Download or read book Direct Insertion of NASA Airborne Snow Observatory Derived Snow Depth Time Series Into the ISnobal Energy Balance Snow Model written by Hans-Peter Marshall and published by . This book was released on 2018 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plain Language Summary: In regions that depend primarily on snow to support life, water availability is becoming an increasingly important topic. National Aeronautics and Space Administration (NASA)'s Airborne Snow Observatory (ASO) is a new platform for estimating the amount of water stored in mountain snowpacks. Since 2013, the ASO has combined detailed measurements of snow depth from an aircraft with snowpack density estimates from a physics‐based snow model to provide predictions of total snow water equivalent stored in the Tuolumne River Basin in the California Sierra Nevada. This work describes the process of updating the snow model using the measured ASO snow depths through a direct insertion process. When the distribution of all the snow in the basin is known more accurately, the model results are improved.
Download or read book UAV Photogrammetry and Remote Sensing written by Fernando Carvajal-Ramírez and published by MDPI. This book was released on 2021-09-06 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concept of remote sensing as a way of capturing information from an object without making contact with it has, until recently, been exclusively focused on the use of Earth observation satellites. The emergence of unmanned aerial vehicles (UAV) with Global Navigation Satellite System (GNSS) controlled navigation and sensor-carrying capabilities has increased the number of publications related to new remote sensing from much closer distances. Previous knowledge about the behavior of the Earth's surface under the incidence different wavelengths of energy has been successfully applied to a large amount of data recorded from UAVs, thereby increasing the special and temporal resolution of the products obtained. More specifically, the ability of UAVs to be positioned in the air at pre-programmed coordinate points; to track flight paths; and in any case, to record the coordinates of the sensor position at the time of the shot and at the pitch, yaw, and roll angles have opened an interesting field of applications for low-altitude aerial photogrammetry, known as UAV photogrammetry. In addition, photogrammetric data processing has been improved thanks to the combination of new algorithms, e.g., structure from motion (SfM), which solves the collinearity equations without the need for any control point, producing a cloud of points referenced to an arbitrary coordinate system and a full camera calibration, and the multi-view stereopsis (MVS) algorithm, which applies an expanding procedure of sparse set of matched keypoints in order to obtain a dense point cloud. The set of technical advances described above allows for geometric modeling of terrain surfaces with high accuracy, minimizing the need for topographic campaigns for georeferencing of such products. This Special Issue aims to compile some applications realized thanks to the synergies established between new remote sensing from close distances and UAV photogrammetry.
Download or read book Actionable Science of Global Environment Change written by Ziheng Sun and published by Springer Nature. This book was released on 2023-12-03 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume teaches readers how to sort through the vast mountain of climate and environmental science data to extract actionable insights. With the advancements in sensing technology, we now observe petabytes of data related to climate and the environment. While the volume of data is impressive, collecting big data for the sake of data alone proves to be of limited utility. Instead, our quest is for actionable data that can drive tangible actions and meaningful impact. Yet, unearthing actionable insights from the accumulated big data and delivering them to global stakeholders remains a burgeoning field. Although traditional data mining struggles to keep pace with data accumulation, scientific evolution has spurred the emergence of new technologies like numeric modeling and machine learning. These cutting-edge tools are now tackling grand challenges in climate and the environment, from forecasting extreme climate events and enhancing environmental productivity to monitoring greenhouse gas emissions, fostering smart environmental solutions, and understanding aerosols. Additionally, they model environmental-human interactions, inform policy, and steer markets towards a healthier and more environment-friendly direction. While there's no universal solution to address all these formidable tasks, this book takes us on a guided journey through three sections, enriched with chapters from domain scientists. Part I defines actionable science and explores what truly renders data actionable. Part II showcases compelling case studies and practical use scenarios, illustrating these principles in action. Finally, Part III provides an insightful glimpse into the future of actionable science, focusing on the pressing climate and environmental issues we must confront. Embark on this illuminating voyage with us, where big data meets practical research, and discover how our collective efforts move us closer to a sustainable and thriving future. This book is an invitation to unlock the mysteries of our environment, transforming data into decisive action for generations to come.
Download or read book Lakes and Watersheds in the Sierra Nevada of California written by John M. Melack and published by University of California Press. This book was released on 2020-12-01 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Sierra Nevada, California’s iconic mountain range, harbors thousands of remote high-elevations lakes from which water flows to sustain agriculture and cities. As climate and air quality in the region change, so do the watershed processes upon which these lakes depend. In order to understand the future of California’s ecology and natural resources, we need an integrated account of the environmental processes that underlie these aquatic systems. Synthesizing over three decades of research on the lakes and watersheds of the Sierra Nevada, this book develops an integrated account of the hydrological and biogeochemical systems that sustain them. With a focus on Emerald Lake in Sequoia National Park, the book marshals long-term limnological and ecological data to provide a detailed and synthetic account, while also highlighting the vulnerability of Sierra lakes to changes in climate and atmospheric deposition. In so doing, it lays the scientific foundations for predicting and understanding how the lakes and watersheds will respond.
Download or read book Cryosphere and climate change in the arctic the antarctic and the tibetan plateau written by Minghu Ding and published by Frontiers Media SA. This book was released on 2023-05-04 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Validating Reconstruction of Snow Water Equivalent in California s Sierra Nevada Using Measurements from the NASAAirborne Snow Observatory written by Robert E. Davis and published by . This book was released on 2016 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurately estimating basin‐wide snow water equivalent (SWE) is the most important unsolved problem in mountain hydrology. Models that rely on remotely sensed inputs are especially needed in ranges with few surface measurements. The NASA Airborne Snow Observatory (ASO) provides estimates of SWE at 50 m spatial resolution in several basins across the Western U.S. during the melt season. Primarily, water managers use this information to forecast snowmelt runoff into reservoirs; another impactful use of ASO measurements lies in validating and improving satellite‐based snow estimates or models that can scale to whole mountain ranges, even those without ground‐based measurements. We compare ASO measurements from 2013 to 2015 to four methods that estimate spatially distributed SWE: two versions of a SWE reconstruction method, spatial interpolation from snow pillows and courses, and NOAA's Snow Data Assimilation System (SNODAS). SWE reconstruction downscales energy forcings to compute potential melt, then multiplies those values by satellite‐derived estimates of fractional snow‐covered area to calculate snowmelt. The snowpack is then built in reverse from the date the snow is observed to disappear. The two SWE reconstruction models tested include one that employs an energy balance calculation of snowmelt, and one that combines net radiation and degree‐day approaches to estimate melt. Our full energy balance model, without ground observations, performed slightly better than spatial interpolation from snow pillows, having no systematic bias and 26% mean absolute error when compared to SWE from ASO. Both reconstruction models and interpolation were more accurate than SNODAS.
Download or read book A Point Energy and Mass Balance Model of a Snow Cover written by Eric A. Anderson and published by . This book was released on 1976 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimating the Spatial and Temporal Distribution of Snow in Mountainous Terrain written by Keith Newton Musselman and published by . This book was released on 2012 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: In-situ measurements and numerical models were used to quantify and improve understanding of the processes governing snowpack dynamics in mountainous terrain. Three studies were conducted in Sequoia National Park in the southern Sierra Nevada, California. The first two studies evaluated and simulated the variability of observed melt rates at the point-scale in a mixed conifer forest. The third study evaluated the accuracy of a distributed snow model run over 1800 km2; a 3600 m elevation gradient that includes ecosystems ranging from semi-arid grasslands to massive sequoia stands to alpine tundra. In the first study, a network of 24 automated snow depth sensors and repeated monthly snow density surveys in a conifer forest were used to measure snow ablation rates for three years. A model was developed to estimate the direct beam solar radiation beneath the forest canopy from upward-looking hemispherical photos and above-canopy measurements. Sub-canopy solar beam irradiance and the bulk canopy metric sky view factor explained the most (58% and 87%, respectively) of the observed ablation rates in years with the least and most cloud cover, respectively; no single metric could explain> 41% of the melt rate variability for all years. In the second study, the time-varying photo-derived direct beam canopy transmissivity and the sky view factor canopy parameter were incorporated into a one-dimensional physically based snowmelt model. Compared to a bulk parameterization of canopy radiative transfer, when the model was modified to accept the time-varying canopy transmissivity, errors in the simulated snow disappearance date were reduced by one week and errors in the timing of soil water fluxes were reduced by 11 days, on average. In the third study, a distributed land surface model was used to simulate snow depth and SWE dynamics for three years. The model was evaluated against data from regional automated SWE measurement stations, repeated catchment-scale depth and density surveys, and airborne LiDAR snow depth data. In general, the model accurately simulated the seasonal maximum snow depth and SWE at lower and middle elevation forested areas. The model tended to overestimate SWE at upper elevations where no precipitation measurements were available. The SWE errors could largely be explained (R2/super” 0.80, p0.01) by distance of the SWE measurement from the nearest precipitation gauge. The results suggest that precipitation uncertainty is a critical limitation on snow model accuracy. Finally, an analysis of seasonal and inter-annual snowmelt patterns highlighted distinct melt differences between lower, middle, and upper elevations. Snowmelt was generally most frequent (70% - 95% of the snow-covered season) at the lower elevations where snow cover was ephemeral and seasonal mean melt rates computed on days when melt was simulated were generally low (3 mm daysuper-1). At upper elevations, melt occurred during less than 65% of the snow-covered period, it occurred later in the season, and mean melt rates were the highest of the region ( 6 mm daysuper-1/super). Middle elevations remained continuously snow covered throughout the winter and early spring, were prone to frequent but intermittent melt, and provided the most sustained period of seasonal mean snowmelt (~ 5 mm day
Download or read book Advanced Concepts and Techniques in the Study of Snow and Ice Resources written by H. S. Santeford and published by National Academies. This book was released on 1974 with total page 810 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantifying and Modeling Subgrid Scale Snow Depth Variability in Forested Areas Throughout Multiple Climates in the Western United States written by William Ryan Currier and published by . This book was released on 2019 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mountain snowpack provides natural storage of freshwater. This natural storage far exceeds the extent of manmade reservoirs. Furthermore, watersheds throughout the western United States can be predominantly covered in forests. Forests decrease atmospheric winds, alter the amount of incoming radiation, and intercept snowfall, leading to significant variation in snow depth throughout the forest. Snow depth variability influences the magnitude, timing, and temperature of streamflow. Additionally, snow depth variability can drive ecological processes and affect the energy exchanged between the land and the atmosphere. To quantify snow depth variability in forests, spatially continuous, high-resolution (1-3 m) observations are needed at watershed extents. Chapter I of this dissertation evaluates the ability for airborne lidar to derive snow depth underneath the canopy by comparing airborne lidar to terrestrial lidar and snow depth probe transects from NASA's 2017 SnowEx campaign. Differences between gridded airborne lidar and ground-based observations did not increase underneath the canopy. Airborne lidar observations were therefore used in Chapter 2 to examine forest snow depth variability in four different snow climates throughout the western United States. In the Jemez Mountains, NM and in Tuolumne, CA, snow depth differences between north and south-facing sides of the canopy were statistically significant and greater than or equal to the difference between areas underneath the canopy and in the open. To account for this variability, a tiling parameterization, was incorporated into the Distributed Hydrologic and Soil Vegetation Model (DHSVM). The tiling parameterization explicitly simulates radiation differences within the forest and accounts for horizontal forest structure by using classifications from high-resolution vegetation maps. The tile parameterization therefore tested the impact of explicit forest representation on simulated snow water equivalent (SWE) and streamflow compared to the original implicit representation in three watersheds throughout the western United States. In Jemez, NM, where forests were relatively sparse and trees were 10.2 m tall, the tile model's grid-cell average snow disappearance date (SDD) was 12 days earlier and peak streamflow occurred 20-days earlier than the original model. In the Chiwawa, WA, where forests were dense and 17.2 m tall, SDD was 11 days later and late-season streamflow increased up to 11-13%. Despite statistically different snow depth distributions, forest edges had a relatively small effect on simulated streamflow (2-6%). However, grid cell average ablation rates and streamflow were primarily impacted by tiled grid cells, which only contained exposed and forested areas. The contrasting responses between the Jemez and Chiwawa were primarily controlled by the grid cells average fractional forest cover and the forest's radiation attenuation, which is a function of tree height and the sun's elevation angle. Ultimately, DHSVM's tile parameterization is a tool that more realistically represents forest radiation and while forest-edge contributions were relatively small within the existing forest structure, going forward, forest managers could use the tile parameterization to better understand how changes in the forest structure (e.g. maximizing forest shading) affect streamflow.
Download or read book Application of a Point Energy Balance Model of a Snow Cover written by Lisa Von der Heydt and published by . This book was released on 1992 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatial Time series Analysis of Satellite Derived Snow Water Equivalence written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As the need to understand climate induced changes increases, so too does the need to understand the long-term spatial-temporal characteristics of snow cover and snow water equivalence (SWE). Snow cover and SWE are useful indicators of climate change. In this research, we combine methods from spatial statistics, geographic information systems (GIS), time-series analysis, ecosystems classification, cluster analysis, and remote sensing, to provide a unique perspective on the spatial-temporal interactions of SWE. We show that within the Canadian Prairies, extreme SWE are becoming more spatially constrained, and may cause some regions to be more prone to flooding. As well, we find that the temporal characteristics of SWE are not captured by current ecological management units, highlighting the need for Canadian ecological management units that consider winter conditions. We then address this need by developing methods designed to generate geographically distinct SWE regimes. These regimes are used to partition the landscape into winter-based management units, and compared with conventional summer based units. We find that regional variations in the ability of current ecological units to capture SWE characteristics exist, and suggest that SWE regimes generated as a result of this analysis should be used as guidelines for developing winter-based management units in conjunction with current ecological stratifications.
Download or read book Energy Balance and Ablation of Snow as Affected by Manure Application written by Cezar Engjell Kongoli and published by . This book was released on 2000 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatial Time series Analysis of Satellite Derived Snow Water Equivalence written by Carson John Quentry Farmer and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As the need to understand climate induced changes increases, so too does the need to understand the long-term spatial-temporal characteristics of snow cover and snow water equivalence (SWE). Snow cover and SWE are useful indicators of climate change. In this research, we combine methods from spatial statistics, geographic information systems (GIS), time-series analysis, ecosystems classification, cluster analysis, and remote sensing, to provide a unique perspective on the spatial-temporal interactions of SWE. We show that within the Canadian Prairies, extreme SWE are becoming more spatially constrained, and may cause some regions to be more prone to flooding. As well, we find that the temporal characteristics of SWE are not captured by current ecological management units, highlighting the need for Canadian ecological management units that consider winter conditions. We then address this need by developing methods designed to generate geographically distinct SWE regimes. These regimes are used to partition the landscape into winter-based management units, and compared with conventional summerbased units. We find that regional variations in the ability of current ecological units to capture SWE characteristics exist, and suggest that SWE regimes generated as a result of this analysis should be used as guidelines for developing winter-based management units in conjunction with current ecological stratifications.
Download or read book Large Scale Effects of Seasonal Snow Cover written by International Commission of Snow and Ice and published by Wallingford [England] : International Association of Hydrological Sciences. This book was released on 1987 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatially Averaged Physics of the Snowmelt Process written by Federico Ernesto Horne and published by . This book was released on 1993 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Balance and Runoff from a Subarctic Snowpack written by A. J. Price and published by . This book was released on 1976 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Part I a physically based model was used to predict daily snowmelt on 2000 m sq plots in the Subarctic. The plots had a range of aspects and inclinations in boreal forest and on the tundra. The energy balance, computed for each of the plots, was compensated for differences in radiative and turbulent energy fluxes caused by varied slope geometry and vegetative cover. The turbulent energy fluxes were also corrected for the effects of the stable stratification of the air over the snow surface. The predictions of the model were compared with daily melts derived from runoff measured on the snowmelt plots. The results show that the method is a good predictor of daily amounts of snowmelt, although some uncertainties are introduced by changes in the snow surface during the melt period. In Part II, a physically based model of the movement of water through snowpacks was used to calculate hydrographs generated by diurnal waves of snowmelt on the tundra and in the boreal forest of subarctic Labrador. The model was tested against measured hydrographs from hillside plots that sampled a range of aspect, gradient, length, vegetative cover, and snow depth and density. The model yielded good results, particularly in the prediction of peak runoff rates, though there was a slight overestimate of the lag time. A comparison of predictions against field measurements indicated that, given the ranges over which each of the controls is likely to vary, the two most critical factors controlling the hydrograph are the snow depth and the melt rate, which must be predicted precisely for short intervals of time. Permeability of the snowpack is another important control, but it can be estimated closely from published values. (Author).
