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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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
287. weatherguy03
12:17 PM EDT on May 02, 2007
SJ. Get Firefox. Now!!..LOL
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286. weatherguy03
12:17 PM EDT on May 02, 2007
Happens when ya get older Kris!! You will be there oneday!..LOL
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285. crownwx
4:14 PM GMT on May 02, 2007
I posted my thoughts and predictions for the 2007 Hurricane Season on our Tropical Weather Discussion page at http://www.crownweather.com/tropdisc.html. Like many others, I think we will have a fairly busy season and the position of the high pressure system in the Atlantic does concern me quite a bit.
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284. weatherboykris
4:14 PM GMT on May 02, 2007
Do you know Cantore used to have hair?LOL,they were showing some bloopers(I geuss from the 80s or early 90s,given the state of their graphics).
Member Since: December 9, 2006 Posts: 125 Comments: 11346
283. HurricaneMyles
4:10 PM GMT on May 02, 2007
.
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282. Tazmanian
9:15 AM PDT on May 02, 2007
weatherboykris hello
Member Since: May 21, 2006 Posts: 5091 Comments: 115239
281. weatherboykris
4:14 PM GMT on May 02, 2007
hello
Member Since: December 9, 2006 Posts: 125 Comments: 11346
280. Tazmanian
9:12 AM PDT on May 02, 2007
The Weather Channel Celebrates 25 Years today
Member Since: May 21, 2006 Posts: 5091 Comments: 115239
279. chessrascal
4:10 PM GMT on May 02, 2007
thanks SJ but its to bad that it isnt
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278. TheCaneWhisperer
12:08 PM EDT on May 02, 2007
That is a Test Run Chess! They do those every year about this time!
277. StormJunkie
4:07 PM GMT on May 02, 2007
Chess, the GFDL is storm specific. Therfore that is either a old storm or a test run. The GFDL will not initialize until a system is labeled a invest.

Back to work all.
Member Since: August 17, 2005 Posts: 26 Comments: 16866
276. chessrascal
4:06 PM GMT on May 02, 2007
.
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275. chessrascal
3:57 PM GMT on May 02, 2007
.
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274. TheCaneWhisperer
11:53 AM EDT on May 02, 2007
I have been researching La Nina Effects, Bermuda High and several other factors for about 6 months now. My findings, besides all the conflicting information out there, further concrete just how unpredictable everything is and how each year seems to have it's own MO.
272. hurricane23
12:00 PM EDT on May 02, 2007
Posted By: StormJunkie at 11:50 AM EDT on May 02, 2007.

23, please edit your 2:49 post so it does not stretch the blog. I know this is only a issue for IE users and not FireFox, but it is a little frustrating as some of us at work do not have the option of using FireFox.

Thanks☺


Thats my bad but i was showing levi32 some of my software.

Large image resized.
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271. Patrap
10:58 AM CDT on May 02, 2007
Subject: Special Weather Statement



WWUS84 KLIX 021541
SPSLIX

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1041 AM CDT WED MAY 2 2007

LAZ040-059>070-MSZ080>082-021700-
HANCOCK-HARRISON-JACKSON-LOWER JEFFERSON-LOWER LAFOURCHE-
LOWER PLAQUEMINES-LOWER ST BERNARD-LOWER TERREBONNE-ORLEANS-
ST CHARLES-ST TAMMANY-UPPER JEFFERSON-UPPER LAFOURCHE-
UPPER PLAQUEMINES-UPPER ST BERNARD-UPPER TERREBONNE-
1041 AM CDT WED MAY 2 2007

...WATERSPOUTS AND TROPICAL FUNNELS POSSIBLE TODAY...

THERE HAVE BEEN SEVERAL REPORTS OF WATERSPOUTS OR FUNNEL CLOUDS
MOVING TOWARD THE SHORELINE NEAR BILOXI. THESE FEATURES HAVE BEEN
ASSOCIATED WITH DEVELOPING LIGHT SHOWERS. WITH A MOIST ATMOSPHERE AND
FAVORABLE WIND PROFILE IN PLACE...FURTHER WATERSPOUT AND TROPICAL
FUNNEL ACTIVITY WILL BE POSSIBLE THROUGH THIS AFTERNOON. THIS
ACTIVITY WILL CONTINUE TO BE MONITORED FOR FURTHER STATEMENTS
AND OR WARNINGS.
Member Since: July 3, 2005 Posts: 426 Comments: 128654
270. GetReal
3:53 PM GMT on May 02, 2007
Hur23 check your mail!!!
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269. StormJunkie
3:48 PM GMT on May 02, 2007
23, please edit your 2:49 post so it does not stretch the blog. I know this is only a issue for IE users and not FireFox, but it is a little frustrating as some of us at work do not have the option of using FireFox.

Thanks☺
Member Since: August 17, 2005 Posts: 26 Comments: 16866
268. StormJunkie
3:38 PM GMT on May 02, 2007
Afternoon all!

As for the high, I find it interesting that everyone is giving the E coast a break just becuase the high may be strong. The high in '05 was very strong and hence all the Gulf activity. There is a more normal point for the high which would put some storms in the Gulf, but would also allow some to slip up the E coast. Just speculation here, but I do not think we will see the high persitently strong like we did in the '05 season. Again, just geussing but I think we will see something in between the '06 and '05 high.

23, do we really need all the giant images and other old pics? Can't we just link them? Not a huge deal right now, but as things heat up the pics tend to clutter and congest the blog.

ps...Will have the SST year to year comparison in my blog updated today!

Big props to John Hopkins APL site for being responsive to my issues with getting the maps☺
Member Since: August 17, 2005 Posts: 26 Comments: 16866
266. hurricane23
11:40 AM EDT on May 02, 2007
I agree getreal hopefully this pattern brakes down as we have sometime before the meat of the season is with us.

This high pressure system has been sitting in pretty much the same general area this spring and it appears that it may stay in this general position through the hurricane season. This position of the high pressure system could prevent storms recurving out to sea and keep in a western trajectory.

Here is a view from the GFS.

Badsign
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265. GetReal
3:34 PM GMT on May 02, 2007
Thanks Adrian for reminding of my thoughts, as I watched that killer hurricane approaching home. I remember thinking that I had to get my family, and important documents to a safe location!!! One should never forget!!!
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264. hurricane23
11:33 AM EDT on May 02, 2007
.
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263. GetReal
3:22 PM GMT on May 02, 2007
I believe that the position of the Bermuda High is not the only concern this hurricane season. Take note of the position, size, and strength of the Azores High.

If the bridging between these two high pressure systems remains in place, come late July and into August, the Cape Verde systems will not be able to recurve harmlessly into the central Atlantic (Fish Storms). The tropical systems will be forced to the west by the blocking highs towards the Caribbean, S. Florida, and into the GOM.
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262. Patrap
10:09 AM CDT on May 02, 2007
Super Hi-rez MODIS image of Katrina..28 Aug 2005 click to enlarge Link
Member Since: July 3, 2005 Posts: 426 Comments: 128654
261. hurricane23
11:00 AM EDT on May 02, 2007
No i pay extra for that...

Here's a view of Hurricane katrina about to move right over me.Caught it with my laptop since i could not use my pc do to no power.

katrina-adrian
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260. Levi32
6:50 AM AKDT on May 02, 2007
Wow Adrian, that's sweet. Does that same software provide the satellite and hurricane track overlays as well?
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259. Levi32
6:46 AM AKDT on May 02, 2007
Ok, the direct link to the GFS 6z run this morning for the Atlantic is here (You can't get the Caribbean without the whole Atlantic most of the time). That's only the 6z run from TODAY. It's not an updating link to the latest run. You'll have to go back to the page I gave you in my last post to get the latest runs.

Other Atlantic Tropical models include:

MET Tropical Models

Penn State E-wall has lots of models for the Atlantic
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258. hurricane23
10:48 AM EDT on May 02, 2007
Its called GRlevel3 its truly the best radar software in the market.The options are endless .

Here is a pic of wilma back in 05 a few hours before my power went out.

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257. Drakoen
2:43 PM GMT on May 02, 2007
levi: i need models for the carribean. Do you have the link?
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256. Levi32
6:38 AM AKDT on May 02, 2007
Very nice Adrian! What software to you use to make those? I'm guessing you use radar-smoothing software, but not sure how you get the overlays.
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255. hurricane23
10:37 AM EDT on May 02, 2007
This is my radar out of miami....

I'll be able to add different overlays like visible and IR to my radar.Along with current hurricane models and forcast track.

Regualar Florida view...






Keys radar along with visible.

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254. Levi32
6:36 AM AKDT on May 02, 2007
These models have animations. Just click on the loop button at the top of a product.

Most model sites have animations, you just have to hunt for them. I can post more if you want.
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253. Drakoen
2:34 PM GMT on May 02, 2007
can someone give me a link for the model animations
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252. airman45
2:32 PM GMT on May 02, 2007
Hoping for rain here too !

I wish the rain would stop! Portugal had its wettest winter in 40 years!!
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251. hurricane23
10:29 AM EDT on May 02, 2007
No doupt stormw....
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250. moonlightcowboy
2:29 PM GMT on May 02, 2007
That, does make more sense. Thanks. Good day to all, off to work.
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249. lightning10
7:24 AM PDT on May 02, 2007
I would like to mention that I find it funny that people in Georgia are complaining about there little drought. If you want a real drought come out to the southwest. Even this there so called "drought" they still had something like 10-12 inches of rain and durning the hurricane season there is a good chance of seeing a few days of good rain. Unlike the southwest where some years the monsoon doesnt hit So Cal and other areas. The rain is so isolated it doesnt do much for most of the area.
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247. Levi32
6:22 AM AKDT on May 02, 2007
Moonlightcowboy, I think I see the problem lol.

Here's the deal: I think you can see that it's hard to get the B High to reach across the ENTIRE Atlantic at the same time. That is a rare thing. So, when the B High is positioned west (close to the east US coast), then storms that form out near Africa tend to recurve in that opening on the east side of the high. When the B High is setup further to the east, then storms in the western Atlantic tend to recurve on the western side of the high.

If we have a La Nina this year, it does increase the possibility of more Cape Verde storms that trek all the way across the Atlantic from Africa to Florida. That can only happen when the Bermuda High stretches all the way across the Atlantic, and that can only happen if the upper air pattern is zonal(when the jet stream is basically an east-west line and not going up and down all the time). This is why Cape Verde storms that make it all the way across are so rare. So the storms that have the best chance of striking the US are the ones that form in the western Atlantic and Caribbean.


I hope that answers your question moonlight. I'm not very good at explaining myself lol. I tried.
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246. moonlightcowboy
2:18 PM GMT on May 02, 2007
Thanks, Levi; but, that still conflicts with some recent reading here that maintained that if the B-high were "west" like it was in 06 resulting in more storms turning out to sea on the eastern side of the high.

What am I missing here? Appreciate the posts.
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245. StormJunkie
2:17 PM GMT on May 02, 2007
Skip that....
Member Since: August 17, 2005 Posts: 26 Comments: 16866
244. Levi32
6:15 AM AKDT on May 02, 2007
LOL....the position of the B High is a very delicate thing. It's not just east-west, but north-south as well. La Nina would tend to set it further west, therefore directing more storms toward the gulf states and Florida. However, the sub-tropical jet is also moved north during La Nina, so the Bermuda High has more room to move north as well. When that happens, storms can take more northerly tracks along the southern side of the high, putting places like Georgia and the Carolinas at risk.

But if this year has a more neutral ENSO like the last couple years, anything is possible. The season will probably be active number-wise, but who knows how many of those will affect land.
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243. moonlightcowboy
2:08 PM GMT on May 02, 2007
...understand Cane. It's been my understanding that a strong la nina or neutral conditions, strengthen the possibilty of more landfalling storms to the gulf coast and Fl areas.

It's been interesting reading about the B-high possibly being more eastward, which I understand also means the likelyhood of those same coniditions.

So, I'm somewhat confused, too.
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242. TheCaneWhisperer
9:59 AM EDT on May 02, 2007
LOL! The more I read, the more confused I get! Very conflicting information out there!
241. TheCaneWhisperer
9:56 AM EDT on May 02, 2007
ENSO impacts on Hurricane Season, Florida!

Eastward Displaced High?

I read in other locations that Florida see's more scares in La Nina season which would also indicate an eastward displaced High! I will try to dig up the article that was specific about it.
240. weatherguy03
9:53 AM EDT on May 02, 2007
MissB. You definitely have the concept! Last summer over the Eastern Half of the U.S we had more of a trough setup. This moved the Bermuda High more west, thus you saw alot of storms head for Bermuda. Thats the perfect setup for all of us!! The way the High has been for the past month or so would be bad for the Gulf Coast states. So, you can see what is good and bad.
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239. Drakoen
1:52 PM GMT on May 02, 2007
what is the wave speed of the cluster of thunderstorms near the africa coast? The genisis probablility? shear?
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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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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.