Three‐dimensional tracer initialization and general diagnostics using equivalent PV latitude–potential‐temperature coordinates

This paper describes a simple, but effective, procedure for producing three‐dimensional tracer fields and general diagnostics based on an equivalent PV latitude–potential‐temperature coordinate system. The tracer fields generated by this method are shown to agree quantitatively with independently measured profiles and total columns. Using this initialization makes short model simulations of around a week or so much more realistic. It can be used to assimilate non‐global measurements, such as sonde or solar‐occultation satellite data, or to transform two‐dimensional model data into three‐dimensional fields.