Wahr, J. M., and A. H. Oort, 1984: Friction- and mountain-torque estimates from global atmospheric data. Journal of the Atmospheric Sciences, 41 (2), 190-204.

Abstract: Seasonal, zonal surface torques between the atmosphere and the Earth are estimated and compared by using data from a number of independent sources. The mountain torque is computed both from surface pressure data and from isobaric height data. The friction torque is estimated from the oceanic stress data of Hellerman and Rosenstein. Results for the total torque are inferred from atmospheric angular momentum data. The globally integrated total torque is compared with astronomical observations of the Earth's rotation rate. These comparisons help to assess the quality of the different results.
Zonal torques are also computed by using results from a GFDL general circulation model of the atmosphere. A comparison with the corresponding results inferred from real data is presented and interpreted in terms of model accuracy.