Stormy World

"If it forms into a hurricane, it may become one of the very rare Atlantic hurricanes in the Southern Hemisphere"

I doubt it. Hurricanes don't cross the Equator. On the other side the Coriolis force works in the opposite direction.

The hurricane that crossed the equator a few years ago spun counter clockwise. It did form north of the equator (and this one is also north of the equator, barely). Its just that last time I checked the winds were likely to push it south. Haven't checked in a while, though.

Ack, no, it is moving WNW at present.

Hurricanes don't cross the Equator. On the other side the Coriolis force works in the opposite direction.

Actually, it is rare for hurricanes to form near the equator, because there the Coriolis force tends to convert east-west motion into vertical motion and vice versa (north-south motion is not subject to Coriolis force at the equator because that component is parallel to the angular velocity vector), and the vertical component of Coriolis force is usually negligible compared to gravity. In this case, proximity to the South American coast is also an inhibiting factor. Nothing prohibits a blob from forming on one side of the equator, crossing it, and then developing into a tropical cyclone. For a tropical cyclone to form on one side of the equator and cross to the other side would take some exceptional circumstances--Greg, do you have a link for the tropical cyclone which you claim @2 actually did that?

It really happened. It was a couple of year ago, and it may have been a later season storm, the year we went into alpha names. When I get a chance I'll look it up.

I remembered it wrong. It did not form in the north and go south, it just formed in the south and there it was:

http://en.wikipedia.org/wiki/Cyclone_Catarina

It hit Brazil.

Thanks. I knew about Catarina; I just wondered whether there was some Pacific or Indian Ocean storm that did that.

Wikipedia lists a total of seven tropical cyclones in the South Atlantic. Catarina is the only one so far to reach hurricane strength; there have also been four tropical storms and one tropical depression (they do not give a maximum strength for the 1974 cyclone). That includes TS Anita in March of this year, the first South Atlantic storm to be given an official name (Catarina is an unofficial name).

'Is this all caused by Global Warming? Yes, probably.'

Ah, definitive speculation. The best kind of speculation in my opinion.

'Instead, we increasingly recognize that the energy balance sheet has shifted (are my metaphors mixing?) and we live in a stormier world now than we did 100 years ago, because of the release of carbon trapped in antiquity into the atmosphere.'

Back to the definitive statements there are no way to prove. I would personally like to see the data that says we live in a stormier world given the fact that WMO has said there is no such trend in tropical storms, http://www.nature.com/ngeo/journal/v3/n3/pdf/ngeo779.pdf As far as I understand, and I would appreciate being proven wrong on this point, there is no such time trend in tornado formation, droughts or other 'extreme weather' events.

It is indisputable that excess CO2 in the atmosphere causes an increased greenhouse effect and some amount of warming in response. Also, that CO2 excess is there due to human efforts.

Whether or not that increased greenhouse effect manifests itself as changes in frequency in large storms like we've over the Midwest this week is much less understood. To promote such a position is neither scientific nor logically sound. With the data we have available, we have to accept the null hypothesis rigorously that such an effect does not exist.

A scan of all lat data for the Eastern N. Pacific shows the closest measurement to the equator is 4.2 deg. That's pretty close, and depending on the time of year, must be pretty close to the ITCZ! The minimum for the Atlantic is 7.2

The max is 69 in the Atlantic, by the way! That was Alberto in 2000, which remained as a tropical storm in the Atlantic between northern Newfoundland and Plymouth, but was tracked as an ET much farther north. (The archive has it at 70.7degN but the NOAA data file omits that last point)

Maxwell: "higher resolution modelling studies typically project substantial increases in the frequency of the most intense cyclones, and increases of the order of 20% in the precipitation rate within 100 km of the storm centre.

There remains a lot of uncertainty as to what this all looks like. Storm intensity and other patterns operate, clearly on el-nino level cycles, and one cycle can be different from another. This places us in the situation where three or four cycles would be needed to be sure of the nature of the pattern of some weather patterns. This, the, places us in the situation of needing similar ranges of data in the past, which can limit our information, say, for small tornadoes in regions with less data going back decades.

However, the balance of new research is increasingly indicating that what I say here is the case.

I'm going with the combination of the nature of the physics and the meteorological system combined with increasingly positive indicators of increased storm data.

You, if you like, can go with the "until a hundred years of data are available and analyzed for the next hundred years, we should sit on our hands" approach.

The null hypothesis is not that energy does not relate to weather. That's just dumb. The null hypothesis is that energy increase means more energetic weather. The detailed nature of that is not clear, of course.

My point is not that a given storm is caused by a given SUV beltching CO2 into the atmosphere. My point is that the proper answer to "is this storm bigger, or does this storm exist, because of AGW" is not "We can't say that."

The proper answer is "That is not a valid question because it ignores the nature of the system and the nature of causality. Rather, ask if we will live in a stormier world if there is more energy retained in the atmosphere, as has happened with AGW."

Ask that question, the answer is "yes."

The explicit claim, scientific or not, is that we are stormier now than 100 years ago because of an increased greenhouse effect due to excess CO2 emitted by people.

'...we live in a stormier world now than we did 100 years ago, because of the release of carbon trapped in antiquity into the atmosphere.'

The null hypothesis to this claim is that there is no such effect between an increased greenhouse effect and 'storminess'. Given the explicit claim you made, that is, by definition, its null. Based on the real world, observational data, you can't reject the null hypothesis. I don't think there is much room for debate on that.

More troublesome,

'The null hypothesis is not that energy does not relate to weather. That's just dumb. The null hypothesis is that energy increase means more energetic weather. The detailed nature of that is not clear, of course.'

where you're not really making any kinds of observable claims. What does 'more energetic weather' mean operationally? Does a week of marginally higher winds equal a day of highly anomalous winds?

All of this seems more or less vague enough to pass certain validity tests, but not much else. So the notion of 'null hypothesis' doesn't really mean anything in this context. If you are willing to make a claim we can test, I'd be happy to discuss how we assess it observationally with you and what its null might be.

The other aspect of your statement, 'energy increase', is not really true either. An increase in the greenhouse effect does not increase energy. It slows the earth's ability to cool itself. So one just has to integrate over a longer period of time to get rid of the same amount of sunlight.

As you state above, all the energy used for weather comes from sunlight. If we're arguing that the amount energy coming from the sun is staying about the same, then there isn't a substantial increase in energy. So thinking in those terms isn't correct.

Energy from the sun is around longer due an increased greenhouse effect, which may or may not lead to more storms. As of right now, it has not done so historically.

The other aspect of your statement, 'energy increase', is not really true either. An increase in the greenhouse effect does not increase energy. It slows the earth's ability to cool itself. So one just has to integrate over a longer period of time to get rid of the same amount of sunlight.

In case anyone wanted to know whether maxwell was being pedantic or denialist, that's the paragraph to pay attention to. As misstatements of systems go, it's the equivalent of a creationist trying to lean on entropy moving in the "wrong direction" because local organization increases. maxwell just does it backward: there's no increase in energy within the local system being discussed (Earth weather) because there's no increase in energy within the greater (solar) system.

The rest of the comment is mostly, "This one statement is wrong because you didn't write a different blog post or do your own experiment instead of summing up the current understanding of climate."

Not pedantic, wrong and so denialist. The greenhouse effect does increase energy in the atmosphere. By two mechanisms.

The greenhous effect causes higher temperatures, increasing energy content by heat capacity times temperature.

Higher temperatures also increase the vapor pressure of water increasing energy content by the heat of vaporization of the increased water in the atmosphere.

Stephanie,

given the fact that the statement of mine you highlight is basically a re-iteration of Greg's checking account example in the post above, I'm going to chalk up your 'analysis' to an inability to deal with criticism, constructive or otherwise. I also find it funny that you can take the position of someone who wrote

'It is indisputable that excess CO2 in the atmosphere causes an increased greenhouse effect and some amount of warming in response. Also, that CO2 excess is there due to human efforts.'

and claim he is 'denialist'. Try working a little harder for your point next time...

daedalus2u,

your statement concerning heat capacity is really non-sense. The temperature of any material system changes in response to adding or taking away energy. Changing the temperature doesn't change the energy. You have the cause and effect relationship reversed.

Moreover, the sun gives the earth energy in the form of light in the UV, visible and near infrared light. That energy gets distributed in different physically processes on earth, weather being one of them. The earth does this because the space around our planet is at a much lower temperature. Therefore, energy will flow to space due to the second law of thermodynamics via radiative pathways mostly.

The main point, however, is that energy must be conserved and cannot be created out of thin air. If energy is absorbed by CO2 molecules and re-emitted back toward earth as is the case for a greenhouse effect, that energy didn't just show up on earth. It came from the sun via sunlight. Therefore, since the energy necessary for all radiative and non-radiative processes on earth (weather and the greenhouse effect included) comes from sunlight originally, an increased greenhouse effect DOES NOT change the amount of energy involved in earth system in any way. It simply redistributes the energy that's already here.

Max, I made a claim, I did not state a hypothesis, so defining my null hypothesis is mere sophistry. Not helpful.

My objection to your earlier attempt stands: With increased energy in the atmosphere there will be increased energetics of the atmospherics. We are now starting to see both models and empirical studies showing this. The paper you cite in an effort to discredit my post is an example of a paper that cites positive evidence in models and data of increased activity, but also correctly points out that it is complicated and hard to characterize so far.

"So the notion of 'null hypothesis' doesn't really mean anything in this context. If you are willing to make a claim we can test" .... that was you making the claim of a hypothesis, not me.

New hypothesis:

"The other aspect of your statement, 'energy increase', is not really true either. An increase in the greenhouse effect does not increase energy. It slows the earth's ability to cool itself. "

You didn't read my post, did you? I stop here. Prove to me you read the fucking thing and I may let you continue to comment.

Maxwell, the amount of energy in the atmosphere and oceans is increased with global warming. It is not true that the energy is not increased but just stays around longer. Laden's model is correct, but your use of it is flawed.

Consider this: The temperature of something is higher when there is more (heat) energy. More heat energy = higher temperature. (just stating it two ways) In this case it is the atmosphere and oceans. One could substitute the word "increased energy" for the word "warming" and thus "global warming" reads "global increased energy." Not at all difficult to get when put that way.

maxwell, I don't care what you "chalk it up to". Pretending you know why someone is pointing out that you're wrong doesn't make you right.

Weather is atmospheric disturbance, so in a sense weather is energy. It is a combination of kinetic energy (air movement) interacting with friction, et and, obviously, simple heat which interacts differentially in moist (vapor rich) vs dry air to produce the interesting effects we watch the TV news to learn about every day. Adding heat to the atmosphere by definition increases weather, and heat is certainly added because the alternative pathway of radiation is reduced. How this plays out may well take a while to understand meaningfully, but no one seriously doubts it.

The northern European/British storminess data would be definitive were it not for the fact that there are also blips in the past of very stormy decades. This may be a matter of sorting out the causes better, but for now that data set can be used to argue for a steady increase in storminess over the last several years, and an increase in the 1910s or 1920s, one caused by increased atmospheric temp, the other by something else.

The fact that this data (storm frequency and intensity) is very messy gives denialists a lot of leeway. The increase of "weather" is simple physics. The nature of that weather mostly TBD.

maxwell: a number of dead physicists just spun in their grave on hearing of your explanation of heat, energy, the earth's atmosphere, and such. You are making a creationists thermodynamics argument but for the earth's climate. Yessir, the way in which the energy is distributed changes. Specifically, enough of it stays in the system longer to have large effects, the most directly measured and obvious being an increase in the average temperature of the atmosphere and the oceans.

Greg,

the paper I cite explicitly points out there is no statistically significant increase in tropical storm frequency or intensity in the historical observational trends. If there are some other papers that dispute that finding, I would be interested in reading them.

'My objection to your earlier attempt stands: With increased energy in the atmosphere there will be increased energetics of the atmospherics.'

Again, you state in the post itself, in no uncertain terms,

'Your paycheck is automatically deposited every two weeks (that's energy from the sun) and varies only a little from time to time.'

If the energy entered into the system isn't changing or changing 'only a little', where is the 'increased energetics' coming from? You can't make energy from nothing. It's just around longer, as you have already pointed out. That's not 'extra' energy. It's energy that would be there under all scenarios. And so the question becomes what does that energy do before it's emitted out to space over a longer period of time?

It could lead to more storms. It could not. Again, given the data we have, all we can say is that there is no historical increase in the frequency or intensity of storms.

'Prove to me you read the fucking thing and I may let you continue to comment.'

Do I get a practice quiz before the real test?:)

Everyone else, I'm very impressed with your ability to confuse a real argument with insults. As a physicist, I especially like the comments alluding to my knowledge of physics. Those are classics.

Maxwell, I'm surprised you are a physicist. I'm not sure I believe that.

Let's make it simple. Let's say a unit of the sun's energy is a truck. The sun, instead of raining down photos, rains down trucks. Most of the trucks land on the equator, and then drive to the poles. Trucks driving along ... that's the weather.

Now imagine two versions of the earth's system. In one version, half the trucks drive all the way to the poles, and half the trucks, after landing on the earth, float back to the outer atmosphere and evaporate pretty much right away.

In the second version, one hundred percent of the trucks drive to the poles, then 'dissipate'

You see, the energy does not go away. It is conserved. You know that. But the energy can be one place or another, on place being in the atmosphere. If energy does not leave the atmosphere it can participate in the weather system, if it leaves the atmosphere it can not.

The idea that added energy (reflected in increased measured temperature) increases weather activity somehow, somewhere, somewhen is the expectation based on the physics.

I think I know where some of this confusion is coming from.

I think that 'the earth' and the 'lower troposphere' are being used as synonyms for one another in this discussion. In the case of the lower troposphere, I agree, an increased greenhouse effect will increase the amount of energy in the lower troposphere. Possibly dramatically.

I think that the situation in which we deal with the lower troposphere is totally analogous to having two boxes filled with molecules. Each box can interact with the space around it, but one of boxes has a layer of insulation that slows its exchange of energy with the surroundings. If we keep adding energy, via any mechanism, to both boxes at the same rate, the box with insulation will not be able to dissipate the energy to its surroundings as quickly as the uninsulated box. The insulated box will increase in temperature with respect to the uninsulated box (assuming we're adding energy at a rate larger than dissipation in both boxes). That increase in temperature is a direct result of an increase in energy relative to the uninsulated box.

I think this is the point that daedalus2u was trying to make and I apologize for calling such thinking 'non-sense'. Clearly I was picturing something else and should not have used that kind of language. That basic physical understanding is of good utility in modeling the specific case of the lower troposphere.

Alternatively, if we want to project our box analogy onto the whole atmosphere, things get dicey. That's because the molecules in the atmosphere are under a gravitational potential which creates a barometric distribution of densities. That is, at lower altitudes, the density of molecules is higher than at higher altitudes. This barometric distribution of densities creates layers in the atmosphere that behave differently than the lower troposphere.

Now, when greenhouse gases in the lower troposphere absorb IR light given off by the earth, they are effectively closing the window on energy pathways to higher layers in the atmosphere. So while the greenhouse effect heats the lower troposphere, it COOLS higher layers of the atmosphere because energy is not getting to those layers as easily or readily. Because the higher altitudes are still dissipating energy out to a much colder space surrounding the earth, these higher altitude layers must decrease in temperature.

So not only does the greenhouse effect cause warming in the lower troposphere, it creates an energy stratification in altitude in the atmosphere. It is this gradient of energy that helps create weather. Energy 'wants' to get out of the earth system and does so through convection of warm air to higher and higher latitudes and altitudes. This is part of the reason why we have specific weather patterns that form at specific times of year in specific places.

Does the energy difference between layers of the atmosphere mean that there is no net energy being added to the whole earth system (all layers of the atmosphere) by an increased greenhouse effect due to human emitted CO2? Almost exactly, in fact (http://www.cgd.ucar.edu/cas/abstracts/files/kevin1997_1.html). The energy into the earth system (all layers of the atmosphere) is balanced to energy out of the earth system to within 1% EVEN IN THE PRESENCE OF AN INCREASING GREENHOUSE EFFECT. I will claim that more precise satellite measurements will get this number closer to zero rather than farther from it. The error in the measurements involved is as large or larger than the measurements themselves. Since satellites measurements have only been done in the past 30 years, we also don't know what the energy balance 'should be' without human induced warming. It may be positive (very small amounts of energy added to things like life) naturally.

Will an increased greenhouse effect due to human emitted CO2 cause a bigger difference in temperature between the lower troposphere and higher altitudes? Yes, but the magnitude of that change in temperature difference is likely not a well-known number.

Will that larger temperature difference due to an increased greenhouse effect cause more storms? Maybe, but it hasn't yet.

Maxwell, that's probably a pretty good description and model of how it can work, but there are few problems. For one, despite the claim you make that the energy in the system will be the same with or without changes in geenhous gases, the atmosphere and the ocean nonetheless have more energy in them. Heat is a form of energy. It is measured by temperature. There is more of it. So you'll need to adjust your model to account for that.

"Will an increased greenhouse effect due to human emitted CO2 cause a bigger difference in temperature between the lower troposphere and higher altitudes? Yes, but the magnitude of that change in temperature difference is likely not a well-known number. "

This is a good question, and it is important, but you have to add something: There is also the movement of energy from tropical regions to polar regions. The surface to space gradient is what sets up some aspects of the pattern but most actual weather outside of the ITCZ is shaped by the equatorial-polar transfer.

"Will that larger temperature difference due to an increased greenhouse effect cause more storms? Maybe, but it hasn't yet. "

I will fix that sentence for you:

"Will that larger temperature difference due to an increased greenhouse effect cause more storms? The physics say it must, but since the variation in "storminess" is a) large and b) when periodic, periodic on decadal scales and c) proxies for storms are ambiguous and otherwise suck so historical data is limited so far, it hasn't become an in your face statistical signature yet but we are expecting it to do so. Furthermore, referring back to the point of the post above, when someone says "is this storm caused by global warming" the proper answer is to insist that the question be rephrased to something like "can we expect greater storminess in some systems and regions with increased heat and moisture in the atmosphere caused by agw?""

Greg,

I still there is a language issue here. You say,

'For one, despite the claim you make that the energy in the system will be the same with or without changes in greenhouse gases, the atmosphere and the ocean nonetheless have more energy in them.'

I would say, yes, the ocean (as an actor with the lower troposphere) definitely has more energy in it, but that your term 'atmosphere' is still ambiguous. You mean the lower troposphere. As I already pointed out, an increasing greenhouse effect will DECREASE the temperature of higher layers of the atmosphere, most famously the stratosphere. That decrease in T is due to a decrease in energy because more energy is lost to space than is received from the lower portion of the atmosphere.

So I still stand by my claim that, as a whole, the atmosphere is very close to being energy balanced, even in the presence of an increasing greenhouse effect as satellite shows to some degree of precision. Whether or not that point matters in the context of 'storminess' is worth investigating, but I hardly see how, in the way I am framing it, you can contest this notion given the data.

Also,

'This is a good question, and it is important, but you have to add something: There is also the movement of energy from tropical regions to polar regions.'

was something I had touched on in my previous comment, where I state,

'So not only does the greenhouse effect cause warming in the lower troposphere, it creates an energy stratification in altitude in the atmosphere. It is this gradient of energy that helps create weather. Energy 'wants' to get out of the earth system and does so through convection of warm air to higher and higher LATITUDES and altitudes.' (I put an emphasis in there)

How an increased greenhouse effect would manifest itself in polar motions is still unknown as well, though I imagine it will have an effect of some magnitude.

I still don't understand how you can make statements like,

'"Will that larger temperature difference due to an increased greenhouse effect cause more storms?" The physics say it must...'

however. All the physics says is that there will be a flow of energy from higher to lower states, as posited by the second law of thermodynamics. Those basic physics do not necessitate the formation of large system of low pressure in the form of a hurricane, land or otherwise, in order to flow energy out of the earth system. That formation might happen anyway, but it's most definitely not necessitated in any meaningful, a priori way.

With more energy in the lower troposphere, there might a significant sheer wind signal that would reduce the number of Atlantic tropical storms and hurricanes. I don't think there is any definitive way to say what will happen right now.

I would be interested in knowing what you think a 'signal' in the tropical or other large storm time series would be though. Would it be one more 'large' storm per decade? Or per 5 years? If that signal is going to come out of the noise, what do you think a 'meaningful' signal is going to look like?