River and lake ice in the Arctic

From The Encyclopedia of Earth
Jump to: navigation, search


Published: February 8, 2010, 7:51 pm
Updated: May 7, 2012, 5:48 pm
Author: International Arctic Science Committee
Topic Editor: Sjaak Slanina
Topics:
Camel-icon.png

This is Section 6.7 of the Arctic Climate Impact Assessment.
Lead Author: John E.Walsh; Contributing Authors: Oleg Anisimov, Jon Ove M. Hagen,Thor Jakobsson, Johannes Oerlemans,Terry D. Prowse,Vladimir Romanovsky, Nina Savelieva,Mark Serreze, Alex Shiklomanov, Igor Shiklomanov, Steven Solomon; Consulting Authors: Anthony Arendt, David Atkinson, Michael N. Demuth, Julian Dowdeswell, Mark Dyurgerov, Andrey Glazovsky, Roy M. Koerner, Mark Meier, Niels Reeh, Oddur Sigur0sson, Konrad Steffen, Martin Truffer

Background (6.7.1)

Ice cover plays a fundamental role in the biological, chemical, and physical processes of arctic freshwater systems[1] (Section 8.2 (River and lake ice in the Arctic)). In particular, freshwater ice is integral to the hydrological cycle of northern systems. The duration and composition of lake ice, for example, controls the seasonal heat budget of lake systems. This in turn determines the magnitude and timing of evaporation from these systems, ranging from small ponds to large lakes; storage levels in the latter also control the flow of some of the major arctic rivers, such as the Mackenzie. Similarly, river ice has a significant influence on the timing and magnitude of extreme hydrological events, such as low flows[2] and floods[3]. Many of these hydrological events are due more to in-channel ice effects than to landscape runoff processes[4].

Lake ice and river ice also serve as climate indicators, and long-term records of these variables provide useful proxy climate data. For some sites in northern Finland and Siberia, the dates of ice formation and breakup have been recorded since the 16th century[5]. Given the proxy potential of freshwater ice, considerable recent research has focused on the use of remote sensing for documenting ice phenology[6] and on the hemispheric process-based modeling of lake-ice patterns for assessing the effects of climate variability and change[7].

Freeze-over processes differ significantly between lakes and rivers, although the timing of each depends on the magnitude of the open-water heat storage and the autumn rate of cooling. The stratigraphy of lake ice is relatively simple, usually consisting of clear columnar ice, an intermediate layer of translucent granular ice, and a surface layer of snow[8]. In contrast, river ice forms by the dynamic accumulation of various ice forms and is characterized by a more complex vertical and horizontal ice structure[9]. The thickness and physical characteristics (e.g., optical and mechanical) of the ice cover exert significant control over the thermal and mass balance of the underlying water bodies, and produce important hydrological responses. These in turn affect a number of chemical and biological processes as discussed in [[Section 8.2 (River and lake ice in the Arctic)]2].

Freeze-up is controlled by a combination of atmospheric heat fluxes. Of all meteorological variables, freeze-up timing correlates best with air temperature in the preceding weeks to months[10]. In the case of lakes, area and depth are important determinants of the heat budget and therefore the timing of freeze-up[11]. Depth is not as important a factor in determining the timing of lake-ice breakup as it is for freeze-up[12]; the timing of lake breakup is determined more by the energy balance characterizing the melt period leading up to the event[13]. Ice breakup on rivers is a more complex process than that on lakes and, because it is not as strongly related to a single meteorological variable such as air temperature, it is less valuable as a climatic indicator[14]. For example, the primary determinant of mechanical strength is insolation-induced decay, which is dependent on solar radiation and ice-cover composition[15]. The latter, which can be influenced by snow loading and the generation of surface "snow-ice", also controls the surface albedo and the effectiveness of insolation in reducing ice strength. Ice breakup on northern rivers usually coincides with spring melt of the catchment snow cover and produces the major hydrological event of the year[16].

The most common approach to projecting breakup timing on lakes and rivers employs an air temperature index, such as accumulated degree-days, which reflects the amount of ice deterioration and, in the case of rivers, the magnitude of the snowmelt flood wave[17]. While recognizing that numerous physical and climatological factors influence the rates and timing of ice formation and decay processes, Magnuson et al.[18] estimated the change in freeze-up and breakup dates relative to a change in air temperature in the preceding weeks or months to be approximately 5 days/°C based on results from a number of lake- and river-ice case studies. Estimating the severity of breakup requires the use of a wider range of meteorological factors[19].

Ice jams frequently form on rivers, and, because of their high hydraulic resistance, produce flood levels that often far exceed those for equivalent discharge under open-water conditions, usually with a high recurrence interval[20]. Dredging, blasting, and aerial bombing have been used to try to dislodge ice jams, with varying degrees of success, but these approaches often produce local environmental damage[21].

One of the most persistent effects of ice on river hydrology is its influence on water levels. Although the additional hydraulic resistance of a stable ice cover tends to elevate channel water levels, the greatest effect occurs when the ice cover is hydraulically rough, as it often is following a dynamically active freeze-up period. In combination with rapid freezing, hydraulic staging of the ice cover can extract significant amounts of water such that a period of low flow prevails. The release of water stored during this period can significantly augment the spring freshet[22].

Recent and ongoing changes (6.7.2)

Fig. 6.31. Ten-year running means of freeze-up (top) and breakup (bottom) dates of selected lakes and rivers in the Northern Hemisphere: Mackenzie River (Canada), Red River (Canada), Kallavesi Lake (Finland), Lake Mendota (U.S.), Lake Suwa (Japan),Angara River (eastern Russia), Lake Baikal (eastern Russia), Grand Traverse Bay (Lake Michigan, United States), and Tornionjoki River (Finland)[23].

Although changes in the thickness and composition of freshwater ice or in the severity of freeze-up and breakup events can have significant implications for numerous physical and ecological processes, available documentation of past changes is largely limited to simple observations of the timing of freeze-up and breakup. Such data are, however, useful indicators of climate change, although long-term records are relatively scarce. Magnuson et al.[24] assessed freeze-up and breakup trends for Northern Hemisphere lakes and rivers that had records spanning at least 100 years within the period from 1846 to 1995 (only three sites had records beginning prior to 1800). Of the 26 rivers and lakes included in the study, most are located south of 60° N. Over the 150-year period, average freeze-up dates were delayed by 5.8 d/100 yr and average breakup dates advanced by 6.3 d/100 yr, corresponding to an increase in air temperature of about 1.2°C/100 yr. Magnuson et al.[25] further observed that the few available longer time series indicate that a trend of reduced ice cover began as early as the 16th century, although rates of change increased after approximately 1850. Figure 6.31 shows the time series of freeze-up and breakup dates for a sample of the rivers and lakes studied. The high-latitude water bodies in Fig. 6.31 (the Mackenzie River in Canada and Kallavesi Lake in Finland) both show general trends toward later freeze-up dates, although decadal-scale variations make trends sensitive to the beginning and end dates of the calculations. Similar sensitivity is found in the trend toward earlier breakup of Kallavesi Lake, and in the breakup date of the Tanana River at Nenana, Alaska, for which the time series in Fig. 6.32 shows interannual and decadal-scale variations superimposed on the trend toward earlier breakup.

Most of the very long-term records analyzed by Magnuson et al.[26] are geographically diverse and give little insight into potential regional trends. Moreover, few sites are even located above 60° N. To gain a better understanding of recent and ongoing changes at high latitudes, records shorter than 150 years must be examined. The most comprehensive regional evaluation of freeze-up and breakup dates that includes areas of the Arctic and subarctic was conducted by Ginzburg et al.[27] and Soldatova[28], using data from about 1893 to 1985 for homogenous hydrological regions of the Former Soviet Union. Although appreciable interdecadal variability was found, significant long-term spatial patterns and temporal trends in freeze-up and breakup dates were identified for the period. The most significant regional trend was toward later river-ice freeze-up dates in the European part of the Former Soviet Union and western Siberia. A weaker but still significant trend toward earlier freeze-up dates was found for portions of rivers (e.g., the Yenisey and Lena) in central and eastern Siberia[29]. A similar broad-scale spatial pattern is evident for breakup dates[30]. Breakup on major rivers in the European part of the Former Soviet Union and western Siberia advanced by an average of 7 to 10 d/100 yr, resulting in a reduction in ice-season duration of up to a month. However, some rivers in central and eastern Siberia exhibited an opposing trend: later breakup dates and hence an increase in ice-season duration. Freeze-up and breakup dates were well correlated (r2=0.6–0.7) with the mean air temperature in the preceding autumn and spring months, respectively. A gradual advancement in the date of breakup has been documented for lakes in southern Finland[31] and rivers in northern Sweden/Finland and Latvia[32].

Fig. 6.32. Time series of the breakup date of the Tanana River at Nenana, Alaska (modifed from W. Chapman[33] using data from the National Snow and Ice Data Center[34]).

In northwestern North America, studies of the Tanana River (1917–2000)[35] and the Yukon River (1896–1998)[36] indicate that the average date of breakup has advanced by approximately 5 d/100 yr. This trend is characterized by a number of interdecadal cycles. Zhang X. et al.[37] conducted a Canada-wide assessment of river freezeup, breakup, and ice duration using records spanning 50 years or less. The major spatial distinction in breakup timing was between eastern and western sites, with the western sites (e.g., the Yukon and other western rivers) showing trends towards earlier breakup dates. Notably, there was also a nation-wide trend to earlier freeze-up dates.

Smith[38] conducted a study of shorter-term records from nine major arctic and subarctic rivers in Russia. Some trends were opposite to those found for the longer-term and broader regional studies of Ginzburg et al.[39] and Soldatova[40], possibly because of the shorter record lengths (54 to 71 years) or differences resulting from site-specific factors. In particular, earlier rather than later freeze-up dates were found for rivers west of and including the Yenisey, whereas later freeze-up dates were observed for rivers in far eastern Siberia. Although Smith[41] found no statistically significant shifts in breakup timing, there were significant shifts toward an earlier melt onset, producing a trend toward a longer period of pre-breakup melt. According to breakup theory, a longer melt period favors "thermal" breakups – low-energy events that are less likely to produce floods and related disturbances[42]. Similar analyses, or studies that focus on breakup characteristics beyond simple timing, have not been conducted elsewhere.

Projected changes (6.7.3)

Although many case studies of existing data show relationships between the timing of freeze-up and breakup and the preceding autumn and spring air [[temperature]s], such relationships are not necessarily temporally stable. For example, Livingstone[43] found that the influence of April air temperatures on Lake Baikal breakup dates has varied considerably over the past 100 years, and accounts for only 12 to 39% of the variance in breakup dates. Furthermore, there is no guarantee that such empirical relationships will hold for future climatic conditions, particularly if they are characterized by significant changes in the composition of the major heat fluxes[44].

Considering only the projected changes in air temperature, the general pattern of change in freshwater ice will be a general reduction in ice cover on arctic rivers and lakes. This reduction will be greatest in the regions of greatest warming. The warming varies somewhat from model to model, but is generally larger in the northern-most land areas than in the subpolar land areas. None of the five ACIA-designated models projects a cooling over northern terrestrial regions. However, the reduction in river and lake ice may be modified by changes in precipitation (including snowfall) over the 21st century, and the projected changes in precipitation vary substantially from model to model.

Freeze-up and breakup dates are projected to respond more strongly to warming than to cooling because of albedo–radiation feedbacks[45]. However, changes in winter precipitation will modify this pattern. Increased snowfall should lead to a delay in breakup owing to additions of white ice and longer-lasting higher albedo. Conversely, decreased snowfall should advance breakup owing to lower spring albedo, although reduced insulation in winter could also lead to enhanced ice growth. Projecting specific regional responses requires detailed physical modeling (employing multi-variable meteorological input) of changes not only in winter snow and ice conditions, but also in the open-water heat budgets that strongly influence freezeup timing and subsequent ice growth. Projections for river ice are even more complex because the heat budgets of contributing catchment flow must be considered, together with changes in the timing and magnitude of flow that control many of the important river-ice hydrological extremes. Prowse and Beltaos[46] reviewed a range of the complex interacting hydraulic, mechanical, and thermal changes that could result from shifts in temperature and precipitation. In general, as for lake ice, the duration and composition of river-ice cover would change, as would the potential for extreme conditions during freeze-up and breakup.

Impacts of projected changes (6.7.4)

On other parts of the physical system

A number of physical, biological, and chemical changes will result from changes in the timing, composition, and duration of lake- and river-ice cover. Some of the most direct changes will be shifts in the thermal and radiation regimes, which can have indirect effects on freshwater habitat and quality (e.g., water temperature and dissolved oxygen). Hydrological processes (e.g. Discharge timing, evaporation) are also likely to be affected. For northern peatlands, ice-induced changes in openwater evaporation and resultant water levels are likely to determine whether they become sources or sinks of CO2 and CH4 (Section 7.5.3 (River and lake ice in the Arctic)). For regions with extensive lake cover and substantial winter water storage, changes in the timing and magnitude of winter snowfall will produce corresponding changes in the winter pulsing of river discharge. Changes in the timing and severity of freeze-up and breakup will alter the hydrological extremes (e.g., low flows and floods) that dominate the flow regime of northern systems. A change in breakup intensity will also alter channel-forming processes, as well as levels of suspended sediment ultimately carried to the Arctic Ocean.

On ecosystems

Biological and chemical changes are likely to result from changes in the timing and duration of lake- and river-ice cover (Section 8.4 (River and lake ice in the Arctic)). A change in breakup intensity will affect the supply of floodwater, organic carbon, and nutrients to riparian zones; the ecosystem health of river deltas is particularly dependent on such fluxes.

On people

Winter roads that use the ice cover of interconnected lakes and rivers service extensive areas of the north, particularly those areas being explored or developed by resource extraction industries. Any changes in the thickness, composition, and/or mechanical strength of such ice will have major transportation and financial implications. The greatest economic impact is likely to stem from a decrease in ice thickness and bearing capacity, which could severely restrict the size and load limit of vehicular traffic. Changing ice regimes will also affect shipping operations, particularly on large Russian rivers where icebreakers are employed to extend the shipping season to northern towns and industries. Considering the high operational costs of ice breaking, any reduction in the duration of the ice season or breakup severity should translate into significant cost savings.

Changes in the ice regime will also require changes in operating strategies for hydroelectric installations, both at the generating facility to reduce impacts from ice (e.g., accumulations of frazil, the slushy ice-water mixture that develops when turbulent water starts to freeze), and for management of downstream flows to minimize negative impacts on river ecology and infrastructure. Major economic savings are likely to accrue to hydroelectric facilities if climate change reduces the length of the ice season. However, if the length of the ice season is reduced, the increased time required for freeze-up to a hydraulically stable ice cover will have at least some negative economic consequences (e.g., the necessary reductions in peak generating capacity during the freeze-up period).

Critical research needs (6.7.5)

Critical research needs with regard to river and lake ice include improved understanding of the interacting hydrological and meteorological controls on freeze-up and breakup, reliable projections of changes in these controls over the 21st century, and further refinement of models of lake-ice growth and ablation[47] and river-ice dynamics[48] for use in forecasting future conditions. There is a particular need for more credible model projections of precipitation and surface solar radiative fluxes. Snowfall can influence river and lake ice by changing the composition of the ice cover and, through its effects on insulation and insolation, ice growth and ablation rates. Accumulated winter precipitation also determines the magnitude of the spring runoff, which controls the severity of breakup and associated ice-jam flooding. Surface radiative fluxes are key controls of river and lake ice, affecting both rates of ablation and changes in mechanical strength of the ice cover. However, model projections of future radiative fluxes, which will depend strongly on changes in cloudiness, are highly uncertain.

Chapter 6: Cryosphere and Hydrology

6.1. Introduction (River and lake ice in the Arctic)
6.2. Precipitation and evapotranspiration
6.3. Sea ice (Sea ice in the Arctic)
6.4. Snow cover
6.5. Glaciers and ice sheets
6.6. Permafrost (Permafrost in the Arctic)
6.7. River and lake ice
6.8. Freshwater discharge
6.9. Sea-level rise and coastal stability

References

Citation

Committee, I. (2012). River and lake ice in the Arctic. Retrieved from http://editors.eol.org/eoearth/wiki/River_and_lake_ice_in_the_Arctic
  1. ↑ Adams, W.P., 1981. Snow and ice on lakes. In: D.M. Gray and D.H. Male (eds.). Handbook of Snow, pp. 437–474. Pergamon Press.–Magnuson, J.J., K.E. Webster, R. A. Assel, C.J. Bowser, P.J. Dillon, J.G. Eaton, H.E. Evans, E.J. Fee, R.I. Hall, L.R. Mortsch, D. W. Schindler and F.H. Quinn, 1997. Potential effects of climate changes on aquatic systems: Laurentian Great Lakes and Precambrian Shield Region. In: C.E. Cushing (ed.). Freshwater Ecosystems and Climate Change in North America, pp. 7–53. John Wiley and Sons.–Prowse, T.D., 2001. River-ice ecology: Part A) Hydrologic, geomorphic and water-quality aspects. Journal of Cold Regions Engineering, 15(1):1–16.–Schindler, D. W., S.E. Bayley, B.R. Parker, K.G. Beaty, D.R. Cruikshank, E.J. Fee, E.U. Schindler and M.P. Stainton, 1996. The effects of climate warming on the properties of boreal lakes and streams at the Experimental Lakes Area, northwestern Ontario. Limnology and Oceanography, 41:1004–1017.–Willemse, N. W. and T.E. Tornqvist, 1999. Holocene century-scale temperature variability from West Greenland lake records. Geology, 27(7):580–584.
  2. ↑ Prowse, T.D. and T. Carter, 2002. Significance of ice-induced hydraulic storage to spring runoff: a case study of the Mackenzie River. Hydrological Processes 16(4):779–788.
  3. ↑ Prowse, T.D. and S. Beltaos, 2002. Climatic control of river-ice hydrology: a review. Hydrological Processes, 16(4):805–822.
  4. ↑ Gerard, R., 1990. Hydrology of floating ice. In: T.D. Prowse and C.S.O. Ommanney (eds.). Northern Hydrology: Canadian Perspectives, pp. 103–134. NHRI Science Report No. 1. National Hydrology Research Institute, Environment Canada.–Prowse, T.D., 1994. The environmental significance of ice to cold-regions streamflow. Freshwater Biology, 32(2):241–260.
  5. ↑ Magnuson, J.J., D.M. Robertson, R.H. Wynne, B.J. Benson, D.M. Livingstone, T. Arai, R. A. Assel, R.D. Barry, V. Card, E. Kuusisto, N.G. Granin, T.D. Prowse, K.M. Stewart and V.S. Vuglinski, 2000. Ice cover phenologies of lakes and rivers in the Northern Hemisphere and climate warming. Science, 289(5485):1743–1746.
  6. ↑ Wynn, R.H. and T.M. Lillesand, 1993. Satellite observation of lake ice as a climatic indicator: initial results from state-wide monitoring in Wisconsin. Photogrammetric Engineering and Remote Sensing, 59:1023–1031.
  7. ↑ Walsh, S.E., S.J. Vavrus, J. A. Foley, A. Fisher, R.H. Wynne and J.D. Lenters, 1998. Global patterns of lake ice phenology and climate: model simulations and observations. Journal of Geophysical Research, 103:28825–28837.
  8. ↑ Adams, W.P., 1981. Snow and ice on lakes. In: D.M. Gray and D.H. Male (eds.). Handbook of Snow, pp. 437–474. Pergamon Press.
  9. ↑ Prowse, T.D., 1995. River ice processes. In: S. Beltaos (ed.). River Ice Jams, pp. 29–70. Water Resources Publications, USA.
  10. ↑ Palecki, M. A. and R.G. Barry, 1986. Freeze-up and break-up of lakes as an index of temperature changes during the transition seasons: a case study for Finland. Journal of Climate and Applied Meteorology, 25:893–902.–Reycraft, J. and W. Skinner, 1993. Canadian lake ice conditions: An indicator of climate variability. Climatic Perspectives, 15:9–15.
  11. ↑ Stewart, K.M. and R.K. Haugen, 1990. Influence of lake morphometry on ice dates. Internationale Vereinigung fur Theoretische und Angewandte Limnologie:Verhandlungen, 24:122–127.
  12. ↑ Vavrus, S.J., R.H. Wynne and J. A. Foley, 1996. Measuring the sensitivity of southern Wisconsin lake ice to climate variations and lake depth using a numerical model. Limnology and Oceanography, 41:822–831.–Wynn, R.H., J.J. Magnuson, M.K. Clayton, T.M. Lillesand and D.C. Rodman, 1996. Determinants of temporal coherence in the satellite-derived 1987–1994 ice breakup dates of lakes on the Laurentian Shield. Limnology and Oceanography, 41:831–838.
  13. ↑ Anderson, W.L., D.M. Robertson and J.J. Magnuson, 1996. Evidence of recent warming and El Niño-related variations in ice breakup of Wisconsin lakes. Limnology and Oceanography, 41:815–821.–Assel, R. A. and D.M. Robertson, 1995. Changes in winter air temperatures near Lake Michigan, 1851–1993, as determined from regional lake-ice records. Limnology and Oceanography, 40:165–176.
  14. ↑ Barry, R.G., 1984. Possible CO2-induced warming effects on the cryosphere. In: N.-A. Morner and W. Karlin (eds.). Climatic Changes on a Yearly to Millennial Basis, pp. 571–604. D. Reidel.
  15. ↑ Prowse, T.D. and M.N. Demuth, 1993. Strength variability of major river-ice types. Nordic Hydrology, 24(3):169–182.
  16. ↑ Church, M., 1974. Hydrology and permafrost with reference to northern North America. In: Permafrost Hydrology, Proceedings of Workshop Seminar 1974, pp. 7–20. Canadian National Committee for the International Hydrological Decade, Ottawa.–Prowse, T.D., 1994. The environmental significance of ice to cold-regions streamflow. Freshwater Biology, 32(2):241–260.
  17. ↑ Prowse, T.D., 1995. River ice processes. In: S. Beltaos (ed.). River Ice Jams, pp. 29–70. Water Resources Publications, USA.
  18. ↑ Magnuson, J.J., D.M. Robertson, R.H. Wynne, B.J. Benson, D.M. Livingstone, T. Arai, R. A. Assel, R.D. Barry, V. Card, E. Kuusisto, N.G. Granin, T.D. Prowse, K.M. Stewart and V.S. Vuglinski, 2000. Ice cover phenologies of lakes and rivers in the Northern Hemisphere and climate warming. Science, 289(5485):1743–1746.
  19. ↑ Gray, D.M. and T.D. Prowse, 1993. Snow and floating ice. In: D. Maidment (ed.). Handbook of Hydrology, pp. 7.1–7.58. McGraw-Hill.
  20. ↑ Beltaos, S. (ed.), 1995. River Ice Jams. Water Resources Publications, Colorado, 372pp.–Prowse, T.D. and S. Beltaos, 2002. Climatic control of river-ice hydrology: a review. Hydrological Processes, 16(4):805–822.
  21. ↑ Burrell, B.C., 1995. Mitigation. In: S. Beltaos (ed.). River Ice Jams, pp. 205–239. Water Resources Publications, Colorado.
  22. ↑ Prowse, T.D. and T. Carter, 2002. Significance of ice-induced hydraulic storage to spring runoff: a case study of the Mackenzie River. Hydrological Processes 16(4):779–788.
  23. ↑ Magnuson, J.J., D.M. Robertson, R.H. Wynne, B.J. Benson, D.M. Livingstone, T. Arai, R. A. Assel, R.D. Barry, V. Card, E. Kuusisto, N.G. Granin, T.D. Prowse, K.M. Stewart and V.S. Vuglinski, 2000. Ice cover phenologies of lakes and rivers in the Northern Hemisphere and climate warming. Science, 289(5485):1743–1746.
  24. ↑ Magnuson, J.J., D.M. Robertson, R.H. Wynne, B.J. Benson, D.M. Livingstone, T. Arai, R. A. Assel, R.D. Barry, V. Card, E. Kuusisto, N.G. Granin, T.D. Prowse, K.M. Stewart and V.S. Vuglinski, 2000. Ice cover phenologies of lakes and rivers in the Northern Hemisphere and climate warming. Science, 289(5485):1743–1746.
  25. ↑ Magnuson, J.J., D.M. Robertson, R.H. Wynne, B.J. Benson, D.M. Livingstone, T. Arai, R. A. Assel, R.D. Barry, V. Card, E. Kuusisto, N.G. Granin, T.D. Prowse, K.M. Stewart and V.S. Vuglinski, 2000. Ice cover phenologies of lakes and rivers in the Northern Hemisphere and climate warming. Science, 289(5485):1743–1746.
  26. ↑ Magnuson, J.J., D.M. Robertson, R.H. Wynne, B.J. Benson, D.M. Livingstone, T. Arai, R. A. Assel, R.D. Barry, V. Card, E. Kuusisto, N.G. Granin, T.D. Prowse, K.M. Stewart and V.S. Vuglinski, 2000. Ice cover phenologies of lakes and rivers in the Northern Hemisphere and climate warming. Science, 289(5485):1743–1746.
  27. ↑ Ginzburg, B.M., K.N. Polyakova and I.I. Soldatova, 1992. Secular changes in dates of ice formation on rivers and their relationship with climate change. Soviet Meteorology and Hydrology, 12:57–64.
  28. ↑ Soldatova, I.I., 1993. Secular variations in river break-up dates and their relationship with climate variation. Russian Meteorology and Hydrology, 9:70–76.
  29. ↑ Ginzburg, B.M., K.N. Polyakova and I.I. Soldatova, 1992. Secular changes in dates of ice formation on rivers and their relationship with climate change. Soviet Meteorology and Hydrology, 12:57–64.
  30. ↑ Soldatova, I.I., 1993. Secular variations in river break-up dates and their relationship with climate variation. Russian Meteorology and Hydrology, 9:70–76.
  31. ↑ Kuusisto, E. and A.-R. Elo, 2000. Lake and river ice variables as climate indicators in Northern Europe. Internationale Vereinigung fur Theoretische und Angewandte Limnologie: Verhandlungen, 27:2761–2764.
  32. ↑ Kuusisto, E. and A.-R. Elo, 2000. Lake and river ice variables as climate indicators in Northern Europe. Internationale Vereinigung fur Theoretische und Angewandte Limnologie: Verhandlungen, 27:2761–2764.–Zachrisson, G., 1989. Climate variation and ice conditions in the River Torneälven. In: Proceedings of the Conference on Climate and Water, Helsinki. Publications of the Academy of Finland, Vol. 1:353–364.
  33. ↑ Chapman, W., 2003. University of Illinois.
  34. ↑ National Snow and Ice Data Center, 2003. Boulder, Colorado.
  35. ↑ Sagarin, R. and F. Micheli, 2001. Climate change in nontraditional data sets. Science, 294:811.
  36. ↑ Jasek, M.J., 1998. 1998 break-up and flood on the Yukon River at Dawson – Did El Niño and climate play a role? In: Proceedings of the Fourteenth International Ice Symposium, Potsdam, New York Vol. 2, pp. 761–768.
  37. ↑ Zhang, X., K.D. Harvey, W.D. Hogg and T.R.Yuzyk, 2001. Trends in Canadian streamflow. Water Resources Research, 37:987–998.
  38. ↑ Smith, L.C., 2000. Trends in Russian Arctic river-ice formation and breakup, 1917–1994. Physical Geography, 21:46–56.
  39. ↑ Ginzburg, B.M., K.N. Polyakova and I.I. Soldatova, 1992. Secular changes in dates of ice formation on rivers and their relationship with climate change. Soviet Meteorology and Hydrology, 12:57–64.
  40. ↑ Soldatova, I.I., 1993. Secular variations in river break-up dates and their relationship with climate variation. Russian Meteorology and Hydrology, 9:70–76.
  41. ↑ Smith, L.C., 2000. Trends in Russian Arctic river-ice formation and breakup, 1917–1994. Physical Geography, 21:46–56.
  42. ↑ Gray, D.M. and T.D. Prowse, 1993. Snow and floating ice. In: D. Maidment (ed.). Handbook of Hydrology, pp. 7.1–7.58. McGraw-Hill.
  43. ↑ Livingstone, D.M., 1999. Ice break-up on southern Lake Baikal and its relationship to local and regional air temperatures in Siberia and to the North Atlantic Oscillation. Limnology and Oceanography, 44:1486–1497.
  44. ↑ Bonsal, B.R. and T.D. Prowse, 2003. Trends and variability in spring and autumn 0°C-isotherm dates over Canada. Climatic Change, 57: 342–358.
  45. ↑ Vavrus, S.J., R.H. Wynne and J. A. Foley, 1996. Measuring the sensitivity of southern Wisconsin lake ice to climate variations and lake depth using a numerical model. Limnology and Oceanography, 41:822–831.
  46. ↑ Prowse, T.D. and S. Beltaos, 2002. Climatic control of river-ice hydrology: a review. Hydrological Processes, 16(4):805–822.
  47. ↑ Duguay, C.R., G.M. Flato, M.O. Jeffries, P. Menard, K. Morris and W.R. Rouse, 2003. Ice-cover variability on shallow lakes at high latitudes: model simulations and observations. Hydrological Processes, 17:3465–3483.
  48. ↑ Petryk, S., 1995. Numerical modeling. In: S. Beltaos (ed.). River Ice Jams, pp. 147–172. Water Resources Publications, Colorado.
Retrieved from "https://editors.eol.org/eoearth/index.php?title=River_and_lake_ice_in_the_Arctic&oldid=137879"