Arecibo observations of ionospheric perturbations associated with the passage of Tropical Storm Odette

Abstract

A suite of instruments including incoherent scatter radar, ionosonde, and a satellite-bourne GPS receiver observed the ionosphere immediately following the passage of a tropical storm. Tropical Storm Odette formed on 4 December 2003 and proceeded northeasterly over the next 4 days, passing within 600 km of the Arecibo Observatory (AO). On the night of 7-8 December AO measured F region plasma densities and velocities nearly coincident with the storm. Large velocity variations, 10-80 m/s, are evident in the plasma drift components. The variations appear wave-like with an average period of 90 min at 367 km. Zonal drifts were observed with magnitudes significantly greater than commonly observed for similar geomagnetic conditions. The Ramey ionosonde observed intense midlatitude spread F on the night following the closest passage of the storm. GPS occultations within the storm path showed an increase in gravity wave activity and F region scintillation. Combining the local increase in gravity wave activity with the large drift variations and dominant meridional electric field observed immediately following the storm's traversal of the flux tube coincident with the AO observing volume provide insight into coupling between mesoscale weather systems and the ionosphere. Copyright 2006 by the American Geophysical Union.