Séminaire
Using the wavelet phase/coherence technique, I analyze the geographical distribution of the air-surface temperature response to external (solar, volcanic and geomagnetic) forcing on the periods of 11 and 22 years for the most of the 20th century. I show the existence of a combined forcing of solar and volcanic activity on the Earth temperature on the 11-year period in the second half of the 20th century over the globe, whereas a set of stations (mostly in North Atlantic) demonstrates a response to solar activity even in absence of the combined effect. I illustrate that the mostly widespread response is to geomagnetic activity on the 22-year period during the time interval without intensive volcanic eruptions with considerable atmospherical consequences. In addition, I present a case study of the effect of different climatic forcings on century-long monthly series of temperature parameters measured by three Portuguese meteorological stations, using various statistical methods.