Institution
Pacific Northwest National Laboratory
Facility•Richland, Washington, United States•
About: Pacific Northwest National Laboratory is a facility organization based out in Richland, Washington, United States. It is known for research contribution in the topics: Catalysis & Aerosol. The organization has 11581 authors who have published 27934 publications receiving 1120489 citations. The organization is also known as: PNL & PNNL.
Topics: Catalysis, Aerosol, Mass spectrometry, Population, Ion
Papers published on a yearly basis
Papers
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TL;DR: In this article, the chemical composition of secondary organic aerosol (SOA) particles, formed by the dark ozonolysis of α-pinene, was characterized by a high-resolution time-of-flight aerosol mass spectrometer.
Abstract: . The chemical composition of secondary organic aerosol (SOA) particles, formed by the dark ozonolysis of α-pinene, was characterized by a high-resolution time-of-flight aerosol mass spectrometer. The experiments were conducted using a continuous-flow chamber, allowing the particle mass loading and chemical composition to be maintained for several days. The organic portion of the particle mass loading was varied from 0.5 to >140 μg/m3 by adjusting the concentration of reacted α-pinene from 0.9 to 91.1 ppbv. The mass spectra of the organic material changed with loading. For loadings below 5 μg/m3 the unit-mass-resolution m/z 44 (CO2+) signal intensity exceeded that of m/z 43 (predominantly C2H3O+), suggesting more oxygenated organic material at lower loadings. The composition varied more for lower loadings (0.5 to 15 μg/m3) compared to higher loadings (15 to >140 μg/m3). The high-resolution mass spectra showed that from >140 to 0.5 μg/m3 the mass percentage of fragments containing carbon and oxygen (CxHyOz+) monotonically increased from 48% to 54%. Correspondingly, the mass percentage of fragments representing CxHy+ decreased from 52% to 46%, and the atomic oxygen-to-carbon ratio increased from 0.29 to 0.45. The atomic ratios were accurately parameterized by a four-product basis set of decadal volatility (viz. 0.1, 1.0, 10, 100 μg/m3) employing products having empirical formulas of C1H1.32O0.48, C1H1.36O0.39, C1H1.57O0.24, and C1H1.76O0.14. These findings suggest considerable caution is warranted in the extrapolation of laboratory results that were obtained under conditions of relatively high loading (i.e., >15 μg/m3) to modeling applications relevant to the atmosphere, for which loadings of 0.1 to 20 μg/m3 are typical. For the lowest loadings, the particle mass spectra resembled observations reported in the literature for some atmospheric particles.
251 citations
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TL;DR: In this article, a description of the integrated representation for the cloud processes in the Community Atmosphere Model, version 5 (CAM5) is provided. But the model is not suitable for the simulation of marine stratocumulus.
Abstract: This paper provides a description of the integrated representation for the cloud processes in the Community Atmosphere Model, version 5 (CAM5). CAM5 cloud parameterizations add the following unique characteristics to previous versions: 1) a cloud macrophysical structure with horizontally nonoverlapped deep cumulus, shallow cumulus, and stratus in each grid layer, where each of which has its own cloud fraction, and mass and number concentrations for cloud liquid droplets and ice crystals; 2) stratus–radiation–turbulence interactions that allow CAM5 to simulate marine stratocumulus solely from grid-mean relative humidity without relying on a stability-based empirical formula; 3) prognostic treatment of the number concentrations of stratus liquid droplets and ice crystals, with activated aerosols and detrained in-cumulus condensates as the main sources and with evaporation, sedimentation, and precipitation of stratus condensate as the main sinks; and 4) radiatively active cumulus and snow. By imposin...
251 citations
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TL;DR: In this paper, the authors extended the theory of foam mobilization at a critical pressure gradient to a variety of porous media, including bead and sandpacks, and showed that foam generation can be accelerated by a critical injection velocity or pressure gradient in homogeneous porous media with surfactant present.
251 citations
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TL;DR: In this paper, a two-moment cloud microphysics scheme for a general circulation model (GCM) is presented and evaluated relative to observations, which produces reasonable representations of cloud particle size and number concentration when compared to observations.
Abstract: The global performance of a new two-moment cloud microphysics scheme for a general circulation model (GCM) is presented and evaluated relative to observations. The scheme produces reasonable representations of cloud particle size and number concentration when compared to observations, and it represents expected and observed spatial variations in cloud microphysical quantities. The scheme has smaller particles and higher number concentrations over land than the standard bulk microphysics in the GCM and is able to balance the top-of-atmosphere radiation budget with 60% the liquid water of the standard scheme, in better agreement with retrieved values. The new scheme diagnostically treats both the mixing ratio and number concentration of rain and snow, and it is therefore able to differentiate the two key regimes, consisting of drizzle in shallow, warm clouds and larger rain drops in deeper cloud systems. The modeled rain and snow size distributions are consistent with observations.
251 citations
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TL;DR: In this paper, carbon and hydrogen isotopic signatures were used to estimate the relative contribution of abiogenic versus microbial hydrocarbon gases at four underground sites in Precambrian Shield rocks in Canada and South Africa.
251 citations
Authors
Showing all 11848 results
Name | H-index | Papers | Citations |
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Yi Cui | 220 | 1015 | 199725 |
Derek R. Lovley | 168 | 582 | 95315 |
Xiaoyuan Chen | 149 | 994 | 89870 |
Richard D. Smith | 140 | 1180 | 79758 |
Taeghwan Hyeon | 139 | 563 | 75814 |
Jun Liu | 138 | 616 | 77099 |
Federico Capasso | 134 | 1189 | 76957 |
Jillian F. Banfield | 127 | 562 | 60687 |
Mary M. Horowitz | 127 | 557 | 56539 |
Frederick R. Appelbaum | 127 | 677 | 66632 |
Matthew Jones | 125 | 1161 | 96909 |
Rainer Storb | 123 | 905 | 58780 |
Zhifeng Ren | 122 | 695 | 71212 |
Wei Chen | 122 | 1946 | 89460 |
Thomas E. Mallouk | 122 | 549 | 52593 |