Download or read book Snow Particle Size Investigations Using Digital Image Analysis Implications for Ground Observations and Remote Sensing of Snow written by Susanne Ingvander and published by . This book was released on 2011 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Snow and Climate written by Richard L. Armstrong and published by Cambridge University Press. This book was released on 2008-04-24 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the prevailing state of snow-climate science for researchers and advanced students.
Download or read book Earth Resources written by and published by . This book was released on 1983 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Snow Depth and Snow Extent Using VHRR Data from the NOAA 2 Satellite written by David F. McGinnis and published by . This book was released on 1975 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes field testing (in south-eastern U.S.A.) of hypothesis that brightness of snow received as reflected radiation by visible-band sensors on satellites is possible indication of snow depth.
Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1991 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Snow Properties Retrieval Using Passive Microwave Observations written by Nastaran Saberi and published by . This book was released on 2019 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seasonal snow cover, the second-largest component of the cryosphere, is crucial in controlling the climate system, through its important role in modifying Earth's albedo. The temporal variability of snow extent and its physical properties in the seasonal cycle also make up a significant element to the cryospheric energy balance. Thus, seasonal snowcover should be monitored not only for its climatological impacts but also for its rolein the surface-water supply, ground-water recharge, and its insolation properties at local scales. Snowpack physical properties strongly influence the emissions from the substratum, making feasible snow property retrieval by means of the surface brightness temperature observed by passive microwave sensors. Depending on the observing spatial resolution, the time series records of daily snow coverage and a snowpacks most-critical properties such as the snow depth and snow water equivalent (SWE) could be helpful in applications ranging from modeling snow variations in a small catchment to global climatologic studies. However, the challenge of including spaceborne snow water equivalent (SWE) products in operational hydrological and hydroclimate modeling applications is very demanding with limited uptake by these systems. Various causes have been attributed to this lack of up-take but most stem from insufficient SWE accuracy. The root causes of this challenge includes the coarse spatial resolution of passive microwave (PM) observations that observe highly aggregated snowpack properties at the spaceborne scale, and inadequacies during the retrieval process that are caused by uncertainties with the forward emission modeling of snow and challenges to find robust parameterizations of the models. While the spatial resolution problem is largely in the realm of engineering design and constrained by physical restrictions, a better understanding of the whole range of retrieval methodologies can provide the clarity needed to move the thinking forward in this important field. Following a review on snow depth and SWE retrieval methods using passive microwave remote sensing observations, this research employs a forward emission model to simulate snowpacks emission and compare the results to the PM airborne observations. Airborne radiometer observations coordinated with ground-based in-situ snow measurements were acquired in the Canadian high Arctic near Eureka, NT, in April 2011. The observed brightness temperatures (Tb) at 37 GHz from typical moderate density dry snow in mid-latitudes decreases with increasing snow water equivalent (SWE) due to the volume scattering of the ground emissions by the overlying snow. At a certain point, however, as SWE increases, the emission from the snowpack offsets the scattering of the sub-nivean emission. In tundra snow, the Tb slope reversal occurs at shallower snow thicknesses. While it has been postulated that the inflection point in the seasonal time series of observed Tb V 37 GHz of tundra snow is controlled by the formation of a thick wind slab layer, the simulation of this effect has yet to be confirmed. Therefore, the Dense Media Radiative Transfer Theory forMulti Layered (DMRT-ML) snowpack is used to predict the passive microwave response from airborne observations over shallow, dense, slab-layered tundra snow. The DMRT-ML was parameterized with the in-situ snow measurements using a two-layer snowpack and run in two configurations: a depth hoar and a wind slab dominated pack. Snow depth retrieval from passive microwave observations without a-priori information is a highly underdetermined system. An accurate estimate of snow depth necessitates a-priori information of snowpack properties, such as grain size, density, physical temperature and stratigraphy, and, very importantly, a minimization of this a prior information requirement. In previous studies, a Bayesian Algorithm for Snow Water Equivalent (SWE) Estimation (BASE) have been developed, which uses the Monte Carlo Markov Chain (MCMC) method to estimate SWE for taiga and alpine snow from 4-frequency ground-based radiometer Tb. In our study, BASE is used in tundra snow for datasets of 464 footprints inthe Eureka region coupled with airborne passive microwave observations-the same fieldstudy that forward modelling was evaluated. The algorithm searches optimum posterior probability distribution of snow properties using a cost function between physically based emission simulations and Tb observations. A two-layer snowpack based on local snow cover knowledge is assumed to simulate emission using the Dense Media Radiative Transfer-Multi Layered (DMRT-ML) model. Overall, the results of this thesis reinforce the applicability of a physics-based emission model in SWE retrievals. This research highlights the necessity to consider the two-part emission characteristics of a slab-dominated tundra snowpack and suggests performing inversion in a Bayesian framework.
Download or read book Optical Measurements on Snow written by Malcolm Mellor and published by . This book was released on 1965 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spectral extinction measurements for the visual range were made on homogeneous snow samples prepared under controlled conditions, with snow density and grain size as variables. Comparative measurements were made on coarse-grained natural snow. Extinction coefficient nu was in the range 0.8 to 1.7/cm for fine-grained dense snow, and 0.16 to 0.37/cm for the coarse-grained snow. In the fine-grained snow, where scattering is thought to be the dominant attenuating process, there is a general decline in nu as wavelength lambda increases from 0.4 to 0.7 microns. In the coarse-grained snow, where absorption becomes significant, spectral selection was slight, with a weak minimum in the region 0.5 to 0.6 microns. When nu is related to density it must have a maximum value; limited data for fine-grained snow show this maximum in the density range 0.45 to 0.60 g/cc, and the density for maximum extinction is inversely related to wavelength. For a given density nu decreases as grain size increases, the rate of change varying with wavelength. Spectral reflectance measurements on natural snow are reported, and attenuation data are interpreted to give surface reflectivity for fine-grained snow. Diffuse reflection from fine-grained snow is believed to have little spectral dependence in the visual range, but with coarse-grained snow reflectance is expected to become inversely dependent on wavelength. It is suggested that optical principles might be applied in the measurement of snow structure, and also for remote sensing of snow-covered terrain. (Author).
Download or read book Snow Cover Measurements and Areal Assessment of Precipitation and Soil Moisture written by Boris Sevruk and published by World Meteorological Organization. This book was released on 1992 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geographical Abstracts written by and published by . This book was released on 1987 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessing the Ability of Using Multi angular CHRIS PROBA Data for Estimating Snow Cover and Snow Properties in an Alpine Area written by Jan Martijn Roetman and published by . This book was released on 2009 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Earth Resources written by and published by . This book was released on 1978 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International Aerospace Abstracts (IAA).
Download or read book Cooperative Snow Investigations written by and published by . This book was released on 1950 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Earth Resources A Continuing Bibliography with Indexes written by and published by . This book was released on 1984 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Principles of Snow Hydrology written by David R. DeWalle and published by Cambridge University Press. This book was released on 2008-07-03 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: Principles of Snow Hydrology describes the factors that control the accumulation, melting and runoff of water from seasonal snowpacks over the surface of the earth. The book addresses not only the basic principles governing snow in the hydrologic cycle, but also the latest applications of remote sensing, and techniques for modeling streamflow from snowmelt across large mixed land-use river basins. Individual chapters are devoted to climatology and distribution of snow, snowpack energy exchange, snow chemistry, ground-based measurements and remote sensing of snowpack characteristics, snowpack management, and modeling snowmelt runoff. Many chapters have review questions and problems with solutions available online. This book is a reference book for practicing water resources managers and a text for advanced hydrology and water resources courses which span fields such as engineering, earth sciences, meteorology, biogeochemistry, forestry and range management, and water resources planning.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2001 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt:
