11.3 The impact of asymmetric solar heating on the cross-basin circulation in Arizona's Meteor Crater

Thursday, 2 September 2010: 8:30 AM
Alpine Ballroom A (Resort at Squaw Creek)
Manuela Lehner, University of Utah, Salt Lake City, UT; and C. D. Whiteman and S. W. Hoch

Cross-basin winds are produced in Arizona's Meteor Crater by asymmetric heating of the crater sidewalls. Observations made during the Meteor Crater Experiment (METCRAX) reveal the presence of a cross-basin flow above the crater floor during clear-sky days. The cross-basin flow exhibits a pronounced diurnal cycle, with particularly strong wind components associated with asymmetric heating during the morning and evening transition periods. Winds shift continuously from an easterly direction in the morning to a southerly direction around noon and finally, to a westerly direction in the evening.

A one-month dataset from the METCRAX field campaign is used to show how the cross-basin flows relate to asymmetries in solar irradiation between opposing crater sidewalls. Asymmetric insolation between the sun-facing and the opposite, less sunlit or shaded sidewall produces a temperature and pressure gradient across the basin, whose direction changes gradually during the day as the sun moves from east to west. The pressure gradient force leads to the formation of cross-basin winds at the crater floor, blowing from the shaded sidewall towards the sunlit sidewall.

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