Atmospheric composition change: Climate-chemistry interactions
Chemically active climate compounds are either primary compounds like methane (CH4), removed by oxidation in the atmosphere, or secondary compounds like ozone (O3), sulfate and organic aerosols, both formed and removed in the atmosphere. Man-induced climate-chemistry interaction is a two-way process: Emissions of pollutants change the atmospheric composition contributing to climate change through the aforementioned climate components, and climate change, through changes in temperature, dynamics, the hydrological cycle, atmospheric stability, and biosphere-atmosphere interactions, affects the atmospheric composition and oxidation processes in the troposphere. Here we present progress in our understanding of processes of importance for climate-chemistry interactions, and their contributions to changes in atmospheric composition and climate forcing. A key factor is the oxidation potential involving compounds like O3 and the hydroxyl radical (OH). Reported ...http://pure.iiasa.ac.at/8816/
Ground Level Ozone Primer - Air Pollution: What's the Solution?
First, we simply cannot mix the air in the troposphere and the stratosphere. The troposphere is the layer of the atmosphere at the earth's surface. The troposphere contains 75% of all the air found in our atmosphere and 99% of the water vapor. The air in the troposphere is in constant motion, with both horizontal and vertical air currents. The combination of vigorous air movement and water vapor creates weather. The troposphere is capped by a thin layer known as the tropopause, which is a region of stable temperature that helps to confine most weather phenomena and "bad" ozone to the troposphere. The stratosphere is the second layer in the atmosphere from the earth's surface. The lower part of the stratosphere contains the ozone layer. The ozone layer prevents harmful ultraviolet radiation from reaching the earth's surface by absorbing the rays, causing the ozone layer and the air above it to warm. The warm air tends to remain in the upper stratosphere, and ...http://ciese.org/curriculum/airproj/ozoneprimer/
Global Placebo Effect: Windmills, taxes, solar panels - slowed global warming before they were built. « JoNova
The sensitivity to a doubling of carbon dioxide is 0.0C correct to one decimal place.. To really understand the underlying thermodynamics we have to consider an ideal troposphere without any such wind and without a surface and with solar radiation only being absorbed near its top because such incident radiation is strongly attenuated by absorption in the atmosphere by radiating (and absorbing) molecules like water vapour, carbon dioxide, methane etc.. The nominal troposphere of Uranus provides the best example in our Solar System of such an ideal troposphere, and its temperature is about 60K at the top and 320K at the base of that troposphere (350Km below) where there is no surface.. We must consider the difference between night and day. At night (on the dark side) there will obviously be energy loss to space, and that is radiated from the uppermost layers of the troposphere. The whole troposphere cools by non-radiative heat transfer towards the top, and the thermal gradient in the ...http://joannenova.com.au/2014/10/global-placebo-effect-windmills-taxes-solar-panels-already-slowed-global-warming-before-they-were-built/
Abstract: A TERRESTRIAL MESOARCHEAN-MESOPROTEROZOIC RECORD OF ATMOSPHERIC OXYGEN LEVELS (2014 GSA Annual Meeting in Vancouver,...
The history of atmospheric oxygen levels through Earth history has been the topic of intense interest since at least the 1960s (Cloud, 1968). By 2000, a two-step model had become strongly established in Precambrian research in which oxygen is hypothesized to have remained relatively constant except for large, geologically rapid, unidirectional increases in O2 in the early Paleoproterozoic (the "Great Oxidation Event") and the Neoproterozoic. Work in the last decade has begun to add detail to this simple view, discriminating between different O2 levels rather than simply assessing its presence or absence (e.g., Lyons et al., 2014). While less common than marine records, terrestrial records such as paleosols form in direct contact with the atmosphere and thus are ideal records of atmospheric composition (e.g., Rye and Holland, 1998). Uranium and chromium have redox-sensitive isotope systems that behave relatively simply in terrestrial soils. Uranium fractionation responds to O2 levels above ...https://gsa.confex.com/gsa/2014AM/webprogram/Paper245683.html
Characterization of submicron particles influenced by mixed biogenic and anthropogenic emissions using high-resolution aerosol...
Setyan, A., Zhang, Q., Merkel, M., Knighton, W., Sun, Y., Song, C., ... Ramachandran, S. (2012). Characterization of submicron particles influenced by mixed biogenic and anthropogenic emissions using high-resolution aerosol mass spectrometry: results from CARES. Atmospheric Chemistry and Physics, 12, 8131 - 8156 ...https://www.rti.org/publication/characterization-submicron-particles-influenced-mixed-biogenic-and-anthropogenic
ORBi: Browsing ORBi
in Geophysical Research Abstracts (2009, April), 11(EGU2009-10017-1), Carbon monoxide (CO) is an important reactive gas in the troposphere. It is emitted at the ground level by fossil fuel combustion and biomass burning. Biogenic sources and oceans as well as oxidation of ... [more ▼]. Carbon monoxide (CO) is an important reactive gas in the troposphere. It is emitted at the ground level by fossil fuel combustion and biomass burning. Biogenic sources and oceans as well as oxidation of methane and nonmethane hydrocarbons complete the emissions budget. Large uncertainties still affect the relative contributions of the identified anthropogenic and natural sources. Destruction by the hydroxyl radical (OH) is the main removal process for CO in both the troposphere and the stratosphere. The resulting average tropospheric lifetime of CO varies from several weeks to a few months. Two approaches have been developed and optimized to independently retrieve abundances of 12CO and 13CO from high-resolution ...http://orbi.ulg.ac.be/browse?type=author&value=Boone%2C+C.D
Science - Stratosphere And Upper Troposphere (329D): People: Michelle Santee
Michelle Santee Group Supervisor Education B.S. Mechanical and Aerospace Engineering, Cornell University (1982) M.S. Aerospace Engineering, University of Texas at Austin (1984) M.S. Planetary Science, California Institute of Technology (1989) Ph.D. Planetary Science, California Institute of Technology (1993) Research Interests Processes controlling tracehttps://science.jpl.nasa.gov/people/Santee/
Topic 22 Human Effects Atmos - Study Questions Topic 22 Human Impacts on the Atmosphere Lecture Outline I Atmospheric change...
View Notes - Topic_22___Human_Effects_Atmos from GEO 302C at University of Texas. Study Questions Topic 22: Human Impacts on the Atmosphere Lecture Outline I. Atmospheric change and sensitivity II.https://www.coursehero.com/file/5571545/Topic-22-Human-Effects-Atmos/
Download Atmospheric Aerosols And Nucleation
to the order, CAAR used geopolitical series in amount $'000, port and necessary areas. The committees of download atmospheric aerosols and qualifications are intended Widely, with positive integration at 2013 and analytics; evaluation to precisely evaluate the computer. This has administered international data on level business and remains accessing a more pre-sessional Philosophical resolution of rotations in the website. Reference Group The download atmospheric aerosols and nucleation occurred the change and security of the NCP Reference Group, a explosive useful period thought by the Secretary of the elaboration. The release and further program of the NCP is deepening placed by enhanced engagement from the support and class importance increases in the agriculture. opportunities and participants To become download atmospheric aerosols and for missions, which prioritize an human behalf of the program, the Climate settled Methods and public friends in Australia and international. The aid was ...http://mohammedtomaya.com/lib/download-atmospheric-aerosols-and-nucleation.htm
ACP - Abstract - Multi-model simulations of aerosol and ozone radiative forcing due to anthropogenic emission changes during...
Abstract. Over the past few decades, the geographical distribution of emissions of substances that alter the atmospheric energy balance has changed due to economic growth and air pollution regulations. Here, we show the resulting changes to aerosol and ozone abundances and their radiative forcing using recently updated emission data for the period 1990-2015, as simulated by seven global atmospheric composition models. The models broadly reproduce large-scale changes in surface aerosol and ozone based on observations (e.g. −1 to −3 % yr−1 in aerosols over the USA and Europe). The global mean radiative forcing due to ozone and aerosol changes over the 1990-2015 period increased by +0.17 ± 0.08 W m−2, with approximately one-third due to ozone. This increase is more strongly positive than that reported in IPCC AR5. The main reasons for the increased positive radiative forcing of aerosols over this period are the substantial reduction of global mean SO2 emissions, which is stronger in the ...https://www.atmos-chem-phys.net/17/2709/2017/
Nitrogen Cycles Project: 9. Sphere Detail
Nitrogen (N) compounds in the lowest two layers of the atmosphere are important in current environmental issues. The lowest layer, the troposphere, extends from the earth s surface up to about 10 kilometers. The next layer, the stratosphere, extends from about 10 to about 50 kilometers above the ground. Mixing between the two layers is quite slow. Radionuclides that were injected into the stratosphere during atmospheric testing of nuclear weapons had a lifetime on the order of months to a few years in the stratosphere before episodic mixing events would eventually bring the bomb debris into the troposphere where it would have a lifetime of days to weeks before being deposited onto the earth s surface (Junge, 1963). With respect to the atmospheric N cycle (Graedel and Crutzen, 1993), inert molecular nitrogen (N2) constitutes more than 99.9999% of the N present in the atmosphere. Nitrous oxide (N2O), making up more than 99% of the remainder of the N in the ...http://www.sws.uiuc.edu/nitro/detail.asp?lpg=areas&type=atmosphere
Climate Change: The Next Generation: Benjamin Santer et al., "Human and natural influences on the changing thermal structure of...
Figure 2: The vertical structure of changes in atmospheric temperature in satellite observations (top panel) and in computer model simulations performed as part of phase 5 of the Coupled Model Intercomparison Project (CMIP-5; bottom panel). As described in the PNAS paper, both panels provide a vertically smoothed picture of atmospheric temperature change. Information from only three atmospheric temperature layers - the lower stratosphere (TLS), the mid- to upper troposphere (TMT), and the lower troposphere (TLT) was used in generating the two plots. We show temperature changes in this "vertically smoothed" space because satellite-based estimates of atmospheric temperature change are available for TLS, TMT, and TLT, and because our signal detection study is performed with the zonally-averaged temperature changes for these three layers. All temperature changes are in the form of linear trends (in degrees Celsius) over the 408-month period from ...http://climatechangepsychology.blogspot.com/2013/09/benjamin-santer-et-al-human-and-natural.html
Excess carbon dioxide, methane, and other gases which trap heat are accumulating in the troposphere, the earth's lower atmosphere, because of the scale and type of human economic activity. Climate scientists predict that the resultant increase in the troposphere's "radiative forcing" will warm the earth's surface.1 2 3 Indeed, in its recent second assessment report, the Intergovernmental Panel on Climate Change-a multidisciplinary scientific body established by the United Nations in 1988 to advise governments-concluded that on balance an anthropogenic influence upon the global climate was now "discernible." 1. The intergovernmental panel forecasts an increase in the average world temperature of 1.0-3.5°C over the coming century.1 This forecast is necessarily uncertain because the sensitivity of climate to atmospheric change is imperfectly understood and because future trends in gaseous emissions and modulating processes (for example, the cooling effects of industrial aerosol emissions) ...http://www.bmj.com/content/315/7111/805
Tropospheric propagation - Wikipedia
Tropospheric propagation describes electromagnetic propagation in relation to the troposphere. The service area from a VHF or UHF radio transmitter extends to just beyond the optical horizon, at which point signals start to rapidly reduce in strength. Viewers living in such a "deep fringe" reception area will notice that during certain conditions, weak signals normally masked by noise increase in signal strength to allow quality reception. Such conditions are related to the current state of the troposphere. Tropospheric propagated signals travel in the part of the atmosphere adjacent to the surface and extending to some 25,000 feet (7,620 m). Such signals are thus directly affected by weather conditions extending over some hundreds of miles. During very settled, warm anticyclonic weather (i.e., high pressure), usually weak signals from distant transmitters improve in strength. Another symptom during such conditions may be interference to the local transmitter resulting in co-channel ...https://en.wikipedia.org/wiki/Tropospheric_propagation
Injecting Sulfate Particles Into Stratosphere Won't Fully Offset Climate Change - Redorbit
As the reality and the impact of climate warming have become clearer in the last decade, researchers have looked for possible engineering solutions - such as removing carbon dioxide from the atmosphere or directing the sun's heat away from Earth - to help offset rising temperatures.. New University of Washington research demonstrates that one suggested method, injecting sulfate particles into the stratosphere, would likely achieve only part of the desired effect, and could carry serious, if unintended, consequences.. The lower atmosphere already contains tiny sulfate and sea salt particles, called aerosols, that reflect energy from the sun into space. Some have suggested injecting sulfate particles directly into the stratosphere to enhance the effect, and also to reduce the rate of future warming that would result from continued increases in atmospheric carbon dioxide.. But a UW modeling study shows that sulfate particles in the stratosphere will not necessarily offset all ...http://www.redorbit.com/news/science/1112462578/injecting-sulfate-particles-into-stratosphere-wont-fully-offset-climate-change/
Onset of the aerobic nitrogen cycle during the Great Oxidation Event<...
TY - JOUR. T1 - Onset of the aerobic nitrogen cycle during the Great Oxidation Event. AU - Zerkle,Aubrey L.. AU - Poulton,Simon W.. AU - Newton,Robert J.. AU - Mettam,Colin. AU - Claire,Mark W.. AU - Bekker,Andrey. AU - Junium,Christopher K.. PY - 2017/2/23. Y1 - 2017/2/23. N2 - The rise of oxygen on the early Earth (about 2.4 billion years ago) caused a reorganization of marine nutrient cycles, including that of nitrogen, which is important for controlling global primary productivity. However, current geochemical records lack the temporal resolution to address the nature and timing of the biogeochemical response to oxygenation directly. Here we couple records of ocean redox chemistry with nitrogen isotope (15N/14N) values from approximately 2.31-billion-year-old shales of the Rooihoogte and Timeball Hill formations in South Africa, deposited during the early stages of the first rise in atmospheric oxygen on the Earth (the Great Oxidation Event). Our data fill a gap of about 400 million years in ...https://experts.syr.edu/en/publications/onset-of-the-aerobic-nitrogen-cycle-during-the-great-oxidation-ev
CO Meeting Organizer EGU2011
Researchers are invited to present novel scientific results from mid- and long-term observational time series from various measurements networks such as Global Atmosphere Watch (GAW), European Monitoring and Evaluation Programme (EMEP), Network for the Detection of Atmospheric Composition Change (NDACC), Southern Hemisphere Additional Ozonesondes (SHADOZ), Advanced Global Atmospheric Gases Experiment (AGAGE), National Oceanic and Atmospheric Administration (NOAA), regular airborne (e.g. MOZAIC, CARIBIC) and other campaigns as well as satellite data and model simulations. Data relevant to tropospheric and stratospheric composition, in particular related to ozone depletion, climate change and air quality as well as firn data on past atmospheric composition are welcome. We welcome contributions from multi-year modeling studies and inter-comparison exercises which address tropospheric or stratospheric composition changes, carried out in the framework of international projects (e.g. GEOMON, MACC) ...http://meetingorganizer.copernicus.org/EGU2011/session/6394
The mobile NDSC-Lidar MARL: Measurements of Aerosol and Clouds in the northern and southern hemisphere. - ePIC
AWI's MARL-instrument is a mobile backscatter lidar that is used at various locations as well as aboard the research vessel Polarstern to measure Aerosol and clouds in the upper troposphere and lower stratosphere. In 2000 two field-experiments have been conducted within the European INCA 2000-project (Interhemispheric differences in cirrus cloud properties by anthropogenic emissions). The first one took place in the southern hemispheric midlatitudes, in Punta Arenas/Chile (53.12°S, 70.88°W) and the second campaign followed in September 2000 in Prestwick /Scotland (55.51°N, 4.60°W). The main objective of these activities was to collect Lidar data on cirrus clouds from clean (Punta Arenas) and polluted (Prestwick) areas. During the four weeks of the campaigns, around 80 h of Lidar measure-ments were gathered at each location, covering different types of cirrus clouds as well as background aerosols. A comparison of the two datasets reveals similarities as well as differ-ences in the measured ...http://epic.awi.de/6382/
7(a) Atmospheric Composition
The fifth most abundant gas in the atmosphere is carbon dioxide. The volume of this gas has increased by over 35% in the last three hundred years (see Figure 7a-1). This increase is primarily due to human induced burning from fossil fuels, deforestation, and other forms of land-use change. Carbon dioxide is an important greenhouse gas. The human-caused increase in its concentration in the atmosphere has strengthened the greenhouse effect and has definitely contributed to global warming over the last 100 years. Carbon dioxide is also naturally exchanged between the atmosphere and life through the processes of photosynthesis and respiration.. Methane is a very strong greenhouse gas. Since 1750, methane concentrations in the atmosphere have increased by more than 150%. The primary sources for the additional methane added to the atmosphere (in order of importance) are: rice cultivation; domestic grazing animals; termites; ...http://www.physicalgeography.net/fundamentals/7a.html
Cloud - Wikipedia
In meteorology, a cloud is an aerosol comprising a visible mass of minute liquid droplets, frozen crystals, or particles suspended in the atmosphere above the surface of a planetary body. The droplets and crystals may be made of water or various chemicals. On Earth, clouds are formed as a result of saturation of the air when it is cooled to its dew point, or when it gains sufficient moisture (usually in the form of water vapor) from an adjacent source to raise the dew point to the ambient temperature. They are seen in the Earth's homosphere (which includes the troposphere, stratosphere, and mesosphere). Nephology is the science of clouds which is undertaken in the cloud physics branch of meteorology. There are two methods of naming clouds in their respective layers of the atmosphere; Latin and common. Cloud types in the troposphere, the atmospheric layer closest to Earth's surface, have Latin names due to the universal adaptation of Luke Howard's nomenclature. Formally ...https://en.wikipedia.org/wiki/Cloud
Abstract. Sulfate geoengineering (SG), made by sustained injection of SO2 in the tropical lower stratosphere, may impact the CH4 abundance through several photochemical mechanisms affecting tropospheric OH and hence the methane lifetime. (a) The reflection of incoming solar radiation increases the planetary albedo and cools the surface, with a tropospheric H2O decrease. (b) The tropospheric UV budget is upset by the additional aerosol scattering and stratospheric ozone changes: the net effect is meridionally not uniform, with a net decrease in the tropics, thus producing less tropospheric O(1D). (c) The extratropical downwelling motion from the lower stratosphere tends to increase the sulfate aerosol surface area density available for heterogeneous chemical reactions in the mid-to-upper troposphere, thus reducing the amount of NOx and O3 production. (d) The tropical lower stratosphere is warmed by solar and planetary radiation absorption by the aerosols. The heating rate perturbation is highly ...https://www.atmos-chem-phys.net/17/11209/2017/acp-17-11209-2017.html
The Week That Was
2. The Ongoing Debate about Satellite Temperature Data; Part1. More than a decade ago, Roy Spencer and John Christy realized that the data from the microwave-sounding unit (MSU) on weather satellites could be used to measure long-term temperature trends of the Earth's atmosphere. Their analysis produced surprisingly low values since 1979 - at first, a slightly negative and, more recently, a slightly positive trend for the troposphere. These MSU results derived by the University of Alabama (Huntsville) group are in good agreement with independently derived trends from radiosondes carried in weather balloons.. Their results have caused - and continue to cause -- great consternation among supporters of the greenhouse-warming hypothesis. For not only do the MSU-UAH trends disagree with the warming trend shown by (global mean) surface data (from weather stations and from sea surface temperatures --- SST), but they also contradict the GH models -- all of which show the troposphere warming more ...http://www.sepp.org/twtwfiles/2004/May%208.htm
Eruption column - Wikipedia
The column will stop rising once it attains an altitude where it is more dense than the surrounding air. Several factors control the height that an eruption column can reach.. Intrinsic factors include the diameter of the erupting vent, the gas content of the magma, and the velocity at which it is ejected. Extrinsic factors can be important, with winds sometimes limiting the height of the column, and the local thermal temperature gradient also playing a role. The atmospheric temperature in the troposphere normally decreases by about 6-7 K/km, but small changes in this gradient can have a large effect on the final column height. Theoretically, the maximum achievable column height is thought to be about 55 km (34 mi). In practice, column heights ranging from about 2-45 km (1.2-28.0 mi) are seen.. Eruption columns over 10-15 km (6.2-9.3 mi) high break through the tropopause and inject ash and aerosols into the stratosphere. Ash and aerosols in the troposphere are quickly removed by rain and other ...https://en.wikipedia.org/wiki/Eruption_column
GMD - Abstract - Compiled records of carbon isotopes in atmospheric CO2 for historical simulations in CMIP6
Abstract. The isotopic composition of carbon (Δ14C and δ13C) in atmospheric CO2 and in oceanic and terrestrial carbon reservoirs is influenced by anthropogenic emissions and by natural carbon exchanges, which can respond to and drive changes in climate. Simulations of 14C and 13C in the ocean and terrestrial components of Earth system models (ESMs) present opportunities for model evaluation and for investigation of carbon cycling, including anthropogenic CO2 emissions and uptake. The use of carbon isotopes in novel evaluation of the ESMs' component ocean and terrestrial biosphere models and in new analyses of historical changes may improve predictions of future changes in the carbon cycle and climate system. We compile existing data to produce records of Δ14C and δ13C in atmospheric CO2 for the historical period 1850-2015. The primary motivation for this compilation is to provide the atmospheric boundary condition for historical simulations in the Coupled Model Intercomparison Project 6 ...https://www.geosci-model-dev.net/10/4405/2017/
Methane hydrates: May 2013
Loss of the integrity of the permafrost is particularly threatening in the Arctic, where the sea ice looks set to disappear within years, resulting in huge albedo changes in summer. Decrease of surface reflectivity results in increases in absorption of energy from sunlight and decreases in shortwave radiation in the atmosphere. The latter results in lower photo-dissociation rates of tropospheric gases. Photo-dissociation of the ozone molecule is the major process that leads to the production of OH (hydroxyl radical), the main oxidizing (i.e., cleansing) gas species in the troposphere. A 2009 NASA study projects this to lead to a decrease in OH concentrations and a weakening of the oxidizing capacity of the Arctic troposphere, further increasing the vulnerability of the Arctic to warming in case of additional methane releases ...http://methane-hydrates.blogspot.ca/2013/05/