Ozone pollution improving in the U.S.

By: Dr. Jeff Masters , 7:03 PM GMT on May 01, 2007

Share this Blog
2
+

Air pollution season is here, and the good news is that ozone pollution in 2006 was considerably better than in previous years. Along with pollution due to small particles (particulate matter), ground-level ozone is the most serious pollutant in the U.S. Ozone levels in 2006 showed improvement in 23 out of 35 of the major cities in the U.S. (Figure 1) compared to 2005, and was at or below the 10-year average in all but five cities. Atlanta, Georgia, showed the greatest jump in the number of unhealthy days, from 17 in 2005 to 30 days in 2006; however, this number was still below the 10-year average. Many western cities reached levels at or above the 10-year average, including San Diego, Sacramento, Denver, and Las Vegas. This was in part due to much above average summertime temperatures in the western U.S. (Figure 2). Los Angeles had the worst ozone pollution in the U.S., with 46 unhealthy days. Los Angeles also was the most polluted city overall in 2006, according to the American Lung Association. However, Los Angeles' bad ozone days declined by 16% in 2006 compared to 2005.


Figure 1. The number of days in May through September of 2005 and 2006 in which ground-level ozone reached Unhealthy for Sensitive Groups--an Air Quality Index (AQI) above 100. Corresponding 10-year averages are also shown. Image credit: EPA.

Ozone pollution has improved
Is the improvement seen in ozone levels in 2006 merely due to a lack of meteorological conditions that favor air pollution? To check, I've plotted the difference in surface temperature (degrees C) from May-September 2006, compared to the 10-year average from 1995-2005 (Figure 2). The chemical reactions that form ozone are most efficient at high temperatures, so if the summer of 2006 was cooler than usual, we'd expect a drop in ozone levels. However, the summer of 2006 was the second warmest in U.S. history--but ozone levels still dropped. All of the cities where ozone increased significantly in 2006 over 2005 levels were areas where temperatures were above average. Los Angeles had summer temperatures more than 1 degree C above normal, yet still recorded a drop in ozone, suggesting that strategies to control ozone pollution there are paying dividends. In fact, new rules to limit nitrogen oxide emissions from power plants have been enacted nation-wide in the past few years, and the ozone pollution statistics from 2006 are evidence that these emissions rules are working. Ozone pollution since 1980 has dropped 21% (Figure 3), despite the fact that the average summer temperatures have generally been increasing.


Figure 2. The difference in surface temperature (degrees C) from May-September 2006, compared to the 10-year average from 1995-2005. Temperatures were above the 10-year average across most of the country, except for New Mexico, and portions of the Ohio Valley surrounding Kentucky. Image credit: NCAR/NCEP.


Figure 3. Trends in ozone air pollution in the U.S. (white line) and uncertainty (blue areas, marking the standard deviation). The federal standard of 0.08 ppm is indicated by the dashed line. Since 1980, maximum ozone levels have declined 21%. Since 1990, the decline has been 9%. Note that the lowest ozone levels were recorded in 2004, which was an exceptionally cool summer across most of the U.S. Image credit: U.S. EPA.

Next blog (Thursday): Pollution costs and deaths exceed the impact of a new Hurricane Katrina hitting the U.S. each year.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 338 - 288

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13Blog Index

338. StoryOfTheCane
8:55 PM GMT on May 02, 2007
if youve ever been golfing in Central Florida there is absolutely nothing like it, 365 days a year, wet season you lose a little more balls than youd like though, puddles kind of show up in random places and dont go away until the dry season
337. StoryOfTheCane
8:51 PM GMT on May 02, 2007
small world franck, I just moved from Winter Park, FL about 2 months ago, played golf all the time at Lake Orlando, had a lime tree in my back yard
336. StoryOfTheCane
8:49 PM GMT on May 02, 2007
those donuts look delicious
335. airman45
8:31 PM GMT on May 02, 2007
Good night all!
Member Since: April 2, 2007 Posts: 0 Comments: 3506
334. franck
8:28 PM GMT on May 02, 2007
Are those Krispy Kremes?
Member Since: August 30, 2005 Posts: 0 Comments: 1150
333. franck
8:27 PM GMT on May 02, 2007
Oh, don't worry about unrelated photos. Everybody does it.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
332. franck
8:25 PM GMT on May 02, 2007
Yeah, I lived in Winter Park near Orlando for a while and people there grew tropical fruits in their yards, though the city was pretty much one giant strip mall.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
331. airman45
8:26 PM GMT on May 02, 2007
Thanks for the doughnuts!!!
Member Since: April 2, 2007 Posts: 0 Comments: 3506
330. airman45
8:23 PM GMT on May 02, 2007
Sorry. Just picking on you!! No more peeps, at least not today!
Member Since: April 2, 2007 Posts: 0 Comments: 3506
329. kmanislander
8:23 PM GMT on May 02, 2007


Moisture levels on the rise in the Caribbean after months of little or none,particularly in the S and NW sectors
Member Since: August 19, 2006 Posts: 0 Comments: 15725
328. NRAamy
8:23 PM GMT on May 02, 2007
donut

airman, please take a donut...that should keep you quiet...

;)

Ok, I promise NO MORE photos unrelated to weather!!!!!
Member Since: January 24, 2007 Posts: 317 Comments: 31946
327. NRAamy
8:21 PM GMT on May 02, 2007
airman, you get on my last nerve...

;)
Member Since: January 24, 2007 Posts: 317 Comments: 31946
326. airman45
8:19 PM GMT on May 02, 2007
Im a Florida boy originally, from Pensacola. But I have lived in Europe for the past 20 years (Germany, Italy, England, and now Portugal).
Member Since: April 2, 2007 Posts: 0 Comments: 3506
325. thisisfurious
8:12 PM GMT on May 02, 2007
Airman, do you hail from Portugal longtime? Or were you reared somewhere out here?
324. airman45
8:02 PM GMT on May 02, 2007
Could someone please explain to me why Los Angles has the worst air pollution in the nation?
And airman, I don't wanna hear another peep outa you about Portugal...I know, I know...


Peep, peep.........O.K., I wont say anything about our nice fresh air.

And, as an FYI, the last orange grove in Orange County ( suburb of LA ) was mowed under and made into a shopping mall when I was 16..."paved paradise, and put up a parking lot"...

However we do still grow oranges here. I have a lemon tree in my backyard and just picked 60 huge lemons from it. Enough lemonaid for about 3 months...peep, peep....
Member Since: April 2, 2007 Posts: 0 Comments: 3506
323. thelmores
8:00 PM GMT on May 02, 2007
Hard to believe CNN would air anything contradicting GW!

Maybe they got tired of FNC eating their lunch! LOL
Member Since: September 8, 2005 Posts: 0 Comments: 3805
322. hurricane23
8:00 PM GMT on May 02, 2007
Leftovers yea june1 is coming fast but keep in mind that does not mean we are going to see a hurricane moving threw the gulf of mexico the first week of june.Typically june and july are quite months and this year will probably be no different.Early august threw october is the meat of the season.Lets hope for a year similar to 2006.

Adrian's Weather
Member Since: May 14, 2006 Posts: 8 Comments: 13626
320. hurricane23
7:50 PM GMT on May 02, 2007
Dont think so cloud-cover will limit thunderstorm activity if it trys to get going.
Member Since: May 14, 2006 Posts: 8 Comments: 13626
319. BoyntonBeach
7:49 PM GMT on May 02, 2007
Looks like some T-storms are starting to pop down there h23...maybe you'll get lucky today.
Member Since: July 5, 2006 Posts: 0 Comments: 1
318. NRAamy
7:48 PM GMT on May 02, 2007
franck,

Yeah...it's so sad...they need to rename the county...

how about Smog County?



Member Since: January 24, 2007 Posts: 317 Comments: 31946
317. hurricane23
7:45 PM GMT on May 02, 2007
Good afternoon,

Just added bouy observations to my recon page along with marine observations make sure you check it out.

Recon and Bouy Observation page
Member Since: May 14, 2006 Posts: 8 Comments: 13626
316. franck
7:30 PM GMT on May 02, 2007
..for treason against the people.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
315. franck
7:30 PM GMT on May 02, 2007
If I ruled Glenn Beck would be executed, and anyone mentioning his name would be imprisoned.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
314. franck
7:28 PM GMT on May 02, 2007
NRAamy...my condolences about the oranges.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
313. weatherboykris
7:21 PM GMT on May 02, 2007
Posted By: PIRSRON at 7:04 PM GMT on May 02, 2007.

Everyone be sure to watch Glenn Beck tonite @ 9 est. It is going to be make all these global warming geeks crap in there pants.


He's on at 7 too.I'll try to catch one of the airings.
Member Since: December 9, 2006 Posts: 125 Comments: 11346
312. Patrap
7:15 PM GMT on May 02, 2007
w Link.. Al Gore on NOAA radios. Public Service Announcement
Member Since: July 3, 2005 Posts: 420 Comments: 127536
310. thelmores
6:52 PM GMT on May 02, 2007
Maybe they should call it "non-orange county"! LOL

I'll take orange groves over pavement anytime! ;)
Member Since: September 8, 2005 Posts: 0 Comments: 3805
309. NRAamy
6:39 PM GMT on May 02, 2007
Thank you everyone!! I understand the situation much clearer now.

:)

And, as an FYI, the last orange grove in Orange County ( suburb of LA ) was mowed under and made into a shopping mall when I was 16..."paved paradise, and put up a parking lot"...
Member Since: January 24, 2007 Posts: 317 Comments: 31946
308. stoormfury
6:33 PM GMT on May 02, 2007
could anyone tell me what is wrong with the site national hurricane image index
Member Since: August 22, 2006 Posts: 0 Comments: 2600
307. franck
6:13 PM GMT on May 02, 2007
NRAamy...yes, for sure LA has the far greater problem with pollution due to geographical conditons. Los Angeles was an excellent area for a sizable number of inhabitants, as long as there was little industrial production. Growing oranges and making movies doesn't pollute much. But it is not an area conducive to any kind of heavy industry.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
306. crackerlogic
6:12 PM GMT on May 02, 2007
did every one get enough of "the first wave"
305. catastropheadjuster
6:07 PM GMT on May 02, 2007
This isn't about the topic you'll are talking about but if anyone and everyone would stop by my blog and just read it I would greatly appreciate it. It is important. And I might just work I was ask to pass it on to as many people i could so i thought I would pass it on to all the WUBA Family here. It will just take a minute to read so please stop by, I wouldn't bother you'll with these but it does make since.
Thanks to everyone in advanced.
Have a great day.
Sheri
Come on you'll this will only take a second of your time.
Member Since: August 24, 2006 Posts: 21 Comments: 3652
304. animalrsq
6:06 PM GMT on May 02, 2007
LA is a much deeper "bowl" with mountains to the east. Holds the pollution in.
Member Since: August 4, 2006 Posts: 0 Comments: 214
303. crackerlogic
6:05 PM GMT on May 02, 2007
LA beiing in a vally the air gets stale and doesn't move areound the much in the summer, place like N.O. seem to gettes winds coming off the gulf that move the air around, plus N.O. is only in a 30 ft bowl compared to a bowl a couple of thousand feet
302. franck
6:02 PM GMT on May 02, 2007
NRAamy..well, yes New Orleans is very polluted, and probably per capita more polluted than Los Angeles. But Los Angeles historically has had about 10 times the population of New Orleans. Now Los Angeles has 20 times the population of New Orleans, since half the population of New Orleans recently migrated elsewhere, though they still are able to vote in local elections.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
301. NRAamy
5:52 PM GMT on May 02, 2007
"particulant bowl"...too bad we can't flush it...

Ok, I really don't know what I am talking about here, so be kind...but isn't New Orleans a sort of bowl? And if so, why are their scales on the top graph so low?
Member Since: January 24, 2007 Posts: 317 Comments: 31946
300. franck
5:47 PM GMT on May 02, 2007
NRAamy...the LA 'basin'. The area is a particulate bowl, and at certain times the pollution can not vacate.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
299. NRAamy
5:40 PM GMT on May 02, 2007
In looking at the top graph, the 2006 Ozone Season Review, could someone please explain to me why Los Angles has the worst air pollution in the nation? NYC and Houston are both very large, congested cities. Why is LA the worst?

And airman, I don't wanna hear another peep outa you about Portugal...I know, I know...

;)

Thanks,
Amy
Member Since: January 24, 2007 Posts: 317 Comments: 31946
298. hurricane23
1:03 PM EDT on May 02, 2007
LOL now the GFS has a system developing in the eastern pacific at about 348-384 which is extremely long range and to be ignored.


Adrian's Weather
Member Since: May 14, 2006 Posts: 8 Comments: 13626
297. Tazmanian
9:37 AM PDT on May 02, 2007
crownwx nic site
Member Since: Posts: Comments:
296. thelmores
4:34 PM GMT on May 02, 2007
man, now we have "tropical tornado's"? LOL
Member Since: September 8, 2005 Posts: 0 Comments: 3805
295. franck
4:35 PM GMT on May 02, 2007
That's amazing footage PR. Thanks.
Member Since: August 30, 2005 Posts: 0 Comments: 1150
294. Crisis57
4:35 PM GMT on May 02, 2007
CROWNWX nice Hurricane Season outlook you have there and some very interesting points you mentioned. My biggest concern and one you mentioned is the High and where its located. I know i speak for many here in south florida when i say i'm exhausted of these storms coming here and truly don't want to see anymore
Member Since: Posts: Comments:
293. weatherboykris
4:30 PM GMT on May 02, 2007
Ok,thanks.
Member Since: December 9, 2006 Posts: 125 Comments: 11346
292. crownwx
4:26 PM GMT on May 02, 2007
Weatherboykris:
Yes, I am the one that updates the Crown Weather blog, as well as the actual Crown Weather Services site. This hurricane season, I will be posting all of my tropical weather thoughts, etc on the Tropical Weather Discussion page rather than the blog site, because I have run into problems trying to post blogs in a timely manner.
Member Since: Posts: Comments:
291. Patrap
11:25 AM CDT on May 02, 2007
Large well formed and long lived waterspout in Croatian Lake..
Member Since: July 3, 2005 Posts: 420 Comments: 127536
290. StormJunkie
4:24 PM GMT on May 02, 2007
It has to be chess, there is no invest. GFDL will not run unless there is an invest.

I still think it is a test run though.
Member Since: Posts: Comments:
289. StormJunkie
4:24 PM GMT on May 02, 2007
I have it at home '03. Just not sure how big company feels about me installing it at work...
Member Since: Posts: Comments:
288. weatherboykris
4:23 PM GMT on May 02, 2007
Hi crownwx.You are the guy who updates that site's blog?If so,great job!I read that every day during the season.
Member Since: December 9, 2006 Posts: 125 Comments: 11346

Viewing: 338 - 288

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
72 °F
Overcast