A_Ch2_AtmosphericConstituents,RF

Vocabulary: Anthropogenic: Air pollution caused by humans Radiative forcing (RF): comparisons of the strength of different human and natural causes that might assist in climate change. GWP: Global warming potential

Introduction and Scope:(Linda Angel) These written materials show an update of information from chapters three to six of the IPCC Working Group Third Assessment Report (2001). Concerning forcing agents and their precursors. It includes their estimate contribution to radiative forcing of the climate system. It also analyzes human produced carbon output/greenhouse gas changes, aerosol changes, and how they impacted the weather and cloud s.





This reanalyzes radiative forcing, expressing space and time patterns by examining the radiative energy changes on Earth’s surface ; Greenhouse gases such as carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, hydro-chlorofluorocarbons (HCFC’s), Hydro-fluorocarbons (HFC’s), Per-fluorocarbons (PFC’s), and Sulfur hexafluoride. In this chapter, only 'Forward Calculation' methods for estimating RF. The estimates rely on observations and/or modeling of the RF agents. Since the very first study of the RF, several others tried to constrain the aspects using 'inverse calculation' in more than one particular climate. Some of these methods are commonly used and Aerosols, temperatures, other RFs, climate response and ocean heat uptake. Chapter 9.2 has more information of the understanding of these estimates. Chapters six, seven, and ten also have discussions about atmospheric changes and Radiative Forcing.

Concept of Radiating Forces:

Chemically and Radiatively Important Gases: by Gabriel Dias

In the 1980’s and the 1990’s it was required to take CO2 measurements over continental area to provide the base for estimations of sources and sinks of atmospheric CO2 over land as well as regions of ocean. A large number of samples and tests conducted for climate change all over the world are done by the professionals at NOAA/CMDL. Since the industrial period CO2 emissions’ being released has steadily increased with any form of hesitation, due to the fact of our large industrial plants producing a vast amount of CO2 gasses and the deforestation of plant causing the absorption of CO2 to vastly drop.



Methane levels have increased steadily over the progression of years. This is suggested by ice core experiments and studies.

Aerosols: A system of colloidal particles dispersed in a gas; smoke or fog.(Isabel Vega)

Aerosols scatter and absorb short wave and long wave radiation, therefore it alters the radiative ba lance in the Earth's-atmosphere system.

Anthropogenic Changed in Surface Albedo and the Surface Energy Budget:

Contrails and Aircraft-Induced Cloudiness: (Isabel Vega)

Contrails are thin cirrus clouds, which reflect solar radiation and trap outgoing long wave radiation. Contrail cover calculations are uncertain because there aren't many super saturated regions in the atmosphere that are known. Individual persistent contrails are observed to shear and spread. Spreading contrails loose their characteristic linear shape, and because of this when AIC amounts are trying to be estimated it ends up becoming unclear because most of the time it is confused by background cirrus. The absence of AIC has been concluded to be the reason for the increased diurnal temperature range (DIR). However, conclusions are not really accurate because they are based off of correlation rather than quantitative model. Most conclusions are made off of very little data. A worry that comes up is that aviation aerosol can act as a nuclei in an ice cloud formation, altering the micro-physical properties of clouds. Aviation aerosols either increase or decrease ice nuclei in the background cirrus clouds. Changes in nucleation properties of aerosols can alter the radiative properties of cirrus clouds. No conclusions or guesses are made yet for the global or regional RF changes caused by the effect of aviation aerosol on background cloudiness, although some of the RF from AIC, has been determined by correlation studies .

Natural Forcings: (Isabel Vega)

Utility of Radiative Forcing:

Synthesis: Kayla Umstead

The concept of Radiative Forcing is important to understand in looking at climate change. Radiative Forcing is also called RF. The RF is a measure of equilibrium climate change used to compare with others. There are many ways to measure and calculate the RF, depending on the agent. Changes in emissions and concentrations can strongly affect the RF, which strongly depends on the history of emissions. The RF can also somewhat predict climate change in the future Sometimes, when calculating Radiative Forcing (RF), there are uncertainties and problems that cause the wrong result. To identify these uncertainties, there’s an attached error bar to each RF term that was guided by the range of published values and physical understanding. Error bars are 90% correct, and help scientist understand their uncertainties. The evidence provided from an error bar, is from an A to C grade, with an A grade implying strong evidence and a C implying weak evidence.



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Global Warming Potentials and Other Metrics for Comparing Different Emissions : Kayla Umstead The Global warming potential, also called the GWP is one of the methods of comparing different emissions. These methods were created to help limit climate change. GWP, or other emission metrics provide a tool that can be used to help the change in climate, and so that multi-gas emitters can compose mitigation measures.

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Self Reflections:

Isabel Vega  Aerosols are air borne products consisting in part with at least some solid materials; a huge natural source of aerosols is the oceans. Aerosols are affected by human activity by air pollution and water contamination I affect aerosols by driving to school every morning or by just transportation in general. Another way I affect the aerosols are by brushing my teeth every morning and by using harsh chemicals to clean. The aerosols play a big role in global climate balance; therefore they are what mainly affect the climate. Aerosols affect climate mainly by controlling the amounts of radiation the Earth takes and gives off then as infrared radiation. Aerosols have two affects which are direct radiative forcing and indirect radiative forcing. Direct radiative forcing is the scattering of solar radiation and the absorption/emission of terrestrial radiation; and indirect radiative forcing is mainly the effects of aerosols on cloud properties. Greenhouse gases react at the surface of an aerosol and change radiative properties. Greenhouse gases are the mainly affected by human activity by the amounts of carbon dioxide that are being put into the atmosphere. As the carbon footprint stated I do tend to put as must pollution and do waste as much energy as an average human. Which is in a way really important because the more energy that is wasted the more fossil fuels are being used and therefore inputting more and more air pollution.

 The other chapters I read were tied into this because in a way aerosols control a really important part of climate change. And if there weren't as much contamination occurring aerosols would be more controlling of the climate, although contamination would also be a threat to earth because without it the aerosols would fall down into creating mainly a cold climate change putting earth in jeopardy.