A first attempt to model an Artificial Ice Reservoir (Ice Stupa) using a simple energy balance approach

2020 ◽  
Author(s):  
Suryanarayanan Balasubramanian ◽  
Martin Hoelzle ◽  
Michael Lehning ◽  
Sonam Wangchuk ◽  
Johannes Oerlemans ◽  
...  
Keyword(s):  
Water Mass ◽  
Meteorological Data ◽  
Physical Processes ◽  
Discharge Data ◽  
One Dimensional ◽  
Vapour Diffusion ◽  
Alternate Model ◽  
Energy Balance Approach ◽  
Fresh Water Resource ◽  
Model Scenarios

<div> <div> <p>Artificial Ice Reservoirs (AIRs, also called icestupas) have been successful in storing water during winter and releasing the water during spring and summer. Therefore, they can be seen as a vital fresh water resource for irrigation in dry environments. Many different forms of AIRs do exist and not many studies have tried to model theses ice structures.<br>We will present simulations of the most important physical processes that causes the formation and melt of AIRs using one dimensional equations governing the heat transfer, vapour diffusion and water transport of a phase changing water mass. For validation, an AIR was constructed in Schwarzsee region in the Canton of Fribourg, Switzerland. Meteorological data in conjunction with fountain discharge data was measured. According to the model, the Schwarzsee AIR was able to store and discharge 850 litres or  3.7 percent of all the water sprayed over a duration of 41 days. Alternate model scenarios will also be presented to show how this freezing efficiency can be increased.</p> </div> </div>

scholarly journals Estimation of equivalent permeability of snowpack using a snowmelt lysimeter at Patsio, northwest Himalaya

2010 ◽  
Vol 51 (54) ◽  
pp. 195-199 ◽  
Author(s):  
Prem Datt ◽  
P.K. Srivastava ◽  
G.K. Sood ◽  
P.K. Satyawali
Keyword(s):  
Wave Speed ◽  
Meteorological Data ◽  
High Capacity ◽  
Physical And Mechanical Properties ◽  
Research Station ◽  
Geometrical Shape ◽  
Discharge Data ◽  
Percolation Process ◽  
Equivalent Permeability ◽  
Energy Balance Approach

AbstractThe meltwater percolation process through the snowpack greatly influences its physical and mechanical properties. The percolation process is important for understanding the spring avalanche phenomenon as well as the meltwater runoff for basin hydrology studies. The permeability of individual snow layers depends on parameters such as porosity, pore connectivity and the geometrical shape of the pores. Snowpack equivalent permeability plays an important role in governing the transmission of meltwater through the different layers of the snowpack. In this paper, we present the design, fabrication and installation of a snowmelt lysimeter at Patsio field research station, Himachal Pradesh, India, and determine the snowpack equivalent permeability using lysimeter discharge data. The snowmelt lysimeter, having a collector area of 6.25 m2and a high-capacity snowmelt measuring tipping bucket, was installed on flat ground near the observatory with a data acquisition system. Snowmelt discharge measurements were made for two melt seasons, 2006/07 and 2007/08. Snow and meteorological data were collected at 15 min intervals using a semi-automatic weather station. The hourly surface snowmelt was estimated using an energy-balance approach. The maximum daily discharge was >2 mm w.e.h−1for most of the observation period. The daily mean wave speed of the meltwater front varied from 109 to 285 mm h−1for a daily mean discharge range of 0.6–1.8 mm w.e.h−1, while wave speeds for a particular melt flux of 2 mm w.e.h−1varied between 113 and 486 mm h−1. The pore-size distribution index was estimated using the power-fit relation between wave speed and discharge. The equivalent permeability of the snowpack was found to vary between 3.4 × 10−8and 9.9 × 10−12m2.

scholarly journals The Application of Box–Cox Transformation to Determine the Standardised Precipitation Index (SPI), the Standardised Discharge Index (SDI) and to Identify Drought Events: Case Study in Eastern Kujawy (Central Poland)

2014 ◽  
Vol 22 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Arkadiusz Bartczak ◽  
Ryszard Glazik ◽  
Sebastian Tyszkowski
Keyword(s):  
Normal Distribution ◽  
Meteorological Data ◽  
Precipitation Index ◽  
Low Flow ◽  
Monthly Precipitation ◽  
Discharge Data ◽  
Central Poland ◽  
Winter Half ◽  
Bartlett’S Test ◽  
Standardised Precipitation Index

Abstract The article presents the results of research into the transformation of series of hydro-meteorological data for determining dry periods with the Standardised Precipitation Index (SPI) and the Standardised Discharge Index (SDI). Time series from eight precipitation stations and five series of river discharge data in Eastern Kujawy (central Poland) were analysed for 1951–2010. The frequency distribution of the series for their convergence with the normal distribution was tested with the Shapiro–Wilk test and homogeneity with the Bartlett's test. The transformation of the series was done with the Box–Cox technique, which made it possible to homogenise the series in terms of variance. In Poland, the technique has never been used to determine the SPI. After the transformation the distributions of virtually all series complied with the normal distribution and were homogeneous. Moreover, a statistically significant correlation between the δ transformation parameter and the skewness of the series of monthly precipitation was observed. It was similar for the series of mean monthly discharges in the winter half-year and the hydrological year. The analysis indicates an alternate occurrence of dry and wet periods both in case of precipitation and run-offs. Drought periods coincided with low flow periods. Thus, the fluctuations tend to affect the development of agriculture more than long-term ones.

Effects on electrostatic fields excited by radio-frequency waves in a bounded plasma due to the ponderomotive force

1992 ◽  
Vol 47 (2) ◽  
pp. 271-279
Author(s):  
C. R. Gutiérrez-Tapia
Keyword(s):  
Radio Frequency ◽  
Driving Forces ◽  
Ponderomotive Force ◽  
Plasma Layer ◽  
Physical Processes ◽  
One Dimensional ◽  
Electrostatic Fields ◽  
Bounded Plasma ◽  
Linearly Polarized ◽  
Radio Frequency Waves

A one-dimensional model explaining the mechanism of excitation of electrostatic fields by linearly polarized radio-frequency waves in a plasma layer is presented. It is shown that the ponderomotive and driving forces influence this process strongly; however, these forces act at different times when a wave front passes through the plasma. We consider a semi-infinite plasma, and a plasma layer with and without current. It is observed that near to the plasma boundaries, where the electric field is large, there arise amplitude field oscillations, which are slowly exponentially damped in space. It is shown that the physical processes arising near the boundary x = L are similar to those at the boundary x = 0. It is seen that the current in the plasma block excitation at the boundary x = L.

Glaciers in the High Arctic and recent environmental change

1995 ◽  
Vol 352 (1699) ◽  
pp. 321-334 ◽  
Keyword(s):  
Mass Balance ◽  
Climate Warming ◽  
Meteorological Data ◽  
Ice Cores ◽  
High Arctic ◽  
Ice Age ◽  
Geological Evidence ◽  
Recent Climate ◽  
Severnaya Zemlya ◽  
Energy Balance Approach

High Arctic climate change over the last few hundred years includes the relatively cool Little Ice Age (LIA), followed by warming over the last hundred years or so. Meteorological data from the Eurasian High Arctic (Svalbard, Franz Josef Land, Severnaya Zemlya) and Canadian High Arctic islands are scarce before the mid-20th century, but longer records from Svalbard and Greenland show warming from about 1910-1920. Logs of Royal Navy ships in the Canadian Northwest Passage in the 1850s indicate temperatures cooler by 1-2.5 °C during the LIA. Other evidence of recent trends in High Arctic temperatures and precipitation is derived from ice cores, which show cooler temperatures (by 2-3 °C) for several hundred years before 1900, with high interdecadal variability. The proportion of melt layers in ice cores has also risen over the last 70-130 years, indicating warming. There is widespread geological evidence of glacier retreat in the High Arctic since about the turn of the century linked to the end of the LIA. An exception is the rapid advance of some surge-type ice masses. Mass balance measurements on ice caps in Arctic Canada, Svalbard and Severnaya Zemlya since 1950 show either negative or near-zero net balances, suggesting glacier response to recent climate warming. Glacier-climate links are modelled using an energy balance approach to predict glacier response to possible future climate warming, and cooler LIA temperatures. For Spitsbergen glaciers, a negative shift in mass balance of about 0.5 m a -1 is predicted for a 1 °C warming. A cooling of about 0.6 °C, or a 23% precipitation increase, would produce an approximately zero net mass balance. A ‘greenhouse-induced’ warming of 1 °C in the High Arctic is predicted to produce a global sea-level rise of 0.063 mm a -1 from ice cap melting.

Estimating wetness duration on maize ears from meteorological observations

1998 ◽  
Vol 78 (1) ◽  
pp. 149-154 ◽  
Author(s):  
P. S. Rao ◽  
T. J. Gillespie ◽  
A. W. Schaafsma
Keyword(s):  
Fungal Infections ◽  
Meteorological Data ◽  
Physical Models ◽  
Dew Point ◽  
Spatial And Temporal Variability ◽  
Threshold Models ◽  
Moderate Degree ◽  
Weather Station ◽  
Surface Wetness ◽  
Energy Balance Approach

The onset and cessation of surface wetness on maize ears were simulated with six models, using hourly meteorological data, to examine the linkage between wetness duration and possible forecasting of fungal infections that produce mycotoxins. Two threshold models (using relative humidity and dew point temperature), one regression model (using humidity and wind speed), and three physical models based on the energy balance approach, were compared. Also, spatial and temporal variability in wetness duration was measured and simulated at three sites located at distances up to 29 km from a central weather station. The estimated wetness values were compared with observations from cylindrical wetness sensors placed near ear level in maize canopies. The results relate to potential mycotoxin warning systems and indicate that threshold models can provide reasonable estimates of ear wetness duration in this region, that a comprehensive physical model can give superior estimates, and that wetness estimates made from a central weather station data can be extended to nearby crop fields with a moderate degree of confidence. Key words: epidemiology, mycotoxins, surface wetness models

scholarly journals A modification of the CABARET scheme for numerical simulation of one-dimensional detonation flows using a one-stage irreversible model of chemical kinetics

2017 ◽  
pp. 1-10
Author(s):  
А.В. Данилин ◽  
А.В. Соловьев ◽  
А.М. Зайцев
Keyword(s):  
Numerical Simulation ◽  
Chemical Kinetics ◽  
Order Of Approximation ◽  
Governing Equations ◽  
Physical Processes ◽  
Cabaret Scheme ◽  
One Dimensional ◽  
One Stage ◽  
The Right ◽  
Made In

Представлен алгоритм для численного моделирования задач одномерной детонации с использованием одностадийной необратимой модели химической кинетики. Дискретизация уравнений движения произведена согласно балансно-характеристической методике ``кабаре''. Аппроксимация источниковых членов выполнена без расщепления по физическим процессам с использованием неявного подхода с регулируемым порядком аппроксимации. Показано точное согласование параметров моделируемой детонации Чепмена--Жуге с аналитическим решением. Для неустойчивой детонации продемонстрирована зависимость результатов расчета от порядка аппроксимации правых частей. An algorithm for numerical simulation of one-dimensional detonation using a one-stage irreversible model of chemical kinetics is proposed. The discretization of the convective parts of governing equations is made in accordance with the balance-characteristic CABARET (Compact Accurately Boundary Adjusting-REsolution Technique) approach. The approximation of source terms is performed implicitly without splitting into physical processes with a regulated order of approximation. It is shown that the numerically obtained Chapman-Jouget detonation parameters are in exact agreement with the analytical solution. It is also shown that, in the case of unstable detonation, the numerical results are dependent on the order of approximation chosen for the right-hand sides of the governing equations.

Flood forecasting system for Brahmaputra river basin 

2021 ◽  
Author(s):  
Akash Kale ◽  
Vimal Mishra
Keyword(s):  
Land Surface ◽  
Agricultural Land ◽  
Flow Direction ◽  
Human Life ◽  
Meteorological Data ◽  
Brahmaputra River ◽  
Discharge Data ◽  
Near Surface ◽  
Vic Model ◽  
Major Floods

<p>Assam has always been India’s most flood prone state due to the presence of Brahmaputra river, which is very unstable in terms of its flow direction witnessing 12 major floods from 1950 to 2012. Flooding in the basin has affected around 2.75 million of people and 0.27 million hectares of agricultural land on an average causing catastrophic damage to human life and infrastructure. In this study, we analysed all the major floods across the Brahmaputra river in the past 70 years and established the dependency within discharge and atmospheric parameters. Variable Infiltration Capacity (VIC) model was set up to simulate the flow at two stations namely Yangcun, China and Bahadurabad, Bangladesh. We  used near surface meteorological data for driving land surface modelling systems from 1901 to 2016 as input parameters to the VIC model. To avoid the discontinuity of data after 2016, we used ECMWF reanalysis (ERA5) data for the period of 2016 to 2020. After obtaining the continuous simulated discharge for 120 years, we established the relationship between the observed and simulated discharge data for which the R-squared and Nash Sutcliffe coefficient values were 0.83 and 0.78 respectively. Comparing the simulated discharge with the observed extreme discharge at various locations on the river, we apply the model to address future flood situations.</p>

scholarly journals Lake ice growth and decay in central Alaska, USA: observations and computer simulations compared

2005 ◽  
Vol 40 ◽  
pp. 195-199 ◽  
Author(s):  
Martin O. Jeffries ◽  
Kim Morris ◽  
Claude R. Duguay
Keyword(s):  
Meteorological Data ◽  
Measured Data ◽  
Ice Thickness ◽  
Lake Ice ◽  
One Dimensional ◽  
Ice Growth ◽  
Unsteady Heat Conduction ◽  
Input Variables ◽  
Thickness Measurements ◽  
Ice Model

AbstractThe Canadian Lake Ice Model (CLIMo), a one-dimensional, thermodynamic model with unsteady heat conduction and penetrating solar radiation, is used to simulate ice growth and decay on shallow ponds in and near Fairbanks, central Alaska, USA. Simulations are compared with observations of ice thickness and composition (snow ice, congelation ice), freeze-up, break-up and duration. Simulations run using US National Weather Service meteorological data as input variables do not agree well with ice-thickness measurements. The simulations improve significantly when the model is run with more representative, locally measured data for air temperature and depth of snow on the ice. The causes of some discrepancies between simulations and observations are discussed and some suggestions for model improvements are made.

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