Journal ArticleDOI
Flood or drought: How do aerosols affect precipitation?
Daniel Rosenfeld,Ulrike Lohmann,Graciela B. Raga,Colin D. O'Dowd,Markku Kulmala,Sandro Fuzzi,Anni Reissell,Meinrat O. Andreae +7 more
TLDR
A conceptual model is proposed that explains this apparent dichotomy of pristine tropical clouds with low CCN concentrations rain out too quickly to mature into long-lived clouds and heavily polluted clouds evaporate much of their water before precipitation can occur.Abstract:
Aerosols serve as cloud condensation nuclei (CCN) and thus have a substantial effect on cloud properties and the initiation of precipitation. Large concentrations of human-made aerosols have been reported to both decrease and increase rainfall as a result of their radiative and CCN activities. At one extreme, pristine tropical clouds with low CCN concentrations rain out too quickly to mature into long-lived clouds. On the other hand, heavily polluted clouds evaporate much of their water before precipitation can occur, if they can form at all given the reduced surface heating resulting from the aerosol haze layer. We propose a conceptual model that explains this apparent dichotomy.read more
Citations
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疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A
TL;DR: PfPMP1）与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作�ly.
Book ChapterDOI
Clouds and Aerosols
Olivier Boucher,David A. Randall,Paulo Artaxo,Christopher S. Bretherton,Graham Feingold,Piers M. Forster,Veli-Matti Kerminen,Yutaka Kondo,Hong Liao,Ulrike Lohmann,Philip J. Rasch,Sathianeson Satheesh,Steven C. Sherwood,Bjorn Stevens,Xiaoye Zhang +14 more
Journal ArticleDOI
Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation
Jasper Kirkby,Joachim Curtius,Joao Almeida,Joao Almeida,Eimear M. Dunne,Jonathan Duplissy,Jonathan Duplissy,Jonathan Duplissy,Sebastian Ehrhart,Alessandro Franchin,Stephanie Gagne,Stephanie Gagne,Luisa Ickes,Andreas Kürten,Agnieszka Kupc,A. Metzger,Francesco Riccobono,Linda Rondo,Siegfried Schobesberger,Georgios Tsagkogeorgas,Daniela Wimmer,António Amorim,F. Bianchi,F. Bianchi,Martin Breitenlechner,A. David,Josef Dommen,Andrew J. Downard,Mikael Ehn,Richard C. Flagan,S. Haider,Armin Hansel,Daniel Hauser,Werner Jud,Heikki Junninen,Fabian Kreissl,Alexander N. Kvashin,Ari Laaksonen,Katrianne Lehtipalo,Jorge Lima,Edward R. Lovejoy,Vladimir Makhmutov,Serge Mathot,Jyri Mikkilä,Pierre Minginette,S. Mogo,Tuomo Nieminen,Antti Onnela,Paulo J. Pereira,Tuukka Petäjä,R. Schnitzhofer,John H. Seinfeld,Mikko Sipilä,Mikko Sipilä,Yuri Stozhkov,Frank Stratmann,António Tomé,Joonas Vanhanen,Yrjö Viisanen,Aron Vrtala,Paul E. Wagner,Hansueli Walther,Ernest Weingartner,Heike Wex,Paul M. Winkler,Kenneth S. Carslaw,Douglas R. Worsnop,Urs Baltensperger,Markku Kulmala +68 more
TL;DR: First results from the CLOUD experiment at CERN are presented, finding that atmospherically relevant ammonia mixing ratios of 100 parts per trillion by volume, or less, increase the nucleation rate of sulphuric acid particles more than 100–1,000-fold and ion-induced binary nucleation of H2SO4–H2O can occur in the mid-troposphere but is negligible in the boundary layer.
Journal ArticleDOI
Untangling aerosol effects on clouds and precipitation in a buffered system
Bjorn Stevens,Graham Feingold +1 more
TL;DR: It is proposed that the difficulty in untangling relationships among the aerosol, clouds and precipitation reflects the inadequacy of existing tools and methodologies and a failure to account for processes that buffer cloud and precipitation responses to aerosol perturbations.
Journal ArticleDOI
Ice nucleation by particles immersed in supercooled cloud droplets
TL;DR: Aerosol species which have been identified in the past as potentially important ice nuclei are introduced and their ice-nucleating ability when immersed in a supercooled droplet is addressed and the importance of ice nucleation by different aerosol types is estimated.
References
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Journal ArticleDOI
The Role of Sea Spray in Cleansing Air Pollution over Ocean via Cloud Processes
TL;DR: Observations show that precipitation from similar polluted clouds over oceans is much less affected, because large sea salt nuclei override the precipitation suppression effect of the large number of small pollution nuclei.
Journal ArticleDOI
The effects of aerosols on precipitation and dimensions of subtropical clouds: a sensitivity study using a numerical cloud model
Amit Teller,Zev Levin +1 more
TL;DR: In this paper, the effects of increased concentrations of Cloud Condensation Nuclei (CCN), giant CCN (GCCN) and ice nuclei (IN) on the development of precipitation and cloud structure in mixed-phase sub-tropical convective clouds were investigated using the Tel-Aviv University 2D cloud model.
Journal ArticleDOI
A modeling study of the response of tropical deep convection to the increase of cloud condensation nuclei concentration: 1. Dynamics and microphysics
TL;DR: In this article, the responses of cloud physical processes of a developing tropical deep convection to the increase of CCN concentration have been studied using a three-dimensional cloud-resolving model.
Journal Article
A modeling study on the climate impacts of black carbon aerosols
TL;DR: In this article, a three-dimensional interactive aerosol-climate model has been developed and used to study the climatic impact of black carbon (BC) aerosols when compared with the model's natural variability, significant globalscale changes caused by BC aerosols occurred in surface latent and sensible heat flux, surface net long-wave radiative flux, planetary boundary layer height, convective precipitation, and low-cloud coverage (positive), all closely related to the hydrological cycle.
Journal ArticleDOI
An experimental investigation of the effect of air pollution on the initiation of rain
Ross Gunn,B. B. Phillips +1 more
TL;DR: In this article, the authors show that the size of newly formed cloud droplets depends critically upon the cleanliness of the processed air and that droplets formed in ordinary air are usually too small to precipitate, but large droplets created overhead by condensation in sufficiently clean air may fall through the polluted cloud and initiate rain through association processes.