Ozone pollution improving in the U.S.

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

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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

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238. MissBennet
8:48 AM CDT on May 02, 2007
Thanks weatherguy, but I still would like to know what an ideal set up is for the US?

Or is it different for all the different regions. Such as, the east coast would really love to see a more eastern set up, so hurricanes would curve out to sea on the western edge before hitting land; and FL would love to see a more Northern sitting high so hurricanes go more north toward GA and the Carolina's than to them?

Living in New Orleans and from reading that article I know that I don't want to see another high in the west of the Atlantic sitting a little low over FL and North Carribbean.
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237. crackerlogic
1:48 PM GMT on May 02, 2007
hey my surfing report is showing waves off of florida on east and west coast on mon and tue of next week. i don't see any weather coming. any ideas?

http://www.wetsand.com/swellwatch/swellwatch.asp?locationid=2&tabid=1441&subtabid=0&CatId=277
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236. TheCaneWhisperer
9:45 AM EDT on May 02, 2007
Sorry about the links! It was an interactive map, they seemed to work for a few minutes. They must have timed out or something.
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235. Patrap
8:46 AM CDT on May 02, 2007
FLIGHT TWO
A. TRACK A61/ MANTA/ 15/1300Z
B. AFXXX 06WSA TRACK61
C. 15/0730Z
D. 4 DROPS AS PUBLISHED PLUS MANTA EQUAL 5
E. 27,000 TO 35,000 FT/ 15/1500Z
F. FLOWN COUNTERCLOCKWISE

2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.
JWP
Member Since: July 3, 2005 Posts: 426 Comments: 128651
234. TheCaneWhisperer
9:42 AM EDT on May 02, 2007
I should have indicated the specifics of that article are in reference to the 2006 season! But, the general information on the high applies to all years.
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233. hurricane23
9:42 AM EDT on May 02, 2007
Yea 03 its been stuck showing this feature for many runs now but then again this is expected this time of year and will only get worse as the season moves along.Have of it is just garbage from the GFS but as is stated when more models jump on this then i'll take it a little more seriously.
Member Since: May 14, 2006 Posts: 8 Comments: 13804
232. hurricane23
9:41 AM EDT on May 02, 2007
You can either use imagesgack which i use alot or you can use postimage.org which is great.
Member Since: May 14, 2006 Posts: 8 Comments: 13804
231. weatherguy03
9:40 AM EDT on May 02, 2007
Ya know what 23, I am actually starting to gain alittle interest in what the GFS has been showing. Just alittle!..LOL Its been there for awhile, still a long way off, but something to keep one eye on.
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230. weatherguy03
9:38 AM EDT on May 02, 2007
Because of La Nina, that would focus the Bermuda High more towards the West and the South. Someone can correct me if I am wrong. Hurricanes can travel along the East side of High Pressure, but they would move towards the South or Southeast. You will see this happen a few times a year.
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229. weathermanwannabe
9:36 AM EDT on May 02, 2007
Good Morning All...Drought for Florida appears to be a certainty as they have just announced possible year round water restrictions for South Florida and a big problem with wild fires...Much like last year, Florida will actually need some good tropical storms (hopefully not major hurricanes) in order to make up the rain fall deficit once we get into July and August....
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228. kmanislander
1:35 PM GMT on May 02, 2007
Hi Hurricane

How do I resize my post to restore the margins ?
Member Since: August 19, 2006 Posts: 0 Comments: 15842
227. hurricane23
9:33 AM EDT on May 02, 2007
Good morning...

Links dont work canewhisper,but overall looking at the lastest GFS run and it continues developing a LOW in the caribbean moving NE away from the U.S.Persoanlly i would like to see more model agreement before i buy into this.

Here's a view of the 6Z...

FFF
Member Since: May 14, 2006 Posts: 8 Comments: 13804
226. kmanislander
1:29 PM GMT on May 02, 2007
whoa didn't mean to blow the margins.
Anyway to fix this ??
Member Since: August 19, 2006 Posts: 0 Comments: 15842
225. MissBennet
1:28 PM GMT on May 02, 2007
CRAP! Just typed up this really nice detailed question, and accidently pushed the back button and erased all of it!!

Here is the short short version (ala Mel Brook's SpaceBalls "do you? Do you? good you're married, now kiss her!"):

I read the article that CWhisperer posted and then read StormJ's analysis of the lastest forcast on the B-high and I seem to be getting mixed messges as to what is the more preferred set up for the B-High. West or East?

Would someone please clarify for me?

Second Question: do Hurricane ( more than likely Cape Verde 'canes) ever travel the eastern edge of the B-high? or is that pretty rare?

Thank you!
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224. kmanislander
1:27 PM GMT on May 02, 2007
ut
Member Since: August 19, 2006 Posts: 0 Comments: 15842
223. Fl30258713
1:23 PM GMT on May 02, 2007
TheCaneWhisperer
I couldn't get those links to work.
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222. TheCaneWhisperer
9:14 AM EDT on May 02, 2007
Sorry about that! It is an ineractive map, links won't work. But anyway, La Nina's do favor a more eastward displaced Bermuda High!
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221. pottery
8:55 AM AST on May 02, 2007
Yes indeed, Rascal. That is looking like lots of rainfall in that system. Is it a Trop. Wave ? or ITZC activity. Its far south, and we will see if it can hold its own over the ocean. My feeling is it will not, but I wish it would !
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220. chessrascal
12:51 PM GMT on May 02, 2007
i think the wave has gained some convection since last night any other thoughts?
219. StormJunkie
12:46 PM GMT on May 02, 2007
I would think that would be the E portion of the Bermuda high, but was not sure TCW. That high does not really seem to come from the Bermuda high when looking at the models. But I do agree it looks like a split Bermuda high.

None the less that is not good for our rain situation...

Will read the article in a minute. Thanks!
Member Since: August 17, 2005 Posts: 26 Comments: 16866
218. chessrascal
12:48 PM GMT on May 02, 2007
lol

heres the latest visible of the wave.
217. pottery
8:37 AM AST on May 02, 2007
Trinidad Weather :
84 f, 88 with heat index
Forecast to go to 88 +
Its only 8:45 am
A few clouds, moving fast westward.

Hoping for rain here too !
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216. TheCaneWhisperer
8:40 AM EDT on May 02, 2007
THIS is the article I meant to Post!
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215. TheCaneWhisperer
8:38 AM EDT on May 02, 2007
That would be great if it did set up further east though!
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214. chessrascal
12:35 PM GMT on May 02, 2007
the wave is getting its act together.

213. TheCaneWhisperer
8:26 AM EDT on May 02, 2007
Here is a good article on the Bermuda High SJ! Most of what I have read says that the Bermuda High will not settle into place until July! The high pressure on the east coast is a La Nina-ish pattern! Woulden't that high pressure be the western flank of the Bermuda High?

The long range forcast for our area is behaving more and more like a La Nina weather pattern everyday! Not good either because La Nina means drought for Florida!
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212. chessrascal
12:30 PM GMT on May 02, 2007
im in SWFL and it is
80.2 degrees
71% humidity
wind is calm
and there is not one cloud.
211. TheCaneWhisperer
8:22 AM EDT on May 02, 2007
Morning All! Going to be a hot one in SEFL today!

Ripe @ 8:30 already!
81.9 F / 27.7 C
Partly Cloudy
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210. StormJunkie
12:12 PM GMT on May 02, 2007
Interesting to note the forecast for the Bermuda high. It looks like it si going to receed to the W a good bit over the next week or so. Also looks like there will be a large area of high pressure over the SE coast for sometime to come. This is not good for those who need rain, but the high pushing to the E would be a good thing if that pattern holds in to the tropical season as it would allow storms to recurve. Not sure we can count on that as it is still to early to really get a good idea of how the high will act during the season, but this could be an encouraging sign...

Member Since: August 17, 2005 Posts: 26 Comments: 16866
209. StormJunkie
12:02 PM GMT on May 02, 2007
That sounds about right HM, and I wondered the same thing after this discussion. I think the fact they are so far south and it is so early the NHC would not recognize it as an actual tropical wave because of the very low chance that it will survive for very long.
Member Since: August 17, 2005 Posts: 26 Comments: 16866
208. HurricaneMyles
11:48 AM GMT on May 02, 2007
I wonder what the difference is between what we are seeing coming off the coast of Africa now and what we will see in a few months. What we have now appears to be inverted surface troughs, the same as tropical waves - the only difference I can see is that waves now are 5-10 degrees farther south then they will be in August.
Member Since: January 12, 2006 Posts: 5 Comments: 827
207. StormJunkie
9:26 AM GMT on May 02, 2007
Morning y'all. I see things got intereting last night.

kris, I would have to agree with TCW on this one. If it was a true wave the NHC would have issued a special statment not to mention I don't think they would have called it "wave like" if it was a wave.

Anywho, enough of that. There will be plenty of waves and blobs to keep everyone busy soon enough.

Off to work. Y'all have a great day!
SJ
Member Since: August 17, 2005 Posts: 26 Comments: 16866
206. airman45
9:20 AM GMT on May 02, 2007
Good morning! How is everyone? We had a rainy night in Portugal. The dry season should start any day now. Then won't see rain for about four months! Enjoy your blogging about blobs.
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205. TayTay
8:37 AM GMT on May 02, 2007
"if ur all stress now 28 days out i cant wait till i see u here in june remember T-MINUS 720 hrs and counting till hurricane season"

I've been reading this blog and the comments since Jeff first started it a few years ago. Trust me, it has always been a place to go crazy for 'waves'. I don't like to get involved too much since everyone goes crazy for blobs. No matter what time of the year, someone will go crazy over blips on the satellite.
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203. TheCaneWhisperer
4:25 AM GMT on May 02, 2007
Tropical Wave Like Characteristics do not mean Tropical Wave!
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202. TheCaneWhisperer
4:20 AM GMT on May 02, 2007
It is currently analized as a surface trough kris! If it is offically analized as a tropical wave the NHC will break out a special section under the header TROPICAL WAVES! Until that is done, it is nothing but a trough to me!
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201. Levi32
8:12 PM AKDT on May 01, 2007
LOL.......I see I built quite a reputation after my debate this morning.
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200. Tazmanian
9:02 PM PDT on May 01, 2007
Posted By: weatherboykris at 8:35 PM PDT on May 01, 2007.

You called me Levi.


LOL

No offense weatherboykris
Member Since: May 21, 2006 Posts: 5091 Comments: 115239
199. weatherboykris
4:01 AM GMT on May 02, 2007
I'm not stressed.It's no big deal.
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198. KEEPEROFTHEGATE (Mod)
3:53 AM GMT on May 02, 2007
if ur all stress now 28 days out i cant wait till i see u here in june remember T-MINUS 720 hrs and counting till hurricane season
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197. weatherboykris
3:49 AM GMT on May 02, 2007
The wave was verified when they put it on the map!
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196. TheCaneWhisperer
3:44 AM GMT on May 02, 2007
Sorry Kris, seems to be alot of kings going on here, I confused you with the rest.

Just tell me where the wave is verified here?

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N12W 4N20W 3N30W CROSSING THE
EQUATOR AT 40W INTO NE BRAZIL NEAR 2N47W. THE LARGEST
CONCENTRATION OF CONVECTION NEAR THE ITCZ IS ASSOCIATED WITH A
TROUGH THAT IS ALONG 23/24W ON THE 18Z SURFACE MAP. DURING THE
LAST FEW HOURS...THE STRONG CONVECTION ASSOCIATED WITH THIS
TROUGH HAS DIMINISHED A BIT. THIS AREA OF CONVECTION CAME OFF
THE AFRICAN COAST TWO DAYS AGO AND HAS BEEN MOVING WWD SHOWING
SOME TROPICAL WAVE-LIKE CHARACTERISTICS. AS THE DAY WORE ON...A
DRIFTING BUOY LOCATED NEAR 23W SHOWED A WIND SHIFT FROM NE TO SE
WITH THE TROUGH PASSAGE. SCATTERED MODERATE CONVECTION IS FOUND
AHEAD OF THE TROUGH AXIS FROM EQ-5N BETWEEN 25W-32W. ANOTHER
CLUSTER OF STRONG CONVECTION IS INLAND OVER AFRICA APPROACHING
THE PRIME MERIDIAN.


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195. weatherboykris
3:35 AM GMT on May 02, 2007
And...a wave is a wave.They marked a wave on the map,they said there was a wind shift on the buoys and Quikscat.It's a wave.Not worth arguing over,as it won't develop anyway.
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194. weatherboykris
3:34 AM GMT on May 02, 2007
You called me Levi.
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193. TheCaneWhisperer
3:26 AM GMT on May 02, 2007
A- I know how to read a map, there are several vertical lines as you call them on the map, otherwise noted as surface troughs. When there is an official Wave the NHC will post a special section concerning tropical waves. This area in question is behaving like a wave but, is not classified as such at the current time.
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192. weatherboykris
3:31 AM GMT on May 02, 2007
vortices
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191. thelmores
3:15 AM GMT on May 02, 2007
if you study the loop of mid atl to Africa, you can see that that 2nd wave is already being sheared a little..... and UL winds to the WNW are zooming ENE....

high shear/relatively low SST's = no invest!

But after last year, even a blob is exciting! LOL

2006..... the year of weak multiple vortice storms! (sp?)

multiple Vorti? LOL
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190. weatherboykris
3:24 AM GMT on May 02, 2007
No offense.
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189. Rodek
3:22 AM GMT on May 02, 2007
Thanks Kris!!! 91 ft... wow!!!
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188. weatherboykris
3:22 AM GMT on May 02, 2007
Learn to read a surface map,canewhisperer.The vertical line is the waveLink
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.