Abstract We present a novel approach to derive three‐dimensional Climatic Higher‐Order Balanced (CHOB) wind fields from thermodynamic state variables in the free troposphere and stratosphere. The CHOB method is developed for monthly synoptic‐scale wind field estimation, utilizing commonly used balanced winds (geostrophic and gradient wind) enhanced by incorporating higher‐order terms in the momentum equations. This new approach addresses limitations of geostrophic and gradient wind approximations in capturing zonally asymmetric mean flow, that is, advection effects. It enables the reconstruction of monthly wind fields from geopotential data by formulating higher‐order balances for the zonal and meridional wind component for the respective atmospheric layer. In this manner, part of the non‐linear components of the atmospheric circulation gets captured. The approach was implemented and tested using ERA5 reanalysis data over the period 1980–2020, with detailed case studies for January 2009 and 2014. Results demonstrate the robustness and consistency of the method for different atmospheric dynamic environments, including both calm conditions and periods of strong planetary wave activity. While validated using ERA5 reanalysis data, the methodology is applicable to a range of data sources, particularly for long‐term stable and high‐accuracy Global Navigation Satellite System radio occultation data, enabling the generation of an additional and complementary observation‐based 3D wind field record for climate monitoring and research.
Nimac et al. (Thu,) studied this question.