Single-column Model Simulations of Arctic Cloudiness and Surface Radiative Fluxes During the Surface Heat Budget of Arctic (SHEBA) Experiment

Single-column Model Simulations of Arctic Cloudiness and Surface Radiative Fluxes During the Surface Heat Budget of Arctic (SHEBA) Experiment PDF Author: Cécile Hannay
Publisher:
ISBN:
Category : Atmospheric radiation
Languages : en
Pages : 120

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Book Description
"We evaluate the ability of a typical cloud parameterization from a global model (CCM3 from NCAR) to simulate the Arctic cloudiness and longwave radiative fluxes during wintertime. Simulations are conducted with a Single-Column model (SCM) forced with observations and reanalysis data from the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment. Typically, the SCM overestimates the Arctic cloud fraction and the downwelling longwave flux. Moreover, the SCM does not capture accurately the temperature and moisture profiles, and the surface flux fields. Relaxing temperature and moisture profiles to observed values dramatically improves the simulations. This suggests that the cloud parameterization of CCM3 is suitable for Arctic clouds, as long as the temperature and moisture fields are captured correctly. Sensitivities studies show that the cloud fraction is not very sensitive to cloud type, ice effective radius, ice liquid ratio amount and uncertainty of the advective forcing"--Leaf 3.

Single-column Model Simulations of Arctic Cloudiness and Surface Radiative Fluxes During the Surface Heat Budget of Arctic (SHEBA) Experiment

Single-column Model Simulations of Arctic Cloudiness and Surface Radiative Fluxes During the Surface Heat Budget of Arctic (SHEBA) Experiment PDF Author: Cécile Hannay
Publisher:
ISBN:
Category : Atmospheric radiation
Languages : en
Pages : 120

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Book Description
"We evaluate the ability of a typical cloud parameterization from a global model (CCM3 from NCAR) to simulate the Arctic cloudiness and longwave radiative fluxes during wintertime. Simulations are conducted with a Single-Column model (SCM) forced with observations and reanalysis data from the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment. Typically, the SCM overestimates the Arctic cloud fraction and the downwelling longwave flux. Moreover, the SCM does not capture accurately the temperature and moisture profiles, and the surface flux fields. Relaxing temperature and moisture profiles to observed values dramatically improves the simulations. This suggests that the cloud parameterization of CCM3 is suitable for Arctic clouds, as long as the temperature and moisture fields are captured correctly. Sensitivities studies show that the cloud fraction is not very sensitive to cloud type, ice effective radius, ice liquid ratio amount and uncertainty of the advective forcing"--Leaf 3.

Results for Sheba/Fire

Results for Sheba/Fire PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781721569908
Category :
Languages : en
Pages : 38

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Book Description
The Atmospheric Research Laboratory's Radiation Measurement System (RAMS) was on the NCAR C-130 aircraft in May and July 1998, collecting radiometric data on the science flights conducted in the vicinity of the Surface Heat Budget of the Arctic Ocean (SHEBA) ship. These measurements were part of the FIRE Arctic Cloud Experiment (FIRE ACE). Analysis of some of the data focused on the absorption, reflection, and transmittance of Arctic clouds, especially compared to model results. In order to assess the absorption of solar radiation by the clear and cloudy atmosphere in the Arctic the measurements from the radiometers were combined in pairs of above-cloud segments and below-cloud segments. To get these pairs, the data for all sixteen of the flights (8 in May and 8 in July) were examined for occurrences of low-altitude segments in proximity to high-altitude segments. The low-altitude data are then treated as measurements of the bottom of a layer and the high-altitude data are taken as measurements of the top of the layer. With measurements of the upwelling and downwelling irradiances above and below a layer one can determine the reflectance, transmittance, and absorptance of the layer. Attachment: Doelling, D.R., P. Minnis, D.A. Spangenberg, V. Chakrapani, A. Mahesh, S.K. Pope, and F.P.J. Valero, Cloud radiative forcing at the top of the atmosphere during FIRE ACE derived from AVHRR data, J. Geophys. Res. 106, 15,279-15,296,2001. Minnis, P., D.R. Doelling, D.A. Spangenberg, A. Mahesh, S.K. Pope, and F.P.J. Valero, AVHRR-derived cloud radiative forcing over the ARM NSA and SHEBA site during FIRE ACE, abstract submitted to the ARM Science Team Meeting, San Antonio, TX, M a . 13-17,2000. Pope, S.K., and F.P.J. Valero, Measured and modeled radiometric fluxes in the Arctic during FIRE-ACE, presented as a poster at the American Geophysical Union meeting, San Francisco, CA, Dec. 13-17, 1999. Pope, S.K., and F.P.J. Valero, Measured and modeled radiometric fluxes in the Arctic

Mixed-Phase Clouds

Mixed-Phase Clouds PDF Author: Constantin Andronache
Publisher: Elsevier
ISBN: 012810550X
Category : Science
Languages : en
Pages : 302

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Book Description
Mixed-Phase Clouds: Observations and Modeling presents advanced research topics on mixed-phase clouds. As the societal impacts of extreme weather and its forecasting grow, there is a continuous need to refine atmospheric observations, techniques and numerical models. Understanding the role of clouds in the atmosphere is increasingly vital for current applications, such as prediction and prevention of aircraft icing, weather modification, and the assessment of the effects of cloud phase partition in climate models. This book provides the essential information needed to address these problems with a focus on current observations, simulations and applications. - Provides in-depth knowledge and simulation of mixed-phase clouds over many regions of Earth, explaining their role in weather and climate - Features current research examples and case studies, including those on advanced research methods from authors with experience in both academia and the industry - Discusses the latest advances in this subject area, providing the reader with access to best practices for remote sensing and numerical modeling

Linking Atmospheric Synoptic Transport, Cloud Phase, Surface Energy Fluxes, and Sea-ice Growth: Observations of Midwinter SHEBA Conditions

Linking Atmospheric Synoptic Transport, Cloud Phase, Surface Energy Fluxes, and Sea-ice Growth: Observations of Midwinter SHEBA Conditions PDF Author: Donald K. Perovich
Publisher:
ISBN:
Category : Arctic regions
Languages : en
Pages : 24

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Book Description
Observations from the Surface Heat Budget of the Arctic Ocean (SHEBA) project are used to describe a sequence of events linking midwinter long-range advection of atmospheric heat and moisture into the Arctic Basin, formation of supercooled liquid water clouds, enhancement of net surface energy fluxes through increased downwelling longwave radiation, and reduction in near-surface conductive heat flux loss due to a warming of the surface, thereby leading to a reduction in sea-ice bottom growth. The analyses provide details of two events during Jan. 1–12, 1998, one entering the Arctic through Fram Strait and the other from northeast Siberia; winter statistics extend the results. Both deep, precipitating frontal clouds and post-frontal stratocumulus clouds impact the surface radiation and energy budget. Cloud liquid water, occurring preferentially in stratocumulus clouds extending into the base of the inversion, provides the strongest impact on surface radiation and hence modulates the surface forcing, as found previously. The observations suggest a minimum water vapor threshold, likely case dependent, for producing liquid water clouds. Through responses to the radiative forcing and surface warming, this cloud liquid water also modulates the turbulent and conductive heat fluxes, and produces a thermal wave penetrating into the sea ice. About 20–33 % of the observed variations of bottom ice growth can be directly linked to variations in surface conductive heat flux, with retarded ice growth occurring several days after these moisture plumes reduce the surface conductive heat flux. This sequence of events modulate pack-ice wintertime environmental conditions and total ice growth, and has implications for the annual sea-ice evolution, especially for the current conditions of extensive thinner ice.

The Arctic Climate System

The Arctic Climate System PDF Author: Mark C. Serreze
Publisher: Cambridge University Press
ISBN: 1139445383
Category : Science
Languages : en
Pages : 413

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Book Description
The Arctic can be viewed as an integrated system, characterised by intimate couplings between its atmosphere, ocean and land, linked in turn to the larger global system. This comprehensive, up-to-date assessment begins with an outline of early Arctic exploration and the growth of modern research. Using an integrated systems approach, subsequent chapters examine the atmospheric heat budget and circulation, the surface energy budget, the hydrologic cycle and interactions between the ocean, atmosphere and sea ice cover. Reviews of recent directions in numerical modelling and the characteristics of past Arctic climates set the stage for detailed discussion of recent climate variability and trends, and projected future states. Throughout, satellite remote sensing data and results from recent major field programs are used to illustrate key processes. The Arctic Climate System provides a comprehensive and accessible overview of the subject for researchers and advanced students in a wide range of disciplines.

Witness the Arctic

Witness the Arctic PDF Author:
Publisher:
ISBN:
Category : Arctic regions
Languages : en
Pages : 222

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Book Description


The Arctic Climate System

The Arctic Climate System PDF Author: Mark C. Serreze
Publisher: Cambridge University Press
ISBN: 113995248X
Category : Science
Languages : en
Pages : 449

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Book Description
This second edition brings this definitive book up to date with the many advances in our understanding of Arctic climate since the first edition was published in 2005. The book has also been extensively reorganized to weave issues of Arctic change throughout the text, rather than confining them to a single chapter. It is the first to provide an integrated assessment of the Arctic climate system, recognizing that a true understanding of how the Arctic functions lies in appreciating the interactions among its various components. The book begins with a historical perspective, followed by discussion of the basic physical and climatic characteristics of the Arctic. Following a review of past climates (paleoclimates), the book closes with an assessment of the Arctic's uncertain future. Though targeted mainly at advanced students and researchers, this book is accessible to anyone with an interest in the Arctic and a basic understanding of climate science.

SHEBA

SHEBA PDF Author: Tarri Joyner
Publisher:
ISBN:
Category : Drifting ice stations
Languages : en
Pages : 174

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Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 624

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Dissertation Abstracts International

Dissertation Abstracts International PDF Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 774

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Book Description