Arrows indicate the annual exchange of water between these storages. The annual precipitation for the earth is more than 30 times the atmosphere's total capacity to hold water. This fact indicates the rapid recycling of water that must occur between the earth's surface and the atmosphere. Hair hygrometer Hair hygrometer is an instrument that indicates relative humidity, based on the expansion and contraction of a treated human hair. The length of a strand of human hair changes as a function of relative humidity.
Hair becomes longer with higher relative humidity and shorter with lower relative humidity.
On very humid days, your hair actually becomes longer. The fact that the length of hair changes with relative humidity is used in an instrument known as the hair hygrometer. This instrument uses strands of human or horse hair with the oils removed attached to levers that magnify a small change in hair length. The disadvantages of the hair hygrometer and hygrograph are that they are not as accurate as the psychrometer and frequent adjustment and calibration are required. The Coriolis force is a fictitious force exerted on a body when it moves in a rotating reference frame.