Tesis sobre el tema "Cloud microphysic"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 50 mejores tesis para su investigación sobre el tema "Cloud microphysic".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore tesis sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
BHOWMICK, TARAPRASAD. "A numerical investigation of a few problems in cloud microphysics". Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2868592.
Texto completoOvtchinnikov, Mikhail. "An investigation of ice production mechanisms using a 3-D cloud model with explicit microphysics /". Full-text version available from OU Domain via ProQuest Digital Dissertations, 1997.
Buscar texto completoDavid, Robert O. "Cloud Dynamics and Microphysics during CAMPS| A Comparison between Airborne and Mountaintop Cloud Microphysics". Thesis, University of Nevada, Reno, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1591334.
Texto completoOrographically-enhanced clouds are essential for global hydrological cycles. To better understand the structure and microphysics of orographically-enhanced clouds, an airborne study, the Colorado Airborne Mixed-Phase Cloud Study (CAMPS), and a ground-based field campaign, the Storm Peak Lab (SPL) Cloud Property Validation Experiment (StormVEx) were conducted in the Park Range of the Colorado Rockies. The CAMPS study utilized the University of Wyoming King Air (UWKA) to provide airborne cloud microphysical and meteorological data on 29 flights totaling 98 flight hours over the Park Range from December 15, 2010 to February 28, 2011. The UWKA was equipped with instruments that measured cloud droplet and ice crystal size distributions, liquid water content, and 3-dimensional wind speed and direction. The Wyoming Cloud Radar and LiDAR were also deployed during the campaign. These measurements are used to characterize cloud structure upwind and above the Park Range. StormVEx measured temperature and cloud droplet and ice crystal size distributions at SPL. The observations from SPL are used to determine mountain top cloud microphysical properties at elevations lower than the UWKA was able to sample in-situ. To assess terrain flow effects on cloud microphysics and structure, vertical profiles of temperature, humidity and wind were obtained from balloon borne soundings and verified with high resolution modeling. Comparisons showed that cloud microphysics aloft and at the surface were consistent with respect to snow growth processes and previous studies on terrain flow effects. Small ice crystal concentrations were routinely higher at the surface and a relationship between small ice crystal concentrations, large cloud droplet concentrations and temperature was observed, suggesting liquid-dependent ice nucleation near cloud base.
Williams, Robyn D. "Studies of Mixed-Phase Cloud Microphysics Using An In-Situ Unmanned Aerial Vehicle (UAV) Platform". Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7252.
Texto completoYoung, Gillian. "Understanding the nucleation of ice particles in polar clouds". Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/understanding-the-nucleation-of-ice-particles-in-polar-clouds(4f80f81b-ed06-480a-944b-6e3594ba8471).html.
Texto completoMineart, Gary M. "Multispectral satellite analysis of marine stratocumulus cloud microphysics". Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/23321.
Texto completoPetch, Jonathan. "Modelling the interaction of clouds and radiation using bulk microphysical schemes". Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308098.
Texto completoPringle, Kirsty Jane. "Aerosol - cloud interactions in a global model of aerosol microphysics". Thesis, University of Leeds, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431991.
Texto completoZuberi, Bilal 1976. "Microphysics of atmospheric aerosols : phase transitions and cloud formation mechanisms". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/17654.
Texto completoVita.
Includes bibliographical references (leaves 134-148).
Clouds play an extremely important role in our atmosphere, from controlling the local weather, air pollution and chemical balance in the atmosphere to affecting long-term climatic changes at local, regional and global scales. The mechanisms through which tropospheric clouds form are still not fully understood, leading to gross uncertainties in understanding the effect of atmospheric aerosols on the environment. Using laboratory measurements, microphysical properties of typical micro-meter size atmospheric aerosols are investigated in this study. Upper tropospheric ice clouds (cirrus) form when ice is nucleated either homogeneously or heterogeneously in aqueous aerosols. We have investigated the homogeneous and heterogeneous ice nucleation in aqueous particles. Our results for homogeneous nucleation in aqueous ammonium nitrate particles show that the current thermodynamic models do not correctly predict water activities in these particles under super-saturated conditions. High super-saturations are required for ice to nucleate homogeneously in aqueous ammonium nitrate particles. We have also investigated the role of crystallized salt cores, such as solid ammonium sulfate and letovicite, in the heterogeneous nucleation of ice in saturated aqueous ammonium sulfate particles. Our results show that the surface morphology and defects on microcrystals could result in the creation of active sites, leaving the crystallized salt cores as potent ice nuclei under certain conditions. We have also investigated the role of mineral dust and soot, major components of insoluble particulates in the atmosphere, as ice-nuclei. We have found mineral dust to be an effective ice nuclei but both fresh and aged soot do not promote ice nucleation in aqueous particles.
(cont.) Soot is the most ubiquitous aerosol in the atmosphere. The lifetime and microphysics of nano-porous soot has a large impact on earth's radiative budget, heterogeneous chemistry, urban and regional air pollution and human health. We have investigated the hydrophilic properties of both fresh and aged soot as a function of relative humidity. Our results show that fresh hydrophobic soot oxidized (aged) by OH/0₃/UV in the presence of water vapor or by exposure to concentrated HNO₃ becomes hydrophilic and exhibits a greater affinity for water. Due to this increased hydrophilicity, aged soot can be easily entrained inside existing liquid cloud droplets, and even activate as cloud condensation nuclei at high super-saturations, thus influencing its heterogeneous chemistry, radiative properties and atmospheric lifetime.
by Bilal Zuberi.
Ph.D.
Nichman, Leonid. "Optical measurements of the microphysical properties of aerosol and small cloud particles in the CLOUD project". Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/optical-measurements-of-the-microphysical-properties-of-aerosol-and-small-cloud-particles-in-the-cloud-project(ad792d0c-90d1-4704-b666-b75d284b40fe).html.
Texto completoPainemal, David. "Investigation of the Cloud Microphysics and Albedo Susceptibility of the Southeast Pacific Stratocumulus Cloud Deck". Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_dissertations/581.
Texto completoMorales, Betancourt Ricardo. "On the representation of sub-grid scale phenomena and its impact on clouds properties and climate". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50373.
Texto completoRémillard, Jasmine. "Cloud climatology and microphysics at Eureka using synergetic radar/lidar measurements". Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32392.
Texto completoMalgré leur importance dans le budget radiatif terrestre et les modèles atmosphériques, les nuages arctiques restent mal documentés et incompris. Le déploiement d'un radar millimétrique et d'un lidar à haute résolution spectrale à Eureka (80°N) en août 2005 offre un ensemble unique de données pour l'étude des nuages arctiques. Dans ce projet, des algorithmes synergétiques furent développés et appliqués à deux ans de données pour fournir une première climatologie des nuages et de leur microphysique à cet emplacement éloigné. Les résultats montrent un cycle annuel dans l'étendue des nuages. Ils sont surtout détectés dans les bas niveaux ou en une couche, particulièrement en hiver à cause de l'inversion thermique et du refroidissement radiatif du haut des nuages. Une analyse des vents a démontré que différentes directions sont reliées à différentes conditions nuageuses, alors qu'une forte canalisation des vents due à la topographie est présente dans les bas niveaux. De plus, la phase liquide fut détectée à l'année longue, avec une occurrence minimale en hiver causée par des températures plus froides. De la turbulence et un haut taux d'humidité semblent maintenir les particules liquides surfondues, particulièrement quand des cristaux de glace sont aussi présents. Les précipitations furent principalement identifiées durant l'été, surtout sous forme de virga, bien que la difficulté à distinguer la neige des nuages glacés a pu influencer les résultats. Finalement, la validation d'un satellite est possible grâce aux données d'Eureka, mais seulement sous des conditions homogènes et si les caractéristiques instrumentales
Raabe, Armin y Nicole Mölders. "Evaluation of cloudiness and snowfall simulated by a semi-spectral and a bulk-parameterization scheme of cloud microphysics for the passage of a Baltic heat cyclone". Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-213950.
Texto completoDie Unterschiede in den Konzepten zweier unterschiedlicher Parametrisierungen der Wolkenmikrophysik werden analysiert. Die Ergebnisse der Simulationen werden miteinander und mit den beobachteten Wolken- und Schneeverteilungen für eine Baltische Wärmezyklone verglichen. Die wesentlichen Unterschiede in den berechneten Verteilungen resultieren aus den verschiedenen Annahmen über Wolkeneis, die Eisklassen und die Größenverteilungen der Wolken- und Niederschlagspartikel. Beide Schemata sagen die Position und die wesentlichen Strukturen der Wolken- und Schneeverteilungen erfolgreich vorher. Dennoch überschätzt das eher konvektive Schema den Schneefall, während das andere ihn unterschätzt
Menon, Surabo, Jean-Louis Brenguier, Olivier Boucher, Paul Davison, Genio Anthony D. Del, Johann Feichter, Steven Ghan et al. "Evaluating aerosol/cloud/radiation process parameterizations with single-column models and Second Aerosol Characterization Experiment (ACE-2) cloudy column observations". Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-177303.
Texto completoSchmidt, Jörg. "Dual-field-of-view Raman lidar measurements of cloud microphysical properties". Doctoral thesis, Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-150408.
Texto completoDuane, William John. "Correcting middle infrared cloud reflectances for atmospheric effects". Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324809.
Texto completoMenon, Surabo, Jean-Louis Brenguier, Olivier Boucher, Paul Davison, Genio Anthony D. Del, Johann Feichter, Steven Ghan et al. "Evaluating aerosol/cloud/radiation process parameterizations with single-column models and Second Aerosol Characterization Experiment (ACE-2) cloudy column observations: Evaluating aerosol/cloud/radiation process parameterizations withsingle-column models and Second Aerosol Characterization Experiment (ACE-2) cloudy column observations". Wiley, 2003. https://ul.qucosa.de/id/qucosa%3A13455.
Texto completoTaylor, Jonathan P. "The remote retrieval of stratiform water cloud radiative and microphysical properties". Thesis, University of Reading, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357173.
Texto completoSheyko, Benjamin Andrew. "The development and application of sensitivity tools for investigating microphysical processes in atmospheric models". Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/54248.
Texto completoSmall, Jennifer D. "Observational studies of the microphysics and dynamics of warm cumulus clouds /". Diss., Digital Dissertations Database. Restricted to UC campuses, 2009. http://uclibs.org/PID/11984.
Texto completoKhairoutdinov, Marat. "Large-eddy simulation of stratocumulus-topped boundary layer with an explicit and a new bulk microphysics scheme /". Full-text version available from OU Domain via ProQuest Digital Dissertations, 1997.
Buscar texto completoRémillard, Jasmine. "Remote sensing of drizzle onset and cloud microphysical properties in marine stratocumulus". Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114395.
Texto completoLes nuages stratiformes de basse altitude restent un des facteurs imprévisibles dans les simulations du climat futur. Malgré leur rôle important dans le budget radiatif terrestre et le grand nombre de campagnes de terrain dédiées, plusieurs procédés à l'échelle nuageuse dans les stratocumulus marins demeurent mal représentés. Le déploiement dans les Açores d'un laboratoire mobile du programme « Atmospheric Radiation Measurement » pendant 19 mois a fourni l'ensemble de données d'observation au sol sur les nuages de couche limite marine le plus long et le plus complet à ce jour. Le premier objectif de ce projet fut la documentation de la fréquence d'apparition de différents systèmes de nuages et de précipitations dans les Açores en utilisant une combinaison de mesures passives et actives. L'analyse indique que, même si des nuages étaient souvent observés (près de 80 % du temps), en particulier dans la couche limite (~50 %), une couverture de stratocumulus seul persistait rarement plus d'une journée. En fait, de nombreux stratocumulus furent observés avec des cumulus en dessous. Ceci est lié à l'état découplé de la couche limite quasi-constant dans les Açores, contrairement à ce qui a été observé dans les stratocumulus du Pacifique. 35 cas de couverture d'un stratocumulus persistant principalement seul furent sélectionnés pour une analyse approfondie. Les résultats incluent des similarités avec d'autres études (par exemple, une couverture maximale durant la nuit, un besoin de nuages plus épais pour bruiner et l'importance du refroidissement radiatif au haut des nuages durant la nuit), ainsi que des différences (par exemple, les structures cohérentes représentent une plus petite fraction du flux ascendant de masse). Le deuxième objectif de ce projet fut de revisiter la détection des particules de bruine dans les stratocumulus en utilisant les observations radar. Tout d'abord, les distributions de tailles des gouttelettes de nuage et de bruine sont liées théoriquement aux mesures radar, en incluant les effects dynamiques. Ensuite, un modèle direct de spectres Doppler radar fut développé pour tester la sensibilité des mesures radar à des modifications de la contribution de la bruine. Finalement, un simple modèle 1-D à l'état d'équilibre fut exploité pour simuler la croissance de la bruine pendant sa descente dans un nuage, en utilisant le modèle direct pour relier de nouveau les données sortantes avec les observations radar. En utilisant cette combinaison de modèles, quelques caractéristiques de l'évolution de la bruine observées à l'intérieur de nuages stratocumulus continental et maritime furent examinées avec succès. Dans l'ensemble, il fut déterminé que l'asymétrie d'un spectre Doppler radar est un bon indicateur de la présence de jeunes gouttelettes de bruine, alors qu'un seuil de réflectivité ou de vitesse Doppler indique le changement de domination dans le spectre Doppler se produisant quand la bruine est bien développée. Le troisième et final objectif de ce projet fut de revisiter un autre défi de longue date : le recouvrement de propriétés microphysiques des nuages en utilisant une combinaison de mesures radar et radiométriques. Une nouvelle technique fut développée pour retrouver la distribution de tailles des particules nuageuses, en ajoutant un modèle microphysique de condensation dans des conditions de supersaturation en équilibre à une méthode populaire de recouvrement. Les résultats semblent raisonnables pour deux stratocumulus marins ne bruinant pas et la profondeur optique dérivée pour ces nuages se compare bien avec celle dérivée indépendamment avec un autre instrument. Les erreurs de recouvrement furent également estimées, démontrant la valeur ajoutée de la nouvelle technique.
Sehili, Aissa Mounir. "Coupling between complex multiphase chemistry and detailed microphysics in a size resolved cloud model". [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=979424763.
Texto completoNogherotto, Rita. "A numerical framework for multiple phase cloud microphysics in regional and global atmospheric models". Doctoral thesis, Università degli studi di Trieste, 2015. http://hdl.handle.net/10077/11140.
Texto completoThe Regional Climate Model RegCM4 (Giorgi et al., 2012) treats nonconvective clouds and precipitation following the Subgrid Explicit SUBEX param- eterization (Pal et al., 2000). This scheme includes a simple representation for the formation of raindrops and solves diagnostically the precipitation: rain forms when the cloud water content exceeds the autoconversion threshold, that is an increasing function of the temperature and assumes different values over the land and over the ocean to account for the difference in number of the cloud condensation nuclei over continental and oceanic regions. The SUBEX scheme does not account for the presence of clouds ice, and the fraction of ice is diagnosed as a function of temperature in the radiation scheme. Due to the increasing emphasis on cloud representations in the climate community and the forthcoming increasing resolution due to the inclusion, in the close future, of a non-hydrostatic compressible core, the treatment of the ice microphysics and a prognostic representation of the precipitation is required in RegCM4. This thesis presents the new parameterization for stratiform cloud microphysics and precipitation implemented in RegCM4. The approach of the new parameterization is based on an implicit numerical framework recently developed and implemented into the ECMWF operational forecasting model (Tiedtke, 1993). The new parameterization solves 5 prognostic equations for the water vapour, the liquid water, the rain, the ice and the snow mixing ratios. It allows a proper treatment of mixed-phase clouds and a more physically realistic representation of the precipitation as it is no more an instantaneous response to the microphysical processes occurring in clouds and is subjected to the horizontal advection. A first discussion of the results contains an evaluation of the vertical distributions of the main microphysical quantities, such as the liquid and ice water mixing ratios and the relative fractions. It also presents a series of sensitivity tests to understand how the moisture and radiation quantities respond to the variation of the microphysical parameters used in the scheme, such as the fall speeds of the falling categories, the autoconversion scheme and the evaporation coefficient. Cloud properties are afterwards evaluated through the implementation for RegCM4 of the new cloud evaluation COSP tool (Bodas-Salcedo et al., 2011), developed by the Cloud Feedback Model In- tercomparison Project (CFMIP), that facilitates the comparison of simulated clouds with observations from passive and active remote sensing by diagnosing from model outputs the quantities that would be observed from satellites if they were flying above an atmosphere similar to that predicted by the model. Different hypothesis are presented to explain the reasons for RegCM4 biases in representing different types of clouds over the tropical band and new prospectives for the future investigations designed to answer to the open questions are outlined.
XXVI Ciclo
1983
Dearden, Christopher. "Exploring the effects of microphysical complexity in numerical simulations of liquid and mixed-phase clouds". Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/exploring-the-effects-of-microphysical-complexity-in-numerical-simulations-of-liquid-and-mixedphase-clouds(abe4b249-a608-4a42-819c-962e2114d1ba).html.
Texto completoKoch, Dorothy, Yves Balkanski, Susanne E. Bauer, Richard C. Easter, Sylvaine Ferrachat, Steven J. Ghan, Corinna Hoose et al. "Soot microphysical effects on liquid clouds, a multi-model investigation". Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-184919.
Texto completoKoch, Dorothy, Yves Balkanski, Susanne E. Bauer, Richard C. Easter, Sylvaine Ferrachat, Steven J. Ghan, Corinna Hoose et al. "Soot microphysical effects on liquid clouds, a multi-model investigation". Copernicus Publication, 2011. https://ul.qucosa.de/id/qucosa%3A13767.
Texto completoRiley, Emily Marie. "A Global Survey of Clouds by CloudSat". Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_theses/198.
Texto completoSwann, Hugh. "The development and validation of a microphysics scheme for cloud resolving model simulations of deep convection". Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339515.
Texto completoVant-Hull, Brian. "Radiative and cloud microphysical effects of forest fire smoke over North America and Siberia". College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/7423.
Texto completoThesis research directed by: Atmospheric and Oceanic Sciences. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Kinney, Jacqueline Anne. "Retrieval of optical and microphysical properties of ice clouds using Atmospheric Radiation Measurement (ARM) data". Texas A&M University, 2005. http://hdl.handle.net/1969.1/2524.
Texto completoMcGouldrick, Kevin Bartholomew. "Microphysics and radiative-dynamical feedback in the near infrared brightness features in the Venus clouds". Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3273820.
Texto completoNachbar, Mario Alexander [Verfasser] y Thomas [Akademischer Betreuer] Leisner. "The microphysics of mesospheric cloud formation on Earth and Mars - Laboratory experiments / Mario Alexander Nachbar ; Betreuer: Thomas Leisner". Heidelberg : Universitätsbibliothek Heidelberg, 2018. http://d-nb.info/1177252538/34.
Texto completoNachbar, Mario [Verfasser] y Thomas [Akademischer Betreuer] Leisner. "The microphysics of mesospheric cloud formation on Earth and Mars - Laboratory experiments / Mario Alexander Nachbar ; Betreuer: Thomas Leisner". Heidelberg : Universitätsbibliothek Heidelberg, 2018. http://d-nb.info/1177252538/34.
Texto completoRaabe, Armin y Nicole Mölders. "Evaluation of cloudiness and snowfall simulated by a semi-spectral and a bulk-parameterization scheme of cloud microphysics for the passage of a Baltic heat cyclone". Wissenschaftliche Mitteilungen des Leipziger Instituts für Meteorologie ; 12 = Meteorologische Arbeiten aus Leipzig ; 4 (1999), S. 59-70, 1999. https://ul.qucosa.de/id/qucosa%3A15107.
Texto completoDie Unterschiede in den Konzepten zweier unterschiedlicher Parametrisierungen der Wolkenmikrophysik werden analysiert. Die Ergebnisse der Simulationen werden miteinander und mit den beobachteten Wolken- und Schneeverteilungen für eine Baltische Wärmezyklone verglichen. Die wesentlichen Unterschiede in den berechneten Verteilungen resultieren aus den verschiedenen Annahmen über Wolkeneis, die Eisklassen und die Größenverteilungen der Wolken- und Niederschlagspartikel. Beide Schemata sagen die Position und die wesentlichen Strukturen der Wolken- und Schneeverteilungen erfolgreich vorher. Dennoch überschätzt das eher konvektive Schema den Schneefall, während das andere ihn unterschätzt.
Lawless, Ryan Lee. "Sensitivity of the Mueller matrix to the optical and microphysical properties of cirrus clouds". Texas A&M University, 2005. http://hdl.handle.net/1969.1/4323.
Texto completoTaufour, Marie. "Validation et amélioration du schéma microphysique à deux moments LIMA à partir des observations de la campagne de mesures HyMeX". Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30325/document.
Texto completoThe triggering and growth of Convective systems is a complex process that extends from the synoptic scale, with the establishment of atmospheric circulations promoting convection, to the microscale, with the formation and growth processes of hydrometeors. This PhD focuses on these finest scales and investigates the contribution of complex cloud-microphysics to the occurrence and morphology of heavy precipitation events. The two-moment microphysical scheme LIMA evaluated in this study takes into account the evolution of a multimodal aerosol population and the prognostic treatment of its interaction with liquid and ice clouds and precipitation. First, the contribution of LIMA is evaluated in comparison to the ICE3 one-moment bulk microphysical scheme, which is less sophisticated and currently operational in the AROME model at Météo-France. In order to measure the performance of this new scheme, two case studies of the HyMeX campaign were simulated with the Meso-NH model and compared to a wide variety of available measurements. The assessment of cumulative precipitation shows a moderate impact of each of these microphysical schemes, but the difference is more pronounced in terms of convective systems composition and structure: the two moment microphysics develops a more realistic vertical structure and introduces more microphysical variability. The evaluation also identified biases in the scheme (such as an overestimation of rain drop diameters). Some improvements to the implementation of LIMA were proposed and evaluated on the same cases. Then, the scheme is used to perform a sensitivity test to the aerosol population on the same case studies. Tests on the concentration of idealized populations have shown that aerosols do not only affect primary production of cloud droplets and ice crystals but also precipitating hydrometeors, causing impacts on the development of simulated convective systems in terms of cloud composition and generated precipitation. Simulations based on a realistic aerosol population initialized from CAMS analyses also showed a moderate impact on cumulative precipitation, but a more significant improvement on the temporal evolution of the system (intensification, dissipation) and cloud composition, leading to a reduction of rain drop diameters in the studied cases
Targino, Admir Créso. "Regional studies of the optical, chemical and microphysical properties of atmospheric aerosols : Radiative impacts and cloud formation". Doctoral thesis, Stockholm University, Department of Meteorology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-740.
Texto completoAtmospheric particles are ubiquitous in the Earth’s atmosphere and have potential to influence atmospheric chemistry, visibility, global climate and human health, particularly downwind from major pollution sources. The main objective of this thesis was to investigate questions pertaining to the microphysical, chemical and optical properties of aerosol particles by using in situ data collected during four experiments carried out in different regions of the Northern Hemisphere.
The first two papers of this thesis reports on airborne measurements of the aerosol optical properties performed over the North Atlantic and the Los Angeles basin. Airmasses from Europe and North Africa are usually advected in over the North Atlantic, alternating with the background marine conditions. The results showed that the aerosols are not uniformly distributed in the area and variability in the aerosol fields occurs at sub-synoptic scales. It was also observed that the single scattering coefficient varied as the polluted plumes aged, suggesting a relationship between this quantity and transport time. The measurements performed around the Los Angeles basin showed that the area’s complex topography and local meteorological circulations exert a strong control on the distribution of the aerosol in the basin. Large spatio-temporal gradients in the aerosol optical properties were observed along a transect flown from the shore towards the mountains. Profiles flown over sites located on the mountains displayed a stratified configuration with elevated aerosol layers.
Airborne data of residual particles collected in orographic wave clouds over Scandinavia were analyzed using a single particle analysis technique. Mineral dust, organic aerosols and sea salt were the main group of particles identified. Residuals composed predominantly of mineral dust were found in glaciated clouds while organic residuals were found in liquid clouds. The results suggest that organic material may inhibit freezing and have considerable influence on supercooled clouds that form through heterogeneous pathways.
The partitioning of the aerosol particles between cloud droplets and interstitial air has been addressed in terms of their microphysical properties using data obtained at a mountain-top site in Sweden during a stratocumulus event. The results showed that the scavenging efficiency varied during the cloud event, and Aitken-mode particles were also efficiently scavenged in addition to accumulation-mode particles. It is hypothesized that alterations of the aerosol chemical composition occurred during the measurement period, modifying the hygroscopic nature of the particles and decreasing their activation diameter.
Xie, Yu. "The effect of ice crystal surface roughness on the retrieval of ice cloud microphysical and optical properties". Texas A&M University, 2003. http://hdl.handle.net/1969.1/5970.
Texto completoTargino, Admir Creso. "Regional studies of the optical, chemical and microphysical properties of atmospheric aerosols : radiative impacts and cloud formation /". Stockholm : Dept. of meteorology, Stockholm university, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-740.
Texto completoBrückner, Marlen. "Retrieval of optical and microphysical cloud properties using shipbased spectral solar radiation measurements over the Atlantic ocean". Universität Leipzig, 2015. https://ul.qucosa.de/id/qucosa%3A16653.
Texto completoIn dem vorliegenden Artikel werden abwärtsgerichtete spektrale Strahldichten analysiert, die mithilfe schiffsgebundener Beobachtungen über dem Atlantischen Ozean gemessen wurden. In Verbindung mit hochauflösenden Lidar und Mikrowellenradiometer Fernerkundungsverfahren werden optische und mikrophysikalische Wolkeneigenschaften aus spektralen Daten abgeleitet. Um Probleme bereits existierender Verfahren, die auf Transmissionen basieren, zu beseitigen, wird ein neuer Fernerkundungsalgorithmus vorgestellt, der nicht nur Zweideutigkeiten in der Bestimmung der Parameter umgeht, sondern auch den Einfluss von Messunsicherheiten verringert. Die Methode vergleicht gemessene spektrale Transmissionsverhältnisse bei sechs Wellenlängen mit modellierten Verhältnissen. Die neue Fernerkundungsmethode ist schnell und exakt, sodass sie für operative Zwecke geeignet ist. Sie wird für homogene und inhomogene Wasserwolken als auch für Cirren angewendet. Die Ergebnisse des neuen Ableitungsverfahrens werden mit Beobachtungen des Flüssigwasserpfades eines Mikrowellenradiometers verglichen. Daraus ergibt sich eine Überschätzung des Flüssigwasserpfades unter dicken Wolken, jedoch eine leichte Unterschätzung für dünne Wolken.
Loewe, Katharina [Verfasser]. "Arctic mixed-phase clouds : Macro- and microphysical insights with a numerical model / Katharina Loewe". Karlsruhe : KIT Scientific Publishing, 2017. http://www.ksp.kit.edu.
Texto completoThornton, Jenna Louise. "Ice particle size and roughness from novel techniques : in situ measurements and validation". Thesis, University of Hertfordshire, 2016. http://hdl.handle.net/2299/17644.
Texto completoShrestha, Rudra Kumar. "Towards an improved understanding of regional scale climate change in the Nepal Himalayas". Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/towards-an-improved-understanding-of-regional-scale-climate-change-in-the-nepal-himalayas(e2fe4192-a0ef-4d4e-be16-107b5c572d47).html.
Texto completoSchmidt, Jörg [Verfasser], Andreas [Akademischer Betreuer] Macke, Andreas [Gutachter] Macke y Herman [Gutachter] Russchenberg. "Dual-field-of-view Raman lidar measurements of cloud microphysical properties : Investigation of aerosol-cloud interactions / Jörg Schmidt ; Gutachter: Andreas Macke, Herman Russchenberg ; Betreuer: Andreas Macke". Leipzig : Universitätsbibliothek Leipzig, 2014. http://d-nb.info/123878867X/34.
Texto completoBrückner, Marlen. "Retrieval of Optical and Microphysical Cloud Properties Using Ship-based Spectral Solar Radiation Measurements over the Atlantic Ocean". Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-164322.
Texto completoAlbrecht, Rachel Ifanger. "Eletrificação dos sistemas precipitantes na região Amazônica: processos físicos e dinâmicos do desenvolvimento de tempestades". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/14/14133/tde-24102008-154430/.
Texto completoAmazonian convective systems have unique microphysical characteristics, varying from a maritime convective behavior (rainy season) to a continental behavior (wet-dry transition season). These characteristics modulate the electrification of these systems, however it is still not well understood which are the dominant processes that intensify the frequency of lightning from one season to another: aerosol effect, thermodynamics, large-scale variability, landscape or topography? To answer this question, the objective of this study was to identify and quantify the importance of each one of these effects on the electrification of convective systems over the Amazon. The methodology was based on the analysis of observational data from the field experiment DRYTOWET and a numerical model with charge transfer parameterizations and lightning discharges. The cloud-to-ground (CG) lightning discharges annual cycle presented that the electrical activity of the southwestern Amazonian precipitating systems increased during the transition between the dry and wet seasons (August to September), in association with the convective systems deepening. With the establishment of the wet season (November to March), the number of CGs decreased but the electrical activity continued. The mean annual percentage of cloud-to-ground lightning of positive polarity (+CGs) was 12%, increasing drastically to 25% in September during the transition between the dry and wet seasons. This percentage of +CGs raise happened simultaneously with the increase in the atmospheric pollution due to the pasture biomass burning, held by local farmers to prepare the soil for agriculture and livestock during the begging of first rains. On the other hand, the increase in %+CGs also occurred preferentially over pasture areas of Rondonia state. Through the analysis of radar precipitating systems that occurred during the field campaign DRYTOWET, it was noted that positive thunderstorms (storms that produced more than 50% of +CGs over 50% of their life time) were initiated in drier and higher lift condensation levels (cloud base height) environments than other storms (negative thunderstorms) during all the field experiment, especially in the end of the dry season (September-October). A higher cloud base height is associated with a shallower warm cloud depth (cloud base height to the 0oC isotherm) and consequently less entrainment, increasing the updrafts due to a more efficient processing of the convective available potential energy (CAPE). This increase in updrafts inside the clouds results in deeper and stronger thunderstorms. The higher cloud base heights is a characteristic from pasture regions, where the ratio between sensible and latent heats at surface is greater than forested areas, which increases the top of the planetary boundary layer. The differences in the aerosol total concentration and size distribution, due to the increase in the atmospheric pollution during the transition between the dry and wet seasons, were inconclusive in a possible aerosol effect in the strength of positive and negative thunderstorms, once the aerosol concentration diurnal cycle follows the cycle of the planetary boundary layer, that also regulates the warm cloud depth effect. Numerical simulation of an 1D cloud model, coupled with charge transfer between the hydrometeors, showed that the thermodynamic structure was the main responsible feature for cloud electrification, increasing the updraft velocities. The pollution effect was masked in simulations, which inhibit the warm precipitation and consequently strength the the mixed and cold regions of the cloud, was responsible for an increase in the number of smaller aggregated particles, like snow flakes and graupel, decreasing the electrification and lightning frequency.
Michael, Ryan A. "Fate of volatile chemicals during accretion on wet-growing hail". [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002796.
Texto completoMARTINS, Rafael Castelo Guedes. "Estudo da sensibilidade do modelo WRF às parametrizações de microfísica de nuvens e à assimilação de dados observados". Universidade Federal de Campina Grande, 2014. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1466.
Texto completoMade available in DSpace on 2018-08-15T19:02:39Z (GMT). No. of bitstreams: 1 RAFAEL CASTELO GUEDES MARTINS – TESE (PPGMet) 2014.pdf: 3362803 bytes, checksum: 5a99c28e73f6a95fef76f82f96d2edc4 (MD5) Previous issue date: 2014-12-12
Um dos principais desafios atuais da modelagem numérica da atmosfera trata da previsão quantitativa da precipitação e do posicionamento das nuvens de chuva. Este trabalho tem com o principal objetivo avaliar o desempenho das arametrizações de microfísicas na modelagem regional com ênfase no papel da informação de grande escala e sua influência sobre as simulações, e no uso de dados observados de radiossondagens como forma de acrescentar informação à modelagem . Inicialmente, duas reanálises (NCEP2 e ERAI) foram estatisticamente comparadas com dados de PCDs do Estado do Ceará. Verificou - se qu e a ERAI apresentou maior semelhança com as observações, principalmente para as variáveis diretamente ligadas à convecção. Em seguida, a ERAI foi utilizada como forçamento de grande escala em simulações com o modelo WRF. Observou- se que o uso de microfísica detalhada não melhora necessariamente a previsão do modelo, caso não sejam utilizados dados observados no local de estudo. Por último, duas simulações de alta resolução foram realizadas. Uma forçada pela reanálise sem modificação e outra forçada pela reanálise modificada utilizando o método de análise objetiva do WRF, para incluir as séries temporais de radiossondagens coletadas durante campanha experimental do Projeto CHUVA, em Fortaleza- CE. As duas simulações foram comparadas com dados observados pelo radiômetro para o mesmo local e período das radiossondagens . Observou - se que a inclusão das observações de sondagens na modelagem possibilita melhor modelagem de um sistema convectivo ocorrido em abril de 2011, principalmente para as variáveis ligadas à convecção. Este trabalho aponta, utilizando análises comparativas e estatísticas, que a utilização de uma maior densidade de dados observacionais válidos no modelo pode melhorar de forma muito mais eficiente o resultado da modelagem, do que mesmo a utilização do downscaling dinâmico do dado de grande escala ou a utilização de esquemas de microfísica detalhada, que, em algumas situações, pode inclusive inserir mais erros nos sistema s modelados.
The quantitative prediction of precipitation and the positioning of the rain clouds is one of the main challenges of numerical modeling of the atmosphere in present days. This work aims to evaluate the performance of the microphysical parameterizations in regional modeling, with emphasis on the role of large- scale information and its influence on the simulations, and the use of observational data from radiosondes as a way to add information to modeling. Initially, two reanalysis (NCEP2 and ERAI) were statistically compared with data from PCDs from the Ceará State. It was found that the ERAI showed similarity to the observations, especially for variables directly linked to convection. Then, the ERAI is used as large scale forcing in simulations with the WRF model. It was observed that the use of detailed microphysics does not necessarily improve the model performance, if in situ data were not used. Finally, two high resolution simulations were performed. The first f orced by reanalysis without modification and other forced by reanalysis using the modified method of objective analysis of the WRF, to include the time series of radiosonde observations collected during the experimental campaign of the CHUVA Project in Fortaleza- CE. The two simulations were compared with data observed by the radiometer to the same place and period of the radiosonde. It was observed that the inclusion of radiosonde observations in to the model leads to a better simulation of a convective system that occurred in April 2011, mostly for the variables related to convection. Using comparative statistical analysis, t his work points that the use of a higher density of valid observational data in the model can improve much more efficiently the model results than the use of a dynamic downscal ing of large- scale data or the use of schemes with detailed microphysics, which in some circumstances may even introduce more errors into the modeled system s.