Gridded fields of horizontal and vertical winds, temperature and height are objectively calculated for regions encompassing a major wintertime storm which developed during the Air-Mass Transformation Experiment (AMTEX) 1975.
The objective analysis, the Pattern Conserving Technique (PCT), used to obtain the gridded fields was developed within the framework of the calculus of variations. PCT, through the application of several variational constraints such as proposed by Sasaki (1970) and implemented by Baxter (1975), simulates the thought processes and subjective analysis techniques of the human analyst. The analyses fields are further refined by including physical constraints which minimize inertial instability, satisfy hydrostatic balance and insure for mass continuity.
From the resulting horizontal wind analyses, vertical motion fields are computed using the kinematic method and are verified for representativeness by subjectively comparing them with synoptic features such as fronts, precipitation reports, cloud analyses, and satellite photographs obtained from the U.S. Air Force Global Weather Central (AFGWC). The vertical motion fields are also compared with those derived from the quasi-geostrophic omega equation as solved by the Japanese Meteorological Agency (JMA), and the AFGWC, and with vertical motions kinematically computed from subjectively analyzed horizontal winds. The results of the comparison show that the vertical motion fields obtained from PCT exhibit a marked improvement in representing the synoptic situation and related weather features.