Asymmetry of the Intertropical Convergence Zone Asymmetry of the Intertropical Convergence Zone There are a number of explanations of the asymmetry of the Intertropical Convergence Zone (ITCZ), known by sailors as The Doldrums. The ITCZ would be expected to overlie the geographic equator according to symmetric solar radiation. However, the ITCZ is mostly perennial in the northern hemisphere and in the eastern Pacific and Atlantic Oceans. It was originally explained by the asymmetrical distribution of continents. However, the distribution of land and ocean is severely asymmetric in the Indian Ocean, yet the ITCZ moves back and forth there between the southern and northern hemispheres. Continents surround
Tropical cyclone starts to develop, although an eye is not usually present. Government weather services first assign names to systems that reach this intensity (thus the term "named storm"). Although tropical storms are less intense than a hurricane they can produce significant damage. The shear force of winds can blow off shingles, and air borne objects can cause damage to power lines, roofing and siding. More dangerous is the heavy rainfall causing inland flooding. A hurricane or typhoon (sometimes simply referred to as a tropical cyclone, as opposed to a depression or storm) is a system with sustained winds of at least