AREP GURME Section 11 Case Studies of Episodes

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AREP GURME Section 11 Case Studies of Episodes What is a Case Study? How

AREP GURME Section 11 Case Studies of Episodes What is a Case Study? How to Conduct Case Studies Examples

AREP GURME What is a Case Study? Analysis of the causes of an air

AREP GURME What is a Case Study? Analysis of the causes of an air quality episode Case studies provide insight into important processes Components of a case study • • • Air quality conditions Weather situation Summary of episode – Important air quality processes – Important meteorological processes Section 11 – Case Study of Episodes 2

AREP GURME How to Conduct Case Studies 1. Select a few air quality episodes

AREP GURME How to Conduct Case Studies 1. Select a few air quality episodes to study 1. Include ramp-up and cleanout days 2. 3. 4. 5. 6. 7. Review locations, magnitude, and duration of poor air quality Review surface and upper-air weather patterns Create backward trajectories to estimate transport Estimate upwind air quality to quantify local versus background contributions Review the temperature soundings to estimate vertical mixing Summarize the important processes that produced the episode Section 11 – Case Study of Episodes 3

AREP GURME Examples Each example includes • • Location and background Air quality conditions

AREP GURME Examples Each example includes • • Location and background Air quality conditions Weather situation (surface, upper-air, stability, winds, etc. ) Summary of episode (air quality and meteorology) Case study examples • • PM 10 episode Ozone episode PM 2. 5 episode CO episode Long-range transport episode Multi-pollutant episode Smoke episode Section 11 – Case Study of Episodes 4

AREP GURME Case Study of PM 10 Episode in Cairo, Egypt ● ● Location

AREP GURME Case Study of PM 10 Episode in Cairo, Egypt ● ● Location and background Air quality conditions Weather situation Summary of episode (air quality and meteorology) Section 11 – Case Study of Episodes 5

AREP GURME Location – Cairo, Egypt Cairo Section 11 – Case Study of Episodes

AREP GURME Location – Cairo, Egypt Cairo Section 11 – Case Study of Episodes 6

AREP GURME Air Quality Conditions Time series plot of PM 10 concentrations in Cairo

AREP GURME Air Quality Conditions Time series plot of PM 10 concentrations in Cairo in October 1999. The October 20 -25, 1999, episode is outlined (Dye et al. , 2000). Section 11 – Case Study of Episodes 7

AREP GURME Weather Situation (1 of 6) Surface and upper-air weather patterns H 500

AREP GURME Weather Situation (1 of 6) Surface and upper-air weather patterns H 500 -mb heights (dm) (solid) and 850 -mb temperatures (o. C) (dashed) (left), and sea level pressure (mb) and surface wind flags (right) on October 20, 1999, at 1400 LT Section 11 – Case Study of Episodes 8

AREP GURME Weather Situation (2 of 6) Surface and upper-air weather patterns L Light

AREP GURME Weather Situation (2 of 6) Surface and upper-air weather patterns L Light northerly winds Weak trough just passed 500 -mb heights (dm) (solid) and 850 -mb temperatures (o. C) (dashed) (left), and sea level pressure (mb) and surface wind flags (right) on October 23, 1999, (high PM day) at 1400 LT Section 11 – Case Study of Episodes 9

AREP GURME Weather Situation (3 of 6) Surface and upper-air weather patterns Moderate northerly

AREP GURME Weather Situation (3 of 6) Surface and upper-air weather patterns Moderate northerly winds Strong trough just passed 500 -mb heights (dm) (solid) and 850 -mb temperatures (o. C) (dashed) (left), and sea level pressure (mb) and surface wind flags (right) on October 25, 1999, (cleanout day) at 1400 LT Section 11 – Case Study of Episodes 10

AREP GURME Weather Situation (4 of 6) Backward trajectories to estimate transport 32 20

AREP GURME Weather Situation (4 of 6) Backward trajectories to estimate transport 32 20 -Oct 21 -Oct Latitude (degrees) 31. 5 22 -Oct 23 -Oct 24 -Oct 25 -Oct 21 25 22 31 20 24 23 30. 5 Short transport on high PM day 30 29. 5 30 30. 5 31 Longitude (degrees) 31. 5 32 32. 5 12 -hr backward trajectories ending in Cairo at 1400 LT each day October 20 to 25, 1999. Section 11 – Case Study of Episodes 11

AREP GURME Weather Situation (5 of 6) Upper-air nighttime soundings to estimate vertical mixing

AREP GURME Weather Situation (5 of 6) Upper-air nighttime soundings to estimate vertical mixing 0200 LT temperature soundings taken at Helwan from October 20 to 25, 1999. Section 11 – Case Study of Episodes 12

AREP GURME Weather Situation (6 of 6) Height (m) Upper-air daytime soundings to estimate

AREP GURME Weather Situation (6 of 6) Height (m) Upper-air daytime soundings to estimate vertical mixing Warming 24 21 22 20 25 23 Temperature (ºC) 1400 LT temperature soundings taken at Helwan from October 20 to 25, 1999. Section 11 – Case Study of Episodes 13

AREP GURME Summary of Episode characteristics • Weak upper-level troughs passed over and north

AREP GURME Summary of Episode characteristics • Weak upper-level troughs passed over and north of Egypt • The troughs lowered surface pressures to the north, thereby weakening the northerly winds, but winds still remained light-to-moderate from the north • Aloft temperatures warmed, the capping inversion lowered, and vertical mixing was reduced • Despite the moderately strong northerly winds, the reduced vertical mixing allowed for high PM 10 concentrations • The episode ended when a strong trough followed by a ridge passed over Egypt, increasing the northerly winds and weakening the inversion Section 11 – Case Study of Episodes 14

AREP GURME Examples 1. 2. GTT – Please provide examples of other case studies

AREP GURME Examples 1. 2. GTT – Please provide examples of other case studies For each example include 1. Location and background 2. Air quality conditions 3. Weather situation (surface, upper-air, stability, winds, etc. ) 4. Summary of episode (air quality and meteorology) 3. Case study examples 1. Ozone episode 2. PM 2. 5 episode 3. PM 10 episode (done) 4. CO episode 5. Long-range transport episode 6. Multi-pollutant episode 7. Smoke episode Section 11 – Case Study of Episodes 15

AREP GURME Case Study of Ozone Episode ● ● Location and background Air quality

AREP GURME Case Study of Ozone Episode ● ● Location and background Air quality conditions Weather situation Summary of episode (air quality and meteorology) Section 11 – Case Study of Episodes 16

AREP GURME Case Study of Ozone Episode n n Youngstown, Ohio, USA Summer 2002

AREP GURME Case Study of Ozone Episode n n Youngstown, Ohio, USA Summer 2002 Section 11 – Case Study of Episodes 17

AREP GURME Case Study of Ozone Episode 9 -11 June 2002 Episode 160 Youngstown

AREP GURME Case Study of Ozone Episode 9 -11 June 2002 Episode 160 Youngstown Regional 8 -hr O 3 Maximum AQI 140 120 100 80 60 40 20 0 * * 13 un L un -J -J 13 Jun 11 07 10 12 thth 12: 00 pm pm EST Jun 09 08 12 H un H H L L H HH -J un -J n Surface Pressure (msl) L * * 11 10 Ju 9 - n Ju 8 - 7 - 500 -mb Heights * * * 24 -hr Backward Trajectory L H HH H Section 11 – Case Study of Episodes 18

AREP GURME Case Study of Ozone Episode * * 500 -mb Heights Youngstown Regional

AREP GURME Case Study of Ozone Episode * * 500 -mb Heights Youngstown Regional 8 -hr O 3 Maximum * * * 24 -hr Backward Trajectory Surface Pressure (msl) L H H H Section 11 – Case Study of Episodes Jul 08 07 09 10 06 thth 12: 00 pm pm EST 19

AREP GURME Summary of Ozone Episodes Episode characteristics • Ridge of high pressure created

AREP GURME Summary of Ozone Episodes Episode characteristics • Ridge of high pressure created high pressure system • Recirculation was important for the 9 -11 June and July 8, 2002 • Episodes occurred on weekdays, which typically have higher emission patterns • Trajectories are useful for diagnosing air movement • Transport of ozone from upwind regions contributed to the ozone on 11 June 2002 Section 11 – Case Study of Episodes 20

AREP GURME Case Study of Ozone Episode in Sydney, Australia ● Ozone episode AUSTRALIA

AREP GURME Case Study of Ozone Episode in Sydney, Australia ● Ozone episode AUSTRALIA SYDNEY Section 11 – Case Study of Episodes 21

AREP GURME Eg: Syndey O 3 Event Dec 1998 Section 11 – Case Study

AREP GURME Eg: Syndey O 3 Event Dec 1998 Section 11 – Case Study of Episodes 22

AREP GURME Case Study of Smoke Episode in Melbourne, Australia ● Smoke episode AUSTRALIA

AREP GURME Case Study of Smoke Episode in Melbourne, Australia ● Smoke episode AUSTRALIA MELBOURNE Section 11 – Case Study of Episodes 23

AREP GURME Case Study of Smoke Episode in Melbourne, Australia Section 11 – Case

AREP GURME Case Study of Smoke Episode in Melbourne, Australia Section 11 – Case Study of Episodes 24

AREP GURME Case Study of Smoke Episode in Melbourne, Australia Visible satellite image and

AREP GURME Case Study of Smoke Episode in Melbourne, Australia Visible satellite image and modeled smoke Section 11 – Case Study of Episodes 25

AREP GURME How to Conduct Case Studies 1. Select a few air quality episodes

AREP GURME How to Conduct Case Studies 1. Select a few air quality episodes to study 1. Include ramp-up and cleanout days 2. 3. 4. 5. 6. 7. Review locations, magnitude, and duration of poor air quality Review surface and upper-air weather patterns Create backward trajectories to estimate transport Estimate upwind air quality to quantify local versus background contributions Review the temperature soundings to estimate vertical mixing Summarize the important processes that produced the episode Section 11 – Case Study of Episodes 26