There's a Freshwater Ocean in the Air!

The global elemental water cycle (aka The Hydrologic Cycle) stores about 3.43 million billion US gallons of freshwater in the atmosphere at any point in time and precipitates the equivalent of 13 million billion US gallons of water on land every year


Our Sun is the Primary Driver of the Water Cycle

The Sun
Source - science.nationalgeographic.com

Freshwater in the atmosphere is water evaporated from land and oceans by the energy contained in sunlight.
Sunlight heats water on land and oceans causing some of it to evaporate into the atmosphere. 
Sunlight also creates air currents that raise the evaporated water vapor higher in the atmosphere and moves the water vapor using wind all over the globe.


Water Evaporation into the Air

Evaporation
Source - aboutcivil.com

Between 496,000 and 460,000 cubic kilometers of water evaporates every year into the atmosphere. 
Of this amount 70,000 -73,000 evaporates from land while 390,000-423,000 evaporates from the oceans every year.
Evaporation adds between 1,359 and 1,260 cubic km daily into the air = the addition of 358,800 - 332,700 billion US gallons of water a day
References:
Principles and Applications of Aquatic Chemistry,By François Morel, Janet G. Hering

Industry, Fresh Water and Sustainable Development, WBCSD & UNEP, 1998Water - Facts & Trends - Ver 2, World Business Council for Sustainable Development