The effect of water column stability on acoustic backscatter from the ocean bubble layer

1996 ◽  
Vol 100 (4) ◽  
pp. 2806-2806
Author(s):  
Kathy K. Bekker ◽  
Kenneth E. Gilbert ◽  
Ralph R. Goodman
Keyword(s):  
Water Column ◽  
Acoustic Backscatter ◽  
Water Column Stability ◽  
Effect Of Water ◽  
Bubble Layer

scholarly journals Effect of Water Column Stability on Surface Chlorophyll and Time Lags under Different Nutrient Backgrounds in a Deep Reservoir

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1504 ◽  
Author(s):  
Min Zhang ◽  
Zhipan Niu ◽  
Qinghua Cai ◽  
Yaoyang Xu ◽  
Xiaodong Qu
Keyword(s):  
Water Column ◽  
Algal Blooms ◽  
Cyanobacterial Blooms ◽  
Hydrodynamic Process ◽  
Time Lags ◽  
Chl A ◽  
Water Column Stability ◽  
Effect Of Water ◽  
Cross Correlation Analysis ◽  
Short Time

Hydrodynamic conditions are considered to be very important in the control of algal blooms. Weekly or daily measurements may miss some important events in the hydrodynamic process, resulting in inaccurate evaluations of the impacts of hydrodynamics on phytoplankton. In this study, high-frequency (15-min interval) measurements were used to analyze the effect of water column stability on surface chlorophyll a (Chl a) and lag time under different nutrient backgrounds during a cyanobacterial bloom in the Three Gorges Reservoir, China. Cross-correlation analysis between the relative water column stability (RWCS) and Chl a was performed at different stages. The results showed that the RWCS above the euphotic depth influenced the surface Chl a concentration most significantly. A lower RWCS (<20) limited the increase in the Chl a concentration, and a higher RWCS caused a significant increase in Chl a only when nutrients were not limited (TN/TP < 29) and light and temperature conditions were suitable. It took a short time for a higher RWCS to significantly increase the surface Chl a concentration compared with a lower RWCS. When the waterbody had a very low Chl a concentration (almost 0), approximately 2 days were needed to significantly increase the Chl a concentration, while approximately only half an hour was needed when the background concentration of Chl a was slightly higher. During the bloom period, a decline in the RWCS significantly decreased the Chl a in a very short time (approximately half an hour). Reducing the water column stability could be a good approach to control cyanobacterial blooms.

scholarly journals 13 Years of Storms: An Analysis of the Effects of Storms on Lake Physics on the Atlantic Fringe of Europe

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 318 ◽  
Author(s):  
Mikkel René Andersen ◽  
Elvira de Eyto ◽  
Mary Dillane ◽  
Russell Poole ◽  
Eleanor Jennings
Keyword(s):  
Water Column ◽  
Western Europe ◽  
Thermal Structure ◽  
Winter Storms ◽  
Water Column Stability ◽  
Physical Conditions ◽  
Order Of Magnitude ◽  
Storm Frequency ◽  
Summer Storm ◽  
Lake Physics

While winter storms are generally common in western Europe, the rarer summer storms may result in more pronounced impacts on lake physics. Using long-term, high frequency datasets of weather and lake thermal structure from the west of Ireland (2005 to 2017), we quantified the effects of storms on the physical conditions in a monomictic, deep lake close to the Atlantic Ocean. We analysed a total of 227 storms during the stratified (May to September, n = 51) and non-stratified (November to March, n = 176) periods. In winter, as might be expected, changes were distributed over the entire water column, whereas in summer, when the lake was stratified, storms only impacted the smaller volume above the thermocline. During an average summer (May–September) storm, the lake number dropped by an order of magnitude, the thermocline deepened by an average of 2.8 m, water column stability decreased by an average of 60.4 j m−2 and the epilimnion temperature decreased by a factor of five compared to the average change in winter (0.5 °C vs. 0.1 °C). Projected increases in summer storm frequency will have important implications for lake physics and biological pathways.

Relationship of water column stability to the growth, condition, and survival of pink salmon (Oncorhynchus gorbuscha) in the northern coastal Gulf of Alaska and Prince William Sound

2012 ◽  
Vol 69 (5) ◽  
pp. 955-969 ◽  
Author(s):  
Sara E. Miller ◽  
Milo Adkison ◽  
Lewis Haldorson
Keyword(s):  
Water Column ◽  
Growth Condition ◽  
Pink Salmon ◽  
Gulf Of Alaska ◽  
Oncorhynchus Gorbuscha ◽  
Biological Parameters ◽  
Prince William Sound ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Fish Condition ◽  
Water Column Stability

Water column stability has been hypothesized to affect growth and ultimately survival of juvenile fish. We estimated the relationships between stability and the growth, condition, and marine survival of several stocks of pink salmon ( Oncorhynchus gorbuscha ) within Prince William Sound (PWS), Alaska, USA, and the northern coastal Gulf of Alaska (GOA) shelf. There was a stronger correlation among the biological parameters of the fish than between the biological parameters and physical conditions. While stability and fish condition during early marine residence in PWS were important to year-class survival, stability of the water column that juveniles experienced as they migrated to the open waters of the GOA did not play a key role in determining survival to adulthood. Below-average stability just prior to capture within PWS combined with positive fish condition was related to increased year-class survival. Our results are similar to previous studies that concluded that slower and weaker development of stratification with a deeper mixed layer depth may be important for juvenile pink salmon survival in PWS.

scholarly journals CARACTERISTICAS FISICO-QUIMICAS DE LA BAHIA DE SANTA MARTA (AGOSTO 1980 - JULIO 1981)

2016 ◽  
Vol 13 ◽  
Author(s):  
Gustavo Ramírez T.
Keyword(s):  
Surface Water ◽  
Water Column ◽  
Annual Cycle ◽  
Water Column Stability ◽  
Physical Chemical ◽  
Chemical Conditions

Physical-chemical conditions have been studied in the Bay of Santa Marta, Colombian Caribbean, from August 1980 to July 1981. The results obtained at nine stations indicate that the surface water is rather homogeneous and of mainly oceanic character. In the period from december to april water temperatures were lowest (<25®C), salinity highest (>36°/oo) and undersaturation with oxigen occured (<91%) these factors together with pH, alcalinity and the variation of water column stability are indicating an upwelling phenomenon in this period and allow the stablishment of an approximated model for the annual cycle the bay.

scholarly journals Water Column Stability and the Role of Velocity Shear on a Seasonally Stratified Shelf, Mississippi Bight, Northern Gulf of Mexico

2018 ◽  
Vol 123 (8) ◽  
pp. 5777-5796 ◽  
Author(s):  
Brian Dzwonkowski ◽  
Severine Fournier ◽  
Kyeong Park ◽  
Steven L. Dykstra ◽  
John T. Reager
Keyword(s):  
Gulf Of Mexico ◽  
Water Column ◽  
Velocity Shear ◽  
Northern Gulf Of Mexico ◽  
Water Column Stability

scholarly journals Varying water column stability controls the denitrification process in a subtropical reservoir, Southwest China

2022 ◽  
Vol 111 ◽  
pp. 208-219
Author(s):  
Gaoyang Cui ◽  
Xiao-Dong Li ◽  
Siqi Li ◽  
Shiyuan Ding ◽  
Qinkai Li ◽  
...  
Keyword(s):  
Water Column ◽  
Southwest China ◽  
Water Column Stability ◽  
Denitrification Process

A model study of the regulation of blue mussels by nutrient loadings and water column stability in a shallow estuary, the Limfjorden

2010 ◽  
Vol 64 (3) ◽  
pp. 322-333 ◽  
Author(s):  
Marie Maar ◽  
Karen Timmermann ◽  
Jens Kjerulf Petersen ◽  
Karin E. Gustafsson ◽  
Lars Mølgaard Storm
Keyword(s):  
Water Column ◽  
Blue Mussels ◽  
Nutrient Loadings ◽  
Water Column Stability ◽  
Model Study ◽  
Shallow Estuary
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