Showing papers by "Kevin J. Noone published in 2006"

Science Plan and Implementation Strategy

Abstract: This Science Plan and Implementation Strategy sets out the research agenda for the second phase of IGBP The document describes the IGBP strategy for producing high quality, unbiased, credible, fundamental scientific research in the area of global change: a strategy centered on ten projects, to be carried out by the several thousand scientists worldwide who are part of the IGBP network Further, the document describes how the organization will communicate the results of this research to different audiences, in order to realize its vision: "to provide scientific knowledge to improve the sustainability of the living Earth"

Aerosol direct radiative effects over the northwest Atlantic, northwest Pacific, and North Indian Oceans: estimates based on in-situ chemical and optical measurements and chemical transport modeling

Abstract: The largest uncertainty in the radiative forcing of climate change over the industrial era is that due to aerosols, a substantial fraction of which is the uncertainty associated with scattering and absorption of shortwave (solar) radiation by anthropogenic aerosols in cloud-free conditions (IPCC, 2001). Quantifying and reducing the uncertainty in aerosol influences on climate is critical to understanding climate change over the industrial period and to improving predic- tions of future climate change for assumed emission scenar- ios. Measurements of aerosol properties during major field campaigns in several regions of the globe during the past decade are contributing to an enhanced understanding of at- mospheric aerosols and their effects on light scattering and climate. The present study, which focuses on three regions

Measurement of Ambient, Interstitial, and Residual Aerosol Particles on a Mountaintop Site in Central Sweden using an Aerosol Mass Spectrometer and a CVI

Abstract: The Aerodyne aerosol mass spectrometer (Q-AMS) was coupled with a counterflow virtual impactor (CVI) for the first time to measure cloud droplet residuals of warm tropospheric clouds on Mt. Areskutan in central Sweden in July 2003. Operating the CVI in different operational modes generated mass concentration and species-resolved mass distribution data for non-refractory species of the ambient, interstitial, and residual aerosol. The ambient aerosol measurements revealed that the aerosol at the site was mainly influenced by long-range transport and regional photochemical generation of nitrate and organic aerosol components. Four different major air masses were identified for the time interval of the experiment. While two air masses that approached the site from northeastern Europe via Finland showed very similar aerosol composition, the other two air masses from polar regions and the British Islands had a significantly different composition. During cloud events the larger aerosol particles were found to be activated into cloud droplets. On a mass basis the activation cut-off diameter was approximately 150 nm for nitrate and organics dominated particles and 200 nm for sulfate dominated particles. Generally nitrate and organics were found to be activated into cloud droplets with higher efficiency than sulfate. While a significant fraction of the nitrate in ambient particles was organic nitrates or nitrogen-containing organic species, the nitrate found in the cloud droplet residuals was mainly ammonium nitrate. After passage of clouds the ambient aerosol size distribution had shifted to smaller particle sizes due to the predominantly activation of larger aerosol particles without a significant change in the relative composition of the ambient aerosol.