Science.gov

Sample records for 8-hour ozone nonattainment

  1. 40 CFR 51.914 - What new source review requirements apply for 8-hour ozone nonattainment areas?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... apply for 8-hour ozone nonattainment areas? 51.914 Section 51.914 Protection of Environment... OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.914 What new source review requirements apply for 8-hour ozone nonattainment areas?...

  2. 40 CFR 51.914 - What new source review requirements apply for 8-hour ozone nonattainment areas?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.914 What new source review requirements apply for 8-hour ozone nonattainment areas? The... apply for 8-hour ozone nonattainment areas? 51.914 Section 51.914 Protection of...

  3. 40 CFR 51.914 - What new source review requirements apply for 8-hour ozone nonattainment areas?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.914 What new source review requirements apply for 8-hour ozone nonattainment areas? The... apply for 8-hour ozone nonattainment areas? 51.914 Section 51.914 Protection of...

  4. 40 CFR 51.914 - What new source review requirements apply for 8-hour ozone nonattainment areas?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.914 What new source review requirements apply for 8-hour ozone nonattainment areas? The... apply for 8-hour ozone nonattainment areas? 51.914 Section 51.914 Protection of...

  5. 40 CFR 51.914 - What new source review requirements apply for 8-hour ozone nonattainment areas?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... apply for 8-hour ozone nonattainment areas? 51.914 Section 51.914 Protection of Environment... Standard § 51.914 What new source review requirements apply for 8-hour ozone nonattainment areas? The requirements for new source review for the 8-hour ozone standard are located in § 51.165 of this part....

  6. 40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September...

  7. 40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September...

  8. 40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September...

  9. 40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September...

  10. 40 CFR 51.918 - Can any SIP planning requirements be suspended in 8-hour ozone nonattainment areas that have air...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... suspended in 8-hour ozone nonattainment areas that have air quality data that meets the NAAQS? 51.918... 8-hour Ozone National Ambient Air Quality Standard § 51.918 Can any SIP planning requirements be suspended in 8-hour ozone nonattainment areas that have air quality data that meets the NAAQS? Upon...

  11. 40 CFR 51.918 - Can any SIP planning requirements be suspended in 8-hour ozone nonattainment areas that have air...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... suspended in 8-hour ozone nonattainment areas that have air quality data that meets the NAAQS? 51.918... 8-hour Ozone National Ambient Air Quality Standard § 51.918 Can any SIP planning requirements be suspended in 8-hour ozone nonattainment areas that have air quality data that meets the NAAQS? Upon...

  12. 40 CFR 51.918 - Can any SIP planning requirements be suspended in 8-hour ozone nonattainment areas that have air...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... suspended in 8-hour ozone nonattainment areas that have air quality data that meets the NAAQS? 51.918... 8-hour Ozone National Ambient Air Quality Standard § 51.918 Can any SIP planning requirements be suspended in 8-hour ozone nonattainment areas that have air quality data that meets the NAAQS? Upon...

  13. 40 CFR 51.918 - Can any SIP planning requirements be suspended in 8-hour ozone nonattainment areas that have air...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... suspended in 8-hour ozone nonattainment areas that have air quality data that meets the NAAQS? 51.918... 8-hour Ozone National Ambient Air Quality Standard § 51.918 Can any SIP planning requirements be suspended in 8-hour ozone nonattainment areas that have air quality data that meets the NAAQS? Upon...

  14. 75 FR 79302 - Determination of Nonattainment and Reclassification of the Dallas/Fort Worth 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ... nonattainment area failed to attain the 1997 8-hour ozone national ambient air quality standard (NAAQS or... review of complete, quality assured and certified ambient air quality monitoring data for the 2007-2009 monitoring period that are available in the EPA Air Quality System (AQS) database. As a result of this...

  15. 40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., AND SUBMITTAL OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection...

  16. 40 CFR 51.918 - Can any SIP planning requirements be suspended in 8-hour ozone nonattainment areas that have air...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... suspended in 8-hour ozone nonattainment areas that have air quality data that meets the NAAQS? 51.918 Section 51.918 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... 8-hour Ozone National Ambient Air Quality Standard § 51.918 Can any SIP planning requirements...

  17. 76 FR 54412 - Determination of Nonattainment and Reclassification of the Baltimore 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... ambient air quality data for the 2009 ozone season. (See 76 FR 13289.) On June 4, 2010, EPA approved a..., and individuals with a pre-existing respiratory disease, such as asthma. On March 27, 2008 (73 FR... standard. B. The Baltimore Area On April 30, 2004 (69 FR 23951), EPA finalized its...

  18. 40 CFR 51.906 - Redesignation to nonattainment following initial designations for the 8-hour NAAQS.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality... subsequently redesignated to nonattainment for the 8-hour ozone NAAQS, any absolute, fixed date applicable...

  19. 40 CFR 51.906 - Redesignation to nonattainment following initial designations for the 8-hour NAAQS.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality... subsequently redesignated to nonattainment for the 8-hour ozone NAAQS, any absolute, fixed date applicable...

  20. 40 CFR 51.906 - Redesignation to nonattainment following initial designations for the 8-hour NAAQS.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality... subsequently redesignated to nonattainment for the 8-hour ozone NAAQS, any absolute, fixed date applicable...

  1. 40 CFR 51.906 - Redesignation to nonattainment following initial designations for the 8-hour NAAQS.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality... subsequently redesignated to nonattainment for the 8-hour ozone NAAQS, any absolute, fixed date applicable...

  2. 40 CFR 51.906 - Redesignation to nonattainment following initial designations for the 8-hour NAAQS.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality... subsequently redesignated to nonattainment for the 8-hour ozone NAAQS, any absolute, fixed date applicable...

  3. 75 FR 47746 - Determination of Nonattainment and Reclassification of the Dallas/Fort Worth 1997 8-hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-09

    ... is more protective than the previous 1-hour ozone standard (62 FR 38855) that was established by EPA in 1979. We revoked the 1-hour ozone standard effective June 15, 2005. See 40 CFR 50.9(b) and 69 FR...). See 69 FR 23857 (April 30, 2004).\\1\\ Ambient air quality monitoring data for the 3-year period...

  4. 8 HOUR OZONE DESIGN VALUE FOR 1998-2000

    EPA Science Inventory

    The Ozone design value is based on the average of the annual 4th highest dailsy 8-hour maximum over a 3-year period (1998-2000) in this case. This is a human health based metric. Ozone causes respiratory illness in humans.

  5. 78 FR 47572 - Disapproval of State Implementation Plan; Infrastructure Requirements for the 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-06

    ... 8-Hour Ozone National Ambient Air Quality Standard; Montana AGENCY: Environmental Protection Agency... the Clean Air Act (CAA) for the National Ambient Air Quality Standards (NAAQS) promulgated for ozone... Agency. (iii) The initials NAAQS mean or refer to National Ambient Air Quality Standards. (iv)...

  6. 40 CFR 51.908 - What modeling and attainment demonstration requirements apply for purposes of the 8-hour ozone...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... demonstration requirements apply for purposes of the 8-hour ozone NAAQS? 51.908 Section 51.908 Protection of..., AND SUBMITTAL OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient... purposes of the 8-hour ozone NAAQS? (a) What is the attainment demonstration requirement for an...

  7. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ambient air quality standards for ozone. 50.10 Section 50.10 Protection of Environment ENVIRONMENTAL....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  8. 40 CFR 51.916 - What are the requirements for an Ozone Transport Region under the 8-hour NAAQS?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false What are the requirements for an Ozone... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.916 What are the requirements for an Ozone Transport Region under the 8-hour NAAQS? (a) In...

  9. 40 CFR 52.387 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-hour ozone and PM2.5 NAAQS. 52.387 Section 52.387 Protection of Environment ENVIRONMENTAL PROTECTION... § 52.387 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On March 13, 2007, the State...)(D)(i) interstate transport requirements of the Clean Air Act for the 1997 8-hour ozone and...

  10. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ambient air quality standards for ozone. 50.10 Section 50.10 Protection of Environment ENVIRONMENTAL....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  11. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ambient air quality standards for ozone. 50.10 Section 50.10 Protection of Environment ENVIRONMENTAL....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  12. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ambient air quality standards for ozone. 50.10 Section 50.10 Protection of Environment ENVIRONMENTAL....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  13. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ambient air quality standards for ozone. 50.10 Section 50.10 Protection of Environment ENVIRONMENTAL....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  14. 40 CFR 52.387 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-hour ozone and PM2.5 NAAQS. 52.387 Section 52.387 Protection of Environment ENVIRONMENTAL PROTECTION... § 52.387 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On March 13, 2007, the State...)(D)(i) interstate transport requirements of the Clean Air Act for the 1997 8-hour ozone and...

  15. 40 CFR 52.387 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-hour ozone and PM2.5 NAAQS. 52.387 Section 52.387 Protection of Environment ENVIRONMENTAL PROTECTION... § 52.387 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On March 13, 2007, the State...)(D)(i) interstate transport requirements of the Clean Air Act for the 1997 8-hour ozone and...

  16. 40 CFR 52.387 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-hour ozone and PM2.5 NAAQS. 52.387 Section 52.387 Protection of Environment ENVIRONMENTAL PROTECTION... § 52.387 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On March 13, 2007, the State...)(D)(i) interstate transport requirements of the Clean Air Act for the 1997 8-hour ozone and...

  17. 40 CFR 52.387 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-hour ozone and PM2.5 NAAQS. 52.387 Section 52.387 Protection of Environment ENVIRONMENTAL PROTECTION... § 52.387 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On March 13, 2007, the State...)(D)(i) interstate transport requirements of the Clean Air Act for the 1997 8-hour ozone and...

  18. 40 CFR 52.1393 - Interstate Transport Declaration for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the 1997 8-hour ozone and PM2.5 NAAQS. 52.1393 Section 52.1393 Protection of Environment ENVIRONMENTAL... (CONTINUED) Montana § 52.1393 Interstate Transport Declaration for the 1997 8-hour ozone and PM2.5 NAAQS. The... Section 110(a)(2)(D)(i) for the 8-hour ozone and PM2.5 NAAQS promulgated in July 1997. The...

  19. 40 CFR 52.1393 - Interstate Transport Declaration for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the 1997 8-hour ozone and PM2.5 NAAQS. 52.1393 Section 52.1393 Protection of Environment ENVIRONMENTAL... (CONTINUED) Montana § 52.1393 Interstate Transport Declaration for the 1997 8-hour ozone and PM2.5 NAAQS. The... Section 110(a)(2)(D)(i) for the 8-hour ozone and PM2.5 NAAQS promulgated in July 1997. The...

  20. 40 CFR 52.97 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. 52.97 Section 52.97 Protection of Environment ENVIRONMENTAL PROTECTION....97 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On February 7, 2008, the...

  1. 40 CFR 52.2499 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. 52.2499 Section 52.2499 Protection of Environment ENVIRONMENTAL PROTECTION...) Washington § 52.2499 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On January 17, 2007,...

  2. 40 CFR 51.916 - What are the requirements for an Ozone Transport Region under the 8-hour NAAQS?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.916 What are the requirements for an Ozone Transport Region under the 8-hour NAAQS? (a) In General... 40 Protection of Environment 2 2012-07-01 2012-07-01 false What are the requirements for an...

  3. 40 CFR 51.908 - What modeling and attainment demonstration requirements apply for purposes of the 8-hour ozone...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., AND SUBMITTAL OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.908 What modeling and attainment demonstration requirements apply for... demonstration requirements apply for purposes of the 8-hour ozone NAAQS? 51.908 Section 51.908 Protection...

  4. 40 CFR 51.908 - What modeling and attainment demonstration requirements apply for purposes of the 8-hour ozone...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., AND SUBMITTAL OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.908 What modeling and attainment demonstration requirements apply for... demonstration requirements apply for purposes of the 8-hour ozone NAAQS? 51.908 Section 51.908 Protection...

  5. 40 CFR 51.916 - What are the requirements for an Ozone Transport Region under the 8-hour NAAQS?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.916 What are the requirements for an Ozone Transport Region under the 8-hour NAAQS? (a) In General... 40 Protection of Environment 2 2013-07-01 2013-07-01 false What are the requirements for an...

  6. 40 CFR 51.908 - What modeling and attainment demonstration requirements apply for purposes of the 8-hour ozone...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., AND SUBMITTAL OF IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.908 What modeling and attainment demonstration requirements apply for... demonstration requirements apply for purposes of the 8-hour ozone NAAQS? 51.908 Section 51.908 Protection...

  7. 40 CFR 51.916 - What are the requirements for an Ozone Transport Region under the 8-hour NAAQS?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.916 What are the requirements for an Ozone Transport Region under the 8-hour NAAQS? (a) In General... 40 Protection of Environment 2 2014-07-01 2014-07-01 false What are the requirements for an...

  8. 40 CFR 51.916 - What are the requirements for an Ozone Transport Region under the 8-hour NAAQS?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.916 What are the requirements for an Ozone Transport Region under the 8-hour NAAQS? (a) In General... 40 Protection of Environment 2 2011-07-01 2011-07-01 false What are the requirements for an...

  9. 40 CFR 52.2499 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. 52.2499 Section 52.2499 Protection of Environment ENVIRONMENTAL PROTECTION...) Washington § 52.2499 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On January 17, 2007,...

  10. 40 CFR 52.97 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. 52.97 Section 52.97 Protection of Environment ENVIRONMENTAL PROTECTION....97 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On February 7, 2008, the...

  11. 40 CFR 52.2499 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. 52.2499 Section 52.2499 Protection of Environment ENVIRONMENTAL PROTECTION...) Washington § 52.2499 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On January 17, 2007,...

  12. 40 CFR 52.97 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. 52.97 Section 52.97 Protection of Environment ENVIRONMENTAL PROTECTION....97 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On February 7, 2008, the...

  13. 40 CFR 52.97 - Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. 52.97 Section 52.97 Protection of Environment ENVIRONMENTAL PROTECTION....97 Interstate Transport for the 1997 8-hour ozone and PM2.5 NAAQS. On February 7, 2008, the...

  14. 40 CFR 51.913 - How do the section 182(f) NOX exemption provisions apply for the 8-hour NAAQS?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.913... designated nonattainment for the 8-hour ozone NAAQS and for any area in a section 184 ozone transport region...) A section 182(f) NOX exemption granted for the 1-hour ozone standard does not relieve the area...

  15. 40 CFR 51.913 - How do the section 182(f) NOX exemption provisions apply for the 8-hour NAAQS?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.913... designated nonattainment for the 8-hour ozone NAAQS and for any area in a section 184 ozone transport region...) A section 182(f) NOX exemption granted for the 1-hour ozone standard does not relieve the area...

  16. 40 CFR 51.913 - How do the section 182(f) NOX exemption provisions apply for the 8-hour NAAQS?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.913... designated nonattainment for the 8-hour ozone NAAQS and for any area in a section 184 ozone transport region...) A section 182(f) NOX exemption granted for the 1-hour ozone standard does not relieve the area...

  17. 75 FR 68733 - Approval and Promulgation of One-Year Extension for Attaining the 1997 8-Hour Ozone Standard for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-09

    ... Revision; State of New Jersey'' proposed April 23, 2010 (75 FR 21197) and final rulemaking August 3, 2010... Control Measure'' proposed July 22, 2010 (75 FR 42672); and (2) The maximum 4th highest daily 8-hour.... Table 1--Monitoring Data for 8-Hour Ozone in the Philadelphia Area 4th Max 8-hr Site ID...

  18. 75 FR 9781 - Determination of Nonattainment and Reclassification of the Atlanta, Georgia, 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ... standard, was approved by EPA on March 6, 2008 (73 FR 12013). However, EPA inadvertently excluded Hall... this action. Statutory and Executive Order Reviews Under Executive Order 12866 (58 FR 51735, October 4... Use'' (66 FR 28355, May 22, 2001). This action merely corrects an inadvertent error of omission in...

  19. 75 FR 57220 - Rule To Implement the 1997 8-Hour Ozone National Ambient Air Quality Standard: New Source Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-20

    ..., e-mail address, and telephone and fax numbers. Questions concerning the August 24, 2010 (75 FR 51960... holding the public hearing was published in the Federal Register on August 24, 2010 (75 FR 51960), and is... AGENCY 40 CFR Part 51 RIN 2060-AP30 Rule To Implement the 1997 8-Hour Ozone National Ambient Air...

  20. 78 FR 34965 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Lima 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; Ohio; Lima 1997 8... the request by Ohio to revise the Lima, Ohio 1997 8-hour ozone maintenance air quality...

  1. 40 CFR 52.1393 - Interstate Transport Declaration for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the 1997 8-hour ozone and PM2.5 NAAQS. 52.1393 Section 52.1393 Protection of Environment ENVIRONMENTAL... dated replacement pages for the Montana Interstate Transport Rule Declaration. The new set of pages were sent as replacement for the set of undated pages submitted earlier with the February 12, 2007 Record...

  2. 40 CFR 52.1393 - Interstate Transport Declaration for the 1997 8-hour ozone and PM2.5 NAAQS.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the 1997 8-hour ozone and PM2.5 NAAQS. 52.1393 Section 52.1393 Protection of Environment ENVIRONMENTAL... dated replacement pages for the Montana Interstate Transport Rule Declaration. The new set of pages were sent as replacement for the set of undated pages submitted earlier with the February 12, 2007 Record...

  3. 77 FR 43521 - Final Rule To Implement the 1997 8-Hour Ozone National Ambient Air Quality Standard...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-25

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 81 RIN 2060-AO96 Final Rule To Implement the 1997 8-Hour Ozone National Ambient Air Quality Standard: Classification of Areas That Were Initially Classified Under Subpart 1; Revision of the Anti-Backsliding Provisions To Address...

  4. 76 FR 10815 - Approval and Promulgation of Determination of Attainment for the 1997 8-Hour Ozone Standard...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-28

    ... 12898 (59 FR 7629, February 16, 1994). In addition, this proposed 8-hour ozone clean NAAQS data... that the area has attained the NAAQS during the 2008-2010 monitoring period. On March 27, 2008 (73 FR... by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October 4,...

  5. 40 CFR 51.908 - What modeling and attainment demonstration requirements apply for purposes of the 8-hour ozone...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... classified as moderate or higher under subpart 2 pursuant to § 51.903? An area classified as moderate or... area subject only to subpart 1 in accordance with § 51.902(b)? An area subject to § 51.902(b) shall be... demonstration requirements apply for purposes of the 8-hour ozone NAAQS? 51.908 Section 51.908 Protection...

  6. 40 CFR 51.241 - Nonattainment areas for carbon monoxide and ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 2 2011-07-01 2011-07-01 false Nonattainment areas for carbon monoxide... Intergovernmental Consultation Agency Designation § 51.241 Nonattainment areas for carbon monoxide and ozone. (a) For each AQCR or portion of an AQCR in which the national primary standard for carbon monoxide...

  7. 40 CFR 51.241 - Nonattainment areas for carbon monoxide and ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Nonattainment areas for carbon monoxide... Intergovernmental Consultation Agency Designation § 51.241 Nonattainment areas for carbon monoxide and ozone. (a) For each AQCR or portion of an AQCR in which the national primary standard for carbon monoxide...

  8. 40 CFR 51.241 - Nonattainment areas for carbon monoxide and ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Nonattainment areas for carbon monoxide... Intergovernmental Consultation Agency Designation § 51.241 Nonattainment areas for carbon monoxide and ozone. (a) For each AQCR or portion of an AQCR in which the national primary standard for carbon monoxide...

  9. 40 CFR 51.241 - Nonattainment areas for carbon monoxide and ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Nonattainment areas for carbon monoxide... Intergovernmental Consultation Agency Designation § 51.241 Nonattainment areas for carbon monoxide and ozone. (a) For each AQCR or portion of an AQCR in which the national primary standard for carbon monoxide...

  10. 40 CFR 51.241 - Nonattainment areas for carbon monoxide and ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Nonattainment areas for carbon monoxide... Intergovernmental Consultation Agency Designation § 51.241 Nonattainment areas for carbon monoxide and ozone. (a) For each AQCR or portion of an AQCR in which the national primary standard for carbon monoxide...

  11. 78 FR 34906 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Lima 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... 1.36 Total 18.46 17.41 15.07 3.39 Table 2--Total NOX Emissions With MOVES2010a Mobile Emissions in... attainment of the 1997 8-hour ozone standard effective June 15, 2007 (72 FR 27648), and MOBILE6.2-based...(c) of the CAA. See the official release of the MOVES2010 emissions model (75 FR 9411-9414)...

  12. 40 CFR 52.1989 - Interstate Transport for the 1997 8-hour ozone NAAQS and 1997 PM2.5 NAAQS.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Interstate Transport for the 1997 8-hour ozone NAAQS and 1997 PM2.5 NAAQS. 52.1989 Section 52.1989 Protection of Environment ENVIRONMENTAL... (CONTINUED) Oregon § 52.1989 Interstate Transport for the 1997 8-hour ozone NAAQS and 1997 PM2.5 NAAQS....

  13. 40 CFR 52.977 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the Baton Rouge 1-hour ozone nonattainment area has attained the 1-hour ozone National Ambient Air... determined that the Baton Rouge 8-hour ozone nonattainment area has attained the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS). Under the provisions of 40 CFR 51.918 this determination...

  14. 40 CFR 52.977 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the Baton Rouge 1-hour ozone nonattainment area has attained the 1-hour ozone National Ambient Air... determined that the Baton Rouge 8-hour ozone nonattainment area has attained the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS). Under the provisions of 40 CFR 51.918 this determination...

  15. 40 CFR 52.977 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the Baton Rouge 1-hour ozone nonattainment area has attained the 1-hour ozone National Ambient Air... determined that the Baton Rouge 8-hour ozone nonattainment area has attained the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS). Under the provisions of 40 CFR 51.918 this determination...

  16. 40 CFR 52.977 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the Baton Rouge 1-hour ozone nonattainment area has attained the 1-hour ozone National Ambient Air... determined that the Baton Rouge 8-hour ozone nonattainment area has attained the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS). Under the provisions of 40 CFR 51.918 this determination...

  17. 77 FR 30160 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: Nonattainment Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ... areas for the 2008 ozone NAAQS until March 12, 2011, pending the NAAQS reconsideration.\\2\\ See 75 FR... apply to the areas that are designated as nonattainment for the 2008 ozone NAAQS. See 77 FR 8197. The... table for the 1997 ozone NAAQS. See 77 FR at 8201-02. \\7\\ The upper thresholds of the Marginal,...

  18. 78 FR 65877 - Approval and Promulgation of Implementation Plans; Atlanta, Georgia 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... Georgia's ROP plan for the 1-hour ozone NAAQS for the Atlanta Area on April 26, 1999. See 64 FR 20196. \\3..., Paulding, and Rockdale. See 56 FR 56694, November 6, 1991. \\4\\ Seven additional ``ring'' counties were.... These additional counties are: Barrow, Bartow, Carroll, Hall, Newton, Spalding, and Walton. See 69...

  19. 78 FR 32135 - Approval and Promulgation of Implementation Plans; Atlanta, Georgia 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... the 1-hour ozone NAAQS for the Atlanta Area on April 26, 1999. See 64 FR 20196. \\3\\ The 13-County.... See 56 FR 56694, November 6, 1991. \\4\\ Seven additional ``ring'' counties were added to the original 1... counties include: Barrow, Bartow, Carroll, Hall, Newton, Spalding, and Walton. See 69 FR 23857, April...

  20. 40 CFR 51.915 - What emissions inventory requirements apply under the 8-hour NAAQS?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... emissions inventories for these areas, the ozone-relevant data element requirements under 40 CFR part 51... nonattainment area subject only to title I, part D, subpart 1 of the Act in accordance with § 51.902(b), the... apply under the 8-hour NAAQS? 51.915 Section 51.915 Protection of Environment ENVIRONMENTAL...

  1. 40 CFR 51.902 - Which classification and nonattainment area planning provisions of the CAA shall apply to areas...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.902 Which classification and... with a 1-hour ozone design value equal to or greater than 0.121 ppm at the time the Administrator signs...) Covered under subpart 1 (CAA). An area designated nonattainment for the 8-hour ozone NAAQS with a...

  2. 40 CFR 51.902 - Which classification and nonattainment area planning provisions of the CAA shall apply to areas...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.902 Which classification and... with a 1-hour ozone design value equal to or greater than 0.121 ppm at the time the Administrator signs...) Covered under subpart 1 (CAA). An area designated nonattainment for the 8-hour ozone NAAQS with a...

  3. Trends analyses of 30 years of ambient 8 hour ozone and precursor monitoring data in the South Central U.S.: progress and challenges.

    PubMed

    Sather, Mark E; Cavender, Kevin

    2016-07-13

    In the last 30 years ambient ozone concentrations have notably decreased in the South Central U.S. Yet, current ambient ozone concentrations measured over the past three years 2013-2015 in this area of the U.S. are not meeting the U.S. 2015 8 hour ozone standard of 70 parts per billion (ppb). This paper provides an update on long-term trends analyses of ambient 8 hour ozone and ozone precursor monitoring data collected over the past 30 years (1986-2015) in four South Central U.S. cities, following up on two previously published reviews of 20 and 25 year trends for these cities. All four cities have benefitted from national ozone precursor controls put in place during the 1990s and 2000s involving cleaner vehicles (vehicle fleet turnover/replacement over time), cleaner fuels, cleaner gasoline and diesel engines, and improved inspection/maintenance programs for existing vehicles. Additional ozone precursor emission controls specific to each city are detailed in this paper. The controls have resulted in impressive ambient ozone and ambient ozone precursor concentration reductions in the four South Central U.S. cities over the past 30 years, including 31-70% ambient nitrogen oxides (NOx) concentration declines from historical peaks to the present, 43-72% volatile organic compound (VOC) concentration declines from historical peaks to the present, a related 45-76% VOC reactivity decline for a subset of VOC species from historical peaks to the present, and an 18-38 ppb reduction in city 8 hour ozone design value concentrations. A new challenge for each of the four South Central U.S. cities will be meeting the U.S. 2015 8 hour ozone standard of 70 ppb. PMID:27282109

  4. 75 FR 80420 - Reasonable Further Progress Requirements for the 1997 8-Hour Ozone National Ambient Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-22

    ... discussion of EPA's rationale for applying this interpretation in the Phase 2 Rule, see 70 FR at 71647- 49... FR 71612, November 29, 2005). \\2\\ The memorandum is available on the EPA Technology and Transfer... approach for crediting reductions from outside nonattainment areas (``outside'' reductions). See 72...

  5. 75 FR 43069 - Approval of One-Year Extension for Attaining the 1997 8-Hour Ozone Standard in the Baltimore...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ... Nonattainment Area 4th Max 8-HR Site ID County/State Year (ppm) 24-003-0014 Anne Arundel, MD 2009 0.070 24-005.... Statutory and Executive Order Reviews Under Executive Order 12866 (58 FR 51735, October 4, 1993), this... Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 28355 (May...

  6. 76 FR 33647 - Approval and Promulgation of Determination of Attainment for the 1997 8-Hour Ozone Standard...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-09

    .... Louis (MO-IL) metropolitan nonattainment area on February 28, 2011 (76 FR 10815). A detailed discussion... that the area has attained the NAAQS during the 2008- 2010 monitoring period. On March 27, 2008 (73 FR... 12866 (58 FR 51735, October 4, 1993); Does not impose an information collection burden under...

  7. 77 FR 28423 - Final Rule To Implement the 1997 8-Hour Ozone National Ambient Air Quality Standard...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ... addition to being available in the docket, an electronic copy of this notice is also available on the World... 13211: Actions That Significantly Affect Energy Supply, Distribution, or Use I. National Technology... rulemaking (74 FR 2936). \\1\\ 74 FR 2936, January 16, 2009. III. This Action A. Classification of 8-Hour...

  8. 77 FR 21690 - Approval and Promulgation of Air Quality Implementation Plan for 1997 8-Hour Ozone Standard; Arizona

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-11

    ... National Ambient Air Quality Standards for Ozone'', January 6, 2010 and 75 FR 2938 (January 19, 2010). On...-hour standard of 0.08 ppm \\1\\ (62 FR 33856). EPA revised the ozone standard after considering... standards by lowering the level for both to 0.075 ppm (73 FR 16436, Mar. 27, 2008). B. The Phoenix-Mesa...

  9. 76 FR 2829 - Approval and Promulgation of Air Quality Implementation Plans; Virginia; Adoption of 8-hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-18

    ... NAAQS for ozone on March 27, 2008 (73 FR 16436). II. Summary of SIP Revision On September 27, 2010, the... Budget under Executive Order 12866 (58 FR 51735, October 4, 1993); Does not impose an information...); Does not have Federalism implications as specified in Executive Order 13132 (64 FR 43255, August...

  10. 75 FR 8331 - Adequacy Status of the Cincinnati, Ohio/Indiana Submitted 8-Hour Ozone Redesignation and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-24

    ... submitted SIP budgets in our July 1, 2004, preamble starting at 69 FR 40038, and we used the information in... (NOx) as precursors to ozone in the Ohio and Indiana portions of the Cincinnati-Hamilton, OH/KY/IN... (tpd), for VOCs and NOx for the Ohio and Indiana portions of the Cincinnati, Ohio area are as...

  11. 40 CFR 51.902 - Which classification and nonattainment area planning provisions of the CAA shall apply to areas...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... area planning provisions of the CAA shall apply to areas designated nonattainment for the 1997 8-hour NAAQS? 51.902 Section 51.902 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.902 Which classification...

  12. 40 CFR 51.902 - Which classification and nonattainment area planning provisions of the CAA shall apply to areas...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... area planning provisions of the CAA shall apply to areas designated nonattainment for the 1997 8-hour NAAQS? 51.902 Section 51.902 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.902 Which classification...

  13. Eastern Texas Air Quality Forecasting System to Support TexAQS-II and 8-hour Ozone Modeling

    NASA Astrophysics Data System (ADS)

    Byun, D. W.

    2005-12-01

    The main objective of the Second Texas Air Quality Study (TexAQS-II) for 2005 and 2006 is to understand emissions and processes associated with the formation and transport of ozone and regional haze in Texas. The target research area is the more populated eastern half of the state, roughly from Interstate 35 eastward. Accurate meteorological and photochemical modeling efforts are essential to support this study and further enhance modeling efforts for establishing the State Implementation Plan (SIP) by Texas Commission on Environmental Quality (TCEQ). An air quality forecasting (AQF) system for Eastern Texas has been developed to provide these data and to further facilitate retrospective simulations to allow for model improvement and increased understanding of ozone episodes and emissions. We perform two-day air quality forecasting simulations with the 12-km Eastern Texas regional domain, and the 4-km Houston-Galveston area (HGA) domain utilizing a 48-CPU Beowulf Linux computer system. The dynamic boundary conditions are provided by the 36-km resolution conterminous US (CONUS) domain CMAQ simulations. Initial meteorological conditions are provided by the daily ETA forecast results. The results of individual runs are stored and made available to researchers and state and local officials via internet to study the patterns of air quality and its relationship to weather conditions and emissions. The data during the pre- and post-processing stages are in tens of gigabytes and must be managed efficiently during both the actual real-time and the subsequent computation periods. The nature of these forecasts and the time at which the initial data is available necessitates that models be executed within tight deadlines. A set of complex operational scripts is used to allow automatic operation of the data download, sequencing processors, performing graphical analysis, building database archives, and presenting on the web.

  14. 40 CFR 52.2037 - Control strategy plans for attainment and rate-of-progress: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR 51.918, EPA has determined that Pittsburgh-Beaver Valley 8-hour ozone nonattainment area has...-hour ozone standard of 40 CFR 50.9: the attainment demonstration and reasonably available control... 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR 51.918, suspends...

  15. 40 CFR 52.2037 - Control strategy plans for attainment and rate-of-progress: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CFR 51.918, EPA has determined that Pittsburgh-Beaver Valley 8-hour ozone nonattainment area has...-hour ozone standard of 40 CFR 50.9: the attainment demonstration and reasonably available control... 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR 51.918, suspends...

  16. Volatile organic compound emissions from usaf wastewater treatment plants in ozone nonattainment areas. Master's thesis

    SciTech Connect

    Ouellette, B.A.

    1994-09-01

    In accordance with the 1990 Clean Air Act Amendments (CAAA), this research conducts an evaluation of the potential emission of volatile organic compounds (VOCs) from selected Air Force wastewater treatment plants. Using a conservative mass balance analysis and process specific simulation models, volatile organic emission estimates are calculated for four individual facilities--Edwards AFB, Luke AFB, McGuire AFB, and McClellan AFB--which represent a cross section of the current inventory of USAF wastewater plants in ozone nonattainment areas. From these calculations, maximum facility emissions are determined which represent the upper limit for the potential VOC emissions from these wastewater plants. Based on the calculated emission estimates, each selected wastewater facility is evaluated as a potential major stationary source of volatile organic emissions under both Title I of the 1990 CAAA and the plant's governing Clean Air Act state implementation plan. Next, the potential impact of the specific volatile organics being emitted is discussed in terms of their relative reactivity and individual contribution to tropospheric ozone formation. Finally, a relative comparison is made between the estimated VOC emissions for the selected wastewater facilities and the total VOC emissions for their respective host installations.

  17. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data... secondary ambient air quality standards for ozone specified in § 50.10 are met at an ambient ozone...

  18. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data... secondary ambient air quality standards for ozone specified in § 50.10 are met at an ambient ozone...

  19. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data... secondary ambient air quality standards for ozone specified in § 50.10 are met at an ambient ozone...

  20. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data... secondary ambient air quality standards for ozone specified in § 50.10 are met at an ambient ozone...

  1. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data... secondary ambient air quality standards for ozone specified in § 50.10 are met at an ambient ozone...

  2. 77 FR 26950 - Designation of Areas for Air Quality Planning Purposes; California; Western Mojave Desert Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-08

    ...'' nonattainment for the 1997 8-hour ozone NAAQS.\\1\\ See 69 FR 23858, at 23884 (April 30, 2004) and 40 CFR 81.305... FR 29073, May 20, 2008), and reclassified the Sacramento Metro area from ``Serious'' to ``Severe-15'' nonattainment effective June 4, 2010 (75 FR 24409, May 5, 2010). \\3\\ CARB subsequently submitted a SIP...

  3. Ozone nonattainment under the Clean Air Act. Hearing before the Subcommittee on Technology, Environment and Aviation of the Committee on Science, Space, and Technology, U.S. House of Representatives, One Hundred Third Congress, Second Session, July 8, 1994

    SciTech Connect

    1994-12-31

    The hearing addresses ozone nonattainment under the Clean Air Act. Southeastern Wisconsin is a designated ozone non-attainment area under amendments to the Act of 1990. Preliminary results of a Lake Michigan Ozone study seem to indicate that much of the pollution causing high levels of ozone come from several hundred miles away. The witnesses examine plans to cope with this situation. Statements of government and industry officials are included along with documents submitted for the record.

  4. A Procedure for Inter-Comparing the Skill of Regional-Scale Air Quality Model Simulations of Daily Maximum 8-Hour Ozone Concentrations

    EPA Science Inventory

    An operational model evaluation procedure is described to quantitatively assess the relative skill among several regionalscale air quality models simulating various percentiles of the cumulative frequency distribution of observed daily maximum 8-h ozone concentrations. Bootstrap ...

  5. 77 FR 8197 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: Nonattainment Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-14

    ... set at a more stringent level. \\1\\ See 73 FR 16436. \\2\\ The secondary ozone standard, designed to... 1-hour ozone NAAQS, see 56 FR 56694. \\8\\ See 40 CFR Appendix I. \\9\\ Referred to as the Phase 1 Rule... the 1997 ozone NAAQS. (See 69 FR 23954). The Phase 1 rule also established comprehensive...

  6. 40 CFR 52.2037 - Control strategy plans for attainment and rate-of-progress: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CFR 51.918, EPA has determined that Pittsburgh-Beaver Valley 8-hour ozone nonattainment area has...-hour ozone standard of 40 CFR 50.9: the attainment demonstration and reasonably available control... Federal Register citations affecting § 52.2037, see the List of CFR Sections Affected, which appears...

  7. 40 CFR 51.915 - What emissions inventory requirements apply under the 8-hour NAAQS?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.915 What... emissions inventories for these areas, the ozone-relevant data element requirements under 40 CFR part...

  8. 40 CFR 51.915 - What emissions inventory requirements apply under the 8-hour NAAQS?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.915 What... emissions inventories for these areas, the ozone-relevant data element requirements under 40 CFR part...

  9. 40 CFR 51.915 - What emissions inventory requirements apply under the 8-hour NAAQS?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.915 What... emissions inventories for these areas, the ozone-relevant data element requirements under 40 CFR part...

  10. 40 CFR 51.915 - What emissions inventory requirements apply under the 8-hour NAAQS?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.915 What... emissions inventories for these areas, the ozone-relevant data element requirements under 40 CFR part...

  11. 78 FR 9596 - Approval and Promulgation of Implementation Plans; New Jersey and New York Ozone Attainment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... attainment of the 1997 8-hour ozone NAAQS during this monitoring period. See 77 FR 36163, 77 FR 47533, 77 FR 17341, and 74 FR 63993. EPA is aware that preliminary ambient air quality monitoring data for 2012 may... moderate nonattainment areas. On December 11, 2012 (77 FR 73570), EPA published a notice of...

  12. 40 CFR 51.1102 - Classification and nonattainment area planning provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Provisions for Implementation of the 2008 Ozone National Ambient Air Quality Standards § 51.1102 Classification and nonattainment area planning provisions. An area designated nonattainment for the 2008...

  13. 40 CFR 51.1102 - Classification and nonattainment area planning provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Provisions for Implementation of the 2008 Ozone National Ambient Air Quality Standards § 51.1102 Classification and nonattainment area planning provisions. An area designated nonattainment for the 2008...

  14. 40 CFR 51.913 - How do the section 182(f) NOX exemption provisions apply for the 8-hour NAAQS?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... provisions apply for the 8-hour NAAQS? 51.913 Section 51.913 Protection of Environment ENVIRONMENTAL... IMPLEMENTATION PLANS Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.913... petition the Administrator for an exemption from NOX obligations under section 182(f) for any...

  15. Maps depicting nonattainment areas pursuant to Section 107 of the Clean Air Act - 1985

    SciTech Connect

    Yarn, J.; Beal, W.; Tate, C.

    1985-09-01

    The report is a detailed mapping of the United States depicting those areas nonattaining the National Ambient Air Quality Standards for carbon monoxide, nitrogen dioxide, ozone, sulfur dioxide, and total suspended particulates. It includes nonattainment area maps and supporting lists from Federal Register publications for final actions through September 1, 1985.

  16. 78 FR 28497 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Canton-Massillon 1997 8-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-15

    ... attainment of the 1997 8-hour ozone standard effective June 15, 2007, (72 FR 27648). MOBILE6.2-based budgets... the CAA. See the official release of the MOVES2010 emissions model (75 FR 9411-9414) for background... of MOVES2010 in March 2010 (75 FR 9411). Use of the MOVES model is required for regional...

  17. "OZONE SOURCE APPORTIONMENT IN CMAQ'

    EPA Science Inventory

    Ozone source attribution has been used to support various policy purposes including interstate transport (Cross State Air Pollution Rule) by U.S. EPA and ozone nonattainment area designations by State agencies. Common scientific applications include tracking intercontinental tran...

  18. Title I implementation: Status report on nonattainment areas

    SciTech Connect

    Kenkeremath, L.D.; Snyder, T.C.

    1993-01-01

    Key provisions of Title I of the Clean Air Act Amendments of 1990 (CAAA) focus on bringing cities and other areas into attainment of the National Ambient Air Quality Standards for ozone, carbon monoxide (CO), and fine particulates (PM-10). The CAAA`s new classification scheme for pollutant nonattainment areas is based on the relative severity of pollution in these areas and determines the stringency of control measures and the dates by which attainment of the standards will be required. The US Environmental Protection Agency`s (EPA`s) final rule on air quality designations and classifications, published in late 1991, shows that ozone pollution remains a persistent problem; the number of counties that fail to meet the ozone standard has sharply increased since 1987. In contrast, incidence of PM-10 pollution has decreased; many counties have achieved the PM-10 standard since 1987. Nationwide, the number of CO nonattainment areas has increased, though not dramatically. Many of the new Title I requirements focus on the role of nitrogen oxides (NO{sub x}) in the formation of ground-level ozone. In ozone nonattainment areas and ozone transport regions, Title I generally requires major sources of NO{sub x} to have the same control measures as those that apply to major sources of volatile organic compounds (VOCs). This requirement compels state regulators to adopt an integrated VOC/NO{sub x} control strategy. The NO{sub x} emission standards proposed by state regulators are considerably more stringent than those given in federal guidelines. Both the EPA and the states plan to allow the use of multifacility emissions averaging in state NO{sub x} control strategies, thereby providing industry flexibility. Proposed federal Economic Incentive Program (EIP) rules would also allow sources in states with approved EIPs to use mobile source emission reduction credits to meet certain stationary source emission reduction requirements.

  19. Title I implementation: Status report on nonattainment areas

    SciTech Connect

    Kenkeremath, L.D.; Snyder, T.C.

    1993-01-01

    Key provisions of Title I of the Clean Air Act Amendments of 1990 (CAAA) focus on bringing cities and other areas into attainment of the National Ambient Air Quality Standards for ozone, carbon monoxide (CO), and fine particulates (PM-10). The CAAA's new classification scheme for pollutant nonattainment areas is based on the relative severity of pollution in these areas and determines the stringency of control measures and the dates by which attainment of the standards will be required. The US Environmental Protection Agency's (EPA's) final rule on air quality designations and classifications, published in late 1991, shows that ozone pollution remains a persistent problem; the number of counties that fail to meet the ozone standard has sharply increased since 1987. In contrast, incidence of PM-10 pollution has decreased; many counties have achieved the PM-10 standard since 1987. Nationwide, the number of CO nonattainment areas has increased, though not dramatically. Many of the new Title I requirements focus on the role of nitrogen oxides (NO[sub x]) in the formation of ground-level ozone. In ozone nonattainment areas and ozone transport regions, Title I generally requires major sources of NO[sub x] to have the same control measures as those that apply to major sources of volatile organic compounds (VOCs). This requirement compels state regulators to adopt an integrated VOC/NO[sub x] control strategy. The NO[sub x] emission standards proposed by state regulators are considerably more stringent than those given in federal guidelines. Both the EPA and the states plan to allow the use of multifacility emissions averaging in state NO[sub x] control strategies, thereby providing industry flexibility. Proposed federal Economic Incentive Program (EIP) rules would also allow sources in states with approved EIPs to use mobile source emission reduction credits to meet certain stationary source emission reduction requirements.

  20. 40 CFR 52.2332 - Control Strategy: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...: Ozone. Determinations—EPA is determining that, as of July 18, 1995, the Salt Lake and Davis Counties... the ozone NAAQS is monitored in the Salt Lake and Davis Counties ozone nonattainment area,...

  1. Ozone attainment: A different perspective

    SciTech Connect

    Beck, W.B. )

    1988-01-01

    Recent attention on the ozone non-attainment issue has been focused on Washington. Both Congress and the EPA have made efforts at addressing the post-1987 crisis in the many non-attainment areas. In contrast to the political activity, this paper presents some interesting technical perspectives on ozone attainment for many areas of the U.S.. Issues such as transport, climate and natural ozone sources are discussed in the context of exceedance frequency for several geographical areas of the country.

  2. Environmental compliance guide. Guidance manual for Department of Energy compliance with the Clean Air Act: nonattainment areas

    SciTech Connect

    1982-09-01

    The purpose of this manual is to identify information requirements associated with air quality permit applications in areas for which ambient pollutant levels currently exceed the national ambient air quality standards (nonattainment areas). The manual is to be used by project managers at the US Department of Energy (DOE), in conjunction with the DOE Environmental Compliance Guide, to provide preliminary estimates of information required to obtain air quality permits for DOE projects. An analysis of nonattainment area permitting found that permitting of all sources in such areas is done on the state or local levels; the Environmental Protection Agency does not grant permits in nonattainment areas. As a result, Federal information requirements for permitting in nonattainment areas are somewhat vague. To provide a more realistic picture of nonattainment area permitting, selected state and local regulations were surveyed, and were found to contain more detail on the information required for permit approval. The most potentially demanding information requirements associated with nonattainment area permitting are the determination of Lowest Achievable Emission Rate, the negotiation of external emission offsets, and the consideration of the environmental impacts of project alternatives in ozone and carbon monoxide nonattainment areas. In any state, a few information requirements for nonattainment area permitting are likely to overlap with information requirements of other permitting processes, such as those in the Prevention of Significant Deterioration procedure. These requirements are emissions data and air quality modeling and its associated input data requirements (meteorology, topography, etc.).

  3. 40 CFR 51.1102 - Classification and nonattainment area planning provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Classification and nonattainment area planning provisions. 51.1102 Section 51.1102 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Provisions for Implementation of the 2008 Ozone National Ambient Air Quality Standards §...

  4. Maps depicting nonattainment areas pursuant to Section 107 of the Clean Air Act - 1984

    SciTech Connect

    Yarn, J.; Beal, W.; Tate, C.

    1984-07-01

    This report is a detailed mapping of the United States depicting those areas not attaining the National Ambient Air Quality Standards for carbon monoxide, nitrogen dioxide, ozone, sulfur dioxide and total suspended particulates. It includes non-attainment area maps and supporting lists from Federal Register publications for final actions through July 1, 1984.

  5. 40 CFR 51.907 - For an area that fails to attain the 8-hour NAAQS by its attainment date, how does EPA interpret...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.907 For an area that... 40 Protection of Environment 2 2012-07-01 2012-07-01 false For an area that fails to attain the 8... the CAA? 51.907 Section 51.907 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

  6. 40 CFR 51.907 - For an area that fails to attain the 8-hour NAAQS by its attainment date, how does EPA interpret...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.907 For an area that... 40 Protection of Environment 2 2010-07-01 2010-07-01 false For an area that fails to attain the 8... the CAA? 51.907 Section 51.907 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

  7. 78 FR 17902 - Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ... December 28, 2012. \\1\\ On March 27, 2008 (73 FR 16436), EPA promulgated a revised 8-hour ozone standard of... nonattainment for the 2008 8-hour ozone standard (77 FR 30088). This rulemaking relates only to the 1997 8-hour... Basin as a nonattainment area (SDAB nonattainment area) for the photochemical oxidant NAAQS. See 43...

  8. 75 FR 42672 - Approval and Promulgation of Implementation Plans; New Jersey; 8-hour Ozone Control Measures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-22

    ... conditionally approved. See 74 FR 22837 (May 15, 2009). If EPA approves this proposed SIP revision, the RACT... Subchapter 24 occurred on January 25, 2006 (71 FR 4045). EPA had previously approved Subchapter 24 provisions... percent control. Subchapter 26 also regulates the VOC content/vapor pressure of surface-preparation...

  9. EMISSION INVENTORIES TO SUPPORT DEVELOPMENT OF PM2.5 AND 8-HOUR OZONE IMPLEMENTATION POLICIES

    EPA Science Inventory

    The product will be a set of historical and projected emission inventories. The projected inventories will represent a number of alternative regulatory scenarios. Inventories will be in the form required by CMAQ/Models-3 and other air quality models, and will be accompanied by n...

  10. 78 FR 32222 - Approval and Promulgation of Implementation Plans; Atlanta, Georgia 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... 73 FR 16436. The current action, however, is being taken to address requirements under the earlier... Barrow, Bartow, Carroll, Cherokee, Clayton, Cobb, Coweta, Dekalb, Douglas, Fayette, Forsyth,...

  11. 78 FR 32613 - Disapproval of State Implementation Plan; Infrastructure Requirements for the 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ... Order 13045: Protection of Children from Environmental Health Risks and Safety Risks (62 FR 19885, April... Order 12898 (59 FR 7629, February 16, 1994), establishes federal executive policy on environmental... 0.12 parts per million (ppm) to 0.08 ppm (62 FR 38856). By statute, SIPs meeting the requirements...

  12. 78 FR 34903 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... Table 2--Total NOX Emissions With MOVES2010a Mobile Emissions in the Ohio portion of Wheeling West... effective June 15, 2007 (72 FR 27644). MOBILE6.2-based budgets for the Ohio portion of the area were... section 176(c) of the CAA. See the official release of the MOVES2010 emissions model (75 FR 9411-9414)...

  13. 75 FR 80340 - Approval and Promulgation of Implementation Plans; New Jersey; 8-Hour Ozone Control Measures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-22

    ... approved. For additional information, see the proposed rulemaking published on July 22, 2010 (75 FR 42672... the Act and EPA's regulations. Administrative Correction On August 3, 2010, 75 FR 45483, EPA took... Management and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993); Does not impose...

  14. 75 FR 17915 - Agency Information Collection Activities; Proposed Collection; Comment Request; 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-08

    ... keeping necessary to maintain the rule. The rule was proposed on June 2, 2003, (68 FR 32802) and promulgated in two Phases: Phase 1 published on April 30, 2004, (69 FR 23951) and Phase 2 published on November 29, 2005 (70 FR 71612). The preamble to the proposed and final regulations addressed...

  15. 78 FR 45188 - Agency Information Collection Activities; Proposed Collection; Comment Request; 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-26

    ... the rule. The rule was proposed on June 2, 2003 (68 FR 32802), and promulgated in two Phases: Phase 1 published on April 30, 2004 (69 FR 23951), and Phase 2 published on November 29, 2005 (70 FR 71612). The... preamble to the final Phase 2 rule stated that an ICR would be prepared (70 FR 71692). The rule...

  16. Ozone

    MedlinePlus

    ... Earth's surface. It shields us from the sun's ultraviolet rays. Part of the good ozone layer is ... enough good ozone, people may get too much ultraviolet radiation. This may increase the risk of skin ...

  17. Ozone

    MedlinePlus

    ... reactive form of oxygen. In the upper atmosphere, ozone forms a protective layer that shields us from the sun’s ultraviolet rays. At ground level, ozone is a harmful air pollutant and a primary ...

  18. Ozone

    MedlinePlus

    Ozone is a gas. It can be good or bad, depending on where it is. "Good" ozone occurs naturally about 10 to 30 miles above ... the sun's ultraviolet rays. Part of the good ozone layer is gone. Man-made chemicals have destroyed ...

  19. 77 FR 56775 - Approval and Promulgation of Implementation Plans; California; Determinations of Attainment for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-14

    ...EPA is making several determinations relating to 1997 8-hour ozone nonattainment areas in California. First, EPA is determining that six 8-hour ozone nonattainment areas in California (Amador and Calaveras Counties, Chico, Kern County, Mariposa and Tuolumne Counties, Nevada County, and Sutter County) (``six CA areas'') attained the 1997 8-hour ozone national ambient air quality standard......

  20. 40 CFR 52.2332 - Control Strategy: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Control Strategy: Ozone. 52.2332...: Ozone. Determinations—EPA is determining that, as of July 18, 1995, the Salt Lake and Davis Counties ozone nonattainment area has attained the ozone standard based on air quality monitoring data from...

  1. 40 CFR 52.2332 - Control Strategy: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Control Strategy: Ozone. 52.2332...: Ozone. Determinations—EPA is determining that, as of July 18, 1995, the Salt Lake and Davis Counties ozone nonattainment area has attained the ozone standard based on air quality monitoring data from...

  2. 40 CFR 52.2332 - Control Strategy: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Control Strategy: Ozone. 52.2332...: Ozone. Determinations—EPA is determining that, as of July 18, 1995, the Salt Lake and Davis Counties ozone nonattainment area has attained the ozone standard based on air quality monitoring data from...

  3. 40 CFR 52.2332 - Control Strategy: Ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control Strategy: Ozone. 52.2332...: Ozone. Determinations—EPA is determining that, as of July 18, 1995, the Salt Lake and Davis Counties ozone nonattainment area has attained the ozone standard based on air quality monitoring data from...

  4. 40 CFR 52.977 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy and regulations: Ozone... and regulations: Ozone. Determination of Attainment. Effective March 12, 2010 EPA has determined the Baton Rouge 1-hour ozone nonattainment area has attained the 1-hour ozone National Ambient Air...

  5. 40 CFR 52.2235 - Control strategy: Ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.2235... strategy: Ozone. (a) Determination—EPA is determining that, as of August 8, 1995, the Nashville ozone nonattainment area has attained the ozone standard and that the reasonable further progress and...

  6. Minorities and air quality non-attainment areas: A preliminary geo-demographic analysis

    SciTech Connect

    Wernette, D.; Nieves, L.

    1991-06-01

    A major section of the Clean Air Act Amendments (CAAA) focuses on reducing air pollution through extending and modifying the provisions for states and localities with US Environmental Protection Agency (EPA)-designated non-attainment areas. Specifically, Title 1 of the CAAA is concerned with non-attainment areas, as defined relative to the National Ambient Air Quality Standards for atmospheric ozone, carbon monoxide, and particulate matter; Title 2 is concerned with mobile sources or air pollution, which produce carbon monoxide, contribute to ozone concentrations, and in the past have been a major source of airborne lead; and Title 4 is concerned with acid deposition, mainly due to sulfur dioxide emissions. This paper has its origin in the question of the potential benefits for minorities--relative to the majority non-Black, non-Hispanic population--of reductions in air pollution that may result from these amendments. It is part of a larger effort to identify and assess the costs and benefits of the CAAA for minorities, relative to the majority population. The focus of this paper centers on comparing Black and Hispanic populations to White, non-Hispanic populations living in EPA-designated non-attainment area counties in the contiguous United States, which excludes Alaska and Hawaii. Subsequent comparisons of majority populations with Native Americans and Asian-Americans will include these two states.

  7. 77 FR 41186 - Proposed Consent Decree, Clean Air Act Citizen Suit

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-12

    ... requirement for the Charlotte-Gastonia-Rock Hill 1997 8-hour ozone nonattainment area. 77 FR 24382. On May 4... nonattainment area. 77 FR 26441. On May 18, 2012, EPA took final action to approve the SIP submittals submitted... Hill 1997 8- ] hour ozone nonattainment area. 77 FR 29540. The proposed consent decree requires...

  8. 77 FR 4901 - Designation of Areas for Air Quality Planning Purposes; Maryland; Determination of Nonattainment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-01

    ... respiratory disease, such as asthma. On March 27, 2008 (73 FR 16436), EPA promulgated a revised 8-hour ozone... at pino.maria@epa.gov . SUPPLEMENTARY INFORMATION: I. Background On September 1, 2011 (76 FR 54412... be used to establish motor vehicle emissions budgets in all new SIPs. (See 75 FR 9411.)...

  9. A 4.8 hour periodicity in the spectra of Cyg X-3

    NASA Technical Reports Server (NTRS)

    Becker, R. H.; Robinson-Saba, J. L.; Boldt, E. A.; Holt, S. S.; Pravdo, S. H.; Serlemitsos, P. J.; Swank, J. H.

    1978-01-01

    The X-ray spectra from three observations of the X-ray binary Cyg X-3 by the cosmic X-ray spectroscopy experiment on OSO can be represented by power-law continua with strong iron line emission. Comparisons of spectra taken within the same observation at various phases of the 4.8 hour period reveal a relative excess of low energy X-ray emission near zero phase (i.e. the minimum) of the 4.8 hour modulation. In addition, the centroid of the line emission is observed to vary in phase with the 4.8 hour cycle. The possibility of persistent thermal X-ray emission from material surrounding the binary system is introduced in an effort to account for the observed effects.

  10. Ozone Air Quality Impacts of Shale Gas Development in South Texas Urban Areas

    NASA Astrophysics Data System (ADS)

    Chang, C.; Liao, K.

    2013-12-01

    Recent technological advances, mainly horizontal drilling and hydraulic fracturing, and continued drilling in shale, have increased domestic production of oil and gas in the United State (U.S.). However, shale gas developments could also affect the environment and human health, particularly in areas where oil and gas developments are new activities. This study is focused on the impacts of shale gas developing activities on summertime ozone air quality in South Texas urban areas since many of them are already ozone nonattainment areas. We use an integrated approach to investigate the ozone air quality impact of the shale gas development in South Texas urban areas. They are: (1) satellite measurement of precursors, (2) observations of ground-level ozone concentrations, and (3) air mass trajectory modeling. Nitrogen dioxide (NO2) is an important precursor to ozone formation, and summertime average tropospheric nitrogen dioxide (NO2) column densities measured by the National Aeronautics and Space Administration's Ozone Monitoring Instrument increased in the South Texas shale area (i.e., the Eagle Ford Shale area) in 2011 and 2012 as compared to 2008-2010. The U.S. Environmental Protection Agency's ground-level observations showed summertime average and peak ozone (i.e., the 4th highest daily maximum 8-hour average ozone) concentrations slightly increased from 2010 to 2012 in Austin and San Antonio. However, the frequencies of peak ozone concentrations above the 75ppb ozone standard have been significantly increasing since 2011 in Austin and San Antonio. It is expected to increase the possibilities of violating the ozone National Ambient Air Quality Standard (NAAQS) for South Texas urban areas in the future. The results of trajectory modeling showed air masses transported from the southeastern Texas could reach Austin and San Antonio and confirmed that emissions from the Eagle Ford Shale area could affect ozone air quality in South Texas urban areas in 2011 and 2012

  11. Potential impacts of Title I nonattainment on the electric power industry: A Chicago case study (Phase 2)

    SciTech Connect

    Fernau, M.E.; Makofske, W.J.; South, D.W.

    1993-06-01

    This study uses version IV of the Urban Airshed Model (UAM-IV) to examine the potential impacts of Title I (nonattainment) and Title IV (acid rain) of the Clean Air Act Amendments of 1990 (CAAA) on the utility industry. The UAM is run for a grid that covers the Commonwealth Edison Power Pool and encompasses the greater Chicago area and surrounding rural areas. Meteorological conditions are selected from an ozone (O{sub 3}) episode on July 5 and 6, 1988.

  12. 40 CFR 52.930 - Control strategy: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control strategy: Ozone. 52.930 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Kentucky § 52.930 Control strategy: Ozone. (a) The VOC..., Campbell and Kenton Counties) ozone nonattainment area. The demonstration of attainment of the...

  13. 40 CFR 52.2038 - Rate of Progress Plans: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Rate of Progress Plans: Ozone. 52.2038... Progress Plans: Ozone. (a) EPA grants full approval to Pennsylvania's 15 Percent Rate of Progress Plan for the Pittsburgh-Beaver Valley ozone nonattainment area, submitted by the Secretary of the...

  14. 40 CFR 52.2038 - Rate of Progress Plans: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Rate of Progress Plans: Ozone. 52.2038... Progress Plans: Ozone. (a) EPA grants full approval to Pennsylvania's 15 Percent Rate of Progress Plan for the Pittsburgh-Beaver Valley ozone nonattainment area, submitted by the Secretary of the...

  15. 40 CFR 52.2038 - Rate of Progress Plans: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Rate of Progress Plans: Ozone. 52.2038... Progress Plans: Ozone. (a) EPA grants full approval to Pennsylvania's 15 Percent Rate of Progress Plan for the Pittsburgh-Beaver Valley ozone nonattainment area, submitted by the Secretary of the...

  16. 40 CFR 52.2038 - Rate of Progress Plans: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Rate of Progress Plans: Ozone. 52.2038... Progress Plans: Ozone. (a) EPA grants full approval to Pennsylvania's 15 Percent Rate of Progress Plan for the Pittsburgh-Beaver Valley ozone nonattainment area, submitted by the Secretary of the...

  17. 40 CFR 52.2038 - Rate of Progress Plans: Ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Rate of Progress Plans: Ozone. 52.2038... Progress Plans: Ozone. (a) EPA grants full approval to Pennsylvania's 15 Percent Rate of Progress Plan for the Pittsburgh-Beaver Valley ozone nonattainment area, submitted by the Secretary of the...

  18. 40 CFR 52.930 - Control strategy: Ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.930 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Kentucky § 52.930 Control strategy: Ozone. (a) The VOC..., Campbell and Kenton Counties) ozone nonattainment area. The demonstration of attainment of the...

  19. 75 FR 15391 - Approval and Promulgation of Air Quality Implementation Plans; Texas; Revision to Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-29

    ... Control Volatile Organic Compound Emissions in the Houston/Galveston/Brazoria 8-Hour Ozone Nonattainment... revision adds additional requirements to control volatile organic compound (VOC) emissions from...

  20. Ozone

    SciTech Connect

    Not Available

    1988-06-01

    The author discusses the debate over whether concern about a hole in the ozone layer in Antarctic is real or science fiction. There is a growing consensus that efforts must be taken to protect the ozone layer. The issue now is not whether chlorofluorocarbons (CFCs) should be controlled and regulated but how much and how soon. The United States has urged that the production of dangerous CFCs, and any other chemicals that affect the ozone layer, be restricted immediately to current levels and that their use be reduced 95 percent over the next decade. The American position was too strong for many European nations and the Japanese. Negotiations at an international conference on the matter broke down. The breakdown is due in part to a more acute concern for environmental matters in the United States than exists in many countries. Meanwhile CFCs are linked to another environmental problem that equally threatens the world - the Greenhouse Effect. The earth is in a natural warming period, but man could be causing it to become even warmer. The Greenhouse Effect could have a catastrophic impact on mankind, although nothing has been proven yet.

  1. 76 FR 17343 - Approval and Promulgation of Implementation Plans; Nevada; Determination of Attainment for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-29

    ... nonattainment area has attained the 1997 8-hour ozone national ambient air quality standards (NAAQS). This... Ozone Nonattainment Area B. Determination of Attainment C. Ambient Air Quality Monitoring Data III. What... monitored attainment of the 1997 8-hour ozone NAAQS. Preliminary air quality monitoring data available...

  2. 75 FR 8571 - Approval and Promulgation of Air Quality Implementation Plans; Rhode Island; Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-25

    ...) moderate 1997 8-hour ozone nonattainment area has attained the 1997 8-hour National Ambient Air Quality...-hour ozone NAAQS based on the three most recent years (2001-2003) of air quality data. The entire state of Rhode Island was designated as a moderate ozone nonattainment area. Recent air quality...

  3. 40 CFR 52.1125 - Emission inventories.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... emission inventories for the Springfield nonattainment area and the Massachusetts portion of the Boston... Springfield nonattainment area and the Massachusetts portion of the Boston-Lawrence-Worcester nonattainment... emissions for calendar year 2002 from the Boston-Lawrence-Worcester moderate 8-hour ozone nonattainment...

  4. 40 CFR 52.1125 - Emission inventories.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... emission inventories for the Springfield nonattainment area and the Massachusetts portion of the Boston... Springfield nonattainment area and the Massachusetts portion of the Boston-Lawrence-Worcester nonattainment... emissions for calendar year 2002 from the Boston-Lawrence-Worcester moderate 8-hour ozone nonattainment...

  5. Motor cortex excitability changes within 8 hours after ischaemic stroke may predict the functional outcome.

    PubMed

    Di Lazzaro, V; Oliviero, A; Profice, P; Saturno, E; Pilato, F; Tonali, P

    1999-06-01

    Motor evoked potentials after magnetic transcranial stimulation and the excitability of the motor cortex to increasing magnetic stimulus intensities were evaluated in six patients with hemiparesis after ischaemic stroke within 8 hours after stroke. The latencies of motor evoked potentials were normal in all patients. After stimulation of the ischaemic hemisphere we obtained responses comparable with the contralateral ones in two patients (mean NIH score 2 (SD 0)) and this group was completely asymptomatic after 15 days (NIH score 0). In four patients the excitability of the motor cortex involved by the ischaemia was reduced and magnetic motor threshold was higher than that of the spared motor cortex. This finding was associated with a poor motor recovery and the NIH score after 15 days was unchanged (NIH score 1.75 (SD 1.5)). The present data suggest that the evaluation of the excitability of motor cortex may offer a mean of predicting functional outcome following stroke. PMID:10461555

  6. 75 FR 43114 - Approval of One-Year Extension for Attaining the 1997 8-Hour Ozone Standard in the Baltimore...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ... quality standard (NAAQS). This extension is based in part on air quality data for the 4th highest daily 8..., EPA is approving the State's request as a direct final rule without prior proposal because the Agency... Street, Philadelphia, Pennsylvania 19103. Copies of the State submittal are available at...

  7. 76 FR 3838 - Approval and Promulgation of One-Year Extension for Attaining the 1997 8-Hour Ozone Standard for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-21

    ... attainment date be extended to June 15, 2011. On November 9, 2010 (75 FR 68733), EPA proposed to approve New...).'' IV. Statutory and Executive Order Reviews Under Executive Order 12866 (58 FR 51735, October 4, 1993...'' (66 FR 28355 (May 22, 2001)). This action merely finds that an area has qualified for a...

  8. 75 FR 68736 - Approval of One-Year Extension for Attaining the 1997 8-Hour Ozone Standard for the Delaware...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-09

    ...'' subject to review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October... Executive Order 13132 (64 FR 43255, August 10, 1999); Is not an economically significant regulatory action based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997); ] Is...

  9. 76 FR 3840 - Approval of One-Year Extension for Attaining the 1997 8-Hour Ozone Standard for the Delaware...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-21

    ...'' (66 FR 28355, May 22, 2001). This action merely approves state law as meeting Federal requirements and... November 9, 2010 (75 FR 68736), EPA published a notice of proposed rulemaking (NPR) for the States. The NPR... Executive Order Reviews A. General Requirements Under Executive Order 12866 (58 FR 51735, October 4,...

  10. 76 FR 13289 - Approval of One-Year Extension for Attaining the 1997 8-Hour Ozone Standard in the Baltimore...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-11

    ..., 2010 (75 FR 43114), EPA published a notice of proposed rulemaking (NPR) for the State of Maryland. The... Energy Supply, Distribution, or Use (66 FR 28355, May 22, 2001). This action merely approves State law as... 12866 (58 FR 51735, October 4, 1993), this action is not a ``significant regulatory action''...

  11. 76 FR 2859 - Approval and Promulgation of Air Quality Implementation Plans; Virginia; Adoption of 8-hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-18

    ... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; Virginia; Adoption... available on the Internet. If you ] submit an electronic comment, EPA recommends that you include your name... statute. Certain other material, such as copyrighted material, is not placed on the Internet and will...

  12. 77 FR 35285 - Approval of Air Quality Implementation Plan; Arizona; Attainment Plan for 1997 8-Hour Ozone Standard

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-13

    ... Order Reviews I. Proposed Action On April 11, 2012 (70 FR 21690), EPA proposed to approve the ``Eight... Budget under Executive Order 12866 (58 FR 51735, October 4, 1993); Does not impose an information...); Does not have Federalism implications as specified in Executive Order 13132 (64 FR 43255, August...

  13. 75 FR 16456 - Adequacy Status of the Beaumont-Port Arthur, TX Maintenance Plan; 8-Hour Ozone Motor Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ...; Transportation Conformity Rule Amendments: Response to Court Decision and Additional Rule Changes'' (69 FR 40004... been made, pursuant to 40 CFR 93.104(e). See, 73 FR 4419 (January 24, 2008). Authority: 42 U.S.C. 7401... motor vehicle emissions budgets (MVEB) in the Beaumont-Port Arthur, Texas (BPA) Redesignation...

  14. 78 FR 7429 - Adequacy Status of the Dallas-Fort Worth, TX Reasonable Further Progress 8-Hour Ozone Motor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ...: Response to Court Decision and Additional Rule Changes'' (69 FR 40004). Please note that an adequacy review..., pursuant to 40 CFR 93.104(e). See, 73 FR 4419 (January 24, 2008). Authority: 42 U.S.C. 7401 et seq. Dated... are provided in Table 1: Table 1--Dallas-Fort Worth Reasonable Further Progress NOX and VOC MVEBs...

  15. 76 FR 28223 - Adequacy Status of the Baton Rouge, Louisiana Maintenance Plan 8-Hour Ozone Motor Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-16

    ... Additional Rule Changes'' (69 FR 40004). Please note that an adequacy review is separate from EPA's... the new MVEB if the demonstration has not already been made, pursuant to 40 CFR 93.104(e). See, 73 FR... ceiling for the regional transportation network. The MVEB is provided in Table 1: Table 1--Baton Rouge...

  16. 75 FR 9893 - Adequacy Determination for the Denver Metro Area and North Front Range 8-Hour Ozone Attainment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ... Implementation Plan (SIP) on June 18, 2009, by James B. Martin, Director, Colorado Department of Public Health...) which was promulgated August 15, 1997 (see 62 FR 43780). We described our process for determining the adequacy of submitted SIP MVEBs in our July 1, 2004 Transportation Conformity Rule Amendments (see 69...

  17. 75 FR 51960 - Proposed Rule To Implement the 1997 8-Hour Ozone National Ambient Air Quality Standard: New...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-24

    ... (69 FR 23951, April 30, 2004). The rule further provides that an area remains subject to these... National Association of Manufacturers; and (3) the American Petroleum Institute, American Chemistry Council.... \\4\\ 70 FR 30592 (May 26, 2005). In the second reconsideration rulemaking, we proposed and...

  18. 75 FR 55977 - Adequacy Status of the Knoxville, TN 1997 8-Hour Ozone Maintenance Plan Motor Vehicle Emission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-15

    ... Additional Rule Changes'' (69 FR 40004). Please note that an adequacy review is separate from EPA's... made, pursuant to 40 CFR 93.104(e). See 73 FR 4419 (January 24, 2008). Authority: 42 U.S.C. 7401 et seq... Court of Appeals for the District of Columbia Circuit (DC Circuit) ruled that submitted SIPs cannot...

  19. 77 FR 73570 - Approval and Promulgation of Implementation Plans; New Jersey and New York Ozone Attainment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-11

    ... 8-hour ozone implementation rule, published on November 29, 2005 (70 FR 71612) (Phase 2 Rule... of the 2008 ozone NAAQS. \\2\\ See 73 FR 16436; March 27, 2008. For a detailed explanation of the... to address the requirements of the 1997 8-hour ozone standard: On July 17, 2008 (73 FR 41068),...

  20. Plasma total antioxidant status in horses after 8-hours of road transportation

    PubMed Central

    2013-01-01

    Background The aim of this study was to investigate the effects of 8-hour road transport on plasma total antioxidant status (PTAS) and general clinical appearance in horses. Findings The study was conducted on a group of 60 horses of different breeds aged from 4 to 10 years. Venous blood was collected and a clinical examination was performed immediately before loading horses onto trailers for an 8 hour transport (I), immediately after unloading them from the trailer (II), and after a subsequent 24 hour stall rest (III). The ferric-reducing ability of plasma (FRAP) was used to determine PTAS. The transportation significantly increased respiratory and heart rates. The average PTAS increased during the three subsequent samplings: I: 170 ± 77 (μmol/l) II: 204 ± 70 (μmol/l) III: 221 ± 74 (μmol/l). Conclusion Long-distance transport increased the PTAS horses, as well as respiratory and heart rates. PMID:23945316

  1. Modal Sequencing in an 8-hour GMRT Observation of Pulsar B1822-09

    NASA Astrophysics Data System (ADS)

    Latham, C.; Mitra, D.; Rankin, J.

    2012-12-01

    The research presented here examines an 8-hour observation of pulsar B1822-09, acquired with the Giant Metrewave Radio Telescope. B1822-09 is known to exhibit two stable emission modes, the B mode, where the precursor (PC) “turns on”, and the Q mode, which is defined by interpulse (IP) emission. These emission modes are like pulsar “personalities.” Our analyses have shown that the pulsar's two modes are not as “pure” as previously thought, in that PC emission is sometimes seen in the B mode, IP emission in Q-mode intervals and near transitions PS and IP emission can occur simultaneously. Further, in this long observation, the Q mode shows periodic modulation near 46.6±1.0 rotation periods that modulates both the main pulse IP. We find indications that this represents a P3 associated with a subbeam carousel, and that its circulation time is thrice this value. Moreover, we detected a B-mode modulation at 70±3 that appears to have an odd-even character—thus both cycles are commensurate at around 140 rotation periods.

  2. 40 CFR 52.2088 - Control strategy: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR 51.918), this determination suspends the reasonable further progress and attainment demonstration... ozone implementation rule (see 40 CFR 51.918), this determination suspends the reasonable further... Island serious ozone nonattainment area, and approves the contingency measures for purposes of...

  3. 40 CFR 52.2088 - Control strategy: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CFR 51.918), this determination suspends the reasonable further progress and attainment demonstration... ozone implementation rule (see 40 CFR 51.918), this determination suspends the reasonable further... Island serious ozone nonattainment area, and approves the contingency measures for purposes of...

  4. 40 CFR 52.2088 - Control strategy: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CFR 51.918), this determination suspends the reasonable further progress and attainment demonstration... ozone implementation rule (see 40 CFR 51.918), this determination suspends the reasonable further... Island serious ozone nonattainment area, and approves the contingency measures for purposes of...

  5. 40 CFR 52.2088 - Control strategy: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CFR 51.918), this determination suspends the reasonable further progress and attainment demonstration... ozone implementation rule (see 40 CFR 51.918), this determination suspends the reasonable further... Island serious ozone nonattainment area, and approves the contingency measures for purposes of...

  6. 40 CFR 52.930 - Control strategy: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control strategy: Ozone. 52.930 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Kentucky § 52.930 Control strategy: Ozone. (a) The VOC... nonattainment to attainment was approved on October 23, 2001. The motor vehicle emissions budgets for VOC...

  7. 40 CFR 52.426 - Control strategy plans for attainment and rate-of-progress: ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and rate-of-progress: ozone. 52.426 Section 52.426 Protection of Environment ENVIRONMENTAL PROTECTION... § 52.426 Control strategy plans for attainment and rate-of-progress: ozone. (a) EPA fully approves, as... Delaware portion of the Philadelphia-Wilmington-Trenton severe ozone nonattainment, namely Kent and...

  8. 40 CFR 52.136 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the State of Arizona on April 13, 1994 for the Maricopa County ozone nonattainment area from the NOX RACT...

  9. 40 CFR 52.235 - Control strategy for ozone: Oxides of nitrogen.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy for ozone: Oxides of... for ozone: Oxides of nitrogen. EPA is approving an exemption request submitted by the Monterey Bay Unified Air Pollution Control District on April 26, 1994 for the Monterey Bay ozone nonattainment...

  10. 40 CFR 52.426 - Control strategy plans for attainment and rate-of-progress: ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and rate-of-progress: ozone. 52.426 Section 52.426 Protection of Environment ENVIRONMENTAL PROTECTION... § 52.426 Control strategy plans for attainment and rate-of-progress: ozone. (a) EPA fully approves, as... Delaware portion of the Philadelphia-Wilmington-Trenton severe ozone nonattainment, namely Kent and...

  11. 76 FR 17373 - Approval and Promulgation of Implementation Plans; Nevada; Determination of Attainment for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-29

    ... nonattainment area has attained the 1997 8-hour ozone national ambient air quality standards (NAAQS). This... monitoring period. Preliminary air quality monitoring data available for 2010 are consistent with continued... Attainment for the Clark County 8-Hour Ozone Nonattainment Area AGENCY: Environmental Protection Agency...

  12. 77 FR 36404 - Approval and Promulgation of Air Quality Implementation Plans; Massachusetts; Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-19

    ... significant regulatory actions based on health or safety risks subject to Executive Order 13045 (62 FR 19885...; Determination of Attainment of the 1997 Ozone Standard for the Western Massachusetts Nonattainment Area AGENCY... Massachusetts) moderate 1997 8-hour ozone nonattainment area has attained the 1997 8-hour National Ambient...

  13. 77 FR 25363 - Approval and Promulgation of Implementation Plans and Designations of Areas for Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-30

    ... FR 23858), EPA published a final rule designating and classifying areas under the 8-hour ozone NAAQS... data, 2001-2003. Under EPA's implementation rule for the 1997 8-hour ozone standard (69 FR 23951, April... FR 23958). The St. Louis area was classified as a subpart 2, 8-hour ozone moderate nonattainment...

  14. 77 FR 5210 - Approval and Promulgation of Implementation Plans and Designations of Areas for Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-02

    ... background for this action? On July 18, 1997 (62 FR 38856), EPA promulgated an 8-hour ozone standard of 0.08... 1997 8-hour ozone standard (69 FR 23951, April 30, 2004), an area was classified under subpart 2 of the..., 8-hour ozone moderate nonattainment area by EPA on April 30, 2004 (69 FR 23858, 23898, and...

  15. 75 FR 10420 - Approval and Promulgation of Implementation Plans: 1-Hour Ozone Extreme Area Plan for San Joaquin...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-08

    ... of Proposed Actions On July 14, 2009 at 74 FR 33933, EPA proposed to approve in part and disapprove...-hour ozone standard). 69 FR 20550 (April 15, 2004). Although we established a new 8-hour ozone standard...\\ See 62 FR 38856 (July 18, 1997). In 2008 we lowered the 8- hour ozone standard to 0.075 ppm. See 73...

  16. 77 FR 3720 - Determination of Failure To Attain the One-Hour Ozone Standard by 2007, Determination of Current...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-25

    ..., EPA reviewed ozone monitoring air quality data from the States, in accordance with 40 CFR 50.9, 40 CFR... Implement the 8-Hour Ozone National Ambient Air Quality Standard--Phase 1,'' referred to as the Phase 1 Rule... period). \\2\\ Final Rule to Implement the 8-Hour Ozone National Ambient Air Quality Standard--Phase 1,...

  17. 40 CFR 51.913 - How do the section 182(f) NOX exemption provisions apply for the 8-hour NAAQS?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 2 2011-07-01 2011-07-01 false How do the section 182(f) NOX exemption... How do the section 182(f) NOX exemption provisions apply for the 8-hour NAAQS? (a) A person may petition the Administrator for an exemption from NOX obligations under section 182(f) for any...

  18. 75 FR 2091 - Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-14

    ... part of the nonattainment area during the 1991 1-hour designations. On February 16, 1995 (60 FR 3352... a ``moderate'' 1997 8- hour ozone nonattainment area (see, 69 FR 23857, April 30, 2004). On July 15... nonattainment area was reclassified as ``moderate'' (73 FR 16547). EPA set a deadline of March 1, 2009 for...

  19. Approval and promulgation of Michigan State Implementation Plan (SIP). carbon monoxide and ozone

    SciTech Connect

    Not Available

    1980-06-02

    These two US Environmental Protection Agency notices approve the revised Michigan SIP for ozone control strategy for the Flint, Lansing, Grand Rapids, and other rural nonattainment areas; ozone, carbon monoxide control, and vehicle inspection/maintenance programs fr the Detroit urban areas; and transportation control plans for all these areas. These final rules are effective as of 5/23/80.

  20. 40 CFR 52.2428 - Control Strategy: Carbon monoxide and ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ozone National Ambient Air Quality Standard (NAAQS). This determination, in accordance with 40 CFR 51... PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Virginia § 52.2428... Progress Plan for the Virginia portion of the Metropolitan Washington, D.C. ozone nonattainment...

  1. 40 CFR 52.2428 - Control Strategy: Carbon monoxide and ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ozone National Ambient Air Quality Standard (NAAQS). This determination, in accordance with 40 CFR 51... PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Virginia § 52.2428... Progress Plan for the Virginia portion of the Metropolitan Washington, D.C. ozone nonattainment...

  2. 40 CFR 52.2125 - Control strategy: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR 51.918, suspends the... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Control strategy: Ozone. 52.2125... strategy: Ozone. (a) Determination of attaining data. EPA has determined, as of November 15, 2011, the...

  3. 40 CFR 52.1779 - Control strategy: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR 51.918, suspends the... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Control strategy: Ozone. 52.1779... strategy: Ozone. (a) Determination of attaining data. EPA has determined, as of November 15, 2011, the...

  4. 40 CFR 52.2125 - Control strategy: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR 51.918, suspends the... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Control strategy: Ozone. 52.2125... strategy: Ozone. (a) Determination of attaining data. EPA has determined, as of November 15, 2011, the...

  5. 40 CFR 52.2125 - Control strategy: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR 51.918, suspends the... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Control strategy: Ozone. 52.2125... strategy: Ozone. (a) Determination of attaining data. EPA has determined, as of November 15, 2011, the...

  6. 40 CFR 52.1779 - Control strategy: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR 51.918, suspends the... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Control strategy: Ozone. 52.1779... strategy: Ozone. (a) Determination of attaining data. EPA has determined, as of November 15, 2011, the...

  7. 40 CFR 52.1779 - Control strategy: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR 51.918, suspends the... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Control strategy: Ozone. 52.1779... strategy: Ozone. (a) Determination of attaining data. EPA has determined, as of November 15, 2011, the...

  8. Cerebral blood flow determination within the first 8 hours of cerebral infarction using stable xenon-enhanced computed tomography

    SciTech Connect

    Hughes, R.L.; Yonas, H.; Gur, D.; Latchaw, R.

    1989-06-01

    Cerebral blood flow mapping with stable xenon-enhanced computed tomography (Xe/CT) was performed in conjunction with conventional computed tomography (CT) within the first 8 hours after the onset of symptoms in seven patients with cerebral infarction. Six patients had hemispheric infarctions, and one had a progressive brainstem infarction. Three patients with very low (less than 10 ml/100 g/min) blood flow in an anatomic area appropriate for the neurologic deficit had no clinical improvement by the time of discharge from the hospital; follow-up CT scans of these three patients confirmed infarction in the area of very low blood flow. Three patients with moderate blood flow reductions (15-45 ml/100 g/min) in the appropriate anatomic area had significant clinical improvement from their initial deficits and had normal follow-up CT scans. One patient studied 8 hours after stroke had increased blood flow (hyperemia) in the appropriate anatomic area and made no clinical recovery.

  9. 77 FR 64036 - Determination of Attainment of the 1-Hour Ozone National Ambient Air Quality Standards in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-18

    ...EPA is determining that the Sacramento Metro 1-hour ozone nonattainment area (Sacramento Metro Area) has attained the revoked National Ambient Air Quality Standard (1-hour ozone NAAQS or standard), and to exclude certain 2008 data caused by wildfire exceptional events. These air quality determinations were proposed in conjunction with a proposed determination to terminate the State of......

  10. 78 FR 32131 - Revision to the Washington State Implementation Plan; Tacoma-Pierce County Nonattainment Area

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... nonattainment area is included in the EPA's proposal for this action (78 FR 4804, January 23, 2013). As... nonattainment area met the 2006 PM 2.5 NAAQS for the 2009-2011 monitoring period (77 FR 53772). Since the...'' subject to review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735,...

  11. 40 CFR 52.1118 - Approval of bubbles in nonattainment areas lacking approved demonstrations: State assurances.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Approval of bubbles in nonattainment... IMPLEMENTATION PLANS (CONTINUED) Maryland § 52.1118 Approval of bubbles in nonattainment areas lacking approved demonstrations: State assurances. In order to secure approval of a bubble control strategy for the...

  12. 40 CFR 52.1118 - Approval of bubbles in nonattainment areas lacking approved demonstrations: State assurances.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Approval of bubbles in nonattainment... IMPLEMENTATION PLANS (CONTINUED) Maryland § 52.1118 Approval of bubbles in nonattainment areas lacking approved demonstrations: State assurances. In order to secure approval of a bubble control strategy for the...

  13. 40 CFR 52.1118 - Approval of bubbles in nonattainment areas lacking approved demonstrations: State assurances.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Approval of bubbles in nonattainment... IMPLEMENTATION PLANS (CONTINUED) Maryland § 52.1118 Approval of bubbles in nonattainment areas lacking approved demonstrations: State assurances. In order to secure approval of a bubble control strategy for the...

  14. 40 CFR 52.1118 - Approval of bubbles in nonattainment areas lacking approved demonstrations: State assurances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Approval of bubbles in nonattainment... IMPLEMENTATION PLANS (CONTINUED) Maryland § 52.1118 Approval of bubbles in nonattainment areas lacking approved demonstrations: State assurances. In order to secure approval of a bubble control strategy for the...

  15. 40 CFR 51.910 - What requirements for reasonable further progress (RFP) under sections 172(c)(2) and 182 apply...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-hour ozone NAAQS? 51.910 Section 51.910 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.910 What... nonattainment for the 8-hour ozone NAAQS? (a) What are the general requirements for RFP for an area...

  16. 78 FR 63934 - Approval of Air Quality Implementation Plans; California; El Dorado County Air Quality Management...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ... area for the 1997 8-hour ozone NAAQS. 40 CFR 81.305; 69 FR 23858 at 23887 (April 30, 2004) (final rule... nonattainment for the 1997 8-hour ozone NAAQs); 75 FR 24409 (May 5, 2010) (final rule reclassifying Sacramento...-hour ozone NAAQS (70 FR 71612, November 29, 2005) discusses RACT requirements. It states in part...

  17. 40 CFR 51.910 - What requirements for reasonable further progress (RFP) under sections 172(c)(2) and 182 apply...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.910 What...-hour ozone NAAQS? 51.910 Section 51.910 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nonattainment for the 8-hour ozone NAAQS? (a) What are the general requirements for RFP for an area...

  18. 40 CFR 51.910 - What requirements for reasonable further progress (RFP) under sections 172(c)(2) and 182 apply...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.910 What...-hour ozone NAAQS? 51.910 Section 51.910 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nonattainment for the 8-hour ozone NAAQS? (a) What are the general requirements for RFP for an area...

  19. 40 CFR 51.910 - What requirements for reasonable further progress (RFP) under sections 172(c)(2) and 182 apply...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Provisions for Implementation of 8-hour Ozone National Ambient Air Quality Standard § 51.910 What...-hour ozone NAAQS? 51.910 Section 51.910 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... nonattainment for the 8-hour ozone NAAQS? (a) What are the general requirements for RFP for an area...

  20. 40 CFR 52.582 - Control strategy: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... satisfies 40 CFR 58.20(f) which requires the State to provide for the establishment and maintenance of... area has attaining data for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control strategy: Ozone. 52.582...

  1. 40 CFR 52.582 - Control strategy: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... satisfies 40 CFR 58.20(f) which requires the State to provide for the establishment and maintenance of... area has attaining data for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control strategy: Ozone. 52.582...

  2. 40 CFR 52.582 - Control strategy: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... satisfies 40 CFR 58.20(f) which requires the State to provide for the establishment and maintenance of... area has attaining data for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control strategy: Ozone. 52.582...

  3. 40 CFR 52.582 - Control strategy: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., into the Georgia State Implementation Plan. This submittal satisfies 40 CFR 58.20(f) which requires the... data for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR 51.918, suspends... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control strategy: Ozone. 52.582...

  4. 40 CFR 52.2052 - Motor vehicle emissions budgets for Pennsylvania ozone areas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Pennsylvania ozone areas. 52.2052 Section 52.2052 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...) Pennsylvania § 52.2052 Motor vehicle emissions budgets for Pennsylvania ozone areas. (a) As of December 26... nitrogen oxides (NOX) and volatile organic compounds (VOCs) for the Lancaster 1997 8-Hour Ozone...

  5. 40 CFR 52.2043 - Control strategy for maintenance plans: ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...: ozone. 52.2043 Section 52.2043 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Control strategy for maintenance plans: ozone. (a) As of December 26, 2013, EPA approves the following... (VOCs) for the Lancaster 1997 8-Hour Ozone Maintenance Area submitted by the Secretary of...

  6. 40 CFR 50.15 - National primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... air quality standards for ozone. 50.15 Section 50.15 Protection of Environment ENVIRONMENTAL....15 National primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts...

  7. 40 CFR 50.15 - National primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air quality standards for ozone. 50.15 Section 50.15 Protection of Environment ENVIRONMENTAL....15 National primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts...

  8. 40 CFR 50.15 - National primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air quality standards for ozone. 50.15 Section 50.15 Protection of Environment ENVIRONMENTAL....15 National primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts...

  9. 40 CFR 50.15 - National primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air quality standards for ozone. 50.15 Section 50.15 Protection of Environment ENVIRONMENTAL....15 National primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts...

  10. 40 CFR 50.15 - National primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air quality standards for ozone. 50.15 Section 50.15 Protection of Environment ENVIRONMENTAL....15 National primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts...

  11. 40 CFR 52.1989 - Interstate Transport for the 1997 8-hour ozone NAAQS and 1997 PM2.5 NAAQS.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Act section 169A and 40 CFR 51.308(e) regarding Best Available Retrofit Technology and the requirements of 40 CFR 51.308(d)(2) and (d)(4)(v) regarding the calculation of baseline and natural conditions..., Kalmiopsis Wilderness Area, Mountain Lakes Wilderness Area, Gearhart Mountain Wilderness Area, Crater...

  12. 40 CFR 52.1989 - Interstate Transport for the 1997 8-hour ozone NAAQS and 1997 PM2.5 NAAQS.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Act section 169A and 40 CFR 51.308(e) regarding Best Available Retrofit Technology and the requirements of 40 CFR 51.308(d)(2) and (d)(4)(v) regarding the calculation of baseline and natural conditions..., Kalmiopsis Wilderness Area, Mountain Lakes Wilderness Area, Gearhart Mountain Wilderness Area, Crater...

  13. 40 CFR 52.1989 - Interstate Transport for the 1997 8-hour ozone NAAQS and 1997 PM2.5 NAAQS.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Act section 169A and 40 CFR 51.308(e) regarding Best Available Retrofit Technology and the requirements of 40 CFR 51.308(d)(2) and (d)(4)(v) regarding the calculation of baseline and natural conditions..., Kalmiopsis Wilderness Area, Mountain Lakes Wilderness Area, Gearhart Mountain Wilderness Area, Crater...

  14. 75 FR 26898 - Determination of Attainment for PM-10; Fort Hall PM-10 Nonattainment Area, Idaho

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-13

    ...EPA is proposing under the Clean Air Act (CAA) to determine that the Fort Hall PM-10 nonattainment area on the Fort Hall Indian Reservation in Idaho has attained the National Ambient Air Quality Standards (NAAQS) for particulate matter with an aerodynamic diameter of less than or equal to 10 microns (PM-10). EPA's proposed finding that the Fort Hall PM-10 nonattainment area has attained the......

  15. 77 FR 30087 - Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ...This rule establishes initial air quality designations for most areas in the United States, including areas of Indian country, for the 2008 primary and secondary national ambient air quality standards (NAAQS) for ozone. The designations for several counties in Illinois, Indiana, and Wisconsin that the EPA is considering for inclusion in the Chicago nonattainment area will be designated in a......

  16. 78 FR 27161 - Approval and Promulgation of Air Quality Implementation Plans; Connecticut; Ozone Attainment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-09

    ... respiratory disease, such as asthma. On April 30, 2004 (69 FR 23858), EPA finalized its attainment... moderate ozone nonattainment area. See 40 CFR 81.307. Also, on April 30, 2004 (69 FR 23951), EPA... on November 29, 2005 (70 FR 71612) (Phase 2 Rule) specifies that states must submit...

  17. 78 FR 33726 - Approval and Promulgation of Implementation Plans; Kentucky: Kentucky Portion of Cincinnati...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... rule (58 FR 62188). Under section 176(c) of the CAA, transportation plans, transportation improvement... designated as nonattainment for the 1997 8-hour ozone NAAQS effective June 15, 2004 (69 FR 23858).\\1... attainment for the 1997 8-hour ozone NAAQS on August 5, 2010, (75 FR 47218). As part of this...

  18. 75 FR 53219 - Approval and Promulgation of Air Quality Implementation Plans; Connecticut; Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ... significant regulatory actions based on health or safety risks subject to Executive Order 13045 (62 FR 19885...; Determination of Attainment of the 1997 Ozone Standard for the Greater Connecticut Area AGENCY: Environmental... moderate 1997 8-hour ozone nonattainment area has attained the 1997 8-hour National Ambient Air...

  19. 40 CFR 52.147 - Interstate transport.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... deterioration of air quality, only) for the 1997 8-hour ozone and 1997 PM2.5 NAAQS. (b) Disapproval. The SIPs... the 1997 8-hour ozone and 1997 PM2.5 NAAQS. (c) Approval. The SIP submitted on October 14, 2009 meets... nonattainment or interfere with maintenance of the NAAQS in any other state) for the 2006 PM2.5 NAAQS....

  20. 77 FR 66921 - Approval and Promulgation of Air Quality Implementation Plans; New Hampshire; Reasonably...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-08

    ... being in nonattainment of the 1997 8-hour ozone NAAQS (69 FR 23858). In New Hampshire, the Boston... made further revisions to the ozone NAAQS setting the 8-hour standard at 0.075 ppm (73 FR 16436, March..., 2006, EPA issued four new CTGs which states were required to address by October 5, 2007 (71 FR...

  1. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS...)(3)(iii) of this section. 40 CFR part 81, subpart C identifies the boundaries of areas and the area... obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 may be modified by the State only...

  2. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS...)(3)(iii) of this section. 40 CFR part 81, subpart C identifies the boundaries of areas and the area... obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 may be modified by the State only...

  3. Issues on urban ozone: Natural hydrocarbons, urbanization and ozone control strategies

    SciTech Connect

    Cardelino, C.A.

    1991-01-01

    Using the Atlanta metropolitan area as a case study, the author has examined the effects of urbanization and its associated heat island on urban ozone concentrations. As cities grow, two important effects take place: the amount of trees is reduced and there is an increase in ambient temperature due to the urban heat island effect. As the temperature increases, more ozone is photochemically produced, more anthropogenic hydrocarbons are released into the atmosphere, and more biogenic hydrocarbons are emitted from the remaining trees. This increase in hydrocarbons helps produce even more ozone. Numerical simulations using conditions of a typical summertime day in Atlanta suggest that these processes are able to offset the reductions in anthropogenic hydrocarbon emissions caused by emission controls. To study ozone control strategies, the author has developed a photochemical model that utilizes ozone and ozone precursors observations as input data, and is therefore independent of the highly uncertain processes of emission inventories and transport. In contrast with the operation of the current emission-based models, the observation-based model (OBM) is relatively easy to implement and very fast to operate. Using numerical simulations of different meteorological and chemical conditions in Atlanta, he has shown that the ozone sensitivities obtained with the observation-based model, are in very good agreement with similar ozone sensitivities derived using an emission-based model that includes transport. He also illustrated the potential utility of the OBM by applying it to the ozone non-attainment problem in Baton Rouge, Louisiana.

  4. 40 CFR 80.27 - Controls and prohibitions on gasoline volatility.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., Sacramento, San Joaquin, Shasta, Stanislaus, Sutter, Tehama, Tulare, Tuolumne, Yolo, Yuba, and Nevada. South... designated volatility nonattainment areas and their exact boundaries are described in 40 CFR part 81, or such... encompasses the Denver-Boulder-Greeley-Ft. Collins-Loveland, CO, 8-hour ozone nonattainment area (see 40...

  5. 76 FR 28661 - Interim Final Determination To Defer Sanctions, Sacramento Metro 1-Hour Ozone Nonattainment Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ...,'' ``us'' and ``our'' refer to EPA. I. Background On January 5, 2010 (75 FR 232), we published a finding....S.C. 553(d)(1)). Note that today's action has no impact on the January 5, 2010 (75 FR 232) findings... Executive Order 12866 (58 FR 51735, October 4, 1993), this action is not a ``significant regulatory...

  6. 78 FR 42018 - Determination of Attainment for the Sacramento Nonattainment Area for the 2006 Fine Particle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-15

    ..., 2012 (77 FR 65346), EPA proposed to determine that the Sacramento nonattainment area in California has... period. The monitoring network in the area is operated by the California Air Resources Board (CARB) and...\\ See, e.g., 75 FR 6571 (February 10, 2010) (Baton Rouge, Louisiana area); 71 FR 6352 (February 8,...

  7. 75 FR 63139 - Approval and Promulgation of Implementation Plans-Maricopa County (Phoenix) PM-10 Nonattainment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-14

    .... SUMMARY: On September 9, 2010 (75 FR 54806), EPA published a proposed rule proposing to approve in part.../actions . SUPPLEMENTARY INFORMATION: On September 9, 2010 (75 FR 54806), EPA published a proposed rule... Nonattainment Area; Serious Area Plan for Attainment of the 24-Hour PM-10 Standard; Clean Air Act Section...

  8. 78 FR 7340 - Approval and Promulgation of Implementation Plans; Idaho: Sandpoint PM10 Nonattainment Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ... for PM 10 (52 FR 24634). The EPA established a 24-hour standard of 150 g/m\\3\\ and an annual standard... retained the 24-hour PM 10 standard but revoked the annual PM 10 standard (71 FR 61144, effective December... nonattainment area due to measured violations of the 24-hour PM 10 standard (52 FR 29383). The notice...

  9. 78 FR 887 - Determination of Attainment for the Nogales Nonattainment Area for the 2006 Fine Particle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-07

    ... AGENCY 40 CFR Part 52 Determination of Attainment for the Nogales Nonattainment Area for the 2006 Fine.... Statutory and Executive Order Reviews I. Summary of Proposed Action On October 30, 2012 (77 FR 65656), EPA... FR 51735, October 4, 1993); Does not impose an information collection burden under the provisions...

  10. 77 FR 65656 - Determination of Attainment for the Nogales Nonattainment Area for the 2006 Fine Particle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-30

    ... AGENCY 40 CFR Part 52 Determination of Attainment for the Nogales Nonattainment Area for the 2006 Fine... secondary\\1\\ annual and 24-hour standards for PM 2.5 (62 FR 38652). The annual standard was set at 15.0... air pollutant in the ambient air. See CAA section 109(b). On October 17, 2006 (71 FR 61144),...

  11. 75 FR 28227 - Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NSR): Aggregation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-20

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 51 and 52 RIN 2060-AP80 Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NSR): Aggregation Correction Proposed Rule document 2010-11578...

  12. 75 FR 97 - Approval and Promulgation of Air Quality Implementation Plan: Kentucky; Approval Section 110(a)(1...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-04

    ... nonattainment for the 1-hour ozone NAAQS effective November 6, 1991 (56 FR 56694) because the Area did not meet... Kentucky's request to redesignate the Paducah Area (60 FR 7124) to attainment for the 1-hour ozone standard. On April 30, 2004, EPA designated areas for the 1997 8-hour ozone NAAQS (69 FR 23858), and...

  13. 76 FR 43598 - Approval and Promulgation of Air Quality Plans: State of Missouri

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-21

    ... ozone NAAQS in this ozone nonattainment areas. See 76 FR 33647 (June 9, 2011) for more information about... obligations under the 1-hour ozone standard. See, 65 FR 31482, May 18, 2000. Today's action does not affect... determination on June 9, 2011 (76 FR 33647) that the St. Louis (MO-IL) metropolitan 1997 8-hour...

  14. 40 CFR 52.523 - Control strategy: Ozone

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...)(2)(J). A FIP is currently in place and approved for Florida at 40 CFR 52.37 for these requirements... 52.523 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED.... EPA is disapproving portions of Florida's infrastructure SIP for the 1997 8-hour ozone NAAQS...

  15. 40 CFR 52.523 - Control strategy: Ozone

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...)(2)(J). A FIP is currently in place and approved for Florida at 40 CFR 52.37 for these requirements... 52.523 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED.... EPA is disapproving portions of Florida's infrastructure SIP for the 1997 8-hour ozone NAAQS...

  16. 77 FR 3417 - Approval and Promulgation of Air Quality Implementation Plans; Massachusetts; Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-24

    ... December 31, 2003. See 66 FR 666 (January 3, 2001). ] On July 18, 1997 (62 FR 38856), EPA promulgated a new... rule. See 69 FR 23858. EPA designated Western Massachusetts as nonattainment for the 1997 8-hour ozone..., 2004, EPA issued a final rule (69 FR 23951) entitled ``Final Rule To Implement the 8-Hour...

  17. 75 FR 62026 - Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-07

    ...On July 14, 2010, the State of Tennessee, through the Tennessee Department of Environment and Conservation (TDEC), Air Pollution Control Division, submitted a request to redesignate the Knoxville 8- hour ozone nonattainment area to attainment for the 1997 8-hour National Ambient Air Quality Standards (NAAQS); and to approve a State Implementation Plan (SIP) revision containing a maintenance......

  18. Colorado Front Range Surface Ozone Analysis

    NASA Astrophysics Data System (ADS)

    McClure-Begley, A.; Petropavlovskikh, I. V.; Oltmans, S. J.; Kofler, J.; Petron, G.; Cothrel, H.

    2014-12-01

    The Colorado Front Range is a unique geographical region for air quality studies, including research of surface level ozone. Not only does surface ozone play a critical role in regulating the oxidation capacity of the atmosphere, but is a primary contributor to local smog and leads to public health complications and altered ecosystem functioning. The high frequency of sunny days, increasing population and pollution, and Mountain/Valley air dynamics of this region provide atmospheric conditions suitable for production and accumulation of ozone at the surface. This region of Colorado is currently in an ozone non-attainment status due to an assortment of contributing factors. Precursor emissions from pollution, wild-fires, and gas and oil production; along with stratosphere-troposphere exchange, can all result in high ozone episodes over the Colorado Front Range. To understand the dynamics of ozone accumulation in this region, Thermo-Scientific ozone monitors have been continuously sampling ozone from 4 different altitudes since the early 2000s. Analysis of ozone data in relation to Nitrogen Oxides (NOx), Methane (CH4), Carbon Monoxide (CO), wind-conditions and back-trajectory air mass origins help to address local ozone precursor emissions and resulting high ozone episodes. Increased ozone episodes are scrutinized with regards to dominant wind direction to determine main precursor emission sources. Analysis of this data reveals a strong influence of precursor emissions from the North-East wind sector, with roughly 50% of ozone exceedances originating from winds prevailing from this direction. Further, correlation with methane is enhanced when prevailing winds are from the North-East; indicative of influence from natural gas processes and feedlot activity. Similar analysis is completed for the North-West wind sector exceedances, with strong correlation to carbon monoxide; likely related to emissions from biomass burning events and forest fires. In depth analysis of

  19. Ozone trends in California`s South Coast Air Basin, 1976--1996

    SciTech Connect

    Cohanim, S.; Cassmassi, J.; Bassett, M.

    1998-12-31

    The South Coast Air Basin (Basin) of Southern California exhibits the worst air quality in the nation, as measured by the annual number of days exceeding the 1-hour National Ambient Air Quality Standard (NAAQS) for ozone. Hourly pollutant concentration data collected by the South Coast Air Quality Management District`s air monitoring network are compared to the existing 1-hour and new 8-hour federal ozone ambient air quality standards to depict ozone trends and compliance in the Basin. Results of trend analyses for the different areas of the Basin are presented for the 1-hour and 8-hour standards, and the relative stringency of the existing and new federal standards is examined. Based on an analysis of the effect of the recently adopted federal standard on ozone compliance in the Basin, ozone concentrations exceed the new federal 8-hour standard level more often than the existing 1-hour standard in most locations. However, examination of the trends in design values for the 1-hour and 8-hour ozone standards suggests that for most locations in the Basin the new standard probably should not be significantly more difficult to attain than the existing standard. The weather-adjusted ozone trend analysis in the Basin confirms the fact that the downtrends in ozone concentrations and number of days exceeding standards are real and independent of annual variation in weather. An analysis of weekday/weekend differences in exceedances for the existing 1-hour and new 8-hour ozone standards show a higher number of days exceeding both standards on weekends for most locations in the Basin, with differences being more evident in the 1990s than in the late 1970s and 1980s

  20. Methodology to estimate nonroad equipment populations by nonattainment areas. Final report

    SciTech Connect

    Not Available

    1991-09-30

    The Clean Air Act Amendments of 1990 require that EPA conduct a study to determine the contribution of nonroad equipment to the emission inventories of selected nonattainment areas. The contribution is determined by the population of nonroad equipment in a given area, the average load factor at which the equipment's engine is used, the average annual hours of use of the equipment, the horsepower of the engine, and the emission factor attributable to the engine. Since a nonattainment area is a conglomeration of counties within a state, or across states, it is necessary to estimate the county level equipment populations. Engine sales data or equipment population data, however, are not available at the county level, but only at the national and state level. Therefore, a methodology that distributes equipment populations from these levels of aggregation to the county level must be developed. The report presents EEA's methodology to estimate equipment populations for the 24 nonattainment areas included in EPA's study. The report also presents national data on load factors, annual usage, and horsepower.

  1. Spatio-temporal modeling for real-time ozone forecasting

    PubMed Central

    Paci, Lucia; Gelfand, Alan E.; Holland, David M.

    2013-01-01

    The accurate assessment of exposure to ambient ozone concentrations is important for informing the public and pollution monitoring agencies about ozone levels that may lead to adverse health effects. High-resolution air quality information can offer significant health benefits by leading to improved environmental decisions. A practical challenge facing the U.S. Environmental Protection Agency (USEPA) is to provide real-time forecasting of current 8-hour average ozone exposure over the entire conterminous United States. Such real-time forecasting is now provided as spatial forecast maps of current 8-hour average ozone defined as the average of the previous four hours, current hour, and predictions for the next three hours. Current 8-hour average patterns are updated hourly throughout the day on the EPA-AIRNow web site. The contribution here is to show how we can substantially improve upon current real-time forecasting systems. To enable such forecasting, we introduce a downscaler fusion model based on first differences of real-time monitoring data and numerical model output. The model has a flexible coefficient structure and uses an efficient computational strategy to fit model parameters. Our hybrid computational strategy blends continuous background updated model fitting with real-time predictions. Model validation analyses show that we are achieving very accurate and precise ozone forecasts. PMID:24010052

  2. A Transport Analysis of In Situ Airborne Ozone Measurements from the 2011 DISCOVER-AQ Campaign

    NASA Astrophysics Data System (ADS)

    Arkinson, H. L.; Brent, L. C.; He, H.; Loughner, C.; Stehr, J. W.; Weinheimer, A. J.; Dickerson, R. R.

    2013-12-01

    Baltimore and Washington are currently designated as nonattainment areas with respect to the 2008 EPA National Ambient Air Quality Standard (NAAQS) for 8-hour Ozone (O3). Tropospheric O3 is the dominant component of summertime photochemical smog, and at high levels, has deleterious effects on human health, ecosystems, and materials. The University of Maryland (UMD) Regional Atmospheric Measurement Modeling and Prediction Program (RAMMPP) strives to improve understanding of air quality in the Mid-Atlantic States and to elucidate contributions of pollutants such as O3 from regional transport versus local sources through a combination of modeling and in situ measurements. The NASA Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) project investigates the connection between column measurements and surface conditions to explore the potential of remote sensing observations in diagnosing air quality at ground level where pollutants can affect human health. During the 2011 DISCOVER-AQ field campaign, in situ airborne measurements of trace gases and aerosols were performed along the Interstate 95 corridor between Baltimore and Washington from the NASA P3B aircraft. To augment this data and provide regional context, measurements of trace gases and aerosols were also performed by the RAMMPP Cessna 402B aircraft over nearby airports in Maryland and Virginia. This work presents an analysis of O3 measurements made by the Ultraviolet (UV) Photometric Ambient O3 Analyzer on the RAMMPP Cessna 402B and by the NCAR 4-Channel Chemiluminescence instrument on the NASA P3B. In this analysis, spatial and temporal patterns of O3 data are examined within the context of forward and backward trajectories calculated from 12-km North American Mesoscale (NAM) meteorological data using the NOAA Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) Model and from a high resolution Weather Research and

  3. 40 CFR 52.1576 - Determinations of attainment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Jersey § 52.1576 Determinations..., EPA determined that Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE 8-hour ozone moderate... the New York-Northern New Jersey-Long Island (NY-NJ-CT) one-hour ozone nonattainment area did not...

  4. 75 FR 27514 - Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

    ... protective than the previous 1-hour ozone standard (62 FR 38855).\\1\\ The EPA published the 1997 8-hour ozone designations and classifications on April 30, 2004 (69 FR 23858). The BPA area was designated nonattainment and... standard. See 61 FR 16483. As a result of its reclassification to serious, the State was required,...

  5. 75 FR 31288 - Approval and Promulgation of Air Quality Implementation Plans; Rhode Island; Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-03

    ... ozone nonattainment area has attained the 1997 8-hour National Ambient Air Quality Standard (NAAQS) for...-hour National Ambient Air Quality Standard (NAAQS) for ozone. This determination is based upon complete... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; Rhode...

  6. 77 FR 14691 - Approval and Promulgation of Air Quality Implementation Plans; Rhode Island; Reasonably Available...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-13

    ... being in nonattainment of the 1997 8-hour ozone NAAQS (69 FR 23858). The entire State of Rhode Island... Standard--Phase 2 (the Phase 2 Rule) (70 FR 71612; November 29, 2005). As noted in the EPA's Phase 2 ozone... 16, 2006. (See 40 CFR 51.916(b)(2).) On March 24, 2008 (73 FR 15416), EPA issued a finding of...

  7. Assessment of ambient ozone air quality and evidence of transport effects in eastern Kern County, California

    SciTech Connect

    Beutelman, H.P.; Hallman, P.K.; Franz, J.A.

    1998-12-31

    Edwards AFB is located in the Mojave desert of southern California. The bulk of the base is located in the eastern part of Kern County, and is classified as serious non-attainment for ozone. However, geographically the eastern part of Kern County is separated form the western part of the county by some of the tallest mountains in the continental US. It has long been suspected, but not well quantified, that the air quality in eastern Kern County is impacted by transport of ozone from the San Joaquin area (as well as possible transport from the Los Angeles Basin area). Because of the significance of the ozone non-attainment designation with regards to the Department of Defense Base Realignment and Closure process, improved assessment of ambient ozone air quality and possible routes of transport in eastern Kern County was required. This was accomplished by; installing and operating an ambient air quality monitoring station at Edwards AFB; and comparing at least one year of data (ozone, NO{sub x} and meteorological) from the Edwards AFB station with similar data from the California Air Resources Board operated stations in the upwind locations (along possible transport routes) of Edison (western Kern County), Mojave (eastern Kern County) and Lancaster (northern Los Angeles County). Empirical analysis of this and other data indicate that; (1) compared to western Kern County, eastern Kern County is in a significantly different and isolated air basin; (2) the peak ambient ozone levels in eastern Kern County are substantially lower than in western Kern County; (3) peak ambient ozone levels in eastern Kern County occur late afternoon/early evening and are indicative of transport of ozone and (4) direct transport of ozone from the San Joaquin and/or South Coast area does occur (given proper conditions). This paper will address the elements of this study and its conclusions.

  8. Spatial analysis of ozone in Atlanta: Regulatory and epidemiologic implications

    SciTech Connect

    Butler, A.J.; Mulholland, J.A.; Wilkinson, J.G.; Russell, A.G.; Tolbert, P.E.

    1998-12-31

    Relationships between ambient levels of selected air pollutants and pediatric asthma exacerbation in Atlanta were studied retrospectively. As a part of this study, spatial distributions of ambient ozone concentrations in the twenty-county Atlanta metropolitan area during the summers of 1993, 1994 and 1995 were estimated and assessed. A universal kriging procedure was used for spatial interpolation of aerometric monitoring station data. In this paper, the spatial distributions of ozone are described, and regulatory and epidemiologic implications are discussed. For the study period, the Atlanta ozone nonattainment area based on the one-hour, exceedance-based standard of 0.12 ppm is estimated to expand from 56 percent of the Atlanta MSA by area and 71 percent by population to 88 percent by area and 96 percent by population under the new eight-hour, concentration-based standard of 0.08 ppm. Regarding asthma exacerbation, a 4 percent increase in pediatric asthma emergency room presentation rate per 20 ppb increase in ambient ozone concentration was observed (p-value = 0.001). Ambient ozone level represents a general indicator of air quality due to its correlation with other pollutants. The use of spatially-resolved ozone estimates in the epidemiologic analysis demonstrates the need to control confounding by demographic covariates.

  9. 78 FR 55225 - Determination of Attainment for the Chico Nonattainment Area for the 2006 Fine Particle Standard...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-10

    ... Fine Particle Implementation Rule'' (72 FR 20586, April 25, 2007) and the ``Implementation of the New... AGENCY 40 CFR Part 52 Determination of Attainment for the Chico Nonattainment Area for the 2006 Fine... Executive Order Reviews I. Summary of EPA's Proposed Action On October 30, 2012 (77 FR 65651), EPA...

  10. 40 CFR 51.1006 - Redesignation to nonattainment following initial designations for the PM2.5 NAAQS.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... following initial designations for the PM2.5 NAAQS. 51.1006 Section 51.1006 Protection of Environment... OF IMPLEMENTATION PLANS Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1006 Redesignation to nonattainment following initial designations for the PM2.5 NAAQS. Any...

  11. 40 CFR 51.1006 - Redesignation to nonattainment following initial designations for the PM2.5 NAAQS.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... following initial designations for the PM2.5 NAAQS. 51.1006 Section 51.1006 Protection of Environment... OF IMPLEMENTATION PLANS Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1006 Redesignation to nonattainment following initial designations for the PM2.5 NAAQS. Any...

  12. 40 CFR 51.1006 - Redesignation to nonattainment following initial designations for the PM2.5 NAAQS.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... following initial designations for the PM2.5 NAAQS. 51.1006 Section 51.1006 Protection of Environment... OF IMPLEMENTATION PLANS Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1006 Redesignation to nonattainment following initial designations for the PM2.5 NAAQS. Any...

  13. 40 CFR 51.1006 - Redesignation to nonattainment following initial designations for the PM2.5 NAAQS.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... following initial designations for the PM2.5 NAAQS. 51.1006 Section 51.1006 Protection of Environment... OF IMPLEMENTATION PLANS Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1006 Redesignation to nonattainment following initial designations for the PM2.5 NAAQS. Any...

  14. 40 CFR 51.1006 - Redesignation to nonattainment following initial designations for the PM2.5 NAAQS.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... following initial designations for the PM2.5 NAAQS. 51.1006 Section 51.1006 Protection of Environment... OF IMPLEMENTATION PLANS Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1006 Redesignation to nonattainment following initial designations for the PM2.5 NAAQS. Any...

  15. 75 FR 2935 - Extension of Deadline for Promulgating Designations for the 2008 Ozone National Ambient Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-19

    ..., 2008, EPA promulgated revised 8-hour primary and secondary ozone NAAQS (73 FR 16436; March 27, 2008... promulgation of a new or revised national ambient air quality standard for any pollutant under section 109, the... a national ambient air quality standard, the Administrator shall promulgate the designations of...

  16. 78 FR 21302 - Approval and Promulgation of Implementation Plans; New York State Ozone Implementation Plan Revision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-10

    ... outdoors, and individuals with a pre-existing respiratory disease, such as asthma. On April 30, 2004 (69 FR... a requirement to submit a demonstration of attainment. EPA notes that on December 7, 2009 (74 FR..., 2008 (73 FR 15672) EPA determined that Jefferson County attained the 8-hour ozone standard. On June...

  17. Improved Space-Time Forecasting of next Day Ozone Concentrations in the Eastern U.S.

    EPA Science Inventory

    There is an urgent need to provide accurate air quality information and forecasts to the general public and environmental health decision-makers. This paper develops a hierarchical space-time model for daily 8-hour maximum ozone concentration (O3) data covering much of the easter...

  18. Impact of Large-scale Circulation Patterns on Surface Ozone Variability in Houston-Galveston-Brazoria

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Jia, B.; Xie, Y.

    2015-12-01

    The Bermuda High (BH) is a key driver of large-scale circulation patterns for Southeastern Texas and other Gulf coast states in summer, with the expected influence on surface ozone through its modulation of marine air inflow with lower ozone background from the Gulf of Mexico. We develop a statistical relationship through multiple linear regression (MLR) to quantify the impact of the BH variations on surface ozone variability during the ozone season in the Houston-Galveston-Brazoria (HGB) area, a major ozone nonattainment region on the Gulf Coast. We find that the variability in BH location, represented by a longitude index of the BH west edge (BH-Lon) in the MLR, explains 50-60% of the year-to-year variability in monthly mean ozone over HGB for Jun and July during 1998-2013, and the corresponding figure for Aug and Sep is 20%. Additional 30%-40% of the ozone variability for Aug and Sep can be explained by the variability in BH strength, represented by two BH intensity indices (BHI) in the MLR, but its contribution is only 5% for June and not significant for July. Including a maximum Through stepwise regression based on Akaike Information Criterion (AIC), the MLR model captures 58~72% of monthly ozone variability during Jun-Sep with a cross-validation R2 of 0.5. This observation-derived statistical relationship will be valuable to constrain model simulations of ozone variability attributable to large-scale circulation patterns.

  19. Microporous carbon filters as catalysts for ozone decomposition

    SciTech Connect

    Whinnery, L.; Coutts, D.; Adams, R.; Shen, C.; Quintana, C.; Showalter, S.

    1995-02-01

    Ozone, an allotrope of oxygen, present in the upper atmosphere (ozonosphere) plays a critical role in radiative balance. However, ozone is a toxic gas with a pungent odor when present in the troposphere and is considered a health hazard. The Occupational Safety and Health Administration (OSHA) has established a maximum permissible exposure limit (PEL) of 0.1 ppM in an 8 hour period. There are many sources of exposure to ozone in the workplace. Ozone is generated by high voltage discharge wires found in laser printers and photocopiers. Other common uses for ozone include waste water treatment, medical and dental instrument sterilization, drinking water purification, industrial oxidation processes, bleaching, and as a bactericide in swimming pools. Carbon filters are often used to minimize worker exposure to ozone. When designing a filter to decompose unwanted ozone, there are three requirements for most commercial applications. The first requirement is that production costs of the filter be minimal. Many applications require large quantities of filters and may have to be changed out often. The relatively low PEL also requires the filters to have a very high ozone decomposition efficiency. Finally, current applications tend to use small, low power fans to move air through the filters. Low back pressure is required to prevent over heating and prevent buildup of the toxic and potentially explosive ozone. In this paper, we will discuss two porous carbon filters that satisfy all of these requirements.

  20. 78 FR 72036 - Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-02

    ...EPA is taking final action to redesignate the portion of North Carolina that is within the bi-state Charlotte-Gastonia-Rock Hill, North Carolina-South Carolina 8-hour ozone nonattainment area (hereafter referred to as the ``Area,'' ``North Carolina portion of the bi-state Charlotte Area,'' ``North Carolina portion of the Area,'' or ``Metrolina nonattainment area'') to attainment for the 1997......

  1. New ozone standard in the U.S.A. applied to Mexico City metropolitan air quality

    SciTech Connect

    Bravo A, H. Sosa E, R.; Sanchez A, P.; Jaimes P, M.

    1998-12-31

    The air quality of the Mexico City Metropolitan Zone (MCMZ) is recognized as one of the worst air pollution problems in the world. At the present, ozone is the most critical atmospheric pollutant in the area. According to the air quality data of the monitoring station at the University of Mexico, the ozone problem started in 1986. Mexican Ozone Air Quality Standard (MOAQS) specifies that a concentration of 0.11 ppm must not be exceeded more than one hour a day, one day a year in the term of three years. The Official Air Quality Data (RAMA) from 19 monitoring stations in the MCMZ coincides with the University station`s data, presenting the same atmospheric pollution problem. In the most critical sites the MOAQS is exceeded more than 1,300 hours in a year. Now, the Environmental Protection Agency of the United States (EPA) is working to establish the new ozone standard. EPA is setting the standard at 0.08 ppm on an average of 8 hours, considering the 3 year average of the annual 4th highest daily maximum 8 hour ozone concentration. The purpose of this paper is to present the tendency and comparison between two standards (1 hour and 8 hours) of the ozone concentrations in the MCMZ, since 1986 to 1996. Although Mexico does not yet have the 8 hour standard for ozone, it is very important to analyze the existing air quality data with this new standard. In this way the aim is to protect the health of more than 20 million inhabitants in the MCMZ.

  2. Polar ozone

    NASA Technical Reports Server (NTRS)

    Solomon, S.; Grose, W. L.; Jones, R. L.; Mccormick, M. P.; Molina, Mario J.; Oneill, A.; Poole, L. R.; Shine, K. P.; Plumb, R. A.; Pope, V.

    1990-01-01

    The observation and interpretation of a large, unexpected ozone depletion over Antarctica has changed the international scientific view of stratospheric chemistry. The observations which show the veracity, seasonal nature, and vertical structure of the Antarctic ozone hole are presented. Evidence for Arctic and midlatitude ozone loss is also discussed. The chemical theory for Antarctic ozone depletion centers around the occurrence of polar stratospheric clouds (PSCs) in Antarctic winter and spring; the climatology and radiative properties of these clouds are presented. Lab studies of the physical properties of PSCs and the chemical processes that subsequently influence ozone depletion are discussed. Observations and interpretation of the chemical composition of the Antarctic stratosphere are described. It is shown that the observed, greatly enhanced abundances of chlorine monoxide in the lower stratosphere are sufficient to explain much if not all of the ozone decrease. The dynamic meteorology of both polar regions is given, interannual and interhemispheric variations in dynamical processes are outlined, and their likely roles in ozone loss are discussed.

  3. Ozone decomposition

    PubMed Central

    Batakliev, Todor; Georgiev, Vladimir; Anachkov, Metody; Rakovsky, Slavcho

    2014-01-01

    Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers). Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates. PMID:26109880

  4. Ozone decomposition.

    PubMed

    Batakliev, Todor; Georgiev, Vladimir; Anachkov, Metody; Rakovsky, Slavcho; Zaikov, Gennadi E

    2014-06-01

    Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers). Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates. PMID:26109880

  5. Ozone variability

    NASA Astrophysics Data System (ADS)

    Duetsch, H. U.

    1983-09-01

    The annual and long-term variations in the atmospheric ozone layer were examined on the basis of 55 yr of data taken at Aroya, Switzerland and 25 yr of data gathered by the global ozone network. Attention was given to annual and biennial variations, which showed that the midlatitude peak concentration was affected by a quasi-biennial variation of the tropical stratospheric circulation. Smaller scale circulation patterns were dominant in the lower stratosphere, although an observed negative trend of the total ozone was equally distributed between the troposphere and 24 km altitude. The global ozone increase detected in the 1960s was possible due to general circulation alterations, but may also have been influenced by injection of NO(x) into the atmosphere during atomic bomb testing.

  6. Ozone, Tropospheric

    NASA Technical Reports Server (NTRS)

    Fishman, Jack

    1995-01-01

    In the early part of the 20th century, ground-based and balloon-borne measurements discovered that most of atmosphere's ozone is located in the stratosphere with highest concentrations located between 15 and 30 km (9,3 and 18.6 miles). For a long time, it was believed that tropospheric ozone originated from the stratosphere and that most of it was destroyed by contact with the earth's surface. Ozone, O3, was known to be produced by the photo-dissociation of molecular oxygen, O2, a process that can only occur at wavelengths shorter than 242 nm. Because such short-wave-length radiation is present only in the stratosphere, no tropospheric ozone production is possible by this mechanism. In the 1940s, however, it became obvious that production of ozone was also taking place in the troposphere. The overall reaction mechanism was eventually identified by Arie Haagen-Smit of the California Institute of Technology, in highly polluted southern California. The copious emissions from the numerous cars driven there as a result of the mass migration to Los Angeles after World War 2 created the new unpleasant phenomenon of photochemical smog, the primary component of which is ozone. These high levels of ozone were injuring vegetable crops, causing women's nylons to run, and generating increasing respiratory and eye-irritation problems for the populace. Our knowledge of tropospheric ozone increased dramatically in the early 1950s as monitoring stations and search centers were established throughout southern California to see what could be done to combat this threat to human health and the environment.

  7. Effects of ozone and peroxyacetyl nitrate on polar lipids and Fatty acids in leaves of morning glory and kidney bean.

    PubMed

    Nouchi, I; Toyama, S

    1988-07-01

    To compare the effects of ozone and peroxyacetyl nitrate (PAN) on leaf lipids, fatty acids and malondialdehyde (MDA), morning glory (Pharbitis nil Choisy cv Scarlet O'Hara) and kidney bean (Phaseolus vulgaris L. cv Gintebo) plants were exposed to either ozone (0.15 microliter per liter for 8 hours) or PAN (0.10 microliter per liter for up to 8 hours). Ozone increased phospholipids in morning glory and decreased in kidney bean at the initial stage (2-4 hours) of exposure, while it scarcely changed glycolipids, the unsaturated fatty acids, and MDA in both plants. A large reduction of glycolipids occurred 1 day after ozone exposure in both plants. PAN caused marked drops in phospholipids and glycolipids in kidney bean at relatively late stage (6-8 hours) of exposure, while it increased phosphatidic acid and decreased the unsaturated fatty acids, an increase which was accompanied by a large increase in MDA. These results suggest that ozone may not directly oxidize unsaturated fatty acids at the initial stage of exposure, but may alter polar lipid metabolism, particularly phospholipids. On the other hand, PAN may abruptly and considerably degrade phospholipids and glycolipids by peroxidation or hydrolysis at the late stage of exposure. The present study shows that ozone and PAN affect polar lipids in different manners. PMID:16666199

  8. Pulmonary Responses in Healthy Young Adults Exposed to Low Concentration of Ozone for 6.6 Hours with Mild Exercise

    EPA Science Inventory

    Rational: Recent studies have shown small but significant decreases in lung function following a prolonged exposure (6.6 hour) of healthy young adults to levels of ozone (0.08 ppm) near the current 8 hour standard. It is unclear, however, if such effects may be extended to concen...

  9. Regulatory ozone modeling: status, directions, and research needs.

    PubMed Central

    Georgopoulos, P G

    1995-01-01

    The Clean Air Act Amendments (CAAA) of 1990 have established selected comprehensive, three-dimensional, Photochemical Air Quality Simulation Models (PAQSMs) as the required regulatory tools for analyzing the urban and regional problem of high ambient ozone levels across the United States. These models are currently applied to study and establish strategies for meeting the National Ambient Air Quality Standard (NAAQS) for ozone in nonattainment areas; State Implementation Plans (SIPs) resulting from these efforts must be submitted to the U.S. Environmental Protection Agency (U.S. EPA) in November 1994. The following presentation provides an overview and discussion of the regulatory ozone modeling process and its implications. First, the PAQSM-based ozone attainment demonstration process is summarized in the framework of the 1994 SIPs. Then, following a brief overview of the representation of physical and chemical processes in PAQSMs, the essential attributes of standard modeling systems currently in regulatory use are presented in a nonmathematical, self-contained format, intended to provide a basic understanding of both model capabilities and limitations. The types of air quality, emission, and meteorological data needed for applying and evaluating PAQSMs are discussed, as well as the sources, availability, and limitations of existing databases. The issue of evaluating a model's performance in order to accept it as a tool for policy making is discussed, and various methodologies for implementing this objective are summarized. Selected interim results from diagnostic analyses, which are performed as a component of the regulatory ozone modeling process for the Philadelphia-New Jersey region, are also presented to provide some specific examples related to the general issues discussed in this work. Finally, research needs related to a) the evaluation and refinement of regulatory ozone modeling, b) the characterization of uncertainty in photochemical modeling, and c

  10. Improvement of MM5 Model Forecast by Ingesting Newly Archived Satellite Data and Estimation of Forest Fire Emissions Contribution to Ozone Peaks Using CMAQ Modeling System

    NASA Astrophysics Data System (ADS)

    Ghidey, Tesfamichael B.

    02 to simulate CMAQ over the Southern Sierra Nevada and the San Joaquin Valley (SJV) of central California. The results from this study show that wildfire and prescribed fires contribute increased O3 concentration downwind of the burn area during high actinic flux episodes. O3 concentration formed from the NEI02 averaged wildfires showed an increase of 16 ppb for the representative day of maximum 8-hour average O3. The prescribed fire events also contributed a maximum O3 of 31 ppb per hour downwind of the burn area. These results suggest that both wild and prescribed fires can potentially contribute to violations in both state and federal air quality standards (non-attainment limits), though for the examined cases exceedances did not occur. Air quality standard violation areas are classified as non-attainment zones by federal regulators, which can lead to punitive actions by federal agencies.

  11. Evaluation of microporous carbon filters as catalysts for ozone decomposition

    SciTech Connect

    Whinnery, L.; Coutts, D.; Shen, C.; Adams, R.; Quintana, C.; Showalter, S.

    1994-12-31

    Ozone is produced in small quantities in photocopiers and laser printers in the workplace and large quantities in industrial waste water treatment facilities. Carbon filters are commonly used to decompose this unwanted ozone. The three most important factors in producing a filter for this purpose are flow properties, efficiency, and cost. Most ozone decomposition applications require very low back-pressure at modest flow rates. The tradeoff between the number of pores and the size of the pores will be discussed. Typical unfiltered emissions in the workplace are approximately 1 ppm. The maximum permissible exposure limit, PEL, for worker exposure to ozone is 0.1 ppm over 8 hours. Several methods have been examined to increase the efficiency of ozone decomposition. Carbon surfaces were modified with catalysts, the surface activated, and the surface area was increased, in attempts to decompose ozone more effectively. Methods to reduce both the processing and raw material costs were investigated. Several sources of microporous carbon were investigated as ozone decomposition catalysts. Cheaper processing routes including macropore templating, faster drying and extracting methods were also studied.

  12. Synoptic and meteorological drivers of extreme ozone concentrations over Europe

    NASA Astrophysics Data System (ADS)

    Otero, Noelia Felipe; Sillmann, Jana; Schnell, Jordan L.; Rust, Henning W.; Butler, Tim

    2016-04-01

    The present work assesses the relationship between local and synoptic meteorological conditions and surface ozone concentration over Europe in spring and summer months, during the period 1998-2012 using a new interpolated data set of observed surface ozone concentrations over the European domain. Along with local meteorological conditions, the influence of large-scale atmospheric circulation on surface ozone is addressed through a set of airflow indices computed with a novel implementation of a grid-by-grid weather type classification across Europe. Drivers of surface ozone over the full distribution of maximum daily 8-hour average values are investigated, along with drivers of the extreme high percentiles and exceedances or air quality guideline thresholds. Three different regression techniques are applied: multiple linear regression to assess the drivers of maximum daily ozone, logistic regression to assess the probability of threshold exceedances and quantile regression to estimate the meteorological influence on extreme values, as represented by the 95th percentile. The relative importance of the input parameters (predictors) is assessed by a backward stepwise regression procedure that allows the identification of the most important predictors in each model. Spatial patterns of model performance exhibit distinct variations between regions. The inclusion of the ozone persistence is particularly relevant over Southern Europe. In general, the best model performance is found over Central Europe, where the maximum temperature plays an important role as a driver of maximum daily ozone as well as its extreme values, especially during warmer months.

  13. The Role of Galveston Bay Meteorology in Ozone Concentrations in Houston, Texas

    NASA Astrophysics Data System (ADS)

    Nielsen-Gammon, J. W.; Tobin, J.

    2007-12-01

    Galveston Bay is a body of water approximately 50 km by 30 km that opens into the Gulf of Mexico. The head of Galveston Bay is adjacent to the Houston Ship Channel, where large industrial emitters of ozone precursors are located. We consider the role of coastal circulations and mixing suppression over Galveston Bay in the location and magnitude of peak 8-h ozone values at monitors within the Houston-Galveston-Brazoria nonattainment area. Galveston Bay is found to have a salutary effect on ozone concentrations under most circumstances. Aside from boats and ships, Galveston Bay is free of ozone precursor emissions, and the onset of the sea breeze along Galveston Bay usually causes an immediate drop in ozone levels. The situation changes dramatically when the morning wind direction is from the northwest, allowing ozone precursors emitted during the night or early morning that are distributed in a shallow atmospheric layer to be carried over Galveston Bay. In morning and early afternoon, mixing is suppressed over Galveston Bay, and precursor concentrations remain high in the absence of ventilation. If winds are strong, high ozone concentrations are generally observed along the far shore of Galveston Bay. If winds are weak, a sea breeze will develop along Galveston Bay, and high levels of ozone will be carried back onshore in the vicinity of the Ship Channel. The coastal oscillation (a regular rotation of the wind vector driving by coastal heating contrasts near 30 N) can lead to wind reversals and high values of ozone by itself. We investigate peak ozone concentrations under a variety of wind conditions to infer whether the ozone concentrations are, on balance, higher due to the net effect of meteorological processes associated with Galveston Bay.

  14. 75 FR 39635 - Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-12

    ...EPA is approving Wisconsin's requests to redesignate the Manitowoc County and Door County, Wisconsin nonattainment areas to attainment for the 1997 8-hour ozone standard because the requests meet the statutory requirements for redesignation under the Clean Air Act (CAA). The Wisconsin Department of Natural Resources (WDNR) submitted these requests on September 11, 2009. These approvals involve......

  15. 76 FR 38334 - Approval and Promulgation of Air Quality Implementation Plans; District of Columbia, Maryland...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-30

    ... and the Reid Vapor Pressure (RVP) regulations promulgated June 11, 1990 (55 FR 23666). The FMVCP and..., 2004 (69 FR 23951), EPA finalized its attainment/ nonattainment designations for areas across the... 8-hour ozone implementation rule (Phase 1 rule), published on April 30, 2004 (69 FR 23951), an...

  16. 78 FR 55234 - Approval and Promulgation of Implementation Plans; Indiana; Volatile Organic Compound Emission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-10

    ...-Lake County, IL-IN, 1997 8-hour ozone nonattainment area. See 75 FR 8246. These rules included new rule..., adhesive and resin manufacturing, based on the Bay Area rules, on August 7, 2012 (77 FR 46961). The... either contain less than 1.67 pounds VOC per gallon or have a VOC composite partial vapor pressure...

  17. 76 FR 31245 - Approval and Promulgation of Implementation Plans; Extension of Attainment Date for the Charlotte...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-31

    ... Carolina 1997 8- Hour Ozone Moderate Nonattainment Area,'' 75 FR 46881 (August 4, 2010). The comment period... the requirements for such extensions. See EPA's August 4, 2010, proposed rulemaking at 75 FR 46881 for... issued a finding of failure to submit. See 74 FR 21550 (May 8, 2009). The submissions that both...

  18. 78 FR 33230 - Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ... California Air Resources Board (CARB) on December 28, 2012. \\1\\ On March 27, 2008 (73 FR 16436), EPA..., EPA designated San Diego County as nonattainment for the 2008 8-hour ozone standard (77 FR 30088... maintenance plan, which is part of this action. II. Background On March 25, 2013 (78 FR 17902), EPA issued...

  19. 78 FR 19599 - Approval and Promulgation of Implementation Plans; Texas; Reasonably Available Control Technology...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-02

    ...The EPA is finalizing its proposal to approve revisions to the Texas State Implementation Plan (SIP) for the Houston/Galveston/ Brazoria (HGB) 1997 8-Hour ozone nonattainment Area (Area). The HGB Area consists of Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery and Waller counties. Specifically, we are finalizing our proposed approval of portions of two revisions to the......

  20. 78 FR 27065 - Approval and Promulgation of Implementation Plans; North Carolina; Control Techniques Guidelines...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-09

    ... nonattainment area with respect to the 1997 8-hour ozone NAAQS.\\1\\ See 69 FR ] 23858. The bi-state Charlotte... requirements for the South Carolina portion of the bi-state Charlotte Area on November 28, 2011. See 76 FR... rulemaking related to this final action at 78 FR 15895. \\3\\ The emission threshold is based on an...

  1. TROP OZONE

    EPA Science Inventory

    Activity Area (F01) The NRMRL tropospheric ozone research program is both coordinated with the research efforts of others and planned to achieve the most important unmet research needs that draw upon its unique expertise. For example, NRMRL emissions research in this area is co...

  2. Ozone studies in the Paso del Norte region

    NASA Astrophysics Data System (ADS)

    Becerra-Davila, Fernando

    The Paso del Norte region forms the largest contiguous bi-national conglomerate on the US-Mexico border. With a combined population of around 2 million inhabitants, the Paso del Norte region is isolated, more than 500 km away from the nearest urban area of comparable size, thus making it an ideal location for air quality studies of an isolated urban environment. The meteorological conditions leading to a high ozone episode in this region, such as the historical ozone episode of June 2006, are analyzed. It is well known that stagnation and minimal winds, high temperatures, and pressure ridges over the region are conducive to high ozone episodes. In addition, the planetary boundary height is studied to understand its impact on high ozone episodes. Several studies report that ground level ozone non-attainment regulations could be caused not only by local emissions, but also by atmospheric transport. In this work the atmospheric advection of pollutants into the region is analyzed using HYSPLIT backward trajectories. Furthermore, a novel backward trajectory clustering technique is implemented for the summer of 2006. The "ozone weekend effect" (OWE) is a phenomenon by which in some geographical regions ambient ozone concentrations tend to be higher on weekends than on weekdays, despite the lower emissions of ozone precursors during those days. The observed local OWE has never previously been studied in terms of the photolysis rates of four of the main ozone precursors. In this research a novel method that allows the calculation of actinic fluxes, photolysis frequencies and photolysis rates with a high degree of accuracy and reliability has been developed. This method utilizes a combination of the experimental data available for this region in conjunction with a radiative transfer model (TUV model). Three weekend-weekday cases during summers 2006, 2009 and 2010 are studied in this work. In this research, the photolysis impact on the local OWE is studied. The results

  3. The Antarctic Ozone Hole

    ERIC Educational Resources Information Center

    Jones, Anna E.

    2008-01-01

    Since the mid 1970s, the ozone layer over Antarctica has experienced massive destruction during every spring. In this article, we will consider the atmosphere, and what ozone and the ozone layer actually are. We explore the chemistry responsible for the ozone destruction, and learn about why conditions favour ozone destruction over Antarctica. For…

  4. Ozone and aircraft operations

    NASA Technical Reports Server (NTRS)

    Perkins, P. J.

    1981-01-01

    The cabin ozone problem is discussed. Cabin ozone in terms of health effects, the characteristics of ozone encounters by aircraft, a brief history of studies to define the problem, corrective actions taken, and possible future courses of action are examined. It is suggested that such actions include avoiding high ozone concentrations by applying ozone forecasting in flight planning procedures.

  5. Earth's Endangered Ozone

    ERIC Educational Resources Information Center

    Panofsky, Hans A.

    1978-01-01

    Included are (1) a discussion of ozone chemistry; (2) the effects of nitrogen fertilizers, fluorocarbons, and high level aircraft on the ozone layer; and (3) the possible results of a decreasing ozone layer. (MR)

  6. Ozone crisis

    SciTech Connect

    Roan, S.

    1989-01-01

    The author presents an account of the depletion of the atmosphere's ozone layer since the discovery of the phenomenon 15 years ago. The book recounts the flight to ban chlorofluorocarbons (CFC's) and describes the science, the people, and the politics involved, up to the March 1988 international treaty restricting CFC production. It surveys the media's coverage, describes the struggle for remedies, and offers a prognosis for the future.

  7. High Resolution Space-Time Ozone Modeling for Assessing Trends

    PubMed Central

    Sahu, Sujit K.; Gelfand, Alan E.; Holland, David M.

    2008-01-01

    The assessment of air pollution regulatory programs designed to improve ground level ozone concentrations is a topic of considerable interest to environmental managers. To aid this assessment, it is necessary to model the space-time behavior of ozone for predicting summaries of ozone across spatial domains of interest and for the detection of long-term trends at monitoring sites. These trends, adjusted for the effects of meteorological variables, are needed for determining the effectiveness of pollution control programs in terms of their magnitude and uncertainties across space. This paper proposes a space-time model for daily 8-hour maximum ozone levels to provide input to regulatory activities: detection, evaluation, and analysis of spatial patterns of ozone summaries and temporal trends. The model is applied to analyzing data from the state of Ohio which has been chosen because it contains a mix of urban, suburban, and rural ozone monitoring sites in several large cities separated by large rural areas. The proposed space-time model is auto-regressive and incorporates the most important meteorological variables observed at a collection of ozone monitoring sites as well as at several weather stations where ozone levels have not been observed. This problem of misalignment of ozone and meteorological data is overcome by spatial modeling of the latter. In so doing we adopt an approach based on the successive daily increments in meteorological variables. With regard to modeling, the increment (or change-in-meteorology) process proves more attractive than working directly with the meteorology process, without sacrificing any desired inference. The full model is specified within a Bayesian framework and is fitted using MCMC techniques. Hence, full inference with regard to model unknowns is available as well as for predictions in time and space, evaluation of annual summaries and assessment of trends. PMID:19759840

  8. Response of macaque bronchiolar epithelium to ambient concentrations of ozone

    SciTech Connect

    Harkema, J.R.; Plopper, C.G.; Hyde, D.M.; St. George, J.A.; Wilson, D.W.; Dungworth, D.L. )

    1993-09-01

    Recently, we reported that exposure to ambient concentrations of ozone, near the U.S. National Ambient Air Quality Standard (0.12 ppm), induced significant nasal epithelial lesions in a non-human primate, the bonnet monkey. The present study defines the effects of ambient concentrations of ozone on the surface epithelium lining respiratory bronchioles and on the underlying bronchiolar interstitium in these same monkeys. Bonnet monkeys were exposed to filtered air or to 0.15 or 0.30 ppm ozone 8 hours/day for 6 or 90 days. At the end of exposures, monkeys were anesthetized and killed by exsanguination. Microdissected bronchiolar airways of infusion-fixed lungs were evaluated morphometrically by light microscopy and quantitatively by scanning and transmission electron microscopy for ozone-induced epithelial changes. Hyperplasia of nonciliated, cuboidal epithelial cells and intraluminal accumulation of macrophages characterized ozone-induced lesions in respiratory bronchioles. There were no significant differences in epithelial thickness or cell numbers among ozone-exposed groups. Ozone-exposed epithelium was composed of 80% cuboidal and 20% squamous cells compared with 40% cuboidal and 60% squamous cells in filtered air controls. In addition, the arithmetic mean thickness of the surface epithelium, a measure of tissue mass per unit area of basal lamina, was significantly increased in all of the ozone-exposed groups. The number of cuboidal epithelial cells per surface area of basal lamina was increased above control values by 780% after 6 days exposure to 0.15 ppm, 777% after 90 days to 0.15 ppm, and 996% after 90 days exposure to 0.30 ppm. There was also a significant ozone-induced increase in the thickness of the bronchiolar interstitium that was due to an increase in both cellular and acellular components.

  9. Effects of ozone and peroxyacetyl nitrate on polar lipids and fatty acids in leaves of morning glory and kidney bean. [Pharbitis nil; Phaseolus vulgaris

    SciTech Connect

    Nouchi, Isamu; Toyama, Susumu Ochanomizu Univ., Tokyo )

    1988-07-01

    To compare the effects of ozone and peroxyacetyl nitrate (PAN) on leaf lipids, fatty acids and malondialdehyde (MDA), morning glory (Pharbitis nil Choisy cv Scarlet O'Hara) and kidney bean (Phaseolus vulgaris L. cv Gintebo) plants were exposed to either ozone (0.15 microliter per liter for 8 hours) or PAN (0.10 microliter per liter for up to 8 hours). Ozone increased phospholipids in morning glory and decreased in kidney bean at the initial stage (2-4 hours) of exposure, while it scarcely changed glycolipids, the unsaturated fatty acids, and MDA in both plants. A large reduction of glycolipids occurred 1 day after ozone exposure in both plants. PAN caused marked drops in phospholipids and glycolipids in kidney bean at relatively late stage (6-8 hours) of exposure, while it increased phosphatidic acid and decreased the unsaturated fatty acids, an increase which was accompanied by a large increase in MDA. These results suggest that ozone may not directly oxidize unsaturated fatty acids at the initial stage of exposure, but may alter polar lipid metabolism, particularly phospholipids. On the other hand, PAN may abruptly and considerably degrade phospholipids and glycolipids by peroxidation or hydrolysis at the late stage of exposure. The present study shows that ozone and PAN affect polar lipids in different manners.

  10. Impacts of interstate transport of pollutants on high ozone events over the Mid-Atlantic United States

    NASA Astrophysics Data System (ADS)

    Liao, Kuo-Jen; Hou, Xiangting; Baker, Debra Ratterman

    2014-02-01

    The impacts of interstate transport of anthropogenic nitrogen oxides (NOx) and volatile organic compound (VOC) emissions on peak ozone formation in four nonattainment areas (i.e., Baltimore, Philadelphia-Wilmington-Atlantic City, Pittsburgh-Beaver Valley and Washington, DC) in the Mid-Atlantic U.S. were quantified in this study. Regional air quality and sensitivities of ground-level ozone to emissions from four regions in the eastern U.S. were simulated for three summer months (June, July and August) in 2007 using the U.S. EPA's Community Multiscale Air Quality model with the decoupled direct method 3D. The emissions inventory used in this study was the 2007 Mid-Atlantic Regional Air Management Association Level 2 inventory, developed for State Implementation Plan screening modeling for the Ozone Transport Commission region. The modeling results show that responses of peak ozone levels at specific locations to emissions from EGU (i.e., electric generating unit) and non-EGU sources could be different. Therefore, emissions from EGU and non-EGU sources should be considered as two different control categories when developing regional air pollution mitigation strategies. Based on the emission inventories used in this study, reductions in anthropogenic NOx emissions (including those from EGU and non-EGU sources) from the Great Lake region as well as northeastern and southeastern U.S. would be effective for decreasing area-mean peak ozone concentrations during the summer of 2007 in the Mid-Atlantic ozone air quality nonattainment areas. The results also show that reductions in anthropogenic VOC emissions from the northeastern U.S. would also be effective for decreasing area-mean peak ozone concentrations over the Mid-Atlantic U.S. In some cases, reductions in anthropogenic NOx emissions from the Great Lake and northeastern U.S. could slightly increase area-mean peak ozone concentrations at some ozone monitors in the Pittsburgh-Beaver Valley and Washington, DC areas

  11. Ozone Precursor Trends in Colorado and Their Relevance to Oil and Gas Development

    NASA Astrophysics Data System (ADS)

    Pierce, G. E.; Frazier, A. C.

    2015-12-01

    Oil and gas development has occurred in Colorado for over 150 years. With the increasing use of horizontal drilling and hydraulic fracturing, development of shale oil resources has increased significantly during the past ten years. One of the areas is the Denver-Julesburg (D-J) Basin in northeast Colorado, where there are now over 20,000 active wells. The North Front Range area of Colorado, including Denver, is a non-attainment area for ozone, where emissions from oil and gas development in the D-J Basin are a major concern. If a lower ozone standard is promulgated by EPA, other areas of Colorado will likely be designated as non-attainment as well. Colorado has instituted a number of regulations on the oil and gas industry over the past decade to help reduce emissions. The Denver metropolitan area has also grown significantly over the past decades to a population of over 2.6 million, which adds an urban component to the mix of ozone precursor emissions. Ambient monitoring of ozone precursors, including non-methane organic compounds and carbonyls, has been performed at a number of locations in the North Front Range area of Colorado over the past 12 years. Two of these sites have been in continuous operation since 2012; one site is located in the core of the city of Denver, while the other is located in the center of the oil and gas development area and has recorded high levels of ethane. Additionally, air monitoring sites operating on the western slope of Colorado that includes the Piceance Basin have data as far back as 2004. We present trends from the ozone precursor monitoring conducted in Colorado, and discuss how these precursors may contribute to ozone formation, particularly those related to oil and gas development. These data are valuable for emissions inventory work and model validation related to upcoming State Implementation Plans for ozone. The data will also be used in association with the 2014 Front Range Air Pollution and Photochemistry Experiment

  12. Comparative Effects of Gamma Irradiation and Ozone Treatment on Hygienic Quality of Korean Red Ginseng Powder

    NASA Astrophysics Data System (ADS)

    Byun, Myung-Woo; Yook, Hong-Sun; Kang, Il-Jun; Chung, Cha-Kwon; Kwon, Joong-Ho; Choi, Kang-Ju

    1998-06-01

    For the purpose of improving hygienic quality of Korean red ginseng powder, the comparative effects of gamma irradiation and ozone treatment on the microbial and physicochemical properties were investigated. Gamma irradiation at 7.5 kGy resulted in sterilization of total aerobic bacteria, molds and coliforms below detective levels, while ozone treatment for 8 hours up to 18 ppm did not sufficiently eliminate the microorganisms of the red ginseng powder. Physicochemical properties including compositions of the red ginseng saponin (ginsenosides) and fatty acids, pH and hydrogen doanting activity were not significantly changed by gamma irradiation, whereas, ozone treatment caused significant changes in fatty acid compositions, TBA value, pH, acidity and hydrogen donating activity. The results from this study led us to conclude that gamma irradiation was more effective than ozone treatment both for the improvement of hygienic quality and for the maintenance of physicochemical quality of red ginseng powder.

  13. An analysis of the impacts of global climate and emissions changes on regional tropospheric ozone

    NASA Technical Reports Server (NTRS)

    John, Kuruvilla; Crist, Kevin C.; Carmichael, Gregory R.

    1994-01-01

    Many of the synergistic impacts resulting from future changes in emissions as well as changes in ambient temperature, moisture, and UV flux have not been quantified. A three-dimensional regional-scale photo-chemical model (STEM-2) is used in this study to evaluate these perturbations to trace gas cycles over the eastern half of the United States of America. The model was successfully used to simulate a regional-scale ozone episode (base case - June 1984) and four perturbations scenarios - viz., perturbed emissions, temperature, water vapor column, and incoming UV flux cases, and a future scenario (for the year 2034). The impact of these perturbation scenarios on the distribution of ozone and other major pollutants such as SO2 and sulfates were analyzed in detail. The spatial distribution and the concentration of ozone at the surface increased by about 5-15 percent for most cases except for the perturbed water vapor case. The regional scale surface ozone concentration distribution for the year 2034 (future scenario) showed an increase of non-attainment areas. The rural areas of Pennsylvania, West Virginia, and Georgia showed the largest change in the surface ozone field for the futuristic scenario when compared to the base case.

  14. Ozone Hole Over Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These images from the Total Ozone Mapping Spectrometer (TOMS) show the progressive depletion of ozone over Antarctica from 1979 to 1999. This 'ozone hole' has extended to cover an area as large as 10.5 million square miles in September 1998. The previous record of 10.0 million square miles was set in 1996. The Antarctic ozone hole develops each year between late August and early October. Regions with higher levels of ozone are shown in red. NASA and NOAA instruments have been measuring Antarctic ozone levels since the early 1970s. Large regions of depleted ozone began to develop over Antarctica in the early 1980s. Ozone holes of substantial size and depth are likely to continue to form during the next few years, scientists hope to see a reduction in ozone loss as levels of ozone-destroying CFCs (chlorofluorocarbons) are gradually reduced. Credit: Images by Greg Shirah, NASA Goddard Space Flight Center Scientific Visualization Studio

  15. A study of interferences in ambient ozone monitors

    SciTech Connect

    Kleindienst, T.E.; McIver, C.D.; Ollison, W.M.

    1997-12-31

    Recently proposed EPA revisions to the ozone ambient air quality standards change allowable ozone levels from 120 ppbv (1-hour average) to 70-90 ppbv (8-hour average). Accordingly, the relative importance of potential interferences in currently deployed ethylene-chemiluminescence and ultraviolet (UV) absorption monitors may be increased. UV absorption monitors predominate US monitoring networks and operate in a dual channel mode, requiring a scrubber to selectively remove ozone from other UV absorbing species. However, these scrubbers may also remove aromatic species with UV absorption coefficients at 254 run comparable to ozone that could constitute potential interferants. The interference potential for only a few of these compounds has been determined. Additional representative organic precursor species likely to be present under polluted conditions (e.g., C{sub 8}-C{sub 9} aromatic hydrocarbons and their nitroaromatic and phenolic derivatives) have been tested as UV interferants in this study. The removal and reentrainment of aromatic pollutants on ozone scrubbers used in UV monitors is highly dependent on the relative humidity in the system. Raising the temperature of the scrubber does not improve its interferant transmission under dry conditions and increases the retention of potential interferants under humid conditions. Reduced sulfur compounds such as CS{sub 2} do not appear to be interferants for the chemiluminescence monitor.

  16. Long-Term Exposure to Ozone and Life Expectancy in the United States, 2002 to 2008.

    PubMed

    Li, Chaoyang; Balluz, Lina S; Vaidyanathan, Ambarish; Wen, Xiao-Jun; Hao, Yongping; Qualters, Judith R

    2016-02-01

    Long-term exposure to ground-level ozone is associated with increased risk of morbidity and mortality. The association remains uncertain between long-term exposure to ozone and life expectancy. We assessed the associations between seasonal mean daily 8-hour maximum (8-hr max) ozone concentrations measured during the ozone monitoring seasons and life expectancy at birth in 3109 counties of the conterminous U.S. during 2002 to 2008. We used latent class growth analysis to identify latent classes of counties that had distinct mean levels and rates of change in ozone concentrations over the 7-year period and used linear regression analysis to determine differences in life expectancy by ozone levels. We identified 3 classes of counties with distinct seasonal mean daily 8-hr max ozone concentrations and rates of change. When compared with the counties with the lowest ozone concentrations, the counties with the highest ozone concentrations had 1.7- and 1.4-year lower mean life expectancy in males and females (both P < 0.0001), respectively. The associations remained statistically significant after controlling for potential confounding effects of seasonal mean PM2.5 concentrations and other selected environmental, demographic, socio-economic, and health-related factors (both P < 0.0001). A 5 ppb higher ozone concentration was associated with 0.25 year lower life expectancy in males (95% CI: -0.30 to -0.19) and 0.21 year in females (95% CI: -0.25 to -0.17). We identified 3 classes of counties with distinct mean levels and rates of change in ozone concentrations. Our findings suggest that long-term exposure to a higher ozone concentration may be associated with a lower life expectancy. PMID:26886595

  17. Long-Term Exposure to Ozone and Life Expectancy in the United States, 2002 to 2008

    PubMed Central

    Li, Chaoyang; Balluz, Lina S.; Vaidyanathan, Ambarish; Wen, Xiao-Jun; Hao, Yongping; Qualters, Judith R.

    2016-01-01

    Abstract Long-term exposure to ground-level ozone is associated with increased risk of morbidity and mortality. The association remains uncertain between long-term exposure to ozone and life expectancy. We assessed the associations between seasonal mean daily 8-hour maximum (8-hr max) ozone concentrations measured during the ozone monitoring seasons and life expectancy at birth in 3109 counties of the conterminous U.S. during 2002 to 2008. We used latent class growth analysis to identify latent classes of counties that had distinct mean levels and rates of change in ozone concentrations over the 7-year period and used linear regression analysis to determine differences in life expectancy by ozone levels. We identified 3 classes of counties with distinct seasonal mean daily 8-hr max ozone concentrations and rates of change. When compared with the counties with the lowest ozone concentrations, the counties with the highest ozone concentrations had 1.7- and 1.4-year lower mean life expectancy in males and females (both P < 0.0001), respectively. The associations remained statistically significant after controlling for potential confounding effects of seasonal mean PM2.5 concentrations and other selected environmental, demographic, socio-economic, and health-related factors (both P < 0.0001). A 5 ppb higher ozone concentration was associated with 0.25 year lower life expectancy in males (95% CI: −0.30 to −0.19) and 0.21 year in females (95% CI: −0.25 to −0.17). We identified 3 classes of counties with distinct mean levels and rates of change in ozone concentrations. Our findings suggest that long-term exposure to a higher ozone concentration may be associated with a lower life expectancy. PMID:26886595

  18. CMAQ predictions of tropospheric ozone in the U.S. southwest: influence of lateral boundary and synoptic conditions.

    PubMed

    Shi, Chune; Fernando, H J S; Hyde, Peter

    2012-02-01

    Phoenix, Arizona, has been an ozone nonattainment area for the past several years and it remains so. Mitigation strategies call for improved modeling methodologies as well as understanding of ozone formation and destruction mechanisms during seasons of high ozone events. To this end, the efficacy of lateral boundary conditions (LBCs) based on satellite measurements (adjusted-LBCs) was investigated, vis-à-vis the default-LBCs, for improving the predictions of Models-3/CMAQ photochemical air quality modeling system. The model evaluations were conducted using hourly ground-level ozone and NO(2) concentrations as well as tropospheric NO(2) columns and ozone concentrations in the middle to upper troposphere, with the 'design' periods being June and July of 2006. Both included high ozone episodes, but the June (pre-monsoon) period was characterized by local thermal circulation whereas the July (monsoon) period by synoptic influence. Overall, improved simulations were noted for adjusted-LBC runs for ozone concentrations both at the ground-level and in the middle to upper troposphere, based on EPA-recommended model performance metrics. The probability of detection (POD) of ozone exceedances (>75ppb, 8-h averages) for the entire domain increased from 20.8% for the default-LBC run to 33.7% for the adjusted-LBC run. A process analysis of modeling results revealed that ozone within PBL during bulk of the pre-monsoon season is contributed by local photochemistry and vertical advection, while the contributions of horizontal and vertical advections are comparable in the monsoon season. The process analysis with adjusted-LBC runs confirms the contributions of vertical advection to episodic high ozone days, and hence elucidates the importance of improving predictability of upper levels with improved LBCs. PMID:22227303

  19. The Clean Air Act Amendments of 1990 and industry; Title I non-attainment areas

    SciTech Connect

    Saunders, G.L. ); Laznow, J. )

    1991-10-01

    The signing into law of the CAA Amendments of 1990 will bring sweeping changes affecting significantly the way industry is regulated. This paper reports that the Amendments address a wide range of issues, including non- attainment areas, toxic air pollutants, acid rain, operating permits and fees, and regulatory enforcement. Regulations to be promulgated under the Amendments will stand in stark contrast to those promulgated after CAA was last amended in 1977. Many of the issues addressed by the 1990 Amendments have accumulated for years, waiting for legislation consideration. Title I of the Amendments sets National Ambient Air Quality Standards (NAAQS) for several criteria pollutants. The standard for ozone is of greatest general interest for stationary sources, along with requirements for control of nitrogen oxides (NO{sub x}) and VOCs.

  20. Antarctic Ozone Hole, 2000

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Each spring the ozone layer over Antarctica nearly disappears, forming a 'hole' over the entire continent. The hole is created by the interaction of some man-made chemicals-freon, for example-with Antarctica's unique weather patterns and extremely cold temperatures. Ozone in the stratosphere absorbs ultraviolet radiation from the sun, thereby protecting living things. Since the ozone hole was discovered many of the chemicals that destroy ozone have been banned, but they will remain in the atmosphere for decades. In 2000, the ozone hole grew quicker than usual and exceptionally large. By the first week in September the hole was the largest ever-11.4 million square miles. The top image shows the average total column ozone values over Antarctica for September 2000. (Total column ozone is the amount of ozone from the ground to the top of the atmosphere. A relatively typical measurement of 300 Dobson Units is equivalent to a layer of ozone 0.12 inches thick on the Earth's surface. Levels below 220 Dobson Units are considered to be significant ozone depletion.) The record-breaking hole is likely the result of lower than average ozone levels during the Antarctic fall and winter, and exceptionally cold temperatures. In October, however (bottom image), the hole shrank dramatically, much more quickly than usual. By the end of October, the hole was only one-third of it's previous size. In a typical year, the ozone hole does not collapse until the end of November. NASA scientists were surprised by this early shrinking and speculate it is related to the region's weather. Global ozone levels are measured by the Total Ozone Mapping Spectrometer (TOMS). For more information about ozone, read the Earth Observatory's ozone fact sheet, view global ozone data and see these ozone images. Images by Greg Shirah, NASA GSFC Scientific Visualization Studio.

  1. Gridded global surface ozone metrics for atmospheric chemistry model evaluation

    NASA Astrophysics Data System (ADS)

    Sofen, E. D.; Bowdalo, D.; Evans, M. J.; Apadula, F.; Bonasoni, P.; Cupeiro, M.; Ellul, R.; Galbally, I. E.; Girgzdiene, R.; Luppo, S.; Mimouni, M.; Nahas, A. C.; Saliba, M.; Tørseth, K.

    2016-02-01

    The concentration of ozone at the Earth's surface is measured at many locations across the globe for the purposes of air quality monitoring and atmospheric chemistry research. We have brought together all publicly available surface ozone observations from online databases from the modern era to build a consistent data set for the evaluation of chemical transport and chemistry-climate (Earth System) models for projects such as the Chemistry-Climate Model Initiative and Aer-Chem-MIP. From a total data set of approximately 6600 sites and 500 million hourly observations from 1971-2015, approximately 2200 sites and 200 million hourly observations pass screening as high-quality sites in regionally representative locations that are appropriate for use in global model evaluation. There is generally good data volume since the start of air quality monitoring networks in 1990 through 2013. Ozone observations are biased heavily toward North America and Europe with sparse coverage over the rest of the globe. This data set is made available for the purposes of model evaluation as a set of gridded metrics intended to describe the distribution of ozone concentrations on monthly and annual timescales. Metrics include the moments of the distribution, percentiles, maximum daily 8-hour average (MDA8), sum of means over 35 ppb (daily maximum 8-h; SOMO35), accumulated ozone exposure above a threshold of 40 ppbv (AOT40), and metrics related to air quality regulatory thresholds. Gridded data sets are stored as netCDF-4 files and are available to download from the British Atmospheric Data Centre (doi: 10.5285/08fbe63d-fa6d-4a7a-b952-5932e3ab0452). We provide recommendations to the ozone measurement community regarding improving metadata reporting to simplify ongoing and future efforts in working with ozone data from disparate networks in a consistent manner.

  2. Analysis and Comparison of Raw and Weather-corrected July Mean Ozone, Satellite-derived Tropospheric NO2 and Ozone, and Indicator Ratios from Space for the Colorado Front Range

    NASA Astrophysics Data System (ADS)

    Reddy, P. J.; Tonnesen, G.

    2012-12-01

    In order to evaluate the efficacy of emissions control strategies for reduction of ground-level ozone concentrations, it is important to determine how ozone sensitivity to NOx and VOC varies in space and time across a region. The Denver Non-attainment Area for ozone has several monitoring sites that exceed the National Ambient Air Quality Standard for eight-hour ozone concentrations. Aside from emissions, weather is a major factor that affects year-to-year variations in surface ozone. For Colorado's Front Range region, it has been found that much of the year-to-year variance in the surface ozone concentration data can be explained by the effects of upper-level high pressure strength. Local July mean 500-millibar heights account for more than fifty percent of the year-to-year variation in July mean daily maximum eight-hour ozone concentrations for most sites. We compare tropospheric column ozone data from the NASA OMI/MLS with patterns of 500-millibar heights across the Western U.S. and surface ozone data. This comparison highlights the role of the Four Corners high in years with increased accumulation of local or regional background ozone. We also compare trends in weather-corrected ozone with mean tropospheric NO2 from the OMI and GOME 2 retrievals and explore statistical relationships between ground-level and satellite measurements for the period from 2005 through 2012. These analyses provide clues about the responses of ground-level ozone to meteorology and climate and the significant real-world changes in tropospheric NO2 that occurred during the period. Finally, we analyze ratios of satellite-derived formaldehyde to NO2 and compare these with the results of process analyses of VOC and NOx sensitivity from photochemical modeling of a specific ozone episode in July 2006. Taken together, this work can serve as a weight-of-evidence analysis for State Implementation Plan ozone model attainment demonstrations and help to constrain estimates of ozone responses to

  3. Ozone in the free atmosphere

    NASA Technical Reports Server (NTRS)

    Whitten, R. C. (Editor); Prasad, S. S. (Editor)

    1985-01-01

    The present book provides a summary of the state of scientific knowledge of stratospheric and free tropospheric ozone as it exists at the beginning of 1983. Ozone photochemistry in the stratosphere is discussed, taking into account fundamental molecular properties, the absorption spectrum of ozone, photodissociation, ozone formation and destruction in the upper atmosphere, the photochemistry of odd-hydrogen, the photochemistry of odd-nitrogen, the photochemistry of odd-chlorine, and photochemistry-temperature coupling. The observed distribution of atmospheric ozone and its variations are considered along with ozone transport, ozone in the troposphere, stratospheric ozone perturbations, and climatic and biological effects. Attention is given to the techniques of observing atmospheric ozone, horizontal-vertical ozone transport and conservative quantities, measurements of tropospheric ozone, the tropospheric ozone budget, ozone models, natural ozone variations, and anthropogenic ozone perturbations.

  4. Source contributions to seasonal vegetative exposure to ozone in the US

    NASA Astrophysics Data System (ADS)

    Lapina, K.; Henze, D. K.; Milford, J.; Huang, M.; Lin, M.; Pfister, G.; Emmons, L. K.; Fiore, A. M.; Boynard, A.; Carmichael, G. R.; Sandiford, V.; Herrick, J. D.; Dutton, S.; Smith, T.; Porter, E. M.

    2012-12-01

    Frequent exposure to high levels of ozone leads to vegetation damage and can result in substantial economic losses. A cumulative ozone exposure metric, W126, has been considered by the US EPA for use as a secondary ozone standard. Information on source regions contributing to the non-attainment of this standard is crucial for developing a successful strategy to mitigate the negative effects of ozone on vegetation. In this work we quantify W126 source contributions for the US regions exceeding selected levels of the W126 standard by applying several source attribution techniques, including "tagging", emissions perturbation and adjoint sensitivity analysis, to a suite of five global and regional chemical transport models. We estimate the W126 North American background (defined as the W126 levels in the absence of North American anthropogenic emissions) and separate source contributions by sector and country of origin. Our calculations are performed for two periods in 2008 and 2010 and are compared to the W126 observations from the Air Quality System and CASTNET. Given that the W126 metric is highly non-linear, we discuss the pros and cons of the applied source attribution methods and the applicability of the results.

  5. Ozone Trend Detectability

    NASA Technical Reports Server (NTRS)

    Campbell, J. W. (Editor)

    1981-01-01

    The detection of anthropogenic disturbances in the Earth's ozone layer was studied. Two topics were addressed: (1) the level at which a trend in total ozoning is detected by existing data sources; and (2) empirical evidence in the prediction of the depletion in total ozone. Error sources are identified. The predictability of climatological series, whether empirical models can be trusted, and how errors in the Dobson total ozone data impact trend detectability, are discussed.

  6. Ozone Layer Observations

    NASA Technical Reports Server (NTRS)

    McPeters, Richard; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    The US National Aeronautics and Space Administration (NASA) has been monitoring the ozone layer from space using optical remote sensing techniques since 1970. With concern over catalytic destruction of ozone (mid-1970s) and the development of the Antarctic ozone hole (mid-1980s), long term ozone monitoring has become the primary focus of NASA's series of ozone measuring instruments. A series of TOMS (Total Ozone Mapping Spectrometer) and SBUV (Solar Backscatter Ultraviolet) instruments has produced a nearly continuous record of global ozone from 1979 to the present. These instruments infer ozone by measuring sunlight backscattered from the atmosphere in the ultraviolet through differential absorption. These measurements have documented a 15 Dobson Unit drop in global average ozone since 1980, and the declines in ozone in the antarctic each October have been far more dramatic. Instruments that measure the ozone vertical distribution, the SBUV and SAGE (Stratospheric Aerosol and Gas Experiment) instruments for example, show that the largest changes are occurring in the lower stratosphere and upper troposphere. The goal of ozone measurement in the next decades will be to document the predicted recovery of the ozone layer as CFC (chlorofluorocarbon) levels decline. This will require a continuation of global measurements of total column ozone on a global basis, but using data from successor instruments to TOMS. Hyperspectral instruments capable of measuring in the UV will be needed for this purpose. Establishing the relative roles of chemistry and dynamics will require instruments to measure ozone in the troposphere and in the stratosphere with good vertical resolution. Instruments that can measure other chemicals important to ozone formation and destruction will also be needed.

  7. 2001 OZONE DESIGN VALUE

    EPA Science Inventory

    Ozone is generated by a complex atmoshperic chemical process. Industrial and automobile pollutants in the form of oxides of nitrogen and hydrocarbons react in the atmosphere when air is stagnant and temperatures are high to form ozone. Ozone is known to cause adverse health eff...

  8. 2020 OZONE DESIGN VALUE

    EPA Science Inventory

    Ozone is generated by a complex atmoshperic chemical process. Industrial and automobile pollutants in the form of oxides of nitrogen and hydrocarbons react in the atmosphere when air is stagnant and temperatures are high to form ozone. Ozone is known to cause adverse health eff...

  9. OZONE BYPRODUCT FORMATION

    EPA Science Inventory

    The use of ozone for water treatment has been increasing as ozone has great potential for degrading water pollutants and inactivating viruses, Giardia cysts, and Cryptosporidium oocysts. Although it appears that ozone generates less undesirable disinfection by-products (DBPs) th...

  10. Ozone Antimicrobial Efficacy

    EPA Science Inventory

    Ozone is a potent germicide that has been used extensively for water purification. In Europe, 90 percent of the municipal water systems are treated with ozone, and in France, ozone has been used to treat drinking water since 1903. However, there is limited information on the bioc...

  11. The origin of ozone

    NASA Astrophysics Data System (ADS)

    Grewe, V.

    2006-05-01

    Highest atmospheric ozone production rates can be found at around 30 km in the tropical stratosphere, leading to ozone mixing ratios of about 10 ppmv. Those stratospheric air masses are then transported to extra-tropical latitudes via the Brewer-Dobson circulation. This is considered the main mechanism to generate mid- and high latitude ozone. By applying the climate-chemistry models E39/C and MAECHAM4/CHEM, this view is investigated in more detail. The origin of ozone in the troposphere and stratosphere is analysed, by incorporating a diagnostics ("marked ozone origin tracers") into the models, which allows to identify the origin of ozone. In most regions the simulated local ozone concentration is dominated by local ozone production, i.e. less than 50% of the ozone at higher latitudes of the stratosphere is produced in the tropics, which conflicts with the idea that the tropics are the global source for stratospheric ozone. Although episodic stratospheric intrusions occur basically everywhere, the main ozone stratosphere-to-troposphere exchange is connected to exchange processes at the sub-tropical jet-stream. The simulated tropospheric influx of ozone amounts to 420 Tg per year, and originates in the Northern Hemisphere from the extra-tropical stratosphere, whereas in the Southern Hemisphere a re-circulation of tropical tropospheric ozone contributes most to the influx of ozone into the troposphere. In the model E39/C, the upper troposphere of both hemispheres is clearly dominated by tropical tropospheric ozone (40%-50%) except for northern summer hemisphere, where the tropospheric contribution (from the tropics as well as from the Northern Hemisphere) does not exceed 20%.

  12. Response of macaque bronchiolar epithelium to ambient concentrations of ozone.

    PubMed Central

    Harkema, J. R.; Plopper, C. G.; Hyde, D. M.; St George, J. A.; Wilson, D. W.; Dungworth, D. L.

    1993-01-01

    Recently, we reported that exposure to ambient concentrations of ozone, near the U.S. National Ambient Air Quality Standard (0.12 ppm), induced significant nasal epithelial lesions in a non-human primate, the bonnet monkey. The present study defines the effects of ambient concentrations of ozone on the surface epithelium lining respiratory bronchioles and on the underlying bronchiolar interstitium in these same monkeys. Bonnet monkeys were exposed to filtered air or to 0.15 or 0.30 ppm ozone 8 hours/day for 6 or 90 days. At the end of exposures, monkeys were anesthetized and killed by exsanguination. Microdissected bronchiolar airways of infusion-fixed lungs were evaluated morphometrically by light microscopy and quantitatively by scanning and transmission electron microscopy for ozone-induced epithelial changes. Hyperplasia of nonciliated, cuboidal epithelial cells and intraluminal accumulation of macrophages characterized ozone-induced lesions in respiratory bronchioles. There were no significant differences in epithelial thickness or cell numbers among ozone-exposed groups. Ozone-exposed epithelium was composed of 80% cuboidal and 20% squamous cells compared with 40% cuboidal and 60% squamous cells in filtered air controls. In addition, the arithmetic mean thickness of the surface epithelium, a measure of tissue mass per unit area of basal lamina, was significantly increased in all of the ozone-exposed groups. The number of cuboidal epithelial cells per surface area of basal lamina was increased above control values by 780% after 6 days exposure to 0.15 ppm, 777% after 90 days to 0.15 ppm, and 996% after 90 days exposure to 0.30 ppm. There was also a significant ozone-induced increase in the thickness of the bronchiolar interstitium that was due to an increase in both cellular and acellular components. These results demonstrate that exposure to low ambient concentrations of ozone, near the current. National Ambient Air Quality Standard, induces pulmonary lesions

  13. Projections of Future Summertime Ozone over the U.S.

    SciTech Connect

    Pfister, G. G.; Walters, Stacy; Lamarque, J. F.; Fast, Jerome D.; Barth, Mary; Wong, John; Done, James; Holland, Greg; Bruyere, Cindy

    2014-05-05

    This study uses a regional fully coupled chemistry-transport model to assess changes in surface ozone over the summertime U.S. between present and a 2050 future time period at high spatial resolution (12 km grid spacing) under the SRES A2 climate and RCP8.5 anthropogenic pre-cursor emission scenario. The impact of predicted changes in climate and global background ozone is estimated to increase surface ozone over most of the U.S; the 5th - 95th percentile range for daily 8-hour maximum surface ozone increases from 31-79 ppbV to 30-87 ppbV between the present and future time periods. The analysis of a set of meteorological drivers suggests that these mostly will add to increasing ozone, but the set of simulations conducted does not allow to separate this effect from that through enhanced global background ozone. Statistically the most robust positive feedbacks are through increased temperature, biogenic emissions and solar radiation. Stringent emission controls can counteract these feedbacks and if considered, we estimate large reductions in surface ozone with the 5th-95th percentile reduced to 27-55 ppbV. A comparison of the high-resolution projections to global model projections shows that even though the global model is biased high in surface ozone compared to the regional model and compared to observations, both the global and the regional model predict similar changes in ozone between the present and future time periods. However, on smaller spatial scales, the regional predictions show more pronounced changes between urban and rural regimes that cannot be resolved at the coarse resolution of global model. In addition, the sign of the changes in overall ozone mixing ratios can be different between the global and the regional predictions in certain regions, such as the Western U.S. This study confirms the key role of emission control strategies in future air quality predictions and demonstrates the need for considering degradation of air quality with future

  14. High concentration of surface ozone observed along the Khumbu Valley Nepal April 2007

    NASA Astrophysics Data System (ADS)

    Moore, G. W. K.; Semple, J. L.

    2009-07-01

    Increasing air pollution in Southeast Asia has the potential for dramatic impacts on the population and climate in relatively pristine regions such as the Himalaya. Recent measurements near Mount Everest indicate the presence of elevated levels of ozone at elevations from 5000m to 9000m that are the result of both the long-range transport of tropospheric pollutants from Southeast Asia as well as the descent of ozone-rich stratospheric air. Here we report on the first surface ozone concentration transect in the Mount Everest region. The data collected at elevations from 2900m to 5200m indicate an increase in concentration with height as well as 8-hour average exposures in excess of 140ppb. Satellite data and meteorological diagnostics suggest a stratospheric source for the high levels observed. The majority of values observed exceed guidelines for human exposure and therefore are of a magnitude to suggest that they are of physiological relevance.

  15. Overview of ozone bleaching

    SciTech Connect

    Sonnenberg, L.B.

    1995-12-31

    The potential impact of the pulp and paper industry on the environment may be reduced by replacing chlorine-based bleaching reagents with ozone. The reactivity of ozone coupled with the heterogeneity of pulp allows many types of reactions to occur during pulp bleaching. Ozone cleaves the aromatic rings and side chain double bonds in lignin in Criegee-type mechanisms. Activated carbon-hydrogen bonds are fragmented in lignin side chains, as well as Cl carbons of {beta}-glycosides, by way of a 1,3 dipolar insertion forming a hydrotrioxide intermediate. Ozone also attacks carbohydrates at acetal oxygens, depolymerizing at the glycosidic bond. Unsaturated sites are ozonated before aliphatic sites resulting in a predominance of lignin reactions over carbohydrate reactions until lignin is substantially removed from the pulp. Important factors in the successful application of ozone bleaching include minimizing ozone decomposition and other secondary reactions, reducing exposure of cellulose to high concentrations of ozone and radicals, and promoting uniform exposure of ozone to lignin. The quantity of chlorinated organic compounds in effluents can be drastically reduced by replacing chlorine-based bleaching reagents with ozone; less organochlorine is formed and there can be greater recycle of bleach plant wastes back to the recovery cycle. Recycling of bleach plant waste also reduces total organic loading in the effluent. The toxicity of ozone filtrates is variable compared to conventional filtrates and depends on several parameters including bleaching conditions, biological treatment, and target organisms.

  16. Ozone and the stratosphere

    NASA Technical Reports Server (NTRS)

    Shimazaki, Tatsuo

    1987-01-01

    It is shown that the stratospheric ozone is effective in absorbing almost all radiation below 300 nm at heights below 300 km. The distribution of global ozone in the troposphere and the lower stratosphere, and the latitudinal variations of the total ozone column over four seasons are considered. The theory of the ozone layer production is discussed together with catalytic reactions for ozone loss and the mechanisms of ozone transport. Special attention is given to the anthropogenic perturbations, such as SST exhaust gases and freon gas from aerosol cans and refrigerators, that may cause an extensive destruction of the stratospheric ozone layer and thus have a profound impact on the world climate and on life.

  17. Spring polar ozone behavior

    NASA Technical Reports Server (NTRS)

    Aikin, Arthur C.

    1992-01-01

    Understanding of the springtime behavior of polar stratospheric ozone as of mid 1990 is summarized. Heterogeneous reactions on polar stratospheric clouds as hypothesis for ozone loss are considered and a simplified description of the behavior of Antarctic ozone in winter and spring is given. Evidence that the situation is more complicated than described by the theory is produced. Many unresolved scientific issues remain and some of the most important problems are identified. Ozone changes each spring since 1979 have clearly established for the first time that man made chlorine compounds influence stratospheric ozone. Long before important advances in satellite and in situ investigations, it was Dobson's decision to place a total ozone measuring spectrometer at Halley Bay in Antarctica during the International Geophysical Year and subsequent continuous monitoring which led to the discovery that ozone was being destroyed each spring by chlorine processed by polar stratospheric clouds.

  18. Ozone trends: A review

    NASA Astrophysics Data System (ADS)

    Staehelin, J.; Harris, N. R. P.; Appenzeller, C.; Eberhard, J.

    2001-05-01

    Ozone plays a very important role in our atmosphere because it protects any living organisms at the Earth's surface against the harmful solar UVB and UVC radiation. In the stratosphere, ozone plays a critical role in the energy budget because it absorbs both solar UV and terrestrial IR radiation. Further, ozone in the tropopause acts as a strong greenhouse gas, and increasing ozone trends at these altitudes contribute to climate change. This review contains a short description of the various techniques that provided atmospheric ozone measurements valuable for long-term trend analysis. The anthropogenic emissions of substances that deplete ozone (chlorine- and bromine-containing volatile gases) have increased from the 1950s until the second half of the 1980s. The most severe consequence of the anthropogenic release of ozone-depleting substances is the "Antarctic ozone hole." Long-term observations indicate that stratospheric ozone depletion in the southern winter-spring season over Antarctica started in the late 1970s, leading to a strong decrease in October total ozone means. Present values are only approximately half of those observed prior to 1970. In the Arctic, large ozone depletion was observed in winter and spring in some recent years. Satellite and ground-based measurements show no significant trends in the tropics but significant long-term decreasing trends in the northern and southern midlatitudes (of the order of 2-4% per decade in the period from 1970 to 1996 and an acceleration in trends in the 1980s). Ozone at northern midlatitudes decreased by -7.4±2% per decade at 40 km above mean sea level, while ozone loss was small at 30 km. Large trends were found in the lower stratosphere, -5.1±1.8% at 20 km and -7.3±4.6% at 15 km, where the bulk of the ozone resides. The possibility of a reduction in the observed trends has been discussed recently, but it is very hard to distinguish this from the natural variability. As a consequence of the Montreal Protocol

  19. Understanding Emissions from Control-Related Equipment used in Oil and Gas Production Operations to Support EPA’s Air Quality Modeling of Ozone Non-attainment Areas

    EPA Science Inventory

    Oil and gas production has increased significantly in the United States over the past ten years. Improperly maintained and controlled oil and gas extraction and production (E&P) processes have the potential to emit significant amounts of pollutants that can impact human health an...

  20. Unraveling the sources of ground level ozone in the Intermountain Western United States using Pb isotopes.

    PubMed

    Christensen, John N; Weiss-Penzias, Peter; Fine, Rebekka; McDade, Charles E; Trzepla, Krystyna; Brown, Shaun T; Gustin, Mae Sexauer

    2015-10-15

    Ozone as an atmospheric pollutant is largely produced by anthropogenic precursors and can significantly impact human and ecosystem health, and climate. The U.S. Environmental Protection Agency has recently proposed lowering the ozone standard from 75 ppbv (MDA8 = Maximum Daily 8-Hour Average) to between 65 and 70 ppbv. This will result in remote areas of the Intermountain West that includes many U.S. National Parks being out of compliance, despite a lack of significant local sources. We used Pb isotope fingerprinting and back-trajectory analysis to distinguish sources of imported ozone to Great Basin National Park in eastern Nevada. During discrete Chinese Pb events (> 1.1 ng/m(3) & > 80% Asian Pb) trans-Pacific transported ozone was 5 ± 5.5 ppbv above 19 year averages for those dates. In contrast, concentrations during regional transport from the Los Angeles and Las Vegas areas were 15 ± 2 ppbv above the long-term averages, and those characterized by high-altitude transport 3 days prior to sampling were 19 ± 4ppbv above. However, over the study period the contribution of trans-Pacific transported ozone increased at a rate of 0.8 ± 0.3 ppbv/year, suggesting that Asian inputs will exceed regional and high altitude sources by 2015-2020. All of these sources will impact regulatory compliance with a new ozone standard, given increasing global background. PMID:25934382

  1. Rebound of Antarctic ozone

    NASA Astrophysics Data System (ADS)

    Salby, Murry; Titova, Evgenia; Deschamps, Lilia

    2011-05-01

    Restrictions on CFCs have led to a gradual decline of Equivalent Effective Stratospheric Chlorine (EESC). A rebound of Antarctic ozone, however, has remained elusive, masked by large interannual changes that dominate its current evolution. A positive response of ozone is not expected to emerge for at least 1-2 decades, possibly not for half a century. We show that interannual changes of the Antarctic ozone hole are accounted for almost perfectly by changes in dynamical forcing of the stratosphere. The close relationship enables dynamically-induced changes of ozone to be removed, unmasking the climate signal associated with CFCs. The component independent of dynamically-induced changes exhibits a clear upward trend over the last decade - the first signature of a rebound in Antarctic ozone. It enables ozone to be tracked relative to CFCs and other changes of climate.

  2. Ozone therapy in periodontics

    PubMed Central

    Gupta, G; Mansi, B

    2012-01-01

    Gingival and Periodontal diseases represent a major concern both in dentistry and medicine. The majority of the contributing factors and causes in the etiology of these diseases are reduced or treated with ozone in all its application forms (gas, water, oil). The beneficial biological effects of ozone, its anti-microbial activity, oxidation of bio-molecules precursors and microbial toxins implicated in periodontal diseases and its healing and tissue regeneration properties, make the use of ozone well indicated in all stages of gingival and periodontal diseases. The primary objective of this article is to provide a general review about the clinical applications of ozone in periodontics. The secondary objective is to summarize the available in vitro and in vivo studies in Periodontics in which ozone has been used. This objective would be of importance to future researchers in terms of what has been tried and what the potentials are for the clinical application of ozone in Periodontics. PMID:22574088

  3. Ozone flow visualization techniques

    NASA Technical Reports Server (NTRS)

    Dickerson, R. R.; Stedman, D. H.

    1981-01-01

    Flow visualization techniques using ozone for tracing gas flows are proposed whereby ozone is detected through its strong absorption of ultraviolet light, which is easily made visible with fluorescent materials, or through its reaction with nitric oxide to form excited nitrogen dioxide, which in relaxing emits detectable light. It is shown that response speeds in the kHz range are possible with an ultraviolet detection system for initial ozone concentrations of about 1%.

  4. The Antarctic ozone hole

    NASA Technical Reports Server (NTRS)

    Stolarski, Richard S.

    1988-01-01

    Processes that may be responsible for the thinning in the ozone layer above the South Pole are described. The chlorine catalytic cycle which destroys ozone is described, as are the major types of reactions that are believed to interfere with this cycle by forming chlorine reservoirs. The suspected contributions of polar stratospheric clouds to these processes are examined. Finally, the possibility that the ozone hole may be due more to a shift in atmospheric dynamics than to chemical destruction is addressed.

  5. An automated ozone photometer

    NASA Technical Reports Server (NTRS)

    Lavelle, Joseph R.

    1988-01-01

    A photometer capable of automatically measuring ozone concentration data to very high resolution during scientific research flights in the earth's atmosphere was developed at the NASA Ames Research Center. This instrument was recently deployed to study the ozone hole over Antarctica. Ozone is detected by absorbing 253.7-nm radiation from an ultraviolet lamp which shines through the sample of air and impinges on a vacuum phototube. A lower output from the phototube indicates more ozone present in the air sample. The photometer employs a CMOS 280 control, data collection, and storage.

  6. Climate variability modulates western US ozone air quality in spring via deep stratospheric intrusions

    NASA Astrophysics Data System (ADS)

    Lin, Meiyun; Fiore, Arlene M.; Horowitz, Larry W.; Langford, Andrew O.; Oltmans, Samuel J.; Tarasick, David; Rieder, Harald E.

    2015-05-01

    Evidence suggests deep stratospheric intrusions can elevate western US surface ozone to unhealthy levels during spring. These intrusions can be classified as `exceptional events', which are not counted towards non-attainment determinations. Understanding the factors driving the year-to-year variability of these intrusions is thus relevant for effective implementation of the US ozone air quality standard. Here we use observations and model simulations to link these events to modes of climate variability. We show more frequent late spring stratospheric intrusions when the polar jet meanders towards the western United States, such as occurs following strong La Niña winters (Niño3.4<-1.0 °C). While El Niño leads to enhancements of upper tropospheric ozone, we find this influence does not reach surface air. Fewer and weaker intrusion events follow in the two springs after the 1991 volcanic eruption of Mt. Pinatubo. The linkage between La Niña and western US stratospheric intrusions can be exploited to provide a few months of lead time during which preparations could be made to deploy targeted measurements aimed at identifying these exceptional events.

  7. Climate variability modulates western US ozone air quality in spring via deep stratospheric intrusions.

    PubMed

    Lin, Meiyun; Fiore, Arlene M; Horowitz, Larry W; Langford, Andrew O; Oltmans, Samuel J; Tarasick, David; Rieder, Harald E

    2015-01-01

    Evidence suggests deep stratospheric intrusions can elevate western US surface ozone to unhealthy levels during spring. These intrusions can be classified as 'exceptional events', which are not counted towards non-attainment determinations. Understanding the factors driving the year-to-year variability of these intrusions is thus relevant for effective implementation of the US ozone air quality standard. Here we use observations and model simulations to link these events to modes of climate variability. We show more frequent late spring stratospheric intrusions when the polar jet meanders towards the western United States, such as occurs following strong La Niña winters (Niño3.4<-1.0 °C). While El Niño leads to enhancements of upper tropospheric ozone, we find this influence does not reach surface air. Fewer and weaker intrusion events follow in the two springs after the 1991 volcanic eruption of Mt. Pinatubo. The linkage between La Niña and western US stratospheric intrusions can be exploited to provide a few months of lead time during which preparations could be made to deploy targeted measurements aimed at identifying these exceptional events. PMID:25964012

  8. Climate variability modulates western US ozone air quality in spring via deep stratospheric intrusions

    PubMed Central

    Lin, Meiyun; Fiore, Arlene M.; Horowitz, Larry W.; Langford, Andrew O.; Oltmans, Samuel J.; Tarasick, David; Rieder, Harald E.

    2015-01-01

    Evidence suggests deep stratospheric intrusions can elevate western US surface ozone to unhealthy levels during spring. These intrusions can be classified as ‘exceptional events', which are not counted towards non-attainment determinations. Understanding the factors driving the year-to-year variability of these intrusions is thus relevant for effective implementation of the US ozone air quality standard. Here we use observations and model simulations to link these events to modes of climate variability. We show more frequent late spring stratospheric intrusions when the polar jet meanders towards the western United States, such as occurs following strong La Niña winters (Niño3.4<−1.0 °C). While El Niño leads to enhancements of upper tropospheric ozone, we find this influence does not reach surface air. Fewer and weaker intrusion events follow in the two springs after the 1991 volcanic eruption of Mt. Pinatubo. The linkage between La Niña and western US stratospheric intrusions can be exploited to provide a few months of lead time during which preparations could be made to deploy targeted measurements aimed at identifying these exceptional events. PMID:25964012

  9. The Characteristics Improvement of Ozone Water Production by Multi-layer Electrodes at Water Electrolysis Cell by Solid Polymer Electrolyte

    NASA Astrophysics Data System (ADS)

    Ohba, Takahiro; Kusunoki, Hironobu; Sunakawa, Daisuke; Araki, Takuto; Onda, Kazuo

    Ozone is recently used for many purposes as an environmental friendly oxidant, so the ozone production device with high ozone concentration and low production energy is desired. One of the candidates for such device is the ozone water production by water electrolysis cell using the solid polymer electrolyte with PbO2 anode catalyst, which has merits to be compact and to produce high-concentration ozone water directly by the deionized water electrolysis. In this study, we have tested ozone water production by changing electrodes and electrolytes constitution in order to improve the ozone production performance. Tested two electrolytes are Nafion117 and a membrane-electrode assembly (MEA) with Pt catalyst on cathode side of Nafion117. Tested two electrodes are mono-layer of Ti expanded metal and four different mesh layers of Ti expanded metal. Ozone water production tests are performed under long-term operations changing temperature and flow rate to optimize experimental conditions. The voltage-current characteristic for electrolysis cell have been improved significantly, when the electrode is four layers of Ti metal and the electrolyte is the MEA with Pt catalyst. The stable ozone water concentration has been obtained by operating the cell for about 8 hours. The optimum temperature and water flow rate for ozone water production are 25˜30° and 33L/h, respectively. Furthermore, the optimum overpotential was measured by a reference electrode at the cathode-side MEA, and the anode catalyst suitable for ozone water production was identified to be βPbO2 by the X ray diffraction pattern.

  10. Polar Ozone Workshop. Abstracts

    NASA Technical Reports Server (NTRS)

    Aikin, Arthur C.

    1988-01-01

    Results of the proceedings of the Polar Ozone Workshop held in Snowmass, CO, on May 9 to 13, 1988 are given. Topics covered include ozone depletion, ozonometry, polar meteorology, polar stratospheric clouds, remote sensing of trace gases, atmospheric chemistry and dynamical simulations.

  11. The Antarctic Ozone Hole.

    ERIC Educational Resources Information Center

    Stolarski, Richard S.

    1988-01-01

    Discusses the Airborne Antarctic Ozone Experiment (1987) and the findings of the British Antarctic Survey (1985). Proposes two theories for the appearance of the hole in the ozone layer over Antarctica which appears each spring; air pollution and natural atmospheric shifts. Illustrates the mechanics of both. Supports worldwide chlorofluorocarbon…

  12. Surface Ozone in Kiev

    NASA Astrophysics Data System (ADS)

    Shavrina, A. V.; Mikulskaya, I. A.; Kiforenko, S. I.; Blum, O. B.; Sheminova, V. A.; Veles, A. A.

    The study of total ozone over Kiev and its concentration changes with height in the troposphere has been made on the base of ground-based observations with the infrared Fourier-spectrometer in the Main Astronomical Observatory of National Academy of Sciences of Ukraine (MAO NASU) as part of ESA-NIVR-KNMI project no 2907 "OMI validation by ground based remote sensing: ozone columns and atmospheric profiles "(2005-2008) [1,2,4]. Ground-level ozone in Kiev for an episode of its high concentrations in August 2000 was also simulated with the model of urban air pollution UAM-V [5,6]. In 2008 the satellite data Aura-OMI on profiles of ozone in the atmosphere OMO3PR became available (http://disc.sci.gsfc.nasa.gov/ Aura/data-holdings/OMI/ omo3pr_v003.shtml). They include ozone content in the lower layer of the atmosphere, beginning from 2005, which can be used to evaluate the ground-level ozone in all cities of Ukraine. The comparison of the data of ozone air pollution in Kiev (ozone - the pollutant of the first class of danger) and medical statistics data of of respiratory system (RS) diseases of the city population was carried out with the package "Statistica". A regression analysis, prognostic regression modelling, and retrospective prognosis of the epidemiological situation with respect to RS pathologies in Kiev in 2000-2006 were performed.

  13. Ozone and temperature trends

    NASA Technical Reports Server (NTRS)

    Stolarski, Richard S.; Fioletov, Vitali; Bishop, Lane; Godin, Sophie; Bojkov, Rumen D.; Kirchhoff, Volker; Chanin, Marie-Lise; Zawodny, Joseph M.; Zerefos, Christos S.; Chu, William

    1991-01-01

    An update of the extensive reviews of the state of knowledge of measured ozone trends published in the Report of the International Ozone Trends Panel is presented. The update contains a review of progress since these reports, including reviewing of the ozone records, in most cases through March 1991. Also included are some new, unpublished reanalyses of these records including a complete reevaluation of 29 stations located in the former Soviet Union. The major new advance in knowledge of the measured ozone trend is the existence of independently calibrated satellite data records from the Total Ozone Mapping Spectrometer (TOMS) and Stratospheric Aerosol and Gas Experiment (SAG) instruments. These confirm many of the findings, originally derived from the Dobson record, concerning northern mid-latitude changes in ozone. We now have results from several instruments, whereas the previously reported changes were dependent on the calibration of a single instrument. This update will compare the ozone records from many different instruments to determine whether or not they provide a consistent picture of the ozone change that has occurred in the atmosphere. The update also briefly considers the problem of stratospheric temperature change. As in previous reports, this problem received significantly less attention, and the report is not nearly as complete. This area needs more attention in the future.

  14. Saving Our Ozone Shield.

    ERIC Educational Resources Information Center

    Lacoste, Beatrice

    1992-01-01

    Discusses the introduction and continued use of chlorofluorocarbons (CFCs) as related to stratospheric ozone depletion. Presents the characteristics of CFCs conducive to the chemical reaction with ozone, the history of CFC use and detection of related environmental problems, health hazards, and alternatives to CFC use. (MCO)

  15. Observing trends in total ozone and extreme ozone events

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2014-05-01

    The ozone layer in the stratosphere has been recovering since the 1989 Montreal Protocol reduced the use of ozone-destroying chlorofluorocarbons. Fitzka et al. observed trends in total ozone levels and the vertical distribution of ozone at Hoher Sonnblick, a mountain in Austria, from 1994 to 2011.

  16. Ozone from Wildfires: Peering through the Smog

    NASA Astrophysics Data System (ADS)

    Jaffe, D. A.; Baylon, P.; Wigder, N. L.; Collier, S.; Zhou, S.; Zhang, Q.; Alvarado, M. J.

    2014-12-01

    In the western US, many areas are near the current air quality standard for O3. Yet there is substantial inter-annual variability (IAV) in the number of days that exceed the O3 air quality threshold (currently 75 ppbv for an 8-hour average). We propose that wildfires are the dominant cause for this IAV. However there are large uncertainties around O3 production from wildfires due to numerous complicating factors. Ozone formation in wildfire plumes differs substantially from urban O3 production in several ways: substantial variations in the emissions, much larger aerosol loadings, a much greater variety of reactive and oxygenated VOCs, rapid and substantial formation of PAN and very different sources of HOx in the plume. These factors make it challenging to model wildfire impacts on photochemistry in the usual way. In this presentation we will show examples of three common situations based on data from the Mt. Bachelor Observatory: Rapid O3 formation (within one day) in a wildfire plume. Slow, but substantial, O3 formation (over days to a week) in a wildfire plume. No detectable O3 formation in a wildfire plume. We will interpret these results with respect to the observed NOy mixing ratios, the photochemical environment, the combustion efficiency, the plume transport and other factors and suggest some key experiments and modeling studies that can help further our understanding of wildfire O3 production.

  17. Long-Term Ozone Exposure Attenuates 1-Nitronaphthalene–Induced Cytotoxicity in Nasal Mucosa

    PubMed Central

    Lee, Myong Gyong; Wheelock, Åsa M.; Boland, Bridget; Plopper, Charles G.

    2008-01-01

    1-Nitronaphthalene (1-NN) and ozone are cytotoxic air pollutants commonly found as components of photochemical smog. The mechanism of toxicity for 1-NN involves bioactivation by cytochrome P450s and subsequent adduction to proteins. Previous studies have shown that 1-NN toxicity in the lung is considerably higher in rats after long-term exposure to ozone compared with the corresponding filtered air–exposed control rats. The aim of the present study was to establish whether long-term exposure to ozone alters the susceptibility of nasal mucosa to the bioactivated toxicant, 1-NN. Adult male Sprague-Dawley rats were exposed to filtered air or 0.8 ppm ozone for 8 hours per day for 90 days, followed by a single treatment with 0, 12.5, or 50.0 mg/kg 1-NN by intraperitoneal injection. The results of the histopathologic analyses show that the nasal mucosa of rats is a target of systemic 1-NN, and that long-term ozone exposure markedly lessens the severity of injury, as well as the protein adduct formation by reactive 1-NN metabolites. The antagonistic effects were primarily seen in the nasal transitional epithelium, which corresponds to the main site of histologic changes attributed to ozone exposure (goblet cell metaplasia and hyperplasia). Long-term ozone exposure did not appear to alter susceptibility to 1-NN injury in other nasal regions. This study shows that long-term ozone exposure has a protective effect on the susceptibility of nasal transitional epithelium to subsequent 1-NN, a result that clearly contrasts with the synergistic toxicological effect observed in pulmonary airway epithelium in response to the same exposure regimen. PMID:17901409

  18. The Hole in the Ozone Layer.

    ERIC Educational Resources Information Center

    Hamers, Jeanne S.; Jacob, Anthony T.

    This document contains information on the hole in the ozone layer. Topics discussed include properties of ozone, ozone in the atmosphere, chlorofluorocarbons, stratospheric ozone depletion, effects of ozone depletion on life, regulation of substances that deplete the ozone layer, alternatives to CFCs and Halons, and the future of the ozone layer.…

  19. The Two Faces of Ozone.

    ERIC Educational Resources Information Center

    Monastersky, Richard

    1989-01-01

    Provides answers to questions regarding the ozone problem: (1) nature of ozone in the troposphere and stratosphere; (2) possibility of sending the excess ozone at ground level to the stratosphere; (3) possibility of producing pure ozone and carrying it to the stratosphere; and (4) banning chlorofluorocarbons. (YP)

  20. Fundamentals of ISCO Using Ozone

    EPA Science Inventory

    In situ chemical oxidation (ISCO) using ozone involves the introduction of ozone gas (O3) into the subsurface to degrade organic contaminants of concern. Ozone is tri-molecular oxygen (O2) that is a gas under atmospheric conditions and is a strong oxidant. Ozone may react with ...

  1. Who is more affected by ozone pollution? A systematic review and meta-analysis.

    PubMed

    Bell, Michelle L; Zanobetti, Antonella; Dominici, Francesca

    2014-07-01

    Ozone is associated with adverse health; however, less is known about vulnerable/sensitive populations, which we refer to as sensitive populations. We systematically reviewed epidemiologic evidence (1988-2013) regarding sensitivity to mortality or hospital admission from short-term ozone exposure. We performed meta-analysis for overall associations by age and sex; assessed publication bias; and qualitatively assessed sensitivity to socioeconomic indicators, race/ethnicity, and air conditioning. The search identified 2,091 unique papers, with 167 meeting inclusion criteria (73 on mortality and 96 on hospitalizations and emergency department visits, including 2 examining both mortality and hospitalizations). The strongest evidence for ozone sensitivity was for age. Per 10-parts per billion increase in daily 8-hour ozone concentration, mortality risk for younger persons, at 0.60% (95% confidence interval (CI): 0.40, 0.80), was statistically lower than that for older persons, at 1.27% (95% CI: 0.76, 1.78). Findings adjusted for publication bias were similar. Limited/suggestive evidence was found for higher associations among women; mortality risks were 0.39% (95% CI: -0.22, 1.00) higher than those for men. We identified strong evidence for higher associations with unemployment or lower occupational status and weak evidence of sensitivity for racial/ethnic minorities and persons with low education, in poverty, or without central air conditioning. Findings show that some populations, especially the elderly, are particularly sensitive to short-term ozone exposure. PMID:24872350

  2. Stratospheric ozone depletion

    PubMed Central

    Rowland, F. Sherwood

    2006-01-01

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290–320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime—the ‘Antarctic ozone hole’. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules. PMID:16627294

  3. Stratospheric ozone depletion.

    PubMed

    Rowland, F Sherwood

    2006-05-29

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290-320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime-the 'Antarctic ozone hole'. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules. PMID:16627294

  4. A Total Ozone Dependent Ozone Profile Climatology Based on Ozone-Sondes and Aura MLS Data

    NASA Astrophysics Data System (ADS)

    Labow, G. J.; McPeters, R. D.; Ziemke, J. R.

    2014-12-01

    A new total ozone-based ozone profile climatology has been created for use in satellite and/or ground based ozone retrievals. This climatology was formed by combining data from the Microwave Limb Sounder (MLS) with data from balloon sondes and binned by zone and total ozone. Because profile shape varies with total column ozone, this climatology better captures the ozone variations than the previously used seasonal climatologies, especially near the tropopause. This is significantly different than ozone climatologies used in the past as there is no time component. The MLS instrument on Aura has excellent latitude coverage and measures ozone profiles daily from the upper troposphere to the lower mesosphere at ~3.5 km resolution. Almost a million individual MLS ozone measurements are merged with data from over 55,000 ozonesondes which are then binned as a function of total ozone. The climatology consists of average ozone profiles as a function of total ozone for six 30 degree latitude bands covering altitudes from 0-75 km (in Z* pressure altitude coordinates). This new climatology better represents the profile shape as a function of total ozone than previous climatologies and shows some remarkable and somewhat unexpected correlations between total ozone and ozone in the lower altitudes, particularly in the lower and middle troposphere. These data can also be used to infer biases and errors in either the MLS retrievals or ozone sondes.

  5. Ozone - plant surface reactions an important ozone loss term?

    NASA Astrophysics Data System (ADS)

    Hansel, Armin; Jud, Werner; Fischer, Lukas; Canaval, Eva; Wohlfahrt, Georg; Tissier, Alain

    2015-04-01

    Elevated tropospheric ozone concentrations are considered a toxic threat to plants responsible for global crop losses with associated economic costs of several billions dollar per year. Plant injuries have been related to the uptake of ozone through stomatal pores and oxidative effects damaging the internal leaf tissue. But a striking question remains: How much ozone enters the plant through open stomata and how much ozone is lost by chemical reactions at the plant surface? Until now surface losses are estimated from measured total ozone deposition fluxes and calculated stomatal conductance values. While stomatal conductance of CO2 and H2O is well understood and extensively used in describing plant atmosphere gas exchange, stomatal conductance of ozone is not well known. Here we use different Nicotiana tabacum varieties and find that surface reactions of ozone with diterpenoids synthesized by glandular trichomes reduce ozone flux through open stomata. Our measurements reveal that fast ozone loss at the plant surface is accompanied with prompt release of oxygenated volatile compounds. In the ozone fumigation experiments of different Nicotiana tabacum varieties the release of specific volatile oxy-VOCs allowed to identify the semi volatile precursor compounds at the plant surface. Ozone fumigation experiments with Norway spruce (Picea abies) and Scots Pine (Pinus sylvestris), two common species in the Northern Hemisphere, show also a significant ozone loss at the plant surface for Picea abies. Fluid dynamic calculations of ozone transport in the diffusive leaf boundary layer reveal a vertical but no horizontal ozone gradient thus reducing ozone fluxes through the pores in case of efficient ozone scavenging plant surfaces. We explain this efficient ozone protection mechanism by the porous surface architecture of plants in combination with unsaturated semi-volatile compounds deposited at the plant surface. These results show that unsaturated semi-volatile compounds at

  6. Low density solid ozone

    SciTech Connect

    Teolis, B. D.; Fama, M.; Baragiola, R. A.

    2007-08-21

    We report a very low density ({approx}0.5 g/cm{sup 3}) structure of solid ozone. It is produced by irradiation of solid oxygen with 100 keV protons at 20 K followed by heating to sublime unconverted oxygen. Upon heating to 47 K the porous ozone compacts to a density of {approx}1.6 g/cm{sup 3} and crystallizes. We use a detailed analysis of the main infrared absorption band of the porous ozone to interpret previous research, where solid oxygen was irradiated by UV light and keV electrons.

  7. Arctic ozone loss

    SciTech Connect

    Zurer, P.S.

    1989-03-06

    Scientists have returned from the first comprehensive probe of the Arctic stratosphere with unexpectedly dire results: The winter atmosphere in the north polar region is loaded with the same destructive chlorine compounds that cause the Antarctic ozone hole. Atmospheric researchers who only a few weeks ago were comforted by the thought that the warmer Northern Hemisphere is strongly protected from the processes that lead to massive losses of ozone during spring in Antarctica now see very little standing in the way of an Arctic ozone hole.

  8. The Impact of Meteorology on Ozone Levels in the Lake Tahoe Basin

    NASA Astrophysics Data System (ADS)

    Theiss, Sandra

    The Lake Tahoe Basin is located on the California-Nevada border and occasionally experiences elevated levels of ozone exceeding the 70 ppb California Air Resources Board (CARB) ambient air quality standard (8-hour average). Previous studies indicate that both the local generation of ozone in the Basin and long-range transport from out-of-Basin sources are important in contributing to ozone exceedances, but little is known about the impact of meteorology on the distribution of ozone source regions. In order to develop a better understanding of the factors affecting ozone levels and sources in the Lake Tahoe Basin, this study combines observational data from a 2010 and 2012 summer field campaigns, HYSPLIT back trajectories, and WRF model output to examine the meteorological influences of ozone transport in the topographically complex Lake Tahoe Basin. Findings from the field work portions of this study include enhanced background ozone levels at higher elevations, the local circulation pattern of lake breezes occurring at Lake level sites, and an indication that ozone precursors are coming off the Lake. Our analysis also showed that if transport of ozone does occur, it is more likely to come from the San Joaquin Valley to the south rather than originate in the large cities to the west, such as Sacramento and San Francisco. Analysis of modeled PBL schemes as compared with observational data showed that the ACM2 PBL scheme best represented the geographical domain. The ACM2 PBL scheme was then used to show wind circulation patterns in the Lake Tahoe Basin and concluded that there is decent vertical mixing over the Basin and no indication of ozone transport from the west however some indication of transport from the east. Overall this study concludes that transport from the west is less significant than transport from the south and east, and that transport only influences ozone values at higher elevations. Within the Basin itself (at lower elevations), local factors

  9. Ozone Therapy in Dentistry

    PubMed Central

    Domb, William C

    2014-01-01

    Summary The 21st century dental practice is quite dynamic. New treatment protocols and new materials are being developed at a rapid pace. Ozone dental therapy falls into the category of new treatment protocols in dentistry, yet ozone is not new at all. Ozone therapy is already a major treatment modality in Europe, South America and a number of other countries. What is provided here will not be an exhaustive scientific treatise so much as a brief general introduction into what dentists are now doing with ozone therapies and the numerous oral/systemic links that make this subject so important for physicians so that, ultimately, they may serve their patients more effectively and productively. PMID:25363268

  10. Development of fuzzy system and nonlinear regression models for ozone and PM2.5 air quality forecasts

    NASA Astrophysics Data System (ADS)

    Lin, Yiqiu

    2007-12-01

    Ozone forecast models using nonlinear regression (NLR) have been successfully applied to daily ozone forecast for seven metro areas in Kentucky, including Ashland, Bowling Green, Covington, Lexington, Louisville, Owensboro, and Paducah. In this study, the updated 2005 NLR ozone forecast models for these metro areas were evaluated on both the calibration data sets and independent data sets. These NLR ozone forecast models explained at least 72% of the variance of the daily peak ozone. Using the models to predict the ozone concentrations during the 2005 ozone season, the metro area mean absolute errors (MAEs) of the model hindcasts ranged from 5.90 ppb to 7.20 ppb. For the model raw forecasts, the metro area MAEs ranged from 7.90 ppb to 9.80 ppb. Based on previously developed NLR ozone forecast models for those areas, Takagi-Sugeno fuzzy system models were developed for the seven metro areas. The fuzzy "c-means" clustering technique coupled with an optimal output predefuzzification approach (least square method) was used to train the Takagi-Sugeno fuzzy system. Two types of fuzzy models, basic fuzzy and NLR-fuzzy system models, were developed. The basic fuzzy and NLR-fuzzy models exhibited essentially equivalent performance to the existing NLR models on 2004 ozone season hindcasts and forecasts. Both types of fuzzy models had, on average, slightly lower metro area averaged MAEs than the NLR models. Among the seven Kentucky metro areas Ashland, Covington, and Louisville are currently designated nonattainment areas for both ground level O 3 and PM2.5. In this study, summer PM2.5 forecast models were developed for providing daily average PM2.5 forecasts for the seven metro areas. The performance of the PM2.5 forecast models was generally not as good as that of the ozone forecast models. For the summer 2004 model hindcasts, the metro-area average MAE was 5.33 mug/m 3. Exploratory research was conducted to find the relationship between the winter PM2.5 concentrations and

  11. The ozone backlash

    SciTech Connect

    Taubes, G.

    1993-06-11

    While evidence for the role of chlorofluorocarbons in ozone depletion grows stronger, researchers have recently been subjected to vocal public criticism of their theories-and their motives. Their understanding of the mechanisms of ozone destruction-especially the annual ozone hole that appears in the Antarctic-has grown stronger, yet everywhere they go these days, they seem to be confronted by critics attacking their theories as baseless. For instance, Rush Limbaugh, the conservative political talk-show host and now-best-selling author of The Way Things Ought to Be, regularly insists that the theory of ozone depletion by CFCs is a hoax: bladerdash and poppycock. Zoologist Dixy Lee Ray, former governor of the state of Washington and former head of the Atomic Energy Commission, makes the same argument in her book, Trashing the Planet. The Wall Street Journal and National Review have run commentaries by S. Fred Singer, a former chief scientists for the Department of Transportation, purporting to shoot holes in the theory of ozone depletion. Even the June issue of Omni, a magazine with a circulation of more than 1 million that publishes a mixture of science and science fiction, printed a feature article claiming to expose ozone research as a politically motivated scam.

  12. Reforestation as a novel abatement and compliance measure for ground-level ozone.

    PubMed

    Kroeger, Timm; Escobedo, Francisco J; Hernandez, José L; Varela, Sebastián; Delphin, Sonia; Fisher, Jonathan R B; Waldron, Janice

    2014-10-01

    High ambient ozone (O3) concentrations are a widespread and persistent problem globally. Although studies have documented the role of forests in removing O3 and one of its precursors, nitrogen dioxide (NO2), the cost effectiveness of using peri-urban reforestation for O3 abatement purposes has not been examined. We develop a methodology that uses available air quality and meteorological data and simplified forest structure growth-mortality and dry deposition models to assess the performance of reforestation for O3 precursor abatement. We apply this methodology to identify the cost-effective design for a hypothetical 405-ha, peri-urban reforestation project in the Houston-Galveston-Brazoria O3 nonattainment area in Texas. The project would remove an estimated 310 tons of (t) O3 and 58 t NO2 total over 30 y. Given its location in a nitrogen oxide (NOx)-limited area, and using the range of Houston area O3 production efficiencies to convert forest O3 removal to its NOx equivalent, this is equivalent to 127-209 t of the regulated NOx. The cost of reforestation per ton of NOx abated compares favorably to that of additional conventional controls if no land costs are incurred, especially if carbon offsets are generated. Purchasing agricultural lands for reforestation removes this cost advantage, but this problem could be overcome through cost-share opportunities that exist due to the public and conservation benefits of reforestation. Our findings suggest that peri-urban reforestation should be considered in O3 control efforts in Houston, other US nonattainment areas, and areas with O3 pollution problems in other countries, wherever O3 formation is predominantly NOx limited. PMID:25201970

  13. Reforestation as a novel abatement and compliance measure for ground-level ozone

    PubMed Central

    Kroeger, Timm; Escobedo, Francisco J.; Hernandez, José L.; Varela, Sebastián; Delphin, Sonia; Fisher, Jonathan R. B.; Waldron, Janice

    2014-01-01

    High ambient ozone (O3) concentrations are a widespread and persistent problem globally. Although studies have documented the role of forests in removing O3 and one of its precursors, nitrogen dioxide (NO2), the cost effectiveness of using peri-urban reforestation for O3 abatement purposes has not been examined. We develop a methodology that uses available air quality and meteorological data and simplified forest structure growth-mortality and dry deposition models to assess the performance of reforestation for O3 precursor abatement. We apply this methodology to identify the cost-effective design for a hypothetical 405-ha, peri-urban reforestation project in the Houston–Galveston–Brazoria O3 nonattainment area in Texas. The project would remove an estimated 310 tons of (t) O3 and 58 t NO2 total over 30 y. Given its location in a nitrogen oxide (NOx)-limited area, and using the range of Houston area O3 production efficiencies to convert forest O3 removal to its NOx equivalent, this is equivalent to 127–209 t of the regulated NOx. The cost of reforestation per ton of NOx abated compares favorably to that of additional conventional controls if no land costs are incurred, especially if carbon offsets are generated. Purchasing agricultural lands for reforestation removes this cost advantage, but this problem could be overcome through cost-share opportunities that exist due to the public and conservation benefits of reforestation. Our findings suggest that peri-urban reforestation should be considered in O3 control efforts in Houston, other US nonattainment areas, and areas with O3 pollution problems in other countries, wherever O3 formation is predominantly NOx limited. PMID:25201970

  14. The Impact of Emission and Climate Change on Ozone in the United States under Representative Concentration Pathways (RCPs)

    SciTech Connect

    Gao, Yang; Fu, Joshua S.; Drake, John B.; Lamarque, J.-F.; Liu, Yang

    2013-09-27

    Dynamical downscaling was applied in this study to link the global climate-chemistry model Community Atmosphere Model (CAM-Chem) with the regional models: Weather Research and Forecasting (WRF) Model and Community Multi-scale Air Quality (CMAQ). Two Representative Concentration Pathway (RCP) scenarios (RCP 4.5 and RCP 8.5) were used to evaluate the climate impact on ozone concentrations in 2050s. Ozone concentrations in the lower-mid troposphere (surface to ~300 hPa), from mid- to high latitudes in the Northern Hemisphere (NH), show decreasing trends in RCP 4.5 between 2000s and 2050s, with the largest decrease of 4-10 ppbv occurring in the summer and the fall; and increasing trends (2-12 ppbv) in RCP 8.5 resulting from the increased methane emissions. In RCP 8.5, methane emissions increase by ~60% by the end of 2050s, accounting for more than 90% of ozone increases in summer and fall, and 60-80% in spring and winter. Under the RCP 4.5 scenario, in the summer when photochemical reactions are the most active, the large ozone precursor emissions reduction leads to the greatest decrease of downscaled surface ozone concentrations, ranging from 6 to 10 ppbv. However, a few major cities show ozone increases of 3 to 7 ppbv due to weakened NO titration. Under the RCP 8.5 scenario, in winter, downscaled ozone concentrations increase across nearly the entire continental US in winter, ranging from 3 to 10 ppbv due to increased methane emissions and enhanced stratosphere-troposphere exchange (STE). More intense heat waves are projected to occur by the end of 2050s in RCP 8.5, leading to more than 8 ppbv of the maximum daily 8-hour daily average (MDA8) ozone during the heat wave days than other days; this indicates the dramatic impact heat waves exert on high frequency ozone events.

  15. Bayesian Maximum Entropy Integration of Ozone Observations and Model Predictions: An Application for Attainment Demonstration in North Carolina

    PubMed Central

    de Nazelle, Audrey; Arunachalam, Saravanan; Serre, Marc L.

    2010-01-01

    States in the USA are required to demonstrate future compliance of criteria air pollutant standards by using both air quality monitors and model outputs. In the case of ozone, the demonstration tests aim at relying heavily on measured values, due to their perceived objectivity and enforceable quality. Weight given to numerical models is diminished by integrating them in the calculations only in a relative sense. For unmonitored locations, the EPA has suggested the use of a spatial interpolation technique to assign current values. We demonstrate that this approach may lead to erroneous assignments of non-attainment and may make it difficult for States to establish future compliance. We propose a method that combines different sources of information to map air pollution, using the Bayesian Maximum Entropy (BME) Framework. The approach gives precedence to measured values and integrates modeled data as a function of model performance. We demonstrate this approach in North Carolina, using the State’s ozone monitoring network in combination with outputs from the Multiscale Air Quality Simulation Platform (MAQSIP) modeling system. We show that the BME data integration approach, compared to a spatial interpolation of measured data, improves the accuracy and the precision of ozone estimations across the State. PMID:20590110

  16. MULTIPOLLUTANT METHODS - METHODS FOR OZONE AND OZONE PRECURSORS

    EPA Science Inventory

    This task involves the development and testing of methods for monitoring ozone and compounds associated with the atmospheric chemistry of ozone production both as precursors and reaction products. Although atmospheric gases are the primary interest, separation of gas and particl...

  17. Ozone Depletion by Hydrofluorocarbons

    NASA Astrophysics Data System (ADS)

    Hurwitz, M.; Fleming, E. L.; Newman, P. A.; Li, F.; Mlawer, E. J.; Cady-Pereira, K. E.; Bailey, R.

    2015-12-01

    Hydrofluorocarbons (HFCs) are second-generation replacements for the chlorofluorocarbons (CFCs), halons and other substances that caused the 'ozone hole'. Atmospheric concentrations of HFCs are projected to increase dramatically in the coming decades. Coupled chemistry-climate simulations forced by these projections show that HFCs will impact the global atmosphere in 2050. As strong radiative forcers, HFCs modulate atmospheric temperature, thereby changing ozone-destroying catalytic cycles and enhancing the stratospheric circulation. These changes lead to a weak depletion of stratospheric ozone. Sensitivity simulations with the NASA Goddard Space Flight Center (GSFC) 2D model show that HFC-125 is the most important contributor to atmospheric change in 2050, as compared with HFC-23, HFC-32, HFC-134a and HFC-143a. Incorporating the interactions between chemistry, radiation and dynamics, for a likely 2050 climate, ozone depletion potentials (ODPs) for HFCs range from 4.3x10-4 to 3.5x10-2; previously HFCs were assumed to have negligible ODPs since these species lack chlorine or bromine atoms. The ozone impacts of HFCs are further investigated with the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM). The GEOSCCM is a three-dimensional, fully coupled ocean-atmosphere model with interactive stratospheric chemistry. Sensitivity simulations in which CO2, CFC-11 and HCFC-22 are enhanced individually are used as proxies for the atmospheric response to the HFC concentrations expected by the mid-21st century. Sensitivity simulations provide quantitative estimates of the impacts of these greenhouse gases on global total ozone, and can be used to assess their effects on the recovery of Antarctic ozone.

  18. Ozonation of Canadian Athabasca asphaltene

    NASA Astrophysics Data System (ADS)

    Cha, Zhixiong

    Application of ozonation in the petrochemical industry for heavy hydrocarbon upgrading has not been sufficiently explored. Among heavy hydrocarbons, asphaltenes are the heaviest and the most difficult fractions for analysis and treatment. Therefore, ozonation of asphaltenes presents an interesting application in the petrochemical industry. Commercial application of ozonation in the petrochemical industry has three obstacles: availability of an ozone-resistant and environmentally friendly solvent, the precipitation of ozonation intermediates during reaction, and recovery of the solvent and separation of the ozonation products. Preliminary ozonation of Athabasca oil sands asphaltene in nonparticipating solvents encountered serious precipitation of the ozonation intermediates. The precipitated intermediates could be polymeric ozonides and intermolecular ozonides or polymeric peroxides. Because the inhomogeneous reaction medium caused low ozone efficiency, various participating solvents such as methanol and acetic acid were added to form more soluble hydroperoxides. The mass balance results showed that on average, one asphaltene molecule reacted with 12 ozone molecules through the electrophilic reaction and the subsequent decomposition of ozonation intermediates generated acetone extractable products. GC/MS analysis of these compounds indicated that the free radical reactions could be important for generation of volatile products. The extensively ozonated asphaltene in the presence of participating solvents were refluxed with methanol to generate more volatile products. GC/MS analysis of the methanol-esterified ozonation products indicated that most volatile products were aliphatic carboxylic acid esters generated through cleavage of substituents. Reaction kinetics study showed that asphaltene ozonation was initially a diffusion rate-controlled reaction and later developed to a chemical reaction rate-controlled reaction after depletion of the reactive aromatic sites

  19. Ozone Contamination in Aircraft Cabins. Appendix A: Ozone toxicity

    NASA Technical Reports Server (NTRS)

    Melton, C. E.

    1979-01-01

    The recommendation that at various altitudes the amount of air with which ozone has mixed changes, thus changing the volume per volume relationship is discussed. The biological effects of ozone on human health and the amount of ozone necessary to produce symptoms were investigated.

  20. Children's Models of the Ozone Layer and Ozone Depletion.

    ERIC Educational Resources Information Center

    Christidou, Vasilia; Koulaidis, Vasilis

    1996-01-01

    The views of 40 primary students on ozone and its depletion were recorded through individual, semi-structured interviews. The data analysis resulted in the formation of a limited number of models concerning the distribution and role of ozone in the atmosphere, the depletion process, and the consequences of ozone depletion. Identifies five target…

  1. CONTRIBUTION TO INDOOR OZONE LEVELS OF AN OZONE GENERATOR

    EPA Science Inventory

    This report gives results of a study of a commonly used commercially available ozone generator, undertaken to determine its impact on indoor ozone levels. xperiment were conducted in a typical mechanically ventilated office and in a test house. he generated ozone and the in-room ...

  2. Ozone Minimums, 1979 to 2013

    NASA Video Gallery

    Minimum concentration of ozone in the southern hemisphere for each year from 1979-2013 (there is no data from 1995). Each image is the day of the year with the lowest concentration of ozone. A grap...

  3. An automated ozone photometer

    NASA Technical Reports Server (NTRS)

    Lavelle, Joseph R.

    1988-01-01

    A photometer capable of automatically measuring ozone concentration data to very high resolution during scientific research flights in the Earth's atmosphere was developed at NASA Ames Research Center. This instrument was recently deployed to study the ozone hole over Antarctica. Ozone is detected by absorbing 253.7-nm radiation from an ultraviolet lamp which shines through the sample of air and impinges on a vacuum phototube. A lower output from the phototube indicates more ozone present in the air sample. The photometer employs a CMOS Z80 microprocessor with an STD bus system for experiment control, data collection, and storage. Data are collected and stored in nonvolatile memory for experiments lasting up to 8 hr. Data are downloaded to a portable ground-support computer and processed after the aircraft lands. An independent single-board computer in the STD bus also calculates ozone concentration in real time with less resolution than the CMOS Z80 system, and sends this value to a cockpit meter to aid the pilot in navigation.

  4. High Concentration of Surface Ozone Observed along the Khumbu Valley Nepal April 2007

    NASA Astrophysics Data System (ADS)

    Semple, J.; Moore, K.

    2009-12-01

    Increasing air pollution in Southeast Asia has the potential for dramatic impacts on the population and climate in relatively pristine regions such as the Himalaya. Recent measurements near Mount Everest indicate the presence of elevated levels of ozone at elevations from 5000m to 9000m that are the result of both the long-range transport of tropospheric pollutants from Southeast Asia as well as the descent of ozone-rich stratospheric air. Here we report on the first surface ozone concentration transect in the Mount Everest region. The data collected at elevations from 2900m to 5200m indicate an increase in concentration with height as well as 8-hour average exposures in excess of 140ppb. Satellite data and meteorological diagnostics suggest a stratospheric source for the high levels observed. The majority of values observed exceed guidelines for human exposure and therefore are of a magnitude to suggest that they are of physiological relevance. Potential vorticity (PVU-shading and contours) and horizontal wind (vectors-m/s) from the ERA-I Reanalysis on the 330K potential temperature surface at 06 UTC (approximately noon local time) on April 12 2007 showing the tropopause fold that resulted in the high surface ozone concentration observed along the Khumbu Valley near Mount Everest. The 1 PVU contour is indicated by the thin black line. The Tibetan Plateau is indicated as is the location of Mount Everest by the ‘+’.

  5. Ames ER-2 ozone measurements

    NASA Technical Reports Server (NTRS)

    Pearson, R., Jr.; Vedder, James F.; Starr, W. L.

    1990-01-01

    The objective of this research is to study ozone (O3) in the stratosphere. Measurements of the ozone mixing ratio at 1 s intervals are obtained with an ultraviolet photometer which flies on the ER-2 aircraft. The photometer determines the amount of ozone in air by measuring the transmission of ultraviolet light through a fixed path with and without ambient O3 present.

  6. Ozone depletion by hydrofluorocarbons

    NASA Astrophysics Data System (ADS)

    Hurwitz, Margaret M.; Fleming, Eric L.; Newman, Paul A.; Li, Feng; Mlawer, Eli; Cady-Pereira, Karen; Bailey, Roshelle

    2015-10-01

    Atmospheric concentrations of hydrofluorocarbons (HFCs) are projected to increase considerably in the coming decades. Chemistry climate model simulations forced by current projections show that HFCs will impact the global atmosphere increasingly through 2050. As strong radiative forcers, HFCs increase tropospheric and stratospheric temperatures, thereby enhancing ozone-destroying catalytic cycles and modifying the atmospheric circulation. These changes lead to a weak depletion of stratospheric ozone. Simulations with the NASA Goddard Space Flight Center 2-D model show that HFC-125 is the most important contributor to HFC-related atmospheric change in 2050; its effects are comparable to the combined impacts of HFC-23, HFC-32, HFC-134a, and HFC-143a. Incorporating the interactions between chemistry, radiation, and dynamics, ozone depletion potentials (ODPs) for HFCs range from 0.39 × 10-3 to 30.0 × 10-3, approximately 100 times larger than previous ODP estimates which were based solely on chemical effects.

  7. SAGE II Ozone Analysis

    NASA Technical Reports Server (NTRS)

    Cunnold, Derek; Wang, Ray

    2002-01-01

    Publications from 1999-2002 describing research funded by the SAGE II contract to Dr. Cunnold and Dr. Wang are listed below. Our most recent accomplishments include a detailed analysis of the quality of SAGE II, v6.1, ozone measurements below 20 km altitude (Wang et al., 2002 and Kar et al., 2002) and an analysis of the consistency between SAGE upper stratospheric ozone trends and model predictions with emphasis on hemispheric asymmetry (Li et al., 2001). Abstracts of the 11 papers are attached.

  8. Normally Expected Aberrations in the 8-hour Dynamic EKG

    NASA Technical Reports Server (NTRS)

    Fleck, R. L.; Arnoldi, L. B.; Townsend, J. C.; Tonesk, X.

    1970-01-01

    The establishment of norms for interpreting long term dynamic electrocardiograms is attempted by correlating a completely disease symptom and cardiac risk factor free sample with a non-pure sample in the direction of normality on various variables. Out of a population of 362 subjects exposed to dynamic electrocardiogram testing, a discrimination between normals and abnormals in terms of traditional risk factors was observed. The two groups differed significantly on the following variables: cholesterol, smoking, systolic blood pressure, white blood count, fasting blood sugar, uric acid, resting EKG, year of birth, and coronary insufficiency.

  9. Tropospheric ozone in the vicinity of the ozone hole - 1987 Airborne Antarctic Ozone Experiment

    NASA Technical Reports Server (NTRS)

    Gregory, Gerald L.; Warren, Linda S.; Hypes, Warren D.; Tuck, Adrian F.; Kelly, Kenneth K.; Krueger, Arlin J.

    1989-01-01

    Results are presented on ozone measurements in the upper troposphere/lower stratosphere over Antarctica, obtained by NASA DC-8 aircraft during the August/September 1987 Airborne Antarctic Ozone Experiment. The ozone mixing ratios as high as several hundred ppbv were measured, but in all cases these ratios were observed in pockets of upper atmospheric air, both in the vicinity of and away from the location of the ozone hole. The background ozone values in the surrounding troposphere were typically in the range of 20-50 ppbv. Correlation of tropospheric ozone observations with the boundaries of the ozone hole differed in the course of the experiment. During the August 28 - September 2 flights, encounters with ozone-rich air were limited, and the background tropospheric ozone appeared to decrease beneath the hole. For the later flights, and as the ozone hole deepened, the ozone-rich air was frequently observed in the vicinity of the hole, and the average ozone values at the flight altitude were frequently higher than the background values.

  10. Precision ozone vapor pressure measurements

    NASA Technical Reports Server (NTRS)

    Hanson, D.; Mauersberger, K.

    1985-01-01

    The vapor pressure above liquid ozone has been measured with a high accuracy over a temperature range of 85 to 95 K. At the boiling point of liquid argon (87.3 K) an ozone vapor pressure of 0.0403 Torr was obtained with an accuracy of + or - 0.7 percent. A least square fit of the data provided the Clausius-Clapeyron equation for liquid ozone; a latent heat of 82.7 cal/g was calculated. High-precision vapor pressure data are expected to aid research in atmospheric ozone measurements and in many laboratory ozone studies such as measurements of cross sections and reaction rates.

  11. Karlson ozone sterilizer. Final report

    SciTech Connect

    Karlson, E.

    1984-05-07

    The authors have a functional sterilization system employing ozone as a sterilization agent. This final report covers the work that led to the first medical sterilizer using ozone as the sterilizing agent. The specifications and the final design were set by hospital operating room personnel and public safety standards. Work on kill tests using bacteria, viruses and fungi determined the necessary time and concentration of ozone necessary for sterilization. These data were used in the Karlson Ozone Sterilizer to determine the length of the steps of the operating cycle and the concentration of ozone to be used. 27 references.

  12. Total Ozone Prediction: Stratospheric Dynamics

    NASA Technical Reports Server (NTRS)

    Jackman, Charles H.; Kawa, S. Ramdy; Douglass, Anne R.

    2003-01-01

    The correct prediction of total ozone as a function of latitude and season is extremely important for global models. This exercise tests the ability of a particular model to simulate ozone. The ozone production (P) and loss (L) will be specified from a well- established global model and will be used in all GCMs for subsequent prediction of ozone. This is the "B-3 Constrained Run" from M&MII. The exercise mostly tests a model stratospheric dynamics in the prediction of total ozone. The GCM predictions will be compared and contrasted with TOMS measurements.

  13. Source Contribution of Volatile Organic Compounds to Ozone Formation in Southeast Texas

    NASA Astrophysics Data System (ADS)

    Ying, Q.

    2009-12-01

    The Houston-Galveston-Brazoria (HGB) and Beaumont-Port Arthur (BPA) areas in the southeast Texas are respectively in severe and moderate non-attainment status for the National Ambient Air Quality Standards for ozone (O3). In order to design effective emission control strategies to improve ozone air quality, it is necessary to understand the contribution of volatile organic compounds (VOCs) from different sources to O3 formation. In this study, a source-oriented SAPRC-99 gas phase photochemical mechanism was developed and incorporated into the Community Multiscale Air Quality (CMAQ) model to determine the contribution of volatile organic compounds (VOCs) from different sources to the predicted net ozone formation rate in southeast Texas during the Texas Air Quality Study (TexAQS) from 16 August - 6 September 2000. Contribution from eight different sources: biogenic, diesel engines, highway gasoline vehicles, off-highway gasoline engines, solvent utilization, petroleum industry, other industries and wildfire were resolved. This is the first time that the regional source contribution of VOCs to O3 formation has been quantified using a three-dimensional source oriented modeling approach in southeast Texas. Regional source contribution analysis indicates that the VOCs emitted from petrochemical industries are responsible to a large amount of O3 formation in the HGB and BPA area. The peak O3 formation rate due to petroleum industry and other industries combined is ~8 ppb hr(-1) in early afternoon hours, which rivals the O3 formation rate due to biogenic sources (~ 9 ppb hr(-1)). Gasoline vehicles also contribute significantly to the ozone formation, with a maximum contribution of ~3.5 ppb hr(-1). The spatial coverage of vehicle sources is larger that of industrial sources. Solvent utilization contributes ~1.2 ppb hr(-1) and has similar spatial coverage as gasoline vehicle sources. VOC emissions from reciprocating engines powered by natural gas are the most significant

  14. Assimilation of Satellite Ozone Observations

    NASA Technical Reports Server (NTRS)

    Stajner, I.; Winslow, N.; Wargan, K.; Hayashi, H.; Pawson, S.; Rood, R.

    2003-01-01

    This talk will discuss assimilation of ozone data from satellite-borne instruments. Satellite observations of ozone total columns and profiles have been measured by a series of Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet (SBUV) instruments, and more recently by the Global Ozone Monitoring Experiment. Additional profile data are provided by instruments on NASA's Upper Atmosphere Research Satellite and by occultation instruments on other platforms. Instruments on Envisat' and future EOS Aura satellite will supply even more comprehensive data about the ozone distribution. Satellite data contain a wealth of information, but they do not provide synoptic global maps of ozone fields. These maps can be obtained through assimilation of satellite data into global chemistry and transport models. In the ozone system at NASA's Data Assimilation Office (DAO) any combination of TOMS, SBUV, and Microwave Limb sounder (MLS) data can be assimilated. We found that the addition of MLS to SBUV and TOMS data in the system helps to constrain the ozone distribution, especially in the polar night region and in the tropics. The assimilated ozone distribution in the troposphere and lower stratosphere is sensitive also to finer changes in the SBUV and TOMS data selection and to changes in error covariance models. All results are established by comparisons of assimilated ozone with independent profiles from ozone sondes and occultation instruments.

  15. The Ozone Show.

    ERIC Educational Resources Information Center

    Mathieu, Aaron

    2000-01-01

    Uses a talk show activity for a final assessment tool for students to debate about the ozone hole. Students are assessed on five areas: (1) cooperative learning; (2) the written component; (3) content; (4) self-evaluation; and (5) peer evaluation. (SAH)

  16. Ozone decomposing filter

    DOEpatents

    Simandl, Ronald F.; Brown, John D.; Whinnery, Jr., LeRoy L.

    1999-01-01

    In an improved ozone decomposing air filter carbon fibers are held together with a carbonized binder in a perforated structure. The structure is made by combining rayon fibers with gelatin, forming the mixture in a mold, freeze-drying, and vacuum baking.

  17. Ozone and temperature trends

    NASA Technical Reports Server (NTRS)

    Labitzke, K.; Miller, A. J.; Angell, J.; Deluisi, J.; Frederick, J.; Logan, J.; Mateer, C.; Naujokat, B.; Reinsel, G.; Tiao, G.

    1985-01-01

    The measurement of temporal changes in ozone and temperature are discussed. The data are examined within the context of natural atmospheric variability and data problems. The results are compared to numerical model calculations. The major issues are defined in terms of goal achievement. Each parameter is considered in terms of instrument type, long term effects, and altitude.

  18. Ozone decomposing filter

    SciTech Connect

    Simandl, R.F.; Brown, J.D.; Whinnery, L.L. Jr.

    1999-11-02

    In an improved ozone decomposing air filter carbon fibers are held together with a carbonized binder in a perforated structure. The structure is made by combining rayon fibers with gelatin, forming the mixture in a mold, freeze-drying, and vacuum baking.

  19. Ozone Layer Educator's Guide.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC.

    This guide has been developed through a collaborative effort involving the U.S. Environmental Protection Agency (EPA), the National Oceanic and Atmospheric Administration (NOAA), and the National Aeronautics and Space Administration (NASA). It is part of an ongoing commitment to ensure that the results of scientific research on ozone depletion are…

  20. Dobson ozone spectrophotometer modification.

    NASA Technical Reports Server (NTRS)

    Komhyr, W. D.; Grass, R. D.

    1972-01-01

    Description of a modified version of the Dobson ozone spectrophotometer in which several outdated electronic design features have been replaced by circuitry embodying more modern design concepts. The resulting improvement in performance characteristics has been obtained without changing the principle of operation of the original instrument.

  1. Revisiting Antarctic Ozone Depletion

    NASA Astrophysics Data System (ADS)

    Grooß, Jens-Uwe; Tritscher, Ines; Müller, Rolf

    2015-04-01

    Antarctic ozone depletion is known for almost three decades and it has been well settled that it is caused by chlorine catalysed ozone depletion inside the polar vortex. However, there are still some details, which need to be clarified. In particular, there is a current debate on the relative importance of liquid aerosol and crystalline NAT and ice particles for chlorine activation. Particles have a threefold impact on polar chlorine chemistry, temporary removal of HNO3 from the gas-phase (uptake), permanent removal of HNO3 from the atmosphere (denitrification), and chlorine activation through heterogeneous reactions. We have performed simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) employing a recently developed algorithm for saturation-dependent NAT nucleation for the Antarctic winters 2011 and 2012. The simulation results are compared with different satellite observations. With the help of these simulations, we investigate the role of the different processes responsible for chlorine activation and ozone depletion. Especially the sensitivity with respect to the particle type has been investigated. If temperatures are artificially forced to only allow cold binary liquid aerosol, the simulation still shows significant chlorine activation and ozone depletion. The results of the 3-D Chemical Transport Model CLaMS simulations differ from purely Lagrangian longtime trajectory box model simulations which indicates the importance of mixing processes.

  2. Overview of ozone human exposure and health risk analyses used in the U.S. EPA's review of the ozone air quality standard.

    SciTech Connect

    Whitfield, R. G.

    1999-03-04

    This paper presents an overview of the ozone human exposure and health risk analyses developed under sponsorship of the U.S. Environmental Protection Agency (EPA). These analyses are being used in the current review of the national ambient air quality standards (NAAQS) for ozone. The analyses consist of three principal steps: (1) estimating short-term ozone exposure for particular populations (exposure model); (2) estimating population response to exposures or concentrations (exposure-response or concentration-response models); and (3) integrating concentrations or exposure with concentration-response or exposure-response models to produce overall risk estimates (risk model). The exposure model, called the probabilistic NAAQS exposure model for ozone (pNEM/03), incorporates the following factors: hourly ambient ozone concentrations; spatial distribution of concentrations; ventilation state of individuals at time of exposure; and movement of people through various microenvironments (e.g., outdoors, indoors, inside a vehicle) of varying air quality. Exposure estimates are represented by probability distributions. Exposure-response relationships have been developed for several respiratory symptom and lung function health effects, based on the results of controlled human exposure studies. These relationships also are probabilistic and reflect uncertainties associated with sample size and variability of response among subjects. The analyses also provide estimates of excess hospital admissions in the New York City area based on results from an epidemiology study. Overall risk results for selected health endpoints and recently analyzed air quality scenarios associated with alternative 8-hour NAAQS and the current 1-hour standard for outdoor children are used to illustrate application of the methodology.

  3. Field Testing of New Interference-Free Ambient Ozone Monitors

    NASA Astrophysics Data System (ADS)

    Ollison, W. M.; Capel, J.; Crow, W.; Johnson, T.; Spicer, C. W.

    2013-05-01

    Multibillion-dollar strategies control ambient air ozone (O3) levels in the U.S. so it is essential that the O3 measurements made for developing state implementation plans, assessing population risks, and determining compliance with regulations be accurate. The predominant U.S. regulatory method employed to monitor ambient O3 is ultraviolet (254 nm) photometry and many previous studies have demonstrated positive interferences associated with this technology. We evaluate two new humidity-controlled commercial instruments - a 2B Technology Model 211 ultraviolet O3 photometer that replaces its conventional MnO2 scrubber with gas-phase NO titration and a Teledyne-API Model 265E NO-O3 chemiluminescence monitor - both designed to minimize the aromatic organic, mercury, and water vapor interferences common to O3 photometers. New units were paired with conventional photometers sampling indoor, outdoor, and in-vehicle environments where populations spend most of their time. Overall, during the fixed-site monitor comparisons in Houston, TX, the three instruments were highly correlated (r2 ≥ 0.99) with regression slopes of 1.00 ± 0.01, and O3 averaged over the study period agreed within 1 ppb; however, U.S. O3 standard compliance depends on fourth highest annual daily maximum 8-hour O3 values, so urban monitors must measure accurately during typically hot, humid, and stagnant O3-conducive day conditions. Conventional photometers reported the highest values for the four highest 8-hour daily maxima during our three month late summer test period, with 8-hour average differences between the new and conventional monitors ranging up to 4 ppb. In paired 10-minute average sampling with a Model 211 in Durham, NC, conventional photometers generally exhibited modest positive interference bias (under 5 ppb) in 176 sampled residences, shops, malls, restaurants, offices, parks, roadways, and vehicles; however, in six percent of our samples indoor differences exceeded 10 ppb and in two

  4. Tropospheric ozone in the vicinity of the ozone hole: 1987 Airborne Antarctic Ozone Experiment

    SciTech Connect

    Gregory, G.L.; Warren, L.S. ); Hypes, W.D. ); Tuck, A.F.; Kelly, K.K. ); Krueger, A.J. )

    1989-11-30

    Tropospheric ozone measurements over Antarctica aboard the NASA DC-8 aircraft are summarized. As part of the August/September 1987 Airborne Antarctic Ozone Experiment, the aircraft flew 13 missions covering a latitude of 53{degree}-90{degree}S, at altitudes to 13 km. Ozone mixing ratios as high as several hundred parts per billion by volume (ppbv) were measured, but in all cases these ratios were observed in pockets or patches of upper atmospheric air. These pockets were observed both in the vicinity of and away from the location of the ozone hole. At times, and as a result of these pockets, the ozone levels at the flight altitude of the aircraft, as averaged beneath the boundaries of the stratospheric ozone hole, were 2-3 times higher than background tropospheric values. The data suggest that the ozone-rich air seldom penetrated below about 9-km altitude. Background ozone values in the surrounding troposphere were typically in the range of 20-50 ppbv. Correlation of tropospheric ozone observations with the boundaries of the ozone hole differed during the experiment. During the early flights (August 28 through September 2), encounters with ozone-rich air were limited and background tropospheric ozone (at the flight altitude) appeared to decrease beneath the hole. For many of the later flights, and as the hole deepened, the reverse was noted, in that ozone-rich air was frequently observed in the vicinity of the hole and, as noted earlier, average ozone at the flight altitude was frequently higher than background values.

  5. 16 CFR 260.11 - Ozone-safe and ozone-friendly claims.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... friendly to, the ozone layer or the atmosphere. Example 1: A product is labeled “ozone-friendly.” The claim... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Ozone-safe and ozone-friendly claims. 260.11... THE USE OF ENVIRONMENTAL MARKETING CLAIMS § 260.11 Ozone-safe and ozone-friendly claims. It...

  6. 16 CFR 260.11 - Ozone-safe and ozone-friendly claims.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... friendly to, the ozone layer or the atmosphere. Example 1: A product is labeled “ozone-friendly.” The claim... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Ozone-safe and ozone-friendly claims. 260.11... THE USE OF ENVIRONMENTAL MARKETING CLAIMS § 260.11 Ozone-safe and ozone-friendly claims. It...

  7. Solving the Tulsa ozone problem

    SciTech Connect

    Wagner, K.K.; Wilson, J.D.; Gibeau, E.

    1998-12-31

    Local governments and interested parties in Tulsa, Oklahoma are planning actions to keep Tulsa in compliance with the ozone ambient air quality standard. Based on recent data Tulsa exceeds the new eight hour average national ambient air quality standard for ozone and occasionally exceeds the previous one hour standard. Currently, Tulsa is in attainment of the former one-hour ozone standard. The first planning step is to integrate the existing information about Tulsa`s ozone problem. Prior studies of Tulsa ozone are reviewed. Tulsa`s recent air quality and meteorological monitoring are evaluated. Emission inventory estimates are assessed. Factors identified with Tulsa`s ozone problem are the transport of ozone and precursor gases, a possible role for biogenic emissions, and a simplistic ozone forecasting method. The integration of information found that current air quality and meteorological monitoring is meager. Observations of volatile organic compounds and NO{sub y} are absent. Prior intensive studies in 1977 and 1985 are more than ten years old and lack relevance to today`s problem. Emission inventory estimates are scarce and uncertain. The current knowledge base was judged inadequate to properly characterize the present ozone problem. Actions are recommended to enlarge the information base to address Tulsa`s ozone problem.

  8. CFCS and the ozone layer.

    PubMed

    Hayman, G D

    1997-05-01

    Ozone is an important constituent of the atmosphere. Ozone forms a distinct layer in the lower stratosphere known as the ozone layer. The ozone layer acts as a fragile shield because it protects man and other life forms from exposure to harmful short-wavelength ultraviolet (UV) radiation. The agents, particularly chemical, which affect the amount of ozone present in the atmosphere have been a source of concern for more than 20 years. This has been reinforced by the dramatic decline of stratospheric ozone levels first measured in Antarctica and now apparent worldwide. The combination of routine measurements of ozone depletion, careful laboratory studies and mathematical modelling of ozone in the atmosphere, has demonstrated that the reactive fragments produced when chlorofluorocarbons (CFCs), halons and other halogenated compounds break down in the stratosphere are responsible for the ozone loss. As CFCs have widespread and sometimes apparently essential uses in modern society, there has been an intense effort to develop safe, effective replacements which have a negligible or much smaller impact on the environment. The Montreal Protocol, signed by over 140 nations, has been implemented to control and phase out the chemical compounds responsible for ozone loss. PMID:9519506

  9. Precision ozone calibration system based on vapor pressures of ozone

    NASA Technical Reports Server (NTRS)

    Mauersberger, K.; Hanson, D.; Morton, J.

    1987-01-01

    A precision ozone calibration system for stratospheric research has been developed and evaluated. Vapor pressures above solid ozone are mixed with a carrier gas (N2) to produce stratospheric ozone mixing ratios at total pressures of 1 to cover 20 torr. The uncertainty in the ozone mixing ratios is approximately + or - 1.5 percent, the stability of ozone is + or - 0.3 percent. Experiments to be calibrated may sample the gas mixture over a wide range of flow rates; the maximum throughput of gas with corrections of less than 1 percent to ozone is about 200 torr 1/min. A mass spectrometer system continuously monitors the purity and stability of the N2-O3 gas mixture.

  10. [Ozone source apportionment at urban area during a typical photochemical pollution episode in the summer of 2013 in the Yangtze River Delta].

    PubMed

    Li, Hao; Li, Li; Huang, Cheng; An, Jing-yu; Yan, Ru-sha; Huang, Hai-ying; Wang, Yang-jun; Lu, Qing; Wang, Qian; Lou, Sheng-rong; Wang, Hong-li; Zhou, Min; Tao, Shi-kang; Qiao, Li-ping; Chen, Ming-hua

    2015-01-01

    With the fast development of urbanization, industrialization and mobilization, the air pollutant emissions with photochemical reactivity become more obvious, causing a severe photochemical pollution with the characteristics of high ozone concentration. However, the ozone source identification is very complicated due to the high non linearity between ozone and its precursors. Thus, ways to reduce ozone is still not clear. A high ozone pollution episode occurred during July, 2013, which lasted for a long period, with large influence area and high intensity. In this paper, we selected this episode to do a case study with the application of ozone source apportionment technology(OSAT) coupled within the CAMx air quality model. In this study, 4 source regions(including Shanghai, north Zhejiang, South Jiangsu and long range transport), 7 source categories (including power plants, industrial process, industrial boilers and kilns, residential, mobile source, volatile source and biogenic emissions) are analyzed to study their contributions to surface O3 in Shanghai, Suzhou and Zhejiang. Results indicate that long range transport contribution to the surface ozone in the YRD is around 20 x 10(-9) - 40 x 10(-9) (volume fraction). The O3 concentrations can increased to 40 x 10(-9) - 100 x 10(-9) (volume fraction) due to precursors emissions in Shanghai, Jiangsu and Zhejiang. As for the regional contribution to 8 hour ozone, long range transport constitutes 42.79% +/- 10.17%, 48.57% +/- 9.97% and 60.13% +/- 7.11% of the surface ozone in Shanghai, Suzhou and Hangzhou, respectively. Regarding the high O3 in Shanghai, local contribution is 28.94% +/- 8.49%, north Zhejiang constitutes 19.83% +/- 10.55%. As for surface O3 in Suzhou, the contribution from south Jiangsu is 26.41% +/- 6.80%. Regarding the surface O3 in Hangzhou, the major regional contributor is north Zhejiang (29.56% +/- 8.33%). Contributions from the long range transport to the daily maximum O3 concentrations are

  11. Alternative ozone metrics and daily mortality in Suzhou: the China Air Pollution and Health Effects Study (CAPES).

    PubMed

    Yang, Chunxue; Yang, Haibing; Guo, Shu; Wang, Zongshuang; Xu, Xiaohui; Duan, Xiaoli; Kan, Haidong

    2012-06-01

    Controversy remains regarding the relationship between various metrics of ozone (O(3)) and mortality. In China, the largest developing country, there have been few studies investigating the acute effect of O(3) on death. We used three exposure metrics of O(3) (1-hour maximum, maximum 8-hour average and 24-hour average) to examine its short-term association with daily mortality in Suzhou, China. We used a Generalized Additive Model (GAM) with penalized splines to analyze the mortality, O(3), and covariate data. We examined the association by season, age group, sex and educational level. We found that the current level of O(3) in Suzhou is associated with death rates from all causes and cardiovascular diseases. Among various metrics of O(3), maximum 8-hour average and 1-hour maximum concentrations seem to be more strongly associated with increased mortality rate compared to 24-hour average concentrations. Using maximum 8-hour average, an inter-quartile range increase of 2-day average O(3) (lag 01) corresponds to 2.15% (95%CI, 0.36 to 3.93), 4.47% (95%CI, 1.43 to 7.51), -1.85% (95%CI, -6.91 to 3.22) increase in all-cause, cardiovascular, and respiratory mortality, respectively. The associations between O(3) and daily mortality appeared to be more evident in the cool season than in the warm season. In conclusion, maximum 8-hour average and 1-hour maximum concentrations of O(3) are associated with daily mortality in Suzhou. Our analyses strengthen the rationale for further limiting levels of O(3) pollution in the city. PMID:22521098

  12. Balloonborne ozone and aerosol measurements in the antarctic ozone hole

    SciTech Connect

    Hofmann, D.J.; Harder, J.W.; Rolf, S.R.; Rosen, J.M. )

    1987-01-01

    The National Ozone Expedition (NOZE) was mounted in 1986 using winter fly-in flights to McMurdo Station in August, which is approximately the time the ozone reduction begins. The University of Wyoming Atmospheric Physics group participated in this expedition through balloonborne measurements of the vertical distribution of ozone and aerosol particles. Between 24 August and 6 November, 33 ozone soundings, 6 aerosol sounding, and 3 condensation nuclei soundings were conducted using polyethylene balloons which were able to penetrate the cold (< {minus}80C) antarctic stratosphere. The authors summarize these results here.

  13. Ozone and ozone byproducts in the cabins of commercial aircraft.

    PubMed

    Weisel, Clifford; Weschler, Charles J; Mohan, Kris; Vallarino, Jose; Spengler, John D

    2013-05-01

    The aircraft cabin represents a unique indoor environment due to its high surface-to-volume ratio, high occupant density, and the potential for high ozone concentrations at cruising altitudes. Ozone was continuously measured and air was sampled on sorbent traps, targeting carbonyl compounds, on 52 transcontinental U.S. or international flights between 2008 and 2010. The sampling was predominantly on planes that did not have ozone scrubbers (catalytic converters). Peak ozone levels on aircraft without catalytic convertors exceeded 100 ppb, with some flights having periods of more than an hour when the ozone levels were >75 ppb. Ozone was greatly reduced on relatively new aircraft with catalytic convertors, but ozone levels on two flights whose aircraft had older convertors were similar to those on planes without catalytic convertors. Hexanal, heptanal, octanal, nonanal, decanal, and 6-methyl-5-hepten-2-one (6-MHO) were detected in the aircraft cabin at sub- to low ppb levels. Linear regression models that included the log transformed mean ozone concentration, percent occupancy, and plane type were statistically significant and explained between 18 and 25% of the variance in the mixing ratio of these carbonyls. Occupancy was also a significant factor for 6-MHO, but not the linear aldehydes, consistent with 6-MHO's formation from the reaction between ozone and squalene, which is present in human skin oils. PMID:23517299

  14. The role of refinery flaring events and bay breezes on a high surface ozone episode during the Houston, Texas DISCOVER-AQ field campaign

    NASA Astrophysics Data System (ADS)

    Loughner, C.; Follette-Cook, M. B.; Fried, A.; Pickering, K. E.

    2015-12-01

    The highest observed surface ozone concentrations in the Houston metropolitan area in 2013 occurred on September 25, which coincided with the Texas DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) field campaign. Surface ozone was elevated throughout the Houston metropolitan area with maximum 8-hour average ozone peaking along the western shore of Galveston Bay, reaching 124 ppbv, almost 50 ppbv above the current EPA standard of 75 ppbv. The NASA P-3B aircraft observed plumes from refinery flares west and northwest of Galveston Bay that were transported over the water. Continental air pollution from the north was transported into the Houston metropolitan area where it mixed with locally generated emissions. A bay breeze circulation formed causing pollutants that were transported out over the water in the morning to recirculate back inland where they mixed with freshly emitted pollution near the bay breeze convergence zone. The highest surface ozone concentrations were reported near the bay breeze front. This ozone episode will be presented using measurements made during the DISCOVER-AQ field campaign and a CMAQ model simulation with integrated source apportionment, which tracks the contribution of emissions source groups and regions on ozone concentrations.

  15. Ozone Risk Assessment Utilities

    1999-08-10

    ORAMUS is a user-friendly, menu-driven software system that calculates and displays user-selected risk estimates for health effects attributable to short-term exposure to tropospheric ozone. Inputs to the risk assessment are estimates of exposure to ozone and exposure-response relationships to produce overall risk estimates in the form of probability distributions. Three fundamental models are included: headcount risk, benchmark risk, and hospital admissions. Exposure-response relationships are based on results of controlled human exposure studies. Exposure estimates aremore » based on the EPA''s probabilistic national ambient air quality standards (NAAQS) exposure model, pNEM/Osub3, which simulates air quality associated with attainment of alternative NAAQS. Using ORAMUS, risk results for 27 air quality scenarios, air quality in 9 urban areas, 33 health endpoints, and 4 chronic health endpoints can be calculated.« less

  16. The Antarctic ozone hole

    SciTech Connect

    Stolarski, R.S.

    1988-01-01

    Because the effects are so serious, many investigators have been racing to determine the causes of the hole which develops each southern spring within the polar vortex, an isolated air mass that circulates around the South Pole during a large part of the year. This paper reviews two of the foremost theories for this ozone hole. Mechanisms of the pollution theory, which proposes that the cause is chlorofluorocarbons and nitrogen oxides in the atmosphere, are reviewed. The second theory proposes a natural shift in the air movements that transport ozone-rich air into the polar stratosphere during the southern spring as the cause. Current data suggest both theories are correct, but data are considered inconclusive.

  17. Ozonated olive oils and the troubles.

    PubMed

    Uysal, Bulent

    2014-01-01

    One of the commonly used methods for ozone therapy is ozonated oils. Most prominent type of used oils is extra virgin olive oil. But still, each type of unsaturated oils may be used for ozonation. There are a lot of wrong knowledge on the internet about ozonated oils and its use as well. Just like other ozone therapy studies, also the studies about ozone oils are inadequate to avoid incorrect knowledge. Current data about ozone oil and its benefits are produced by supplier who oversees financial interests and make misinformation. Despite the rapidly increasing ozone oil sales through the internet, its quality and efficacy is still controversial. Dozens of companies and web sites may be easily found to buy ozonated oil. But, very few of these products are reliable, and contain sufficiently ozonated oil. This article aimed to introduce the troubles about ozonated oils and so to inform ozonated oil users. PMID:26401346

  18. Ozone, Air Quality, and Asthma (For Parents)

    MedlinePlus

    ... found in both the Earth's upper and lower atmospheres. The protective ozone in the upper atmosphere is very different from the harmful ozone in the lower atmosphere. Ozone that exists naturally 10 to 30 miles ( ...

  19. Ozonated olive oils and the troubles

    PubMed Central

    Uysal, Bulent

    2014-01-01

    One of the commonly used methods for ozone therapy is ozonated oils. Most prominent type of used oils is extra virgin olive oil. But still, each type of unsaturated oils may be used for ozonation. There are a lot of wrong knowledge on the internet about ozonated oils and its use as well. Just like other ozone therapy studies, also the studies about ozone oils are inadequate to avoid incorrect knowledge. Current data about ozone oil and its benefits are produced by supplier who oversees financial interests and make misinformation. Despite the rapidly increasing ozone oil sales through the internet, its quality and efficacy is still controversial. Dozens of companies and web sites may be easily found to buy ozonated oil. But, very few of these products are reliable, and contain sufficiently ozonated oil. This article aimed to introduce the troubles about ozonated oils and so to inform ozonated oil users. PMID:26401346

  20. Protecting beans from ozone

    SciTech Connect

    Pierce, R.

    1983-03-01

    A chemical treatment to protect navy beans from ozone damage increased yields by an average of more than 20% in 3 years of tests. An experimental antioxidant chemical, EDU, made by the DuPont company was tested as soil applications and sprays on several varieties and under a variety of soil and planting conditions. The average yield increases were between 16 and 24%. Chemical treatment also increased snap bean pod production by 12%.

  1. Another deep Antarctic ozone hole

    SciTech Connect

    Kerr, R.A.

    1990-10-19

    Again in 1990, drastic depletion of stratospheric ozone over the South Pole has been measured, in August 140 Dobson units, far below the 220 Dobson units typically seen over Antarctica. This extensive destruction of ozone is determined to be brought about by sunshine acting in combination with the chlorine released from chlorofluorohydrocarbons (CFCs) by icy stratospheric clouds. It is concluded that CFC concentrations have now reached a level that will almost totally destroy the ozone in the lower stratosphere in most years.

  2. Ozone transport commission developments

    SciTech Connect

    Joyce, K.M.

    1995-08-01

    On September 27, 1994, the states of the Ozone Transport Commission (OTC) signed an important memorandum of understanding (MOU) agreeing to develop a regional strategy for controlling stationary sources of nitrogen oxide emissions. Specifically, the states of the Ozone Transport Region, OTR, agreed to propose regulations for the control of NOx emissions from boilers and other indirect heat exchangers with a maximum gross heat input rate of at least 250 million BTU per hour. The Ozone Transport Region was divided into Inner, Outer and Northern Zones. States in the Outer Zone agreed to reduce NOx emissions by 55%. States in the Inner Zone agreed to reduce NOx emissions 65%. Facilities in both zones have the option to emit NOx at a rate no greater than 0.2 pounds per million Btu by May 1, 1999. This option provides fairness for the gas-fired plants which already have relatively low NOx emissions. Additionally, States in the Inner and Outer Zones agreed to reduce their NOx emissions by 75% or to emit NOx at a rate no greater than 0.15 pounds per million BTU by May 1, 2003. The Northern Zone States agree to reduce their rate of NOx emissions by 55% from base year levels by May 1, 2003, or to emit NOx at a rate no greater than 0.2 pounds per million BTU. As part of this MOU, States also agreed to develop a regionwide trading mechanism to provide a cost-effective mechanism for implementing the reductions.

  3. Ozone measurement systems improvements studies

    NASA Technical Reports Server (NTRS)

    Thomas, R. W.; Guard, K.; Holland, A. C.; Spurling, J. F.

    1974-01-01

    Results are summarized of an initial study of techniques for measuring atmospheric ozone, carried out as the first phase of a program to improve ozone measurement techniques. The study concentrated on two measurement systems, the electro chemical cell (ECC) ozonesonde and the Dobson ozone spectrophotometer, and consisted of two tasks. The first task consisted of error modeling and system error analysis of the two measurement systems. Under the second task a Monte-Carlo model of the Dobson ozone measurement technique was developed and programmed for computer operation.

  4. Summary of the Federal Advisory Committee Act (FACA) subcommittee for ozone, particulate matter and regional haze implementation programs discussions and recommendations

    SciTech Connect

    Battye, R.E.

    1998-12-31

    The US Environmental Protection Agency created the Federal Advisory Committee Act (FACA) Subcommittee for Ozone, Particulate Matter, and Regional Haze Implementation Programs to offer advice on multiple issues involved in implementing new, more stringent national standards for ozone and particulate matter, and a new regional haze rule. The Subcommittee convened in September 1995 and the final full Subcommittee meeting was held in December 1997. During this period the Subcommittee discussed over 28 issue papers dealing with the implementation of new and revised national ambient air quality standards. The issues generally break into six categories. The first category of issues is the development of appropriate control regions. The Subcommittee recognized the limitations in the current nonattainment approach and proposed an alternative construct that would deal with transported air pollution. The second category are planning and implementation issues which includes the institutional mechanisms that are needed to address transport across state boundaries, air quality classification systems, attainment dates, and the integration of the implementation of the standards. The third category addresses potential violations of the standard and helping areas take proactive measures to avoid the designation process. Technical issues were also discussed including the need to increase air quality monitoring, emission inventory and air quality modeling issues, and the technical nature and relationship of ozone, fine particulate matter and regional haze. Finally, the Subcommittee discussed the development of control strategies. This discussion included the development of an alternative framework which would allow states increased flexibility in the design and implementation of control measures.

  5. 40 CFR Appendix P to Part 50 - Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... max 8-hour Conc. (ppm) 4th Highest daily max 8-hour Conc. (ppm) 5th Highest daily max 8-hour Conc.... (ppm) 3rd Highest daily max 8-hour Conc. (ppm) 4th Highest daily max 8-hour Conc. (ppm) 5th...

  6. Comparison of satellite measurements of ozone and ozone trends

    SciTech Connect

    Rusch, D.W.; Clancy, R.T.; Bhartia, P.K. |

    1994-10-01

    Measurements of ozone retrieved from satellite instruments over the 1979-1991 period are compared. The instruments used are the total ozone mapping spectrometer (TOMS), the solar backscattered ultraviolet experiment (SBUV), and stratospheric aerosol and gas experiments (SAGE) I and II. Although there is good agreement between the absolute densities of ozone as measured by the various instruments, the long-term changes (1979-1990) disagree sharply as a function of pressure and in the integrated ozone amount. In the upper stratosphere, SBUV trends are negative with maximum values of about -1.5%/year at high latitudes. Combined SAGE I and II trends are slightly positive in this region and peak near 0.5%/year at equatorial latitudes. In the lower stratosphere, SBUV trends reflect small decreases in ozone, generally less than -0.4%/year except at high southern latitudes where the trends rearch values of approximately -1.5%/year. SAGE ozone trends exhibit large decreases particularly in the equatorial regions where decreases of 3-6%/year are seen at pressures between 60 and 90 mbar. At higher latitudes, SAGE trends are more comparable to SBUV trends in the lower stratosphere. Total ozone trends from TOMS and SBUV agree within their uncertainties. Near-zero trends are indicated at low latitudes, and larger, negative trends (approximately -0.5%/year) are indicated near the poles. The SAGE column ozone trends depend upon the base level altitude of integration but do not exhibit a strong latitude dependence.

  7. Table Mountain ozone intercomparison: Brewer ozone spectrophotometer Umkehr observations

    SciTech Connect

    McElroy, C.T.; Kerr, J.B.

    1995-05-20

    The authors present the result of ozone column measurements, and vertical profiles, derived from Brewer ozone spectrophotometer measurements, in conjunction with the Umkehr technique. The Umkehr results agreed within 15% with the average measurments of this campaign between 20 and 40 km altitude. When restricted to the altitude range of 24 to 40 km the agreement was within about 5%.

  8. Historical trends and ozone forecasting for urban regions of South Texas using statistical and heuristic techniques

    NASA Astrophysics Data System (ADS)

    Brown, Ronald K.

    . Ideally, the models should be developed using an optimum quantity of data and input parameters. Findings from this study indicate that only two years of data would be sufficient to develop a model instead of using large quantities of data. The analyses of trends in observed data is important to understand the ozone formation and identify the periods of high ozone concentrations in a region. Statistical Regression Analysis and Artificial Neural Networks models were developed to forecast high ozone episodes of Corpus Christi, San Antonio and Victoria. The predictive capabilities of these models were compared to determine their accuracy in forecasting daily maximum eight-hour ozone and peak one-hour ozone concentration by different model evaluation statistics. Results of the study indicated that both models were able to capture trends in ozone time series, but they were unable to accurately forecast peak ozone values. Between the two models, the performance of the Statistical Analysis model LR - RMSE averages ranged from 13.55 to 15.96 and the Artificial Neural Networks model MLP - RMSE averages ranged from 12.56 to 14.96, there seems to be very little difference in the forecasting capabilities. Also, it should be noted that according to forecasting skill proficiency, the 8-hour ozone standard provided the highest probability of detection of a high ozone forecast than did the 1-hour standard. There is still a degree of uncertainty associated with the result of the findings concerning the models ability to make accurate forecast. Previous studies have also noted that the difference in the performance superiority of one modeling technique over the other is suspect. Where the skill proficiency of one model fails the other may succeed and vice versa.

  9. Ultraviolet Radiation and Stratospheric Ozone

    NASA Technical Reports Server (NTRS)

    Stolarski, R.

    2003-01-01

    Ultraviolet radiation from the sun produces ozone in the stratosphere and it participates in the destruction of ozone. Absorption of solar ultraviolet radiation by ozone is the primary heating mechanism leading to the maximum in temperature at the stratopause. Variations of solar ultraviolet radiation on both the 27-day solar rotation period and the 11-year solar cycle affect ozone by several mechanisms. The temperature and ozone in the upper stratosphere respond to solar uv variations as a coupled system. An increase in uv leads to an increase in the production of ozone through the photolysis of molecular oxygen. An increase in uv leads to an increase in temperature through the heating by ozone photolysis. The increase in temperature leads to a partially-offsetting decrease in ozone through temperature-dependent reaction rate coefficients. The ozone variation modulates the heating by ozone photolysis. The increase in ozone at solar maximum enhances the uv heating. The processes are understood and supported by long-term data sets. Variation in the upper stratospheric temperatures will lead to a change in the behavior of waves propagating upward from the troposphere. Changes in the pattern of wave dissipation will lead to acceleration or deceleration of the mean flow and changes in the residual or transport circulation. This mechanism could lead to the propagation of the solar cycle uv variation from the upper stratosphere downward to the lower stratosphere. This process is not well-understood and has been the subject of an increasing number of model studies. I will review the data analyses for solar cycle and their comparison to model results.

  10. Unequivocal detection of ozone recovery in the Antarctic Ozone Hole through significant increases in atmospheric layers with minimum ozone

    NASA Astrophysics Data System (ADS)

    de Laat, Jos; van Weele, Michiel; van der A, Ronald

    2015-04-01

    An important new landmark in present day ozone research is presented through MLS satellite observations of significant ozone increases during the ozone hole season that are attributed unequivocally to declining ozone depleting substances. For many decades the Antarctic ozone hole has been the prime example of both the detrimental effects of human activities on our environment as well as how to construct effective and successful environmental policies. Nowadays atmospheric concentrations of ozone depleting substances are on the decline and first signs of recovery of stratospheric ozone and ozone in the Antarctic ozone hole have been observed. The claimed detection of significant recovery, however, is still subject of debate. In this talk we will discuss first current uncertainties in the assessment of ozone recovery in the Antarctic ozone hole by using multi-variate regression methods, and, secondly present an alternative approach to identify ozone hole recovery unequivocally. Even though multi-variate regression methods help to reduce uncertainties in estimates of ozone recovery, great care has to be taken in their application due to the existence of uncertainties and degrees of freedom in the choice of independent variables. We show that taking all uncertainties into account in the regressions the formal recovery of ozone in the Antarctic ozone hole cannot be established yet, though is likely before the end of the decade (before 2020). Rather than focusing on time and area averages of total ozone columns or ozone profiles, we argue that the time evolution of the probability distribution of vertically resolved ozone in the Antarctic ozone hole contains a better fingerprint for the detection of ozone recovery in the Antarctic ozone hole. The advantages of this method over more tradition methods of trend analyses based on spatio-temporal average ozone are discussed. The 10-year record of MLS satellite measurements of ozone in the Antarctic ozone hole shows a

  11. IMPACT OF OZONE ON VEGETATION

    EPA Science Inventory

    Visible injury on vegetation is one of the earliest and most obvious manifestations of ozone injury. However, ozone effects are not limited to visible injury; impacts range from reduced plant growth, decreased yield, changes in crop quality and alterations in susceptibility to ab...

  12. Rocket ozone sounding network data

    NASA Technical Reports Server (NTRS)

    Wright, D. U.; Krueger, A. J.; Foster, G. M.

    1978-01-01

    During the period December 1976 through February 1977, three regular monthly ozone profiles were measured at Wallops Flight Center, two special soundings were taken at Antigua, West Indies, and at the Churchill Research Range, monthly activities were initiated to establish stratospheric ozone climatology. This report presents the data results and flight profiles for the period covered.

  13. IMPROVED TECHNIQUES FOR RESIDUAL OZONE

    EPA Science Inventory

    Eight analytical methods for the determination of residual ozone in water are evaluated. Four are iodometric methods based on the reduction of ozone by iodide ion: the iodometric method, the amperometric method, the arsenic (III) back titration method, and the N, N-diethyl-p-phen...

  14. Simplified ozone detection by chemiluminescence

    NASA Technical Reports Server (NTRS)

    Conway, E. J.; Rogowski, R. S.; Richards, R. R.

    1977-01-01

    Ozone is detected by film coated with solid, such as rubrene, that reacts with ozone to degree proportional to concentration in sample gas. Gas flow is stopped, and film is heated to produce light (chemiluminescence) in proportion to amount of reacted material on sensor.

  15. Plant responses to tropospheric ozone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropospheric ozone is the second most abundant air pollutant and an important component of the global climate change. Over five decades of research on the phytotoxicity of ozone in model plants systems, crop plants and forest trees have provided some insight into the physiological, biochemical and m...

  16. OZONE MULTI-YEAR PLAN

    EPA Science Inventory

    The tropospheric ozone research program addresses not only ozone, but other criteria pollutants such as SO2, nitrogen dioxide, carbon monoxide, and lead. It focuses on developing tools to help with implementation of National Ambient Air Quality Standards (NAAQS), such as improvin...

  17. Ozone Modeling Using Neural Networks.

    NASA Astrophysics Data System (ADS)

    Narasimhan, Ramesh; Keller, Joleen; Subramaniam, Ganesh; Raasch, Eric; Croley, Brandon; Duncan, Kathleen; Potter, William T.

    2000-03-01

    Ozone models for the city of Tulsa were developed using neural network modeling techniques. The neural models were developed using meteorological data from the Oklahoma Mesonet and ozone, nitric oxide, and nitrogen dioxide (NO2) data from Environmental Protection Agency monitoring sites in the Tulsa area. An initial model trained with only eight surface meteorological input variables and NO2 was able to simulate ozone concentrations with a correlation coefficient of 0.77. The trained model was then used to evaluate the sensitivity to the primary variables that affect ozone concentrations. The most important variables (NO2, temperature, solar radiation, and relative humidity) showed response curves with strong nonlinear codependencies. Incorporation of ozone concentrations from the previous 3 days into the model increased the correlation coefficient to 0.82. As expected, the ozone concentrations correlated best with the most recent (1-day previous) values. The model's correlation coefficient was increased to 0.88 by the incorporation of upper-air data from the National Weather Service's Nested Grid Model. Sensitivity analysis for the upper-air variables indicated unusual positive correlations between ozone and the relative humidity from 500 hPa to the tropopause in addition to the other expected correlations with upper-air temperatures, vertical wind velocity, and 1000-500-hPa layer thickness. The neural model results are encouraging for the further use of these systems to evaluate complex parameter cosensitivities, and for the use of these systems in automated ozone forecast systems.

  18. Rocket ozone sounding network data

    NASA Technical Reports Server (NTRS)

    Wright, D. U.; Krueger, A. J.; Foster, G. M.

    1979-01-01

    During the period March 1977 through May 1977, three regular monthly ozone profiles were measured at Wallops Flight Center and three regular monthly ozone profiles were measured at the Churchill Research Range. One additional flight was conducted at Wallops Flight Center in support of Nimbus 4 SBUV. Data results and flight profiles for the period covered are presented.

  19. Nonaqueous ozonation of vulcanized rubber

    DOEpatents

    Serkiz, Steven M.

    1999-01-01

    A process and resulting product is provided in which a solid particulate, such as vulcanized crumb rubber, has the surface functional groups oxidized by ozonation using a nonpolar solvent. The ozonation process renders the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger loading levels of the treated crumb rubber can be used in new rubber mixtures.

  20. Nonaqueous ozonation of vulcanized rubber

    SciTech Connect

    Serkiz, S.M.

    1999-12-07

    A process and resulting product are provided in which a solid particulate, such as vulcanized crumb rubber, has the surface functional groups oxidized by ozonation using a nonpolar solvent. The ozonation process renders the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger loading levels of the treated crumb rubber can be used in new rubber mixtures.

  1. Coupled Hydrological-Meteorological Modeling to Support Simulation of an Ozone Exceedance Episode over Texas

    NASA Astrophysics Data System (ADS)

    Barton, S.; Linder, K.; Stewart, A.; Peters-Lidard, C.; McHenry, J.; Coats, C.; Trayanov, A.

    2001-05-01

    Current meteorological modeling systems used to drive air quality models in support of State Implementation Planning are deficient. They often fail to adequately represent the three-dimensional evolution of the planetary boundary layer, the development and maintenance of low-level jets, and the formation, timing, location and extent of convective clouds. All of these factors contribute to failures in the modeling systems' simulations of critical air pollution episodes relied upon for policy-making purposes. Based on recent research, it is now understood that deficiencies in the underlying representation of the temporal and spatial variations in soil moisture lead to critical deficiencies in the ability of the current generation of meteorological models to reproduce complex flows and atmospheric states which modulate air quality, particularly in the weakly-forced environments typical of ozone exceedance events. We are improving upon these identified deficiencies by configuring an advanced, data-assimilating, high-resolution land-surface hydrology model (TOPLATS) to drive the overlying meteorological model (MM5) within the eight-county Houston Non-Attainment Area for the purpose of improving air quality predictions. Although our hypothesis is that appropriate modeling of soil moisture is critical for proper coupled modeling, we must rely on readily available streamflow data to validate the hydrologic predictions. Results for several validation watersheds-chosen by location, size, diversity of parameters, and available streamflow data-will be presented.

  2. Source attribution of tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Butler, T. M.

    2015-12-01

    Tropospheric ozone is a harmful pollutant with adverse effects on human health and ecosystems. As well as these effects, tropospheric ozone is also a powerful greenhouse gas, with an anthropogenic radiative forcing one quarter of that of CO2. Along with methane and atmospheric aerosol, tropospheric ozone belongs to the so-called Short Lived Climate forcing Pollutants, or SLCP. Recent work has shown that efforts to reduce concentrations of SLCP in the atmosphere have the potential to slow the rate of near-term climate change, while simultaneously improving public health and reducing crop losses. Unlike many other SLCP, tropospehric ozone is not directly emitted, but is instead influenced by two distinct sources: transport of air from the ozone-rich stratosphere; and photochemical production in the troposphere from the emitted precursors NOx (oxides of nitrogen), CO (Carbon Monoxide), and VOC (volatile organic compounds, including methane). Better understanding of the relationship between ozone production and the emissions of its precursors is essential for the development of targeted emission reduction strategies. Several modeling methods have been employed to relate the production of tropospheric ozone to emissions of its precursors; emissions perturbation, tagging, and adjoint sensitivity methods all deliver complementary information about modelled ozone production. Most studies using tagging methods have focused on attribution of tropospheric ozone production to emissions of NOx, even though perturbation methods have suggested that tropospheric ozone is also sensitive to VOC, particularly methane. In this study we describe the implementation into a global chemistry-climate model of a scheme for tagging emissions of NOx and VOC with an arbitrary number of labels, which are followed through the chemical reactions of tropospheric ozone production in order to perform attribution of tropospehric ozone to its emitted precursors. Attribution is performed to both

  3. Clathrate hydrates for ozone preservation.

    PubMed

    Muromachi, Sanehiro; Ohmura, Ryo; Takeya, Satoshi; Mori, Yasuhiko H

    2010-09-01

    We report the experimental evidence for the preservation of ozone (O(3)) encaged in a clathrate hydrate. Although ozone is an unstable substance and is apt to decay to oxygen (O(2)), it may be preserved for a prolonged time if it is encaged in hydrate cavities in the form of isolated molecules. This possibility was assessed using a hydrate formed from an ozone + oxygen gas mixture coexisting with carbon tetrachloride or xenon. Each hydrate sample was stored in an air-filled container at atmospheric pressure and a constant temperature in the range between -20 and 2 degrees C and was continually subjected to iodometric measurements of its fractional ozone content. Such chronological measurements and structure analysis using powder X-ray diffraction have revealed that ozone can be preserved in a hydrate-lattice structure for more than 20 days at a concentration on the order of 0.1% (hydrate-mass basis). PMID:20707330

  4. Ozone adsorption on carbon nanoparticles

    NASA Astrophysics Data System (ADS)

    Chassard, Guillaume; Gosselin, Sylvie; Visez, Nicolas; Petitprez, Denis

    2014-05-01

    Carbonaceous particles produced by incomplete combustion or thermal decomposition of hydrocarbons are ubiquitous in the atmosphere. On these particles are adsorbed hundreds of chemical species. Those of great concern to health are polycyclic aromatic hydrocarbons (PAHs). During atmospheric transport, particulate PAHs react with gaseous oxidants. The induced chemical transformations may change toxicity and hygroscopicity of these potentially inhalable particles. The interaction between ozone and carbon particles has been extensively investigated in literature. However ozone adsorption and surface reaction mechanisms are still ambiguous. Some studies described a fast catalytic decomposition of ozone initiated by an atomic oxygen chemisorption followed by a molecular oxygen release [1-3]. Others suggested a reversible ozone adsorption according to Langmuir-type behaviour [4,5]. The aim of this present study is a better understanding of ozone interaction with carbon surfaces. An aerosol of carbon nanoparticles was generated by flowing synthetic air in a glass tube containing pure carbon (primary particles < 50 nm), under magnetic stirring. The aerosol was then mixed with ozone in an aerosol flow tube. Ozone uptake experiments were performed with different particles concentrations with a fixed ozone concentration. The influence of several factors on kinetics was examined: initial ozone concentration, particle size (50 nm ≤ Dp ≤ 200 nm) and competitive adsorption (with probe molecule and water). The effect of initial ozone concentration was first studied. Accordingly to literature, it has been observed that the number of gas-phase ozone molecules lost per unit particle surface area tends towards a plateau for high ozone concentration suggesting a reversible ozone adsorption according to a Langmuir mechanism. We calculated the initial reaction probability between O3 and carbon particles.An initial uptake coefficient of 1.10-4 was obtained. Similar experiments were

  5. Chronic bronchiolitis in nonhuman primates after prolonged ozone exposure

    SciTech Connect

    Eustis, S.L.; Schwartz, L.W.; Kosch, P.C.; Dungworth, D.L.

    1981-01-01

    Bonnet monkeys (Macaca radiata) were exposed to 0.0, 0.5, or 0.8 ppm ozone for 7, 28, or 90 consecutive days, 8 hours per day. The pulmonary response was evaluated by means of pulmonary function testing, light microscopy, scanning electron microscopy, transmission microscopy, autoradiography, and morphometry. Pulmonary function values obtained before exposure did not statistically differ from values obtained after exposure. A general trend of increased quasistatic compliance of the lung was observed in both groups of exposed monkeys. Morphologic changes were principally characterized as low-grade chronic respiratory bronchiolitis. Tritiated thymidine labeling and counts of respiratory bronchiolar epithelium demonstrated up to a 37-fold increase in labeling index at 7 days but only a sevenfold increase at 90 days. Differential cell counts demonstrated an increase in the proportion of cuboidal bronchiolar cells constituting the respiratory bronchiolar epithelium. In control monkeys, 60% of the epithelial cells were cuboidal bronchiolar cells. At 90 days of exposure, more than 90% of the respiratory bronchiolar cells were cuboidal in appearance. The cuboidal bronchiolar cell in control monkeys does not appear secretory, but membrane-bound electron-dense secretory granules are present in this cell type from exposed monkeys. Epithelial hyperplasia (increased number of cells per millimeter of airway length) persisted through 90 days of exposure at a level slightly above that present at 7 days.

  6. Interannual Variability in Baseline Ozone and Its Relationship to Surface Ozone in the Western U.S.

    PubMed

    Baylon, Pao M; Jaffe, Daniel A; Pierce, R Bradley; Gustin, Mae S

    2016-03-15

    Baseline ozone refers to observed concentrations of tropospheric ozone at sites that have a negligible influence from local emissions. The Mount Bachelor Observatory (MBO) was established in 2004 to examine baseline air masses as they arrive to North America from the west. In May 2012, we observed an O3 increase of 2.0-8.5 ppbv in monthly average maximum daily 8-hour average O3 mixing ratio (MDA8 O3) at MBO and numerous other sites in the western U.S. compared to previous years. This shift in the O3 distribution had an impact on the number of exceedance days. We also observed a good correlation between daily MDA8 variations at MBO and at downwind sites. This suggests that under specific meteorological conditions, synoptic variation in O3 at MBO can be observed at other surface sites in the western U.S. At MBO, the elevated O3 concentrations in May 2012 are associated with low CO values and low water vapor values, consistent with transport from the upper troposphere/lower stratosphere (UT/LS). Furthermore, the Real-time Air Quality Modeling System (RAQMS) analyses indicate that a large flux of O3 from the UT/LS in May 2012 contributed to the observed enhanced O3 across the western U.S. Our results suggest that a network of mountaintop observations, LiDAR and satellite observations of O3 could provide key data on daily and interannual variations in baseline O3. PMID:26882468

  7. 35 state ozone transport region (OTAG) & ozone & PM NAAQS & regional HAZE FACA

    SciTech Connect

    Mathur, B.

    1996-11-01

    The activities of the 35 state ozone transport regions (OTAG) are summarized. Topics discussed include: the Chicago 15 percent plan; federal measures; VOC reduction goals; daily maximum ozone concentrations; ozone attainment demonstration policy; OTAG`s progress to date; significant upcoming activities; ozone transport assessment; model sensitivity analysis; FACA processes; and ozone, particulate matter, and regional haze implementation programs.

  8. Options to accelerate ozone recovery: ozone and climate benefits

    NASA Astrophysics Data System (ADS)

    Daniel, J. S.; Fleming, E. L.; Portmann, R. W.; Velders, G. J. M.; Jackman, C. H.; Ravishankara, A. R.

    2010-08-01

    Hypothetical reductions in future emissions of ozone-depleting substances (ODSs) and N2O are evaluated in terms of effects on equivalent effective stratospheric chlorine (EESC), globally-averaged total column ozone, and radiative forcing through 2100. Due to the established success of the Montreal Protocol, these actions can have only a fraction of the impact on ozone depletion that regulations already in force have had. If all anthropogenic ODS and N2O emissions were halted beginning in 2011, ozone is calculated to be higher by about 1-2% during the period 2030-2100 compared to a case of no additional restrictions. Direct radiative forcing by 2100 would be about 0.23 W/m2 lower from the elimination of anthropogenic N2O emissions and about 0.005 W/m2 lower from the destruction of the chlorofluorocarbon (CFC) bank. Due to the potential impact of N2O on future ozone levels, we provide an approach to incorporate it into the EESC formulation, which is used extensively in ozone depletion analyses. The ability of EESC to describe total ozone changes arising from additional ODS and N2O controls is also quantified.

  9. Nitroaromatic hydrocarbon ozonation in water. 1: Single ozonation

    SciTech Connect

    Beltran, F.J.; Encinar, J.M.; Alonso, M.A.

    1998-01-01

    Single ozonation of two nitroaromatic hydrocarbons (nitrobenzene and 2,6-dinitrotoluene) under different experimental conditions (ozone feed rate, pH, temperature, hydroxyl radical scavengers) has been studied. The absence of hydroxyl radical scavengers, pHs 7--9, and temperatures below 30 C are optimum conditions for nitroaromatic removal. Due to the importance of hydroxyl radical reactions, removal rates in natural water are much lower than those observed in laboratory ultrapure water. Rate constants of the direct reaction between ozone and nitroaromatic hydrocarbons at 20 C have been found to be lower than 6 M{sup {minus}1} s{sup {minus}1}. More than 99% of nitroaromatic removal is due to hydroxyl radical oxidation. Single ozonation of nitroaromatics can then be classified as a real advanced oxidation technology. Nitrophenols, compounds very reactive toward ozone and hydroxyl radicals, and 2,6-dinitrobenzaldehyde, identified in the single ozonation of nitrobenzene and 2,6-dinitrotoluene, respectively, are some of the first intermediates of single ozonation.

  10. Total ozone changes in the 1987 Antarctic ozone hole

    NASA Technical Reports Server (NTRS)

    Krueger, Arlin J.; Schoeberl, Mark R.; Doiron, Scott D.; Sechrist, Frank; Galimore, Reginald

    1988-01-01

    The development of the Antarctic ozone minimum was observed in 1987 with the Nimbus 7 Total Ozone Mapping Spectrometer (TOMS) instrument. In the first half of August the near-polar (60 and 70 deg S) ozone levels were similar to those of recent years. By September, however, the ozone at 70 and 80 deg S was clearly lower than any previous year including 1985, the prior record low year. The levels continued to decrease throughout September until October 5 when a new record low of 109 DU was established at a point near the South Pole. This value is 29 DU less than the lowest observed in 1985 and 48 DU less than the 1986 low. The zonal mean total ozone at 60 deg S remained constant throughout the time of ozone hole formation. The ozone decline was punctuated by local minima formed away from the polar night boundary at about 75 deg S. The first of these, on August 15 to 17, formed just east of the Palmer Peninsula and appears to be a mountain wave. The second major minimum formed on September 5 to 7 again downwind of the Palmer Peninsula. This event was larger in scale than the August minimum and initiated the decline of ozone across the polar region. The 1987 ozone hole was nearly circular and pole centered for its entire life. In previous years the hole was perturbed by intrusions of the circumpolar maximum into the polar regions, thus causing the hole to be elliptical. The 1987 hole also remained in place until the end of November, a few days longer than in 1985, and this persistence resulted in the latest time for recovery to normal values yet observed.

  11. Is the Ozone Hole over Your Classroom?

    ERIC Educational Resources Information Center

    Cordero, Eugene C.

    2002-01-01

    Reports on a survey of first year university science students regarding their understanding of the ozone layer, ozone depletion, and the effect of ozone depletion on Australia. Suggests that better teaching resources for environmental issues such as ozone depletion and global warming are needed before improvements in student understanding can be…

  12. Estimating the national public health burden associated with exposure to ambient PM2.5 and ozone.

    PubMed

    Fann, Neal; Lamson, Amy D; Anenberg, Susan C; Wesson, Karen; Risley, David; Hubbell, Bryan J

    2012-01-01

    Ground-level ozone (O(3)) and fine particulate matter (PM(2.5)) are associated with increased risk of mortality. We quantify the burden of modeled 2005 concentrations of O(3) and PM(2.5) on health in the United States. We use the photochemical Community Multiscale Air Quality (CMAQ) model in conjunction with ambient monitored data to create fused surfaces of summer season average 8-hour ozone and annual mean PM(2.5) levels at a 12 km grid resolution across the continental United States. Employing spatially resolved demographic and concentration data, we assess the spatial and age distribution of air-pollution-related mortality and morbidity. For both PM(2.5) and O(3) we also estimate: the percentage of total deaths due to each pollutant; the reduction in life years and life expectancy; and the deaths avoided according to hypothetical air quality improvements. Using PM(2.5) and O(3) mortality risk coefficients drawn from the long-term American Cancer Society (ACS) cohort study and National Mortality and Morbidity Air Pollution Study (NMMAPS), respectively, we estimate 130,000 PM(2.5) -related deaths and 4,700 ozone-related deaths to result from 2005 air quality levels. Among populations aged 65-99, we estimate nearly 1.1 million life years lost from PM(2.5) exposure and approximately 36,000 life years lost from ozone exposure. Among the 10 most populous counties, the percentage of deaths attributable to PM(2.5) and ozone ranges from 3.5% in San Jose to 10% in Los Angeles. These results show that despite significant improvements in air quality in recent decades, recent levels of PM(2.5) and ozone still pose a nontrivial risk to public health. PMID:21627672

  13. Corona discharge influences ozone concentrations near rats.

    PubMed

    Goheen, Steven C; Gaither, Kari; Anantatmula, Shantha M; Mong, Gary M; Sasser, Lyle B; Lessor, Delbert

    2004-02-01

    Ozone can be produced by corona discharge either in dry air or when one electrode is submerged in water. Since ozone is toxic, we examined whether ozone production by corona near laboratory animals could reach levels of concern. Male rats were exposed to a corona discharge and the concentration of ozone produced was measured. The resulting concentration of ozone ranged from ambient levels to 250 ppb when animals were located 1 cm from a 10 kV source. Similar ozone concentrations were observed when a grounded water source was present. Possible explanations for, as well as concerns regarding, ozone production under these conditions are discussed. PMID:14735560

  14. When will Antarctic ozone begin to recover?

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-01-01

    Emissions of ozone-depleting substances have declined over recent decades, but it takes time for the ozone layer to recover. Regular measurements of ozone levels above the South Pole now stretch back 25 years. Hassler et al. analyzed these recorded ozone data to assess changes in ozone loss rates. Consistent with previous studies, they found that ozone loss rates have been stable over the past 15 years, neither increasing nor decreasing. However, they predict that, assuming future atmospheric dynamics are similar to today's, ozone loss rates will begin to decline noticeably between 2017 and 2021. (Journal of Geophysical Research-Atmospheres, doi:10.1029/2011JD016353, 2011)

  15. Unprecedented Arctic ozone loss in 2011.

    PubMed

    Manney, Gloria L; Santee, Michelle L; Rex, Markus; Livesey, Nathaniel J; Pitts, Michael C; Veefkind, Pepijn; Nash, Eric R; Wohltmann, Ingo; Lehmann, Ralph; Froidevaux, Lucien; Poole, Lamont R; Schoeberl, Mark R; Haffner, David P; Davies, Jonathan; Dorokhov, Valery; Gernandt, Hartwig; Johnson, Bryan; Kivi, Rigel; Kyrö, Esko; Larsen, Niels; Levelt, Pieternel F; Makshtas, Alexander; McElroy, C Thomas; Nakajima, Hideaki; Parrondo, Maria Concepción; Tarasick, David W; von der Gathen, Peter; Walker, Kaley A; Zinoviev, Nikita S

    2011-10-27

    Chemical ozone destruction occurs over both polar regions in local winter-spring. In the Antarctic, essentially complete removal of lower-stratospheric ozone currently results in an ozone hole every year, whereas in the Arctic, ozone loss is highly variable and has until now been much more limited. Here we demonstrate that chemical ozone destruction over the Arctic in early 2011 was--for the first time in the observational record--comparable to that in the Antarctic ozone hole. Unusually long-lasting cold conditions in the Arctic lower stratosphere led to persistent enhancement in ozone-destroying forms of chlorine and to unprecedented ozone loss, which exceeded 80 per cent over 18-20 kilometres altitude. Our results show that Arctic ozone holes are possible even with temperatures much milder than those in the Antarctic. We cannot at present predict when such severe Arctic ozone depletion may be matched or exceeded. PMID:21964337

  16. The role of bay breezes and regional transport on a high surface ozone episode during the Houston, Texas DISCOVER-AQ field campaign

    NASA Astrophysics Data System (ADS)

    Loughner, C.; Follette-Cook, M. B.; Pickering, K. E.; Estes, M. J.

    2014-12-01

    The highest observed surface ozone concentrations in the Houston metropolitan area in 2013 occurred on September 25, which coincided with the Texas DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) field campaign. Surface ozone was elevated throughout the Houston metropolitan area. Maximum 8-hour average ozone peaked along the western shore of Galveston Bay, reaching 124 ppbv, almost 50 ppbv above the current EPA standard of 75 ppbv, at La Porte Sylvan Beach. Continental air pollution from the north and northeast was transported into the Houston metropolitan area where it mixed with locally generated emissions. A bay breeze circulation formed causing pollutants that were transported out over the water in the morning to recirculate back inland where they mixed with freshly emitted pollution near the bay breeze convergence zone. The highest surface ozone concentrations were reported near the bay breeze front at La Porte Sylvan Beach. This ozone episode will be presented using measurements made during the DISCOVER-AQ field campaign and WRF and CMAQ model simulations.

  17. Brewer Umkehr ozone profile retrievals

    NASA Astrophysics Data System (ADS)

    Petropavlovskikh, I. V.; Disterhoft, P.; Lantz, K. O.; Bhartia, P. K.; McPeters, R. D.; Flynn, L. E.; Oltmans, S. J.; Johnson, B. J.; Stanek, M.

    2011-12-01

    The Dobson Umkehr network has been a key data set for stratospheric ozone trend calculations (WMO Ozone assessments) and has earned its place as a benchmark network for stratospheric ozone profile observations. The Umkehr data has also been used to provide a long-term reference to the merging of the satellite ozone records (MOD), estimate the seasonal influence of an 11-year solar signal in the vertical distribution of stratospheric ozone, and to assess the ability of several remote and in-situ sensing systems in capturing ozone variability. It was found that Dobson Umkehr measurement errors were often comparable to errors derived for satellite and ozone-sounding methods. The Umkehr measurements are also available from the Brewer spectrophotometers [McElroy et al., 1995]. In 2005, the Dobson Umkehr algorithm (UMK04) was modified to retrieve ozone profile data from Brewer Umkehr measurements taken at two spectral channels [Petropavlovskikh et al, 2011]. The PC version of the Brewer algorithm was developed by M. Stanek (IOC, Canada and Czech Republic Meteorological Institute) in close collaboration with I. Petropavlovskikh. It was implemented at the NEUBrew network for operational processing of Umkehr data retrieved daily for all operational sites. The most recently developed Brewer ozone retrieval algorithm (MSBU) utilizes measurements that are currently available from the operational Brewer instruments. Umkehr measurements at multiple wavelength channels (similar to the satellite BUV method) and significantly reduced range of solar zenith angle are used for the twice a day operational ozone profile retrievals. Intercomparisons against ozone climatology, sounding, satellite overpasses and Dobson ozone datasets for NOASA/Goddard, Boulder, CO and MLO, HI sites are presented in this paper. The MSBU algorithm reduces noise in the intra-annual variability of the Brewer retrieved ozone as compared to the single pair ozone retrieval. Tropospheric ozone retrievals also

  18. Ozone is mutagenic in Salmonella

    SciTech Connect

    Dillon, D.; Combes, R.; McConville, M.; Zeiger, E. )

    1992-01-01

    Ozone is a highly reactive gas that has been tested for genotoxicity in a number of systems. Induced genetic damage resulting from ozone treatment may not be readily observed because of the high toxicity of the chemical and difficulties in generating and administering controlled concentrations. The mutagenicity of ozone was investigated in Salmonella typhimurium using a plate test protocol designed for reactive vapours and gases. Ozone, at two to three consecutive doses, induced weak, albeit statistically significant, mutagenic responses in tester strain TA102 with and without Aroclor-induced rat liver S9 (lowest effective mean concentration of 0.019 ppm; 35 min total exposure). However, dose-related responses were not always obtained. No mutagenicity was detected in strains TA98, TA100, or TA1535, with or without S9. In strain TA104, ozone induced a weak response only at a single dose with S9; this response was not reproducible. Mutagenicity was dependent on the ozone flow rate and total exposure time, with variations in the optimum dose-time regimen leading to toxicity or complete inactivity. The data show that ozone is a very weak bacterial mutagen and only when tested under narrowly prescribed, subtoxic dosing conditions.

  19. Total ozone trend over Cairo

    NASA Technical Reports Server (NTRS)

    Hassan, G. K. Y.

    1994-01-01

    A world wide interest in protecting ozone layer against manmade effects is now increasing. Assessment of the ozone depletion due to these activities depends on how successfully we can separate the natural variabilities from the data. The monthly mean values of total ozone over Cairo (30 05N) for the period 1968-1988, have been analyzed using the power spectral analysis technique. The technique used in this analysis does not depend on a pre-understanding of the natural fluctuations in the ozone data. The method depends on increasing the resolution of the spectral peaks in order to obtain the more accurate sinusoidal fluctuations with wavelength equal to or less than record length. Also it handles the possible sinusoidal fluctuations with wavelength equal to or less than record length. The results show that it is possible to detect some of the well known national fluctuations in the ozone record such as annual, semiannual, quasi-biennial and quasi-quadrennial oscillations. After separating the natural fluctuations from the ozone record, the trend analysis of total ozone over Cairo showed that a decrease of about -1.2% per decade has occurred since 1979.

  20. Trends in ozone profile measurements

    NASA Technical Reports Server (NTRS)

    Johnston, H.; Aikin, A.; Barnes, R.; Chandra, S.; Cunnold, D.; Deluisi, J.; Gille, J. C.; Hudson, R.; Mccormick, M. P.; Mcmaster, L.

    1989-01-01

    From an examination of the agreements and differences between different satellite instruments, it is difficult to believe that existing satellite instruments determine upper stratospheric ozone much better than 4 pct.; by extension, it probably would require at least a 4 pct. change to be reliably detected as a change. The best estimates of the vertical profiles of ozone change in the upper stratosphere between 1979 and 1986 are judged to be those given by the two SAGE satellite instruments. SAGE-2 minus SAGE-1 gives a much lower ozone reduction than that given by the archived Solar Backscatter UV data. The average SAGE profiles of ozone changes between 20 and 50 degs north and between 20 and 50 degs south are given. The SAGE-1 and SAGE-2 comparison gives an ozone reduction of about 4 pct. at 25 km over temperate latitudes. Five ground based Umkehr stations between 36 and 52 degs north, corrected for the effects of volcanic aerosols, report an ozone reduction between 1979 and 1987 at Umkehr layer 8 of 9 + or - 5 pct. The central estimate of upper stratospheric ozone reduction given by SAGE at 40 km is less than the central value estimated by the Umkehr method at layer 8.

  1. Effects of stratospheric ozone recovery on photochemistry and ozone air quality in the troposphere

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Wu, S.; Huang, Y.; Wang, Y.

    2014-04-01

    There has been significant stratospheric ozone depletion since the late 1970s due to ozone-depleting substances (ODSs). With the implementation of the Montreal Protocol and its amendments and adjustments, stratospheric ozone is expected to recover towards its pre-1980 level in the coming decades. In this study, we examine the implications of stratospheric ozone recovery for the tropospheric chemistry and ozone air quality with a global chemical transport model (GEOS-Chem). With a full recovery of the stratospheric ozone, the projected increases in ozone column range from 1% over the low latitudes to more than 10% over the polar regions. The sensitivity factor of troposphere ozone photolysis rate, defined as the percentage changes in surface ozone photolysis rate for 1% increase in stratospheric ozone column, shows significant seasonal variation but is always negative with absolute value larger than one. The expected stratospheric ozone recovery is found to affect the tropospheric ozone destruction rates much more than the ozone production rates. Significant decreases in surface ozone photolysis rates due to stratospheric ozone recovery are simulated. The global average tropospheric OH decreases by 1.7%, and the global average lifetime of tropospheric ozone increases by 1.5%. The perturbations to tropospheric ozone and surface ozone show large seasonal and spatial variations. General increases in surface ozone are calculated for each season, with increases by up to 0.8 ppbv in the remote areas. Increases in ozone lifetime by up to 13% are found in the troposphere. The increased lifetimes of tropospheric ozone in response to stratospheric ozone recovery enhance the intercontinental transport of ozone and global pollution, in particular for the summertime. The global background ozone attributable to Asian emissions is calculated to increase by up to 15% or 0.3 ppbv in the Northern Hemisphere in response to the projected stratospheric ozone recovery.

  2. ADVANCED OXIDATION: OXALATE DECOMPOSITION TESTING WITH OZONE

    SciTech Connect

    Ketusky, E.; Subramanian, K.

    2012-02-29

    dissolution equilibrium, and then decomposed to {le} 100 Parts per Million (ppm) oxalate. Since AOP technology largely originated on using ultraviolet (UV) light as a primary catalyst, decomposition of the spent oxalic acid, well exposed to a medium pressure mercury vapor light was considered the benchmark. However, with multi-valent metals already contained in the feed, and maintenance of the UV light a concern; testing was conducted to evaluate the impact from removing the UV light. Using current AOP terminology, the test without the UV light would likely be considered an ozone based, dark, ferrioxalate type, decomposition process. Specifically, as part of the testing, the impacts from the following were investigated: (1) Importance of the UV light on the decomposition rates when decomposing 1 wt% spent oxalic acid; (2) Impact of increasing the oxalic acid strength from 1 to 2.5 wt% on the decomposition rates; and (3) For F-area testing, the advantage of increasing the spent oxalic acid flowrate from 40 L/min (liters/minute) to 50 L/min during decomposition of the 2.5 wt% spent oxalic acid. The results showed that removal of the UV light (from 1 wt% testing) slowed the decomposition rates in both the F & H testing. Specifically, for F-Area Strike 1, the time increased from about 6 hours to 8 hours. In H-Area, the impact was not as significant, with the time required for Strike 1 to be decomposed to less than 100 ppm increasing slightly, from 5.4 to 6.4 hours. For the spent 2.5 wt% oxalic acid decomposition tests (all) without the UV light, the F-area decompositions required approx. 10 to 13 hours, while the corresponding required H-Area decompositions times ranged from 10 to 21 hours. For the 2.5 wt% F-Area sludge, the increased availability of iron likely caused the increased decomposition rates compared to the 1 wt% oxalic acid based tests. In addition, for the F-testing, increasing the recirculation flow rates from 40 liter/minute to 50 liter/minute resulted in an

  3. The National Ozone Expedition, 1986

    SciTech Connect

    Solomon, S. )

    1987-01-01

    Eighteen scientists from four separate institutions came to McMurdo Station during the period from August to November, 1986, to carry out an intensive stratospheric measurement program aimed at obtaining further data on the antarctic ozone hole. The results from the composite of experiments strongly suggest that chemistry (specifically, the chemistry of anthropogenically produced halocarbon species) probably plays an important role in the development of the antarctic ozone hole. If the antarctic ozone hole is due to mankind's use of chlorofluorocarbons, then it represents the first time that the environment has been shown to be sensitive to man's activities on a global scale.

  4. Ozone and ozonated oils in skin diseases: a review.

    PubMed

    Travagli, V; Zanardi, I; Valacchi, G; Bocci, V

    2010-01-01

    Although orthodox medicine has provided a variety of topical anti-infective agents, some of them have become scarcely effective owing to antibiotic- and chemotherapeutic-resistant pathogens. For more than a century, ozone has been known to be an excellent disinfectant that nevertheless had to be used with caution for its oxidizing properties. Only during the last decade it has been learned how to tame its great reactivity by precisely dosing its concentration and permanently incorporating the gas into triglycerides where gaseous ozone chemically reacts with unsaturated substrates leading to therapeutically active ozonated derivatives. Today the stability and efficacy of the ozonated oils have been already demonstrated, but owing to a plethora of commercial products, the present paper aims to analyze these derivatives suggesting the strategy to obtain products with the best characteristics. PMID:20671923

  5. Ozone and Ozonated Oils in Skin Diseases: A Review

    PubMed Central

    Travagli, V.; Zanardi, I.; Valacchi, G.; Bocci, V.

    2010-01-01

    Although orthodox medicine has provided a variety of topical anti-infective agents, some of them have become scarcely effective owing to antibiotic- and chemotherapeutic-resistant pathogens. For more than a century, ozone has been known to be an excellent disinfectant that nevertheless had to be used with caution for its oxidizing properties. Only during the last decade it has been learned how to tame its great reactivity by precisely dosing its concentration and permanently incorporating the gas into triglycerides where gaseous ozone chemically reacts with unsaturated substrates leading to therapeutically active ozonated derivatives. Today the stability and efficacy of the ozonated oils have been already demonstrated, but owing to a plethora of commercial products, the present paper aims to analyze these derivatives suggesting the strategy to obtain products with the best characteristics. PMID:20671923

  6. Dobson spectrophotometer ozone measurements during international ozone rocketsonde intercomparison

    NASA Technical Reports Server (NTRS)

    Parsons, C. L.

    1980-01-01

    Measurements of the total ozone content of the atmosphere, made with seven ground based instruments at a site near Wallops Island, Virginia, are discussed in terms for serving as control values with which the rocketborne sensor data products can be compared. These products are profiles of O3 concentration with altitude. By integrating over the range of altitudes from the surface to the rocket apogee and by appropriately estimating the residual ozone amount from apogee to the top of the atmosphere, a total ozone amount can be computed from the profiles that can be directly compared with the ground based instrumentation results. Dobson spectrophotometers were used for two of the ground-based instruments. Preliminary data collected during the IORI from Dobson spectrophotometers 72 and 38 are presented. The agreement between the two and the variability of total ozone overburden through the experiment period are discussed.

  7. Sensitivity Studies for Assimilated Ozone Profiles

    NASA Technical Reports Server (NTRS)

    Stajner, Ivanka; Winslow, Nathan; Wargan, Krzysztof; Rood, Richard; Pawson, Steven

    2002-01-01

    An ozone data assimilation system at the NASA/Goddard Data Assimilation Office (DAO) produces three-dimensional global ozone fields. They are obtained by assimilating ozone retrieved from the Solar Backscatter UltraViolet/2 (SBUV/2) instrument and the Earth Probe Total Ozone Mapping Spectrometer (EP TOMS) measurements into an off-line parameterized chemistry and transport model. In this talk we focus on the quality of lower stratospheric assimilated ozone profiles. Ozone in the lower stratosphere plays a key role in the forcing of climate. A biased ozone field in this region will adversely impact calculations of the stratosphere-troposphere exchange and, when used as a first guess in retrievals, the values determined from satellite observations. The SBUV/2 ozone data have a coarse vertical resolution with increased uncertainty below the ozone maximum, and TOMS provides only total ozone columns. Thus, the assimilated ozone profiles in the lower stratosphere are only weakly constrained by the incoming SBUV and TOMS data. Consequently, the assimilated ozone distribution should be sensitive to changes in inputs to the statistical analysis scheme. We investigate the sensitivity of assimilated ozone profiles to changes in a variety of system inputs: TOMS and SBUV/2 data selection, forecast and observations error covariance models, inclusion or omission of a parameterized chemistry model, and different versions of DAO assimilated wind fields used to drive the transport model. Comparisons of assimilated ozone fields with independent observations, primarily ozone sondes, are used to determine the impact of each of these changes.

  8. Identifying and forecasting deep stratospheric ozone intrusions over the western United States from space

    NASA Astrophysics Data System (ADS)

    Lin, M.; Fiore, A. M.; Horowitz, L. W.; Cooper, O. R.; Langford, A. O.; Pan, L.; Liu, X.; Reddy, P. J.

    2012-12-01

    Recent studies have shown that deep stratospheric ozone intrusions can episodically enhance ground-level ozone above the health-based standard over the western U.S. in spring. Advanced warning of incoming intrusions could be used by state agencies to inform the public about poor air quality days. Here we explore the potential for using total ozone retrievals (version 5.2, level 3) at twice daily near global coverage from the AIRS instrument aboard the NASA Aqua satellite to identify stratospheric intrusions and forecast the eventual surface destination of transported stratospheric ozone. The method involves the correlation of AIRS daily total ozone columns at each 1ox1o grid box ~1-3 days prior to stratospheric enhancements to daily maximum 8-hour average ozone at a selected surface site using datasets from April to June in 2003-2011. The surface stratospheric enhancements are estimated by the GFDL AM3 chemistry-climate model which includes full stratospheric and tropospheric chemistry and is nudged to reanalysis winds. Our earlier work shows that the model presents deep stratospheric intrusions over the Western U.S. consistently with observations from AIRS, surface networks, daily ozone sondes, and aircraft lidar available in spring of 2010 during the NOAA CalNex field campaign. For the 15 surface sites in the U.S. Mountain West considered, a correlation coefficient of 0.4-0.7 emerges with AIRS ozone columns over 30o-50oN latitudes and 125o-105oW longitudes - variability in the AIRS column within this spatial domain indicates incoming intrusions. For each "surface receptor site", the spatial domain can narrow to an area ~5ox5o northwest of the individual site, with the strong correlation (0.5-0.7) occurring when the AIRS data is lagged by 1 day from the AM3 stratospheric enhancements in surface air. The spatial pattern of correlations is consistent with our process-oriented understanding developed from case studies of extreme intrusions. Surface observations

  9. Ozone Monitoring Instrument

    NASA Astrophysics Data System (ADS)

    de Vries, Johan

    The Ozone Monitoring Instrument is a trace gas monitoring instrument in the line of GOME (ERS-2) and Sciamachy (ENVISAT). Following these instruments, OMI provides UV-visible spectroscopy with a resolution sufficient to separate out the various absorbing trace gases (using DOAS or `Full' retrieval), but shaped as an imaging spectrometer. This means that a two dimensional detector is used where one dimension records the spectrum and the other images the swath. The scanning mechanism from the GOME and Sciamachy is not required anymore and there are considerable advantages with respect to simultaneous measurement of swath pixels, polarisation and obtainable swath width. The OMI consortium for a phase B is formed by Fokker Space & Systems and TPD in the Netherlands and VTT in Finland. In the presentation UV-visible atmospheric remote sensing will be placed in perspective and the OMI will be explaned.

  10. The photolysis of ozone

    NASA Technical Reports Server (NTRS)

    Lissi, E.; Heicklen, J.

    1972-01-01

    Ozone was photolyzed at 25 C with steady illumination at several wavelengths from 2288 to 2850 A, at O3 pressures from 0.1 to 2.7 torr, and at absorbed intensities from 0.15 to 65 microns/min. Experiments were done in pure dry O3, and in the presence of He, CO2, N2, H2O, H2, N2O, He-CO2, He-H2O, CO2-H2O, O2-N2O, CO2-O2, and N2O5-O2-CO2 mixtures. The results show that in the absence of added gases or in the presence of He, the quantum yield of O3 consumption is 5.5 independent of conditions, except at pressures below 0.4 torr. In the presence of CO2 or N2, ozone consumption falls toward 4.0. The primary photolytic act produces O(1 D) and siglet O2, presumably O2(1 delta), at all wavelengths below 3000 A. Relative quenching constants O(1 D) removal by various gases were measured at 2288, 2537, and 2800 A. For O3, CO2, and N2, the relative rates are 1.0/0.4 to 0.5/0.08 to 0.11 at all wavelengths. For H2O the constant at 2537 A is 1.5 relative to that for O3. With N2O, a noticeable wavelength effect is observed and the relative rate constants are 1.5, 2 to 3, 4.0 for O3 compared to N2O at 2800, 2537, and 2288 A, respectively.

  11. Ozonation of cooling tower waters

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; French, K. R.; Howe, R. D. (Inventor)

    1979-01-01

    Continuous ozone injection into water circulating between a cooling tower and heat exchanger with heavy scale deposits inhibits formation of further deposits, promotes flaking of existing deposits, inhibits chemical corrosion and controls algae and bacteria.

  12. Air Quality Guide for Ozone

    MedlinePlus

    ... is one of our nation’s most common air pollutants. Use the chart below to help reduce your ... human health. Ozone forms when two types of pollutants (VOCs and NOx) react in sunlight. These pollutants ...

  13. A search For Artic ozone

    NASA Astrophysics Data System (ADS)

    Maggs, William Ward

    Four atmospheric scientists took off with their instruments for Greenland last week, where they will try to see if depletion of stratospheric ozone in the Arctic can be detected as it has been in Antarctica since 1985.Members of the scientific team include Susan Solomon and George Mount of the Aeronomy Laboratory at the National Atmospheric and Oceanic Administration (NOAA) in Boulder, Colo., and Ryan Sanders and Roger Jakoubec of the Cooperative Institute for Research in Environmental Science in Norman, Okla. These four participated in previous National Ozone Expedition (NOZE) investigations at McMurdo Station in Antarctica that helped document the ozone “hole,” decreases of up to 50% in ozone during the early austral spring in September and October of the last 2 years (1986-1987).

  14. Ozone - Current Air Quality Index

    MedlinePlus

    ... reducing exposure to extremely high levels of particle pollution is available here . Fires: Current Conditions Click to ... Air Quality Basics Air Quality Index | Ozone | Particle Pollution | Smoke from fires | What You Can Do Health ...

  15. Monsoon circulation and atmospheric ozone

    NASA Astrophysics Data System (ADS)

    Khrgian, A. Kh.; Nguyen, Van Thang

    1991-01-01

    The effect of the Indonesian-Australian winter monsoon, proceeding from the Asian continent to the south, on the atmospheric ozone is examined. It is shown that large-scale atmospheric circulation phenomena caused by monsoons in the tropical regions of Australia and in south-eastern Asia can cause significant falls in atmospheric ozone concentrations. The common occurrence of such phenomena might explain the higher-than-average incidence of skin cancer in Australia.

  16. Method of sterilization using ozone

    NASA Technical Reports Server (NTRS)

    Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor)

    2002-01-01

    Methods of using ozone have been developed which sterilize instruments and medical wastes, oxidize, organics found in wastewater, clean laundry, break down contaminants in soil into a form more readily digested by microbes, kill microorganisms present in food products, and destroy toxins present in food products. The preferred methods for killing microorganism and destroying toxins use pressurized, humidified, and concentrated ozone produced by an electrochemical cell.

  17. Ozone Treatment For Cooling Towers

    NASA Technical Reports Server (NTRS)

    Blackwelder, Rick; Baldwin, Leroy V.; Feeney, Ellen S.

    1990-01-01

    Report presents results of study of cooling tower in which water treated with ozone instead of usual chemical agents. Bacteria and scale reduced without pollution and at low cost. Operating and maintenance costs with treatment about 30 percent of those of treatment by other chemicals. Corrosion rates no greater than with other chemicals. Advantage of ozone, even though poisonous, quickly detected by smell in very low concentrations.

  18. Using ozone to treat cooling tower water

    SciTech Connect

    Webster, L.

    1995-07-01

    Ozone is a controversial but promising alternative to chemicals for treating water in cooling towers. A powerful disinfectant, ozone can prevent biofouling of heat exchange surfaces, and may mitigate scale and corrosion. Ozone treatment of cooling towers can cut costs for energy, water, sewage, and regulatory compliance. Ozone treatment is an electrotechnology, but ozone equipment represents only a small electric load. Although ozone has provided excellent results in some cooling tower applications, its effectiveness has not been proven conclusively. Less than 1,000 cooling towers use ozone water treatment in the United States. Acceptance of this technology is increasing, however, as indicated by its use by such large firms as IBM, AT and T, DuPont, and Xerox, and by its adoption by some chemical water treatment suppliers. The energy efficiency implications of ozone treatment are being researched. Southern California Edison found that in some systems, ozone treatment improved chiller efficiency up to 20 percent due to cleaner heat exchange surfaces.

  19. Corona Discharge Influences Ozone Concentrations Near Rats

    SciTech Connect

    Goheen, Steven C.; Gaither, Kari A.; Anantatmula, Shantha M.; Mong, Gary M.; Sasser, Lyle B.; Lessor, Delbert L.

    2004-02-26

    Ozone is produced by corona discharge in air. Its production is enhanced near grounded water. Whether grounded animals behave like grounded water, producing more ozone was investigated. Rats were exposed to corona discharge in a plastic cage. The concentration of ozone in the gas phase was monitored. The ozone concentration exceeded ambient levels only in the presence of corona discharge and either rats or water. When water or rats were exposed to corona discharge, ozone levels were more than 10 times higher than controls. Ozone levels increased rapidly with applied voltage. There was also a correlation between the distance of the corona needle to the rats and the amount of ozone produced. As the distance increased, ozone production decreased. These results are discussed in relation to the potential exposure of mammals to ozone in the vicinity of corona discharge and electric fields.

  20. Ground-level ozone in Alberta

    SciTech Connect

    Sandhu, H.S.

    1999-11-01

    This literature review on ground-level ozone in Alberta begins with introductory sections on the precursors and products of ozone formation, the chemistry and meteorology of ozone, and atmospheric ozone models. The subsequent section reviews ozone data from ambient air quality monitoring stations in Alberta. The final section discusses trends in ozone concentrations in urban and rural areas of Alberta, human and environmental health effects of ozone, proposed national ambient objectives and Canada-wide standards for ground-level ozone, and options for an ozone concentration standard for Alberta. Appendices include an outline of air pollutant monitoring methods used in Alberta, lists of monitoring stations, and tables of monitoring results for nitrogen oxides, total hydrocarbons, and volatile organic compounds at Calgary and Edmonton sites.

  1. Ground-level ozone in Alberta

    SciTech Connect

    Sandhu, H.S.

    1999-01-01

    This literature review on ground-level ozone in Alberta begins with introductory sections on the precursors and products of ozone formation, the chemistry and meteorology of ozone, and atmospheric ozone models. The subsequent section reviews ozone data from ambient air quality monitoring stations in Alberta. The final section discusses trends in ozone concentrations in urban and rural areas of Alberta, human and environmental health effects of ozone, proposed national ambient objectives and Canada-wide standards for ground-level ozone, and options for an ozone concentration standard for Alberta. Appendices include an outline of air pollutant monitoring methods used in Alberta, lists of monitoring stations, and tables of monitoring results for nitrogen oxides, total hydrocarbons, and volatile organic compounds at Calgary and Edmonton sites.

  2. The 2002 Antarctic Ozone Hole

    NASA Technical Reports Server (NTRS)

    Newman, P. A.; Nash, E. R.; Douglass, A. R.; Kawa, S. R.

    2003-01-01

    Since 1979, the ozone hole has grown from near zero size to over 24 Million km2. This area is most strongly controlled by levels of inorganic chlorine and bromine oncentrations. In addition, dynamical variations modulate the size of the ozone hole by either cooling or warming the polar vortex collar region. We will review the size observations, the size trends, and the interannual variability of the size. Using a simple trajectory model, we will demonstrate the sensitivity of the ozone hole to dynamical forcing, and we will use these observations to discuss the size of the ozone hole during the 2002 Austral spring. We will further show how the Cly decreases in the stratosphere will cause the ozone hole to decrease by 1-1.5% per year. We will also show results from a 3-D chemical transport model (CTM) that has been continuously run since 1999. These CTM results directly show how strong dynamics acts to reduce the size of the ozone hole.

  3. Wave-Like Ozone Movements

    NASA Astrophysics Data System (ADS)

    Roldugin, V. C.; Nikulin, G. N.; Henriksen, K.

    The wave-like character of the total ozone variations is examined from the Aral Sea and Karaganda observatories in Middle Asia, and from Tromsø and Murmansk in the Arctic. The waves have a period of 10-20 days and an amplitude of about 20-50 DU. They are seen practically every year when the ozone data do not contain too many gaps. In Middle Asia waves with the same periods are found in geopotential height and tropopause pressure variations. The ozone waves are caused by dynamic meteorological disturbances near the tropopause. The passing of a wave crest in the pressure field causes the convergence of ozone poor air under the tropopause and the divergence of ozone rich air above the tropopause giving rise to a total ozone content decrease. The passing of a wave trough stimulates the opposite process. By crosscorrelation analysis the wave-like movement was determined as eastward for both pairs of stations with a velocity of 11-15 °/day.

  4. Ozone Conference II: Abstract Proceedings

    SciTech Connect

    1999-11-01

    Ozone Conference II: Pre- and Post-Harvest Applications Two Years After Gras, was held September 27-28, 1999 in Tulare, California. This conference, sponsored by EPRI's Agricultural Technology Alliance and Southern California Edison's AgTAC facility, was coordinated and organized by the on-site ATA-AgTAC Regional Center. Approximately 175 people attended the day-and-a-half conference at AgTAC. During the Conference twenty-two presentations were given on ozone food processing and agricultural applications. Included in the presentations were topics on: (1) Ozone fumigation; (2) Ozone generation techniques; (3) System and design applications; (4) Prewater treatment requirements; (5) Poultry water reuse; (6) Soil treatments with ozone gas; and (7) Post-harvest aqueous and gaseous ozone research results. A live videoconference between Tulare and Washington, D.C. was held to discuss the regulators' view from inside the beltway. Attendees participated in two Roundtable Question and Answer sessions and visited fifteen exhibits and demonstrations. The attendees included university and governmental researchers, regulators, consultants and industry experts, technology developers and providers, and corporate and individual end-users. This report is comprised of the Abstracts of each presentation, biographical sketches for each speaker and a registration/attendees list.

  5. New dynamic NNORSY ozone profile climatology

    NASA Astrophysics Data System (ADS)

    Kaifel, A. K.; Felder, M.; Declercq, C.; Lambert, J.-C.

    2012-01-01

    Climatological ozone profile data are widely used as a-priori information for total ozone using DOAS type retrievals as well as for ozone profile retrieval using optimal estimation, for data assimilation or evaluation of 3-D chemistry-transport models and a lot of other applications in atmospheric sciences and remote sensing. For most applications it is important that the climatology represents not only long term mean values but also the links between ozone and dynamic input parameters. These dynamic input parameters should be easily accessible from auxiliary datasets or easily measureable, and obviously should have a high correlation with ozone. For ozone profile these parameters are mainly total ozone column and temperature profile data. This was the outcome of a user consultation carried out in the framework of developing a new, dynamic ozone profile climatology. The new ozone profile climatology is based on the Neural Network Ozone Retrieval System (NNORSY) widely used for ozone profile retrieval from UV and IR satellite sounder data. NNORSY allows implicit modelling of any non-linear correspondence between input parameters (predictors) and ozone profile target vector. This paper presents the approach, setup and validation of a new family of ozone profile climatologies with static as well as dynamic input parameters (total ozone and temperature profile). The neural network training relies on ozone profile measurement data of well known quality provided by ground based (ozonesondes) and satellite based (SAGE II, HALOE, and POAM-III) measurements over the years 1995-2007. In total, four different combinations (modes) for input parameters (date, geolocation, total ozone column and temperature profile) are available. The geophysical validation spans from pole to pole using independent ozonesonde, lidar and satellite data (ACE-FTS, AURA-MLS) for individual and time series comparisons as well as for analysing the vertical and meridian structure of different modes of

  6. Influence of synoptic patterns on surface ozone variability over the eastern United States from 1980 to 2012

    NASA Astrophysics Data System (ADS)

    Shen, L.; Mickley, L. J.; Tai, A. P. K.

    2015-10-01

    We investigate the effect of synoptic-scale weather patterns on observed maximum daily 8-hour average (MDA8) surface ozone over the eastern United States during 1980-2012 in summer (June-August, JJA). Zonally averaged, the relative standard deviation (SD) of daily MDA8 JJA ozone shows a bimodal structure, with peaks at 28-32 and 40-45° N, and we show that those regions are most influenced by the variability in daily weather. We apply empirical orthogonal functions (EOFs) to understand the causes of this structure. The first three leading EOF patterns explain 53 % of the total variance in detrended surface ozone, displaying (1) a widespread response of ozone in the eastern United States associated with north-south movement of jet wind latitude, (2) a north-south pattern linked to the Bermuda High system when its west boundary is located along the east coast, and (3) an east-west pattern characteristic of a westward extension of the Bermuda High and an enhanced Great Plains low level jet (GPLLJ). The northern peak of ozone relative SD can be explained by polar jet activity, while the southern peak appears related to variability in the Bermuda High and GPLLJ. We define a new metric polar jet frequency as the total number of days the jet traverses the Midwest and northeast each summer. In the Midwest and northeast, we find that the correlation coefficient r between detrended mean JJA MDA8 ozone and the polar jet frequency ranges between -0.76 and -0.93 over 1980-2012 depending on the time period selected, suggesting that polar jet frequency could provide a simple metric to predict ozone variability in future climate regimes. In the southeast, the influence of the Bermuda High on mean JJA MDA8 ozone depends on the location of its west edge. For those summers when the average position of the west edge is located west of ~ 85.4° W, a westward shift in the Bermuda High west edge increases ozone in the southeast by ~ 1 ppbv deg-1 in longitude. For all summers, a northward

  7. Seasonal variability of surface ozone in Korea

    NASA Astrophysics Data System (ADS)

    Wie, J.; Moon, B. K.; Choi, H.

    2015-12-01

    Tropospheric ozone around East Asia include Korea impacts on air quality and climate, and has been increased with rapid economic growth. To better understanding, we analyzed seasonal variability of tropospheric ozone simulated by using GEOS-Chem. Surface ozone concentration in Korea has double peaks in April and September. Tropospheric ozone increases primarily associated with westerly wind anomaly in spring, with warming in summer and autumn, and with cloud depletion in winter. Surface ozone in spring elevated after mature-phase El Niño winters. Key words: surface ozone, seasonal variability, Korea, East Asia Acknowledgements This work was supported by Korea Ministry of Environment as "Climate Change Correspondence Program."

  8. Scientific assessment of ozone depletion: 1991

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Over the past few years, there have been highly significant advances in the understanding of the impact of human activities on the Earth's stratospheric ozone layer and the influence of changes in chemical composition of the radiative balance of the climate system. Specifically, since the last international scientific review (1989), there have been five major advances: (1) global ozone decreases; (2) polar ozone; (3) ozone and industrial halocarbons; (4) ozone and climate relations; and (5) ozone depletion potentials (ODP's) and global warming potentials (GWP's). These topics and others are discussed.

  9. The 1991 Antarctic ozone hole - TOMS observations

    NASA Technical Reports Server (NTRS)

    Krueger, Arlin; Schoeberl, Mark; Newman, Paul; Stolarski, Richard

    1992-01-01

    The 1991 Antarctic springtime ozone decline, as measured by the Total Ozone Mapping Spectrometer (TOMS), was similar to those of earlier deep ozone hole years, 1987, 1989, and 1990. The minimum total ozone value was recorded on October 5, 1991 at 108 Dobson units near the South Pole. This was 8 DU lower than in any of the earlier years. Four of the last five years have exhibited an extensive, deep ozone hole. The area of the hole was about the same as in 1987, 1989, and 1990. The recovery of the low total ozone values occurred in mid-November as the polar vortex broke up.

  10. Tropospheric Ozone Over North America

    NASA Astrophysics Data System (ADS)

    Oltmans, S. J.; Thompson, A. M.; Cooper, O. R.; Merrill, J. T.; Tarasick, D. W.; Newchurch, M. J.

    2007-05-01

    Ozone in the troposphere plays a significant role as an absorber of infrared radiation (greenhouse gas), in the cleansing capacity of the atmosphere as a precursor of hydroxol radical formation, and a regulated air pollutant capable of deleterious health and ecosystem effects. Knowledge of the ozone budget in the troposphere over North America (NA) is required to properly understand the various mechanisms that contribute to the measured distribution and to develop and test models capable of simulating and predicting this key player in atmospheric chemical and physical processes. Recent field campaigns including the 2004 and 2006 INTEX Ozone Network Studies (IONS) http:croc.gsfc.nasa.gov/intexb/ions06.html that have included intensive ozone profile measurements from ozonesondes provide a unique data set for describing tropospheric ozone over a significant portion of the North American continent. These campaigns have focused on the spring and summer seasons when tropospheric ozone over NA is particularly influenced by long-range transport processes, significant photochemical ozone production resulting from both anthropogenic and natural (lightning) precursor emissions, and exchange with the stratosphere. This study uses ozone profiles measured over NA in the latitude band from approximately 12-60N, extending from the tropics to the high mid latitudes, to describe the seasonal behavior of tropospheric ozone over NA with an emphasis on the spring and summer. This includes the variability within seasons at a particular site as well as the contrasts between the seasons. Emphasis is placed on the variations among the sites including latitudinal and longitudinal gradients and how these differ through the seasons and with altitude in the troposphere. Regional differences are most pronounced during the summer season likely reflecting the influence of a wider variation in processes influencing the tropospheric ozone distribution including lightning NOX production in the upper

  11. Global tropospheric ozone investigations

    NASA Technical Reports Server (NTRS)

    Browell, Edward V.

    1998-01-01

    Ozone (O3) is one of the most important trace gases in the troposphere, and it is responsible for influencing many critical chemical and radiative processes. Ozone contributes to the formation of the hydroxyl radical (OH), which is central to most chemical reactions in the lower atmosphere, and it absorbs UV, visible, and infrared radiation which affects the energy budget and atmospheric temperatures. In addition, O3 can be used as a tracer of atmospheric pollution and stratosphere troposphere exchange. At elevated concentrations, O3 can also produce detrimental biological and human health effects. The US National Research Council (NRC) Board on Sustainable Development reviewed the US Global Change Research Program (USGCRP) [NRC, 1995], and it identified tropospheric chemistry as one of the high priority areas for the USGCRP in the next decade. The NRC identified the following specific challenges in tropospheric chemistry. Although we understand the reason for the high levels of 03 over several regions of the world, we need to better establish the distribution of O3 in the troposphere in order to document and understand the changes in the abundance of global tropospheric O3. This information is needed to quantify the contribution of O3 to the Earth' s radiative balance and to understand potential impacts on the health of the biosphere. Having recognized the importance of particles in the chemistry of the stratosphere, we must determine how aerosols and clouds affect the chemical processes in the troposphere. This understanding is essential to predict the chemical composition of the atmosphere and to assess the resulting forcing effects in the climate system. We must determine if the self-cleansing chemistry of the atmosphere is changing as a result of human activities. This information is required to predict the rate at which pollutants are removed from the atmosphere. Over nearly two decades, airborne Differential Absorption Lidar (DIAL) systems have been used in

  12. Issues in Stratospheric Ozone Depletion.

    NASA Astrophysics Data System (ADS)

    Lloyd, Steven Andrew

    Following the announcement of the discovery of the Antarctic ozone hole in 1985 there have arisen a multitude of questions pertaining to the nature and consequences of polar ozone depletion. This thesis addresses several of these specific questions, using both computer models of chemical kinetics and the Earth's radiation field as well as laboratory kinetic experiments. A coupled chemical kinetic-radiative numerical model was developed to assist in the analysis of in situ field measurements of several radical and neutral species in the polar and mid-latitude lower stratosphere. Modeling was used in the analysis of enhanced polar ClO, mid-latitude diurnal variation of ClO, and simultaneous measurements of OH, HO_2, H_2 O and O_3. Most importantly, such modeling was instrumental in establishing the link between the observed ClO and BrO concentrations in the Antarctic polar vortex and the observed rate of ozone depletion. The principal medical concern of stratospheric ozone depletion is that ozone loss will lead to the enhancement of ground-level UV-B radiation. Global ozone climatology (40^circS to 50^ circN latitude) was incorporated into a radiation field model to calculate the biologically accumulated dosage (BAD) of UV-B radiation, integrated over days, months, and years. The slope of the annual BAD as a function of latitude was found to correspond to epidemiological data for non-melanoma skin cancers for 30^circ -50^circN. Various ozone loss scenarios were investigated. It was found that a small ozone loss in the tropics can provide as much additional biologically effective UV-B as a much larger ozone loss at higher latitudes. Also, for ozone depletions of > 5%, the BAD of UV-B increases exponentially with decreasing ozone levels. An important key player in determining whether polar ozone depletion can propagate into the populated mid-latitudes is chlorine nitrate, ClONO_2 . As yet this molecule is only indirectly accounted for in computer models and field

  13. Distribution of total ozone and stratospheric ozone in the tropics - Implications for the distribution of tropospheric ozone

    NASA Technical Reports Server (NTRS)

    Fishman, Jack; Larsen, Jack C.

    1987-01-01

    Climatologies of total columnar ozone and integrated stratospheric ozone amounts at low latitudes (15 deg N to 15 deg S), derived from satellite observations, are presented. A significant longitudinal variability in total ozone is present, with highest values generally located between 60 deg W and 60 deg E. The integrated stratospheric component of total ozone, on the other hand, does not exhibit a longitudinal preference for high values. Therefore it is hypothesized that the climatological longitudinal distribution of total ozone reflects the variability of the abundance of tropospheric ozone at low latitudes. Furthermore, it is speculated that in situ photochemical production of ozone resulting from biomass burning may be responsible for the observed enhancement of total ozone at these longitudes.

  14. Assimilation of MLS and OMI Ozone Data

    NASA Technical Reports Server (NTRS)

    Stajner, I.; Wargan, K.; Chang, L.-P.; Hayashi, H.; Pawson, S.; Froidevaux, L.; Livesey, N.

    2005-01-01

    Ozone data from Aura Microwave Limb Sounder (MLS) and Ozone Monitoring Instrument (OMI) were assimilated into the ozone model at NASA's Global Modeling and Assimilation Office (GMAO). This assimilation produces ozone fields that are superior to those from the operational GMAO assimilation of Solar Backscatter Ultraviolet (SBUV/2) instrument data. Assimilation of Aura data improves the representation of the "ozone hole" and the agreement with independent Stratospheric Aerosol and Gas Experiment (SAGE) III and ozone sonde data. Ozone in the lower stratosphere is captured better: mean state, vertical gradients, spatial and temporal variability are all improved. Inclusion of OMI and MLS data together, or separately, in the assimilation system provides a way of checking how consistent OMI and MLS data are with each other, and with the ozone model. We found that differences between OMI total ozone column data and model forecasts decrease after MLS data are assimilated. This indicates that MLS stratospheric ozone profiles are consistent with OMI total ozone columns. The evaluation of error characteristics of OMI and MLS ozone will continue as data from newer versions of retrievals becomes available. We report on the initial step in obtaining global assimilated ozone fields that combine measurements from different Aura instruments, the ozone model at the GMAO, and their respective error characteristics. We plan to use assimilated ozone fields in estimation of tropospheric ozone. We also plan to investigate impacts of assimilated ozone fields on numerical weather prediction through their use in radiative models and in the assimilation of infrared nadir radiance data from NASA's Advanced Infrared Sounder (AIRS).

  15. Lower tropospheric ozone and aerosol measurements at a coastal mountain site in Central California

    NASA Astrophysics Data System (ADS)

    Post, A.; Faloona, I. C.; Lighthall, D.; Wexler, A. S.; Cliff, S. S.; Conley, S. A.; Zhao, Y.

    2013-12-01

    Increasing concern over the impacts of exogenous air pollution in California's Central Valley has prompted the establishment of a coastal, high altitude monitoring site at the Chews Ridge Observatory (1550 m) approximately 30 km east of Point Sur in Monterey County, operated by the Monterey Institute for Research in Astronomy. Eighteen months of ozone and aerosol measurements are presented in the context of long-range transport and its potential impact on surface air quality in the southern San Joaquin Valley. Moreover, several ozone surveys have been conducted by aircraft upwind, over the Pacific Ocean, and downwind, over the Central Valley, to characterize horizontal and vertical transport across the coastal mountains. Diurnal variations present at Chews Ridge indicate the formation of a convective boundary layer on the ridge during the daytime leading to a 6-8 ppb decrease in ozone accompanied by a rise in specific humidity of 2-3 g/kg due to coupling with the forest. During the nighttime, the sampled air masses are representative of free tropospheric conditions which have not been significantly influenced by either local emissions nor convective coupling to the surface. The maximum daily 8-hour average ozone concentration at Chews Ridge is used in lagged correlation analysis with two sites in the San Joaquin Valley, Fresno and Arvin, to de-emphasize the influence of locally produced, diurnally cycled ozone. The correlation coefficients (~0.60) peak between 9-21 hour lag and tend to decorrelate completely within 4-5 days. These and other analyses along with data provided by the aircraft sampling are used to provide a deeper understanding of ozone transport into the San Joaquin Valley. Aerosol size is measured with a scanning mobility particle sizer and composition is analyzed with an 8-stage rotating drum impactor whose substrates are characterized by X-ray fluorescence. Various elemental ratios and back trajectory calculations are used to infer the temporal

  16. A Study on Generation Ice Containing Ozone

    NASA Astrophysics Data System (ADS)

    Yoshimura, Kenji; Koyama, Shigeru; Yamamoto, Hiromi

    Ozone has the capability of sterilization and deodorization due to high oxidation power. It is also effective for the conservation of perishable foods and purification of water. However, ozone has a disadvantage, that is, conservation of ozone is difficult because it changes back into oxygen. Recently, ice containing ozone is taken attention for the purpose of its conservation. The use of ice containing ozone seems to keep food fresher when we conserve and transport perishable foods due to effects of cooling and sterilization of ice containing ozone. In the present study, we investigated the influence of temperatures of water dissolving ozone on the timewise attenuations of ozone concentration in water. We also investigated the influence of cooling temperature, ice diameter, initial temperatures of water dissolving ozone and container internal pressure of the water dissolving ozone on ozone concentration in the ice. In addition, we investigated the influence of the ice diameter on the timewise attenuations of ozone concentration in the ice. It was confirmed that the solidification experimental data can be adjusted by a correlation between ozone concentration in the ice and solidification time.

  17. Record Arctic ozone depletion could occur again

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-02-01

    In the winter of 2010-2011, ozone levels above the Arctic declined to record lows, creating the first Arctic ozone hole, similar to the well-known Antarctic ozone hole. Scientists believe the ozone depletion was due partly to unusually cold temperatures in the stratosphere above the Arctic, as colder stratospheric temperatures make ozone-destroying chemicals such as chlorine more active. As global climate change continues, the Arctic stratosphere is expected to get colder, but levels of ozone-destroying chemicals should decline, as emissions of these chemicals were banned by the Montreal Protocol. To try to learn more about Arctic ozone dynamics and determine whether the Arctic ozone hole is likely to recur, Sinnhuber et al. looked at satellite observations of temperature, ozone, water vapor, and chemicals that affect ozone in the Arctic atmosphere. They also used a model to determine how sensitive ozone levels are to stratospheric temperatures and chemistry. They found that their model accurately reproduced measured conditions. Their model suggests that stratospheric temperatures 1°C lower than in the 2010-2011 winter would result in locally nearly complete ozone depletion in the Arctic lower stratosphere with current levels of chemicals. A 10% reduction in ozone-depleting chemicals would be offset by a 1°C decrease in stratospheric temperatures.

  18. Spatial observation of the ozone layer

    NASA Astrophysics Data System (ADS)

    Godin-Beekmann, Sophie

    2010-04-01

    This article provides an overview of the various satellite instruments, which have been used to observe stratospheric ozone and other chemical compounds playing a key role in stratospheric chemistry. It describes the various instruments that have been launched since the late 1970s for the measurement of total ozone column and ozone vertical profile, as well as the major satellite missions designed for the study of stratospheric chemistry. Since the discovery of the ozone hole in the early 1980s, spatial ozone measurements have been widely used to evaluate and quantify the spatial extension of polar ozone depletion and global ozone decreasing trends as a function of latitude and height. Validation and evaluation of satellite ozone data have been the subject of intense scientific activity, which was reported in the various ozone assessments of the state of the ozone layer published after the signature of the Montreal protocol. Major results, based on satellite observations for the study of ozone depletion at the global scale and chemical polar ozone loss, are provided. The use of satellite observations for the validation of chemistry climate models that simulate the recovery of the ozone layer and in data assimilation is also described.

  19. Observing Tropospheric Ozone From Space

    NASA Technical Reports Server (NTRS)

    Fishman, Jack

    2000-01-01

    The importance of tropospheric ozone embraces a spectrum of relevant scientific issues ranging from local environmental concerns, such as damage to the biosphere and human health, to those that impact global change questions, Such is climate warming. From an observational perspective, the challenge is to determine the tropospheric ozone global distribution. Because its lifetime is short compared with other important greenhouse gases that have been monitored over the past several decades, the distribution of tropospheric ozone cannot be inferred from a relatively small set of monitoring stations. Therefore, the best way to obtain a true global picture is from the use of space-based instrumentation where important spatial gradients over vast ocean expanses and other uninhabited areas can be properly characterized. In this paper, the development of the capability to measure tropospheric ozone from space over the past 15 years is summarized. Research in the late 1980s successfully led to the determination of the climatology of tropospheric ozone as a function of season; more recently, the methodology has improved to the extent where regional air pollution episodes can be characterized. The most recent modifications now provide quasi-global (50 N) to 50 S) maps on a daily basis. Such a data set would allow for the study of long-range (intercontinental) transport of air pollution and the quantification of how regional emissions feed into the global tropospheric ozone budget. Future measurement capabilities within this decade promise to offer the ability to provide Concurrent maps of the precursors to the in situ formation of tropospheric ozone from which the scientific community will gain unprecedented insight into the processes that control global tropospheric chemistry

  20. Abiotic Buildup of Ozone

    NASA Astrophysics Data System (ADS)

    Domagal-Goldman, S. D.; Meadows, V. S.

    2010-10-01

    Two of the best biosignature gases for remote detection of life on extrasolar planets are oxygen (O2) and its photochemical byproduct, ozone (O3). The main reason for their prominence as biosignatures is that large abiotic fluxes of O2 and O3 are not considered sustainable on geological and astronomical timescales. We show here how buildup of O3 can occur on planets orbiting M stars, even in the absence of the large biological fluxes. This is possible because the destruction of O2 and O3 is driven by UV photochemistry. This chemistry is much slower on planets around these stars, due to the smaller incident UV flux. Because the destruction of these gases is slower, O3 can build up to detectable levels even if the O3 source is small. We will present atmospheric profiles of these gases for planets around AD Leo (an M dwarf) as well as spectra that show the implications for missions such as Darwin and the Terrestrial Planet Finder (TPF).