Long-term course of cloud genera frequency in Cracow (1906–2000)



The studies on the contemporary climate fluctuations seldom analyze the multi-annual qualitative changes of cloudiness, although many authors emphasize the necessity of undertaking nephological research which is indispensable to know, model, and monitor the climate. There are hypotheses that in various regions of the world an increase of frequency of occurrence of certain cloud genera (Ci, Ac, Sc, Cu, and Cb) and a decrease of frequency of other genera (Cc, Cs, Ns, St, and fog) takes place.