Freshwater discharge in the Arctic

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Published: February 8, 2010, 7:53 pm
Updated: May 7, 2012, 1:14 pm
Author: International Arctic Science Committee
Topic Editor: Sjaak Slanina
Topics:
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This is Section 6.8 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 (6.8.1)

Many of the linkages between the arctic system and global climate involve the hydrological cycle. Theoretical arguments and models both suggest that net high-latitude precipitation increases in proportion to increases in mean hemispheric temperature[1]. Section 6.2.3 (Freshwater discharge in the Arctic) showed that precipitation and precipitation minus evapotranspiration (P-E) are projected to increase in the Arctic as greenhouse gas (GHG) concentrations increase. This is supported by the nearly linear relationship between temperature and ice accumulation found in Greenland ice cores over the past 20,000 years[2]. At the same time, increased freshwater export from the Arctic Ocean may reduce North Atlantic Deep Water formation and Atlantic thermohaline circulation[3]. These changes in Atlantic thermohaline circulation may trigger major climatic shifts. Terrestrial discharge, or river runoff, to the Arctic Ocean may therefore have global implications.

Fig. 6.33. The Arctic

To analyze the variability of the Arctic Ocean’s freshwater budget, both the Arctic Ocean watershed and the adjacent territories from which the runoff originates (Fig. 6.33) must be considered. The total area of the Arctic Ocean drainage basin, together with the adjacent Hudson Bay and Bering Sea drainage basins, is about 24 million square-kilometers (km2)[4]. This huge area includes a wide variety of surface types and climate zones, from semi-arid regions in the south to polar deserts in the north.

The spatial distribution of the hydrological monitoring network in the Arctic is extremely uneven. The greatest numbers of stations are located in Europe, the southern part of western Siberia, and the Hudson Bay drainage basin, while the northern part of the Arctic, including Greenland, the arctic islands, and coastal regions, is essentially unmonitored. Monitoring capacity in both North America and Eurasia peaked in 1985, when the percentage of Arctic Ocean drainage area monitored by gauges was 50.2% in North America, 85.1% in Asia, and 70.7% in Europe (but 0% in Greenland). Since 1985, the number of hydrometric stations has decreased significantly, owing to budget constraints and (in Siberia) population losses. The total number of gauges throughout the Arctic is now 38% lower than in 1985 (Fig. 6.34); in 1999, the discharge monitoring network had the same number of gauges as in 1960[5].

320px-Figure6.34 time series discharge gauges.JPG Fig. 6.34. Time series of the number of river discharge gauges in the Arctic Ocean drainage basin, the Russian Arctic, and the North American Arctic. Shaded area represents the number of stations with data that have been included in the R-ArcticNET database of the Arctic-RIMS project[6].

The total freshwater discharge from the land area into the Arctic Ocean is the sum of river discharge into the ocean, glacier and ice sheet discharge, subsurface water flows (mainly from the freeze–thaw cycle in the active layer of permafrost soils), and groundwater flows. Most of the glacier streamflow enters the subpolar seas (e.g., Greenland Sea, Baffin Bay/Davis Strait, Gulf of Alaska) rather than the Arctic Ocean. Subsurface and groundwater flow to the Arctic Ocean is considered to be orders of magnitude lower than river discharge[7], but is very important during winter, when other sources of discharge are substantially reduced. Seasonally frozen ground also affects the interactions between surface runoff, subsurface runoff, and subsurface storage[8].

Estimates of river discharge to the Arctic Ocean are highly dependent on the specification of the contributing area[9]. According to a contemporary assessment based on available hydrometric and meteorological information[10], the total long-term river discharge from the entire Arctic Ocean drainage basin (including Hudson Bay but not Bering Strait) is 5,250 cubic-kilometers per year (km3/yr) (46% from Asia, 41% from North America and Greenland, and 13% from Europe). Excluding Hudson Bay, direct river discharge to the Arctic Ocean is 4,320 km3/yr (1,190, 2,430, and 700 km3/yr from North America, Asia, and Europe respectively). Table 6.11 presents statistics of the annual discharge to the Arctic Ocean from the different drainage areas. The World Climate Research Programme[11] provided a similar estimate of freshwater flux from land areas to the Arctic Ocean (4,269 km3/yr with 41% attributed to unmeasured discharge). Earlier estimates of total river discharge to the Arctic Ocean were lower: 3,300 km3/yr[12]; 3,500 km3/yr[13]; and 3,740 km3/yr[14]. These earlier studies underestimated the freshwater discharge to the Arctic Ocean because they did not fully consider the unmonitored discharges from the mainland and/or arctic islands. Shiklomanov I. et al.[15] discussed methods for estimating runoff from unmonitored areas. The total river discharge to the Arctic Ocean (~4,300 km3/yr) is several times the net input of freshwater from P-E over the Arctic Ocean (assuming an average P-E of 10 to 15 centimeters per year (cm/yr) (Section 6.2 (Freshwater discharge in the Arctic)) and an area of about 10 million km2).

Table 6.11. Mean annual discharge of freshwater to the Arctic Ocean for the period 1921 to 2000[16].

Basin

Discharge (km3/yr)

Coefficient of variation

Minimum discharge

Maximum discharge

km3

year

km3

year

Bering Strait

301

0.09

362

1990

259

1999

Hudson Bay and Strait

946

0.09

1,140

1966

733

1989

North America (Arctic Ocean drainage basin only)

1,187

0.09

1,510

1996

990

1953

North America including Hudson Bay basin

2,133

0.07

2,475

1996

1,800

1998

Europe

697

0.08

884

1938

504

1960

Asia (Arctic Ocean drainage basin only)

2,430

0.06

2,890

1974

2,100

1953

Arctic Ocean drainage basin

4,314

0.05

4,870

1974

3,820

1953

Arctic Ocean drainage basin and Hudson Bay basin

5,250

0.04

5,950

1974

4,700

1953

The spatial distribution of runoff across the Arctic is highly heterogeneous. When standardized to units of runoff volume per area of a drainage basin, the smallest values (<10 mm/yr) are found in the prairies of Canada and the steppes of West Siberia. The highest values (>1,000 mm/yr) are found in Norway, Iceland, and the mountain regions of Siberia[17].

Rivers flowing into the Arctic Ocean are characterized by very low winter runoff, high spring flow rates driven by snowmelt, and rain-induced floods in the summer and autumn. The degree of seasonality depends on climate conditions, land cover, permafrost extent, and level of natural and artificial runoff regulation. Snowmelt contributes up to 80% of the annual runoff in regions with a continental climate and continuous permafrost, such as the northern parts of central and eastern Siberia, and contributes about 50% of the annual runoff in northern Europe and northeastern Canada[18]. Most eastern Siberian and northern Canadian rivers with drainage areas smaller than 105 km2 that flow through the continuous permafrost zone have practically no runoff during winter because the supply of groundwater is so low.

Recent and ongoing changes (6.8.2)

320px-Figure6.35 time series river discharge.JPG Fig. 6.35. Time series of river discharge to the Arctic Ocean from different parts of the drainage basin between 1921 and 1999[19].

Shiklomanov I. et al.[20] calculated time series of river discharge to the Arctic Ocean from the individual drainage areas between 1921 and 1999 based on hydrometeorological observations. Figure 6.35 summarizes the temporal variations by region. Cyclical discharge variations with relatively small positive trends are evident for the Asian and Northern American regions, while river discharge to Hudson Bay decreased by 6% over the period. According to this assessment, annual freshwater discharge to the Arctic Ocean increased by 112 km3 between 1921 and 1999.

In a study that used long-term hydrometric observations for the Eurasian Arctic, Peterson et al.[21] found that the annual discharge to the Arctic Ocean from the six largest Eurasian [[river]s] increased by 7% between 1936 and 1999. Although the increase is not monotonic (Fig. 6.36), it is statistically significant. The 7% increase in the discharge of these rivers implies that the annual freshwater inflow to the Arctic Ocean is now 128 km3 greater than it was in the mid-1930s.

Variations in river discharge occur primarily in response to variations in atmospheric forcing, particularly air temperature and precipitation. The ten largest arctic river basins all show an increase in air temperature during the past 30 years[22], as shown in Table 6.12. The greatest runoff increase is observed in the large European rivers (e.g., Severnaya Dvina, Pechora), where significant increases in precipitation have occurred. The largest Siberian river basins (e.g., the Yenisey and Lena), in which permafrost is widespread, show an increase in runoff despite a decreasing trend in precipitation. Factors that may have contributed to this increase include a shorter winter period, faster spring snowmelt (reducing evaporation and infiltration losses), thawing permafrost, and saturated soils resulting from an increase in groundwater storage. However, there are large uncertainties in the precipitation data and the calculated changes in precipitation. The relationship between changes in precipitation and river discharge clearly requires additional investigation.

Table 6.12. Changes in air temperature, precipitation, and runoff in the largest arctic river basins between 1936 and 1996, computed based on a linear trend(compiled by A. Shiklomanov using data from New et al.[23])

Period

Change for the period

Permafrost extent (% of total area)

Air temperature (°C)

Precipitation (mm/yr)

River runoffa (mm/yr)

Severnaya Dvina

1936–1996

0.3

24

37

0

1966–1996

1.3

62

44

Pechora

1936–1996

0.5

60

53

31

1966–1996

1.7

27

30

Ob

1936–1996

1.2

3.8

6

19

1966–1996

2.2

-4

1

Yenisey

1936–1996

1.2

-11

13

71

1966–1996

2.5

0

27

Lena

1936–1996

1.1

-5

22

94

1966–1996

2.1

-24

10

Indigirka

1936–1996

0.0

-34

17

100

1966–1996

1.0

-42

1

Kolyma

1936–1996

0.0

-29

-5

100

1966–1996

0.6

-36

15

Yukon

1957–1996

1.6

19

6

90

1966–1996

2.2

43

13

Mackenzie Back

1966–1996

1.4

-6

-5

55

1966–1996

1.7

6

6

100

aChange in river runoff is presented as the net change (mm/yr) in precipitation minus evapotranspiration, which is equivalent to total basin runoff (km3/yr) divided by the area (km2) of the drainage basin.

320px-Figure6.36 eurasian arctic discharge anomaly.JPG Fig. 6.36. Ten-year running averages of the Eurasian Arctic river discharge anomaly (departure from the 1936–1999 mean), global mean surface air temperature (SAT), and the winter (Dec–Mar) NAO index[24].

In addition to its correlation with regional temperature, discharge from the large Siberian [[river]s] is correlated with global mean surface air temperature and with the NAO index[25], as shown in Fig. 6.36. The linkage between the NAO (or its broader manifestation, the AO) and Eurasian temperature and precipitation has been documented by Thompson and Wallace[26] and Dickson et al.[27]. The strengthened westerlies characteristic of the positive phase of the NAO enhance the transport of moisture and relative warmth across northern Europe and northern Asia[28]. It is apparent from Fig. 6.36 that the NAO (or the AO) should be considered in diagnoses of variations in Eurasian river discharge over interannual to decadal timescales.

Savelieva et al.[29] related changes in the seasonality of Siberian river discharge in the second half of the 20th century to a climate shift that occurred in the 1970s. A shift in climatic conditions over the Pacific Ocean and Siberia around 1977 has been well-documented[30].

320px-Figure6.37 deviations of runoff.JPG Fig. 6.37. Deviations of the 1978–2000 mean (a) spring, (b) summer–autumn, (c) winter, and (d) annual runoff expressed as a percentage of the long-term mean for each location and season. Red and blue circles denote positive and negative deviations, respectively. The long-term mean is calculated using the entire gauge station history (at least 50 years for all plotted locations). Stations with no deviation in a specific period are not shown. Tan, orange, and brown indicate progressively higher elevations; green indicates low elevations[31].

When analyzing seasonal trends in river discharge, the downstream gauges of most of the large rivers cannot be used because of the impoundments within their basins. Even small reservoirs can have a significant impact during times of low flow (winter). For example, Ye B. et al.[32] showed that a relatively small reservoir in the Lena Basin significantly changed the winter discharge regime at downstream locations. Therefore, in a recent attempt to identify seasonal variations and changes in the hydrological regime of the Eurasian Arctic, Georgievsky et al.[33] analyzed data from 97 rivers with monthly discharge records exceeding 50 years and no significant human influence. The results show that between 1978 and 2000, winter river runoff increased relative to its longer-term mean across most of the region (Fig. 6.37c). Significant increases (10 to 30%) in winter and summer–autumn runoff occurred in rivers located in the part of European Russia that drains into the Arctic Ocean (Fig. 6.37b, c). Even greater changes occurred in Siberia. Winter runoff increased by up to 40 to 60% in the Irtysh Basin and in southeastern Siberia, and by up to 15 to 35% in northern Siberia.

Figure 6.37d shows that the annual runoff in the Eurasian part of the arctic drainage basin has been significantly higher during the last 20 to 25 years, excluding south-central Siberia where annual runoff has been lower than the longer-term average. The most significant increase (>30%) has occurred in European Russia and the western part of the Irtysh Basin. The runoff in the Lena Basin has increased by up to 15 to 25% in the south and by 5 to 15% in the north.

Projected changes (6.8.3)

General conclusions about the influence of projected climate change on river discharge to the Arctic Ocean are drawn from a synthesis of studies by various investigators from different countries[34]. Climate change scenarios used in all of these estimates were generated by various general circulation models (GCMs) forced with doubled atmospheric CO2 concentrations, with transient increases of CO2, and/or with other forcing from paleoclimatic reconstructions. The climate scenarios generated by the GCMs have been used to force hydrological models of varying complexity[35]. The projections obtained with this approach go beyond the projections of changes in P-E ([[Section 6.2.3 (Freshwater discharge in the Arctic)]2]), since they include the effects of changing temperature and changes in the atmospheric circulation (winds) projected by the GCMs. The projections are summarized in Table 6.13.

Miller and Russell[36] performed one of the first such assessments, using scenarios for doubled atmospheric CO2 concentrations from the Goddard Institute for Space Studies (GISS) and Canadian GCMs as input to a simple water-budget model. This assessment projected increases of 10 to 45% in the discharges of the large Eurasian and North American [[river]s] (Table 6.13).

Shiklomanov A.[37] projected the impact of climate change on the annual and seasonal discharges of the rivers in the Yenisey drainage basin using a number of GCM scenarios and paleoclimate reconstructions as input to the detailed hydrological model developed by the State Hydrological Institute (Russia) (Table 6.13). According to the more plausible climate scenarios, the mean annual discharge of the Yenisey River is likely to increase by 15 to 20%, and the winter discharge is likely to increase by 50 to 60%. Similar evaluations of river discharge to the Barents Sea drainage basin[38] project increases of 14 to 35% and 25 to 46% in the mean annual and winter discharge, respectively (Table 6.13).

Arnell[39] used six GCM scenarios developed by the Hadley Centre to project changes in runoff from the world’s largest rivers between 1961–1990 and 2050. This study projected discharge increases ranging from 3–10% to 30–40% for the largest rivers in the Arctic Ocean drainage basin (Table 6.13). Other assessments[40] also project significant increases in both the discharge of the largest rivers and in the total river discharge to the Arctic Ocean. Georgievsky et al.[41] provided projections for the Lena Basin based on a water balance model with a three-layer environment (the active soil layer and two layers of groundwater reservoirs) using input from the HadCM3 model forced with the A2 emissions scenario (Section 4.4.1 (Freshwater discharge in the Arctic)). Annual runoff is projected to increase by 27 millimeters (mm) (12.5%), with higher percentage increases in winter and spring runoff, which would increase the probability of extreme flooding.

The results presented above indicate that, if atmospheric CO2 concentrations double and the model projections of runoff changes are correct, the total annual discharge to the Arctic Ocean from arctic land areas can be expected to increase by 10 to 20%. The increase in winter discharge is likely to be as high as 50 to 80%. At the same time, 55 to 60% of annual discharge is likely to enter the ocean during the peak runoff season (April–July). It must be emphasized, however, that the B2 emissions scenario ([[Section 4.4.1 (Freshwater discharge in the Arctic)]2]) used to force the ACIA-designated models does not lead to a doubling of CO2 concentrations during the 21st century. Relative to the atmospheric CO2 concentration in 2000 (~370 ppm), the CO2 concentrations in the B2 emissions scenario increase by about 30% by 2050 and 65% by 2100. (In the A2 emissions scenario, the corresponding increases are about 40% by 2050 and 120% by 2100.)

For this reason, it is not surprising that the 10 to 20% increase in discharge cited above is larger than the ACIA-designated model projections of increases in precipitation and P-E, which are about 10% or slightly less (Fig. 6.2). The projected changes in temperature, precipitation, and river discharge obtained from other forcing scenarios (e.g., Table 6.13) must be tempered accordingly.


Table 6.13. Projected change in the discharge of the largest arctic rivers using different climate models and forcing scenarios.

GCM and forcing scenario

Discharge change (%)

Reference

Annual discharge

Winter discharge

Yenisey, Lena, Ob, Kolyma

Canadiana, GISSb 2xCO2

10–45

[42]

Yenisey

SHIc 1°C

9

34

[43]

SHIc 2°C

9

61

SHIc 4°C

15

325

GFDLd 2xCO2

19

70

UKMOe 2xCO2

45

80

Inflow into the Barents Sea

GFDLd 2xCO2; UKMOe 2xCO2

14–35

25–46

[44]

Yenisey

HadCM2f; HadCM3f; 6 scenarios by 2050

6–14

[45]

Lena

12–25

Ob

3–10

Kolyma

30–40

Mackenzie

12–20

Yukon

20–30

Arctic total

GISSb
CO2: +0.5%/yr to 2100

12

[46]

Eurasian rivers

9

North American rivers

23

Lena

HadCM3f 2xCO2

12

[47]

Yenisey

HadCM3f 2xCO2

8

[48]

Lena

24

Ob

4

Yenisey

ECHAM4/OPYC3g 2xCO2

8

[49]

Lena

22

Ob

3

Yenisey

CGCa 2xCO2

18

[50]

Lena

19

Ob

-12

Mackenzie

20

Yukon

10

Usa (Pechora basin)

HadCM2f (2080)

-16

[51]

HadCM2f (2230)

10

aCanadian Centre for Climate Modelling and Analysis; bGoddard Institute for Space Studies (United States); cState Hydrological Institute (Russia); dGeophysical Fluid Dynamics Laboratory (United States); eUnited Kingdom Met Office; fHadley Centre (United Kingdom); gMax-Planck Institute for Meteorology (Germany).

Impacts of projected changes (6.8.4)

On other parts of physical system

Changes in freshwater runoff are likely to affect upper-ocean salinity, sea-ice production, export of freshwater to the North Atlantic subpolar seas, and possibly the thermohaline circulation. In particular, Steele and Boyd[52] have argued that recent changes in the upper layers of the Arctic Ocean are attributable to altered pathways of Siberian river runoff in the Arctic Ocean.

On ecosystems

Changes in extreme runoff events (floods) are likely to alter biological production and biodiversity in riparian systems (Section 8.4 (Freshwater discharge in the Arctic)). The area of ponds and wetlands, for which water levels are critical, can determine whether vast northern peatlands will become sources or sinks of CO2 and CH4 (Section 7.5.3 (Freshwater discharge in the Arctic)). Changes in the fluxes of water and hence nutrients to and from ponds and wetlands will affect aquatic ecology ([[Section 8.4 (Freshwater discharge in the Arctic)]2]).

On people

Traditional lifestyles are likely to be affected by changes in recharging of ponds and wetlands. Navigability of arctic [[river]s] will be affected if runoff levels change substantially, especially during the warm season. Increases in the frequency and magnitude of extreme discharge events will result in catastrophic floods and are likely to require revisions of current construction requirements (Section 16.4 (Freshwater discharge in the Arctic)). Changes in the thickness and/or duration of freshwater ice cover will affect transportation in northern regions (i.e., ice roads) and will influence expanding development (e.g., oil and gas, diamond, and gold exploration).

Critical research needs (6.8.5)

Perhaps the most critical need pertaining to surface flows in the Arctic concerns the network of gauge stations for monitoring discharge rates. This network has degraded seriously in the past decade, such that present measurements of surface flows in the Arctic are much less complete than in the recent past. Many of the monitoring station closures have occurred in Russia and Canada, and to a lesser extent in Alaska. It is important to reopen some of these stations or otherwise enhance the current monitoring network.

Better estimation of subsurface flows is also required. If permafrost thaws in regions of significant discharge to the Arctic Ocean, a quantitative understanding of subsurface flows will become increasingly essential for closing the arctic hydrological budget. A related need is an improved understanding of the relationship between net atmospheric moisture input (P-E), river discharge, and changes in permafrost. Recent findings by Serreze et al.[53] and Savelieva et al.[54] suggested that changes in permafrost may be affecting the linkage between precipitation and river discharge, in terms of the relationships between the water-year means of the two quantities and between the seasonality of the two quantities.

Chapter 6: Cryosphere and Hydrology

6.1. Introduction (Freshwater discharge 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). Freshwater discharge in the Arctic. Retrieved from http://editors.eol.org/eoearth/wiki/Freshwater_discharge_in_the_Arctic
  1. ↑ Manabe, S. and R.J. Stouffer, 1993. Century-scale effects of increased atmospheric CO2 on the ocean-atmosphere system. Nature, 364(6434):215–218.–Rahmstorf, S. and A. Ganopolski, 1999. Long-term global warming scenarios computed with an efficient coupled climate model. Climatic Change, 43:353–367.
  2. ↑ Van der Veen, C.J., 2002. Polar ice sheets and global sea level: how well can we predict the future? Global and Planetary Change, 32:165–194.
  3. ↑ Broecker, W.S., 1997. Thermohaline circulation, the Achilles heel of our climate system: will man-made CO2 upset the current balance? Science, 278:1582–1588.
  4. ↑ Forman, S.L., W. Maslowski, J. T. Andrews, D. Lubinski, M. Steele, J. Zhang, R.B. Lammers and B.J. Peterson, 2000. Researchers explore arctic freshwater?s role in ocean circulation. Eos, Transactions, American Geophysical Union, 81(16):169–174.–Shiklomanov, I. A., A.I. Shiklomanov, R.B. Lammers, B.J. Peterson and C.J. Vorosmarty, 2000. The dynamics of river water inflow to the Arctic Ocean. In: E.L. Lewis, E.P. Jones, P. Lemke, T.D. Prowse and P. Wadhams (eds.). The Freshwater Budget of the Arctic Ocean, pp. 281–296. Kluwer Academic Publishers.
  5. ↑ Shiklomanov, A.I., R.B. Lammers and C.J. Vorosmarty, 2002. Widespread decline in hydrological monitoring threatens pan-Arctic research. Eos, Transactions, American Geophysical Union, 83(2):13,16,17.
  6. ↑ Shiklomanov, A.I., R.B. Lammers and C.J. Vorosmarty, 2002. Widespread decline in hydrological monitoring threatens pan-Arctic research. Eos, Transactions, American Geophysical Union, 83(2):13,16,17.
  7. ↑ Grabs, W.E., F. Portmann and T. de Couet, 2000. Discharge observation networks in Arctic regions: Computations of the river runoff into the Arctic Ocean, its seasonality and variability. In: E.L. Lewis, E.P. Jones, P. Lemke, T.D. Prowse and P. Wadhams (eds.). The Freshwater Budget of the Arctic Ocean, NATO Science Series, pp. 249–268. Kluwer Academic Publishers.
  8. ↑ Bowling, L.C., D.P. Lettenmaer and B.N. Matheussen, 2000. Hydroclimatology of the Arctic Drainage Basin. In: E.L. Lewis, E.P. Jones, P. Lemke, T.D. Prowse and P. Wadhams (eds.). The Freshwater Budget of the Arctic Ocean, pp. 47–90. NATO Meeting/NATO ASI Series, Kluwer Academic Publishers.
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  10. ↑ Shiklomanov, I. A., A.I. Shiklomanov, R.B. Lammers, B.J. Peterson and C.J. Vorosmarty, 2000. The dynamics of river water inflow to the Arctic Ocean. In: E.L. Lewis, E.P. Jones, P. Lemke, T.D. Prowse and P. Wadhams (eds.). The Freshwater Budget of the Arctic Ocean, pp. 281–296. Kluwer Academic Publishers.
  11. ↑ WCRP, 1996. Proceedings of the workshop on the Implementation of the Arctic Precipitation Data Archive (APDA) at the Global Precipitation Climate Centre (GPCC), Offenbach, Germany. World Climate Research Programme. Report No. WCRP-98, 44pp.
  12. ↑ Aagaard, K. and E.C. Carmack, 1989. The role of sea ice and other freshwater in the Arctic circulation. Journal of Geophysical Research, 94:14485–14498.
  13. ↑ Ivanov, V. V., 1976. Fresh water balance of the Arctic Ocean. Proceedings of the Arctic and Antarctic Research Institute, 323:138–147.
  14. ↑ Gordeev, V. V., J.M. Martin, I.S. Sidorov and M. V. Sidorova, 1996. A reassessment of the Eurasian river input of water, sediment, major elements, and nutrients to the Arctic Ocean. American Journal of Science, 296:664–691.
  15. ↑ Shiklomanov, I. A., A.I. Shiklomanov, R.B. Lammers, B.J. Peterson and C.J. Vorosmarty, 2000. The dynamics of river water inflow to the Arctic Ocean. In: E.L. Lewis, E.P. Jones, P. Lemke, T.D. Prowse and P. Wadhams (eds.). The Freshwater Budget of the Arctic Ocean, pp. 281–296. Kluwer Academic Publishers.
  16. ↑ Shiklomanov, I. A., A.I. Shiklomanov, R.B. Lammers, B.J. Peterson and C.J. Vorosmarty, 2000. The dynamics of river water inflow to the Arctic Ocean. In: E.L. Lewis, E.P. Jones, P. Lemke, T.D. Prowse and P. Wadhams (eds.). The Freshwater Budget of the Arctic Ocean, pp. 281–296. Kluwer Academic Publishers.
  17. ↑ Lammers, R.B., A.I. Shiklomanov, C.J. Vorosmarty, B.M. Fekete and B.J. Peterson, 2001. Assessment of contemporary arctic river runoff based on observation discharge records. Journal of Geophysical Research, 106(D4):3321–3334.
  18. ↑ AARI, 1985. Arctic Atlas. Arctic and Antarctic Research Institute, Moscow, 204pp. (In Russian)
  19. ↑ Shiklomanov, I. A., A.I. Shiklomanov, R.B. Lammers, B.J. Peterson and C.J. Vorosmarty, 2000. The dynamics of river water inflow to the Arctic Ocean. In: E.L. Lewis, E.P. Jones, P. Lemke, T.D. Prowse and P. Wadhams (eds.). The Freshwater Budget of the Arctic Ocean, pp. 281–296. Kluwer Academic Publishers.
  20. ↑ Shiklomanov, I. A., A.I. Shiklomanov, R.B. Lammers, B.J. Peterson and C.J. Vorosmarty, 2000. The dynamics of river water inflow to the Arctic Ocean. In: E.L. Lewis, E.P. Jones, P. Lemke, T.D. Prowse and P. Wadhams (eds.). The Freshwater Budget of the Arctic Ocean, pp. 281–296. Kluwer Academic Publishers.
  21. ↑ Peterson, S.J. Prinsenberg, D. Frobel, T.L. Lynds and T.L. Webster, 2002. Discrimination of nearshore, shoreface and estuarine ice on the north shore of Prince Edward Island, Canada, using Radarsat-1 and airborne polarimetric c-band SAR. In: Proceedings of the Seventh International Conference on Remote Sensing for Marine and Coastal Environments. Miami, Florida. 20–22 May 2002. Document 0043, 7pp.
  22. ↑ New, M., M. Hulme and P. Jones, 2000. Representing twentieth-century space-time climate variability. Part II: Development of 1901–96 monthly grids of terrestrial surface climate. Journal of Climate, 13:2217–2238.
  23. ↑ New, M., M. Hulme and P. Jones, 2000. Representing twentieth-century space-time climate variability. Part II: Development of 1901–96 monthly grids of terrestrial surface climate. Journal of Climate, 13:2217–2238.
  24. ↑ Peterson, B.J., R.M. Holmes, J. W. McClelland, C.J. Vorosmarty, R.B. Lammers, A.I. Shiklomanov, I. A. Shiklomanov and S. Rahmstorf, 2002. Increasing river discharge to the Arctic Ocean. Science, 298:2171–2173.
  25. ↑ Peterson, S.J. Prinsenberg, D. Frobel, T.L. Lynds and T.L. Webster, 2002. Discrimination of nearshore, shoreface and estuarine ice on the north shore of Prince Edward Island, Canada, using Radarsat-1 and airborne polarimetric c-band SAR. In: Proceedings of the Seventh International Conference on Remote Sensing for Marine and Coastal Environments. Miami, Florida. 20–22 May 2002. Document 0043, 7pp.
  26. ↑ Thompson, D. W. and J.M. Wallace, 1998. The Arctic Oscillation signature in the wintertime geopotential height and temperature fields. Geophysical Research Letters, 25:1297–1230.
  27. ↑ Dickson, R.R., T.J. Osborn, J. W. Hurrell, J. Meincke, J. Blindheim, B. Adlandsvik, T. Vinje, G. Alekseev and W. Maslowski, 2000. The Arctic Ocean response to the North Atlantic Oscillation. Journal of Climate, 13:2671–2696.
  28. ↑ Semiletov, I.P., N.I. Savelieva and G.E. Weller, 2002. Cause and effect linkages between atmosphere, the Siberian rivers and conditions in the Russian shelf seas. In: I.P. Semiletov (ed.). Changes in the Atmosphere-Land-Sea System in the American Arctic. Proceedings of the Arctic Regional Center, Vladivostok, 3:63–97.
  29. ↑ Savelieva, N.I., I.P. Semiletov, L.N. Vasilevskaya and S.P. Pugach, 2000. A climate shift in seasonal values of meteorological and hydrological parameters for Northeastern Asia. Progress in Oceanography, 47:279–297.
  30. ↑ Hare, S.R. and N.J. Mantua, 2000. Empirical evidence for North Pacific regime shifts in 1977 and 1989. Progress in Oceanography, 47(2–4):103–147.–Minobe, S., 2000. Spatio-temporal structure of the pentadecadal variability over the North Pacific. Progress in Oceanography, 47(2–4):381–407.–Overland, J.E., J.M. Adams and M. A. Bond, 1999. Decadal variability of the Aleutian Low and its relation to high latitude circulation. Journal of Climate, 12:1542–1548.
  31. ↑ Georgievsky, V. Yu., I. A. Shiklomanov and A.L. Shalygin, 2002. Longterm Variations in the Runoff over the Russian Territory. Report of the State Hydrological Institute, St. Petersburg, Russia, 85pp.
  32. ↑ Ye, B., D. Yang and D. Kane, 2003. Changes in Lena River streamflow hydrology: Human impacts versus natural variations. Water Resources Research, 39(7), doi:10.1029/2003WR001991.
  33. ↑ Georgievsky, V. Yu., I. A. Shiklomanov and A.L. Shalygin, 2002. Longterm Variations in the Runoff over the Russian Territory. Report of the State Hydrological Institute, St. Petersburg, Russia, 85pp.
  34. ↑ Shiklomanov, A.I., 1994. Influence of anthropogenic changes in global climate on the Yenisey River Runoff. Meteorology and Hydrology, 2:84–93. (In Russian)–Shiklomanov, A.I., 1997. On the effect of anthropogenic change in the global climate on river runoff in the Yenisei basin. In: Runoff Computations for Water Projects. Proceedings of the St. Petersburg Symposium 30 Oct.–03 Nov. 1995, pp. 113–119. IHP-V UNESCO Technical Document in Hydrology N9.–Van der Linden, S., T. Virtanen, N. Oberman and P. Kuhry, 2003. Sensitivity analysis of discharge in the arctic Usa basin, East-European Russia. Climatic Change, 57:139–161.
  35. ↑ Shiklomanov, I. A. and H. Lins, 1991. Effect of climate change on hydrology and water management. Meteorology and Hydrology, 4:51–65. (In Russian)
  36. ↑ Miller, J.R. and G.L. Russell, 1992. The impact of global warming on river runoff. Journal of Geophysical Research, 97(D3):2757–2764.
  37. ↑ Shiklomanov, A.I., 1994. Influence of anthropogenic changes in global climate on the Yenisey River Runoff. Meteorology and Hydrology, 2:84–93. (In Russian)
  38. ↑ Georgievsky, V. Yu., A. V. Ezhov, A.L. Shalygin, I. A. Shiklomanov and A.I. Shiklomanov, 1996. Evaluation of possible climate change impact on hydrological regime and water resources of the former USSR rivers. Meteorology and Hydrology, 11:89–99. (In Russian)
  39. ↑ Arnell, N. W., 1999. Climate change and global water resources. Global Environmental Change, 9:31–49.
  40. ↑ Arora, V.K. and G.J. Boer, 2001. Effects of simulated climate change on the hydrology of major river basins. Journal of Geophysical Research, 106(D4):3335–3348.–Miller, J.R. and G.L. Russell, 2000. Projected impact of climate change on the freshwater and salt budgets of the Arctic Ocean by a global climate model. Geophysical Research Letters, 27:1183–1186.–Mokhov, I.I., V. A. Semenov and V.Ch. Khon, 2003. Estimates of possible regional hydrologic regime changes in the 21st century based on Global Climate Models. Izvestiya, Atmospheric and Oceanic Physics, 39(2):130–144.
  41. ↑ Georgievsky, V. Yu., I. A. Shiklomanov and A.L. Shalygin, 2003. Possible Changes of Water Resources and Water Regimes in the Lena Basin Due to Global Climate Warming. Report of the State Hydrological Institute, St. Petersburg, Russia.
  42. ↑ Miller, J.R. and G.L. Russell, 1992. The impact of global warming on river runoff. Journal of Geophysical Research, 97(D3):2757–2764.
  43. ↑ Shiklomanov, A.I., 1994. Influence of anthropogenic changes in global climate on the Yenisey River Runoff. Meteorology and Hydrology, 2:84–93. (In Russian)–Shiklomanov, A.I., 1997. On the effect of anthropogenic change in the global climate on river runoff in the Yenisei basin. In: Runoff Computations for Water Projects. Proceedings of the St. Petersburg Symposium 30 Oct.–03 Nov. 1995, pp. 113–119. IHP-V UNESCO Technical Document in Hydrology N9.
  44. ↑ Georgievsky, V. Yu., A. V. Ezhov, A.L. Shalygin, I. A. Shiklomanov and A.I. Shiklomanov, 1996. Evaluation of possible climate change impact on hydrological regime and water resources of the former USSR rivers. Meteorology and Hydrology, 11:89–99. (In Russian)
  45. ↑ Arnell, N. W., 1999. Climate change and global water resources. Global Environmental Change, 9:31–49.
  46. ↑ Miller, J.R. and G.L. Russell, 2000. Projected impact of climate change on the freshwater and salt budgets of the Arctic Ocean by a global climate model. Geophysical Research Letters, 27:1183–1186.
  47. ↑ Georgievsky, V. Yu., I. A. Shiklomanov and A.L. Shalygin, 2003. Possible Changes of Water Resources and Water Regimes in the Lena Basin Due to Global Climate Warming. Report of the State Hydrological Institute, St. Petersburg, Russia.
  48. ↑ Mokhov, I.I. and V.Ch. Khon, 2002. Hydrological regime in basins of Siberian rivers: Model estimates of changes in the 21st century. Meteorology and Hydrology, 8:77–92. (In Russian)–Mokhov, I.I., V. A. Semenov and V.Ch. Khon, 2003. Estimates of possible regional hydrologic regime changes in the 21st century based on Global Climate Models. Izvestiya, Atmospheric and Oceanic Physics, 39(2):130–144.
  49. ↑ Mokhov, I.I. and V.Ch. Khon, 2002. Hydrological regime in basins of Siberian rivers: Model estimates of changes in the 21st century. Meteorology and Hydrology, 8:77–92. (In Russian)–Mokhov, I.I., V. A. Semenov and V.Ch. Khon, 2003. Estimates of possible regional hydrologic regime changes in the 21st century based on Global Climate Models. Izvestiya, Atmospheric and Oceanic Physics, 39(2):130–144.
  50. ↑ Arora, V.K. and G.J. Boer, 2001. Effects of simulated climate change on the hydrology of major river basins. Journal of Geophysical Research, 106(D4):3335–3348.
  51. ↑ Van der Linden, S., T. Virtanen, N. Oberman and P. Kuhry, 2003. Sensitivity analysis of discharge in the arctic Usa basin, East-European Russia. Climatic Change, 57:139–161.
  52. ↑ Steele, M. and T. Boyd, 1998. Retreat of the cold halocline layer in the Arctic Ocean. Journal of Geophysical Research, 103:10419–10435.
  53. ↑ Serreze, M.C., D.H. Bromwich, M.P. Clark, A.J. Etringer, T. Zhang and R. Lammers, 2003. Large-scale hydro-climatology of the terrestrial Arctic drainage system. Journal of Geophysical Research, 108(D2). doi:10.1029/2001JD000919.
  54. ↑ Savelieva, N.I., I.P. Semiletov, L.N. Vasilevskaya and S.P. Pugach, 2002. Climatic variability of the Siberian rivers seasonal discharge. In: I.P. Semiletov (ed.). Hydrometeorological and Biogeochemistry Research in the Arctic. Trudy Arctic Regional Center, 2:9–22. (In Russian)
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