| Abstract: | Oceanography is necessarily a three-dimensional science, for the open surface of the sea conceals tremendous variations in depth and marked differences in temperature, salinity, and water movement, all of which are critical for marine life. Today the major research programmes study the oceans in four dimensions, since changes with time—daily, seasonal, and year-to-year—are no less important than those in space. Oceanography and meteorology have much in common: the temperature and movement of air and water cannot be directly seen from the ground or sea level, but must be investigated by means of specialised instruments whose readings can be brought back to the observer. |
