We focus on a regional analysis of equatorial components of the effective atmospheric angular momentum (EAAM) functions that measure the excitation of polar motion. These functions are computed from National Centers for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR) reanalysis data both globally and in 108 geographic sectors for the period 1968--1997. We investigate the relationship between the regional sector EAAM and the global functions responsible for polar motion excitation. We examine two excitation terms in parallel, with and without the inverted barometer (IB) approximation, which adjusts the atmosphere to account for an isostatic equilibrium response of the ocean to overlying pressure. In the case of pressure terms without IB the largest contributions to the equatorial components of polar motion excitation functions originate in the South Pacific, North Atlantic, and North Pacific regions. Applying the IB correction results in the dominance of Eurasia and North America instead, with nearly all Southern Hemisphere contributions disappearing. When comparing the regional functions to their global sum, such fluctuations are mainly coherent with variations over northern midlatitude land areas. In some sectors, oscillations in these functions tend to occur broadly across two frequency bands: 25--75 and 75--125 days in both prograde and retrograde directions, corresponding to counterclockwise and clockwise polar motion, respectively. Other sectors contain more continuous spectral bands, which are centered at ~70 days. Coherence and cross-spectral analyses lead us to identify a region over Eurasia that contributes importantly to exciting polar motion; we also note an eastwardly propagating signal toward this region in these excitation terms. ¿ 1999 American Geophysical Union