Objective Analysis of ARM IOP Data: Method and Sensitivity

Abstract

Motivated by the need to obtain accurate objective analysis of field experimental data to force physical parameterizations in numerical models, this paper first reviews the existing objective analysis methods and interpolation schemes that are used to derive atmospheric wind divergence, vertical velocity, and advective tendencies. Advantages and disadvantages of different methods are discussed. It is shown that considerable uncertainties in the analyzed products can result from the use of different analysis. The paper then describes a hybrid approach to combine the strengths of the regular grid and the line-integral methods, together with a variational constraining procedure for the analysis of field experimental data. In addition to the use of upperair data, measurements at the surface and at the top of the atmosphere (TOA) are used to constrain the upperair analysis to conserve column-integrated mass, water, energy, and momentum.