Temperature inversions

[spectrum]

I've heard of lakes where the thermocline reverses in winter. Do we have that happen around here? Just wondering if I might encounter the phenomenon in an ice dive or right after ice out in the spring.

From what I've seen watching buoy temperatures and depths the ocean is well enough churned to prevent this from happening.

Pete

 

[Diesel298]

actually it does happen in the ocean

 

[RIOceanographer]

Yup it happens in saltwater but the reason it happens is different from the reason it happens in freshwater.

Freshwater freezes at 0 degrees C but it reaches maximum density around 4 degrees C which means water colder than 4 degrees starts to become more buoyant until it freezes. If the water on top is less than 4 degrees C you can get a stable inversion.

Saltwater is different because the density increases right until it freezes so you can't get a temperature inversion for the same reason you do in freshwater. However, with saltwater the density is controlled by salinity and temperature so if the warmer water is enough saltier than the colder water, the colder water will still be less dense (more buoyant) and will float on top of the warmer and saltier water. This sort of thing is most noticeable in estuaries or near rivers.

 

[Gidds]

:geek:

 

[Rick Murchison]

Saltwater is different because the density increases right until it freezes

So if salt water does freeze it sinks, eh?
Rick

 

[Diesel298]

my brain hurts after reading that

 

[Rick Murchison]

We frequently get temp inversions in the Gulf when winter rains cause a layer of cold fresh water from rivers & streams to flow out on top of the warmer salt water.
Rick

 

[RIOceanographer]

So if salt water does freeze it sinks, eh?
Rick

Hey, I said "until it freezes", so the density can decrease all it likes after it freezes...

 

[spectrum]

my brain hurts after reading that

I got dizzy and had to go to bed. I think I can follow it in the light of day though.

Thanks for the info RIOceanographer.

Pete

 

[donacheson]

Yup it happens in saltwater but the reason it happens is different from the reason it happens in freshwater.

Freshwater freezes at 0 degrees C but it reaches maximum density around 4 degrees C which means water colder than 4 degrees starts to become more buoyant until it freezes. If the water on top is less than 4 degrees C you can get a stable inversion.

Saltwater is different because the density increases right until it freezes so you can't get a temperature inversion for the same reason you do in freshwater. However, with saltwater the density is controlled by salinity and temperature so if the warmer water is enough saltier than the colder water, the colder water will still be less dense (more buoyant) and will float on top of the warmer and saltier water. This sort of thing is most noticeable in estuaries or near rivers.

A curiosity question: At what salinity does the density of water fail to reach a minimum with temperature?