This "sounding" was made using the height & temperature information available to passengers on jets with map screens. In this case, the information was collected while flying a Boeing 777 (United flight 929) on approach to Chicago's O'Hare Airport (ORD) on 6 February 2001.

The raw data (below) indicates relatively homogeneous conditions across the region of descent, which is why the observations are considered a vertical sounding even though the plane was flying approximately 200 mph.

	Temperature vs. height
	Approximate flight path
Height Temperature [m] [oC] 7010.0 -40.000 6705.0 -38.000 5307.0 -30.000 4770.0 -25.000 3661.0 -17.000 3546.0 -16.000 3353.0 -15.000 3353.0 -15.000 3359.0 -15.000 3354.0 -15.000 3048.0 -12.000 3048.0 -12.000 3046.0 -11.000 2916.0 -10.000 2509.0 -8.000 2133.0 -7.000 1844.0 -6.000 1526.0 -4.000 1524.0 -4.000 976.00 -2.000 619.00 -2.000 400.00 0.000 180.00 3.000	Data collected 6 February 2001 from about 1320 - 1345 CST on approach to ORD. Plane traveling about 200 mph from NE (across Lake Michigan to ORD). Observations about 1 minute apart.

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