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Christopher W. Hughes
Peter D. Killworth


The characteristics of an unforced, stratified f-plane geostrophic flow over topography are described, and scaling arguments are made to justify the use of such a flow as a first-order approximation to a real, large-scale circulation. Consideration of integral constraints then provides an insight into the ways in which second-order processes must balance the wind forcing. The importance of bottom pressure in this model is used to test the scalings and theory on a dataset taken from the Fine Resolution Antarctic Model. Two plots of bottom pressure, each with depth dependence filtered out in a different way, confirm the scalings producing the following conclusions: The effect of topography on the bottom boundary condition (no flow through the boundary) is important to the first-order (f-plane geostrophic) circulation; the turning of horizontal velocities with depth is limited, especially in regions of strong flow; and a picture of bottom pressure, appropriately filtered for depth dependence, contains a wealth of valuable information about the importance of second-order processes, demonstrating that they are most important in particular localized regions associated with topographic features.

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Mark A. Shafer
Christopher A. Fiebrich
Derek S. Arndt
Sherman E. Fredrickson
, and
Timothy W. Hughes


High quality data sources are critical to scientists, engineers, and decision makers alike. The models that scientists develop and test with quality-assured data eventually become used by a wider community, from policy makers’ long-term strategies based upon weather and climate predictions to emergency managers’ decisions to deploy response crews. The process of developing high quality data in one network, the Oklahoma Mesonetwork (Mesonet) is detailed in this manuscript.

The Oklahoma Mesonet quality-assurance procedures consist of four principal components: an instrument laboratory, field visits, automated computer routines, and manual inspection. The instrument laboratory ensures that all sensors that are deployed in the network measure up to high standards established by the Mesonet Steering Committee. Routine and emergency field visits provide a manual inspection of the performance of the sensors and replacement as necessary. Automated computer routines monitor data each day, set data flags as appropriate, and alert personnel of potential errors in the data. Manual inspection provides human judgment to the process, catching subtle errors that automated techniques may miss.

The quality-assurance (QA) process is tied together through efficient communication links. A QA manager serves as the conduit through whom all questions concerning data quality flow. The QA manager receives daily reports from the automated system, issues trouble tickets to guide the technicians in the field, and issues summary reports to the broader community of data users. Technicians and other Mesonet staff remain in contact through cellular communications, pagers, and the World Wide Web. Together, these means of communication provide a seamless system: from identifying suspicious data, to field investigations, to feedback on action taken by the technician.

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