scholarly journals Centreline and cross-glacier air temperature variability on an Alpine glacier: assessing temperature distribution methods and their influence on melt model calculations

2017 ◽  
Vol 63 (242) ◽  
pp. 973-988 ◽  
Author(s):  
THOMAS E. SHAW ◽  
BEN W. BROCK ◽  
ÁLVARO AYALA ◽  
NICK RUTTER ◽  
FRANCESCA PELLICCIOTTI
Keyword(s):  
Temperature Distribution ◽  
Air Temperature ◽  
Temporal Distribution ◽  
Temperature Variability ◽  
Lapse Rate ◽  
Balance Model ◽  
Model Parameters ◽  
Ambient Conditions ◽  
Distribution Models ◽  
Model Calculations

ABSTRACTThe spatio-temporal distribution of air temperature over mountain glaciers can demonstrate complex patterns, yet it is often represented simplistically using linear vertical temperature gradients (VTGs) extrapolated from off-glacier locations. We analyse a network of centreline and lateral air temperature observations at Tsanteleina Glacier, Italy, during summer 2015. On average, VTGs are steep (<−0.0065 °C m−1), but they are shallow under warm ambient conditions when the correlation between air temperature and elevation becomes weaker. Published along-flowline temperature distribution methods explain centreline observations well, including warming on the lower glacier tongue, but cannot estimate lateral temperature variability. Application of temperature distribution methods improves simulation of melt rates (RMSE) in an energy-balance model by up to 36% compared to the environmental lapse rate extrapolated from an off-glacier station. However, results suggest that model parameters are not easily transferable to glaciers with a small fetch without recalibration. Such methods have potential to improve estimates of temperature across a glacier, but their parameter transferability should be further linked to the glacier and atmospheric characteristics. Furthermore, ‘cold spots’, which can be >2°C cooler than expected for their elevation, whose occurrence is not predicted by the temperature distribution models, are identified at one-quarter of the measurement sites.

scholarly journals Air temperature variability over three glaciers in the Ortles–Cevedale (Italian Alps): effects of glacier fragmentation, comparison of calculation methods, and impacts on mass balance modeling

2015 ◽  
Vol 9 (3) ◽  
pp. 1129-1146 ◽  
Author(s):  
L. Carturan ◽  
F. Cazorzi ◽  
F. De Blasi ◽  
G. Dalla Fontana
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Temperature Variability ◽  
Cooling Effect ◽  
Balance Model ◽  
Spatial And Temporal Variability ◽  
Glacier Mass Balance ◽  
Ambient Conditions ◽  
Data Set ◽  
Mass Balance Models

Abstract. Glacier mass balance models rely on accurate spatial calculation of input data, in particular air temperature. Lower temperatures (the so-called glacier cooling effect) and lower temperature variability (the so-called glacier damping effect) generally occur over glaciers compared to ambient conditions. These effects, which depend on the geometric characteristics of glaciers and display a high spatial and temporal variability, have been mostly investigated on medium to large glaciers so far, while observations on smaller ice bodies (< 0.5 km2) are scarce. Using a data set from eight on-glacier and four off-glacier weather stations, collected in the summers of 2010 and 2011, we analyzed the air temperature variability and wind regime over three different glaciers in the Ortles–Cevedale. The magnitude of the cooling effect and the occurrence of katabatic boundary layer (KBL) processes showed remarkable differences among the three ice bodies, suggesting the likely existence of important reinforcing mechanisms during glacier decay and fragmentation. The methods proposed by Greuell and Böhm (1998) and Shea and Moore (2010) for calculating on-glacier temperature from off-glacier data did not fully reproduce our observations. Among them, the more physically based procedure of Greuell and Böhm (1998) provided the best overall results where the KBL prevails, but it was not effective elsewhere (i.e., on smaller ice bodies and close to the glacier margins). The accuracy of air temperature estimations strongly impacted the results from a mass balance model which was applied to the three investigated glaciers. Most importantly, even small temperature deviations caused distortions in parameter calibration, thus compromising the model generalizability.

scholarly journals Air temperature variability over three glaciers in the Ortles-Cevedale (Italian Alps): effects of glacier disintegration, intercomparison of calculation methods, and impacts on mass balance modeling

2014 ◽  
Vol 8 (6) ◽  
pp. 6147-6192 ◽  
Author(s):  
L. Carturan ◽  
F. Cazorzi ◽  
F. De Blasi ◽  
G. Dalla Fontana
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Temperature Variability ◽  
Cooling Effect ◽  
Balance Model ◽  
Spatial And Temporal Variability ◽  
Glacier Mass Balance ◽  
Ambient Conditions ◽  
Mass Balance Models ◽  
Physically Based

Abstract. Glacier mass balance models rely on accurate spatial calculation of input data, in particular air temperature. Lower temperatures (the so-called glacier cooling effect), and lower temperature variability (the so-called glacier damping effect) generally occur over glaciers, compared to ambient conditions. These effects, which depend on the geometric characteristics of glaciers and display a high spatial and temporal variability, have been mostly investigated on medium- to large-size glaciers so far, while observations on smaller ice bodies are scarce. Using a dataset from 8 on-glacier and 4 off-glacier weather stations, collected in summer 2010 and 2011, we analyzed the air temperature variability and wind regime over three different glaciers in the Ortles-Cevedale. The magnitude of the cooling effect and the occurrence of katabatic boundary layer (KBL) processes showed remarkable differences among the three ice bodies, suggesting the likely existence of important reinforcing mechanisms during glacier decay and disintegration. None of the methods proposed in the literature for calculating on-glacier temperature from off-glacier data fully reproduced our observations. Among them, the more physically-based procedure of Greuell and Böhm (1998) provided the best overall results where the KBL prevail, but it was not effective elsewhere (i.e. on smaller ice bodies and close to the glacier margins). The accuracy of air temperature estimations strongly impacted the results from a mass balance model which was applied to the three investigated glaciers. Most importantly, even small temperature deviations caused distortions in parameter calibration, thus compromising the model generalizability.

scholarly journals Air temperature distribution and energy-balance modelling of a debris-covered glacier

2016 ◽  
Vol 62 (231) ◽  
pp. 185-198 ◽  
Author(s):  
THOMAS E. SHAW ◽  
BEN W. BROCK ◽  
CATRIONA L. FYFFE ◽  
FRANCESCA PELLICCIOTTI ◽  
NICK RUTTER ◽  
...  
Keyword(s):  
Energy Balance ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
High Elevation ◽  
Lapse Rate ◽  
Balance Model ◽  
Linear Temperature ◽  
Near Surface ◽  
Ice Melt ◽  
Debris Cover

ABSTRACTNear-surface air temperature is an important determinant of the surface energy balance of glaciers and is often represented by a constant linear temperature gradients (TGs) in models. Spatio-temporal variability in 2 m air temperature was measured across the debris-covered Miage Glacier, Italy, over an 89 d period during the 2014 ablation season using a network of 19 stations. Air temperature was found to be strongly dependent upon elevation for most stations, even under varying meteorological conditions and at different times of day, and its spatial variability was well explained by a locally derived mean linear TG (MG–TG) of −0.0088°C m−1. However, local temperature depressions occurred over areas of very thin or patchy debris cover. The MG–TG, together with other air TGs, extrapolated from both on- and off-glacier sites, were applied in a distributed energy-balance model. Compared with piecewise air temperature extrapolation from all on-glacier stations, modelled ablation, using the MG–TG, increased by <1%, increasing to >4% using the environmental ‘lapse rate’. Ice melt under thick debris was relatively insensitive to air temperature, while the effects of different temperature extrapolation methods were strongest at high elevation sites of thin and patchy debris cover.

scholarly journals Air temperature distribution and energy-balance modelling of a debris-covered glacier

2016 ◽  
pp. 1-14 ◽  
Author(s):  
THOMAS E. SHAW ◽  
BEN W. BROCK ◽  
CATRIONA L. FYFFE ◽  
FRANCESCA PELLICCIOTTI ◽  
NICK RUTTER ◽  
...  
Keyword(s):  
Energy Balance ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
High Elevation ◽  
Lapse Rate ◽  
Balance Model ◽  
Linear Temperature ◽  
Near Surface ◽  
Ice Melt ◽  
Debris Cover

ABSTRACTNear-surface air temperature is an important determinant of the surface energy balance of glaciers and is often represented by a constant linear temperature gradients (TGs) in models. Spatio-temporal variability in 2 m air temperature was measured across the debris-covered Miage Glacier, Italy, over an 89 d period during the 2014 ablation season using a network of 19 stations. Air temperature was found to be strongly dependent upon elevation for most stations, even under varying meteorological conditions and at different times of day, and its spatial variability was well explained by a locally derived mean linear TG (MG–TG) of −0.0088°C m−1. However, local temperature depressions occurred over areas of very thin or patchy debris cover. The MG–TG, together with other air TGs, extrapolated from both on- and off-glacier sites, were applied in a distributed energy-balance model. Compared with piecewise air temperature extrapolation from all on-glacier stations, modelled ablation, using the MG–TG, increased by &lt;1%, increasing to &gt;4% using the environmental ‘lapse rate’. Ice melt under thick debris was relatively insensitive to air temperature, while the effects of different temperature extrapolation methods were strongest at high elevation sites of thin and patchy debris cover.

scholarly journals The variability of radiative balance elements and air temperature over the Asian region of Russia

2012 ◽  
Vol 9 (3) ◽  
pp. 1113-1123 ◽  
Author(s):  
E. V. Kharyutkina ◽  
I. I. Ippolitov ◽  
S. V. Loginov
Keyword(s):  
Global Warming ◽  
Air Temperature ◽  
Heat Balance ◽  
Cloud Cover ◽  
Temporal Distribution ◽  
Reanalysis Data ◽  
Temperature Variability ◽  
Shortwave Radiation ◽  
Earth Atmosphere ◽  
Radiative Balance

Abstract. The variability of spatial-temporal distribution of temperature and heat balance elements is investigated for the Asian territory of Russia (45–80° N, 60–180° E) using JRA-25, NCEP/DOE AMIP-II reanalysis data and observational data for the period of global warming 1979–2008. It is shown that temperature trend over the territory is 1.4 °C for the period under study according to reanalysis data. Since the beginning of 90s of 20th century the increase of back earth-atmosphere shortwave radiation is observed. Such tendency is in conformity with the cloud cover distribution and downward shortwave radiation at the surface. Regression model describing temperature variability with variability of heat balance elements was presented. We conclude that possible applications for the model include the convenient estimate of temperature variability according to reanalysis data.

scholarly journals Response of the Energy Balance on the Margin of the Greenland Ice Sheet to Temperature Changes

1990 ◽  
Vol 36 (123) ◽  
pp. 217-221 ◽  
Author(s):  
Roger J. Braithwaite ◽  
Ole B. Olesen
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Air Temperature ◽  
Sensible Heat Flux ◽  
Ice Sheet ◽  
Temperature Response ◽  
Greenland Ice Sheet ◽  
Energy Balance Model ◽  
Balance Model ◽  
Sensible Heat

AbstractDaily ice ablation on two outlet glaciers from the Greenland ice sheet, Nordbogletscher (1979–83) and Qamanârssûp sermia (1980–86), is related to air temperature by a linear regression equation. Analysis of this ablation-temperature equation with the help of a simple energy-balance model shows that sensible-heat flux has the greatest temperature response and accounts for about one-half of the temperature response of ablation. Net radiation accounts for about one-quarter of the temperature response of ablation, and latent-heat flux and errors account for the remainder. The temperature response of sensible-heat flux at QQamanârssûp sermia is greater than at Nordbogletscher mainly due to higher average wind speeds. The association of high winds with high temperatures during Föhn events further increases sensible-heat flux. The energy-balance model shows that ablation from a snow surface is only about half that from an ice surface at the same air temperature.

Investigating the effect of wearing glasses on the human eyes' temperature distribution in different ambient conditions

2021 ◽  
pp. 102971
Author(s):  
Kavan Zarei ◽  
Mansour Lahonian ◽  
Saman Aminian ◽  
Sasan Saedi ◽  
Mehdi Ashjaee
Keyword(s):  
Temperature Distribution ◽  
Ambient Conditions ◽  
Human Eyes

scholarly journals The Temperature of Halite Crystallization in the Badenian Saline Basins, in the Context of Paleoclimate Reconstruction of the Carpathian Area

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 831
Author(s):  
Anatoliy R. Galamay ◽  
Krzysztof Bukowski ◽  
Igor M. Zinczuk ◽  
Fanwei Meng
Keyword(s):  
Temperature Distribution ◽  
Air Temperature ◽  
Fluid Inclusions ◽  
Middle Miocene ◽  
Single Phase ◽  
Dead Sea ◽  
Paleoclimate Reconstruction ◽  
Near Surface ◽  
Carpathian Region ◽  
Primary Fluid

Currently, fluid inclusions in halite have been frequently studied for the purpose of paleoclimate reconstruction. For example, to determine the air temperature in the Middle Miocene (Badenian), we examine single-phase primary fluid inclusions of the bottom halites (chevron and full-faceted) and near-surface (cumulate) halites collected from the salt-bearing deposits of the Carpathian region. Our analyses showed that the temperatures of near-bottom brines varied in ranges from 19.5 to 22.0 °C and 24.0 to 26.0 °C, while the temperatures of the surface brines ranged from 34.0 to 36.0 °C. Based on these data, such as an earlier study of lithology and sedimentary structures of the Badenian rock salts, the crystallization of bottom halite developed in the basin from concentrated and cooled near-surface brines of about 30 m depth. Our results comply with the data on the temperature distribution in the modern Dead Sea.

scholarly journals Assessment of High Resolution Air Temperature Fields at Rocky Mountain National Park by Combining Scarce Point Measurements with Elevation and Remote Sensing Data

2020 ◽  
Vol 13 (1) ◽  
pp. 113
Author(s):  
Antonio-Juan Collados-Lara ◽  
Steven R. Fassnacht ◽  
Eulogio Pardo-Igúzquiza ◽  
David Pulido-Velazquez
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Air Temperature ◽  
Land Surface ◽  
National Park ◽  
Rocky Mountain ◽  
Rocky Mountain National Park ◽  
Temperature Fields ◽  
Lapse Rate ◽  
Validation Experiment

There is necessity of considering air temperature to simulate the hydrology and management within water resources systems. In many cases, a big issue is considering the scarcity of data due to poor accessibility and limited funds. This paper proposes a methodology to obtain high resolution air temperature fields by combining scarce point measurements with elevation data and land surface temperature (LST) data from remote sensing. The available station data (SNOTEL stations) are sparse at Rocky Mountain National Park, necessitating the inclusion of correlated and well-sampled variables to assess the spatial variability of air temperature. Different geostatistical approaches and weighted solutions thereof were employed to obtain air temperature fields. These estimates were compared with two relatively direct solutions, the LST (MODIS) and a lapse rate-based interpolation technique. The methodology was evaluated using data from different seasons. The performance of the techniques was assessed through a cross validation experiment. In both cases, the weighted kriging with external drift solution (considering LST and elevation) showed the best results, with a mean squared error of 3.7 and 3.6 °C2 for the application and validation, respectively.

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