Abstract: Utilizing GPS sounding data collected during the Surface Heat Budget of the Arctic Ocean campaign over the period of one year (SHEBA, October 1997-October 1998), the authors characterized the boundary layer inversion and low-level jet over the Arctic Ocean. The results showed that 96% of the soundings (1115 UTC and 2315 UTC) had near-surface inversion layers, where 22% were surface-based and 70% were between 250 m and 850 m. During the winter months, the frequency of the surface-based inversion, the inversion depth, and the temperature change in the inversion layer were stronger than that during the summer months. During the year, the low-level jets occurred with a frequency of 41% and their average height was 520 m. The jets appeared mostly around 150 m, and 70% were below 600 m. The mean speed of the jets was 10.6 m·s^-1 and the predominant wind direction was east and northeast; 75% of the wind speeds recorded ranged between 4 m·s^-1 and 13 m·s^-1. The analysis of the turning angle distribution between the jet core and the ground wind indicated that inertial oscillation was the main cause of the low-level jet in the Arctic region.