The brass ring of climate modeling

The brass ring of climate modeling
The simple model of aerosol effects on clouds and climate shows the complex, physically based relationships between emissions, aerosol concentrations, droplet concentrations, cloud reflectance, and the Earth’s energy balance.

Finding a simple way to express complex climate processes is the ultimate prize. Scientists at Pacific Northwest National Laboratory, University of Leeds, Colorado State University, the National Aeronautics and Space Administration (NASA), and Carnegie Mellon University developed a simple mathematical model to represent how atmospheric aerosol particles affect the Earth's energy balance through their role in forming cloud droplets. The simple model not only efficiently and effectively describes complex processes, but the results are consistent with those from much more detailed global climate simulations.

"Integrated assessment models used to explore emissions scenarios often use a crude treatment of indirect effect processes," said Dr. Steven J. Ghan, lead author and atmospheric scientist at PNNL. "Our model fills the need for a simple treatment with a stronger physical basis. The research team applied understanding of the physical mechanisms involved in a diverse set of global aerosol models."

How aerosol particles affect clouds is one of the most difficult challenges facing climate modelers because the processes involved are very complex. (See sidebar, Indirect and Direct Effects of Aerosols). Whether represent this complexity depends on gathering and calculating all the relevant processes, and doing so at every grid cell of the model. This challenge is often formidable and can take an enormous amount of computational power. The simple model developed in this research is much more efficient and produces similar estimates of the global average impact of the aerosol indirect effect in a small fraction of time. This type of solution is useful for improving understanding of what determines the aerosol indirect effect. Scientists can also use it to run multi-century simulations with models designed to explore the impacts of different energy technology options.

The research team designed a simple model that uses physically based relationships between emissions, aerosol concentrations, droplet concentrations, cloud reflectance, and the Earth's energy balance, and accounts for spatial variations in both aerosols and clouds.

The model is now available to the university community as a teaching tool and to the integrated assessment community to better represent the complexity of the aerosol indirect effect.


Explore further

Connecting the dots on aerosol details

More information: Ghan, S. et al. 2013. A Simple Model of Global Aerosol Indirect Effects, Journal of Geophysical Research Atmospheres 118:1-20. DOI: 10 1002/jgrd 50567
Citation: The brass ring of climate modeling (2013, August 5) retrieved 17 September 2019 from https://phys.org/news/2013-08-brass-climate.html
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BSD
Aug 05, 2013
It wouldn't matter how you express it. The Loony Right and other conservative nutjobs including Christians, treat global warming as just another conspiracy and an attack on them.

The strange thing about these right wing types are they don't believe in science but believe in bullshit like god. Strange bastards. Australia is full of them unfortunately.

Aug 05, 2013
Right-wingers failed basic,high-school chemistry. I don't think they will ever understand science.

It's simple really...

Molecules like CO2 and CH4 both absorb infrared rays from the sun and trap heat (change in entropy in thermodynamics) via endothermic reactions.

We have cut down over 50% of the Earth's forests. Those forests are needed as a whole to filter out any pollution.

All of mankind's factories...Emit more sulfur than all of the Earth's volcanoes combined.

Corals use a naturally occurring form of calcium carbonate called aragonite to make their skeletons. When the oceans absorb our massive C02 emissions...It forms carbonic acid.
Which,in turn,lowers the pH level of water. All ocean life will die...And human economies and humans soon after.

There's so much more.

Aug 05, 2013
As an atheist I don't see Global Warming alarm as a conspiracy but as a boringly mind numbing combination of: (1) noble cause corruption, and (2) confirmation bias, catalyzed into self-organized glory by a activist federal funding by those who wish to tax air.

Utter lack of compassion towards and appreciation of religious folk disqualifies Gore's doomsday cult members from being able to relate to the other 90% of the human race. After Climategate of late 2009, it only took us online skeptics a few months of outreach to convert the whole right wing of politics to not only knee jerk opposition but quite sophisticated skepticism where they get the details right too. Hopefully in the process they now enjoy better access to competent science advice in general, something that may prevent future embarrassments such as Sarah Palin's flippant dismissal of all of fruit fly research, one of the core pillars of biology.

Global Warming activists misunderstand both skepticism, and the weather too.

Aug 05, 2013
Nic says: "Global Warming activists misunderstand both skepticism, and the weather too."

How long will it take for you to remember the difference between weather and climate?

Aug 05, 2013
kevin mused: "Right-wingers failed basic,high-school chemistry. I don't think they will ever understand science. / It's simple really... / Molecules like CO2 and CH4 both absorb infrared rays from the sun and trap heat (change in entropy in thermodynamics) via endothermic reactions."

That's just the greenhouse effect, you know the one the vast majority of informed skeptics agree will add about a degree of enhanced warming for each doubling of CO₂. What all climate alarm is based on is the highly speculative notion embodied in academic supercomputer models that there exists a single massive (3X) amplification of this otherwise quite pleasant extra warming.

Your forest loss claim is quite backwards since it is quite uncontroversial that our high CO₂ era is directly responsible for a huge multi-digit percent increase in forest cover in recent decades.

"All ocean life will die...And human economies and humans soon after."

Ugh: http://www.mendel...-007.jpg

Aug 05, 2013
Nic says: "How long will it take for you to remember the difference between weather and climate?


Righteous dude, clichés are not effective arguments.

"Superstorm" (actually failed cyclone) Sandy that flooded the tip of Manhattan were I live near Columbia University where a future Amer. Chem. Soc. president (Breslow) and future biology Nobelist (Chalfie) were on my Ph.D. defense committee after I won the top organic chemical division award that year before spending three more years at Harvard, this little storm surge was weather, but politicians who now control R&D funding called it Climate Change.

Did I pass?

Aug 05, 2013
Neinsense:

How dare you accuse me of unsupported muck pandering to the pre-contemplative!

I'll have you know I snagged o'ttrella frapilongle durn myers questoon, afteree rangoon barroned a gogleplex.

There was in fact a collective shiver on the clearinghouse skeptical blog WattsUpWithThat after first Rush Limbaugh and then Glenn Beck reported on Climategate, and right wing politics suddenly rushed into our nerd box.

Aug 05, 2013
So when False Prophet Gore proclaimed the science was settled, that was just another AGW Alarmist lie.

Aug 05, 2013
So when False Prophet Gore proclaimed the science was settled, that was just another AGW Alarmist lie.
What a dim bulb you are anti.

Another one of the wiener patrol says
There was in fact a collective shiver on the clearinghouse skeptical blog WattsUpWithThat after first Rush Limbaugh and then Glenn Beck reported on Climategate, and right wing politics suddenly rushed into our nerd box.


Yeap! Sounds about right Ethel.

Aug 06, 2013
Here is my model.
You put an extra blanket on, it gets warmer.
The rest is stuff and nonsense.

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