Influence of a tropical cyclone on the upper ionosphere according to tomography sounding data over Sakhalin Island in November 2007

Abstract

Tomography sounding data for the first half of November 2007 are presented. The sounding was conducted over three points located at the same meridian—Yuzhno-Sakhalinsk (47° N, 143° E), Poronaisk (49° N, 143° E), and Nogliki (51° N, 143° E)—in order to find the possible influence of a tropical cyclone on the upper ionosphere. A change in the foF 2 parameter by on average no more than 10–20% is a possible response of the upper ionosphere localized over the tropical cyclone (TC) zone (in the given case, 25°–30° northward and 5°–20° eastward) at a distance of approximately 3800–5500 km from it. A decrease or, vice versa, an increase in foF 2 is related to the delay of the measurement moment relative to the beginning of the TC action. The complexity of a morphological analysis of the given event is that a tropical cyclone is a “wideband” (in the longitudinal and, to a lesser degree, in the latitudinal directions) and lasting disturbance source.