Tuesday, September 11, 2007

Hurricanes, typhoons, and cyclones: Variations

What impact would an infrared (IR) opacity-dominated climate ("global warming") have on cyclones, tropical cyclones in particular?

The tropical heat/moisture engine is modified. The basic features of an IR-opacity dominated climate are:
Putting back in turbulent convection and the hydrologic cycle gets us a few key compensating effects as consequences:
  • Enhanced vertical convection, moving heat upward more quickly and speeding up the air circulation "merry-go-round"
  • Enhanced evaporation, precipitation, and cloudiness
The air circulation "merry-go-round," on the largest scale, is just our friends, the Hadley cells. These will be enhanced in both speed and effectiveness of heat transfer. The earlier discussion of convection perhaps made it sound as if it is just a vertical, upward affair. It is for the heat. But the air, unlike the heat, does not escape the lower atmosphere. So there has to be some horizontal motion as an intermediate step between up motion and down motion. And there has to be compensating downward motion of cooler air, after it's given up its heat to the upper atmosphere, to preserve the overall mass of tropospheric air.

Consequences for tropical cyclones. If you think of the Second Law at work in the Earth's atmosphere by latitude, you realize that tropical cyclones serve the atmosphere's "need" to even out heat flow, overcoming the large difference between equator and poles and between high summer and autumn. If the temperature difference between poles and equator and between summer and winter narrows, even as the overall temperature goes up, the Earth's atmosphere has less "need" for tropical cyclones.

The specific mechanism that drives topical cyclones with excess heat and moisture is the nighttime temperature difference between the still-warm water and the cooler air.* "Global warming" will raise air temperatures more than it does water temperatures. Hence, the air-water temperature gap narrows, and the cyclone-driving "heat/moisture pump" is weakened. Some consequences of this change are difficult to trace out in full. But the essentials are unequivocal:
  • Poleward transfer of heat and moisture: reduced
  • Duration of tropical cyclones: reduced
  • Intensity of tropical cyclones: reduced
  • Frequency of cyclonic storms: hard to say, but an educated guess is: reduced
  • Poleward movement of tropical cyclones: enhanced by stronger Hadley cell and other convective motions
Overall, in a "globally warming" world, expect a (probably) reduced frequency of tropical storms, with each storm being less intense and shorter-lived, and moving more quickly poleward away from the equator.

Further thoughts on tropical cyclones. People living in tropical and subtropical areas obviously have a big stake in this question, and it's been manipulated and misrepresented by "global warming" fanatics eager to chase ambulances. In particular, whenever a major hurricane like Katrina or Rita hits a populated and developed area like the Gulf coast, we can expect more "global warming" hysterics. Little attention is paid to the big fact about hurricane-prone areas, that they're far more populated and developed now than they were 30 or 50 years ago. As a result, they will necessarily suffer more human damage when a large storm lands than they would have back then.

The irony of it all is this: more frequent, more intense, and longer-lasting Atlantic hurricanes are almost certainly an indicator of a summertime atmosphere that is cooling year on year. It's one piece of a growing body of evidence that the Earth's atmosphere, or at least the north Atlantic, has been cooling - in fact, since the late 90s.

Put simply, periods of warming (1920s and 30s; late 70s to mid 90s) are periods of reduced hurricane activity. Periods of cooling (late 1940s to mid 70s; since late 90s) are periods of increased hurricane activity. The reasons are just those spelled out above. An upcoming summary of the present climate situation will return to this point.
---
* As summer passes on into fall, the tropical air cools day by day faster than does the water. Recall that water has a much larger heat capacity than does air.

Labels: , , ,

3 Comments:

At 4:44 AM, Blogger Lucky7Star said...

Look cooling in the Atlantic does not mean Global Warming is not a factor or without consequence... The fact of the matter is the polar caps are dwindling at a rate never calculated or predicted by the models so all this cold water spilling into the Atlantic is sure to have a chilling effect. The major consequence will be found in changes to the dynamics of plate tectonics, which because of heat induction into the oceans according to the most recent evidence gleaned from the fossil records of ancient magma flow from the deep ocean ridges indicate. Once the arctic ocean is free of its ice grip upon the continental plates at the top of the world things really being to rock and roll... Of course, by the time it becomes evident that this is indeed the case it will already be too late. Maybe Google on something called the Siberian Traps.

 
At 7:55 AM, Blogger Binah said...

In restricting my comments to the north Atlantic, I was just being cautious. There's too much tendency to think that regional or local temperature trends necessarily reflect global trends.

That said, the up and down temperature trends in the north Atlantic are almost certainly connected with regional climate oscillations, the North Atlantic Oscillation and the El Nino Southern Oscillation, and probably have nothing to do with "global warming." See:

http://www.uwm.edu/~aatsonis/Global%20Temperature%20and%20El%20Nino.pdf
http://www.agu.org/pubs/crossref/2005/2005GL022875.shtml
http://www.sciencedaily.com/releases/2007/08/070801175711.htm

The fact that ENSO has been essentially shut off since the late 90s is a strong hint for a neutral-to-cooling global temperature trend in the last decade. That fits the surge in hurricanes during that same period.

 
At 12:30 PM, Blogger Lucky7Star said...

Look I wish to avoid making this post look like some sort of pissing contest the stakes are far too important and frankly because honest to god I pray that I'm wrong but another 7.9 quake in Indonesia seem like certain confirmation, however if you might try to avoid the obvious befuddlement of the mathematical data... Granted it's a bit complex but if you ask yourself a very simple question... Can you hold more heat in a mayonnaise jar fill with air or with water... Obviously water is the correct answer... Now the premise our weather is driven by simple atmospherics is just as ludicrous and so because it (El Nino that is) driven in nature by these simple atmospherics because its seasonal is also just as ludicrous. Try for a moment to consider if you have an electon particle stream that also reacts with the electromagnetic lines of force in a seasonal fashion as you do in fact with the rotation of the earth (if one thinks of the earth as being an electromagnetic dynamo for the electric inductor of solar heat). This would also explain a seasonal shift in El Nino as far back as 1925 (and beyond the time of the industrial age) actually much of this is outside of the simple man made effects of carbon dioxide gases but which the overall build up cannot simply be ignored from the fossil record, as ancient magma flows on the sea bed floor indicate. The point of all this is that we confront a problem of an extinction event... If it sounds hysterical, sorry but the "death knellā€of human civilization tends to bring that out... Especially if there is something we can do to stop it.

 

Post a Comment

Links to this post:

Create a Link

<< Home