Naked Science Forum

Life Sciences => The Environment => Topic started by: Lou Diaco on 27/02/2012 20:55:39

Title: Changing the temperature of water (this is alot more interesting that you think)
Post by: Lou Diaco on 27/02/2012 20:55:39
Hello all,
While watching the Discovery channel, a program about hurricanes came up.  It mentioned that water must be above 80 degrees Farenheit for these storms to form, and more importantly, that once the temperature of the water it is above goes below that temperature, the storm quickly looses energy and strength.  Now I am a public policy analyst, and I know that every year, billions of dollars of damage are caused by hurricanes, so I want to explore the feasibility of reducing the severity of hurricanes, or even break them up before they are "born".  My main area of interest concerns hurricanes that form on the west coast of Africa or in the Gulf of Mexico.

Now to the science.  I have been unable to make heads of tails of the equations I might need to theoretically test my own idea; Use ice cubes to lower the water temperature of a few square miles of surface water from about 85 degrees to 75 degrees.  I must imagine that such change would at least disturb a hurricane.  So here is my question:  What equations must I use and what variables must I consider (such as size and temperature of the ice cubes) to determine how much ice it would take to cool "x" amount of water from ~85 degrees to ~75 degrees?

Any insights you may have concerning this idea of mine are greatly appreciated.  The only thing I don't want to hear anyone say is that its dumb or not feasible without providing evidence.  I'm not asking you to do the calculations, all i really need is some scientific guidance.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: CliffordK on 28/02/2012 00:02:38
It is a pretty tall order to make "ice cubes" to cool the oceans.

Here is a good site for Fahrenheit sea surface temperatures for the last year or so.
http://www.ssec.wisc.edu/data/sst/

And, for Celsius (all I'm seeing is current temps for some reason)
http://www.ospo.noaa.gov/Products/ocean/sst/contour/index.html

What is obvious is about a 10+°F or  5+°C temperature annual shift from summer to winter covering an enormous area in the mid latitudes.

The energy requirements to produce and transport enough ice de novo to significantly cool down, even a small area such 10 miles x 10 miles (100 square miles) would be enormous.  If we believe that our energy usage is making the sea surface temperatures warmer, then that would be like shooting ourselves in the foot. 

As we know, there is a lot of ice in the poles.  If we could just carve off a few blocks of ice and move it from the poles to the mid-latitudes...  before it melts.  Ignoring, of course, the goals to keep some of the ice IN THE POLES. 

There are two types of ice, glacial ice (and ice shelves), and sea ice.  The larger ice bergs would be of glacial origin.  But, the amount of ice you would need is beyond our capabilities to transport before it melts.  Consider the Titanic that was dwarfed by a single iceberg, which undoubtedly melted in the northern latitudes.

How much ice would it take to cool that 10 mile x 10 mile surface area by, say 5°F/2.5°C?  Perhaps a cubic mile of ice?  And, the result is still a very local effect.  Would it break up a single hurricane?  Or, just lower the wind speed by a few mph?

One option that might be undertaken in the future.  There have been proposals to make a space based sun-shield to cool the planet Venus.  But doing so would be an enormous engineering task.  However, if that would be possible, one could also make a sun-shield for Earth, either solar panels to generate energy, or mirrors to either send sunlight to where it is desired (more heat in the winters?)  But, consider the engineering task to build a sun-shield the size of the USA.

Another option to consider, in the oceans there is plenty of cold water, about a mile deep.  One can build heat exchangers that will pull cold water from the depths and release it at the surface.  It should be possible to make such a system self-powering based on the temperature differences, or even generate energy.

Doing it on a small scale, the cold water would quickly be replenished from the poles.  But, even to systematically cool the desired 10 mile x 10 mile area would require an enormous heat exchanger.  But, if one community got it, wouldn't everyone want it?  Would it cause more harm to the oceans than good?  Disturb the fine temperature balance of the deep oceans?  Potentially releasing the underwater methane reserves?

I suppose it never hurts to do primary research, but at this point, I believe the cost of such a cooling system outweighs the benefit.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Don_1 on 28/02/2012 10:48:12
As Clifford suggested, short of towing huge icebergs from the polar ice caps, I don't see how you could get sufficient ice to have any significant effect on sea temperatures without an enormous cost, both financially and in terms of energy generation, which would be counterproductive.

Carving off a few 10 million ton icebergs from the polar sea ice and towing them into the Gulf of Mexico would reduce the sea ice, thus increasing sea temperatures around the Polar Regions, albeit temporarily, which in turn would increase sea temperatures further afield. Perhaps as far as the African coast and the Gulf of Mexico.

Quite apart from the above, the polar ice caps have an enormous influence on weather systems worldwide. The shrinking arctic polar ice is already having a tremendous effect on weather systems. It is probably the cause of the change in the course of the jet stream. Add this problem to a 10o drop in the temperature of the Gulf of Mexico, which would result in a significant drop in the temperature of the Gulf stream, and you put western Europe in danger of becoming more influenced by Siberian weather systems than Gulf systems. Europe might see devastating drops in winter temperatures and equally devastating increases in summer temperatures.

Cities far from the coast, such as Berlin, could become roasting hot in the summer and totally buried in many metres of snow in the winter, while London, which benefits from both the Jet stream, and Gulf stream could become a desert, if (and its an big 'if') you could actually do as you propose.

You are quite right to see that systems far from the US have an effect on the US, but you seem to be closing your eyes to the fact that those same systems have an effect on other parts of the world too.

Quite honestly, I don't think your vision is feasible from the financial point of view, the practical and logistical point of view and certainly from the ecological point of view.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: CliffordK on 28/02/2012 12:34:38
One may be able to hunt hurricanes and try to disrupt them prior to landfall.

However, if you look at the size of a hurricane such as Katrina, it is just ENORMOUS.

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fthumb%2Fd%2Fdb%2FNOAA-Hurricane-Katrina-Aug28-05-2145UTC.jpg%2F220px-NOAA-Hurricane-Katrina-Aug28-05-2145UTC.jpg&hash=d2f2bebdcdece56991b6bcb2db8bf148) (http://en.wikipedia.org/wiki/File:NOAA-Hurricane-Katrina-Aug28-05-2145UTC.jpg)

So, if cooling the gulf would take away energy from it, one might have to cool a large part of the gulf.  No doubt it would do little to just put a small cooling station in front of New Orleans.

Perhaps one could chase the hurricanes as they form, but many of the hurricanes never make landfall.

http://en.wikipedia.org/wiki/2011_Atlantic_hurricane_season
http://en.wikipedia.org/wiki/File:2011_Atlantic_hurricane_season_summary_map.png

But, some years like 2005 are just bad years.
http://en.wikipedia.org/wiki/2005_Atlantic_hurricane_season
http://en.wikipedia.org/wiki/File:2005_Atlantic_hurricane_season_summary.jpg

No doubt, there are many sea critters that like warm water in the summer.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Lou Diaco on 28/02/2012 14:18:57
Just as I thought would happen... nay sayers.  CliffordK, you were somewhat helpful in your discussion about icebergs and such, but the two people who posted here don't seem to grasp the needed scope of this project.  Its really my fault for mentioning the calculation's purpose, but the cat's out of the bag so to speak.  I am first and foremost a champion in the fight against global climate change.  My very last desire would be to harm Mother Earth more than she has already by stealing the polar ice caps or icebergs.  What my plan was looking to do was to make a short term reduction in the SURFACE temperature of the ocean.

Please listen carefully.  It takes days for a storm off the coast of Africa to turn into a tropical depression, then into a tropical storm, and then into a hurricane.  Meteorologists can project if a tropical depression is likely to turn into a tropical storm or hurricane, and even where it is likely to head.  What I am suggesting is that during the buildup of the storm's power, humans intervene to disrupt its course and and flow.  The reason I mentioned ice cubes was because all I think I need, is to lower the surface temperature to about 75-78 degrees Farenheit.  Size doesnt really matter when you start dealing with such small things.  Think of how many times used and discarded empty water bottles can circle the earth.  The USA is good at mass production.  Do you think Ben Franklin would have tried to discover electricity if he was concerned with the utility of such a discovery?

 All I really want to know are the formulas I need to compute the change in temperature of a given amount of water, if a certain amount of material at a different, lower, temperature is added.  Anyone able to give me that?
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: peppercorn on 28/02/2012 22:51:51
Meteorologists can project if a tropical depression is likely to turn into a tropical storm or hurricane, and even where it is likely to head.
- Can they? Over what time-frame?
If a storm grows exponentially over, what, 2-3 weeks, say - everyday you need to dump perhaps twice as much ice (if your principle even holds) into the water as the day before.

I find it odd that you claim you would never do anything that would add to further instability in the Earth's climate. But in the next breath suggest a scale of geo-engineering (with utterly un-model-able[?] climatic results!) that will take terrawatts of power annually to implement.  At present humanity is showing no willingness to cut back on burning ancient carbon, so the last thing it needs is to do more of it.

Ironically the biggest driver that will continue to increase the frequency and severity of hurricanes is predicted to be the only relatively small increments in global temperatures - a result of the dreaded CO2 increase.

If you are actually interested in saving the most human lives and suffering rather than those who are both living in hurricane hotspots and who may be rich enough to pay larger taxes why not, for example, concentrate on the 'easy' (relatively) fixes of paying to stop deforestation or palm-oil impact on Malaysian peat swamps (millions of tons of methane [20xCO2 impact] released annually).
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Cheese2001 on 29/02/2012 00:46:07
Lou,

The basic answer to your question is the amount of mass you want to cool.  We'll make a couple basic assumptions, and then see how the numbers fall out.  The process you're thinking about is governed by Newton's Law of Cooling.  Two algebraic results of the Law of Cooling are:

Q = c * m * dT    (Energy required equals coefficient of heat times mass times the temperature change)
and
Q = m * L (Energy required is the mass times the coefficient of Latent Heat)

We need the mass of water, lets us 160 km x 160 km square down to 20 meters.  The area is about 10,000 square miles of ocean and the depth is about 60 feet.  The surface area is much smaller than an entire hurricane, but larger than the eye.  The depth keeps us in the mixing layer of the ocean and will keep it about the same temperature.  As you go deeper in the ocean, it gets colder, so we don't need to cool and entire column of water from the surface to the floor of the sea. 

Our volume is 5.12x10^11 m^3.  We know the density of sea water is just over 1000 kg/m^3, so the mass is 5.12x10^14 kg.  We also know the coefficient of heat for water is just over 4000 J/kg.  You mentioned 10 degrees F which is about 5.6 degrees C.  Now let's use that first equation to see how much energy is going to be required:

Q = 4000 * 5.12x10^11 * 5.6 = 1.15x10^19 Joules

An enormous amount of energy!  In more useful terms it is equivalent to 1.09x10^16 BTUs or 3.15x10^12 kW-h.

So, now that we know how much energy needs to be dissipated, how are we going to do it and what's the cost?  We'll explore two options:  An unknown electrical option and your suggestion of ice.  Electricity costs about $0.02 per kW-h in the US, so we are going to spend about $63,000,000,000.00 per hurricane ($63 Trillion).  Way too expensive, so lets look at the ice option.  We know how much energy needs to be absorbed... so lets use the two above equations and solve for mass.  The total energy is the sum of the temperature change and the latent heat of melting.  The latent heat of melting for water is 334,000 J / kg. 

Q = c * m * dT + m * L  ==> solve for mass ==>  m = Q / (c * dT + L)

I get 3.2x10^13 kg.  So we need about 6% of the mass of the water in ice form to change the temperature 10 degrees!  You can check the math with stuff you have at home.  You'll need a cup, a scale, some water, ice, and a food thermometer.  Watch your units, and ensure they are appropriate, but here's how it works:  measure and record the mass of the empty cup, put water in the cup and measure the mass again.  Take the difference and you have the mass of the water.  Measure and record the temperature of the water, and you'll have the first temperature point.  Put ice in the cup, and re-measure the mass of the cup, water and ice.  Take the difference to get the mass of the ice.  AFTER the ice has COMPLETELY melted, take the temperature again.  The difference in the two temperatures is your dT.  You can take the ratio of ice to water and the temperature difference to scale the result to any size you'd like!

The numbers used here are readily available on the internet to higher precision, I used rough numbers just for ease.  Hope this helped!


___________
Post edited to correct number transcription errors.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: yor_on on 29/02/2012 02:41:55
Sweet calculation.

Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: CliffordK on 29/02/2012 08:10:47
Our volume is 5.12x10^13 m^3. 
I came up with 5.12x1011 m3
for 160km x 160km x 20m
Still it is HUGE.

So we need about 6% of the mass of the water in ice form to change the temperature 10 degrees!

I like calories for the calculation...  although not the universally preferred unit here on TNS.

Latent heat of fusion of water, 80 calories per gram (or cc).
22 calories to heat water from 0°C to 22°C.
Total: 102 calories per gram of ice to 22°C.

one also increases the final volume of water by adding the ice.

Anyway, it works out to be an equivalent of about 4.7% of the mass equivalent in ice to decrease the temperature by 5°C.  It would be about 5.2% for 10°F. A little lower, but close to what you got.

The largest iceberg in recent recorded history was the Iceberg B-15 (http://en.wikipedia.org/wiki/Iceberg_B-15) calved from the Ross Ice shelf in March 2000 with a mass of about 3 billion tonnes. 

So, I come up with that one iceberg being capable of dropping about 6.42x1010 m3 by 5°C.

Which is about 10% of the target.

But...  keep in mind that was an ENORMOUS iceberg. 
Moving it to the equator would not be an easy or cheap task.

Your best bet, though, rather than investing the energy to either make or move ice, to get the 80 calories / cc + 22 calories to raise the temperature, to just pump water from the deep at less than 5°C, to get about 17 calories equivalent per cc for the dilution, and likely substantially less cost. 

However, I would be very concerned about the environmental impacts of either pumping the water from the deep or even just moving the icebergs into location. 

While the temperature of the ocean the may be going up slightly, the majority of the 10°F annual change is normal annual variation.

If you attempt to dissipate the storm near the source.  If they aren't 100% dissipated, they would likely regain energy as they moved towards shore, and the effort might only be marginally effective in decreasing the storm's energy.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Geezer on 29/02/2012 08:48:07
er, sorry to be a spoilsport, but if you do ANY work to rearrange things, unless that work is done by a mechanism that is 100% efficient, you will only add more heat into the system, and that seems a bit counterproductive.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Don_1 on 29/02/2012 11:38:10
Like Peppercorn, I too am somewhat bemused by your statement "I am first and foremost a champion in the fight against global climate change.  My very last desire would be to harm Mother Earth more ......" since that is what you are aiming to do.

You propose to cool the surface water only. How do you propose to do that? Cold water sinks, warm water rises. What's more, the oceans are virtually constantly stirring themselves. Your ice cubes would melt so fast, you would need to have a constant supply for anything up to 3 weeks. The amount of energy required to produce sufficient ice and supply the logistics would be, as I and others already said, counterproductive.

Cheese:-
I would not dare to question your mathematics, but your calculations seem to be based on laboratory conditions. You suggest that any of the figures can be checked at home using a cup of water, again I would not dispute your statement. Even any trials in a bath tub or swimming pool may give similar results to confirm your calculations, but oceans, with constant movement at the surface and undercurrents, circulating warm air above and the Sun’s rays, would not behave in quite the same way. These unknown, unstable and unpredictable conditions would make any controlled situation experimentation worthless.
Nonetheless, welcome to the forum.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Cheese2001 on 29/02/2012 14:49:00
CliffK,

You are correct, I mistyped the numbers from Excel.  The numbers are correct in the spreadsheet, so the rest of the values should be correct.

Don and Geezer,

The equations are absolutely based on lab conditions.  Further, to get really precise numbers you'd want to use a calorimeter and really get good numbers.  But, our original poster wanted to know some factual reasons why it couldn't be done with some scientific reasoning.  There absolutely are many more perturbations that would decrease the efficiency of any solution, requiring much more energy or mass than I've calculated.  But if the lab conditions are beyond the bounds of practicality, the real-world conditions are much more beyond the bounds of practicality.

I am having fun in the forums so far though!  Thanks for the welcoming!
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: yor_on on 29/02/2012 18:05:26
Let me add to that welcome Don.
As a guy prepared to take a question at its face value and walk it through to the end, Cheese does two things :)

He walks it through in a understandable way.
And he shows some of the difficulties inherent, in the idea Lou proposed.

As for laboratory conditions you're perfectly right, but I had a good time reading it :)
And nicely spotted Clifford.

Keep on thinking Lou, we need people thinking.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Geezer on 29/02/2012 21:54:59
Cheese,

You may be missing my point. If you do any work at all, you will absolutely have to generate some heat. That heat is going to go back into the system which means it will make the original problem that you are trying to solve even worse.

It's a bit like rearranging the deckchairs on the Titanic.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Bored chemist on 01/03/2012 20:28:10
My lawyer friend is limbering up for the first time you use this.
The fact is that you almost certainly won't stop a hurricane- but you will move it somewhere.

Previously, if someone got hit by a hurricane it was nobody's fault and so there was nobody to sue (Apart from God perhaps).
However, if you move it  then it will hit people who would otherwise not have been hit. That's your fault.
Are you really well insured?
If someone gets killed are you prepared to serve time for manslaughter?
The really great thing is that even if your scheme doesn't work, I can still claim it did and sue you.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: damocles on 01/03/2012 22:17:34
Problem: huge destructive storms originating at latitudes around the tropics (i.e. ~15° to 30° N or S).

Proposed solution: reduce sea surface temperature by about 5°C. -- (Judgement: If this is feasible, that is a solution that will be effective.)

New problem: How to reduce sst over a large area?

Horizontal solution: Tow in icebergs -- (Judgement: Order-of-magnitude feasible but very expensive in financial, manpower, and energy terms. May not be practical. It is worth checking out this website:
http://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/ (http://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/))

Problematic issues associated with horizontal solution: • Depletion of polar ice. • Partial melting en route • Ecological disruption at polar source, along mid-latitude route, and at tropical destination. • International law issues over ownership of icebergs if the scheme ever became large-scale and competitive.

Vertical solution: Mix surface water with cold underlying water, which is abundant at and below 200 metre depth.
http://en.wikipedia.org/wiki/Thermocline (http://en.wikipedia.org/wiki/Thermocline) -- (Judgement: Untried, even on a pilot scale. Uncertain logistics of how to achieve this over a very large area. Certainty of large ecological change right through the area. A large speculative "maybe".)

Possible vertical solution details: Use thermal gradient -- but that will reduce the cooling efficiency • to power pumping agitation OR • to promote extra evaporation through splashing or air circulation, which could create a surface zone of higher salinity and density, which could destabilize the thermocline and lead to some extra mixing between surface and deeper water.

Bizarre solution: Run a float line from Miami via Cuba to Cancun, or from Miami via Puerto Rico to Venezuela, and dump tons of bean bag fill or similar to spread across the contained surface. This will greatly reduce the surface insolation that causes the high temperatures in the first place. It might also have major commercial and ecological side-effects.

Major environmental side effect not yet mentioned: The "Gulf Stream" is so named because it originates in the Gulf of Mexico, and is very sensitive to events there. It is in delicate balance. The UK and Ireland are at the same latitudes as Goose Bay and Juneau, But the Gulf Stream keeps their climates much warmer than those of those two American centres. Any of the proposed solutions applied in the Gulf or the Caribbean, but most particularly the 'vertical solution', may well disrupt the flow of crucial ocean currents, and "throw the dice" on the climates of heavily populated Western Europe.

If you are on the Titanic, you probably have little better to do than trying to find the optimum arrangement of deck chairs.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: CliffordK on 02/03/2012 00:10:18
My lawyer friend is limbering up for the first time you use this.
The fact is that you almost certainly won't stop a hurricane- but you will move it somewhere.
The goal is not to move the hurricane, but to either dissipate the hurricane completely, or to reduce the strength of the hurricane.

Although, it is possible that even if one completely dissipates some storms, additional ones would pop up in their place. 

It is a good point though, what is good for Florida and the Eastern USA might be very bad for Europe and the UK.

Or, it could have other unforeseen consequences, such as vertically pumping water against the thermocline could disrupt the fine equilibrium in the methyl hydrates causing very severe consequences.

One other thing to consider.  Certainly different houses are affected differently by a hurricane.  If one chose to do so, it should be possible to make highly hurricane resistant housing.  (http://en.wikipedia.org/wiki/Hurricane-proof_building) Or, for that matter, also building tornado resistant housing. (http://web.bsu.edu/capweb/portfolio/architecture/march/2008/Clemens_David.pdf)

The problem is that it may cost 2 or 3 times as much to build the hurricane proof houses.  So, people choose not to do it, and rather rely on luck and insurance.

Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Don_1 on 02/03/2012 10:08:09
My lawyer friend is limbering up for the first time you use this.
The fact is that you almost certainly won't stop a hurricane- but you will move it somewhere.

Previously, if someone got hit by a hurricane it was nobody's fault and so there was nobody to sue (Apart from God perhaps).
However, if you move it  then it will hit people who would otherwise not have been hit. That's your fault.
Are you really well insured?
If someone gets killed are you prepared to serve time for manslaughter?
The really great thing is that even if your scheme doesn't work, I can still claim it did and sue you.

A very good point and one which those litigious Americans would doubtless explore and take full advantage of.

Lou, I understand your concerns and your wish to explore any avenue which might alleviate the problems faced by those states in hurricane alley, but attempts to interfere with some of the world's most powerful and influential weather systems would be unaffordable and unlikely to be successful.

As I and others have pointed out, should you manage any degree of success in calming or altering the direction of any hurricane, it can only be at great ecological (and perhaps financial) cost elsewhere. Just suppose you were to achieve your goal. What might happen to marine life in and around the area of the Atlantic affected? Fish, mammals, turtles, coral, plankton etc both resident and migratory 'passing through' traffic could be displaced due to temperature change.

I'm afraid you are stuck with hurricanes. Your only means of defence is better forecasting and hurricane proof construction.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: CliffordK on 02/03/2012 11:52:52
There haven't been many comments on whether there are in fact benefits of the hurricanes.

According to Wikipedia:
Quote from: http://en.wikipedia.org/wiki/Effects_of_tropical_cyclones
Hurricanes help to maintain the global heat balance by moving warm, moist tropical air to the mid-latitudes and polar regions.  Were it not for the movement of heat poleward (through other means as well as hurricanes), the tropical regions would be unbearably hot.
I presume they also help move energy upwards into the upper atmosphere, and thus release the energy from the planet.

The hurricane does naturally mix some of the sea water, so perhaps one could do some of the mixing for it.  However, the thermocline also may influence the intensity of the hurricane. 

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.hurricanescience.org%2Fimages%2Fhss%2FGOMandCarribSeaOceanicMixedLayer.jpg&hash=5efd7fa4d38b17b2aa40edd549a6938f)
Quote from: http://www.hurricanescience.org/science/science/hurricaneandocean/
Three-dimensional cartoon of the temperature distribution in the upper ocean and the impact of a hurricane passing over the ocean when the oceanic mixed layer is thin like much of the Gulf of Mexico (left) and thick like the Caribbean Sea (right). In both cases, the hurricane propagates down and left over the warm sea surface (red), creating a cold wake behind the storm as colder water (blue) is brought towards the sea surface by the hurricane’s wind stress. If the oceanic mixed layer is initially thin (left), the cold wake is colder so the hurricane remains weaker than if the oceanic mixed layer is initially thick (right), all else being equal. Image credit: National Geographic Magazine.
So, if mixing warm surface water with cold deep water in an effort to dissipate a hurricane's energy would cause a reduction in the thermocline, then it might in fact increase the risk for more intense hurricanes in the future.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Bored chemist on 03/03/2012 16:08:07
It might be easier to stop building stuff in the path of hurricanes.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: CliffordK on 04/03/2012 10:43:42
It might be easier to stop building stuff in the path of hurricanes.

The problem is that essentially the entire Eastern USA from Texas to Florida to Maine is in the path of hurricanes.  While the power and risk of storm surge decreases quickly inland, it would be difficult to say ignore a 100 mile strip along the coast.

Does the USA get off easy?  Maps of the Pacific Typhoons indicate that Asia gets hit heavily.  Are they all strong?

One can ask whether it is wise to build houses below sea level in a place with hurricane and storm surge risk.  But, otherwise, I think more effort should be put in designing and building storm resistant housing.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: damocles on 04/03/2012 10:55:01
Taiwan, Hong Kong and Southern China, Japan, and the Philippines all get regularly hit by typhoons. Taiwan is well prepared, Philippines poor and poorly prepared, other places you do not get much news about devastation -- I suspect more because of restricted news than lack of problems. Typhoons can be every bit as strong as hurricanes

Same phenomenon:

Hurricane (North America)
Typhoon (East Asia)
Tropical Cyclone (Northern Australia and a few other places).

Cyclones can cause a lot of damage in Australia, but their tracks are mostly lightly populated, and in recent times people have been well prepared. Tropical cyclone Yasi did huge damage in a tourist/sugar cane/fruit growing area of North Queensland in Feb 2011

http://www.brisbanetimes.com.au/photogallery/environment/weather/yasi-hits-north-queensland-20110202-1acrd.html (http://www.brisbanetimes.com.au/photogallery/environment/weather/yasi-hits-north-queensland-20110202-1acrd.html)
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: SeanB on 04/03/2012 12:44:27
Sitting here in the rain from tropical storm Irene, has been raining steadily for a day now. luckily it is moving inland north of me, should bring some very welcome rain to the interior parts. Mozambique though is swimming again. Advisories of heavy swells out at sea, and warnings to all shipping about this.

So far about 5 inches of rain has washed all the roads, roofs and popped manholes all over.

I will be swimming tomorrow going to work, but the drains there are clear, cleaned last year of a lot of debris and fixed a few leaking and cracked pipes.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Cheese2001 on 04/03/2012 23:03:31
http://www.usatoday.com/weather/resources/askjack/wfaqhurm.htm

Interesting Q and A from the USAToday newspaper about what has been attempted and tested to weaken hurricanes.  There are discussions about icebergs, water absorbing materials, nuclear warheads, and coating the ocean with chemicals to limit water evaporation.

-Cheese
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: CliffordK on 05/03/2012 02:21:56
http://www.usatoday.com/weather/resources/askjack/wfaqhurm.htm

Interesting Q and A from the USAToday newspaper about what has been attempted and tested to weaken hurricanes.  There are discussions about icebergs, water absorbing materials, nuclear warheads, and coating the ocean with chemicals to limit water evaporation.

-Cheese
Great link.

The cloud seeding sounds like an interesting method.
http://www.usatoday.com/weather/research/2006-04-18-project-stormfury_x.htm
http://en.wikipedia.org/wiki/Project_Stormfury

In a sense, it is unfortunate that the project eventually lost support, and further testing was ceased.

However, keep in mind the final notes of the USA Today article:
Quote from: http://www.usatoday.com/weather/resources/askjack/wfaqhurm.htm
Q: Is trying to modify hurricanes such a good idea after all?

A: Today, scientists are more cautious about trying to modify the weather than they were during the 1960s. Hurricanes, along with other storms and ocean currents, help balance the Earth's heat budget. Trying to change hurricanes could have consequences that no one intended.

In fact, concerns about the potential negative impact of seeding hurricanes led to cancelling the idea of testing the Stormfury seeding typhoons in the Pacific.
Quote from: http://en.wikipedia.org/wiki/Project_Stormfury#After_the_seedings
The plan was to begin again in 1976, and seed typhoons by flying out of Guam. However, political issues blocked the plan. The People's Republic of China announced that it would not be happy if a seeded typhoon changed course and made landfall on its shores, while Japan declared itself willing to put up with difficulties caused by typhoons because that country got more than half of its rainfall from tropical cyclones.
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Don_1 on 06/03/2012 09:31:51
Coincidentally, the BBC screened ’Orbit: Earth’s Extraordinary Journey’ (http://www.bbc.co.uk/programmes/b00xztbr) (part 1) on Sunday, (part two next Sunday), in which Dr Helen Czerski touched on the relevance of hurricanes and their effect on the bigger picture of weather systems around the world.

Lou, I think your poll is missing an option. While I realise that you are more interested in the taxpayers willingness to cough up a little extra to pay for your scheme, I still think you should include an ecological opt out option; vis – ‘No, I do not want Man to interfere with global weather systems.’
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: damocles on 06/03/2012 09:43:53
Lou, I think your poll is missing an option. While I realise that you are more interested in the taxpayers willingness to cough up a little extra to pay for your scheme, I still think you should include an ecological opt out option; vis – ‘No, I do not want Man to interfere with global weather systems.’


Nice thought, Don, but the cat is already well and truly out of that bag!
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: Bored chemist on 06/03/2012 20:52:26
Damocles,
Weather<> climate
Title: Re: Changing the temperature of water (this is alot more interesting that you think)
Post by: damocles on 06/03/2012 21:17:46
Damocles,
Weather<> climate


Point taken, but climate is a strong determining factor of weather! Certainly larger numbers of more intense tropical storms is generally recognized as a direct consequence of any global warming that might occur. "Generally recognized" means seen in theoretical treatments, in computer climate modelling, and observed over last decade or two.

Insurance companies tend to be among the more conservative elements in our society, and they have been so drastically affected that they have been among the first of the conservative crowd to recognize the reality of global warming.