Diurnal oscillations in atmospheric pressure at twenty‐five small oceanic islands

The diurnal oscillation in atmospheric surface pressure—the S 1 ( p ) tide—is estimated at 25 oceanic stations. The estimated mean amplitudes and phases are compared to two theoretical predictions of the migrating S 1 component recently computed by Braswell and Lindzen and to the older wavenumber‐1 decomposition of Haurwitz and Cowley. The new S 1 amplitudes are weaker than the Haurwitz‐Cowley amplitudes everywhere, suggesting that their model may have been unduly influenced by nonmigrating components from continental stations. The observations show best agreement with a theoretical model having 25 W m −2 additional atmospheric energy absorption relative to that inferred from general circulation models. Stations polewards of the S 1 critical latitude are somewhat anomalous.