Dynamics and Chemistry of the Upper Troposphere and Lower Stratosphere
Tropopause folds are intense synoptic-scale events thats transport air from the stratosphere into the troposphere.
This figures shows a large tropopause fold over the Colorado Rockies that was observed by the NCAR/NSF Gulfstream V research aircraft during the START08 project.
The Gulfstream V aircraft provided detailed chemical measurements of this event that are revealing much about the dynamical processes that control the chemical composition of the upper troposphere and lower stratosphere.
The time lapse movie below shows one flight by the Gulfstream V during START08 as seen from a camera mounted on the right wing of the aircraft. The white object in the lower left corner of the frame is the Microwave Temperature Profiler, which is mounted on the wing next to the camera. On the upper left side of the frame you can see the nose of the aircraft with the NSF logo. Some parts of the video have been edited out, so the six and a half hour flight can be seen in less than 4 minutes.
During this flight the aircraft took off from Broomfield, CO, which is just west of Denver. After flying eastward at low altitude over eastern Colorado, the plane climbed into the lower stratosphere. It then descended through low stratus clouds and executed a missed approach at the airport at Ponca City, OK. You can just glimpse the runway through the water and ice on the camera lens. After climbing back into the stratosphere the plane flew around a squall line in eastern Oklahoma before executing a second missed approach at Alexandria, LA. Climbing once again into the stratosphere the plane continued south over New Orleans, LA and made a low pass over the Gulf of Mexico. The return flight to Colorado was primarily in the upper troposphere and lower stratosphere. The aircraft reached a maximum altitude of over 47,000 feet before descending through clouds to land at Broomfield.