant
aerosol particles in the atmosphere in the absence of sulphuric acid.
The
Aerosol Climate Initiative is an investment by Pacific Northwest National Laboratory that will advance the science of aerosol and cloud modeling and measurement capabi
Aerosol Climate Initiative is an investment
by Pacific Northwest National Laboratory that will advance the science of
aerosol and cloud modeling and measurement capabi
aerosol and
cloud modeling and measurement capabilities.
The simulations confirm that
aerosol injection does brighten
clouds, but the amount of solar radiation reflected may not be enough to balance the global warming caused
by burning fossil fuels.
The indirect
aerosol effect on
clouds is non-linear [1], [76] such that it has been suggested that even the modest
aerosol amounts added
by pre-industrial humans to an otherwise pristine atmosphere may have caused a significant climate forcing [59].
In accordance with
Aerosol, Clouds, and Trace gases Research Infrastructure (ACTRIS) activities, the main goal of the campaign will be vertical profiling of gases,
aerosols and
cloud properties
by unique combination of in - situ and remote sensing techniques.
Earth's measured energy imbalance has been used to infer the climate forcing
by aerosols, with two independent analyses yielding a forcing in the past decade of about − 1.5 W / m2 [64], [72], including the direct
aerosol forcing and indirect effects via induced
cloud changes.
The planet's albedo, around 30 percent, is governed
by cloud cover and the quantity of atmospheric particles called
aerosols.
Although most
aerosols are carried up
by the same atmospheric circulation patterns, their chemical and physical properties determine whether or not they become «
cloud condensation nuclei,» which are the points around which droplets form before they become
cloud droplets.
The creation of these artificial
clouds are known
by several terms: aerial spraying,
aerosol spraying, solar radiation management, or stratospheric
aerosol injection.
But, as far as I can see, the «attacks»
by vested interests are not even able to make legitimate points (e.g. uncertainty about the effects of
clouds or
aerosols in climate models).
Prior to the publication of the
aerosol nucleation results from the
CLOUD experiment at CERN in Nature several weeks ago Kirkby et al, 2011, I was asked
by Nature Geoscience to write a «News and Views» on the
CLOUD results for a general science audience.
The microphysical
cloud processes,
aerosol interactions, etc which are not resolved (spatially)
by models or are not reducible to simple algebraic answers must be constrained heavily and talked about with uncertanity.
This includes the energy trapped
by photosynthesis, the majority that is not re-radiated, plus energy that is prevented from re-radiating back
by reflecting from
cloud cover or
aerosols, absorbed
by GHGs, and other mechanisms.
«
Cloud water content as gauged
by the Special Sensor Microwave / Imager (SSM / I) reaches a minimum ~ 7 days after the Forbush minimum in cosmic rays...» Svensmark et al, «Cosmic ray decreases affect atmospheric
aerosols and
clouds», GEOPHYSICAL RESEARCH LETTERS,
Climate is not different, as can be seen in the fact that a broad range of
cloud feedbacks (compensated
by other parameters...) or a range of combined
aerosol / CO2 sensitivities is able to fit the temperature of the past century.
If solar is increased
by feedbacks (like
cloud cover), that will give the same fit of past temperature data at the cost of combined GHG +
aerosol.
For 15 years the prediction of warming resulting from a doubling of CO2 has varied
by 300 % from 1.5 to 4.5 K. For 15 years the climate modellers have been claiming it will take them 15 years to get the
clouds and
aerosols right.
Aerosols exert a forcing on the hydrological cycle
by modifying
cloud condensation nuclei, ice nuclei, precipitation efficiency, and the ratio between solar direct and diffuse radiation received.
We have performed such experiments for the principal greenhouse gases,
clouds, and
aerosols using the [Goddard Institute] climate model
by systematically inserting, or taking out, each atmospheric constituent one at a time, and recording the corresponding radiative flux change.
Many environmental factors influence the convective life cycle in this region, including orographic, low - level jet, and frontal circulations, surface fluxes, synoptic vertical motions influenced
by the Andes,
cloud detrainment, and
aerosol properties.