scholarly journals Heat-Budget Measurements on the Quelccaya Ice Cap, Peruvian Andes

1978 ◽  
Vol 20 (82) ◽  
pp. 85-97 ◽  
Author(s):  
Stefan Hastenrath
Keyword(s):  
Heat Budget ◽  
Sunshine Duration ◽  
Field Work ◽  
Short Wave ◽  
Wave Radiation ◽  
Peruvian Andes ◽  
Major Mechanism ◽  
Ice Cap ◽  
Wide Range ◽  
Quelccaya Ice Cap

AbstractDuring the June-August 1976 Quelccaya ice cap expedition, global, SW↓, and net long-wave radiation, LW↑↓, were measured through several complete day-night cycles, and for a wide range of cloudiness conditions. Field work further included albedo measurements along representative transects across the ice cap and lysimeter-type estimates of ablation. Automatic stations recording wind, temperature and sunshine duration were also installed.Daily totals of SW↓ and LW↑↓ representative of completely clear and overcast days are derived. On this basis, empirical relationships allow the computation of monthly totals of radiation fluxes for an entire year from records of sunshine duration and temperature expected from the automatic stations.The larger part of the plateau is situated above 5400 m and has an albedo mostly in excess of 80%. Sub-freezing temperatures essentially limit ablation to the energetically expensive sublimation. For clear sky, daily totals of SW↓and LW↑↓ are of the order of 312 and 53 W m–2, respectively. With the albedo found, net short-wave radiation SW↑↓ becomes of the same general magnitude as LW↑↓, and the energy left for ablation is near to nil. Cloudiness would reduce both SW↑↓ and LW↑↓, thus largely compensating the effect on the residual net radiation, SWLW↑↓. This is consistent with ablation measurements. Over the larger area of the ice plateau, ablation may be close to zero in a first approximation; some ablation, including melting, takes place near the lower-lying rim of the ice cap, and calving off steep cliffs seems to provide a major mechanism for the disposal of the ice mass.

scholarly journals Heat-Budget Measurements on the Quelccaya Ice Cap, Peruvian Andes

1978 ◽  
Vol 20 (82) ◽  
pp. 85-97 ◽  
Author(s):  
Stefan Hastenrath
Keyword(s):  
Heat Budget ◽  
Sunshine Duration ◽  
Field Work ◽  
Short Wave ◽  
Wave Radiation ◽  
Peruvian Andes ◽  
Major Mechanism ◽  
Ice Cap ◽  
Wide Range ◽  
Quelccaya Ice Cap

Abstract During the June-August 1976 Quelccaya ice cap expedition, global, SW↓, and net long-wave radiation, LW↑↓, were measured through several complete day-night cycles, and for a wide range of cloudiness conditions. Field work further included albedo measurements along representative transects across the ice cap and lysimeter-type estimates of ablation. Automatic stations recording wind, temperature and sunshine duration were also installed. Daily totals of SW↓ and LW↑↓ representative of completely clear and overcast days are derived. On this basis, empirical relationships allow the computation of monthly totals of radiation fluxes for an entire year from records of sunshine duration and temperature expected from the automatic stations. The larger part of the plateau is situated above 5400 m and has an albedo mostly in excess of 80%. Sub-freezing temperatures essentially limit ablation to the energetically expensive sublimation. For clear sky, daily totals of SW↓and LW↑↓ are of the order of 312 and 53 W m–2, respectively. With the albedo found, net short-wave radiation SW↑↓ becomes of the same general magnitude as LW↑↓, and the energy left for ablation is near to nil. Cloudiness would reduce both SW↑↓ and LW↑↓, thus largely compensating the effect on the residual net radiation, SWLW↑↓. This is consistent with ablation measurements. Over the larger area of the ice plateau, ablation may be close to zero in a first approximation; some ablation, including melting, takes place near the lower-lying rim of the ice cap, and calving off steep cliffs seems to provide a major mechanism for the disposal of the ice mass.

scholarly journals Micro-Morphology of the Snow Surface at the Quelccaya Ice Cap, Peru

1981 ◽  
Vol 27 (97) ◽  
pp. 423-428 ◽  
Author(s):  
Stefan Hastenrath ◽  
Bruce Koci
Keyword(s):  
Heat Budget ◽  
Wave Radiation ◽  
Parallel Plates ◽  
Altitudinal Distribution ◽  
Ice Cap ◽  
June July ◽  
Quelccaya Ice Cap ◽  
Micro Morphology ◽  
Local Noon ◽  
Prolonged Absence

AbstractDuring the June-July 1979 expedition a large variety of micro-forms was observed at the surface of the Quelccaya ice cap, their altitudinal distribution being primarily controlled by the heat budget. At 5200–5300 m penitentes are best developed, with azimuth orientation and inclination of features conforming to the insolation geometry around local noon. At a westward-facing slope in 5360–5380 m a set of penitentes striking parallel to the contours is superimposed on the pattern dominating at the lower elevations. The ablation forms of penitentes give way to various deposition features above a transition zone around 5400 m in broad agreement with the larger net all-wave radiation and greater importance of melting at lower elevations. The succession of forms with an upward change from surface-parallel plates to elaborate dendritic forms appears to be controlled by the temperature conditions. The conspicuous development of forms encountered during the 1979 expedition appears characteristic of prolonged absence of fresh snow-fall subsequent to a season with abundant precipitation.

scholarly journals Micro-Morphology of the Snow Surface at the Quelccaya Ice Cap, Peru

1981 ◽  
Vol 27 (97) ◽  
pp. 423-428 ◽  
Author(s):  
Stefan Hastenrath ◽  
Bruce Koci
Keyword(s):  
Heat Budget ◽  
Wave Radiation ◽  
Parallel Plates ◽  
Altitudinal Distribution ◽  
Ice Cap ◽  
June July ◽  
Quelccaya Ice Cap ◽  
Micro Morphology ◽  
Local Noon ◽  
Prolonged Absence

AbstractDuring the June-July 1979 expedition a large variety of micro-forms was observed at the surface of the Quelccaya ice cap, their altitudinal distribution being primarily controlled by the heat budget. At 5200–5300 m penitentes are best developed, with azimuth orientation and inclination of features conforming to the insolation geometry around local noon. At a westward-facing slope in 5360–5380 m a set of penitentes striking parallel to the contours is superimposed on the pattern dominating at the lower elevations. The ablation forms of penitentes give way to various deposition features above a transition zone around 5400 m in broad agreement with the larger net all-wave radiation and greater importance of melting at lower elevations. The succession of forms with an upward change from surface-parallel plates to elaborate dendritic forms appears to be controlled by the temperature conditions. The conspicuous development of forms encountered during the 1979 expedition appears characteristic of prolonged absence of fresh snow-fall subsequent to a season with abundant precipitation.

scholarly journals The Glaciochemistry of Snow-Pits from Quelccaya Ice Cap, Peru, 1982

1985 ◽  
Vol 7 ◽  
pp. 84-88 ◽  
Author(s):  
W. Berry Lyons ◽  
A. Paul Mayewski ◽  
Lonnie G. Thompson ◽  
Boyd Allen
Keyword(s):  
Amazon Basin ◽  
Atomic Absorption Spectrophotometry ◽  
High Elevation ◽  
Common Source ◽  
Gaseous Emissions ◽  
Polar Ice ◽  
Peruvian Andes ◽  
Reactive Iron ◽  
Ice Cap ◽  
Quelccaya Ice Cap

We present glaciochemical data from a pilot study of two snow-pits from Quelccaya ice cap, Peruvian Andes. These are the first samples to be analyzed from Quelccaya for nitrate and sulfate by ion chromatography (IC), for nitrate-plus-nitrite, reactive silicate and reactive iron by colorimetry, and for sodium by atomic absorption spectrophotometry. The 3 m pits used in this study represent a one year record of mass accumulation and the 29 samples collected provide the first glaciochemical data from this area which can be compared with glaciochemical studies from other locations.Reactive iron, reactive silicate and sodium, and the profiles of >0.63μm microparticles from Thompson and others (1984) are coincident, suggesting that transport and deposition into this area of each species are controlled by similar processes. The common source is probably local, resulting from crustal weathering. In general, the reactive silicate values are lower than those observed in other alpine glacier ice. The highest sulfate and nitrate values were observed in the upper few centimeters of the snow-pit. Most of the sulfate concentrations were less than 3 μM and are similar to values obtained for fresh surface snows from Bolivia (Stallard and Edmond 1981). Since biological gaseous emissions are thought to be the major source of sulfur and nitrogen to the atmosphere over the Amazon basin, the sulfate and nitrate fluctuations may be due to seasonal biological input and/or seasonal shifts in wind direction bringing material to Quelccaya.With only one exception, the colorimetric nitrate-plus-nitrite data were higher than the IC nitrate data. Unfortunately, the IC analyses were conducted 81 d after the colorimetric analyses. The difference between the two data sets could be attributable to the following: (1) the colorimetric technique may yield erroneously high results as suggested for polar ice by Herron (1982), (2) the IC technique yields erroneously low results due, in part, to the possible exclusion of nitrite concentrations, and/or (3) nitrite was lost via biological removal during the 81 d period before the IC analyses. If the IC data are correct, the mean nitrate value is 0.4μΜ (n = 29). This value is similar to those reported from pre-industrial aged polar ice (Herron 1982). If the colorimetric mean value (1.1 μM) is correct, it is similar to colorimetrically determined values from other high-elevation alpine ice (Lyons and Mayewski 1983).

scholarly journals The Glaciochemistry of Snow-Pits from Quelccaya Ice Cap, Peru, 1982

1985 ◽  
Vol 7 ◽  
pp. 84-88 ◽  
Author(s):  
W. Berry Lyons ◽  
A. Paul Mayewski ◽  
Lonnie G. Thompson ◽  
Boyd Allen
Keyword(s):  
Amazon Basin ◽  
Atomic Absorption Spectrophotometry ◽  
High Elevation ◽  
Common Source ◽  
Gaseous Emissions ◽  
Polar Ice ◽  
Peruvian Andes ◽  
Reactive Iron ◽  
Ice Cap ◽  
Quelccaya Ice Cap

We present glaciochemical data from a pilot study of two snow-pits from Quelccaya ice cap, Peruvian Andes. These are the first samples to be analyzed from Quelccaya for nitrate and sulfate by ion chromatography (IC), for nitrate-plus-nitrite, reactive silicate and reactive iron by colorimetry, and for sodium by atomic absorption spectrophotometry. The 3 m pits used in this study represent a one year record of mass accumulation and the 29 samples collected provide the first glaciochemical data from this area which can be compared with glaciochemical studies from other locations. Reactive iron, reactive silicate and sodium, and the profiles of >0.63μm microparticles from Thompson and others (1984) are coincident, suggesting that transport and deposition into this area of each species are controlled by similar processes. The common source is probably local, resulting from crustal weathering. In general, the reactive silicate values are lower than those observed in other alpine glacier ice. The highest sulfate and nitrate values were observed in the upper few centimeters of the snow-pit. Most of the sulfate concentrations were less than 3 μM and are similar to values obtained for fresh surface snows from Bolivia (Stallard and Edmond 1981). Since biological gaseous emissions are thought to be the major source of sulfur and nitrogen to the atmosphere over the Amazon basin, the sulfate and nitrate fluctuations may be due to seasonal biological input and/or seasonal shifts in wind direction bringing material to Quelccaya. With only one exception, the colorimetric nitrate-plus-nitrite data were higher than the IC nitrate data. Unfortunately, the IC analyses were conducted 81 d after the colorimetric analyses. The difference between the two data sets could be attributable to the following: (1) the colorimetric technique may yield erroneously high results as suggested for polar ice by Herron (1982), (2) the IC technique yields erroneously low results due, in part, to the possible exclusion of nitrite concentrations, and/or (3) nitrite was lost via biological removal during the 81 d period before the IC analyses. If the IC data are correct, the mean nitrate value is 0.4μΜ (n = 29). This value is similar to those reported from pre-industrial aged polar ice (Herron 1982). If the colorimetric mean value (1.1 μM) is correct, it is similar to colorimetrically determined values from other high-elevation alpine ice (Lyons and Mayewski 1983).

scholarly journals Radiation and Cloud Observations on a High Arctic Plateau Ice Cap

1987 ◽  
Vol 33 (114) ◽  
pp. 162-168 ◽  
Author(s):  
M.C. Serreze ◽  
R.S. Bradley
Keyword(s):  
Surface Albedo ◽  
High Surface ◽  
High Arctic ◽  
Short Wave ◽  
Wave Radiation ◽  
Net Radiation ◽  
Short Wave Radiation ◽  
Ice Cap ◽  
Long Wave ◽  
Long Wave Radiation

AbstractHourly measurements of incoming short-wave and long-wave radiation, surface albedo, and net radiation were made on and around a plateau ice cap on north-eastern Ellesmere Island during the summers of 1982 and 1983. These data were stratified by cloud type and amount. All cloud types increased incoming long-wave radiation, especially low dense clouds, fog, and clouds associated with snowfall. Relative transmission of incoming short-wave radiation, expressed as a percentage of clear-sky radiation receipts, was high for all cloud types compared to clouds at lower latitudes. With high surface albedo (≥0.75), net radiation was strongly and positively correlated with net long-wave radiation but showed little relationship to net short-wave radiation. By contrast, with low surface albedo (≤0.20) net radiation was negatively correlated with net long-wave radiation but positively correlated with net short-wave radiation. Under high-albedo conditions, an increase in cloudiness led to higher values of net radiation but under low-albedo conditions net radiation decreased as cloud cover increased. Survival of a snow cover would seem to be favoured if the seasonal decline in albedo is accompanied by a corresponding increase in cloudiness.

scholarly journals Climate and basin drivers of seasonal river water temperature dynamics

2017 ◽  
Vol 21 (6) ◽  
pp. 3231-3247 ◽  
Author(s):  
Cédric L. R. Laizé ◽  
Cristian Bruna Meredith ◽  
Michael J. Dunbar ◽  
David M. Hannah
Keyword(s):  
Water Temperature ◽  
Air Temperature ◽  
Temporal Variability ◽  
Stream Water ◽  
Stream Temperature ◽  
Short Wave ◽  
Specific Humidity ◽  
Wave Radiation ◽  
Spatial And Temporal Variability ◽  
Wide Range

Abstract. Stream water temperature is a key control of many river processes (e.g. ecology, biogeochemistry, hydraulics) and services (e.g. power plant cooling, recreational use). Consequently, the effect of climate change and variability on stream temperature is a major scientific and practical concern. This paper aims (1) to improve the understanding of large-scale spatial and temporal variability in climate–water temperature associations, and (2) to assess explicitly the influence of basin properties as modifiers of these relationships. A dataset was assembled including six distinct modelled climatic variables (air temperature, downward short-wave and long-wave radiation, wind speed, specific humidity, and precipitation) and observed stream temperatures for the period 1984–2007 at 35 sites located on 21 rivers within 16 basins (Great Britain geographical extent); the study focuses on broad spatio-temporal patterns, and hence was based on 3-month-averaged data (i.e. seasonal). A wide range of basin properties was derived. Five models were fitted (all seasons, winter, spring, summer, and autumn). Both site and national spatial scales were investigated at once by using multi-level modelling with linear multiple regressions. Model selection used multi-model inference, which provides more robust models, based on sets of good models, rather than a single best model. Broad climate–water temperature associations common to all sites were obtained from the analysis of the fixed coefficients, while site-specific responses, i.e. random coefficients, were assessed against basin properties with analysis of variance (ANOVA). All six climate predictors investigated play a role as a control of water temperature. Air temperature and short-wave radiation are important for all models/seasons, while the other predictors are important for some models/seasons only. The form and strength of the climate–stream temperature association vary depending on season and on water temperature. The dominating climate drivers and physical processes may change across seasons and across the stream temperature range. The role of basin permeability, size, and elevation as modifiers of the climate–water temperature associations was confirmed; permeability has the primary influence, followed by size and elevation. Smaller, upland, and/or impermeable basins are the most influenced by atmospheric heat exchanges, while larger, lowland and permeable basins are the least influenced. The study showed the importance of accounting properly for the spatial and temporal variability of climate–stream temperature associations and their modification by basin properties.

scholarly journals Review of the status and mass changes of Himalayan-Karakoram glaciers

2018 ◽  
Vol 64 (243) ◽  
pp. 61-74 ◽  
Author(s):  
MOHD FAROOQ AZAM ◽  
PATRICK WAGNON ◽  
ETIENNE BERTHIER ◽  
CHRISTIAN VINCENT ◽  
KOJI FUJITA ◽  
...  
Keyword(s):  
Mass Balance ◽  
Short Wave ◽  
Wave Radiation ◽  
Radiation Balance ◽  
Wide Range ◽  
Debris Cover ◽  
The Status ◽  
Change Context ◽  
The 1960S ◽  
Volume Estimates

ABSTRACTWe present a comprehensive review of the status and changes in glacier length (since the 1850s), area and mass (since the 1960s) along the Himalayan-Karakoram (HK) region and their climate-change context. A quantitative reliability classification of the field-based mass-balance series is developed. Glaciological mass balances agree better with remotely sensed balances when we make an objective, systematic exclusion of likely flawed mass-balance series. The Himalayan mean glaciological mass budget was similar to the global average until 2000, and likely less negative after 2000. Mass wastage in the Himalaya resulted in increasing debris cover, the growth of glacial lakes and possibly decreasing ice velocities. Geodetic measurements indicate nearly balanced mass budgets for Karakoram glaciers since the 1970s, consistent with the unchanged extent of supraglacial debris-cover. Himalayan glaciers seem to be sensitive to precipitation partly through the albedo feedback on the short-wave radiation balance. Melt contributions from HK glaciers should increase until 2050 and then decrease, though a wide range of present-day area and volume estimates propagates large uncertainties in the future runoff. This review reflects an increasing understanding of HK glaciers and highlights the remaining challenges.

scholarly journals Radiation and Cloud Observations on a High Arctic Plateau Ice Cap

1987 ◽  
Vol 33 (114) ◽  
pp. 162-168 ◽  
Author(s):  
M.C. Serreze ◽  
R.S. Bradley
Keyword(s):  
Surface Albedo ◽  
High Surface ◽  
High Arctic ◽  
Short Wave ◽  
Wave Radiation ◽  
Net Radiation ◽  
Short Wave Radiation ◽  
Ice Cap ◽  
Long Wave ◽  
Long Wave Radiation

AbstractHourly measurements of incoming short-wave and long-wave radiation, surface albedo, and net radiation were made on and around a plateau ice cap on north-eastern Ellesmere Island during the summers of 1982 and 1983. These data were stratified by cloud type and amount. All cloud types increased incoming long-wave radiation, especially low dense clouds, fog, and clouds associated with snowfall. Relative transmission of incoming short-wave radiation, expressed as a percentage of clear-sky radiation receipts, was high for all cloud types compared to clouds at lower latitudes. With high surface albedo (≥0.75), net radiation was strongly and positively correlated with net long-wave radiation but showed little relationship to net short-wave radiation. By contrast, with low surface albedo (≤0.20) net radiation was negatively correlated with net long-wave radiation but positively correlated with net short-wave radiation. Under high-albedo conditions, an increase in cloudiness led to higher values of net radiation but under low-albedo conditions net radiation decreased as cloud cover increased. Survival of a snow cover would seem to be favoured if the seasonal decline in albedo is accompanied by a corresponding increase in cloudiness.

Sign in / Sign up

Export Citation Format

Share Document