Lake Temperature Question

I was wondering if there is a scientific explanation or any explanation why the water temperature at the lake right now is so much warmer (well, three degrees) than it was at this time last year? Considering that this winter was soooooo cold, it strikes me as kind of odd.

Could it be that the lack of snow let the ice absorb the sunshine while all the snow last insulated it? Just hypothesizing here.

Jersey Girl

More than likely its the lack of calibration or location of thermometer/sensor being used

It seems that it was much colder last year (maybe not for such a long period of time)

Good question. Heating oil contractors will tell you this was the coldest winter since 1918. Personally, I don't remember back that far...Thank goodness!!!!

and neither do they, lol! they just look up the records on the web the same way we do, or hear it on the news like us

The temperature posted is not the average lake temperature. It is the temperature of one thermometer near the Lakeport Dam about a foot below the surface. Given the warm weather for the past ten days, the reading given is not surprising.

If one wants to measure the amount of heat contained in Lake Winnipesaukee, the thickness of the ice is a better indicator.




www.bizer.com

I think the lake temp is reading warmer because of how much water they let out. In the begining of the year the lake was high and they opened the dam alot. Thus all the colder water near the top going down stream.
I'm not a weather man but I did stay at a holiday inn express....

Jersey Man

It seems to me that I was taught that heat rises, and I think that can be confirmed in the summer as the bottom of the lake seems cooler to me than the top. But then the problem comes that the top is the part that is frozen not the bottom. Well, it will not be long, April 9th at 10 O'clock will be Ice Out this year, and it will be the first time that Ice out has been recorded on that date.

It seems to me that I was taught that heat rises

There are exceptions to the fact that heat rises. One of them is water. Water is at its densest at 39 degrees F. If one were to go out into the Broads and drill a hole in the ice, the water temperature at the surface would be 32F. Ten feet down the temperature would be 39F.

Another exception to heat rising: The air is colder at the top of a mountain (but that's another physics lesson).




Bizer's chart of Lake Winnipesaukee

There is a great description of this on the Squam website that I have referenced before. See link below.




Spring/Fall lake inversion

Bizer...

Heat ALWAYS rises. The reason the water is "warmer" at depth is because of the cooler air above the surface of the water, "carries away" thru convection, the heat from the surface of the water, causing the surface to cool and form ice.

Mountain tops are similar except that the air is less dense, (the higher you go, the less air there is) and thus there is less solar heating. The colder high altitude winds don't help either.

Heat in a vacuum (negative air pressure) is a whole other issue...

Professor,
Your credibility is SHOT !
Heat does not rise....heat seeks cold PERIOD ! Up, down, sideways, it does not know the difference. Check your textbook!!
Warm air rises...that's a totally different matter.

Heat cannot "seek" anything. This implies will, of which heat has no ability. Heat causes (in most cases)a given substance expand. It also (in the case of air) causes a transfer of molecular movement energy from a higher excited state (warm air) to a lower excited state (cooler air).

The statement that "hot air rises" is also not totally accurate. Air tends to expand as it is heated (as long as presssure remain a constant). Within a given pressure range a volume of heated air will rise above cooler air due the the fact that the given volume of warmer air is less dense the the cooler air surrounding it. However, many factors to lengthy for discussion in this particular thread have can cause heated air to do anything but rise (pressure variations, forced air circulation, moisture variations, etc.)

Now, back to the claim that a floor heated with radiant tubing produces heat that "clings" to the floor and doesn't rise to the ceiling. All quotes attributed (with cited links) to this claim always refer back to sources that produce radiant heat flooring systems.

Hogwash!

Radiant heating in the floor is perceived as more comfortable heat because the initial heating is felt by the foot and lower leg, areas of your body that are normally cooler due to the nature of forced hot air or traditional baseboard heating units.

Even though the thermodynamics of heated air are the same, whether the air is heated by any number of sources, you perceive more comfort with a radiant floor.

Thats it, plain and simple. The inventors of radiant heat flooring were clever, but not clever enough to fool the laws of thermodynamics, just smart enough to sway the average consumer (and many web site posters).

And in sales, as in most areas of life, perception is everything!

HMMMM...sounds like you got a lot of edumacation. But we are getting into symantics as to what heat does....it is a form of energy that will be released to and as it comes into contact with anything that is colder than itself. It is oblivious to direction ( and I'm not implying it KNOWS anything ). If the colder mass is up, that's where it will go. If the colder mass os down, that's where it will go....guess where it will go if the colder mass is sideways?

I'm done with this post..

Bobby BTU... I was going for the simpler explanation/approach, but basically you said it better. Al needs to go take a thermodynamics course...

Proffesor Physics

Ok, I can't resist,

Let me clear this up once and for all:

"The zeroth law of thermodynamics asserts that certain thermodynamics notions such as “temperature”, “equilibrium”, and “state” make sense. This is sometimes but not always a useful approximation.

The first law of thermodynamics states that energy obeys a local conservation law. This is true and important.

The second law of thermodynamics states that entropy obeys a local law of paraconservation. This is true and important.

The third law of thermodynamics alleges that the entropy of some things goes to zero as temperature goes to zero. This is true except when it’s not true. It’s not very important."

In the very short time I've spent reading the responses, I think Uncle Al is right in the purest sense, so is Bobby Btu, although admonishing for using the word seek is getting petty. Professor Physics, the statement "Heat always rises" is wrong, as explained by Bobby, and in a purer sense by Uncle, but that doesn't mean your totally wrong. Let's move on.

The interpretation of the Laws of Thermodynamics were lifted from the below Website. Don't forget they're not just a good idea, they're the law.




Thermodynamics Link