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Hot Knots

Never tie an improved clinch again.

The uni knot is versatile, easy to tie, and strong. Use it to tie on hooks or join two lines together with the double uni knot. Works great for tying dissimilar lines together or a leader to braid. For tying a braid backing to heavier mono or even a leader to braid the Red Phillips knot is faster and smaller.

The Water:  Wind, Waves, and Currents

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Wind Driven Water:  Surface Waves and Seiches

The action of the wind on the water's surface creates waves.  These waves move energy, nutrients, and water throughout the lake through three main mechanisms:  wind induced drift current, surface seiche waves, and internal waves (thermocline seiche).

Wind induced drift current refers to the "normal" surface and subsurface currents we think of.  Friction between wind and water moves the water in the direction of the wind, at a small ( 1-3%) percentage of the wind speed.  Breaking whitecaps in open water add more forward energy to the current.  These currents move the surface water, and if the wind is strong enough, the water piles up at one end of the lake, literally raising the water level.  There is a matching drop in water level at the other end of the lake, where the wind is blowing from.  These variations are usually slight, a few inches on the Finger Lakes, however, strong wind events can move substantial amounts of water and raise the water level a foot or more.  The long, narrow basins of the Finger Lakes channel wind and water, and the surface of the lake is rarely still.  Even with no wind, currents from the previous days' blow exist and the water will be sloshing water back and forth.

Subsurface, a return current moves in the opposite direction.  While drift current conditions prevail on the surface, the displaced water has to go somewhere and a corresponding return flow develops deeper in the water column.  The speed of this current is generally one half that of the surface current.  During summer months the return current is strongest at the depth of the thermocline, and opposite the wind direction.  During winter the depth of return currents can vary widely, from near-surface to the very bottom of the lake.   The existence of the return current is very important, as during the summer months, most trout species will be found below the surface!

Seiche Waves are caused by the movement of water by wind action.  As a sustained wind blows, the surface water is pushed down the lake and piles up at the far end.  The surface of the lake actually tilts and becomes slightly off the horizontal.  When the wind stops or significantly changes direction, this pile of water heads toward the other end of the lake!  This is a surface seiche wave, and in Cayuga and Seneca lakes the period (length) of the seiche is roughly one hour, and much shorter in the smaller, shorter lakes. 

The seiche will oscillate back and forth, gradually damping, until it is absorbed or further wind starts the cycle again.  Sometimes several seiche waves are present in the lake at the same time.  Wind events will cause seiches across the width of the lakes as well, but the wind is only able to push the water for a short distance and these seiches are usually small, but large ones can occur.  I was personally witness to a spring thunderstorm with strong straight-line winds at the southern end of Cayuga Lake.  It quickly blew through and I resumed fishing, for carp I believe, near Stewart Park in the Fall Creek estuary.  There was a slow visible current out to the lake of perhaps 1 mph. 

Just after I got out of my truck and to the bank, I noticed the water level dropping significantly.  Five to ten minutes later a branch floated by.  About two minutes after that, the same branch floated by in the opposite direction, going back upstream!  The water level quicky rose again as the creek continued to flow upstream for several minutes.  This process then repeated itself for an hour or more, slowly dying out, until all was well and the creek maintained a level flow to the lake.  The first several seiches raised and lowered the water level more than a foot, then about eight inches, then six, then three, then it was more or less gone, the water level continued to rise and fall a small amount but the creek kept flowing out.  The period of this seiche was approximately 15-20 minutes, I didn't time it so I can't say for sure.  Still; I saw Fall Creek flow backwards, a pretty cool phenomenon! 

An internal wave is really an internal seiche, and describes the movement of water in the depths, specifically the metalimnion.  These waves develop in response to surface seiches and drift current conditions, as there is no direct wind effect on the subsurface waters.  Invisible from the surface, they are of great importance to the fisherman!  They are also responsible for the greatest amount of water movement within the lake and strongest currents.  These waves are present only during stratified conditions, for they are waves in water density and temperature- essentially, waves in the thermocline and metalimnion.

As warm surface water is moved down the lake by the wind and begins to circulate against the far shore, the cold water below is forced in the other direction.  Eventually, the thermocline will develop a tilt, deepening at the far end as warm water pushes it down, and moving shallower at the other end, where the wind is coming from, as cold water moves in.  With a strong enough wind that blows long enough, the entire epilimnion may be blown off one end of the lake, causing an upwelling of cold bottom water on the surface.  This is the phenomenon most associate with a lake "turnover", as the resulting wave breaks on the northern and southern shelves, stirring up massive amounts of sediments and dirtying the water for days.   The large internal seiches associated with high wind events are the reason for the poor fishing afterwards- there are strong, quickly changing currents within the depths of the lake, and the depth of the thermocline will vary wildly within the lake.  The fish are more difficult to locate and are more likely to be moving around.

These effects are most pronounced at the "antinodes", the "ends" of the wave oscillation.  The North and South ends of the lakes are antinodes, with one or more "nodes" located between them.  The nodes feature low vertical movement of the thermocline and high horizontal current velocities.  The antinodes feature high vertical movement of the thermocline and relatively low horizontal current velocities.  This means there are locations in the lake where the thermocline remains at a relatively constant depth, and these areas can attract fish.  The period of these internal waves are roughly 2 to 2 1/2 days on Cayuga and Seneca, much less on the smaller lakes.  There are usually several resonant frequencies of waves within a lake, creating many nodes and antinodes, but the main, first order wave moves the most water and is most frequent and important.  No need to get into that, it's complicated enough!

A look at the Cayuga Lake basin shows the long-term effects of internal waves- there are great gravel and sediment bars across the lake at several distinct points, seperating the deep water basin into distinct zones, the result of thousands of years of internal waves.  Deep soundings of the Finger Lake basins show bedrock valleys approaching 800 feet or more, suggesting most of the Finger Lakes are at least halfway filled in already.  Thus any variations of the relatively flat lake floor in deep water are due to currents and sedimentation rates, and a study of a depth map can yeild many clues as to the circulation patterns within that lake.  


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