Research on Surface Weather Map Analysis

Sanders, Frederick, Marblehead MA

Investigators

Abstract

Accurate and objective methods for diagnosis of surface frontal features is important to meteorological education, research and operations. The goal of this project is to develop and validate a technique of surface map analysis that differs from present practice. Current analysis practice places excessive reliance on the polar front theory. This project plans to show that many, if not most, fronts now routinely shown on maps and used as the basis for understanding the weather pattern are lacking evidence for a quasi-discontinuity of density that is required for relevance to polar front concepts. Instead, the Principal Investigator proposes: (1) to restrict identification of fronts to the occasional structures that do adhere closely to the theory; (2) to establish the importance of zones of pronounced horizontal temperature gradient lacking a sharp frontal wind shift at the warm edge, which are not now recognized in current practice; (3) to encourage denoting many of the structures now falsely designated as fronts instead as troughs of low pressure. It is expected that the project will lead to improved understanding of processes in the surface boundary layer as well as in the free atmosphere above. The research will rely on the database of routine surface observations. Issues to be addressed are the relationships between the boundary-layer structures and synoptic-scale cyclogenesis, and the process of frontogenesis. The research will develop the idea of frontogenesis as a two-stage process in which first a zone of relatively strong horizontal temperature gradient is created, and then this zone is acted upon by short-lived exposure to deformation and/or convergence. Successful completion of this research will result in changing the way surface map analysis is done and in providing a physically realistic way of explaining weather phenomena of various types.