Method: For this purpose, foF2 data from four Antarctic stations were analyzed during three intense magnetic storms occurred in high solar activity (years 2002 and 2003). In general, negative storm effects irrespective of the local time were observed during the first part of the storms (main phase). Negative effects were also observed more often than positive effects during the first part of th...

Bayesian statistical models were developed for the number of tropical cyclones and the rate at which these cyclones became hurricanes in the North Atlantic. We find that, controlling for the cold tongue index and the North Atlantic oscillation index, there is high probability that the number of cyclones has increased in the past thirty years; but the rate at which these storms become hurricanes...

[1] We introduce a technique for assessing the diurnal development of convective storm systems based on outgoing longwave radiation fields. Using the size distribution of the storms measured from a series of images, we generate an array in the length scale‐time domain based on the standard score statistic. It demonstrates succinctly the size evolution of storms as well as the dissipation kinema...

Introduction: Many local dust storms have been observed near the polar cap edges [1]. Some local dust storms near the polar cap edges grew into a global dust storm [2,3]. Using a GCM, [4] showed that dust artificially injected into the atmosphere near the southern cap edge in the southwest Hellas Basin moved to the north along the western inner rim of the basin. This movement of dust simulated ...

We study the annual frequency of occurrence of intense geomagnetic storms (Dst < )100 nT) throughout the solar activity cycle for the last three cycles and ®nd that it shows di€erent structures. In cycles 20 and 22 it peaks during the ascending phase, near sunspot maximum. During cycle 21, however, there is one peak in the ascending phase and a second, higher, peak in the descending phase separ...