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: 438 - 388

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

438. Patrap
8:01 PM CDT on May 02, 2007
Dealy Plaza Webcam..live. Link
Member Since: July 3, 2005 Posts: 421 Comments: 127633
437. hurricane23
8:58 PM EDT on May 02, 2007
THE NATIONAL WEATHER SERVICE IN FORT WORTH HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
HENDERSON COUNTY IN NORTHEAST TEXAS...

* UNTIL 900 PM CDT

* AT 752 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING DESTRUCTIVE WINDS IN
EXCESS OF 80 MPH
! THIS STORM WAS LOCATED NEAR GUN BARREL
CITY...AND MOVING EAST AT 45 MPH. THIS IS A DANGEROUS STORM! A
WIND GUST IN EXCESS OF 80 MPH WAS REPORTED IN WESTERN HENDERSON
COUNTY! SEEK IMMEDIATE SHELTER IN THE INTERIOR OF YOUR HOME.
ABANDON MOBILE HOMES FOR STURDIER SHELTER! THIS IS A DANGEROUS
SITUATION!

* THE SEVERE THUNDERSTORM WILL BE NEAR...
ATHENS BY 810 PM
BROWNSBORO BY 830 PM
COFFEE CITY AND BERRYVILLE BY 835 PM
CHANDLER BY 840 PM

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A STRONG BUILDING AND
STAY INSIDE...AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

THIS STORM HAS A HISTORY OF PRODUCING WIDESPREAD WIND DAMAGE. THIS IS
AN EXTREMELY DANGEROUS SITUATION. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS!
Member Since: May 14, 2006 Posts: 8 Comments: 13632
436. melwerle
12:59 AM GMT on May 03, 2007
Have a great night everyone - gotta hit the sack - working at 6am. Sweet dreams.
Member Since: Posts: Comments:
433. hurricane23
8:54 PM EDT on May 02, 2007
TXC119-223-231-379-467-030145-
/O.CON.KFWD.SV.W.0162.000000T0000Z-070503T0145Z/
DELTA TX-HUNT TX-HOPKINS TX-RAINS TX-VAN ZANDT TX-
737 PM CDT WED MAY 2 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR VAN ZANDT...RAINS...HOPKINS...HUNT AND DELTA COUNTIES...

AT 737 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED LINE
OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
DESTRUCTIVE WINDS IN EXCESS OF 90 MPH
. THESE STORMS WERE LOCATED
ALONG A LINE EXTENDING FROM 27 MILES WEST OF CELESTE TO 6 MILES
SOUTHWEST OF WILLS POINT TO 31 MILES SOUTHWEST OF CANTON...OR ALONG A
LINE EXTENDING FROM MCKINNEY TO 6 MILES SOUTHWEST OF WILLS POINT TO 9
MILES SOUTHWEST OF GUN BARREL CITY...MOVING NORTHEAST AT 50 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
QUINLAN...CADDO MILLS...LAKE TAWAKONI STATE PARK...WEST TAWAKONI...
EDGEWOOD...EAST TAWAKONI...GREENVILLE...LONE OAK...POINT...EMORY...
FRUITVALE...CAMPBELL...NEYLANDVILLE...WOLFE CITY...CUMBY...
COMMERCE...GRAND SALINE...VAN...SULPHUR SPRINGS...PECAN GAP...COMO...
COOPER...COOPER LAKE PARK DOCTORS CREEK...COOPER LAKE PARK SOUTH
SULPHUR AND TIRA

REMEMBER...SEVERE THUNDERSTORMS OCCASIONALLY PRODUCE TORNADOES WITH
LITTLE ADVANCE WARNING.

HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS STREETS...DITCHES AND
UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY
MAY BE WASHED OUT.

THIS STORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS AND LARGE
DAMAGING HAIL. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY
AWAY FROM WINDOWS!

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 PM CDT WEDNESDAY EVENING
FOR EASTERN TEXAS.
Member Since: May 14, 2006 Posts: 8 Comments: 13632
431. HurricaneMyles
12:51 AM GMT on May 03, 2007
melwerle..The stuff off Africa is the ITCZ. The NHC seems to not want to classify them as true tropical waves, even though everything about them shouts that they are.
Member Since: January 12, 2006 Posts: 5 Comments: 827
430. hurricane23
8:50 PM EDT on May 02, 2007
Not to funny for the people in the way of this event.
Member Since: May 14, 2006 Posts: 8 Comments: 13632
429. hurricane23
8:48 PM EDT on May 02, 2007
Nothing to worry about there for another 4-5 weeks prbably even longer.
Member Since: May 14, 2006 Posts: 8 Comments: 13632
428. StormJunkie
12:48 AM GMT on May 03, 2007
Nice software 23, will it cook dinner and could it maybe resize pictures also? ☺
Member Since: August 17, 2005 Posts: 26 Comments: 15723
427. Bamatracker
12:48 AM GMT on May 03, 2007
stuff off africa is rain...maybe some lighting
Member Since: Posts: Comments:
426. melwerle
12:46 AM GMT on May 03, 2007
damn - never thought I would miss hurricane season - glad to see everyone back sneaking around and seeing what is going on even if it IS rather early. Any clues as to what all this stuff off of africa is?
Member Since: Posts: Comments:
425. hurricane23
8:47 PM EDT on May 02, 2007
Incredible STL!90-100mph winds being repoted...



Free Image Hosting at www.ImageShack.us
Member Since: May 14, 2006 Posts: 8 Comments: 13632
424. melwerle
12:40 AM GMT on May 03, 2007
You gotta be kidding me - i have a problem flying SOUTHWEST let alone flying into hurricanes. I don't THINK so. This video makes it sound like going on a field trip. Good info though for folks who are new and don't understand the basics. She reminds me of my kid's second grade teacher...
Member Since: Posts: Comments:
423. aquak9
8:42 PM EDT on May 02, 2007
you're right, Bama. By the way, it's good to see some of the old names here, coming together. Welcome Home to all the old-timers!
Member Since: Posts: Comments:
422. Patrap
7:40 PM CDT on May 02, 2007
NOUS41 KWBC 131735
PNSWSH

SERVICE CHANGE NOTICE 07-08
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
135 PM EDT TUE MAR 7 2007

TO: FAMILY OF SERVICES /FOS/ SUBSCRIBERS...NOAA
WEATHER WIRE SERVICE /NWWS/ SUBSCRIBERS...EMERGENCY
MANAGERS WEATHER INFORMATION NETWORK /EMWIN/
SUBSCRIBERS...NOAAPORT SUBSCRIBERS...OTHER NATIONAL
WEATHER SERVICE /NWS/ CUSTOMERS AND PARTNERS...
AND NWS EMPLOYEES

FROM: THERESE Z. PIERCE
CHIEF...MARINE AND COASTAL SERVICES BRANCH

SUBJECT: ENHANCEMENT TO THE VORTEX DATA MESSAGE PRODUCT:
EFFECTIVE MAY 15 2007

ITEM F IN THE RECONNAISSANCE VORTEX DATA MESSAGE /VDM/ PRODUCT IS
THE MAXIMUM FLIGHT-LEVEL WIND OBSERVED ON THE INBOUND LEG PRIOR
TO THE STORM CENTER FIX. CURRENTLY IF A HIGHER WIND IS OBSERVED
ON THE OUTBOUND LEG IT IS REPORTED IN ITEM P ON THE SUBSEQUENT
VORTEX MESSAGE...USUALLY 2 HOURS LATER. IN ADDITION WIND MAXIMA
OBSERVED AFTER THE FINAL FIX OF A MISSION ARE NOT TRANSMITTED
THROUGH A SUBSEQUENT VDM.

EFFECTIVE ON MAY 15 2007...IF AN OBSERVED OUTBOUND WIND MAXIMUM
IS HIGHER THAN THE INBOUND WIND REPORTED IN ITEM F...THEN THE
OUTBOUND MAXIMUM WILL BE REPORTED IN THE VDM FOR THE FIX JUST
OBTAINED. IF...AFTER THE TRANSMISSION OF THE VDM...A HIGHER
OUTBOUND WIND MAXIMUM IS OBSERVED...THEN A CORRECTED VORTEX
MESSAGE WILL BE TRANSMITTED AT THE CONCLUSION OF THE OUTBOUND LEG
WITH THE UPDATED OUTBOUND MAXIMUM. OUTBOUND WIND MAXIMA WILL BE
REPORTED IN ITEM P


DOC AND DOD HURRICANE RECONNAISSANCE AIRCRAFT PROVIDE VORTEX DATA
MESSAGES /VDM/ AS PART OF THE NATIONAL HURRICANE OPERATIONS PLAN
/NHOP/. THESE PRODUCTS AND ASSOCIATED HEADERS ARE PROVIDED IN
TABLES 1 AND 2 FOR THE ATLANTIC AND PACIFIC HURRICANE BASINS
RESPECTIVELY.

TABLE 1. VDM FOR THE ATLANTIC HURRICANE BASIN

FEDERAL AGENCY WMO HEADING

DOC URNT12 KWBC
DOD URNT12 KNHC

TABLE 2. VDM FOR THE EAST...CENTRAL...AND WEST PACIFIC HURRICANE
BASINS

FEDERAL AGENCY WMO HEADING

DOC URPN12 KWBC
DOD UPPN12 KNHC

COMPLETE VDM FORMATS ARE PROVIDED IN THE NHOP...SEE TABLE 5-2 AND
FIGURE 5-6. THE NHOP IS ONLINE AT /USE LOWER CASE LETTERS/:

HTTP://WWW.OFCM.GOV/NHOP

THE 2006 NHOP IS NOW POSTED ON THE INTERNET. THE 2007 NHOP WILL
BE POSTED BY JUNE 1 2007.

IF YOU HAVE ANY QUESTIONS...PLEASE CONTACT:

CHRIS SISKO
TROPICAL PREDICTION CENTER
NATIONAL HURRICANE CENTER
Member Since: July 3, 2005 Posts: 421 Comments: 127633
421. Bamatracker
12:40 AM GMT on May 03, 2007
wohooo!!! Movie time!!!
Member Since: Posts: Comments:
420. Bamatracker
12:39 AM GMT on May 03, 2007
dont worry about it aquak....we all just need to party it up!!
Member Since: Posts: Comments:
419. Patrap
7:37 PM CDT on May 02, 2007
Get yer popcorn. Were going into the storm with NASA and the Hurricane Hunters.
Member Since: July 3, 2005 Posts: 421 Comments: 127633
418. aquak9
8:37 PM EDT on May 02, 2007
no fighting on my end, just didn't understand edith's post.

Be glad to delete my own post (in reference to my blog) if that is what's needed.
Member Since: Posts: Comments:
417. Bamatracker
12:37 AM GMT on May 03, 2007
dont know who's blog...he/she just wanted it moved!!
Member Since: Posts: Comments:
415. aquak9
8:35 PM EDT on May 02, 2007
Meaning, my reference to my own blog?

help please
Member Since: Posts: Comments:
414. melwerle
12:33 AM GMT on May 03, 2007
where is stormw? Night isn't complete...also - we're missing a few other folks...
Member Since: Posts: Comments:
413. Patrap
7:35 PM CDT on May 02, 2007
The 60 hour GOM SST's model..Link
Member Since: July 3, 2005 Posts: 421 Comments: 127633
412. Bamatracker
12:34 AM GMT on May 03, 2007
he wanted the blog moved
Member Since: Posts: Comments:
411. Tazmanian
5:32 PM PDT on May 02, 2007
Posted By: edith at 5:31 PM PDT on May 02, 2007.

move your blog, jackass


oh are you calling a jackass?
Member Since: Posts: Comments:
410. aquak9
8:33 PM EDT on May 02, 2007
Edith? didn't understand your post.
Member Since: Posts: Comments:
409. Patrap
7:33 PM CDT on May 02, 2007
Back in Black..
Member Since: July 3, 2005 Posts: 421 Comments: 127633
407. hurricane23
8:30 PM EDT on May 02, 2007
Severe weather in south florida but staying away from heavily populated areas.
Member Since: May 14, 2006 Posts: 8 Comments: 13632
406. Bamatracker
12:30 AM GMT on May 03, 2007
woohooo!!!! reunion party!!!! the 07 season is starting to cook!!
Member Since: Posts: Comments:
403. aquak9
8:30 PM EDT on May 02, 2007
Learn about the frightening fire situation in Georgia and Florida at AquaK9's blog.
Member Since: Posts: Comments:
402. aquak9
8:29 PM EDT on May 02, 2007
Ahhh..hello patrap and rays. Long time, no see.
Member Since: Posts: Comments:
401. Patrap
7:28 PM CDT on May 02, 2007


Learn about hurricane hazards and what you can do to help protect yourself, your family, and your property.
National Hurricane Center
Member Since: July 3, 2005 Posts: 421 Comments: 127633
400. crackerlogic
12:26 AM GMT on May 03, 2007
If W and Gore are going to be on Springer, I got money that Jeb is sleeping with Tipper
399. Patrap
7:28 PM CDT on May 02, 2007
4
Member Since: July 3, 2005 Posts: 421 Comments: 127633
398. melwerle
12:27 AM GMT on May 03, 2007
i'm wondering if the pres is going to take his shirt off and wander around the stage (like I haev never watched THAT before - how embarressing).
Member Since: Posts: Comments:
397. aquak9
8:27 PM EDT on May 02, 2007
STORMTOP will be back.

You KNOW that's written in stone.
Member Since: Posts: Comments:
396. Raysfan70
8:27 PM EDT on May 02, 2007
I'm here.
Member Since: Posts: Comments:
395. franck
12:23 AM GMT on May 03, 2007
Somebody please tell me when that is going to air. I wonder if they will fight, and Jerry's goons will have to stand between them?
Member Since: Posts: Comments:
393. melwerle
12:20 AM GMT on May 03, 2007
oh geez SJ - I FORGOT that It is WRITTEN IN STONE. oh don't get me started...

The new storm is coming and it's going to hit on Tues at 7:32 am. It is WRITTEN IN STONE. (As I say with my sandals on and my deadhead outfit.)

Everyone go and get two of everything and build an ark.

Member Since: Posts: Comments:
392. DDR
12:20 AM GMT on May 03, 2007
Thanks all !!
Member Since: Posts: Comments:
391. franck
12:18 AM GMT on May 03, 2007
Anybody hear anything about the President appearing on Jerry Springer... something about discussing global warming with Al Gore? Any body know anything about that?
Member Since: Posts: Comments:
390. edith
12:14 AM GMT on May 03, 2007
I had a thought. It's not that evolution is wrong and Creationism is improper, ... God is evolving and science is uncovering.
Member Since: Posts: Comments:
389. melwerle
12:17 AM GMT on May 03, 2007
ok - then several people have already been struck. What's the outlook for the stuff going on now?
Member Since: Posts: Comments:
388. franck
12:14 AM GMT on May 03, 2007
Did you guys see the President on 'American Idol'?
Dang I missed that.
Member Since: Posts: Comments:

Viewing: 438 - 388

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
66 °F
Overcast