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WP-3D Daily Summaries

7/27/04 WP-3D Flight Summary (Preliminary Observations) Updated 01/19/2005

Take off: 15:03 UTC, Landing 22:26 UTC, flight duration 7 h 23 min

A cut off low at 500 mb formed on 7/26 over the Iowa/Illinois state-line and moved to the Michigan-Indiana state-line by 7/27 12 UTC. The associated surface low was centered over the Ohio-West Virginia-Kentucky border area on 7/26 and moved to the West Virginia-Pennsylvania state-line by 7/27 12 UTC. Along the surface cold front - which stretched from the center of the surface low to the SW along the Appalachian Mountains - precipitation in access of 1 inch was recorded on 26-28 July. For July 27, the Flexpart tracer model indicated a pollution ridge along the Appalachian Mountains roughly orientated along the surface front. The flight on 7/27 aimed to characterize the pollution accumulation ahead of the cold front, with the objective to follow the predicted pollution export along the front on the following day, 7/28.

The WP3 transited to southern PA at 4400 m within clouds where CO levels up to 120 ppbv indicated lifting of pollution. The P3 characterized the pollution upwind and downwind of the Washington, Baltimore metropolitan area. While the P3 encountered broken clouds over Virginia, a line of thunderstorms from Washington, DC to Philadelphia started to form around 17 UTC. This line of thunderstorms intensified and moved to the NE during the remainder of the flight. The presence of the severe storm cells led to adjustments in the flight pattern in and around the Philadelphia area and may allow to examine the signatures of the upward pollution transport by clouds near a major metropolitan area.

The highest CO values were seen over Virginia, where Flexpart analysis indicates flow from the SW and a source region from Virginia to the Carolinas. The NW to SE transect between Baltimore and Philadelphia was near the warm front, which is reflected in the boundary layer footprint region as analyzed with Flexpart. CO concentrations up to 180 ppbv show the influence of the emissions from Washington and Baltimore.

Over Massachusetts the WP3 encountered pollution at 4800 m (CO~1200 ppbv) and a very clean layer at 1600m (CO~72 ppbv).Flexpart analysis can qualitatively reproduce the different origin of these air masses.

Actual Flight Track:

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Flight Plan Map
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Flight Plan Lat/Lon Points
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