scholarly journals Influence of slightly soluble organics on aerosol activation

2005 ◽  
Vol 110 (D6) ◽  
pp. n/a-n/a ◽  
Author(s):  
Hayder Abdul-Razzak ◽  
Steven J. Ghan
Keyword(s):  
Aerosol Activation

LANFEX: A Field and Modeling Study to Improve Our Understanding and Forecasting of Radiation Fog

2018 ◽  
Vol 99 (10) ◽  
pp. 2061-2077 ◽  
Author(s):  
J. D. Price ◽  
S. Lane ◽  
I. A. Boutle ◽  
D. K. E. Smith ◽  
T. Bergot ◽  
...  
Keyword(s):  
Numerical Study ◽  
Weather Prediction ◽  
Weather Forecast ◽  
Radiation Fog ◽  
Complex Interactions ◽  
Early Results ◽  
Weather Phenomenon ◽  
Forecast Models ◽  
The Difference ◽  
Aerosol Activation

AbstractFog is a high-impact weather phenomenon affecting human activity, including aviation, transport, and health. Its prediction is a longstanding issue for weather forecast models. The success of a forecast depends on complex interactions among various meteorological and topographical parameters; even very small changes in some of these can determine the difference between thick fog and good visibility. This makes prediction of fog one of the most challenging goals for numerical weather prediction. The Local and Nonlocal Fog Experiment (LANFEX) is an attempt to improve our understanding of radiation fog formation through a combined field and numerical study. The 18-month field trial was deployed in the United Kingdom with an extensive range of equipment, including some novel measurements (e.g., dew measurement and thermal imaging). In a hilly area we instrumented flux towers in four adjacent valleys to observe the evolution of similar, but crucially different, meteorological conditions at the different sites. We correlated these with the formation and evolution of fog. The results indicate new quantitative insight into the subtle turbulent conditions required for the formation of radiation fog within a stable boundary layer. Modeling studies have also been conducted, concentrating on high-resolution forecast models and research models from 1.5-km to 100-m resolution. Early results show that models with a resolution of around 100 m are capable of reproducing the local-scale variability that can lead to the onset and development of radiation fog, and also have identified deficiencies in aerosol activation, turbulence, and cloud micro- and macrophysics, in model parameterizations.

scholarly journals Size-dependent aerosol activation at the high-alpine site Jungfraujoch (3580 m asl)

Tellus B ◽  
2002 ◽  
Vol 54 (1) ◽  
pp. 82-95 ◽  
Author(s):  
S. Henning ◽  
E. Weingartner ◽  
S. Schmidt ◽  
M. Wendisch ◽  
H. W. Gäggeler ◽  
...  
Keyword(s):  
Size Dependent ◽  
Aerosol Activation

scholarly journals A parameterization of aerosol activation: 1. Single aerosol type

1998 ◽  
Vol 103 (D6) ◽  
pp. 6123-6131 ◽  
Author(s):  
Hayder Abdul-Razzak ◽  
Steven J. Ghan ◽  
Carlos Rivera-Carpio
Keyword(s):  
Aerosol Activation ◽  
Aerosol Type

scholarly journals A parameterization of aerosol activation: 2. Multiple aerosol types

2000 ◽  
Vol 105 (D5) ◽  
pp. 6837-6844 ◽  
Author(s):  
Hayder Abdul-Razzak ◽  
Steven J. Ghan
Keyword(s):  
Aerosol Activation ◽  
Aerosol Types

scholarly journals Incorporating an advanced aerosol activation parameterization into WRF-CAM5: Model evaluation and parameterization intercomparison

2015 ◽  
Vol 120 (14) ◽  
pp. 6952-6979 ◽  
Author(s):  
Yang Zhang ◽  
Xin Zhang ◽  
Kai Wang ◽  
Jian He ◽  
L. Ruby Leung ◽  
...  
Keyword(s):  
Model Evaluation ◽  
Aerosol Activation

scholarly journals Incorporation of advanced aerosol activation treatments into CESM/CAM5: model evaluation and impacts on aerosol indirect effects

2014 ◽  
Vol 14 (14) ◽  
pp. 7485-7497 ◽  
Author(s):  
B. Gantt ◽  
J. He ◽  
X. Zhang ◽  
Y. Zhang ◽  
A. Nenes
Keyword(s):  
Indirect Effects ◽  
Radiative Forcing ◽  
Cloud Condensation Nuclei ◽  
Condensation Nuclei ◽  
Activation Kinetics ◽  
Aerosol Cloud ◽  
Model Version ◽  
Cloud Properties ◽  
Aerosol Cloud Interactions ◽  
Aerosol Activation

Abstract. One of the greatest sources of uncertainty in the science of anthropogenic climate change is from aerosol–cloud interactions. The activation of aerosols into cloud droplets is a direct microphysical linkage between aerosols and clouds; parameterizations of this process link aerosol with cloud condensation nuclei (CCN) and the resulting indirect effects. Small differences between parameterizations can have a large impact on the spatiotemporal distributions of activated aerosols and the resulting cloud properties. In this work, we incorporate a series of aerosol activation schemes into the Community Atmosphere Model version 5.1.1 within the Community Earth System Model version 1.0.5 (CESM/CAM5) which include factors such as insoluble aerosol adsorption and giant cloud condensation nuclei (CCN) activation kinetics to understand their individual impacts on global-scale cloud droplet number concentration (CDNC). Compared to the existing activation scheme in CESM/CAM5, this series of activation schemes increase the computation time by ~10% but leads to predicted CDNC in better agreement with satellite-derived/in situ values in many regions with high CDNC but in worse agreement for some regions with low CDNC. Large percentage changes in predicted CDNC occur over desert and oceanic regions, owing to the enhanced activation of dust from insoluble aerosol adsorption and reduced activation of sea spray aerosol after accounting for giant CCN activation kinetics. Comparison of CESM/CAM5 predictions against satellite-derived cloud optical thickness and liquid water path shows that the updated activation schemes generally improve the low biases. Globally, the incorporation of all updated schemes leads to an average increase in column CDNC of 150% and an increase (more negative) in shortwave cloud forcing of 12%. With the improvement of model-predicted CDNCs and better agreement with most satellite-derived cloud properties in many regions, the inclusion of these aerosol activation processes should result in better predictions of radiative forcing from aerosol–cloud interactions.

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