Download or read book Cloudy Boundary Layers of the Arctic written by James O. Pinto and published by . This book was released on 1997 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evolution of a Storm driven Cloudy Boundary Layer in the Arctic written by and published by . This book was released on 2003 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cloudy boundary layer under stormy conditions during the summertime Arctic has been studied using observation from the SHEBA experiment and large-eddy simulations (LES). On 29 July 1998, a stable Arctic cloudy boundary layer event was observed after passage of a synoptic low. The local dynamic and thermodynamic structure of the boundary layer was determined from aircraft measurement including analysis of turbulence, cloud microphysics and radiative properties. After the upper cloud layer advected over the existing cloud layer, the turbulent kinetic energy budget indicated that the cloud layer below 200 m was maintained predominantly by shear production. Observations of longwave radiation showed that cloud top cooling at the lower cloud top has been suppressed by radiative effects of the upper cloud layer. Our LES results demonstrate the importance of the combination of shear mixing near the surface and radiative cooling at the cloud top in the storm-driven cloudy boundary layer. Once the low-level cloud reaches a certain height, depending on the amount of cloud-top cooling, the two sources of TKE production begin to separate in space under continuous stormy conditions, suggesting one possible mechanism for the cloud layering. The sensitivity tests suggest that the storm-driven cloudy boundary layer is flexibly switched to the shear-driven system due to the advection of upper clouds or the buoyantly driven system due to the lack of the wind shear. A comparison is made of this storm-driven boundary layer with the buoyantly driven boundary layer previously described in the literature.
Download or read book Modelling the mean and turbulent structure of the summertime Arctic cloudy boundary layer written by K.L. McINNES and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interactions of the Cloudy Arctic Boundary Layer with Variable Surface Conditions and Large Scale Circulations written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-16 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our project included a variety of activities, ranging from model development to data manipulation and even participation in the SHEBA and FIRE field experiments. The following sections outline the work accomplished under these tasks. A collection of reprints is attached to this report. Randell, David A. Langley Research Center
Download or read book Cloud Scale Numerical Modeling of the Arctic Boundary Layer written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-23 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interactions between sea ice, open ocean, atmospheric radiation, and clouds over the Arctic Ocean exert a strong influence on global climate. Uncertainties in the formulation of interactive air-sea-ice processes in global climate models (GCMs) result in large differences between the Arctic, and global, climates simulated by different models. Arctic stratus clouds are not well-simulated by GCMs, yet exert a strong influence on the surface energy budget of the Arctic. Leads (channels of open water in sea ice) have significant impacts on the large-scale budgets during the Arctic winter, when they contribute about 50 percent of the surface fluxes over the Arctic Ocean, but cover only 1 to 2 percent of its area. Convective plumes generated by wide leads may penetrate the surface inversion and produce condensate that spreads up to 250 km downwind of the lead, and may significantly affect the longwave radiative fluxes at the surface and thereby the sea ice thickness. The effects of leads and boundary layer clouds must be accurately represented in climate models to allow possible feedbacks between them and the sea ice thickness. The FIRE III Arctic boundary layer clouds field program, in conjunction with the SHEBA ice camp and the ARM North Slope of Alaska and Adjacent Arctic Ocean site, will offer an unprecedented opportunity to greatly improve our ability to parameterize the important effects of leads and boundary layer clouds in GCMs. Krueger, Steven K. Langley Research Center NAG1-1718
Download or read book Modeling of Arctic Stratus Cloud Formation and the Maintenance of the Cloudy Arctic Boundary Layer written by Chʻiu-chʻing Chang and published by . This book was released on 1999 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The formation of Arctic stratus clouds (ASC) and the maintenance of the cloudy Arctic boundary layer are studied with two models: a one-dimensional radiative-convective model and a three-dimensional large eddy simulation (LES) model. The one-dimensional radiative-convective model consists of a comprehensive radiative module, a cloud parameterization with detailed microphysics and a convective adjustment scheme. The model is designed specifically for studying ASC formation. With this model, the roles of radiation and cloud microphysics in the formation of ASCs and multiple cloud layers are investigated. The simulations reproduce both single and multiple cloud layers that were observed with inversions of temperature and humidity occurring near the cloud top. The detailed cloud microstructure produced by the model also compares well with the observations. The physics of the formation of both single and multiple cloud layers is investigated. Radiative cooling plays a key role during the initial stage of cloud formation in a atmosphere. It leads to a continual temperature decrease promoting water vapor condensation on available cloud condensation nuclei. The vertical distribution of humidity and temperature determines the radiative cooling and eventually where and when the cloud forms. The observed temperature inversion may also be explained by radiative cooling. The three-dimensional LES model is adopted to evaluate the one-dimensional model, especially the convective adjustment scheme. The advantages and limitations of the one-dimensional model are discussed. The LES results suggest that the convective adjustment scheme is capable of capturing the main features of the vertical heat and moisture fluxes in the cloudy Arctic boundary layer. The LES model is also used to investigate the maintenance of the cloudy Arctic boundary layer. The turbulence in the cloudy Arctic boundary layer is primarily maintained by the bouyancy effect due to the cloud top cooling. It is found that weak large scale downward motion aids in cloud development and maintenance"--3.
Download or read book Radiative Interactions Between Arctic Sea Ice and Boundary Layer Stratus Clouds written by Elizabeth Eby Ebert and published by . This book was released on 1984 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Atmospheric Boundary Layer written by J. R. Garratt and published by Cambridge University Press. This book was released on 1994-04-21 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book gives a comprehensive and lucid account of the science of the atmospheric boundary layer (ABL). There is an emphasis on the application of the ABL to numerical modelling of the climate. The book comprises nine chapters, several appendices (data tables, information sources, physical constants) and an extensive reference list. Chapter 1 serves as an introduction, with chapters 2 and 3 dealing with the development of mean and turbulence equations, and the many scaling laws and theories that are the cornerstone of any serious ABL treatment. Modelling of the ABL is crucially dependent for its realism on the surface boundary conditions, and chapters 4 and 5 deal with aerodynamic and energy considerations, with attention to both dry and wet land surfaces and sea. The structure of the clear-sky, thermally stratified ABL is treated in chapter 6, including the convective and stable cases over homogeneous land, the marine ABL and the internal boundary layer at the coastline. Chapter 7 then extends the discussion to the cloudy ABL. This is seen as particularly relevant, since the extensive stratocumulus regions over the subtropical oceans and stratus regions over the Arctic are now identified as key players in the climate system. Finally, chapters 8 and 9 bring much of the book's material together in a discussion of appropriate ABL and surface parameterization schemes in general circulation models of the atmosphere that are being used for climate simulation.
Download or read book An Observation and Modeling Study of Arctic Multilayered Mixed phase Boundary Layer Clouds written by Hui Lai and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To better understand the dynamic and thermodynamic processes that form and maintain Arctic multilayered mixed-phase clouds, Moderate Resolution Imaging Spectroradiometer (MODIS) radiances, High Spectral Resolution Lidar (HSRL) backscatter, and Ka-band ARM zenith radar (KAZR) returns along with balloon-borne sounding thermodynamic profiles, were analyzed from 1-3 May 2013. The observations, together with ERA-Interim Reanalysis data, indicate that three cloud regimes were present during this period. Frontal clouds occurred in a north to south band with Barrow located on their eastern edge at 00:00 UTC 2 May. By mid-day the frontal clouds had moved into the Barrow region. A broad low-altitude stratus deck existed to the west and north of Barrow, advecting into the Barrow region by the end of 2 May as the frontal clouds cleared the region. The stratus deck remained over Barrow throughout 3 May and several days beyond it. Boundary layer cellular convection was the predominant cloud type in the vicinity of the low pressure to the east and north of Barrow on 1-2 May.On 2 May 2013 shallow single- and multi-layered, mixed-phase clouds observed by the HSRL and KAZR were present above Barrow, Alaska, leading at various times to pristine crystals, rimed crystals and aggregates of crystals at the surface. During this case study period, a weak surface trough was located to the north and east of Barrow with a high pressure ridge to its west. The associated surface front was located over Barrow and extended to the north over the Arctic Ocean. High spatial (250-m) pixel resolution MODIS radiances show low level cloud streets in the vicinity of Barrow and just to its east oriented perpendicular to the mean wind around 00:00 UTC 2 May. Low altitude cloud streets also existed to the west of Barrow at this time, though oriented parallel to the mean wind. Finally, additional cloud streets to the southwest of Barrow and perpendicular to the mean wind also were present but in the higher altitude frontal clouds. The low altitude cloud streets just to the east and west of Barrow, and under the frontal cloud layer, were the source of the multilayered clouds on this day; this study focused on the ones to the west. These cloud streets formed in an environment of strong vertical wind shear with an underlying shallow buoyant layer near the surface.The Weather and Research Forecasting (WRF) model was used to conduct mesoscale simulations for this day and the two surrounding ones. For the three-day period from 1-3 May 2013 the 27-km spatial grid spacing WRF model reproduced mesoscale geopotential height, wind, relative humidity and sea-level pressure fields similar to those contained in the (0.75 lat/lon) ERA-Interim Reanalysis. Moreover, the model was able to reproduce the three cloud systems evident in the observations: the low cloud-liquid stratus to the west of Barrow, the deep frontal cloud layer in the vicinity of Barrow, and the more convective cloud cells with heights in-between to the east of Barrow.In the WRF modeling approach six nested domains were used with horizontal grid spacings starting from 27 km and scaling down in ratios of 3 to 1, with the finest domain run in large eddy simulation mode at 111-m horizontal grid spacing in an attempt to capture the short (~ 1.5-km) wavelength of the cloud streets apparent in the satellite data. Model results show that warm air advection and surface radiative heating created enhanced near surface instability, providing the buoyancy necessary to drive the initial convection. These buoyant parcels entered the region of strong vertical shear, leading to Richardson numbers around 0.2 and the conditions favorable for the formation of roll clouds. The wavelengths of the roll clouds produced by the inner four nested domains varied from 33 km for the outermost 3-km domain to 1 km for the finest 0.111-km grid spacing domain. The finest grid spacing domain roll-cloud wavelengths were comparable to those observed by MODIS, illustrating the necessity of using a grid spacing sufficiently small to place at least 7 to 10 grid points across a roll in order to resolve it.
Download or read book Arctic mixed phase clouds Macro and microphysical insights with a numerical model written by Loewe, Katharina and published by KIT Scientific Publishing. This book was released on 2017-09-15 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work provides new insights into macro- and microphysical properties of Arctic mixed-phase clouds: first, by comparing semi-idealized large eddy simulations with observations; second, by dissecting the influences of different surface types and boundary layer structures on Arctic mixed- phase clouds; third, by elucidating the dissipation process; and finally by analyzing the main microphysical processes inside Arctic mixed-phase clouds.
Download or read book The Arctic Climate System written by Mark C. Serreze and published by Cambridge University Press. This book was released on 2005-10-13 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive, up-to-date assessment of the Arctic climate system for researchers and advanced students.
Download or read book Storm and Cloud Dynamics written by William R. Cotton and published by Academic Press. This book was released on 2010-12-21 with total page 826 pages. Available in PDF, EPUB and Kindle. Book excerpt: Storm and Cloud Dynamics focuses on the dynamics of clouds and of precipitating mesoscale meteorological systems. Clouds and precipitating mesoscale systems represent some of the most important and scientifically exciting weather systems in the world. These are the systems that produce torrential rains, severe winds including downburst and tornadoes, hail, thunder and lightning, and major snow storms. Forecasting such storms represents a major challenge since they are too small to be adequately resolved by conventional observing networks and numerical prediction models. Provides a complete treatment of clouds integrating the analysis of air motions with cloud structure, microphysics, and precipitation mechanics Describes and explains the basic types of clouds and cloud systems that occur in the atmosphere-fog, stratus, stratocumulus, altocumulus, altostratus, cirrus, thunderstorms, tornadoes, waterspouts, orographically induced clouds, mesoscale convection complexes, hurricanes, fronts, and extratropical cyclones Summarizes the fundamentals, both observational and theoretical, of atmospheric dynamics, thermodynamics, cloud microphysics, and radar meteorology, allowing each type of cloud to be examined in depth Integrates the latest field observations, numerical model simulations, and theory Supplies a theoretical treatment suitable for the advanced undergraduate or graduate level, as well as post-graduate
Download or read book Clear and Cloudy Boundary Layers written by and published by . This book was released on 1951 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics and Chemistry of the Arctic Atmosphere written by Alexander Kokhanovsky and published by Springer Nature. This book was released on 2020-01-29 with total page 723 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents current knowledge on chemistry and physics of Arctic atmosphere. Special attention is given to studies of the Arctic haze phenomenon, Arctic tropospheric clouds, Arctic fog, polar stratospheric and mesospheric clouds, atmospheric dynamics, thermodynamics and radiative transfer as related to the polar environment. The atmosphere-cryosphere feedbacks and atmospheric remote sensing techniques are presented in detail. The problems of climate change in the Arctic are also addressed.
Download or read book Symposium on Boundary Layers and Turbulence written by and published by . This book was released on with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Clouds and Their Climatic Impact written by Sylvia Sullivan and published by John Wiley & Sons. This book was released on 2023-12-19 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clouds and Their Climatic Impacts Clouds are an influential and complex element of Earth’s climate system. They evolve rapidly in time and exist over small spatial scales, but also affect global radiative balance and large-scale circulations. With more powerful models and extensive observations now at our disposal, the climate impact of clouds is receiving ever more research attention. Clouds and Their Climatic Impacts: Radiation, Circulation, and Precipitation presents an overview of our current understanding on various types of clouds and cloud systems and their multifaceted role in the radiative budget, circulation patterns, and rainfall. Volume highlights include: Interactions of aerosol with both liquid and ice clouds Surface and atmospheric cloud radiative feedbacks and effects Arctic, extratropical, and tropical clouds Cloud-circulation coupling at global, meso, and micro scales Precipitation efficiency, phase, and measurements The role of machine learning in understanding clouds and climate The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.
Download or read book Proceedings of the Fifth Atmospheric Radiation Measurement ARM Science Team Meeting written by and published by . This book was released on 1995 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:
