Terry D. Prowse

Climate change effects on hydroecology of arctic freshwater ecosystems.

Abstract In general, the arctic freshwater-terrestrial system will warm more rapidly than the global average, particularly during the autumn and winter season. The decline or loss of many cryospheric components and a shift from a nival to an increasingly pluvial system will produce numerous physical effects on freshwater ecosystems. Of particular note will be reductions in the dominance of the spring freshet and changes in the intensity of river-ice breakup. Increased evaporation/evapotranspiration due to longer ice-free seasons, higher air/water temperatures and greater transpiring vegetation along with increase infiltration because of permafrost thaw will decrease surface water levels and coverage. Loss of ice and permafrost, increased water temperatures and vegetation shifts will alter water chemistry, the general result being an increase in lotic and lentic productivity. Changes in ice and water flow/levels will lead to regime-specific increases and decreases in habitat availability/quality across the circumpolar Arctic.

Climate Change Effects on Aquatic Biota, Ecosystem Structure and Function

Abstract Climate change is projected to cause significant alterations to aquatic biogeochemical processes, (including carbon dynamics), aquatic food web structure, dynamics and biodiversity, primary and secondary production; and, affect the range, distribution and habitat quality/quantity of aquatic mammals and waterfowl. Projected enhanced permafrost thawing is very likely to increase nutrient, sediment, and carbon loadings to aquatic systems, resulting in both positive and negative effects on freshwater chemistry. Nutrient and carbon enrichment will enhance nutrient cycling and productivity, and alter the generation and consumption of carbon-based trace gases. Consequently, the status of aquatic ecosystems as carbon sinks or sources is very likely to change. Climate change will also very likely affect the biodiversity of freshwater ecosystems across most of the Arctic. The magnitude, extent, and duration of the impacts and responses will be system- and location-dependent. Projected effects on aquatic mammals and waterfowl include altered migration routes and timing; a possible increase in the incidence of mortality and decreased growth and productivity from disease and/or parasites; and, probable changes in habitat suitability and timing of availability.

The freshwater budget of the Arctic Ocean

Preface. Acknowledgements. Summary Poem. Introduction. 1. Oceanic freshwater fluxes in the climate system A. Stigebrandt. 2. Global atmospheric circulation patterns and relationships to Arctic freshwater fluxes J.E. Walsh. 3. Atmospheric components of the Arctic Ocean freshwater balance and their interannual variability R.G. Barry, M.C. Serreze. 4. Hydroclimatology of the Arctic drainage basin L.C. Bowling, P.D. Lettenmaier, B.V. Matheussen. 5. The Arctic Oceans freshwater budget: sources, storage and export E.C. Carmack. 6. The Arctic Ocean freshwater budget of a climate General Circulation Model H. Cattle, D. Cresswell. 7. Atmospheric components of the Arctic Ocean hydrologic budget assessed from Rawinsonde data M.C. Serreze, R.G. Barry. 8. Reanalyses depictions of the Arctic atmospheric moisture budget D.H. Bromwich, R.I. Cullather, M.C. Serreze. 9. Moisture transport to Arctic drainage basins relating to significant precipitation events and cyclogenesis J.R. Gyakum. 10. Atmospheric climate models: simulation of the Arctic Ocean fresh water budget components V.M. Kattsov, J.E. Walsh, A. Rinke, K. Dethloff. 11. Discharge observation networks in Arctic regions: computation of the river runoff into the Arctic Ocean, its seasonality and variability W.E. Grabs, F. Portmann, T. de Couet. 12. Arctic river flow: a review of contributing areas T.D. Prowse, P.O. Flegg. 13. The dynamics of river water inflow to the Arctic Ocean I.A. Shiklomanov, A.I. Shiklomanov, R.B. Lammers, B.J. Peterson, C.J. Vorosmarty. 14. River input of water, sediment, major ions, nutrients and trace metals from Russian territory to the Arctic Ocean V.V. Gordeev. 15. The dispersion of Siberian river flows into coastal waters: meteorological, hydrological and hydrochemical aspects I.P. Semiletov, N.I. Savelieva, G.E. Weller, I.I. Pipko, S.P. Pugach, A.Yu. Gukov, L.N. Vasilevskaya. 16. The variable climate of the Mackenzie River basin: its water cycle and fresh water discharge R.E. Stewart. 17. Arctic estuaries and ice: a positive-negative estuarine couple R.W. Macdonald. 18. Satellite views of the Arctic Ocean freshwater balance D.A. Rothrock, R. Kwok, D. Groves. 19. Tracer studies of the Arctic freshwater budget P. Schlosser, B. Ekwurzel, S. Khatiwala, B. Newton, W. Maslowski, S. Pfirman. 20. Exchanges of freshwater through the shallow straits of the North American Arctic H. Melling. 21. The transformations of Atlantic water in the Arctic Ocean and their significance for the freshwater budget B. Rudels, H.J. Friedrich. 22. Modelling the variability of exchanges between the Arctic Ocean and the Nordic seas R. Gerdes. 23. Sea ice growth, melt and modeling: a survey M. Steele M., G.M. Flato. 24. Fresh water freezing/melting cycle in the Arctic Ocean G.V. Alekseev, L.V. Bulatov, V.F. Zakharov. Subject Index.

General effects of climate change on Arctic fishes and fish populations.

Abstract Projected shifts in climate forcing variables such as temperature and precipitation are of great relevance to arctic freshwater ecosystems and biota. These will result in many direct and indirect effects upon the ecosystems and fish present therein. Shifts projected for fish populations will range from positive to negative in overall effect, differ among species and also among populations within species depending upon their biology and tolerances, and will be integrated by the fish within their local aquascapes. This results in a wide range of future possibilities for arctic freshwater and diadromous fishes. Owing to a dearth of basic knowledge regarding fish biology and habitat interactions in the north, complicated by scaling issues and uncertainty in future climate projections, only qualitative scenarios can be developed in most cases. This limits preparedness to meet challenges of climate change in the Arctic with respect to fish and fisheries.

Arctic system on trajectory to new, seasonally ice‐free state

The Arctic system is moving toward a new state that falls outside the envelope of glacialinterglacial fl uctuations that prevailed during recent Earth history. This future Arctic is likely to have dramatically less permanent ice than exists at present. At the present rate of change, a summer ice-free Arctic Ocean within a century is a real possibility, a state not witnessed for at least a million years. The change appears to be driven largely by feedback-enhanced global climate warming, and there seem to be few, if any, processes or feedbacks within the Arctic system that are capable of altering the trajectory toward this “super interglacial” state.

An Overview of Effects of Climate Change on Selected Arctic Freshwater and Anadromous Fishes

Abstract Arctic freshwater and diadromous fish species will respond to the various effects of climate change in many ways. For wide-ranging species, many of which are key components of northern aquatic ecosystems and fisheries, there is a large range of possible responses due to inter- and intra-specific variation, differences in the effects of climate drivers within ACIA regions, and differences in drivers among regions. All this diversity, coupled with limited understanding of fish responses to climate parameters generally, permits enumeration only of a range of possible responses which are developed here for selected important fishes. Accordingly, in-depth examination is required of possible effects within species within ACIA regions, as well as comparative studies across regions. Two particularly important species (Arctic char and Atlantic salmon) are examined as case studies to provide background for such studies.

Climate impacts on extreme ice-jam events in Canadian rivers

Abstract River ice jams can produce extreme flood events with major social, economic and ecological impacts throughout Canada. Ice breakup and jamming processes are briefly reviewed and shown to be governed by the flow hydrograph, the thickness and strength of the winter ice cover, and the stream morphology. These factors are directly or indirectly influenced by weather conditions which implies potential impacts of climate change and variability on the severity of ice-jamming. Relevant work has to date focused on simple measures of climatic effects, such as the timing of freeze-up and breakup, and indicates trends that are consistent with concomitant changes in air temperature. More recently, it has been found that increased incidence of mid-winter breakup events and higher freshet flows in certain parts of Canada could enhance the frequency and severity of ice jams. Possible future trends under climate warming scenarios are discussed and associated impacts identified in a general manner.

Arctic terrestrial hydrology : A synthesis of processes, regional effects, and research challenges

Terrestrial hydrology is central to the Arctic system and its freshwater circulation. Water transport and water constituents vary, however, across a very diverse geography. In this paper, which is ...

Effects of Changes in Arctic Lake and River Ice

Climatic changes to freshwater ice in the Arctic are projected to produce a variety of effects on hydrologic, ecological, and socio-economic systems. Key hydrologic impacts include changes to low flows, lake evaporation regimes and water levels, and river-ice break-up severity and timing. The latter are of particular concern because of their effect on river geomorphology, vegetation, sediment and nutrient fluxes, and sustainment of riparian aquatic habitats. Changes in ice phenology will affect a wide range of related biological aspects of seasonality. Some changes are likely to be gradual, but others could be more abrupt as systems cross critical ecological thresholds. Transportation and hydroelectric production are two of the socio-economic sectors most vulnerable to change in freshwater-ice regimes. Ice roads will require expensive on-land replacements while hydroelectric operations will both benefit and be challenged. The ability to undertake some traditional harvesting methods will also be affected.

Implications of Climate Change for Economic Development in Northern Canada: Energy, Resource, and Transportation Sectors

Abstract Northern Canada is projected to experience major changes to its climate, which will have major implications for northern economic development. Some of these, such as mining and oil and gas development, have experienced rapid expansion in recent years and are likely to expand further, partly as the result of indirect effects of changing climate. This article reviews how a changing climate will affect several economic sectors including the hydroelectric, oil and gas, and mining industries as well as infrastructure and transportation, both marine and freshwater. Of particular importance to all sectors are projected changes in the cryosphere, which will create both problems and opportunities. Potential adaptation strategies that could be used to minimize the negative impacts created by a climate change are also reviewed.