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Heat Waves (4) A Climate Case Study:

By: Dr. Ricky Rood , 6:26 AM GMT on July 19, 2011

Heat Waves (4) A Climate Case Study:

In the last article I wrote that the extreme events of 2011 were providing us with the opportunity to think about climate and how to cope with a warming world. The U.S. is experiencing an extreme heat event this week (Masters @ WU). This heat wave is the consequence of a strong, stationary high pressure system over the central U.S., and it will move to the east over the next few days. Back on July 14th The Capital Weather Gang did a nice write up on the forecast of the heat wave. At the end of this blog are links to my previous blogs on heat waves and human health.

When thinking about weather, climate, and extreme events an important idea is “persistence.” For example, a heat wave occurs when there are persistent high temperatures. Persistent weather patterns occur when high and low pressure systems get large and stuck; that is, they don’t move. In the Figure below, you need to imagine North America and the United States. There is a high pressure center over the proverbial Heartland. With blue arrows I have drawn the flow of air around the high pressure system, and in this case moist air. There is moisture coming from the Gulf of Mexico and, in fact on the date when this was drawn, from the Pacific. This is common in the summer to see both the Gulf of Mexico and Pacific as sources of continental moisture.

Figure 1: Schematic of a high pressure system over the central United States in July. While generic, this is drawn to represent some of the specifics of 2011. The green-shaded area is where there have been floods in 2011. The brown-shaded area represents sustained drought in the southern part of the nation.

At the center of this high pressure system there is a suppression of rain, because the air is moving downward. This sets up a situation where the surface heats from the Sun’s energy. There is not much mixing and cooling, because of the suppression of the upward motion that produces rain. Hence, if this high pressure system gets stuck, then there is persistent heat. This is a classic summer heat wave.

Let’s think about it some more. There is lot of moisture being drawn around the edge of the high pressure system, and this moisture contributes to the discomfort of people. People – just a short aside about people: if we think about heat and health, then we are concerned about people’s ability to cool themselves. It is more difficult to cool people when it is humid because sweat does not evaporate. Suppose that in addition to this moisture, there is a region where the ground is soaked with water from flooding. Then on top of already moist air coming from the Gulf, there is local evaporation into the air being warmed by the Sun. If on the interior of the high, where the rain is suppressed, there is hot, wet air, then it becomes dangerous heat.

It’s not easy to derive a number that describes dangerous heat. But in much of the eastern U.S. a number that somehow combines temperature and humidity is useful. Meteorologists often use the heat index. It’s the summer time version of “it’s 98 degrees, but it feels like 105.” For moist climates, the heat index is one version of the “it feels like” temperature. Jeff Masters tells me that in Newton, Iowa yesterday, July 17, 2011, the heat index was 126 degrees F. (see here, and 131 F in Knoxville, Iowa on July 18)

Another measure of heat and humidity is the dew point; that is, the temperature at which dew forms, and effectively limits the nighttime low. The dew points in Iowa, South Dakota, Minnesota, and Wisconsin are currently very high and setting records. Here is a map of dew point for July 19, 2011.

Figure 2: Exceptionally high dew points centered on Iowa.

Now if I was a public health official, and I was trying to understand how a warming planet might impact my life, then here is how I would think about it. First, the Gulf of Mexico and the Pacific are going to be warmer, and hence, there will be more humid air. This will mean, with regard to human health for the central U.S., heat waves will become more dangerous, without necessarily becoming hotter. It is also reasonable to expect heat waves will become more frequent and last longer, because those persistent, stuck high pressure systems are, in part, forced by the higher sea surface temperatures. If I am a public health official here is my algorithm – heat waves are already important to my life, and they are likely to get more dangerous, more frequent, and of longer duration. But by how much? Do I need to know by how much before I decide on a plan for action?

If I think about the air being more humid, then I might expect to see trends in the heat index. I might expect to see trends in dew points, and trends in the nighttime minimum temperatures getting higher. (That’s where a greenhouse effect really matters.) I worry about persistent heat, warm nights, and the inability of people and buildings to cool themselves. I worry about their being dangerous heat in places where people and emergency rooms are not used to dangerous heat – not acclimated to heat – not looking for heat-related illness.

Let’s go back to the figure. Rain is suppressed in the middle of the high pressure system, but around the edge of the high pressure system it will rain; there will be storms. (see Figure 3 at the end) The air around the edge of high is warm and very wet. Wet air is energetic air, and it is reasonable to expect local severe storms. (See Severe Storm on Lake Michigan) And if the high pressure is persistent, stuck, then days of extreme weather are possible. If this pattern sets up, then there is increased likelihood of flooding. If I am that public health official, then I am alerted to the possibility of more extreme weather and the dangers thereof. But, again, can the increase of extreme weather be quantified? Do I need to quantify it before I decide on a plan of action?

Still with the figure - what about that region of extended drought and the heat from the high pressure system? Dehydration becomes a more important issue. As a public health official, I start to see the relation of the heat event to other aspects of the weather, the climate. I see the relation to drought. I see the flood, and it’s relation to the winter snow pack and spring rains.

So what I have presented here is to look at the local mechanisms of the weather – what are the basic underlying physics responsible for hot and cold, wet and dry – for moist air? If I stick to these basic physics, and let the climate model frame the more complex regional and global picture, what can I say about the future? Do I have to have a formal prediction to take action? Here in 2011, I see drought and flood and hot weather and warm oceans that interact together to make a period of sustained, dangerous heat. It does not have to “set a record” to convey the reality of the warming earth. It tells me the type of event that is likely to come more often, of longer duration, and of, perhaps, of greater intensity. If I am a public health planner, then I can know this with some certainty. The question becomes, how do I use that information in my planning?


Figure 3: Radar loop showing precipitation around the edge of the large high pressure system in the middle of the continent. July 19, 2011.

Previous Blogs on Heat Waves

Hot in Denver: Heat Waves (1)

Heat Waves (2): Heat and Humans

Heat Waves (3): Role of Global Warming

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

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well, if'n I could be world dictator... my off the top of my head ideas for the US of A:

1. Start with rationing fuel or simply raise the tax on fuel to around $3 per gallon with a 1$ per year increase after that. (Right off the bat I am not keeping the same standard of living but give me a transition period to get through and then return to our standard of living.) I'd do the same/equivilent thing with coal.

2. Require all factories, farms, mines, etc to meet pollution standards of zero runoff.

3. Increase junk mail costs, packaging costs and transportation costs on everything except personal movement. It's not good that my new TV is made in over there somewhere. Why isn't it made in Baltimore?

The goal of my little fantasy is:

1. Most transportation will done by electric bicycle, bicycle, skooter, eletric vehicle. Recharging for heavy vehicles is done by battery swap: i.e. join a battery club. If you need a battery, swap it out in a few minutes. Light vehicles can either recharge overnight/at work or have thier own private swap out system.

2. The charging power comes from mostly solar, wind, nuclear or wave power.

3. Note that the benefits of a light vehicle culture are far more than just the cost of oil. they include health benefits (no, really, look up the figures, it is amazing), less pollution, less infrastructure costs, and so on.

4. Insulation on buildings increases. For example, they have houses in Norway where breakfast cooking provides all the heat necessary for the entire day..in winter! Passive heating and cooling increases.

5. The US becomes locally self sufficient for most things. Things like maple syrup that are local can still be sent but are more expensive.

6. This still leaves manufacturing as an energy cost but I think it is a start.

The goal of my little fantasy is that we all are able to live the important parts of our lives the way we want. Those parts that are not important, like driving across town to buy a specific brand of ice cream (I just did this for someone) are lost.

I'd also like to see small towns and communities return and see telecommuting centers/internet community centers installed in them to provide local revenue required and provide that contact with the larger society that is required.

I know it is a fantasy but without writing novels, that is my best attempt at describing the transition method and the goal. Imagine waking up and breathing clean air, being debt free and being able to walk (bike) to a downtown of a community that you know and care about. I think it is worth fighting for.

Member Since: December 31, 1969 Posts: Comments:
Ok so what are your ideas Green I am open to any.
Member Since: December 31, 1969 Posts: Comments:
Quoting nymore:
I would like to know if anyone has any concrete ideas how we can stop pollution and still keep our standard of living.

My brother! Many are the answers.

The key is that 'standard' does not equal 'same'. For example, having a small economy car instead of a large 4x4 would be the same 'standard' to most people in the world. It is not the 'same' however.

In my definition of standard, I have good clean air, water, land and sea. I have freedom to vote, to do what I want (so long as I don't pollute or brak other community standards), to live my life how I chose. I have a country that is financially stable and corruption free. I have freedom to travel, freedom of speech, etc.. I have my house, I have air conditioning on the really hot days, I have a huge refridgerator and heat in the winter. I enjoy foods from around the world and my kids are raised in a safe environment.

If your definition of standard includes driving heavy cars, buying products made by companies that can't compete without polluting, etc., probably not.
Member Since: December 31, 1969 Posts: Comments:
Also notice the land temp anomaly map notice how the blue goes away in some locations and are replaced by red then look down by the Sandwich Islands the anomaly is 5 C but the water temps are colder than normal but the anomaly stays at 5 C how could this be possible. I could be wrong but something seems wrong with the graphs.
Member Since: December 31, 1969 Posts: Comments:
When I look at the temperature anomaly graphic posted by Cyclone something strikes me as odd. Look in the Pacific, notice in the equatorial area NOAA has is between either 1 or 2 C above normal while no other sea temp anomaly map I can find shows anything like this. Could it be a warm bias in the graph this seems to happen at other locations too. The others show a warm anomaly near South America but nothing extending out into the Pacific
Member Since: December 31, 1969 Posts: Comments:
Interesting link from Taz Link not sure how much stock to put in this
Member Since: December 31, 1969 Posts: Comments:
JBastardi- It is more than likely true the cattle up north are not used to that kind of heat. Example I am from northern Minnesota when we work down south the northern boys don't do well with the heat and by the same token when we work up north the southern boys don't do well with the cold
Member Since: December 31, 1969 Posts: Comments:
Thanks Pat but solar panels use toxic minerals (metals) that we have to mine creating ground water and other enviromental pollution
Member Since: December 31, 1969 Posts: Comments:
Des emplacements tres bons pour un novice pour apprendre comment la Science fonctionne et des donnees est dissemins.

National Climate Data Center

NOAA National Operational Model Archive & Distribution System

The NOAA National Operational Model Archive and Distribution System (NOMADS) is a Web-services based project providing both real-time and retrospective format independent access to climate and weather model data.
Member Since: December 31, 1969 Posts: Comments:
The DESERTEC Concept

The DESERTEC Concept was developed by a network of politicians, scientists and economists from around the Mediterranean, from which arose the DESERTEC Foundation.

Choosing the best locations offers the greatest benefits in fighting global warming
A final switch towards renewable energies will, with high probability, be a combination of global and local, centralized and decentralized approaches integrating all forms of renewable energies. But when it comes to combating global warming, the leverage of investment in renewables is greatest when the best sites are used. Plants in these locations can produce more clean energy than those in less suitable sites.

This is why the basic idea of the DESERTEC Concept is to generate electricity from renewable sources at the places where they are most abundant. A high-voltage direct current grid carries the electricity generated from renewables over long distances with a minimum loss of power, making it available wherever it is needed. This can provide the world with an economical, safe and sustainable supply of clean electricity.

Energy is available in abundance and we have the technology to use it

Within six hours, deserts receive more energy from the sun than humanity consumes within a year. The sun shines all day on a belt that encompasses the globe either side of the equator – and with the technology that is now available, most countries could supplement their energy mix with clean electricity from deserts. Thanks to heat storage tanks, solar-thermal power plants in deserts can supply electricity day and night, ideally supplementing electricity grids that rely on fluctuating energy sources such as photovoltaic and wind power.
Member Since: December 31, 1969 Posts: Comments:
I would like to know if anyone has any concrete ideas how we can stop pollution and still keep our standard of living.
Member Since: December 31, 1969 Posts: Comments:
Quoting DARPAsockpuppet:
I don't think it's a coincidence that the Rolf-Dieter Heuer sent out the 'scientists not allowed to interpret data' memo on this CLOUD experiment because nearly all CERN scientists agree with him on AGW, so they'll go along with it, but they ought to realize that a precedent will be set here one way or the other and that if they let Rolf-Dieter Heuer start selectively dictating what data scientists are allowed to interpret or not then the next Director General will have that power also. They ought to draw a line in the sand or whatever the soil composition is in Geneva, stand their ground, and say "NO!, Mr. Director General, you cannot muzzle us! We are the most esteemed scientists the world has to offer and we find it highly offensive that any Director General would ever attempt to take away our power of thought no matter what the issue! We will continue to interpret all the data and if you want to fire us over doing what is in our job description we'll see you in court."

Here we are again, huh?

Please listen: Heuer didn't send out any "scientists not allowed to interpret" edict. Rather, he asked the CERN scientists connected with the CLOUD project to present the results of that project without any public interpretion of those results until the paper is published. Period. Nothing wrong with that. Nothing evil. Nothing shady. Nothing manipulative. No muzzling, no silencing, no cover-up. Just a project manager wisely asking his team members not to unintentionally sabotage the results of a very complex project dealing with a hugely complex subject by prematurely discussing the results without the proper documentary evidence.

Not that it ultimately matters, of course; if the results undermine AGWT, denialists will point fingers at Heuer for his criminal behavior. If the results are neutral, denialists will demand to know why Heuer insisted on silencing his team. And if the results support AGWT (which they almost certainly will, as all current science does), denialists will say it's false and phony and just another part of the scientific plot to take over the world.


Seriously, people need to stop gullibly swallowing every little nugget of swill emitted from WUWT and others of the sort. At the very least, they should apply a few critical thinking skills while reading, and maybe toss in a little research. It wouldn't hurt...
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Dr. Ricky Rood's Climate Change Blog

About RickyRood

I'm a professor at U Michigan and lead a course on climate change problem solving. These articles often come from and contribute to the course.

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Clouds in the lee of the Rockies at sunset.
Clouds in the lee of the Rockies at sunset.
Clouds in the lee of the Rockies at sunset.
Clouds in the lee of the Rockies at sunset.