Page:Popular Science Monthly Volume 9.djvu/322

300 meets with the cold current from the north, it slopes upward over the cooler current, and forms stripes or bands of stratus clouds along the horizon, as shown in Fig. 3.



These stratus clouds indicate to the observer the fact that a warm current is coming northward.

When in summer a cool current is moving southward, it encounters the warm equatorial or tropical current, which again glides upward and over it, and forms horizontal bands of stratus clouds along the upper line of contact, as in winter storms; but, in addition, the denser cold air from the north, moving with more momentum, will lift up the warm and saturated air from the tropics, and its moisture