IMPACTS OF FAIR-WEATHER CUMULUS CLOUDS, BAY BREEZES, AND LAND USE ON URBAN AIR QUALITY AND CLIMATE

Simple item page
dc.contributor.advisorAllen, Dale Jen_US
dc.contributor.advisorDickerson, Russell Ren_US
dc.contributor.authorLoughner, Christopher Paulen_US
dc.contributor.departmentAtmospheric and Oceanic Sciencesen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2011-10-08T06:02:52Z
dc.date.available2011-10-08T06:02:52Z
dc.date.issued2011en_US
dc.description.abstractFair-weather cumulus clouds, bay breezes, and land use influence air quality and climate. The impacts of urban land surface changes and model resolution on fair-weather cumulus clouds, bay breezes, air quality, and climate are examined. As model resolution increases, more pollutants are transported aloft through fair-weather cumulus clouds causing an increase in the rate of sulfur dioxide conversion to sulfate aerosols and an increase in boundary layer venting. As model resolution increases, a larger temperature gradient develops along the shoreline of the Chesapeake Bay causing the bay breeze to form sooner, push farther inland, and loft more pollutants upward. This stronger bay breeze results in low-level convergence, a buildup of near surface ozone over land and a decrease in the land-to-sea flux of ozone and ozone precursors. Also, an examination of the sensitivity of sulfur dioxide to sulfate conversion to different model cloud parameters shows the importance of accurately simulating clouds to obtain accurate sulfate concentrations. To analyze the impact of urbanization on the atmosphere, an urban tree parameterization is developed for the Weather Research and Forecasting model coupled with an urban canopy model (WRF-UCM) to determine how urban trees can dampen the urban heat island (UHI). Adding vegetation decreases the (subgrid-scale) surface air temperature due to tree shading and evapotranspiration. The impact of building height on the UHI shows that shorter urban buildings have higher daytime surface temperatures due to less shading and lower nighttime temperatures due to less longwave radiative trapping in urban street canyons. The WRF-UCM with urban trees is utilized with an air quality model to investigate how urban vegetation changes impact air quality. Cooling due to planting urban trees is expected to improve air quality. However, for one case study that does not include anthropogenic emissions reductions due to cooling from increased vegetation, adding trees in the model results in higher ground level ozone concentrations due to a shallower planetary boundary layer and more pollutants converging near a stronger bay breeze near Baltimore, MD. Future work incorporating changes in anthropogenic emissions with changes in urban vegetation will help quantify how urban trees impact air quality.en_US
dc.identifier.urihttp://hdl.handle.net/1903/11967
dc.subject.pqcontrolledAtmospheric sciencesen_US
dc.subject.pqcontrolledAtmospheric chemistryen_US
dc.subject.pqcontrolledMeteorologyen_US
dc.subject.pquncontrolledBay breezeen_US
dc.subject.pquncontrolledFair-weather cumulus cloudsen_US
dc.subject.pquncontrolledOzoneen_US
dc.subject.pquncontrolledSulfur dioxideen_US
dc.subject.pquncontrolledUrban heat islanden_US
dc.subject.pquncontrolledUrban vegetationen_US
dc.titleIMPACTS OF FAIR-WEATHER CUMULUS CLOUDS, BAY BREEZES, AND LAND USE ON URBAN AIR QUALITY AND CLIMATEen_US
dc.typeDissertationen_US

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Loughner_umd_0117E_12528.pdf
Size:
2.55 MB
Format:
Adobe Portable Document Format
Download

Collections

UMD Theses and Dissertations
Atmospheric & Oceanic Science Theses and Dissertations