scholarly journals Crocus test results for snowpack modeling in two snow climates with respect to avalanche forecasting

1998 ◽  
Vol 26 ◽  
pp. 347-356 ◽  
Author(s):  
Laurent Mingo ◽  
D. M. Mcclung
Keyword(s):  
Snow Depth ◽  
Meteorological Data ◽  
Liquid Water Content ◽  
Temperature Profiles ◽  
Test Results ◽  
Density Profiles ◽  
Climate Zones ◽  
Avalanche Forecasting ◽  
Present Information ◽  
Snow Temperature

Overall results comparing field observations andCrocussimulations during the winters 1993–94 and 1994–95 in two different climate zones are presented. We present information on: snow depth, snow-temperature profiles, density profiles, liquid-water content profiles and grain metamorphism. Snow profiles illustrating the typical behavior of the model are presented and are shown to illustrate the sensitivity ofCrocusto different mountain climates. Heat-exchange simulation, together with qualitative analysis of meteorological data, give promising results for surface-hoar prediction.

scholarly journals Crocus test results for snowpack modeling in two snow climates with respect to avalanche forecasting

1998 ◽  
Vol 26 ◽  
pp. 347-356 ◽  
Author(s):  
Laurent Mingo ◽  
D. M. Mcclung
Keyword(s):  
Snow Depth ◽  
Meteorological Data ◽  
Liquid Water Content ◽  
Temperature Profiles ◽  
Test Results ◽  
Density Profiles ◽  
Climate Zones ◽  
Avalanche Forecasting ◽  
Present Information ◽  
Snow Temperature

Overall results comparing field observations and Crocus simulations during the winters 1993–94 and 1994–95 in two different climate zones are presented. We present information on: snow depth, snow-temperature profiles, density profiles, liquid-water content profiles and grain metamorphism. Snow profiles illustrating the typical behavior of the model are presented and are shown to illustrate the sensitivity of Crocus to different mountain climates. Heat-exchange simulation, together with qualitative analysis of meteorological data, give promising results for surface-hoar prediction.

scholarly journals An 18-yr long (1993–2011) snow and meteorological dataset from a mid-altitude mountain site (Col de Porte, France, 1325 m alt.) for driving and evaluating snowpack models

2012 ◽  
Vol 4 (1) ◽  
pp. 13-21 ◽  
Author(s):  
S. Morin ◽  
Y. Lejeune ◽  
B. Lesaffre ◽  
J.-M. Panel ◽  
D. Poncet ◽  
...  
Keyword(s):  
Snow Depth ◽  
Snow Water Equivalent ◽  
Meteorological Data ◽  
Model Performance ◽  
Short Wave ◽  
Wave Radiation ◽  
Density Profiles ◽  
The Public ◽  
Snow Water ◽  
Snowpack Properties

Abstract. A quality-controlled snow and meteorological dataset spanning the period 1 August 1993–31 July 2011 is presented, originating from the experimental station Col de Porte (1325 m altitude, Chartreuse range, France). Emphasis is placed on meteorological data relevant to the observation and modelling of the seasonal snowpack. In-situ driving data, at the hourly resolution, consist of measurements of air temperature, relative humidity, windspeed, incoming short-wave and long-wave radiation, precipitation rate partitioned between snow- and rainfall, with a focus on the snow-dominated season. Meteorological data for the three summer months (generally from 10 June to 20 September), when the continuity of the field record is not warranted, are taken from a local meteorological reanalysis (SAFRAN), in order to provide a continuous and consistent gap-free record. Data relevant to snowpack properties are provided at the daily (snow depth, snow water equivalent, runoff and albedo) and hourly (snow depth, albedo, runoff, surface temperature, soil temperature) time resolution. Internal snowpack information is provided from weekly manual snowpit observations (mostly consisting in penetration resistance, snow type, snow temperature and density profiles) and from a hourly record of temperature and height of vertically free ''settling'' disks. This dataset has been partially used in the past to assist in developing snowpack models and is presented here comprehensively for the purpose of multi-year model performance assessment. The data is placed on the PANGAEA repository (http://dx.doi.org/10.1594/PANGAEA.774249) as well as on the public ftp server ftp://ftp-cnrm.meteo.fr/pub-cencdp/.

scholarly journals Observaciones del manto de nieve durante una circunnavegación del casquete de hielo de Groenlandia (primavera de 2014)

2016 ◽  
Vol 42 (2) ◽  
pp. 369 ◽  
Author(s):  
J. I. López Moreno ◽  
M. Olivera-Marañón ◽  
J. Zabalza ◽  
R. H. De Larramendi
Keyword(s):  
Bulk Density ◽  
Snow Depth ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Atmospheric Temperature ◽  
Snow Accumulation ◽  
Dense Layer ◽  
Density Profiles ◽  
Highly Correlated ◽  
Snow Temperature

We report the characteristics of the Greenland ice sheet snowpack, based on data collected during the first wind-propelled circumnavigation of the ice sheet, undertaken in spring 2014. The dataset included snow depth measurements made in 100 m2 plots, and data on the snow bulk density and snowpack temperature at 1 m depth at 25 sites distributed along the 4301 km route traveled during the 49 days of the circumnavigation. In addition, eight snow pits of 1 m depth were dug to measure the snow temperature and density at 10 cm intervals in the upper layer of the snowpack. All this information may help to better understand snow characteristics on this remote area, and provide data to validate and calibrate atmospheric and cryospheric models.Snow depths exceeding 4 m were measured in the snow accumulation area, but in many cases the presence of an ice layer prevented penetration of the snow probe below 70 cm depth. This ice layer may be associated with the melting event that occurred in July 2012, and affected 98% of the ice sheet. Beyond the main snow accumulation zone, very constant snow depth values of approximately 1.5 m were measured. The snow temperature at 1 m depth generally ranged from –20°C to –10°C, and was highly correlated with the average atmospheric temperature during the 15 days prior to the snow temperature measurements. The snow bulk density was relatively homogeneous at the majority of sampling sites, ranging from 320 to 390 kg m–3. The snow temperature and density profiles measured in the snow pits indicated that the snowpack became progressively colder from the surface to 1 m depth. The temperature gradient measured in the snow pits was particularly steep (shallow) at the warmest (coldest) sampling sites. The snow density was characterized by denser snow at 60–80 cm depth, coinciding with the depth of the ice layer identified when depth was measured. A dense layer was also found close to the surface at the warmest snow pit sites, and it is likely that this corresponds to a more recent snow melt event.

scholarly journals A one-dimensional model of the evolution of snow-cover characteristics

1993 ◽  
Vol 18 ◽  
pp. 22-26 ◽  
Author(s):  
Takeshi Yamazaki ◽  
Junsei Kondo ◽  
Takashi Sakuraoka ◽  
Toru Nakamura
Keyword(s):  
Diurnal Variation ◽  
Snow Cover ◽  
Water Content ◽  
Liquid Water ◽  
Snow Depth ◽  
Meteorological Data ◽  
Dimensional Model ◽  
Snow Density ◽  
One Dimensional ◽  
Snow Temperature

A one-dimensional model has been developed to simulate the evolution of snow-cover characteristics using meteorological data. This model takes into account the heat balance at the snow surface and heat conduction in the snow cover as well as liquid water flow and densification. The basic variables of the model are snow temperature, liquid water content, snow density and the solid impurities density. With these four variables, the model can calculate albedo, thermal conductivity, liquid water flux, snow depth, water equivalent and the amount of runoff.Diurnal variation of profiles of snow temperature, water content and snow density, and meteorological elements were observed at Mount Zao Bodaira, Yamagata Prefecture, Japan. Simulated diurnal variation patterns of each component by the model were in good agreement with the observations. Moreover, the snow-cover characteristics were simulated for three 90-day periods with meteorological data and snow pit observations at Sapporo. It was found that the model was able to simulate long-period variations of albedo, snow depth, snow water equivalent and the snow density profile.

scholarly journals A one-dimensional model of the evolution of snow-cover characteristics

1993 ◽  
Vol 18 ◽  
pp. 22-26 ◽  
Author(s):  
Takeshi Yamazaki ◽  
Junsei Kondo ◽  
Takashi Sakuraoka ◽  
Toru Nakamura
Keyword(s):  
Diurnal Variation ◽  
Snow Cover ◽  
Water Content ◽  
Liquid Water ◽  
Snow Depth ◽  
Meteorological Data ◽  
Dimensional Model ◽  
Snow Density ◽  
One Dimensional ◽  
Snow Temperature

A one-dimensional model has been developed to simulate the evolution of snow-cover characteristics using meteorological data. This model takes into account the heat balance at the snow surface and heat conduction in the snow cover as well as liquid water flow and densification. The basic variables of the model are snow temperature, liquid water content, snow density and the solid impurities density. With these four variables, the model can calculate albedo, thermal conductivity, liquid water flux, snow depth, water equivalent and the amount of runoff. Diurnal variation of profiles of snow temperature, water content and snow density, and meteorological elements were observed at Mount Zao Bodaira, Yamagata Prefecture, Japan. Simulated diurnal variation patterns of each component by the model were in good agreement with the observations. Moreover, the snow-cover characteristics were simulated for three 90-day periods with meteorological data and snow pit observations at Sapporo. It was found that the model was able to simulate long-period variations of albedo, snow depth, snow water equivalent and the snow density profile.

scholarly journals A 18-yr long (1993–2011) snow and meteorological dataset from a mid-altitude mountain site (Col de Porte, France, 1325 m alt.) for driving and evaluating snowpack models

2012 ◽  
Vol 5 (1) ◽  
pp. 29-45 ◽  
Author(s):  
S. Morin ◽  
Y. Lejeune ◽  
B. Lesaffre ◽  
J.-M. Panel ◽  
D. Poncet ◽  
...  
Keyword(s):  
Snow Depth ◽  
Snow Water Equivalent ◽  
Meteorological Data ◽  
Model Performance ◽  
Short Wave ◽  
Wave Radiation ◽  
Density Profiles ◽  
The Public ◽  
Snow Water

Abstract. A quality-controlled snow and meteorological dataset spanning the period 1 August 1993–31 July 2011 is presented, originating from the experimental station Col de Porte (1325 m altitude, Chartreuse range, France). Emphasis is placed on meteorological data relevant to the observation and modelling of the seasonal snowpack. In-situ driving data, at the hourly resolution, consist in measurements of air temperature, relative humidity, wind speed, incoming short-wave and long-wave radiation, precipitation rate partitioned between snow- and rainfall, with a focus on the snow-dominated season. Meteorological data for the three summer months (generally from 10 June to 20 September), when the continuity of the field record is not warranted, are taken from a local meteorological reanalysis (SAFRAN), in order to provide a continuous and consistent gap-free record. Evaluation data are provided at the daily (snow depth, snow water equivalent, runoff and albedo) and hourly (snow depth, albedo, runoff, surface temperature, soil temperature) time resolution. Internal snowpack information are provided from weekly manual snowpit observations (mostly consisting in penetration resistance, snow type, snow temperature and density profiles) and from a hourly record of temperature and height of vertically free "settling" disks. This dataset has been partially used in the past to assist in developing snowpack model and is presented here comprehensively for the purpose of multi-year model performance assessment. The data is placed on the PANGAEA repository (http://doi.pangaea.de/10.1594/PANGAEA.774249) as well as on the public ftp server ftp://ftp-cnrm.meteo.fr/pub-cencdp/.

scholarly journals Seasonal influence of snow conditions on Dall’s sheep productivity in Wrangell-St Elias National Park and Preserve

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0244787
Author(s):  
Christopher L. Cosgrove ◽  
Jeff Wells ◽  
Anne W. Nolin ◽  
Judy Putera ◽  
Laura R. Prugh
Keyword(s):  
Snow Depth ◽  
National Park ◽  
Meteorological Data ◽  
Multiple Regression Model ◽  
Snow Accumulation ◽  
Population Declines ◽  
Climate Conditions ◽  
Remote Cameras ◽  
Snow Conditions ◽  
Dall’S Sheep

Dall’s sheep (Ovis dalli dalli) are endemic to alpine areas of sub-Arctic and Arctic northwest America and are an ungulate species of high economic and cultural importance. Populations have historically experienced large fluctuations in size, and studies have linked population declines to decreased productivity as a consequence of late-spring snow cover. However, it is not known how the seasonality of snow accumulation and characteristics such as depth and density may affect Dall’s sheep productivity. We examined relationships between snow and climate conditions and summer lamb production in Wrangell-St Elias National Park and Preserve, Alaska over a 37-year study period. To produce covariates pertaining to the quality of the snowpack, a spatially-explicit snow evolution model was forced with meteorological data from a gridded climate re-analysis from 1980 to 2017 and calibrated with ground-based snow surveys and validated by snow depth data from remote cameras. The best calibrated model produced an RMSE of 0.08 m (bias 0.06 m) for snow depth compared to the remote camera data. Observed lamb-to-ewe ratios from 19 summers of survey data were regressed against seasonally aggregated modelled snow and climate properties from the preceding snow season. We found that a multiple regression model of fall snow depth and fall air temperature explained 41% of the variance in lamb-to-ewe ratios (R2 = .41, F(2,38) = 14.89, p<0.001), with decreased lamb production following deep snow conditions and colder fall temperatures. Our results suggest the early establishment and persistence of challenging snow conditions is more important than snow conditions immediately prior to and during lambing. These findings may help wildlife managers to better anticipate Dall’s sheep recruitment dynamics.

Combustion Effects of Coal Liquid and Other Synthetic Fuels in Gas Turbine Combustors: Part I — Fuels Used and Subscale Combustion Results

1980 ◽  
Author(s):  
P. P. Singh ◽  
A. Cohn ◽  
P. W. Pillsbury ◽  
G. W. Bauserman ◽  
P. R. Mulik ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Companion Paper ◽  
Liquid Fuels ◽  
Temperature Profiles ◽  
Test Results ◽  
Synthetic Fuels ◽  
Unburned Hydrocarbons ◽  
Combustion Tests ◽  
Percent Nitrogen

Combustion tests on over twelve types of coal derived liquid fuels from the EDS, H-coal, SRC-I and SRC-II processes and three shale oil fuels have been conducted in gas turbine type combustors. Emission measurements were made of Nox, smoke, CO, and unburned hydrocarbons. Combustor wall temperature profiles were measured. The results are correlated with the fuel properties-percent nitrogen, hydrogen and aromaticity. This part of the paper discusses the fuels used in subscale combustion tests along with the test results. A companion paper (Part II) describes the results of full-scale combustor tests and a long term corrosion/deposition test.

Short-Term Snow Melt and Ablation Derived from Heat- and Mass-Balance Measurements

1973 ◽  
Vol 12 (65) ◽  
pp. 275-289 ◽  
Author(s):  
Paul M. B. Föhn
Keyword(s):  
Mass Balance ◽  
Water Content ◽  
Free Water ◽  
Liquid Water Content ◽  
Snow Melt ◽  
Snow Pack ◽  
Density Profiles ◽  
Run Off ◽  
Free Water Content ◽  
Meteorological Observations

AbstractThe daily snow melt calculated from meteorological observations is compared with detailed mass-balance measurements taking into account internal changes in density and free water content in the surface layers of a glacier snow-pack. The energy balance is calculated from measurements obtained by a meteorological station at the experimental site. In addition to the standard ablation measurements the run-off from the melting snow-pack was obtained for a few days. The snow-density profiles were measured with a portable gamma-transmission probe and the liquid-water content of snow was determined by a calorimetric method.Agreement between the melt calculated by the heat-balance method and the mass changes observed in the mass-balance measurements is fair for daily periods. It appears that about 20% of the daily snow melt takes place internally as a result of penetration of solar radiation.

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