Upper-air sounding data collected at Santa Cruz (10 ¿S, 165 ¿E) in the western tropical Pacific Ocean during November 1992--February 1993 have been used to estimate the gravity wave activity in the upper troposphere and lower stratosphere. Large amplitude gravity waves with vertical wavelengths of 2--5 km were found in almost all the soundings. Time series describing the wave activity in two height ranges, 10--17 km (the upper troposphere) and 17--24 km (the lower stratosphere) are presented and compared to simple measures of the convective cloud activity. There is enhanced gravity wave activity associated with increased convection on intraseasonal timescales. ¿ American Geophysical Union 1996