Relevant bibliographies by topics / Lower boundary of clouds

Academic literature on the topic 'Lower boundary of clouds'

Author: Grafiati
Published: 30 May 2022
Last updated: 31 May 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Contents

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Lower boundary of clouds.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Lower boundary of clouds"

1

Chen, G., H. Xue, G. Feingold, and X. Zhou. "Vertical transport of pollutants by shallow cumuli from large eddy simulations." Atmospheric Chemistry and Physics Discussions 12, no. 5 (May 3, 2012): 11391–413. http://dx.doi.org/10.5194/acpd-12-11391-2012.

Full text
Abstract:
Abstract. This study investigates the vertical transport of a passive tracer in a shallow cumulus boundary layer using large eddy simulations. The tracer source is at the surface in one case, and in the inversion layer in the other case. Results show that shallow cumulus clouds can significantly enhance vertical transport of the tracer in both cases. In the case with surface-borne pollutants, cloudy regions are responsible for the upward transport, due to the intense updrafts in cumulus clouds. In the case where pollutants are aloft, cloud-free regions are responsible for the downward transport, but the downward transport mainly occurs in thin regions around cloud edges. This is consistent with previous aircraft measurements of downdrafts around cumulus clouds and indicates that the downward transport is also cloud-induced. We also preformed cloud-free sensitivity runs for the two cases. Results show that this dry convection can neither transport the surface-borne pollutants into the inversion layer, nor transport pollutants from the inversion layer downward to the lower boundary layer. Cumulus convection is therefore more effective than dry convection at venting pollutants upward from the surface, and fumigating pollutants in the inversion layer downward into the lower boundary layer.
APA, Harvard, Vancouver, ISO, and other styles
2

Wang, Yuqing, Shang-Ping Xie, Bin Wang, and Haiming Xu. "Large-Scale Atmospheric Forcing by Southeast Pacific Boundary Layer Clouds: A Regional Model Study*." Journal of Climate 18, no. 7 (April 1, 2005): 934–51. http://dx.doi.org/10.1175/jcli3302.1.

Full text
Abstract:
Abstract A regional model is used to study the radiative effect of boundary layer clouds over the southeast Pacific on large-scale atmosphere circulation during August–October 1999. With the standard settings, the model simulates reasonably well the large-scale circulation over the eastern Pacific, precipitation in the intertropical convergence zone (ITCZ) north of the equator, and marine boundary layer stratocumulus clouds to the south. In a sensitivity experiment with the radiative effect of liquid clouds south of the equator over the eastern Pacific artificially removed, boundary layer clouds south of the equator almost disappear and precipitation in the ITCZ is reduced by 15%–20%, indicating that the stratocumulus clouds over the southeast Pacific have both local and cross-equatorial effects. Examination of the differences between the control and sensitivity experiments indicates that clouds exert a net diabatic cooling in the inversion layer. In response to this cloud-induced cooling, an in situ anomalous high pressure system develops in the boundary layer and an anomalous shallow meridional circulation develops in the lower troposphere over the equatorial eastern Pacific. At the lower branch of this shallow circulation, anomalous boundary layer southerlies blow from the boundary layer high toward the northern ITCZ where the air ascends. An anomalous returning flow (northerly) just above the cloud layer closes the shallow circulation. This low-level anomalous shallow circulation enhances the subsidence over the southeast Pacific above the cloud layer, helping to maintain boundary layer clouds and temperature inversion there. Meanwhile, the strengthened cross-equatorial flow near the surface enhances moisture convergence and convection in the ITCZ north of the equator. This in turn strengthens the local, deep Hadley circulation and hence the large-scale subsidence and boundary layer clouds over the southeast Pacific. This positive feedback therefore enhances the interhemispheric climate asymmetry over the tropical eastern Pacific.
APA, Harvard, Vancouver, ISO, and other styles
3

Chen, G., H. Xue, G. Feingold, and X. Zhou. "Vertical transport of pollutants by shallow cumuli from large eddy simulations." Atmospheric Chemistry and Physics 12, no. 23 (December 3, 2012): 11319–27. http://dx.doi.org/10.5194/acp-12-11319-2012.

Full text
Abstract:
Abstract. This study investigates the vertical transport of a passive tracer in a shallow cumulus boundary layer using large eddy simulations. The tracer source is at the surface in one case, and in the inversion layer in the other case. Results show that shallow cumulus clouds can significantly enhance vertical transport of the tracer in both cases. In the case with surface-borne pollutants, cloudy regions are responsible for the upward transport, due to the intense updrafts in cumulus clouds. In the case where pollutants are aloft, cloud-free regions are responsible for the downward transport, but the downward transport mainly occurs in thin regions around cloud edges. This is consistent with previous aircraft measurements of downdrafts around cumulus clouds and indicates that the downward transport is also cloud-induced. Cumulus convection is therefore able to both vent pollutants upward from the surface and fumigate pollutants in the inversion layer downward into the lower boundary layer.
APA, Harvard, Vancouver, ISO, and other styles
4

Lin, Wuyin, Minghua Zhang, and Norman G. Loeb. "Seasonal Variation of the Physical Properties of Marine Boundary Layer Clouds off the California Coast." Journal of Climate 22, no. 10 (May 15, 2009): 2624–38. http://dx.doi.org/10.1175/2008jcli2478.1.

Full text
Abstract:
Abstract Marine boundary layer (MBL) clouds can significantly regulate the sensitivity of climate models, yet they are currently poorly simulated. This study aims to characterize the seasonal variations of physical properties of these clouds and their associated processes by using multisatellite data. Measurements from several independent satellite datasets [International Satellite Cloud Climatology Project (ISCCP), Clouds and the Earth’s Radiant Energy System–Moderate Resolution Imaging Spectroradiometer (CERES–MODIS), Geoscience Laser Altimeter System (GLAS), and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO)], in conjunction with balloon soundings from the mobile facility of the Atmospheric Radiation Measurement (ARM) program at Point Reyes and reanalysis products, are used to characterize the seasonal variations of MBL cloud-top and cloud-base heights, cloud thickness, the degree of decoupling between clouds and MBL, and inversion strength off the California coast. The main results from this study are as follows: (i) MBL clouds over the northeast subtropical Pacific in the summer are more prevalent and associated with a larger in-cloud water path than in winter. The cloud-top and cloud-base heights are lower in the summer than in the winter. (ii) Although the lower-tropospheric stability of the atmosphere is higher in the summer, the MBL inversion strength is only weakly stronger in the summer because of a negative feedback from the cloud-top altitude. Summertime MBL clouds are more homogeneous and are associated with lower surface latent heat flux than those in the winter. (iii) Seasonal variations of low-cloud properties from summer to winter resemble the downstream stratocumulus-to-cumulus transition of MBL clouds in terms of MBL depth, cloud-top and cloud-base heights, inversion strength, and spatial homogeneity. The “deepening–warming” mechanism of Bretherton and Wyant for the stratocumulus-to-trade-cumulus transition downstream of the cold eastern ocean can also explain the seasonal variation of low clouds from the summer to the winter, except that warming of the sea surface temperature needs to be taken as relative to the free-tropospheric air temperature, which occurs in the winter. The observed variation of low clouds from summer to winter is attributed to the much larger seasonal cooling of the free-tropospheric air temperature than that of the sea surface temperature.
APA, Harvard, Vancouver, ISO, and other styles
5

Eirund, Gesa K., Anna Possner, and Ulrike Lohmann. "The Impact of Warm and Moist Airmass Perturbations on Arctic Mixed-Phase Stratocumulus." Journal of Climate 33, no. 22 (November 15, 2020): 9615–28. http://dx.doi.org/10.1175/jcli-d-20-0163.1.

Full text
Abstract:
AbstractThe Arctic is known to be particularly sensitive to climate change. This Arctic amplification has partially been attributed to poleward atmospheric heat transport in the form of airmass intrusions. Locally, such airmass intrusions can introduce moisture and temperature perturbations. The effect of airmass perturbations on boundary layer and cloud changes and their impact on the surface radiative balance has received increased attention, especially over sea ice with regard to sea ice melt. Utilizing cloud-resolving model simulations, this study addresses the impact of airmass perturbations occurring at different altitudes on stratocumulus clouds for open-ocean conditions. It is shown that warm and moist airmass perturbations substantially affect the boundary layer and cloud properties, even for the relatively moist environmental conditions over the open ocean. The cloud response is driven by temperature inversion adjustments and strongly depends on the perturbation height. Boundary layer perturbations weaken and raise the inversion, which destabilizes the lower troposphere and involves a transition from stratocumulus to cumulus clouds. In contrast, perturbations occurring in the lower free troposphere lead to a lowering but strengthening of the temperature inversion, with no impact on cloud fraction. In simulations where free-tropospheric specific humidity is further increased, multilayer mixed-phase clouds form. Regarding energy balance changes, substantial surface longwave cooling arises out of the stratocumulus break-up simulated for boundary layer perturbations. Meanwhile, the net surface longwave warming increases resulting from thicker clouds for airmass perturbations occurring in the lower free troposphere.
APA, Harvard, Vancouver, ISO, and other styles
6

Ahlgrimm, Maike, David A. Randall, and Martin Köhler. "Evaluating Cloud Frequency of Occurrence and Cloud-Top Height Using Spaceborne Lidar Observations." Monthly Weather Review 137, no. 12 (December 1, 2009): 4225–37. http://dx.doi.org/10.1175/2009mwr2937.1.

Full text
Abstract:
Abstract A strategy for model evaluation using spaceborne lidar observations is presented. Observations from the Geoscience Laser Altimeter System are recast onto the model grid to assess the ability of two versions of the Integrated Forecasting System to model marine stratocumulus clouds. The two model versions differ primarily in their treatment of clear and cloudy boundary layers. For each grid column, a representative cloud fraction and cloud-top height are derived from the observations, as well as from the model. By applying the same threshold criteria for cloud fraction and cloud-top height independently to model and observations, samples containing marine stratocumulus clouds can be identified. The frequency of occurrence, cloud fraction, and cloud-top height distributions for all samples thus identified are compared. The evaluation shows improvements in the frequency of occurrence and cloud-top height of marine stratocumulus, though modeled cloud tops remain lower than observed. Additional runs reveal a sensitivity to the strength of the environmental mixing that occurs during the test parcel ascent of the boundary layer parameterization. With a more aggressive parcel, the modeled clouds agree even better with observations.
APA, Harvard, Vancouver, ISO, and other styles
7

Solomon, Amy, and Matthew D. Shupe. "A Case Study of Airmass Transformation and Cloud Formation at Summit, Greenland." Journal of the Atmospheric Sciences 76, no. 10 (September 19, 2019): 3095–113. http://dx.doi.org/10.1175/jas-d-19-0056.1.

Full text
Abstract:
Abstract This study investigates cloud formation and transitions in cloud types at Summit, Greenland, during 16–22 September 2010, when a warm, moist air mass was advected to Greenland from lower latitudes. During this period there was a sharp transition between high ice clouds and the formation of a lower stratocumulus deck at Summit. A regional mesoscale model is used to investigate the air masses that form these cloud systems. It is found that the high ice clouds form in originally warm, moist air masses that radiatively cool while being transported to Summit. A sensitivity study removing high ice clouds demonstrates that the primary impact of these clouds at Summit is to reduce cloud liquid water embedded within the ice cloud and water vapor in the boundary layer due to vapor deposition on snow. The mixed-phase stratocumulus clouds form at the base of cold, dry air masses advected from the northwest above 4 km. The net surface radiative fluxes during the stratocumulus period are at least 20 W m−2 larger than during the ice cloud period, indicating that, in seasons other than summer, cold, dry air masses advected to Summit above the boundary layer may radiatively warm the top of the Greenland Ice Sheet more effectively than warm, moist air masses advected from lower latitudes.
APA, Harvard, Vancouver, ISO, and other styles
8

Harrison, R. Giles, Keri A. Nicoll, Evgeny Mareev, Nikolay Slyunyaev, and Michael J. Rycroft. "Extensive layer clouds in the global electric circuit: their effects on vertical charge distribution and storage." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 476, no. 2238 (June 2020): 20190758. http://dx.doi.org/10.1098/rspa.2019.0758.

Full text
Abstract:
A fair-weather electric field has been observed near the Earth's surface for over two centuries. The field is sustained by charge generation in distant disturbed weather regions, through current flow in the global electric circuit. Conventionally, the fair-weather part of the global circuit has disregarded clouds, but extensive layer clouds, important to climate, are widespread globally. Such clouds are not electrically inert, becoming charged at their upper and lower horizontal boundaries from vertical current flow, in a new electrical regime—neither fair nor disturbed weather; hence it is described here as semi-fair weather . Calculations and measurements show the upper cloud boundary charge is usually positive, the cloud interior positive and the lower cloud boundary negative, with the upper charge density larger, but of the same magnitude (∼nC m −2 ) as cloud base. Globally, the total positive charge stored by layer clouds is approximately 10 5 C, which, combined with the positive charge in the atmospheric column above the cloud up to the ionosphere, balances the total negative surface charge of the fair-weather regions. Extensive layer clouds are, therefore, an intrinsic aspect of the global circuit, and the resulting natural charging of their cloud droplets is a fundamental atmospheric feature.
APA, Harvard, Vancouver, ISO, and other styles
9

Achtert, Peggy, Ewan J. O'Connor, Ian M. Brooks, Georgia Sotiropoulou, Matthew D. Shupe, Bernhard Pospichal, Barbara J. Brooks, and Michael Tjernström. "Properties of Arctic liquid and mixed-phase clouds from shipborne Cloudnet observations during ACSE 2014." Atmospheric Chemistry and Physics 20, no. 23 (December 4, 2020): 14983–5002. http://dx.doi.org/10.5194/acp-20-14983-2020.

Full text
Abstract:
Abstract. This study presents Cloudnet retrievals of Arctic clouds from measurements conducted during a 3-month research expedition along the Siberian shelf during summer and autumn 2014. During autumn, we find a strong reduction in the occurrence of liquid clouds and an increase for both mixed-phase and ice clouds at low levels compared to summer. About 80 % of all liquid clouds observed during the research cruise show a liquid water path below the infrared black body limit of approximately 50 g m−2. The majority of mixed-phase and ice clouds had an ice water path below 20 g m−2. Cloud properties are analysed with respect to cloud-top temperature and boundary layer structure. Changes in these parameters have little effect on the geometric thickness of liquid clouds while mixed-phase clouds during warm-air advection events are generally thinner than when such events were absent. Cloud-top temperatures are very similar for all mixed-phase clouds. However, more cases of lower cloud-top temperature were observed in the absence of warm-air advection. Profiles of liquid and ice water content are normalized with respect to cloud base and height. For liquid water clouds, the liquid water content profile reveals a strong increase with height with a maximum within the upper quarter of the clouds followed by a sharp decrease towards cloud top. Liquid water content is lowest for clouds observed below an inversion during warm-air advection events. Most mixed-phase clouds show a liquid water content profile with a very similar shape to that of liquid clouds but with lower maximum values during events with warm air above the planetary boundary layer. The normalized ice water content profiles in mixed-phase clouds look different from those of liquid water content. They show a wider range in maximum values with the lowest ice water content for clouds below an inversion and the highest values for clouds above or extending through an inversion. The ice water content profile generally peaks at a height below the peak in the liquid water content profile – usually in the centre of the cloud, sometimes closer to cloud base, likely due to particle sublimation as the crystals fall through the cloud.
APA, Harvard, Vancouver, ISO, and other styles
10

Kravitz, Ben, Hailong Wang, Philip J. Rasch, Hugh Morrison, and Amy B. Solomon. "Process-model simulations of cloud albedo enhancement by aerosols in the Arctic." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 372, no. 2031 (December 28, 2014): 20140052. http://dx.doi.org/10.1098/rsta.2014.0052.

Full text
Abstract:
A cloud-resolving model is used to simulate the effectiveness of Arctic marine cloud brightening via injection of cloud condensation nuclei (CCN), either through geoengineering or other increased sources of Arctic aerosols. An updated cloud microphysical scheme is employed, with prognostic CCN and cloud particle numbers in both liquid and mixed-phase marine low clouds. Injection of CCN into the marine boundary layer can delay the collapse of the boundary layer and increase low-cloud albedo. Albedo increases are stronger for pure liquid clouds than mixed-phase clouds. Liquid precipitation can be suppressed by CCN injection, whereas ice precipitation (snow) is affected less; thus, the effectiveness of brightening mixed-phase clouds is lower than for liquid-only clouds. CCN injection into a clean regime results in a greater albedo increase than injection into a polluted regime, consistent with current knowledge about aerosol–cloud interactions. Unlike previous studies investigating warm clouds, dynamical changes in circulation owing to precipitation changes are small. According to these results, which are dependent upon the representation of ice nucleation processes in the employed microphysical scheme, Arctic geoengineering is unlikely to be effective as the sole means of altering the global radiation budget but could have substantial local radiative effects.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Lower boundary of clouds"

1

Новосьол, Катерина Ігорівна. "Математичне та програмне забезпечення для формулювання авіаційної метеодовідки." Master's thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/40116.

Full text
Abstract:
Магістерська дисертація складається зі вступу, чотирьох розділів, висновку та двох додатків, містить 14 рисунків, 29 таблиць та 15 джерел. Повний обсяг магістерської дисертації складає 98 сторінок, з яких додатки – 8 сторінок. До магістерської дипломної роботи Новосьол Катерини Ігорівни на тему: «Математичне та програмне забезпечення для формулювання авіаційної метеодовідки». Актуальність теми. Мета дослідження. Метою магістерської дисертації є дослідження функціонування аеропортів за складних метеорологічних умов, розробка показників функціонування аеропортів при цих умовах, розробка методики їх аналітичного і статистичного моделювання та розробка прикладного програмного забезпечення для формування коду довідки, який можна використати для передачі у повідомленні закритого вигляду. Для досягнення поставленої мети необхідно вирішити комплекс наступних взаємопов’язаних завдань: - проаналізувати існуючі показники метеорологічних умов, котрі впливають на функціонування аеропортів за складних метеорологічних умов; - проаналізувати методи формування метеодовідок та їх залежність від погодних параметрів; - дослідити вплив метеорологічних умов (а саме кліматичних характеристик) на політ літака; - дослідити динамічні процеси розвитку кліматичних характеристик з урахуванням метеорологічних умов; - розробити методику аналітичного та статистичного моделювання показників; - спроектувати та розробити програмне забезпечення для формування довідки із застосуванням запропонованої методики. Об’єктом дослідження є прикладне програмне забезпечення для для формування коду довідки, який можна використати для передачі у повідомленні закритого вигляду. Предметом дослідження є засоби автоматизації формування кодів метеорологіної довідки з урахуванням впливу кліматичних характеристик на політ повітряних суден у складних метеорологічних умовах. Методами дослідженняє загальнонаукові принципи проведення досліджень. В дослідженні використано методи: - наукового аналізу та синтезу для виявлення проблемних аспектів систем моделювання; - методи теорії ймовірності; - метод статистичного моделювання. Наукова новизна. Вперше сформовано метеодовідку, яка відрізняється від існуючих новою методикою виведення горизонтальної дальності видимості, що дозволяє підвищити точність прогнозування польоту. Практичне значення отриманих результатів.Результатом роботи є прикладний програмний застосунок для оцінювання метеорологічних характеристик аеродрому та формулювання авіаційної метеодовідки. Зв'язок роботи з науковими програмами, планами, темами. Дисертаційна робота магістра виконувалась у Національному технічному університеті України "Київський політехнічний інститут ім. Ігоря Сікорського" згідно з планом науково-дослідницьких робіт кафедри а автоматизованих систем обробки інформації та управління. Публікації. Наукові положення дисертації були опублікованіна V всеукраїнській науково-практичній конференції молодих вчених та студентів «Інформаційні системи та технології управління»(ІСТУ-2020).
The master's dissertation consists of an introduction, four chapters, a conclusion and two appendices, contains 14 figures, 29 tables and 15 sources. The full volume of the master's dissertation is 98 pages, of which the appendices are 8 pages. To Kateryna Ihorivna Novosyol's master's thesis on the topic: " Mathematical and software application for aviation meteorological report formulation ". Actuality of theme. The aim of the study. The purpose of the master's dissertation is to study the operation of airports in difficult weather conditions, to develop indicators of airport operation under these conditions, to develop methods for their analytical and statistical modeling and to develop application software for reference code that can be used to transmit in closed message. To achieve this goal it is necessary to solve a set of the following interrelated tasks: - to analyze the existing indicators of meteorological conditions that affect the functioning of airports in difficult meteorological conditions; - to analyze the methods of forming meteorological reports and their dependence on weather parameters; - to investigate the influence of meteorological conditions (namely climatic characteristics) on the flight of the aircraft; - to study the dynamic processes of development of climatic characteristics taking into account meteorological conditions; - to develop a method of analytical and statistical modeling of indicators; - to design and develop the software for formation of the reference with application of the offered technique. The object of the study is application software for generating help code, which can be used for transmission in a closed message. The subject of the research is the means of automating the formation of meteorological reference codes taking into account the influence of climatic characteristics on the flight of aircraft in difficult meteorological conditions. Research methods are general scientific principles of research. The study used the following methods: - scientific analysis and synthesis to identify problematic aspects of modeling systems; - methods of probability theory; - method of statistical modeling. Scientific novelty. For the first time a meteorological report was formed, which differs from the existing ones by a new method of deriving the horizontal range of visibility, which allows to increase the accuracy of flight forecasting. The practical significance of the results. The result of the work is an applied software application for assessing the meteorological characteristics of the aerodrome and the formulation of aviation meteorological information. Connection of work with scientific programs, plans, themes. The dissertation of the master was performed at the National Technical University of Ukraine "Kyiv Polytechnic Institute named after Igor Sikorsky" according to the plan of research work of the department of automated information processing and control systems. Publications. The scientific provisions of the dissertation were published at the V All-Ukrainian scientific-practical conference of young scientists and students "Information systems and management technologies" (ISTU-2020).
APA, Harvard, Vancouver, ISO, and other styles
2

Aronsson, Oskar, and Julia Nyman. "Boundary Representation Modeling from Point Clouds." Thesis, KTH, Bro- och stålbyggnad, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278543.

Full text
Abstract:
Inspections of bridges are today performed ocularly by an inspector at arm’s lengths distance to evaluate damages and to assess its current condition. Ocular inspections often require specialized equipment to aid the inspector to reach all parts of the bridge. The current state of practice for bridge inspection is therefore considered to be time-consuming, costly, and a safety hazard for the inspector. The purpose of this thesis has been to develop a method for automated modeling of bridges from point cloud data. Point clouds that have been created through photogrammetry from a collection of images acquired with an Unmanned Aerial Vehicle (UAV). This thesis has been an attempt to contribute to the long-term goal of making bridge inspections more efficient by using UAV technology. Several methods for the identification of structural components in point clouds have been evaluated. Based on this, a method has been developed to identify planar surfaces using the model-fitting method Random Sample Consensus (RANSAC). The developed method consists of a set of algorithms written in the programming language Python. The method utilizes intersection points between planes as well as the k-Nearest-Neighbor (k-NN) concept to identify the vertices of the structural elements. The method has been tested both for simulated point cloud data as well as for real bridges, where the images were acquired with a UAV. The results from the simulated point clouds showed that the vertices were modeled with a mean deviation of 0.13− 0.34 mm compared to the true vertex coordinates. For a point cloud of a rectangular column, the algorithms identified all relevant surfaces and were able to reconstruct it with a deviation of less than 2 % for the width and length. The method was also tested on two point clouds of real bridges. The algorithms were able to identify many of the relevant surfaces, but the complexity of the geometries resulted in inadequately reconstructed models.
Besiktning av broar utförs i dagsläget okulärt av en inspektör som på en armlängds avstånd bedömer skadetillståndet. Okulär besiktning kräver därmed ofta speciell utrustning för att inspektören ska kunna nå samtliga delar av bron. Detta resulterar i att det nuvarande tillvägagångssättet för brobesiktning beaktas som tidkrävande, kostsamt samt riskfyllt för inspektören. Syftet med denna uppsats var att utveckla en metod för att modellera broar på ett automatiserat sätt utifrån punktmolnsdata. Punktmolnen skapades genom fotogrammetri, utifrån en samling bilder tagna med en drönare. Uppsatsen har varit en insats för att bidra till det långsiktiga målet att effektivisera brobesiktning genom drönarteknik. Flera metoder för att identifiera konstruktionselement i punktmoln har undersökts. Baserat på detta har en metod utvecklats som identifierar plana ytor med regressionsmetoden Random Sample Consensus (RANSAC). Den utvecklade metoden består av en samling algoritmer skrivna i programmeringsspråket Python. Metoden grundar sig i att beräkna skärningspunkter mellan plan samt använder konceptet k-Nearest-Neighbor (k-NN) för att identifiera konstruktionselementens hörnpunkter. Metoden har testats på både simulerade punktmolnsdata och på punktmoln av fysiska broar, där bildinsamling har skett med hjälp av en drönare. Resultatet från de simulerade punktmolnen visade att hörnpunkterna kunde identifieras med en medelavvikelse på 0,13 − 0,34 mm jämfört med de faktiska hörnpunkterna. För ett punktmoln av en rektangulär pelare lyckades algoritmerna identifiera alla relevanta ytor och skapa en rekonstruerad modell med en avvikelse på mindre än 2 % med avseende på dess bredd och längd. Metoden testades även på två punktmoln av riktiga broar. Algoritmerna lyckades identifiera många av de relevanta ytorna, men geometriernas komplexitet resulterade i bristfälligt rekonstruerade modeller.
APA, Harvard, Vancouver, ISO, and other styles
3

Barber, Claire. "Observations and modelling of tropical marine boundary layer clouds." Thesis, University of Reading, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.590117.

Full text
Abstract:
Marine boundary layer (MBL) cloud and fog are ubiquitous over the global oceans, overlying more than 30% of the ocean surface. Due primarily to their large spatial extent, relat ively speaking minor changes in cloud radiative properties have the potential to sub-stantially affect the global radiation budget, and so future climate. Changes to a particular cloud property are often a small residual effect due to many competing processes. Therefore, modelled cloud changes can be associated with large uncertainties, and :MEL clouds were identified in the most recent IPCC report as the largest contributor to the spread in modelled cloud feedbacks . This thesis exploits the existence of long-term (30yr+ ), consistent, global satellite records of cloud extent and properties to evaluate the representation of MBL clouds in the recent Hadley Centre HadGEM-2A global climate model. In general, the position and fraction of MBL clouds is much improved over previous versions of the model. The representation of cloud liquid water path (L\VP), however, still requires improvement, with the model consistently underestimating LWP by as much as 50% relative to microwave-derived observations. Large differences between the retrieval of L\VP from different satellite platforms may contribute to the poorly constrained model representation of L\VP. The final part of this thesis constructs a well-constrained observational climatology of LWP, using microwave and visible-spectrwn derived satellite retrievals, for the West African Stratocwnulus region. For overcast, single layer cloud, latent heat flux (LHF) is found to be the best indicator of observed cloud L\VP compared to other surface and atmospheric measurements of heat and moisture. The advantages of well characterised and accurate measurements from multiple observational platforms for the purposes of model evaluation are emphasised throughout this thesis. ii
APA, Harvard, Vancouver, ISO, and other styles
4

Ehrlich, André, Eike Bierwirth, and Manfred Wendisch. "Airborne remote sensing of Arctic boundary-layer mixed-phase clouds." Universität Leipzig, 2010. https://ul.qucosa.de/id/qucosa%3A16357.

Full text
Abstract:
This article gives an overview on the investigations on Artic boundary-layer mixed-phase clouds conducted within the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR) in spring 2007. In particular the horizontal and vertical disribution of ice crystals within the clouds was determined by three independent airborne instruments (lidar, in situ and solar radiation measurements). Spectral measurements of cloud top reflectivity have been utilized to retrieve information on the ice phase by analyzing the spectral pattern of the cloud top reflectance in the wavelength range dominated by liquid water and ice absorption (1400-1700 nm). A new algorithm to derive an ice index which distinguishes pure ice, liquid water, and mixed-phase clouds was developed. The horizontal distribution of the ice index, observed during ASTAR 2007, agrees with airborne lidar and in situ measurements showing patches of glaciated clouds at an air mass transition zone within the investigated mixed-phase cloud fields. Information on the vertical distribution of ice crystals in mixed-phase clouds was derived by comparing the measured cloud top reflectivity in the wavelength band 1400-1700 nm to radiative transfer simulations. To interpret the data, the vertical weighting of the measurements was calculated. In the investigated wavelength range the weightings differ according to the spectral absorption of ice and liquid water. From the observed spectral cloud reflectivity with low values in the ice absorption maximum (1400 nm) and higher values at the liquid water absorption maximum (1700 nm) it was concluded that ice crystals were present in the otherwise liquid dominated cloud top layer. Although in situ measurements (limited due to vertical resolution and detection limits) did confirm these findings only in certain limits, the retrieved vertical structure is in agreement with published ground based remote sensing measurements.
APA, Harvard, Vancouver, ISO, and other styles
5

Paunova, Irena T. "Explicit numerical study of aerosol-cloud interactions in boundary layer clouds." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100670.

Full text
Abstract:
Aerosol-cloud interactions, the mechanisms by which aerosols impact clouds and precipitation and clouds impact aerosols as they are released upon droplet evaporation, are investigated by means of explicit high-resolution (3 km) numerical simulations with the Mesoscale Compressible Community (MC2) model. This model, which is non-hydrostatic and compressible, was extended by including separate continuity equations for dry and activated multi-modal aerosol, and for chemical species. The sources and sinks include: particle activation, solute transfer between drops, generation of extra soluble material in clouds via oxidation of dissolved SO2, and particle regeneration. The cloud processes are represented by an advanced double-moment bulk microphysical parameterization.
Three summertime cases have been evaluated: a marine stratus and a cold frontal system over the Bay of Fundy near Nova Scotia, formed on 1 Sep 1995 and extensively sampled as a part of the Radiation, Aerosol, and Cloud Experiment (RACE); and a continental stratocumulus, formed over the southern coast of Lake Erie on 11 July 2001. The marine stratus and the frontal system have been examined for the effects of aerosol on cloud properties and thoroughly evaluated against the available observations. The frontal system and the continental stratocumulus have been evaluated for the effects of cloud processing on the aerosol spectrum.
The marine stratus simulations suggest a significant impact of the aerosol on cloud properties. A simulation with mechanistic activation and a uni-modal aerosol showed the best agreement with observations in regards to cloud-base and cloud-top height, droplet concentration, and liquid water content. A simulation with a simple activation parameterization failed to simulate essential bulk cloud properties: droplet concentration was significantly underpredicted and the vertical structure of the cloud was inconsistent with the observations. A simulation with a mechanistic parameterization and a bi-modal aerosol, including a coarse mode observed in particle spectra below cloud, showed high sensitivity of droplet concentration to the inclusion of the coarse mode. There was a significant reduction in droplet number relative to the simulation without the coarse mode. A similar change occurred in the precipitating system preceding the stratus formation, resulting in an enhancement of precipitation in the weaker (upstream) part of the system while the precipitation in the more vigorous (downstream) part of the system remained almost unaffected.
Aerosol processing via collision-coalescence and aqueous chemistry in the non-drizzling stratocumulus case suggests that impact of the two mechanisms is of similar magnitude and can be as large as a 3-5 % increase in particle mean radius. A more detailed analysis reveals that the impact of chemical processing is oxidant-limited; beyond times when the oxidant (H 2O2) is depleted (∼ 40 minutes), the extent of processing is determined by supply of fresh oxidant from large-scale advection (fresh gaseous emissions are not considered). Aerosol processing via drop collision-coalescence alone suggests, as expected, sensitivity to the strength of the collection process in clouds. Larger particle growth, up to 5-10 %, is observed in the case of the frontal clouds, which exhibit stronger drop collection compared to that in the stratocumulus case. The processed aerosol exerted a measurable impact on droplet concentrations and precipitation production in the frontal clouds. For the case modeled here, contrary to expectations, the processed spectrum (via physical processing) produced higher droplet concentration than the unprocessed spectrum. The reasons explaining this phenomenon and the resulting impact on precipitation production are discussed.
The current work illustrates the complexity of the coupled system at the cloud system scales, revealed earlier at much smaller large eddy scales. If future parameterizations of the regional effect of aerosols on clouds are to be developed, careful consideration is required of the many of feedbacks in the boundary layer.
APA, Harvard, Vancouver, ISO, and other styles
6

Wang, Zhen, Ramirez Marco Mora, Hossein Dadashazar, Alex B. MacDonald, Ewan Crosbie, Kelvin H. Bates, Matthew M. Coggon, et al. "Contrasting cloud composition between coupled and decoupled marine boundary layer clouds." AMER GEOPHYSICAL UNION, 2016. http://hdl.handle.net/10150/622150.

Full text
Abstract:
Marine stratocumulus clouds often become decoupled from the vertical layer immediately above the ocean surface. This study contrasts cloud chemical composition between coupled and decoupled marine stratocumulus clouds for dissolved nonwater substances. Cloud water and droplet residual particle composition were measured in clouds off the California coast during three airborne experiments in July-August of separate years (Eastern Pacific Emitted Aerosol Cloud Experiment 2011, Nucleation in California Experiment 2013, and Biological and Oceanic Atmospheric Study 2015). Decoupled clouds exhibited significantly lower air-equivalent mass concentrations in both cloud water and droplet residual particles, consistent with reduced cloud droplet number concentration and subcloud aerosol (D-p>100nm) number concentration, owing to detachment from surface sources. Nonrefractory submicrometer aerosol measurements show that coupled clouds exhibit higher sulfate mass fractions in droplet residual particles, owing to more abundant precursor emissions from the ocean and ships. Consequently, decoupled clouds exhibited higher mass fractions of organics, nitrate, and ammonium in droplet residual particles, owing to effects of long-range transport from more distant sources. Sodium and chloride dominated in terms of air-equivalent concentration in cloud water for coupled clouds, and their mass fractions and concentrations exceeded those in decoupled clouds. Conversely, with the exception of sea-salt constituents (e.g., Cl, Na, Mg, and K), cloud water mass fractions of all species examined were higher in decoupled clouds relative to coupled clouds. Satellite and Navy Aerosol Analysis and Prediction System-based reanalysis data are compared with each other, and the airborne data to conclude that limitations in resolving boundary layer processes in a global model prevent it from accurately quantifying observed differences between coupled and decoupled cloud composition.
APA, Harvard, Vancouver, ISO, and other styles
7

Eleuterio, Daniel P. "Coastal stratocumulus topped boundary layers and the role of cloud-top entrainment." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FEleuterio%5PhD.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Schäfer, Michael, Eike Bierwirth, André Ehrlich, Evi Jäkel, and Manfred Wendisch. "Three-dimensional radiative effects in Arctic boundary layer clouds above ice edges." Universität Leipzig, 2015. https://ul.qucosa.de/id/qucosa%3A16651.

Full text
Abstract:
Based on airborne spectral imaging observations, three-dimensional (3-D) radiative effects between Arctic boundary layer clouds and highly variable Arctic surfaces have been identified and quantified. A method is presented to discriminate sea ice and open water in cloudy conditions based on airborne upward radiance measurements in the visible spectral range. This separation simultaneously reveals that the transition of radiance between open water and sea ice is not instantaneous in cloudy conditions but horizontally smoothed. In general, clouds reduce the nadir radiance above bright surfaces in the vicinity of open water, while the nadir radiance above open sea is enhanced compared to situations with clouds located above sea ice surfaces. With the help of the observations and 3-D radiative transfer simulations, this effect was quantified. This affected distance deltaL was found to depend on both cloud and sea ice properties. For a low level cloud at 0-200 m altitude, as observed during the Arctic field campaign Vertical Distribution of Ice in Arctic Clouds (VERDI) in 2012, an increase of the cloud optical thickness from tau = 1 to tau = 10 leads to a decrease of deltaL from 600 to 250 m. An increase in cloud base altitude or cloud geometrical thickness results in an increase of deltaL. Furthermore, the impact of these 3-D-radiative effects on a retrieval of cloud optical properties was investigated. The enhanced brightness of a dark pixel next to an ice edge results in uncertainties of up to 90 % in retrievals of tau and up to 30 % in retrievals of the effective radius reff. With the help of detlaL quantified here, an estimate of the distance to the ice edge is given where the retrieval uncertainties due to 3D-effects are negligible.
Mit Hilfe flugzeuggetragener abbildender spektraler Beobachtungen wurden 3-D Strahlungseffekte zwischen arktischen Grenzschichtwolken sowie der hochvariablen arktischen Bodenoberfläche identifiziert und quantifiziert. Eine Methode zur Differenzierung von Meereis und offener Wasserflächen, auf Grundlage flugzeuggetragener Messungen der aufwärtsgerichteten Strahldichte im sichtbaren Spektralbereich, während bewölkter Bedingungen wird vorgestellt. Diese Differenzierung zeigt gleichzeitig auf, dass die Strahldichtereduzierung beim Übergang vom Meereis zu den offenen Wasserflächen nicht unmittelbar erfolgt, sondern horizontal geglättet ist. Allgemein verringern Wolken in der Umgebung von Eiskanten die Nadir-Strahldichte über den hellen Eisflächen und erhöhen sie über dunklen Meeresoberflächen. Mit Hilfe von 3-D Strahlungstransferrechnungen wurde dieser Effekt quantifiziert. Die Reichweite dieses Effektes wird sowohl von den Wolken- als auch den Oberflächeneigenschaften beeinflusst. Für eine flache Wolke zwischen 0 und 200 m, so wie sie während der arktischen Feldkampagne Vertical Distribution of Ice in Arctic Clouds (VERDI), 2012 beobachtet werden konnte, führt eine Erhöhung der wolkenoptischen Dicke von tau = 1 zu tau = 10 zu einer Verringerung in deltaL von 600 zu 250 m. Zudem führt eine Erhöhung der Wolkenhöhe und ihrer geometrischen Dicke zu einer Zunahme von deltaL. Anschließend wurde der Einfluss dieser 3-D Strahlungseffekte auf die Ableitungsergebnisse von tau untersucht. Die Aufhellung eines dunkleren Pixels neben der Eiskante führt zu Unsicherheiten von bis zu 90 % bei der Ableitung von . Beim effektiven Radius zu bis zu 30 %. DeltaL ist ein Maß mit Hilfe dessen die Entfernung zur Eiskante bestimmt werden kann, ab welcher die Unsicherheiten bezüglich der 3-D Effekte vernachlässigt werden können.
APA, Harvard, Vancouver, ISO, and other styles
9

Kanngießer, Franz, André Ehrlich, and Manfred Wendisch. "Observations of glories above arctic boundary layer clouds to identify cloud phase." Universität Leipzig, 2017. https://ul.qucosa.de/id/qucosa%3A16743.

Full text
Abstract:
The glory is an optical phenomenon observed above liquid water clouds and consists of coloured rings around the anti-solar point. Since the glory is caused by scattering on spherical particles it can be used as a proxy to identify liquid water at the cloud top. Images taken with a CANON digital camera equipped with a fish-eye lens on board the research aircraft Polar 5 during the measurement campaign Radiation-Aerosol-Cloud Experiment in the Arctic Circle (RACEPAC) were analysed for glories. To identify glories an algorithm consisting of five criteria was developed by using simulations of the scattering angle dependent radiance and a test data set of measurements. The algorithm was tested and proved to be able to distinguish between images showing a glory and images not showing any glory.
Die Glorie ist eine optische Erscheinung, die über Flüssigwasserwolken beobachtet werden kann und aus farbigen Ringen um den Gegensonnenpunkt besteht. Da die Glorie durch Streuung an sphärischen Partikeln entsteht, kann sie zur Identifikation von Flüssigwasser am Wolkenoberrand genutzt werden. Bilder, die mit einer CANON Digitalkamera, die mit einem Fischaugenobjektiv ausgestattet war, von Bord des Forschungsflugzeugs Polar 5 während der Messkampagne RACEPAC aufgenommen worden, wurden auf das Auftreten von Glorien untersucht. Zur Identifikation wurde ein Algorithmus mit fünf Kriterien entwickelt, die mit Hilfe von Simulationen der streuwinkelabhängigen Radianz und einem Testdatensatz der Messungen erstellt wurden. Der Algorithmus wurde getestet und ist in der Lage zwischen Bildern mit und ohne Glorie zu unterscheiden.
APA, Harvard, Vancouver, ISO, and other styles
10

Teixeira, João Carlos Martins. "WRF sensitivity to lower boundary and urban canopy parametrizations." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10175.

Full text
Abstract:
Mestrado em Meteorologia e Oceanografia Física
Ao longo dos anos avanços, na tecnologia de satélite viabilizaram a aquisição de informações sobre a superfície da Terra, tais como elevação e uso do solo, com grande detalhe e resolução. Esta informação pode ser incluída em modelos numérico da atmosfera, atualizando e dando-lhes mais detalhes sobre as condições de fronteira inferior. Assim sendo, este trabalho visa estudar a sensibilidade do Weather Research and Forecasting model a três conjuntos de dados de topografia, e dois de uso do solo diferentes. Um caso de estudo em que a precipitação orográfica foi dominante sobre a Ilha da Madeira foi considerado mostrando que, em geral não existe um aumento significativo da performance do modelo ao usar topografia ou uso do solo de alta resolução. Contudo, existe uma melhor performance do modelo em simular a precipitação a barlavento e o fluxo a sotavento da ilha. Dada a natureza deste estudo, considerou-se também um teste à sensibilidade de três parametrizações de microfísica, sendo que os resultados encontrados não mostram alterações significativas aos resultados encontrados. Além disso, a introdução de um novo conjunto de dados de uso do solo tornou possível realizar simulações usando modelos urbanos acoplados. Assim, de forma a estudar a sensibilidade a estes modelos considerou-se um caso de estudo sobre a região de Lisboa. Ao utilizar um modelo urbano verificou-se que sobre a região urbana existe um arrefecimento à superfície quando comparando com as simulações de controlo. Além disso verificou-se uma grande diferença no escoamento e na energia turbulenta produzida sobre esta zona. Estas diferenças podem por sua vez intaragem com ondas gravíticas, alterando a sua fase e amplitude. Além disso, ao comparar os resultados com dados observados verificou-se que, em geral, não existe melhoria na performance do modelo para este caso de estudo. No entanto o uso do modelo urbano BEP melhora significativamente os resultados relativos à altura da camada de mistura.
Through the years, the advances in satellite technology made feasible the acquisition of information about the Earth surface, such as elevation and land use, with great detail and resolution. This information can be included in numerical atmospheric models, updating and giving them more details about the lower boundary. Given so, this work aims to study the sensitivity of the Weather Research and Forecast model to three different topography datasets as well as two different land use datasets. A test case study in which topography driven precipitation was dominant over Madeira Island was considered. Overall, results show that there is no enhancement of model skill when using higher resolution topography or land use. However, there is a higher model skill simulating precipitation on Madeira leeward and wind flow windward. Additionally, given the nature of this event, a sensitivity test was also performed considering three different microphysics parametrizations. This test showed that the choice of the microphysics parametrizations does not significantly change the results found for this event. Furthermore, the introduction of a new land use dataset turned possible to perform simulations using Urban Canopy Models. Therefore, the sensitivity of the model to these urban parametrizations was also performed. In this work, a case study for the Lisbon region was chosen and showed that the simulations that used a urban canopy model presented a cooling in the urban region. Moreover, larger changes were observed for wind flow and turbulence kinetic energy over the area. In addition, it was shown that these could change the phase and amplitude of gravity waves that were generated in the region. When comparing to observed data it was seen that there is no enhancement of model skill when using these models. However, the planetary boundary layer is better represent by BEP urban model.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Lower boundary of clouds"

1

Mouskos, Michael. Droplet growth in turbulent boundary layer clouds. Manchester: UMIST, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Martin, G. M. The interaction netween cumulus clouds and warm stratocumulus clouds in the marine boundary layer. Manchester: UMIST, 1995.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Gultepe, Ismail, ed. Fog and Boundary Layer Clouds: Fog Visibility and Forecasting. Basel: Birkhäuser Basel, 2007. http://dx.doi.org/10.1007/978-3-7643-8419-7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Coster, Colette De. Two-point boundary value problems: Lower and upper solutions. Amsterdam: Elsevier, 2006.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Patrick, Habets, ed. Two-point boundary value problems: Lower and upper solutions. Amsterdam: Elsevier, 2006.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Coster, Colette De. Two-point boundary value problems: Lower and upper solutions. Amsterdam: Elsevier, 2006.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Bryant, Laurie J. Non-dinosaurian lower vertebrates across the Cretaceous-Tertiary boundary. Berkeley, DC: University of California Press, 1989.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Nat︠s︡ionalen arkheologicheski institut i muzeĭ (Bŭlgarska akademii︠a︡ na naukite). The Lower Danube Roman Limes (1st - 6th c. AD). Sofia: National Archaeological Institute and Museum, Bulgarian Academy of Sciences, 2012.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Non-dinosaurian lower vertebrates across the Cretaceous-Tertiary boundary in northeastern Montana. Berkeley: University of California Press, 1989.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

Moczydlowska, Malgorzata. Acritarch biostratigraphy of the Lower Cambrian and the Precambrian--Cambrian boundary in southeastern Poland. Oslo: Universitetsforlaget, 1991.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Lower boundary of clouds"

1

Lohmann, Ulrike. "Marine boundary layer clouds." In Surface Ocean—Lower Atmosphere Processes, 57–68. Washington, D. C.: American Geophysical Union, 2009. http://dx.doi.org/10.1029/2008gm000761.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Stull, Roland B. "Boundary Layer Clouds." In An Introduction to Boundary Layer Meteorology, 545–85. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-3027-8_13.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Dickman, R. L., T. H. Jarrett, and W. Herbst. "Probing the Lower Main Sequence with Molecular Clouds." In Submillimetre Astronomy, 171–72. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-015-6850-0_62.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Lee, Xuhui. "Tracer Diffusion in the Lower Boundary Layer." In Springer Atmospheric Sciences, 121–48. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-60853-2_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Ginoux, Nicolas. "Lower eigenvalue estimates on compact manifolds with boundary." In The Dirac Spectrum, 69–75. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-01570-0_4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Akin-Bohner, Elvan, Ferhan Merdivenci Atici, and Billûr Kaymakçalan. "Lower and Upper Solutions of Boundary Value Problems." In Advances in Dynamic Equations on Time Scales, 165–88. Boston, MA: Birkhäuser Boston, 2003. http://dx.doi.org/10.1007/978-0-8176-8230-9_6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Plekhanova, Marina V., and Guzel D. Baybulatova. "Semilinear Equations in Banach Spaces with Lower Fractional Derivatives." In Nonlinear Analysis and Boundary Value Problems, 81–93. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-26987-6_6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Sugiyama, Takuya. "Ionic Nucleation of Ice Particles in Noctilucent Clouds." In The Upper Mesosphere and Lower Thermosphere: A Review of Experiment and Theory, 209–14. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/gm087p0209.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Xu, Zezhong, Cheng Qian, Xianju Fei, Yanbing Zhuang, Shibo Xu, and Reinhard Klette. "Boundary Extraction of Planar Segments from Clouds of Unorganised Points." In Lecture Notes in Computer Science, 209–22. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-41404-7_15.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Liu, Xian-Feng, and Adam M. Dziewonski. "Global analysis of shear wave velocity anomalies in the lower-most mantle." In The Core‐Mantle Boundary Region, 21–36. Washington, D. C.: American Geophysical Union, 1998. http://dx.doi.org/10.1029/gd028p0021.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Lower boundary of clouds"

1

Che, Bangxiang, and Dazhuan Wu. "Study on Vortex Generators for Control of Attached Cavitation." In ASME 2017 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/fedsm2017-69405.

Full text
Abstract:
Attached cavitation is a type of common cavitation phenomenon in fluid machinery. It is important to develop methods to control its generation. From the view of cavitation inception, the generation of attached cavitation is greatly influenced by the separated boundary layer upstream of cavitation detachment. In this research, a row of microscopic delta-shaped counter-rotating vortex generators (VGs) was applied on the leading edge of the NACA0015 hydrofoil in order to suppress the boundary layer separation and then suppress the generation of attached cavitation. The application of VGs fixed the position of cavitation inception on hydrofoil thus the sheet cavitation became more stable and the cloud cavity shed from hydrofoil with trim trailing edge more regularly. It was found that cavitation inception always appeared adjacent to VGs due to the low pressure in the corner of streamwise vortices induced by VGs. Hydrofoil with VGs showed an entirely different cavitation morphology on the leading edge. A row of separate microscopic vortex cavitation was induced by the counter-rotating vortices firstly. With the lower the height of VGs, the longer the length of these vortex cavitation due to the weaker interaction between vortices and main flow. Following the vortex cavitation, the attached cavitation was developing, but without typical “finger” structure anymore.
APA, Harvard, Vancouver, ISO, and other styles
2

Tatarov, Boyan I., Nikolai I. Kolev, Boiko K. Kaprielov, and Ivan N. Kolev. "Lidar observation of planetary boundary-layer clouds." In 12th International School on Quantum Electronics Laser Physics and Applications, edited by Peter A. Atanasov, Alexander A. Serafetinides, and Ivan N. Kolev. SPIE, 2003. http://dx.doi.org/10.1117/12.519497.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Sha, Zhengchuan, Qing Zhu, Yiping Chen, Cheng Wang, Abdul Nurunnabi, and Jonathan Li. "A Boundary-Enhanced Supervoxel Method for 3D Point Clouds." In IGARSS 2020 - 2020 IEEE International Geoscience and Remote Sensing Symposium. IEEE, 2020. http://dx.doi.org/10.1109/igarss39084.2020.9323330.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Bernstein, Ben C., Frank Mcdonough, and Cory Wolff. "A Regional Comparison of Icing Conditions in Boundary Layer Clouds." In SAE 2011 International Conference on Aircraft and Engine Icing and Ground Deicing. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2011. http://dx.doi.org/10.4271/2011-38-0021.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Nguyen, Van Sinh, Trong Hai Trinh, and Manh Ha Tran. "Hole Boundary Detection of a Surface of 3D Point Clouds." In 2015 International Conference on Advanced Computing and Applications (ACOMP). IEEE, 2015. http://dx.doi.org/10.1109/acomp.2015.12.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Villalonga, Joan, Susan L. Beveridge, Marcos Paulo Araujo Da Silva, Robin L. Tanamachi, Francesc Rocadenbosch, David D. Turner, and Stephen J. Frasier. "Convective boundary-layer height estimation from combined radar and Doppler lidar observations in VORTEX-SE." In Remote Sensing of Clouds and the Atmosphere XXV, edited by Adolfo Comerón, Evgueni I. Kassianov, Klaus Schäfer, Richard H. Picard, Konradin Weber, and Upendra N. Singh. SPIE, 2020. http://dx.doi.org/10.1117/12.2576046.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Rocadenbosch, Francesc, Robin L. Tanamachi, Marcos Paulo Araujo Da Silva, Joan Villalonga, Stephen J. Frasier, and David D. Turner. "Atmospheric boundary layer height disambiguation using synergistic remote sensing observations: case examples from VORTEX-SE." In Remote Sensing of Clouds and the Atmosphere XXV, edited by Adolfo Comerón, Evgueni I. Kassianov, Klaus Schäfer, Richard H. Picard, Konradin Weber, and Upendra N. Singh. SPIE, 2020. http://dx.doi.org/10.1117/12.2576093.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Cespedes, Jonnathan, Carlos A. Melo, and John H. Reina. "A first measurement of the planetary boundary layer top in Cali-Colombia: elastic LiDAR application." In Remote Sensing of Clouds and the Atmosphere XIII, edited by Adolfo Comerón, Evgueni I. Kassianov, Klaus Schäfer, Richard H. Picard, and Konradin Weber. SPIE, 2018. http://dx.doi.org/10.1117/12.2503534.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Liu, Xiaoqin, Zaihong Hou, Laian Qin, and Ningquan Weng. "A portable imaging lidar for lower boundary layer atmospheric measurement." In SPIE Remote Sensing, edited by Upendra N. Singh and Doina N. Nicolae. SPIE, 2015. http://dx.doi.org/10.1117/12.2195614.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Barros, Rui, Lydia Yatcheva, Sarah Keary Andreas Zepp, and Szymon Gladysz. "Monostatic system for turbulence measurement in the lower boundary layer." In Adaptive Optics: Analysis, Methods & Systems. Washington, D.C.: OSA, 2015. http://dx.doi.org/10.1364/aoms.2015.jw4f.3.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Lower boundary of clouds"

1

Orchard, M. J., and H. Bucher. Conodont - Ammonoid Intercalibration Around the Lower - Middle Triassic Boundary: Nevadan Clocks Help Tell British Columbian Time. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1992. http://dx.doi.org/10.4095/133566.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Orville, Harold D. The Numerical Simulation of Marine Boundary Layer Clouds. Fort Belvoir, VA: Defense Technical Information Center, January 1993. http://dx.doi.org/10.21236/ada273669.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Albrecht, Bruce. Aerosol-Cloud-Drizzle-Turbulence Interactions in Boundary Layer Clouds. Fort Belvoir, VA: Defense Technical Information Center, September 2009. http://dx.doi.org/10.21236/ada531259.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Albrecht, Bruce. Aerosol-Cloud-Drizzle-Turbulence Interactions In Boundary Layer Clouds. Fort Belvoir, VA: Defense Technical Information Center, September 2008. http://dx.doi.org/10.21236/ada532783.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Albrecht, Bruce. Aerosol-Cloud-Drizzle-Turbulence Interactions in Boundary Layer Clouds. Fort Belvoir, VA: Defense Technical Information Center, September 2010. http://dx.doi.org/10.21236/ada541857.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Albrecht, Bruce. Aerosol-Cloud-Drizzle-Turbulence Interactions in Boundary Layer Clouds. Fort Belvoir, VA: Defense Technical Information Center, September 2012. http://dx.doi.org/10.21236/ada575522.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Albrecht, Bruce. Aerosol-Cloud-Drizzle-Turbulence Interactions in Boundary Layer Clouds. Fort Belvoir, VA: Defense Technical Information Center, September 2012. http://dx.doi.org/10.21236/ada574045.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Albrecht, Bruce. Aerosol-Cloud-Drizzle-Turbulence Interactions in Boundary Layer Clouds. Fort Belvoir, VA: Defense Technical Information Center, September 2011. http://dx.doi.org/10.21236/ada557114.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Albrecht, Bruce. Aerosol-Cloud-Drizzle-Turbulence Interactions in Boundary Layer Clouds. Fort Belvoir, VA: Defense Technical Information Center, September 2013. http://dx.doi.org/10.21236/ada598037.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Kogan, Yefim L. Midlatitude Aerosol-Cloud-Radiation Feedbacks in Marine Boundary Layer Clouds. Fort Belvoir, VA: Defense Technical Information Center, September 2008. http://dx.doi.org/10.21236/ada532932.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Lower boundary of clouds' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography