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Investigating Ozone Sources in California Using AJAX Airborne Measurements and Models: Implications for Stratospheric Intrusion and Long Range TransportHigh ozone concentrations at low altitudes near the surface were detected from airborne Alpha Jet Atmospheric eXperiment (AJAX) measurements on May 30, 2012. We investigate the causes of the elevated ozone concentrations using the airborne measurements and various models. GEOSchem and WRF-STILT model simulations show that the contribution from local sources is small. From MERRA reanalysis, it is found that high potential vorticity (PV) is observed at low altitudes. This high PV appears to be only partially coming through the stratospheric intrusions because the air inside the high PV region is moist, which shows that mixing appears to be enhanced in the low altitudes. Considering that diabatic heating can also produce high PV in the lower troposphere, high ozone is partially coming through stratospheric intrusion, but this cannot explain the whole ozone concentration in the target areas of the western U.S. A back-trajectory model is utilized to see where the air masses originated. The air masses of the target areas came from the lower stratosphere (LS), upper (UT), mid- (MT), and lower troposphere (LT). The relative number of trajectories coming from LS and UT is low (7.7% and 7.6%, respectively) compared to that from LT (64.1%), but the relative ozone concentration coming from LS and UT is high (38.4% and 20.95%, respectively) compared to that from LT (17.7%). The air mass coming from LT appears to be mostly coming from Asia. Q diagnostics show that there is sufficient mixing along the trajectory to indicate that ozone from the different origins is mixed and transported to the western U.S. This study shows that high ozone concentrations can be detected by airborne measurements, which can be analyzed by integrated platforms such as models, reanalysis, and satellite data.
Document ID
20160011455
Acquisition Source
Ames Research Center
Document Type
Presentation
Authors
Ryoo, Ju-Mee
(Universities Space Research Association Moffett Field, CA, United States)
Johnson, Matthew S.
(NASA Ames Research Center Moffett Field, CA United States)
Iraci, Laura T.
(NASA Ames Research Center Moffett Field, CA United States)
Yates, Emma L.
(Bay Area Environmental Research Inst. Moffett Field, CA, United States)
Pierce, R. Bradley
(National Oceanic and Atmospheric Administration Madison, WI, United States)
Tanaka, Tomoaki
(Bay Area Environmental Research Inst. Moffett Field, CA, United States)
Gore, Warren
(NASA Ames Research Center Moffett Field, CA United States)
Date Acquired
September 26, 2016
Publication Date
February 10, 2016
Subject Category
Geosciences (General)
Report/Patent Number
ARC-E-DAA-TN29721
Meeting Information
Meeting: Earth Science Division Poster Session
Location: Moffett Field, CA
Country: United States
Start Date: February 10, 2016
Sponsors: NASA Ames Research Center
Funding Number(s)
CONTRACT_GRANT: NNX12AD05A
CONTRACT_GRANT: NNH15CO48B
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
gas composition
low altitude
ozone
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