Effects of Snow and Ice on the Annual Cycles of Heat and Light in Saqvaqjuac Lakes

1987 ◽  
Vol 44 (8) ◽  
pp. 1451-1461 ◽  
Author(s):  
Harold E. Welch ◽  
John A. Legault ◽  
Martin A. Bergmann

The annual cycles of temperature, ice and snow cover, and light are described for small Saqvaqjuac lakes (63°30′N). Summer thermal stratification occurred but was not persistent. Annual heat budgets were slightly higher than for temperate lakes and increased with increasing mean depth; latent heat of fusion constituted one half to one third of the total heat flow. Ice thickness reached a maximum of 1.6–2.2 m, depending upon winter snow cover, and a thin layer (≈5 cm) of white ice occurred in some years. Ice-out was a partial function of mean June temperature. The open-water season lasted 2–3 ms. Light attenuation through white and candled ice, snow, and water was measured. About 28% of the annual surface irradiance penetrated the unfrozen water, about half that which would have been absorbed under ice-free conditions. Extinction coefficients were inversely correlated with mean depth and positively correlated with nutrient status.

2016 ◽  
Vol 74 (12) ◽  
pp. 2773-2783 ◽  
Author(s):  
Yang Fang ◽  
Li Changyou ◽  
Matti Leppäranta ◽  
Shi Xiaonghong ◽  
Zhao Shengnan ◽  
...  

Nutrients may be eliminated from ice when liquid water is freezing, resulting in enhanced concentrations in the unfrozen water. The nutrients diluted from the ice may contribute to accumulated concentrations in sediment during winter and an increased risk of algae blooms during the following spring and summer. The objective of this study was to evaluate the influence of ice cover on nitrogen (N) and phosphorus (P) concentrations in the water and sediment of a shallow lake, through an examination of Ulansuhai Lake, northern China, from the period of open water to ice season in 2011–2013. The N and P concentrations were between two and five times higher, and between two and eight times higher, than in unfrozen lakes, respectively. As the ice thickness grew, contents of total N and total P showed C-shaped profiles in the ice, and were lower in the middle layer and higher in the bottom and surface layers. Most of the nutrients were released from the ice to liquid water. The results confirm that ice can cause the nutrient concentrations in water and sediment during winter to increase dramatically, thereby significantly impacting on processes in the water environment of shallow lakes.


1986 ◽  
Vol 8 ◽  
pp. 78-81 ◽  
Author(s):  
W. Haeberli ◽  
F. Epifani

Techniques for mapping the distribution of buried glacier ice are discussed and the results, from a study carried out within the framework of flood protection work in the Italian Alps, are presented. Bottom temperatures of the winter snow cover (BTS) primarily indicate the heat flow conditions in the underlying ground and mainly depend on the presence or absence of an ice layer beneath the surface. Determination of BTS values is therefore an inexpensive method for quickly mapping the near-surface underground ice in areas where there is 1 m or more of winter snow cover. At greater depths, and/or when more detail is required, geoelectrical resistivity soundings and seismic refraction soundings are most commonly used to investigate underground ice. A combination of the two sounding techniques allows the vertical extent and the main characteristics (frozen ground, dead glacier ice) to be determined in at least a semi-quantitative way. Complications mainly arise from irregularity in the horizontal extension of the studied underground ice bodies, and they may have to be overcome by expensive core drillings and borehole measurements. Widespread occurrence of buried glacier ice was observed in morainic deposits, surrounding an ice-dammed lake near Macugnaga, Italy.


2015 ◽  
Vol 15 (3) ◽  
pp. 1411-1420 ◽  
Author(s):  
T. F. Bidleman ◽  
L. M. Jantunen ◽  
H. Hung ◽  
J. Ma ◽  
G. A. Stern ◽  
...  

Abstract. Air samples collected during 1994–2000 at the Canadian Arctic air monitoring station Alert (82°30' N, 62°20' W) were analysed by enantiospecific gas chromatography–mass spectrometry for α-hexachlorocyclohexane (α-HCH), trans-chlordane (TC) and cis-chlordane (CC). Results were expressed as enantiomer fractions (EF = peak areas of (+)/[(+) + (−)] enantiomers), where EFs = 0.5, < 0.5 and > 0.5 indicate racemic composition, and preferential depletion of (+) and (−) enantiomers, respectively. Long-term average EFs were close to racemic values for α -HCH (0.504 ± 0.004, n = 197) and CC (0.505 ± 0.004, n = 162), and deviated farther from racemic for TC (0.470 ± 0.013, n = 165). Digital filtration analysis revealed annual cycles of lower α-HCH EFs in summer–fall and higher EFs in winter–spring. These cycles suggest volatilization of partially degraded α-HCH with EF < 0.5 from open water and advection to Alert during the warm season, and background transport of α-HCH with EF > 0.5 during the cold season. The contribution of sea-volatilized α-HCH was only 11% at Alert, vs. 32% at Resolute Bay (74.68° N, 94.90° W) in 1999. EFs of TC also followed annual cycles of lower and higher values in the warm and cold seasons. These were in phase with low and high cycles of the TC/CC ratio (expressed as FTC = TC/(TC+CC)), which suggests greater contribution of microbially "weathered" TC in summer–fall versus winter–spring. CC was closer to racemic than TC and displayed seasonal cycles only in 1997–1998. EF profiles are likely to change with rising contribution of secondary emission sources, weathering of residues in the environment, and loss of ice cover in the Arctic. Enantiomer-specific analysis could provide added forensic capability to air monitoring programs.


1994 ◽  
Vol 19 ◽  
pp. 1-6 ◽  
Author(s):  
He Yuanqing ◽  
Wilfred H. Theakstone

Winter snow cover at Austre Okstindbreen is influenced strongly by patterns of atmospheric circulation, and by air temperatures during precipitation. Differences of circulation over the North Atlantic and Scandinavia during the winters of 1988–89 and 1989–90 were reflected in the ionic and isotopic composition of snow that accumulated at the glacier. Early summer ablation did not remove, or smooth out, all the initial stratigraphic differences. In the first half of the 1988–89 winter, most air masses took a relatively short route between a marine source and Okstindan; late winter snowfalls were from air masses which had taken a longer continental route. The snow that accumulated in the first half of the 1989–90 winter was associated with air masses which had followed longer continental routes, and so brought higher concentrations of impurities from forests, lakes and crustal material. The ablation season began earlier in 1990 than in 1989, and summer winds and rain supplied more impurities to the snowpack surface.


1970 ◽  
Vol 9 (55) ◽  
pp. 154-156
Author(s):  
James D. Bergen

AbstractThe extinction coefficient for the transmission of light through snow cover is related to the grain size and density of the snow cover. The connection is made by means of an empirical relation between the latter parameters and the air permeability and by the Carmen–Kozney relation between the air permeability and specific surface of a porous medium. The results are compared with a set of measurements found in the literature with fair agreement between the predicted and measured values of the extinction coefficient.


2020 ◽  
Vol 12 (17) ◽  
pp. 2716
Author(s):  
Shuang Liang ◽  
Xiaofeng Li ◽  
Xingming Zheng ◽  
Tao Jiang ◽  
Xiaojie Li ◽  
...  

Spring soil moisture (SM) is of great importance for monitoring agricultural drought and waterlogging in farmland areas. While winter snow cover has an important impact on spring SM, relatively little research has examined the correlation between winter snow cover and spring SM in great detail. To understand the effects of snow cover on SM over farmland, the relationship between winter snow cover parameters (maximum snow depth (MSD) and average snow depth (ASD)) and spring SM in Northeast China was examined based on 30 year passive microwave snow depth (SD) and SM remote-sensing products. Linear regression models based on winter snow cover were established to predict spring SM. Moreover, 4 year SD and SM data were applied to validate the performance of the linear regression models. Additionally, the effects of meteorological factors on spring SM also were analyzed using multiparameter linear regression models. Finally, as a specific application, the best-performing model was used to predict the probability of spring drought and waterlogging in farmland in Northeast China. Our results illustrated the positive effects of winter snow cover on spring SM. The average correlation coefficient (R) of winter snow cover and spring SM was above 0.5 (significant at a 95% confidence level) over farmland. The performance of the relationship between snow cover and SM in April was better than that in May. Compared to the multiparameter linear regression models in terms of fitting coefficient, MSD can be used as an important snow parameter to predict spring drought and waterlogging probability in April. Specifically, if the relative SM threshold is 50% when spring drought occurs in April, the prediction probability of the linear regression model concerning snow cover and spring SM can reach 74%. This study improved our understanding of the effects of winter snow cover on spring SM and will be beneficial for further studies on the prediction of spring drought.


2003 ◽  
Vol 34 (1-2) ◽  
pp. 33-50 ◽  
Author(s):  
S.V. Semovski ◽  
N. Yu Mogilev

The generation and sample applications of a set of multispectral remotely sensed products for investigations of Lake Baikal's ice cover variability are described. During the period from mid-January to the end of April, the lake is completely covered with ice, and by analyzing satellite information it is possible to investigate in detail the distribution and dynamics of the main types of snow and ice cover. Different ice cover classes and unfrozen water distributions are estimated from calibrated and navigated NOAA AVHRR 1.1-km imagery of Lake Baikal for January 1994 through May 1999. The processing strategy and characteristics of the products are reviewed. The utility of this type of multiparameter dataset for modelling applications and process studies is discussed. ERS SAR and Resurs images are used for detailed representation of different ice classes distributions.


1998 ◽  
Vol 103 (C11) ◽  
pp. 24837-24855 ◽  
Author(s):  
R. A. Massom ◽  
V. I. Lytle ◽  
A. P. Worby ◽  
I. Allison

2018 ◽  
Vol 93 ◽  
pp. 93-96 ◽  
Author(s):  
Elizabeth M. Hillard ◽  
Alison C. Edmund ◽  
Joanne C. Crawford ◽  
Clayton K. Nielsen ◽  
Eric M. Schauber ◽  
...  
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document