East Pacific Hurricanes

[Ptarmigan]

I notice the East Pacific Basin is very active, one of the most active in the world. I read these hurricanes tend to form from tropical waves that form off of Africa. How come it is so active, yet the basin is smaller than Atlantic and North Indian Ocean?

[Aslkahuna]

Three words-North American Monsoon. There is an active monsoon trough that exists off Central America which helps in the development of those waves that make it across. Additionally, there's some very warm water off of Central America. The environment in terms of SST's, vertical shear, and horizontal shear is extremely favorable in the zone off the south coast of Mexico and thus this area has the highest per unit area rate of formation in the World. This is one reason why there's an inverse relationship between formation in the ATL and that in EPAC since when the ATL is active fewer waves get into this area of EPAC for development. Also, during La Niña episodes, the environment is less favorable in EPAC.

Steve

[Ptarmigan]

I notice in 1983, Atlantic was one of the least active, while West Pacific was below average. On the other hand, East Pacific was hyperactive, one of the most active on record. I know we were coming off a warm phase of a very strong El Nino, one of the strongest before 1997-98 and there was a lot of wind sheer for Atlantic. Any reasons for that?

[Mike Doran]

In the traditional sense monsoons are described as having to do with warm moist air rising into the mountains and cooling and then condensing--leading to phase change energies relative to the convective mass and driving the engine of the process, so to speak. Aslkahuna thinks this aids in formation of tropical storms although he doesn't explain why, nor address in detail the teleconnections issue with the Atlantic and even fails to address even as an issue the teleconnection issue with the Western Pacific, which is brought to his attention in the next post but is not met with a re-reply.

If you are going to use three words, I would use 'inverse distance relationship'. That's the kind of relationship that a static field has with distance. The farther something is away, the weaker the static field. One commonly understood area where this applies is with direct current applications like solar panels. If you place a solar panel more than 100 feet from your inverters, you can see as much as a 50 percent power drop. For the same reason, high voltage power lines which carry power over distances do not deal in 60 Hz AC you power everything in your house with--transformers take the cycles per second even to higher frequencies to carry the energy over distances better.

Anyway, so you have a problem losing your electrical power over distances. The tropical Americas including Central America and certainly south Mexico are places of mountains and then thunderstorms. You can call it the monsoon but before you get into the heat and pressure dynamics of that phenonmenon consider that those strikes then create displacement currents that do not have to move very fair to reach water with which an electrical coupling can occur--a capacitive relationship between the upper atmosphere and the ocean surface which are both conductive surfaces like any metal plated capacitor. And this coupling does occur. In the static field between the coupling, cloud microphysics are relatively altered. This produces warm and moist but non-convecting air--and opposite the monsoonal thunderstorms over the fair weather strip created by the displacement current is the ITCZ. The ITCZ basically is a cloudy region that takes advantage of the warm moist air because once that air comes under those clouds it become protected from the static field by the fact that water is a powerful dielectric and at the same time the couplings create zones of very positive upper atmospheric ions connected to negative ions on the ocean surface--which in turn creates on the ocean surface a region of relatively positive ions on the ocean surface. Opposites attract! Convection can then occur under the clouds without the electrics morphing cloud microphysics and once convection starts there are, of course, heat and pressure reasons for it to feedback more convection, including albedo reasons and movements of air vertically into colder masses that cause phase changes and relative contrasts of energy that brings about.

The teleconnetion issue is poorly addressed by modern meteorology without geoelectrics. The wave theory that Aslkahuna suggests is flat incorrect. Indeed the feature in the Eastern Pacific presently has little to do with any wave feature coming from the Atlantic and has much more to do with the fact that in the Western Pacific a tropical storm feature which WAS the low impedence region on earth fizzled and once it did then the local strikes in the tropical Americas could seek a more local low impedence target. And that region for this time of year is the EPAC. Essentially all we are waiting on now are favorable solar conditions for the storm to intensify into a more signficant storm. The relationship between Atlantic and EPAC is even more straight away--in that these basins share nearby sources of displacment currents and if one region has a lower impedence than another, the displacement current will flow in that direction at the loss to the other. It is true that from a dielectrics standpoint moisture from waves bears on these impedences, but fundimentally the relationship is more about electrics and not baratropics--there won't BE any moisture in waves if there are no electrics to create them. ENSO is a prime example of this where during El Nino the EPAC has relatively warmer AND THEREFORE MORE CONDUCTIVE waters in the region which lowers impedences. In contrast during La Nina in the EPAC the oceans are cooler and therefore the oceans are relatively less conductive there.

[x-y-no]

In the traditional sense monsoons are described as having to do with warm moist air rising into the mountains and cooling and then condensing--leading to phase change energies relative to the convective mass and driving the engine of the process, so to speak. Aslkahuna thinks this aids in formation of tropical storms although he doesn't explain why, nor address in detail the teleconnections issue with the Atlantic and even fails to address even as an issue the teleconnection issue with the Western Pacific, which is brought to his attention in the next post but is not met with a re-reply.

Uhhh ... no. That's not what a monsoon is nor how it is driven.

As for the whole electrodynamic hypothesis, it seems to me to be an elaborate idea with no empirical support in search of a problem. Sorry to be harsh, but you make a lot of declarations of fact that I see little or no support for.

[Mike Doran]

XYno,

BTW I am an ex smoker and very proud to have put the butts behind me.

Regarding the monsoon, Ben Cash, a climatologist (he was at Princeton now he's at Penn), and I debated the electrics a few years ago. We are still in touch over this debate--I spoke with him this winter for about an hour regarding the paper my father, a retired meteorologist, and I are writing on electrics. Ben wrote in 2002:

"Questions for Mike. Is there anything in the atmosphere that you _don't_ attribute to electrical mechanisms? Do you remember that you told me in a previous post that your mechanism doesn't apply over land?

In a nutshell, the monsoon is a continental-scale version of the sea-breeze phenomenon. During the summer months, the land warms much more
rapidly than the ocean, because water has a very high heat capacity. That is to say, more energy is required to cause a given temperature change in the ocean than in the land, and the land responds much more quickly to the stronger summer radiaton. Warm air rises over the land, and moist air is drawn in from the ocean to replace it.
This source of moisture, coupled with the rising air over the subcontinent, results in the torrential rains that characterize the monsoon.

This is, of necessity, a gross simplification of what is a very complicated natural phenomena. There are complex and poorly understood interactions between the low-level flow and the mountain ranges, as well as the latent heat released during the massive
convection accompanying the monsoon rains. But this is the basic mechanism."

"The ambient low will be near or south of the equator. The prevailing wind flow from the continent is from the NE flowing toward the SW. Since the flow is moving from mountainous land areas towards the sea, it undergoes heating as it moves to lower and lower elevations (increasing air pressure) and since there is no new supply of
moisture the relative humidity drops. The result is dry clear skies over
much of the Northern Indian Ocean. There is little or no electrical component to this.

Edit--moved quote down--these were Ben's words

During the summer monsoon the opposite occurs, the flow is from the SW to the NE (from the cooler sea towards to warmer land). As the warmer moist air is forced up the mountainside the air pressure decreases and the relative humidity increases until clouds form and the moisture is expelled as rain.

Let me throw something out there, too--a comment by Dr. Gray with no pun intended to get to a 'gray area'.


http://www.lavoisier.com.au/papers/arti ... canes1.pdf

William Gray presentation (p. 17):

quote:

"Small-Scale Problems. All sub-grid scale cumulus convection
parameterization schemes currently in use are poor approximations of
the real-world complex, non-linear small-scale convective processes.
The primary deficiency is the large amount of compensating up-and-
down motion occurring within the grid spacing that cannot be
calculated by the GCMs larger resolvable scales. These poorly-
resolved approximations of the sub-grid scale processes are then
integrated by the models for hundreds of thousands of time steps into
the future. This guarantees large errors. Realistic sub-grid scale
parameterization schemes have yet to be developed. Most GCM modelers
are unfamiliar with the detailed functioning of the hydrologic cycle.
Most research on the small scale parameterization of cumulus
convection in terms of the large scale was done in the 1960s through
the 1980s without satisfactory resolution. The topic was too complex
to be resolved during this period. To move forward the GCM models
primarily ignored this difficult task. They chose not to get `down-in-
the-trenches' on such a complex topic. They accepted a few simple
compromised schemes (with known problems) and went forward with their
broader scale modeling integrations assuming that their sub-grid
schemes were `good enough' or that the errors would average out in
the end. But the sub-grid scale approximations they have used are not
good enough and the multitude of errors does not average out. "

There are a couple of basic assumptions that Ben makes here that I take issue with. He starts out by asking if there was anything I didn't attribute to electrics--which is an entirely unfair comment. It's a complexity. IOWs an additional aspect of a problem to help understand what causes its dynamics. And basically the capacitive couplings occur over the oceans because salt water is about 1,000 to 5,000 times more conductive than land. Couplings THEN alter cloud microphysics and convective process rates. The seasonal assumption too does not look at the seasonal nature and extent of the ionosphere and how warmer SSTs with the season are also equally more conductive. And finally the assumptions regarding the uniformity of convective processes--essentially how air moves editsometimes in a non linear way/edit--is a largely unexamined area in the field of meteorology and climatology.

BTW:

http://www.utdallas.edu/nsm/physics/fac ... nsley.html

Brian A. Tinsley, Ph.D. page is here. This is the paper I like the most:

http://www.utdallas.edu/nsm/physics/fac ... nsley.html

Check out figure 2.1--very very good science. If you have a particular assertion that you take issue with, I have a huge book marked library of papers to support them. But without specifying what you take issue with, I would have difficulty fairly responding to you.

[x-y-no]

OK, you edited as I was composing a reply to your first version.

Regarding the monsoon, the description Cash provides is a good basic one. The point (regarding your earlier assertion) is that his explanation regarding airflow down mountain slopes and the resulting dry surface air is an effect, not a driving force of the monsoon.


Regarding Bill Gray's comment - that's part of his criticism of climate models (a piece of his broader criticism of anthropogenic global warming.) There are severe flaws in his criticisms which really aren't relevant to the topic of this thread but more to the point climate modelling isn't relevant to this thread so neither is this comment.


Finally yes, I'm familiar with at least some of Brian Tinsley's work although the stuff I know of has to do with cosmic ray and solar wind effects on upper atmosphere mostly but also ice crystal nucleation in cloud tops. I'm not aware (so far at least) of anything to do with ocean/air electrodynamic influence in cyclogenesis.

[Aslkahuna]

A Monsoon has absolutely NOTHING to do with mountains. A monsoon pure and simple is a seasonal reversal of windflow patterns and of mass and energy transfer. Monsoons can be wet or dry depending upon the origin of the monsoonal airmass. The NE monsoon of winter is very dry in parts of Asia. The monsoon arises due to the imbalance between the hemispheres (Northern and Southern) in terms of landmass distribution and thus seasonal heating and cooling. Cross equatorial flow characterizes the monsoon flow patterns particularly in Asia. As pat of the monsoon development, we have the Monsoon Trough which separates the Trade Easterlies associated with the Subtropical High which moves poleward in the Summer Hemisphere from the monsoon westerlies crossing the Equator (often mistakenly called the ITCZ which is something different-the convergence zone between opposing Trades of the two Hemispheres). Within the Monsoon Trough we find a region of lower pressure and low and mid level horizontal cyclonic shear couple with light vertical shear. This is a pattern which can lead lead to the development of low level vorticity and development of circulations. It's also a pattern that can enhance the development of tropical waves that venture into this region. Since development in this region does not depend upon Coriolis for initiation, it's easier to get both development and low latitude development here. The Monsoon trough associated with the Afro-Asian Monsoon will extend from the atolls SE of Guam into southern China and across SE Asia into northern Bangladesh and India into the Arabian Sea and thence across Tropical North Africa terminating just off the West Coast of Africa not far from the Cape Verde Islands during the Summer and early Fall. During the Northern Winter it's found from Tropical South Africa across the SIO and northern Australia and eastward into French Polynesia. The North American Monsoon Trough extends from the region of south coastal Mexico westward to about 140W and can extend into the SW Caribbean where it's a factor in storm development there. The warm SST's coupled with the very favorable dynamic environment results in the region being the most active in terms of initial development in the World though overall EPAC is the second most active region in the World. Despite what Messr. Doran says, I have explained this all a number of times before both here and elsewhere as well as on my homepage but it seems like every year I have to do it over again.

Steve

[Mike Doran]

I appreciate your explaination. Edit: I made a mistake by putting the computer quote programming too soon and some of Ben Cash's words appeared to be mine when they were his. I point that out because that is what I relied on earlier in defining what a monsoon is. And that is why I appreciate your comments even if they are at odds with a noted climatologist--experts do differ their opinions on things. There's an interesting paper by Trenbreth regarding defining ENSO and points out the struggle there is in this regard. Commonly, what something means and what professionals come to have it mean may be two different (or three and four different) things. After awhile then to say one thing causes another loses meaning because you don't define what causes what

But to the extent that it is a refutation of the complexity of electrics, it speaks it's own langauge. It's kind of like arguing with a bible thumper fundimentalism--when you hear the argument that the bible itself says its a final authority. And for that same reason we may end up talking past each other and learning NOTHING, but hopefully not. Certainly the speed of the spin of the earth differs as you move north and good old Coriolis comes into play BUT at the same time if there is a coupling the curving winds induct currents to the inside ring--and have electrical feedback meaning. I know you won't take my word for it, and that's okay, it's just that I hope I have the right to assert it here without getting called a crackpot or some other disrespectful slur. I believe that in time I will back up what I am saying with enough that there will at least be an admission of complexity of cause.

But to introduce a complexity over a well established area of science, I would expect no less skepticism. And I suppose the first place that you might object is to argue that there is no low frequency electrics going on inside a tropical storm when indeed there are (leaving effects for later). For that starting position--this recent paper is essential reading:


http://nova.stanford.edu/~vlf/publications/2005-04.pdf

Larger visual of Isabel as studied in this Stanford paper:

http://www.wetterzentrale.de/pics/atlight.jpg