Marine Cloud Brightening (MCB), should it ever need to be deployed, envisions the formation of 1017salt Cloud Condensation Nuclei (CCN) per second coming from each of several thousand vessels deployed worldwide. The c...Marine Cloud Brightening (MCB), should it ever need to be deployed, envisions the formation of 1017salt Cloud Condensation Nuclei (CCN) per second coming from each of several thousand vessels deployed worldwide. The creation of this many nuclei on such a vast scale, from micron- or submicron-sized seawater droplets, preferably mono-disperse, poses a considerable engineering challenge. Various existing or experimental spray methods were investigated for feasibility, resulting in the identification of a few with promising results. Electro-spraying from Taylor cone-jets, using either silicon micromachined long capillaries or short capillary polymer substrates attached to a porous substrate, appears to have the best potential for implementation of all the methods that have been investigated so far.展开更多
This research introduces a groundbreaking methodology aimed at mitigating storm and hurricane intensity through the application of a ground-based, manually operated Cloud Condensation Nuclei (CCN) Generator. To meet t...This research introduces a groundbreaking methodology aimed at mitigating storm and hurricane intensity through the application of a ground-based, manually operated Cloud Condensation Nuclei (CCN) Generator. To meet the demand for more comprehensive context and rationale, this study explores the escalating challenges presented by the growing intensity of hurricanes, exemplified by Hurricane IAN (2022). The controlled release of environmentally friendly aerosols into the atmosphere, achieved by combusting selected wood pieces and organic edible materials, is a pivotal response to the escalating threat of extreme weather events. By generating CCN, the novel approach seeks to augment positive lightning in the eyewall, providing a potential solution to the intensification of hurricanes. Results illustrate the successful implementation of the methodology, with released aerosols effectively reaching the clouds for seeding, thus contributing to the modification of convection in the outer wall of Hurricane IAN and consequent intensity reduction. Rigorous experiments, incorporating considerations of various parameters such as wind patterns and the experimental location in Sarasota City, emphasize the scientific rigor applied to weakening Hurricane IAN. This comprehensive approach not only holds promise in mitigating hurricane intensity but also sheds light on the potential impact of cloud seeding in reducing the severity of future hurricanes, addressing a critical need for sustainable solutions to climate-related challenges.展开更多
A continuous flow streamwise thermal gradientcloud condensation nuclei(CCN)counter with anaerosol focusing and a laser-charge-coupled device(CCD)camera detector system was developed here.The countingperformance of the...A continuous flow streamwise thermal gradientcloud condensation nuclei(CCN)counter with anaerosol focusing and a laser-charge-coupled device(CCD)camera detector system was developed here.The countingperformance of the laser-CCD camera detector system wasevaluated by comparing its measured number concentrationswith those measured with a condensation particlecounter(CPC)using polystyrene latex(PSL)and NaClparticles of varying sizes.The CCD camera parameters(e.g.brightness,gain,gamma,and exposure time)wereoptimized to detect moving particles in the sensing volumeand to provide the best image to count them.The CCNcounter worked well in the particle number concentrationrange of 0.6-8000#·cm^(-3)and the minimum detectablesize was found to be 0.5μm.The supersaturation in theCCN counter with varying temperature difference wasdetermined by using size-selected sodium chloride particlesbased on Köhler equation.The developed CCNcounter was applied to investigate CCN activity ofatmospheric ultrafine particles at 0.5%supersaturation.Data showed that CCN activity increased with increasingparticle size and that the higher CCN activation forultrafine particles occurred in the afternoon,suggesting thesignificant existence of hygroscopic or soluble species inphotochemically-produced ultrafine particles.展开更多
2014年4~5月期间,搭乘“东方红二号”科考船(R/V)对黄海和渤海大气中凝结核数浓度(Concentrations of atmospheric particles,Ncn)、云凝结核数浓度(Concentrations of cloudcondensation nuclei,Nccn)、污染气体(SO2,O3)浓度以及大气...2014年4~5月期间,搭乘“东方红二号”科考船(R/V)对黄海和渤海大气中凝结核数浓度(Concentrations of atmospheric particles,Ncn)、云凝结核数浓度(Concentrations of cloudcondensation nuclei,Nccn)、污染气体(SO2,O3)浓度以及大气颗粒物粒径分布进行了走航观测。观测结果显示,在整个航次期间,Ncn的变化范围为(2.7~57.6)×10^3 cm^-3,平均值为(12.6±7.0)×10^3 cm^-3。Ncn和Nccn在渤海最高,北黄海次之,南黄海最低,其中渤海的Ncn比北黄海和南黄海的Ncn分别高出41%和85%,在0.2%过饱和度(Supersaturation,SS)0.4%SS和1.0%SS下,渤海的Nccn比北黄海和南黄海的Nccn分别高出8%和17%、23%和30%以及38%和50%。南黄海在0.2%SS、0.4%SS和1.0%SS对应的活化效率(Activation ratio,AR)分别为0.25±0.08、0.52±0.14和0.56±0.14;北黄海和渤海在0.2%SS、0.4%SS和1.0%SS下对应的AR分别为0.24±0.10和0.17±0.07,0.47±0.15和0.38±0.16以及0.53±0.17和0.50±0.19。AR值在渤海最小,北黄海次之,南黄海最大,这可能是因为在不同海域气溶胶颗粒物粒径分布的差异,导致了气溶胶颗粒物活化为CCN效率的不同。此外,观测到一次新粒子生成(New particle formation,NPF)事件,当新粒子的中值粒径增长到40 nm左右时,Nccn在1.0%SS下升高127%,0.4%SS下升高36%,0.2%SS下没有变化。最后,探究了Ncn与SO2在近海大气中的关系,即:Ncn=1.7×10^3 SO2+3.4×10^3。展开更多
文摘Marine Cloud Brightening (MCB), should it ever need to be deployed, envisions the formation of 1017salt Cloud Condensation Nuclei (CCN) per second coming from each of several thousand vessels deployed worldwide. The creation of this many nuclei on such a vast scale, from micron- or submicron-sized seawater droplets, preferably mono-disperse, poses a considerable engineering challenge. Various existing or experimental spray methods were investigated for feasibility, resulting in the identification of a few with promising results. Electro-spraying from Taylor cone-jets, using either silicon micromachined long capillaries or short capillary polymer substrates attached to a porous substrate, appears to have the best potential for implementation of all the methods that have been investigated so far.
文摘This research introduces a groundbreaking methodology aimed at mitigating storm and hurricane intensity through the application of a ground-based, manually operated Cloud Condensation Nuclei (CCN) Generator. To meet the demand for more comprehensive context and rationale, this study explores the escalating challenges presented by the growing intensity of hurricanes, exemplified by Hurricane IAN (2022). The controlled release of environmentally friendly aerosols into the atmosphere, achieved by combusting selected wood pieces and organic edible materials, is a pivotal response to the escalating threat of extreme weather events. By generating CCN, the novel approach seeks to augment positive lightning in the eyewall, providing a potential solution to the intensification of hurricanes. Results illustrate the successful implementation of the methodology, with released aerosols effectively reaching the clouds for seeding, thus contributing to the modification of convection in the outer wall of Hurricane IAN and consequent intensity reduction. Rigorous experiments, incorporating considerations of various parameters such as wind patterns and the experimental location in Sarasota City, emphasize the scientific rigor applied to weakening Hurricane IAN. This comprehensive approach not only holds promise in mitigating hurricane intensity but also sheds light on the potential impact of cloud seeding in reducing the severity of future hurricanes, addressing a critical need for sustainable solutions to climate-related challenges.
基金The research described in this paper was supported by the National Research Foundation of Korea(NRF)Grant Funded by the Korean Government(MEST)(NRF-2011-0015548 and NRF-2010-013-D00034)。
文摘A continuous flow streamwise thermal gradientcloud condensation nuclei(CCN)counter with anaerosol focusing and a laser-charge-coupled device(CCD)camera detector system was developed here.The countingperformance of the laser-CCD camera detector system wasevaluated by comparing its measured number concentrationswith those measured with a condensation particlecounter(CPC)using polystyrene latex(PSL)and NaClparticles of varying sizes.The CCD camera parameters(e.g.brightness,gain,gamma,and exposure time)wereoptimized to detect moving particles in the sensing volumeand to provide the best image to count them.The CCNcounter worked well in the particle number concentrationrange of 0.6-8000#·cm^(-3)and the minimum detectablesize was found to be 0.5μm.The supersaturation in theCCN counter with varying temperature difference wasdetermined by using size-selected sodium chloride particlesbased on Köhler equation.The developed CCNcounter was applied to investigate CCN activity ofatmospheric ultrafine particles at 0.5%supersaturation.Data showed that CCN activity increased with increasingparticle size and that the higher CCN activation forultrafine particles occurred in the afternoon,suggesting thesignificant existence of hygroscopic or soluble species inphotochemically-produced ultrafine particles.
