Atmo.Sphere

Ozone days on going (in Houston)

barry_lefer — Thu, 27 May 2010 02:42:00 GMT

I have been in California for the past week measuring air pollution in Pasadena and have been impressed with the amount of pollution from cars out here. We are not only measuring the pollution but all the meteorology that results in the "bad" pollution days. Today was an overcast day and we did not make that much ozone, but over the past week we have had very high levels of aerosol particles in the air. High enough that I coud not see the San Grabriel Mountains only 7 miles away. Last friday we also installed an ozone pollution and solar UV monitor on top of these mountains at the Mt. Wilson Observatory (alitude of approximately 5,700 ft or 1500 m), which is usually above the surface pollution layer. The problem here is that light winds from the ocean carry Los Angeles pollution towards Pasadena where it gets trapped by the mountains. If Houston had mountains we would have even more ozone pollution days.

So the good news for Californians is that so far clouds and winds have worked together to prevent the high ozone from forming here over past couple of weeks. Unfortunately, the hot, still, and sunny weather behind the last frontal passage has resulted in the unwanted conditions that result in high ozone in Houston. Today our monitors at the University of Houston main campus measured over 125 ppbv of ozone this afternoon, these are levels that are unhealthy for all Houstonians. The red curve in the figure below is 5 min averaged of ozone, the blue curve is 8-hr averaged ozone in parts per billion.

The bad news is that looks like tomorrow (27 May 2010) is also going to be a day with unhealthy levels of ozone. I would recommend checking the following websites:

http://www.tceq.state.tx.us/cgi-bin/compliance/monops/select_curlev.pl?region12_cur.gif#map1

http://www.hnet.uh.edu/location/index.php?location=1

to see what ozone levels are before exercising or spending too much time outdoors after 11 AM. Fortunately we only have 10 - 20 days per year like this, just so happens that today, tomorrow, and perhaps Friday will likely have "bad" ozone for parts of our metropolitan area.

Next week I should have more to report about what we are learning out here in California and some results from my graduate students measuring the ozone happening right now in Houston. Be careful the next couple of days and then relax and enjoy the rest of the summer.

California Air Quality Problems

barry_lefer — Mon, 10 May 2010 04:23:00 GMT

John Nielsen-Gammon has done an outstanding job as the sole contributor to Atmo.Sphere and I quite impressed with John's new blog ClimateAbyss (http://blogs.chron.com/climateabyss/). He is just as busy as I am, yet he manages to post something every day. While I cannot fill John's shoes, as the former honorary associate blogger for Atmo.Sphere, I am happy to try to pick up the slack and cover our Atmosphere at least a weekly basis.
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For my first post (in the post jng era) I wanted to talk about the CalNex-LA project my students and I are participating in May 7th to June 20th, 2010. Contrary to public perception, Houston is not the air pollution capital of the US. That dubious honor has been firmly held by Los Angeles, CA since the passage of the 1970 Clean Air Act Amendments. Houston did gain some notoriety in 1999 when we had a few more ozone exceedance days than LA did, but that was a temporary blip on the radar. For me, the exciting news is that Houston ozone pollution has been reduced significantly over the past five years, in a large part due to NOx reductions from several large electric powerplants in our area. And even in 1999, I would have argued that LA had much higher particulate pollution levels, which are just as harmful as high ozone. Certain neighborhoods in Houston and SE Texas near petrochemical facilities likely have high levels of certain air toxics, higher than my be found in LA, so Houston is not completely off the hook. But this is a topic for a future blog.

So one question you may be asking is: Why have the National Oceanic and Atmospheric Administration (NOAA) and the Air Resources Board (ARB) of California teamed together to conduct a month long study of the Air Quality of southern California. Haven't we studied the pollution in LA enough? The short answer is: Despite all the previous work, there still remain significant gaps in our understanding of air pollution. Scientists has known for a long time that LA is good at making pollution because as the second largest metropolitan area in the US with approximately 13 million, a very large shipping port, several oil refineries/chemical facilities, and the Santa Gabriel MOUNTAINS to the east. The sea breeze carries pollution from the Pacific coast and then the mountains on the eastern side of the LA basin efficiently trap the these emissions and makes high levels of ozone and particulate matter. Houston is fortunate to be on a very flat plain where are pollution can easily waft away downwind.

Even though California has some of the strictest and well-enforced air pollution regulations in the US, LA still has a significant ozone and particulate aerosol problem. Consequently the policy makers in California and at EPA need good data on the current state of air pollution in order to make informed decisions. One of the questions I have is why isn't LA air pollution cleaning up? New research from NOAA scientists suggests that air pollution from Asia is traveling across the Pacific Ocean and contributing to "background" ozone pollution. This makes a lot of sense, but in order to confirm the importance of the transported pollution, scientists need to measure how much ozone and particulate matter is home grown in LA.

As I noted above Houston ozone pollution has improved significantly, BUT it is still unacceptably high. The EPA has a complicated way of calculating the ozone "design value" for a particular city, but the bottom line is Houston still has more than 10 days each year above the 85 ppbv 8-hour averaged ozone. Later this summer, probably in August, EPA will announce the revised ozone standard, very likely to be 65 ppbv or 70 ppbv for an 8-hour average. When this happens, Houston will have 30-40 days each year where some part of our metro area will experience unhealthy levels of ozone. Why is EPA tightening the ozone standard and making it such that some 60+ counties in Texas will be in "non-compliance" with the Federal Clean Air Act? Short answer is that many studies and health experts suggest that exposure to 85 ppbv ozone causes serious negative health effects and that lowering ozone standard to 65 ppbv would better protect all US citizens. I have rambled on quite a bit here. Hope to cover many of these topics in future posts.

Over the course of the next 4 weeks or so I will be blogging about how the CalNex-LA and related field campaigns are going. In particular I will focus on what we have learned so far and how this knowlegde may help us better understand how to improve Houston air quality. Below are a few links to websites related to the CalNex project and a list of the CalNex science objectives:

http://www.esrl.noaa.gov/csd/calnex/
http://cires.colorado.edu/jimenez-group/wiki/index.php/CalNex-LA
http://www.arb.ca.gov/research/fieldstudy2010/fieldstudy2010.htm

Emissions

1. How can we improve the emissions inventory for greenhouse gases, ozone and aerosol precursors including emissions from soil, ships, agriculture and other non-industrial or transportation related processes? What measurements can help validate the use of satellite data for biogenic VOC and NOx emission inventories?

2. What emissions (natural and anthropogenic) and processes lead to sulfate formation over California coastal waters and in urbanized coastal areas? What is the contribution from ship emissions? How does Southern California compare and contrast with the San Francisco Bay Area?

3. What sources and processes contribute to atmospheric mercury concentrations in California?

Chemical Transformation and Climate Processes

1. How important are chemical processes occurring at night in determining transport and / or loss of nitrogen oxides, reactive VOC and ozone? Do regional models in California adequately represent these processes and their effect on air quality?

2. What are the sources and physical mechanisms that contribute to high ozone concentrations aloft that have been observed in Central and Southern California?

3. Are there significant differences between Central Valley and South Coast Air Basin precursors or ozone formation chemistry? Will meteorological and/or precursor differences between the Central Valley and the South Coast Air Basin lead to different chemical transformation processes and different responses to emissions reductions? What is the importance of natural emissions to the ozone formation process? Are there regional differences in the formation rates and efficiency for particulate matter as well?

4. What are the impacts of aerosols in California on radiative forcing and cloud formation? What are the most important precursors and formation processes for secondary organic aerosol? What is the role of aqueous phase processes in atmospheric transformations?

Transport and Meteorology

1. What are proper oceanic boundary conditions for coastal and regional atmospheric chemistry modeling? Are there variations in oceanic boundary conditions in northern and central California vs. the southern part of the state? What physical and chemical changes occur as a parcel of air moves from off-shore, through the shore zone, and inland?

2. How best can we characterize and model air flow over coastal waters and the complex terrain of California? For example: what is the best representation of air flow in the southern San Joaquin Valley, particularly with respect to flow between the San Joaquin Valley and South Coast Air Basin versus recirculation north along the Sierra Nevada and Coastal ranges?

3. What are the major deficiencies in the representation of chemistry and meteorology in research and operational models and how can models be improved through the collection of additional measurements? What physical and chemical processes are not captured well by available models? Is there an optimum grid resolution to capture all of the relevant physical and chemical processes that occur?

4. What are the important transport corridors for key chemical species and under what conditions is that transport important? 5. What is the relative roles of regional (North American) sources and long range transport (from East Asia) on aerosol forcing over California?

Farewell from John

ng — Fri, 23 Apr 2010 01:44:00 GMT

This is to announce that I’m moving to a new blog, effective immediately. The blog is called ClimateAbyss, and it will deal with a variety of weather and climate issues. Like Atmo.Sphere, the new blog is hosted by the Houston Chronicle. The look and feel will be much more like the regular Chronicle blogs, which brings several advantages.

First, the URL will be much simpler: http://blogs.chron.com/climateabyss . Links to specific blog entries will be less obscure too.

Second, the comments will be displayed on one continuous page, making it easier to read and participate in dialogues, and I will be able to approve comments more quickly.

Finally, I intend for ClimateAbyss to have a bit more variety in format. There will conference reports, news commentaries, interviews, and essays. High-quality guest blog entries are always welcome, as are suggestions for new topics. Areas of interest will vary from Houston to the entire globe. Right now, I’m reporting on a Texas air quality conference summarizing the latest in air pollution research.

Thank you for your readership and comments. Meanwhile, Barry Lefer is still here, and has some new ideas for Atmo.Sphere. Please give him your suggestions for things you'd like to see here. As for my blog and things you'd like me to do (preferably biologically possible things), I'll see you over at ClimateAbyss.

What Texas's Petition for Reconsideration to the EPA Says

ng — Tue, 16 Feb 2010 22:07:00 GMT

The State of Texas has filed a Petition for Review in US District Court and has accompanied this with a Petition for Reconsideration to the EPA. The Petition for Reconsideration lays out in detail the State's case that the EPA should reexamine its finding that anthropogenic greenhouse gases endanger the public health and welfare.

Announcement by Gov. Rick Perry, with Attorney General Abbott and Agriculture Commissioner Staples

I did not see the Petition until today, nor did I participate in its preparation. The purpose of this entry is to summarize the 38-page Petition so that readers can understand the complete basis of the State's argument and judge for themselves its validity.

Sections 1 and 2 are simply the introduction and overview sections.

In Section 3, the relevant law is quoted. A Reconsideration is called for if grounds for objection (of central relevance to the rule) arose after the period of public comment but before the end of the period for judicial review. The public comment period ended on June 23, 2009, and the deadline for judicial review is February 16, 2010 (today). The grounds for Texas's objection are primarily the Climategate emails and subsequent documentation of IPCC report errors, all of which came to light (the state argues) after June 23, 2009.

The February 16 deadline probably accounts for the hurried nature of the State's filing, with none of the CRU inquiries having yet been allowed to run their course. Thus the Petition relies extensively on the emails themselves and newspaper articles, and most of the quoted articles have appeared during the past month.

Section 4 presents examples of Texas enforcement of environmental regulations and encouragement of renewable energy sources.

Section 5 argues that the EPA director is required to make an indpendent, reasoned decision regarding greenhouse gases that is based on the best available science.

We're now up to page 7. Section 6 (taking eight pages) argues four main points. The first argument is that the emails show "overwhelming evidence of outcome-oriented conduct" on the part of CRU scientists and associates, "colluding and scheming to advance what they want the science to be -- even when the empirical data suggest a different outcome." The second argument is that these scientists were significant contributors to the IPCC's Fourth Assessment Report, as coauthors, lead contributors, and authors of papers relied upon throughout the IPCC reports. The third argument is that US Global Climate Research Program (USGCRP) and National Research Council (NRC) reports relied upon or incorporated findings from the IPCC reports. The fourth argument is that the EPA, by "relying on the major assessments of the USGCRP, IPCC, and NRC as the primary...bases of her endangerment decision" (quote from EPA), is actually relying on the IPCC and two other sources that relied upon the IPCC, such that a flaw in the IPCC undermines all three sources.

Section 7 (which takes up nearly half of the Petition) is a compendium of allegations pointing to the unreliability of the IPCC reports. I'll simply identify them here without commenting on their validity:
- CRU manipulated its data ("hide the decline", use of Russian weather stations, adjustments in New Zealand);
- CRU lost or destroyed much original data, making their analyses unreproduceable and unreliable;
- The IPCC was wrong about Himalayan glaciers;
- "Fabrication of results" regarding a study on the effect of urbanization on Chinese temperature records;
- The IPCC was wrong about how much of the Netherlands was under water;
- Various other conclusions, such as the vulnerability of Amazon rain forests, were based on questionable sources;
- The Climategate emails reveal attempts (sometimes successful) to manipulate the peer review process;
- The Chairman of the IPCC, Dr. Pachauri, has actual or apparent conflicts of interest;
- The Climategate emails reveal an intentional lack of transparency among contributors to the IPCC reports.

Section 8 describes how Texas might be harmed by future EPA greenhouse gas regulations: through restrictions on farming and ranching operations, harm to the oil and gas sector, and harm from those who derive royalties from oil and gas exploration, such as public education.

Section 9 describes others who are seeking to curtail the EPA's ability to regulate greenhouse gases, as well as quotations of other governments and scientists who have been critical of the IPCC recently.

Section 10 wraps things up, and I'll wrap things up by quoting it in full.

Since the CRU emails first appeared on the Internet in November, 2009, there has been a parade of controversies as new examples of improprieties and erroneous information are revealed to the public. Because the Administrator chose to rely on assessments by the IPCC, USGCRP, and the NRC—the latter two of which this petition has shown relied on the IPCC—as the primary scientific and technical basis for her Endangerment Finding, the Administrator’s decision is of central relevance to the Endangerment Finding within the meaning of Chapter 307 of the Clean Air Act. Thus, in light of the serious misconduct the State has demonstrated—data manipulation, loss or destruction of information, reliance on questionable source materials, abuse of the peer review process, suppression of dissent, conflicts of interest, and failure to comply with freedom of information laws—the EPA should grant this petition and reconsider the Endangerment Finding. Granting this petition would be consistent with actions taken by governments worldwide to assess problems afflicting the IPCC and it would further allow the agency to conduct its own scientific assessment, independently consider the available scientific information, and then, in the Administrator’s own judgment, make a determination that is supported by the law and facts.

Record snowstorms are caused by ... the weather

ng — Wed, 10 Feb 2010 20:52:00 GMT

I was reading a post over at Joe Romm's blog in which he noted that a remarkable number of Republicans are trying to link the recent East Coast snowstorms to climate change skepticism. To be fair, most the linkages did seem to be of the nature of "warmer temperatures would have been useful for making a lot of this stuff rain rather than snow" rather than "snow proves the Earth is not warming".

This is consistent with the "Montanans for Global Warming" image posted on the side of my desk, courtesy of Duckboy, showing a dozen or so cold-looking individuals knee-deep in snow outside a tavern. So I appreciate the sentiment, although that sentiment is unlikely to be similarly expressed this July.

Romm goes on to refer to an MSNBC commentator and to Jeff Masters for the proposition that heavier snowstorms are exactly what would be expected from global warming. The commentator describes a fascinating scenario in which the atmosphere gets loaded up with extra moisture during the hot summers, and then when winter comes along and cools the air, all that extra moisture goes "whoom" and falls to the ground as snow. (I'm exaggerating a bit, but not much.) One of the many flaws in that scenario is that your typical water molecule only manages to stay in the atmosphere for a week or so.

Jeff Masters knows a whole lot more about meteorology. In his post discussing the relationship between the snowstorms and global warming, he concludes:

"Of course, both climate change contrarians and climate change scientists agree that no single weather event can be blamed on climate change. However, one can "load the dice" in favor of events that used to be rare--or unheard of--if the climate is changing to a new state. It is quite possible that the dice have been loaded in favor of more intense Nor'easters for the U.S. Mid-Atlantic and Northeast, thanks to the higher levels of moisture present in the air due to warmer global temperatures."

Some good stuff there -- "loading the dice" is a great way to describe how weather events relate to climate. Climate is effectively the accumulation of weather events, and climate change means that certain weather events become more frequent while others become less frequent. But let's look at why Masters thinks more intense Nor'easters is a possibility.

He notes two requirements for a record snowstorm: near-record amounts of moisture in the air (or a very slow-moving storm) and temperatures cold enough for snow. I'd add a third: strong upward motion, which is needed to convert the moisture into snow as rapidly as possible. The issue becomes: how is global warming expected to affect the frequency by which these requirements will occur over the northeastern United States?

Masters says that it's easy to get temperatures cold enough for snow, which is correct. Even in a much warmer world, it will still be cold in the winter in the Northeast. As for moisture, Masters says:

"Global warming theory predicts that global precipitation will increase, and that heavy precipitation events--the ones most likely to cause flash flooding--will also increase. This occurs because as the climate warms, evaporation of moisture from the oceans increases, resulting in more water vapor in the air. According to the 2007 Intergovernmental Panel on Climate Change (IPCC) report, water vapor in the global atmosphere has increased by about 5% over the 20th century, and 4% since 1970. This extra moisture in the air will tend to produce heavier snowstorms, assuming it is cold enough to snow."

This is generally correct, except for the conclusion drawn in the last sentence. The rate of evaporation from the ocean depends on the difference between the actual amount of water vapor in the air and the potential amount of water vapor. The potential amount increases very rapidly with temperature, so the rate of evaporation (and the global mean amount of water vapor in the atmosphere) should increase, and according to the observations, it has indeed increased.

It then makes sense that there should be (and is) more precipitation too, since quite literally what goes up must come down, and (remember from above) water vapor doesn't hang around in the air very long.

For what follows, though, you need to know a little basic information about how precipitation forms. First, you need upward motion, either on a thunderstorm scale or on a broader storm system scale. The upward motion cools the air, eventually cooling it to its dewpoint temperature, at which point the air is "saturated" with water vapor and any further cooling will cause some of the water vapor to convert from gas form into liquid or solid form. Since the air is saturated, the rate at which precipitation is generated depends directly on the air temperature (warmer means more water vapor to condense) and the upward velocity of the air.

Thus, global warming ought to increase the heaviest precipitation everywhere (since it will occur under warmer temperatures, there will be more precipitation generated) and ought to increase the amount of snow in cold locations (since the snow will be forming at warmer temperatures, there will be more snow generated). Masters also notes that storm tracks are (and are expected to be) shifting northward, so the frequency of storms at high latitudes should increase.

But what about Washington, D.C.? There, during winter, DC is on the edge: sometimes rain because it's warm, sometimes snow because it's cold. As you might imagine from what I've described above, the heaviest snowfalls tend to occur when temperatures are just slightly below freezing in the column of air above DC, because that maximizes the amount of water vapor available to form snow without having temperatures so warm that rain is produced instead. (This effect is only partially offset by the tendency for snow to be less dense at colder temperatures, thus requiring less total water to make a foot of snow.)

Herein lies the problem with Masters' argument: global warming or no global warming, the heaviest snow occurs in DC when the air column is saturated and just below freezing, and a saturated slightly-subfreezing air column will always have exactly the same amount of water vapor, irrespective of what happens to the global average amount of water vapor. It will thus produce almost exactly the same amount of snow.

How can that be? you might say. If there's more water vapor in the air globally, a given storm should produce more snow, shouldn't it? Not quite. It should produce more precipitation. And therein lies the rub. Take a given storm, optimally configured for heavy snow for DC in the year 1900, and let global warming raise its temperatures and water vapor. Now that same storm would produce more precipitation, but it would fall mostly as rain in DC. Start with a colder storm (with correspondingly less snowfall) from 1900 and apply global warming, and you do indeed get more snow, but not more snow than our first optimal storm from 1900 would have produced.

Bottom line: more global moisture won't, by itself, change the extreme snowfall events near the rain-snow line.

There are a few other factors to consider, though:

You could increase your chances of heavy snow by increasing the frequency of storm events, but that's apparently happening at high latitudes rather than middle latitudes. If El Nino events become more common under global warming, one would expect more East Coast winter storms, but the jury's still out on whether El Nino events will become more or less common.

You could increase your chances of heavy snow by increasing the strength of the upward motion. That may happen in general because of warming temperatures and more water vapor, but I don't see that happening at a given temperature, which is what we'd need for more intense East Coast snowstorms.

Finally, you could increase your chances of heavy snow by increasing the geographical size of the area that has optimal air column temperatures. Steve Scolnik notes that the current storm has an unusually large area at just-cold-enough-to-snow, whereas previous major storms had very cold air relatively close by. And global warming is (and should be) decreasing the pole-to-equator temperature gradient. But at a given temperature, a weaker temperature gradient should imply weaker upward motion.

In conclusion, any link between global warming and the recent East Coast snowstorms is either flawed or is sheer speculation. Such a link might indeed exist, but for now, for all we know, they are simply historic snowstorms.