Quantifying the Effects of Aerosols on Climate, and Their Behaviour in the Atmosphere
Lead Research Organisation:
University of East Anglia
Department Name: Environmental Sciences
Abstract
Summary for General Audience Atmospheric aerosols - small particles suspended in the air - include seasalt (from breaking waves), wind-blown dust, and sulphates and organic compounds from both natural and anthropogenic sources. Aerosols can affect the earth's budget of solar radiation, first, by scattering and absorbing incoming solar and outgoing terrestrial radiation (the direct effect). Second, aerosols can affect the optical properties of clouds - which both scatter solar radiation back to space, and absorb outgoing long wave radiation - by changing the numbers of water droplets present (the indirect effect). The total magnitude of the aerosol effect on the surface temperature of the earth is similar to that of the greenhouse gases (mainly CO2), but is believed to be a net cooling rather than warming. However, the exact size of the effect is very uncertain. Aerosol particles also affect human health and provide surfaces for chemical reactions to take place on, many of which are important in determining the concentration of surface ozone which is harmful. The U.K. Meteorological Office carries out climate research and is the joint leader of a programme to build and evaluate a new global computer model suitable for a range of topics in climate and environmental change research. One of the key tasks is to improve the representation of atmospheric aerosols and their effects in the model. Important aerosol properties include the uptake of water by the aerosol particles in response to atmospheric relative humidity and temperature changes, the size of the aerosol particles, and the partitioning between the aerosols and surrounding gas phase of volatile compounds such as ammonia, nitric acid, and some organic compounds. Improving the treatment of aerosols in the computer model is an essential step to representing both the direct and indirect aerosol effects more accurately, and to making improved climate change predictions, and formulating effective public policy for adaptation and remediation. This project assists the Met Office in this task. The formation, properties, and behaviour of atmospheric aerosols are currently the subject of active investigation in the laboratory, by field measurement campaigns, and by modellers around the world. The Met Office does not have expertise in the detailed thermodynamics of gas/aerosol which can be used to develop and test new aerosol schemes that can be incorporated into their climate model. The primary purpose of this knowledge transfer project is to address this gap by providing web-based tools incorporating state-of-the-art aerosol models developed by us over a period of more than 5 years. These embody the results of internationally recognized research into the behaviour of the components of tropospheric and stratospheric aerosol systems. They will enable the Met Office to evaluate and test representation of aerosol properties in their global climate and other models, guide their future development, and ultimately reduce the uncertainties associated with the aerosol influence on climate change. These web-based tools can be accessed freely, and our past experience demonstrates that they are likely to be used in aerosol science research and teaching worldwide.
Publications
Clegg SL
(2011)
Densities and apparent molar volumes of atmospherically important electrolyte solutions. 2. The systems H(+)-HSO4(-)-SO4(2-)-H2O from 0 to 3 mol kg(-1) as a function of temperature and H(+)-NH4(+)-HSO4(-)-SO4)2-)-H2O from 0 to 6 mol kg(-1) at 25 °C using a Pitzer ion interaction model, and NH4HSO4-H2O and (NH4)3H(SO4)2-H2O over the entire concentration range.
in The journal of physical chemistry. A
Clegg SL
(2011)
Densities and apparent molar volumes of atmospherically important electrolyte solutions. 1. The solutes H2SO4, HNO3, HCl, Na2SO4, NaNO3, NaCl, (NH4)2SO4, NH4NO3, and NH4Cl from 0 to 50 °C, including extrapolations to very low temperature and to the pure liquid state, and NaHSO4, NaOH, and NH3 at 25 °C.
in The journal of physical chemistry. A
Dutcher C
(2012)
Statistical Mechanics of Multilayer Sorption: 2. Systems Containing Multiple Solutes
in The Journal of Physical Chemistry C
Dutcher C
(2011)
Statistical Mechanics of Multilayer Sorption: Extension of the Brunauer-Emmett-Teller (BET) and Guggenheim-Anderson-de Boer (GAB) Adsorption Isotherms
in The Journal of Physical Chemistry C
Dutcher CS
(2010)
Surface tensions of inorganic multicomponent aqueous electrolyte solutions and melts.
in The journal of physical chemistry. A
Ge X
(2011)
Atmospheric amines - Part I. A review
in Atmospheric Environment
Ge X
(2011)
Atmospheric amines - Part II. Thermodynamic properties and gas/particle partitioning
in Atmospheric Environment
Hargreaves G
(2010)
Measurements of the Equilibrium Size of Supersaturated Aqueous Sodium Chloride Droplets at Low Relative Humidity Using Aerosol Optical Tweezers and an Electrodynamic Balance
in The Journal of Physical Chemistry A
Description | We have developed the internationally recognised reference chemical model for the calculation of gas/liquid/solid partitioning in atmospheric particles and droplets. |
Exploitation Route | The model is used for the interpretation of laboratory experiments related to atmospheric chemistry, and as a reference for the development of large scale (regional, global) atmospheric air quality and climate computer models. |
Sectors | Environment |
Description | --- |
Amount | $300,000 (USD) |
Organisation | Electric Power Research Institute (EPRI) |
Sector | Charity/Non Profit |
Country | United States |
Start | 07/2011 |
End | 12/2013 |
Description | International Opportunities Fund |
Amount | £40,000 (GBP) |
Organisation | Natural Environment Research Council |
Sector | Public |
Country | United Kingdom |
Start | 01/2016 |
End | 12/2017 |
Title | E-AIM |
Description | Extended AIM Aerosol Thermodynamics Model: A community model for calculating gas/liquid/solid partitioning in aerosol systems containing inorganic and organic components and water, and solute and solvent activities in aqueous solutions and liquid mixtures. |
Type Of Material | Computer model/algorithm |
Year Produced | 2011 |
Provided To Others? | Yes |
Impact | See section elsewhere providing the same info. |
URL | http://www.aim.env.uea.ac.uk/aim/aim.php |
Description | Collaboration with the Air Quality Research Centre (UC Davis) |
Organisation | University of California, Davis |
Department | Air Quality Research Centre |
Country | United States |
Sector | Academic/University |
PI Contribution | Over the period of this project I have been a member of the Air Quality Research Centre at the University of California, and the work has resulted in new projects funded by the National Oceanographic and Atmospheric Administration, National Science Foundation, Department of Energy, and Electric Power Research Institute in the USA. The results of two of these projects have added substantially to the website which is one of the main outputs of this work. |
Start Year | 2011 |
Description | Linking Aerosol Physical Chemistry and Atmospheric Effects via kappa-Kohler Theory |
Organisation | North Carolina State University |
Country | United States |
Sector | Academic/University |
PI Contribution | I contributed the use of the thermodynamic model and website to this new project, and expanded the website to add new methods and calculations that are part of this collaboration. |
Collaborator Contribution | Petters (NC State University, USA) contributed expertise in kappa-Kohler theory and will curate a database of "kappa" values, used by atmospheric scientists to estimate the hygroscopic properties of atmospheric particles. Reid (University of Bristol) contributes experimental data and quantitative insights into particle behaviour. |
Impact | Expansion of E-AIM website pages to include calculations based upon methods used in this project will be done in March 2017 (http://www.aim.env.uea.ac.uk/aim/aim.php). |
Start Year | 2015 |
Description | Linking Aerosol Physical Chemistry and Atmospheric Effects via kappa-Kohler Theory |
Organisation | University of Bristol |
Department | Faculty of Engineering |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | I contributed the use of the thermodynamic model and website to this new project, and expanded the website to add new methods and calculations that are part of this collaboration. |
Collaborator Contribution | Petters (NC State University, USA) contributed expertise in kappa-Kohler theory and will curate a database of "kappa" values, used by atmospheric scientists to estimate the hygroscopic properties of atmospheric particles. Reid (University of Bristol) contributes experimental data and quantitative insights into particle behaviour. |
Impact | Expansion of E-AIM website pages to include calculations based upon methods used in this project will be done in March 2017 (http://www.aim.env.uea.ac.uk/aim/aim.php). |
Start Year | 2015 |
Title | Extended Aerosol Inorganics Website |
Description | The web-based tools are a set of community models for calculating gas/liquid/solid partitioning in aerosol systems containing inorganic and organic components and water, and solute and solvent activities in aqueous solutions and liquid mixtures. |
Type Of Technology | Webtool/Application |
Year Produced | 2011 |
Impact | The models/site is regarded as a reference by the world aerosol science community, and is used for benchmarking/developing regional air quality models and interpreting laboratory data. Over 32,000 individually entered calculations were carried out last year on the site. |
URL | http://www.aim.env.uea.ac.uk/aim/aim.php |