Parti

cle

Amou

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o Our model results indicate that a 3-day (Aug. 26-28) blocking high over the SE-US enhanced the 4-8 km O3 layer by ~30 ppb. As the high moved west (Aug. 30), subsiding air over the central plains began to mix with polluted air traveling from the Northwest, enhancing the 8-11 km layer over STL and UAH by ~50 ppb. The remaining polluted air was advected out by Aug. 31st.

o A synoptic scale feature is found to be the driving force behind widespread O3 enhancements over the SE-US over the time period. Observations from the UAH O3 Dial and the ozonesondes both captured the multi-site disturbance.

o Future work, includes investigating past ozonesonde data for common features at multiple sites. Three SEACIONS sites have 10-plus year records: Houston, Boulder, and Huntsville. To further validate our claims, we will use the NASA SEAC4Rs mission DC-8 data to distinguish chemical tracers inside the plumes.

Joseph L. Wilkins1, Gary A. Morris2, Jack Fishman1, Benjamin de Foy1 , Charles Graves1 , Mike Newchurch3, Shi Kuang3, Ed Hyer4, and Anne M. Thompson5

1.Saint Louis University , 2.Valparaiso University3. U. of Alabama-Huntsville 4. Naval research lab 5. NASA GSFC / Penn State

AcknowledgmentsThis work was supported in part from NASA Grant NNX11AJ63G to Saint Louis University through its AQAST Program. A special thanks to data providers: FLAMBE Provided by: Ed Hyer, and UAH for the O3 Lidar.

Summary

An Analysis of SEACIONS Ozonesonde St. Louis, MO. Site in August-September 2013: Insight into the Influences of Wildfires and Strat-Trop Exchange on Midwest Regional Air Quality

1. Prelaunch

SEAC4RS SCIENCE TEAM MEETING Pasadena, CA APR. 28- MAY 1, 2015

2. Observations

o Using FLAMBE hourly emissions, 4 day forward trajectories were ran from FLEXPART-WRF. o High Pressure advected particles around the Central US to the SE-USo FLEXPART-WRF trajectories overlapped with areas effected by UT/LS sinking air linking a

Strat-intrusion to O3 plume enhancement captured by an STL Sonde AUG 30th . o FLEXPART Runs: NARR data, 4-km WRF grid, hourly temporal resolution.

o The SouthEast American Consortium for Intensive Ozone Network Study (SEACIONS) mission consisted of concurrent ozonesonde launches from St. Louis, MO and six other locations across the South Eastern U.S. (SE-US), between Aug. 8 and Sept. 23 2013 (see Fig. 1).

o Primary science objectives: 1. Investigate convective and wave signatures in ozone (O3) profiles 2. Further explore the interaction of urban pollution and pyro-convection transport.

o To interpret our STL observations, we used an O3 Lidar from Huntsville, AL; trajectory calculations from the NASA GSFC, and FLEXPART-WRF models; for fire detection the Fire Locating And Modeling of Burning Emissions (FLAMBE).

o During SEACIONS several sources of elevated O3 were detected. Aug. 26-30 there was a case of a blocking high pressure showing enhanced O3 at all sites from three potential sources: Pollution from wildfires out west, SE-US agricultural fires, and subsiding air from the Upper Troposphere and Lower Stratosphere (UT/LS).

Discussion

Contact Author: jwilkin9@slu.edu

FLAMBE Fires During High Pressure Week

Fig. 3: FLAMBE large fires Aug. 26-30. All FLAMBE emissions were gridded to a 2.5° x 2.5° grid then used as input into the FLEXPART-WRF model.

Idaho Beaver Creek (43 98’ N, 112 23’ W)

Ag. FiresCalifornia RIM Fire(37 51’ N, 120 05’ W)

STL

FLAMBE system uses active fire detection from GOES WF_ABBA and MODIS to detect biomass burning activity near real time.o Wildfires:

- Idaho’s Beaver Creek (~115 K acres started 8/7/13 by lightning) - California’s RIM fire (~258 k acres, started 8/17/13 by camp fire)

o Misc:- widespread agricultural fires in the Midwest were taking place

On August 30, 2013 mixing between UT/LS air and a biomass burning plume at the 8-11km layer was

captured by an STL OzoneSonde

o A high pressure system developed on Aug. 25 over the SE-US, reaching its max on the 26th, leading to subsiding air and weak flow in the south central US.

o A weak frontal passage forced the high’s core westward on Aug. 29, allowing air to circulate in from the north and west.

Meteorology

Fig. 2: NARR 500 mb Aug. 30 at 18Z, NARR PVU in blue, Pressure in black, Shaded is RH<30%.

Fig. 1

3. FLEXPART-WRF Simulations Using FLAMBE

Fig. 7: FLEXPART-WRF forward trajectories, AUG 26, 2013; 4-day forward trajectories from the major locations identified from FLAMBE. Particle released amounts per day can be seen in Fig. 8.

What Does the Observations During SEACIONS Show Us?

Fig. 6: Aug. 30 Sonde: O3 (red) and RH (green), STL O3 mean (black), showing multiple trop enhancements.

Plume 1 [5-7 km]: 5-7 km-> O3: 90 ppb & RH: ~10% Plume 2 [8-11 km]: 8-9 km-> O3: 110 ppb & RH: ~25% 10-11 km-> O3: 135 ppb & RH: >10%

3. Stratified layers inside the STL Ozonesonde profile are present because of subsiding ozone rich

strat air and ascending clean trop air due to the high pressure

Fig. 5: Aug. 30 at 18Z NARR PVU (blue), RH (<30% shaded), and potential temp (black), cross sections. A) shows the cross section locations. B) 90W; 35-50N and C) 110W-85; 37N.

90W;35-50N

Rising trop airDescending strat air

110W-85; 37N

Descending strat air

90ppb at 500hPa

130ppb at 280hPa

Fires+Nox

Clean air

Clean air

Stratospheric+Wildfires

o Inside the mixed layer height (<2 km): STL has a 20 ppb enhancement

o All site exhibit similar enhancement between 3-7 km 0.09 ppmv (90 ppb)

o Above 7 km, Boulder (BCO) and Houston (ETX) O3 is ~50 ppb greater than other sites.

Fig. 4: UAH O3 DIAL, O3 Lidar measurement at Huntsville, AL summer 2013 during the SEACIONS mission. There is an enhanced layer at ~5 km observed Aug. 27-28, and at 5-8 km on Aug. 30.

8/27

UAH 8/27 sonde

UAH 8/28 sonde

8/28 8/30

UAH 8/30 sonde

90+ ppb 4-7km 5-7km layer

cleaner air

1. A synoptic feature caused Multi-site O3 enhancement

Fig 3: Ozonesonde profiles from locations in Fig.1. Sonde profiles below 10 km, all having enhancement between 5-7km layer

OzoneSonde Launches B

RegionalAg. Firesinfluenced

Mixed Layerheight

+50ppb

C

Fig. 8: Model forward simulation count of particles launched in FLEXPART-WRF simulation. The start times for the large

wild fires can be identified as large spikes inside the dataset. 1 FLEXPART Particle = 100kg of FLAMBE emissions

Fig. 9: Curtain plots for AUG; A) trajectory overpasses over STL within a 2.5° x 2.5° grid, each point is binned daily per 500m, and B) STL ozonesonde launches. Black Circles indicate no fires influence high Ozone, Red Circles indicates influence.

Fig. 10: On Aug. 30th, 2013 a STL OzoneSonde captured a dual enhancement of O3: 45ppb at 8-11km and 20ppb at 5-7km (black curve). NARR and NASA-GSFC high-res kinematic model depict a Strat-Trop exchange at the 8 km layer (red curve), and FLEXPART-WRF forward trajectories indicate an enhancement due to fires at the 10km (blue curve).

Idaho Fires started 8/7/13

RIM Fire started 8/17/13

The start times of large emission sources can be identified from the FLEXPART hourly particle

releases (Fig. 8)

The SEACIONS network shows a week long enhancement between the 5-7km layer, captured by the UAH O3 DIAL and ozondeSondes. The exact cause of that layer is currently unknown, it appears to be created by stagnation and/or convective processes caused during the week long high pressure system. This may the be due to anthropogenic emissions. Cooper et al 2007 and others have stated that there is a reoccurring layer of elevated O3 over the SE-US during anticyclonic flow, which is typical summertime flow. This finding appears to be supported by the SEACIONS network, as shown on AUG 28 in Fig. 3. The western sites outside of this phenomenon appear to steadily increase aloft as oppose to the other sites which have a sharp decline.

2. During SEACIONS a persistent mid-level elevated O3 layer is captured by UAH O3 DIAL and Sondes

o A deep tropopause fold to 700 mb on the eastern edge of the high. o The 2 day fold moved eastward by Aug. 30 bringing down UT/LS air.

So What Happened at 5-7 km?

Conclusions

37N

90W8/30

A

B

A

B

STL8/30 sonde