Ice cover and thermal regime in a dimictic seepage lake under climate change

Inland Waters ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 381-398 ◽  
Author(s):  
David P. Hamilton ◽  
Madeline R. Magee ◽  
Chin H. Wu ◽  
Timothy K. Kratz
Keyword(s):  
Climate Change ◽  
Thermal Regime ◽  
Ice Cover ◽  
Seepage Lake

Wintertime growth in Atlantic salmon under changing climate: the importance of ice cover for individual growth dynamics

2021 ◽  
Author(s):  
Laura Härkönen ◽  
Pauliina Louhi ◽  
Riina Huusko ◽  
Ari Huusko
Keyword(s):  
Climate Change ◽  
Atlantic Salmon ◽  
Growth Rates ◽  
Growth Dynamics ◽  
Ice Cover ◽  
Individual Growth ◽  
Late Winter ◽  
Dynamic Nature ◽  
Individual Level ◽  
Growth Variation

Understanding the dynamic nature of individual growth in stream-dwelling salmonids may help forecast consequences of climate change on northern fish populations. Here, we performed an experimental capture-mark-recapture study in Atlantic salmon to quantify factors influencing wintertime growth variation among juveniles under different scenarios for ice cover reduction. We applied multiple imputation to simulate missing size observations for unrecaptured fish, and to account for individual-level variation in growth rates. The salmon parr exhibited substantial body length shrinkage in early winter, suppressed growth through mid-winter, and increasing growth rates in late winter and particularly in spring. Unexpectedly, the presence of ice cover had no direct effects on wintertime growth. Instead, our results implied increasing energetic costs with reducing ice cover: individuals exposed to absent or shortened ice-covered period gained mass at a lowered rate in spring whereas the present, long ice-covered period was followed by rapid growth. This study emphasizes natural resilience of Atlantic salmon to wintertime environmental variation which may help the species to cope with the reductions in ice cover duration due to climate change.

Arctic sea ice cover in connection with climate change

2015 ◽  
Vol 51 (9) ◽  
pp. 889-902 ◽  
Author(s):  
G. V. Alekseev ◽  
E. I. Aleksandrov ◽  
N. I. Glok ◽  
N. E. Ivanov ◽  
V. M. Smolyanitsky ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
Arctic Sea

scholarly journals Late-Holocene changes in character and behaviour of land-terminating glaciers on James Ross Island, Antarctica

2012 ◽  
Vol 58 (212) ◽  
pp. 1176-1190 ◽  
Author(s):  
Jonathan L. Carrivick ◽  
Bethan J. Davies ◽  
Neil F. Glasser ◽  
Daniel Nývlt ◽  
Michael J. Hambrey
Keyword(s):  
Climate Change ◽  
Sediment Transport ◽  
Surface Structure ◽  
Antarctic Peninsula ◽  
Thermal Regime ◽  
Late Holocene ◽  
Negative Mass ◽  
Warming Climate ◽  
James Ross Island ◽  
Geometric Changes

AbstractVirtually no information is available on the response of land-terminating Antarctic Peninsula glaciers to climate change on a centennial timescale. This paper analyses the topography, geomorphology and sedimentology of prominent moraines on James Ross Island, Antarctica, to determine geometric changes and to interpret glacier behaviour. The moraines are very likely due to a late-Holocene phase of advance and featured (1) shearing and thrusting within the snout, (2) shearing and deformation of basal sediment, (3) more supraglacial debris than at present and (4) short distances of sediment transport. Retreat of ~100 m and thinning of 15–20 m has produced a loss of 0.1 km3 of ice. The pattern of surface lowering is asymmetric. These geometrical changes are suggested most simply to be due to a net negative mass balance caused by a drier climate. Comparisons of the moraines with the current glaciological surface structure of the glaciers permits speculation of a transition from a polythermal to a cold-based thermal regime. Small land-terminating glaciers in the northern Antarctic Peninsula region could be cooling despite a warming climate.

scholarly journals Early Spawning by the American Brook Lamprey (Lethenteron appendix) in Southeastern Minnesota

2013 ◽  
Vol 126 (3) ◽  
pp. 204 ◽  
Author(s):  
Philip A. Cochran ◽  
Mark A. Ross ◽  
Thomas S. Walker ◽  
Trevor Biederman
Keyword(s):  
Climate Change ◽  
Water Temperature ◽  
Thermal Regime ◽  
Historical Data ◽  
Upper Midwest ◽  
Brook Lamprey ◽  
The Mean

Record-setting warm temperatures in the upper Midwest during early 2012 resulted in early spawning by the American Brook Lamprey (Lethenteron appendix) in southeastern Minnesota. American Brook Lampreys in a total of five streams in three drainages spawned up to one month earlier than typical. Mean day of year of spawning groups observed in 2012 was significantly different from the mean for groups observed during the period 2002–2010, but mean water temperature was not significantly different. Limited historical data are not sufficient to show an effect of climate change on spawning phenology because some data are confounded with the effects of latitude and year-to-year variability in thermal regime.

scholarly journals Thermal Regime of A Deep Temperate Lake and Its Response to Climate Change: Lake Kuttara, Japan

Hydrology ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 17 ◽  
Author(s):  
Kazuhisa A. Chikita ◽  
Hideo Oyagi ◽  
Tadao Aiyama ◽  
Misao Okada ◽  
Hideyuki Sakamoto ◽  
...  
Keyword(s):  
Climate Change ◽  
Thermal Regime ◽  
Temperate Lake

Antarctic marine primary production, biogeochemical carbon cycles and climatic change

1992 ◽  
Vol 338 (1285) ◽  
pp. 289-297 ◽  
Keyword(s):  
Climate Change ◽  
Southern Ocean ◽  
Primary Production ◽  
Climatic Change ◽  
Carbon Fixation ◽  
Algal Growth ◽  
Ice Cover ◽  
Phytoplankton Production ◽  
Numerical Predictions ◽  
Model Predictions

In the Southern Ocean, inorganic macronutrients are very rarely depleted by phytoplankton growth. This has led to speculation on possible additional CO 2 drawdown in this region. However, the effects of climate change can only be predicted once the role of environmental and biotic factors limiting phytoplankton carbon fixation are understood. It is clear that the Southern Ocean is heterogeneous, and no single factor controls prim ary production overall. Ice cover and vertical mixing influence algal growth rates by m odulating radiance flux. Micronutrients, especially iron, may limit growth in some areas. Primary production is also suppressed by high removal rates of algal biomass. Grazing by zooplankton is the major factor determining magnitude and quality of vertical particle flux. Several of the physical controls on phytoplankton production are sensitive to climate change. Although it is impossible to make numerical predictions of future change on the basis of our present knowledge, qualitative assessments can be put forward on the basis of model predictions of climate change and known factors controlling prim ary production. Changes in water temperature and in windinduced mixing are likely to be slight and have little effect. Model predictions of changes in sea-ice cover vary widely, making prediction of biogeochemical effects impossible. Even if climatic change induces increased nutrient uptake, there are several reasons to suspect that carbon sequestration will be ineffective in comparison with continuing anthropogenic CO 2 emission.

River ice breakup processes: recent advances and future directions

2007 ◽  
Vol 34 (6) ◽  
pp. 703-716 ◽  
Author(s):  
Spyros Beltaos
Keyword(s):  
Climate Change ◽  
Effective Means ◽  
Climate Change Impacts ◽  
Ice Cover ◽  
Aquatic Life ◽  
Ice Jams ◽  
Ice Jam ◽  
Ice Breakup ◽  
Extreme Flood ◽  
Mitigation Methods

The breakup of the winter ice cover is a brief but seminal event in the regime of northern rivers, and in the life cycle of river and basin ecosystems. Breakup ice jams can cause extreme flood events, with major impacts on riverside communities, aquatic life, infrastructure, navigation, and hydropower generation. Related concerns are underscored by the issue of climate change and the faster warming that is predicted for northern parts of the globe. Advances in knowledge of breakup processes and related topics, achieved over the past 15 years or so, are outlined. They pertain to breakup initiation and ice-jam formation, ice-jam properties and numerical modelling of ice jams, waves generated by ice-jam releases, forecasting and mitigation methods, sediment transport, ecological aspects, and climate-change impacts. Major knowledge gaps are associated with the dynamic interaction of moving ice with the flow and with the stationary ice cover. Increasing computing capacity and remote sensing sophistication are expected to provide effective means for bridging these gaps. Key words: climate, ecology, forecasting, ice jam, modelling, onset, sediment, wave.

scholarly journals Wave Climate Associated With Changing Water Level and Ice Cover in Lake Michigan

2021 ◽  
Vol 8 ◽  
Author(s):  
Chenfu Huang ◽  
Longhuan Zhu ◽  
Gangfeng Ma ◽  
Guy A. Meadows ◽  
Pengfei Xue
Keyword(s):  
Climate Change ◽  
Water Level ◽  
Lake Michigan ◽  
Linear Trend ◽  
Ice Cover ◽  
Wave Climate ◽  
Water Levels ◽  
Regional Warming ◽  
Model Simulations

Detailed knowledge of wave climate change is essential for understanding coastal geomorphological processes, ecosystem resilience, the design of offshore and coastal engineering structures and aquaculture systems. In Lake Michigan, the in-situ wave observations suitable for long-term analysis are limited to two offshore MetOcean buoys. Since this distribution is inadequate to fully represent spatial patterns of wave climate across the lake, a series of high-resolution SWAN model simulations were performed for the analysis of long-term wave climate change for the entirety of Lake Michigan from 1979 to 2020. Model results were validated against observations from two offshore buoys and 16 coastal buoys. Linear regression analysis of significant wave height (Hs) (mean, 90th percentile, and 99th percentile) across the entire lake using this 42-year simulation suggests that there is no simple linear trend of long-term changes of Hs for the majority (>90%) of the lake. To address the inadequacy of linear trend analysis used in previous studies, a 10-year trailing moving mean was applied to the Hs statistics to remove seasonal and annual variability, focusing on identifying long-term wave climate change. Model results reveal the regime shifts of Hs that correspond to long-term lake water level changes. Specifically, downward trends of Hs were found in the decade of 1990–2000; low Hs during 2000–2010 coincident with low lake levels; and upward trends of Hs were found during 2010–2020 along with rising water levels. The coherent pattern between the wave climate and the water level was hypothesized to result from changing storm frequency and intensity crossing the lake basin, which influences both waves (instantly through increased wind stress on the surface) and water levels (following, with a lag through precipitation and runoff). Hence, recent water level increases and wave growth were likely associated with increased storminess observed in the Great Lakes. With regional warming, the decrease in ice cover in Lake Michigan (particularly in the northernmost region of the lake) favored the wave growth in the winter due to increased surface wind stress, wind fetch, and wave transmission. Model simulations suggest that the basin-wide Hs can increase significantly during the winter season with projected regional warming and associated decreases in winter ice cover. The recent increases in wave height and water level, along with warming climate and ice reduction, may yield increasing coastal damages such as accelerating coastal erosion.

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