Direct climate responses to dust shortwave and longwave radiative forcing （RF） are studied using the NCAR Community Atmosphere Model Version 3 （CAM3）. The simulated RF at the top of the atmosphere （TOA） is-0.45 ...Direct climate responses to dust shortwave and longwave radiative forcing （RF） are studied using the NCAR Community Atmosphere Model Version 3 （CAM3）. The simulated RF at the top of the atmosphere （TOA） is-0.45 W m-2 in the solar spectrum and ＋0.09 W m-2 in the thermal spectrum on a global average. The magnitude of surface RF is larger than the TOA forcing, with global mean shortwave forcing of-1.76 W m-2 and longwave forcing of ＋0.31 W m-2 . As a result, dust aerosol causes the absorption of 1.1 W m-2 in the atmosphere. The RF of dust aerosol is predicted to lead to a surface cooling of 0.5 K over the Sahara Desert and Arabian Peninsula. In the meantime, the upper troposphere is predicted to become warmer because of the absorption by dust. These changes in temperature lead to a more stable atmosphere, which results in increases in surface humidity. The upward sensible and latent heat fluxes at the surface are reduced, largely balancing the surface energy loss caused by the backscattering and absorption of dust aerosol. Precipitation is predicted to decrease moderately on a global scale.展开更多
The marine and coastal intake filtration device is mainly used to filter out the salt spray aerosol particles. So, the laboratory studies of the intake filtration device need to simulate the salt spray aerosols state ...The marine and coastal intake filtration device is mainly used to filter out the salt spray aerosol particles. So, the laboratory studies of the intake filtration device need to simulate the salt spray aerosols state of the ocean environment. But the distribution of ocean salt spray aerosol particle of diameter is very wide, so the simulation device of salt spray aersol should produce a variety of salt spray aerosol particles. The paper is to mainly study the influencing factors of salt spray aerosol device to produce different particles diameter. And the investigation and study mainly include two aspects: numerical simulation and experimental study.展开更多
Contaminated or infected patients present a risk of cross-contamination for emergency responders, attending medical personnel and medical facilities as they enter a treatment facility. The controlled conditions of an ...Contaminated or infected patients present a risk of cross-contamination for emergency responders, attending medical personnel and medical facilities as they enter a treatment facility. The controlled conditions of an aerosol test chamber are required to examine factors of contamination, decontamination, and cross-contamination. This study presents the design, construction, and a method for characterizing an aerosol test chamber for a full-sized manikin on a standard North Atlantic Treaty Organization litter. The methodology combined air velocity measurements, aerosol particle counts and size distributions, and computational fluid dynamics modeling to describe the chamber’s performance in three dimensions. This detailed characterization facilitates future experimental design by predicting chamber performance for a variety of patient-focused research.展开更多
The tapered element oscillating microbalance with filter dynamics measurement system （TEOM-FDMS） is an instrument commonly employed by the French air quality monitoring network. This instrument is currently calibrat...The tapered element oscillating microbalance with filter dynamics measurement system （TEOM-FDMS） is an instrument commonly employed by the French air quality monitoring network. This instrument is currently calibrated with calibration weights traceable to SI but having value and mass differences between each of them that are not representative of real atmospheric particle mass measurements. Moreover, these calibration weights do not allow detection of any technical problems associated with either the TEOM-FDMS sampling system upstream of the mass measurement or the intrinsic TEOM-FDMS filtration system. Therefore, a calibration method was developed using a portable reference aerosol generator （PRAG） that produces known and stable particle mass concentrations over time. Here, we present the characterization of the PRAG system in terms of a reference range of particle masses between 30 - 10 and 3456 ± 83 μg at three sampling times. Its coupling with the TEOM-FDMS and a global comparison between the defined reference range of particle masses and the measured masses obtained with each TEOM-FDMS implicated in this study are also presented.展开更多
基金supported by the Key Project of Chinese Academy of Sciences under Grant KZCX2-YW-Q11-03supported by the National Basic Research Program of China ("973" program) under Grant2006CB403705+1 种基金the Key Project of Chinese Academy of Sciences under Grants KZCX2-YW-Q1-02, KZCX2-YW-205, and KZCX2-YW-219the National Natural Science Foundation of China under Grant No. 40631005
文摘Direct climate responses to dust shortwave and longwave radiative forcing （RF） are studied using the NCAR Community Atmosphere Model Version 3 （CAM3）. The simulated RF at the top of the atmosphere （TOA） is-0.45 W m-2 in the solar spectrum and ＋0.09 W m-2 in the thermal spectrum on a global average. The magnitude of surface RF is larger than the TOA forcing, with global mean shortwave forcing of-1.76 W m-2 and longwave forcing of ＋0.31 W m-2 . As a result, dust aerosol causes the absorption of 1.1 W m-2 in the atmosphere. The RF of dust aerosol is predicted to lead to a surface cooling of 0.5 K over the Sahara Desert and Arabian Peninsula. In the meantime, the upper troposphere is predicted to become warmer because of the absorption by dust. These changes in temperature lead to a more stable atmosphere, which results in increases in surface humidity. The upward sensible and latent heat fluxes at the surface are reduced, largely balancing the surface energy loss caused by the backscattering and absorption of dust aerosol. Precipitation is predicted to decrease moderately on a global scale.
文摘The marine and coastal intake filtration device is mainly used to filter out the salt spray aerosol particles. So, the laboratory studies of the intake filtration device need to simulate the salt spray aerosols state of the ocean environment. But the distribution of ocean salt spray aerosol particle of diameter is very wide, so the simulation device of salt spray aersol should produce a variety of salt spray aerosol particles. The paper is to mainly study the influencing factors of salt spray aerosol device to produce different particles diameter. And the investigation and study mainly include two aspects: numerical simulation and experimental study.
文摘Contaminated or infected patients present a risk of cross-contamination for emergency responders, attending medical personnel and medical facilities as they enter a treatment facility. The controlled conditions of an aerosol test chamber are required to examine factors of contamination, decontamination, and cross-contamination. This study presents the design, construction, and a method for characterizing an aerosol test chamber for a full-sized manikin on a standard North Atlantic Treaty Organization litter. The methodology combined air velocity measurements, aerosol particle counts and size distributions, and computational fluid dynamics modeling to describe the chamber’s performance in three dimensions. This detailed characterization facilitates future experimental design by predicting chamber performance for a variety of patient-focused research.
文摘The tapered element oscillating microbalance with filter dynamics measurement system （TEOM-FDMS） is an instrument commonly employed by the French air quality monitoring network. This instrument is currently calibrated with calibration weights traceable to SI but having value and mass differences between each of them that are not representative of real atmospheric particle mass measurements. Moreover, these calibration weights do not allow detection of any technical problems associated with either the TEOM-FDMS sampling system upstream of the mass measurement or the intrinsic TEOM-FDMS filtration system. Therefore, a calibration method was developed using a portable reference aerosol generator （PRAG） that produces known and stable particle mass concentrations over time. Here, we present the characterization of the PRAG system in terms of a reference range of particle masses between 30 - 10 and 3456 ± 83 μg at three sampling times. Its coupling with the TEOM-FDMS and a global comparison between the defined reference range of particle masses and the measured masses obtained with each TEOM-FDMS implicated in this study are also presented.
