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Download Warm air intrusions in Arizona`s Meteor Crater
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SUBMITTED FOR ORAL PRESENTATION Warm air intrusions in Arizona’s Meteor Crater – evidence for hydraulic jumps? Bianca Adler1, C. David Whiteman1, Sebastian W. Hoch1, Manuela Lehner1 and Norbert Kalthoff2 1University of Utah, 2University of Karlsruhe Episodic intrusions of warm air, accompanied by strong winds, enter the enclosed near-‐circular Barringer Meteorite Crater basin during clear, synoptically undisturbed nights. These warm air intrusions remain confined mainly[?] above the surface in the lee of the crater's upwind rim. Using data from the 2006 METCRAX (Meteor Crater Experiment) field study we determined the spatial and temporal characteristics of the warm air intrusions, their effects on the atmospheric structure inside the crater, and their relationship to larger-‐scale flows and atmospheric stability. The warm air intrusions appear to be produced by small-‐scale atmospheric hydraulic jumps. The intermittent warm air intrusions are associated with near-‐continuous shallow cold-‐air intrusions that come over the upwind crater rim during synoptically undisturbed nights, descend into the crater on the upwind inner sidewall, and destabilize the crater atmosphere. The cold air inflow is a result of the evolution of a stable surface layer and a regional-‐scale southwesterly drainage flow on the inclined plain outside the crater. Occasional instabilities occur in the flow coming over the crater rim, which extends 50 m above the surrounding plain, causing warm air from above the inversion on the surrounding plain to descend up to 140 m into the 170-‐m-‐deep crater. This warm air intrusion does not destroy the shallow cold air inflow on the slope below it, does not reach the crater floor, and does not extend into the center of the crater, where the nighttime stable layer in the remainder of the crater volume remains largely undisturbed. New field experiments and model simulations are suggested to test the hypothesis that the warm air intrusions are hydraulic flows.
