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Water Vapor

Global Map Water Vapor Image 1 Global Map Water Vapor Image 2 Global Map Water Vapor Image 3 Global Map Water Vapor Image 4 Global Map Water Vapor Image 5 Global Map Water Vapor Image 6 Global Map Water Vapor Image 7 Global Map Water Vapor Image 8 Global Map Water Vapor Image 9 Global Map Water Vapor Image 10 Global Map Water Vapor Image 11 Global Map Water Vapor Image 12 Global Map Water Vapor Image 13 Global Map Water Vapor Image 14 Global Map Water Vapor Image 15 Global Map Water Vapor Image 16 Global Map Water Vapor Image 17 Global Map Water Vapor Image 18 Global Map Water Vapor Image 19 Global Map Water Vapor Image 20 Global Map Water Vapor Image 21 Global Map Water Vapor Image 22 Global Map Water Vapor Image 23 Global Map Water Vapor Image 24 Global Map Water Vapor Image 25 Global Map Water Vapor Image 26 Global Map Water Vapor Image 27 Global Map Water Vapor Image 28 Global Map Water Vapor Image 29 Global Map Water Vapor Image 30 Global Map Water Vapor Image 31 Global Map Water Vapor Image 32 Global Map Water Vapor Image 33 Global Map Water Vapor Image 34 Global Map Water Vapor Image 35 Global Map Water Vapor Image 36 Global Map Water Vapor Image 37 Global Map Water Vapor Image 38 Global Map Water Vapor Image 39 Global Map Water Vapor Image 40 Global Map Water Vapor Image 41 Global Map Water Vapor Image 42 Global Map Water Vapor Image 43 Global Map Water Vapor Image 44 Global Map Water Vapor Image 45 Global Map Water Vapor Image 46 Global Map Water Vapor Image 47 Global Map Water Vapor Image 48 Global Map Water Vapor Image 49 Global Map Water Vapor Image 50 Global Map Water Vapor Image 51 Global Map Water Vapor Image 52 Global Map Water Vapor Image 53 Global Map Water Vapor Image 54 Global Map Water Vapor Image 55 Global Map Water Vapor Image 56 Global Map Water Vapor Image 57 Global Map Water Vapor Image 58 Global Map Water Vapor Image 59 Global Map Water Vapor Image 60 Global Map Water Vapor Image 61 Global Map Water Vapor Image 62 Global Map Water Vapor Image 63 Global Map Water Vapor Image 64 Global Map Water Vapor Image 65 Global Map Water Vapor Image 66 Global Map Water Vapor Image 67 Global Map Water Vapor Image 68 Global Map Water Vapor Image 69 Global Map Water Vapor Image 70 Global Map Water Vapor Image 71 Global Map Water Vapor Image 72 Global Map Water Vapor Image 73 Global Map Water Vapor Image 74 Global Map Water Vapor Image 75 Global Map Water Vapor Image 76 Global Map Water Vapor Image 77 Global Map Water Vapor Image 78 Global Map Water Vapor Image 79 Global Map Water Vapor Image 80 Global Map Water Vapor Image 81 Global Map Water Vapor Image 82 Global Map Water Vapor Image 83 Global Map Water Vapor Image 84 Global Map Water Vapor Image 85 Global Map Water Vapor Image 86 Global Map Water Vapor Image 87 Global Map Water Vapor Image 88 Global Map Water Vapor Image 89 Global Map Water Vapor Image 90 Global Map Water Vapor Image 91 Global Map Water Vapor Image 92 Global Map Water Vapor Image 93 Global Map Water Vapor Image 94 Global Map Water Vapor Image 95 Global Map Water Vapor Image 96 Global Map Water Vapor Image 97 Global Map Water Vapor Image 98 Global Map Water Vapor Image 99 Global Map Water Vapor Image 100 Global Map Water Vapor Image 101 Global Map Water Vapor Image 102 Global Map Water Vapor Image 103 Global Map Water Vapor Image 104 Global Map Water Vapor Image 105 Global Map Water Vapor Image 106 Global Map Water Vapor Image 107 Global Map Water Vapor Image 108 Global Map Water Vapor Image 109 Global Map Water Vapor Image 110 Global Map Water Vapor Image 111 Global Map Water Vapor Image 112 Global Map Water Vapor Image 113 Global Map Water Vapor Image 114 Global Map Water Vapor Image 115 Global Map Water Vapor Image 116 Global Map Water Vapor Image 117 Global Map Water Vapor Image 118 Global Map Water Vapor Image 119 Global Map Water Vapor Image 120 Global Map Water Vapor Image 121 Global Map Water Vapor Image 122 Global Map Water Vapor Image 123 Global Map Water Vapor Image 124 Global Map Water Vapor Image 125 Global Map Water Vapor Image 126 Global Map Water Vapor Image 127 Global Map Water Vapor Image 128 Global Map Water Vapor Image 129 Global Map Water Vapor Image 130 Global Map Water Vapor Image 131 Global Map Water Vapor Image 132 Global Map Water Vapor Image 133 Global Map Water Vapor Image 134 Global Map Water Vapor Image 135 Global Map Water Vapor Image 136 Global Map Water Vapor Image 137 Global Map Water Vapor Image 138 Global Map Water Vapor Image 139 Global Map Water Vapor Image 140 Global Map Water Vapor Image 141 Global Map Water Vapor Image 142 Global Map Water Vapor Image 143 Global Map Water Vapor Image 144 Global Map Water Vapor Image 145 Global Map Water Vapor Image 146 Global Map Water Vapor Image 147 Global Map Water Vapor Image 148 Global Map Water Vapor Image 149 Global Map Water Vapor Image 150 Global Map Water Vapor Image 151 Global Map Water Vapor Image 152 Global Map Water Vapor Image 153 Global Map Water Vapor Image 154 Global Map Water Vapor Image 155 Global Map Water Vapor Image 156 Global Map Water Vapor Image 157 Global Map Water Vapor Image 158 Global Map Water Vapor Image 159 Global Map Water Vapor Image 160 Global Map Water Vapor Image 161 Global Map Water Vapor Image 162 Global Map Water Vapor Image 163 Global Map Water Vapor Image 164 Global Map Water Vapor Image 165 Global Map Water Vapor Image 166 Global Map Water Vapor Image 167 Global Map Water Vapor Image 168 Global Map Water Vapor Image 169 Global Map Water Vapor Image 170 Global Map Water Vapor Image 171 Global Map Water Vapor Image 172 Global Map Water Vapor Image 173 Global Map Water Vapor Image 174 Global Map Water Vapor Image 175 Global Map Water Vapor Image 176 Global Map Water Vapor Image 177 Global Map Water Vapor Image 178 Global Map Water Vapor Image 179 Global Map Water Vapor Image 180 Global Map Water Vapor Image 181 Global Map Water Vapor Image 182 Global Map Water Vapor Image 183 Global Map Water Vapor Image 184 Global Map Water Vapor Image 185 Global Map Water Vapor Image 186 Global Map Water Vapor Image 187 Global Map Water Vapor Image 188 Global Map Water Vapor Image 189 Global Map Water Vapor Image 190 Global Map Water Vapor Image 191 Global Map Water Vapor Image 192 Global Map Water Vapor Image 193 Global Map Water Vapor Image 194
Water Vapor
Water Vapor Scale

Water is constantly cycling through the atmosphere. Water evaporates from the Earth's surface and rises on warm updrafts into the atmosphere. It condenses into clouds, is blown by the wind, and then falls back to the Earth as rain or snow. This cycle is one important way that heat and energy are transferred from the surface of the Earth to the atmosphere, and transported from one place to another on our planet.

Water vapor is also the most important greenhouse gas in the atmosphere. Heat radiated from Earth's surface is absorbed by water vapor molecules in the lower atmosphere. The water vapor molecules, in turn, radiate heat in all directions. Some of the heat returns to the Earth's surface. Thus, water vapor is a second source of warmth (in addition to sunlight) at the Earth's surface.

These maps show the average amount of water vapor in a column of atmosphere in a given month. The units are given in centimeters, which is the equivalent amount of water that could be produced if all the water vapor in the column were to condense. The lowest amounts of water vapor (0 centimeters) appear in white, and the highest amounts (6 centimeters) appear in dark blue. Areas of missing data appear in shades of gray. The maps are based on data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on NASA's Aqua satellite.

The most noticeable pattern in the time series is the influence of seasonal temperature changes and incoming sunlight on water vapor. In the tropics, a band of extremely humid air wobbles north and south of the equator as the seasons change. This band of humidity is part of the Intertropical Convergence Zone, where the easterly trade winds from each hemisphere converge and produce near-daily thunderstorms and clouds. Farther from the equator, water vapor concentrations are high in the hemisphere experiencing summer and low in the one experiencing winter.

Another pattern that shows up in the time series is that water vapor amounts over land areas decrease more in winter months than adjacent ocean areas do. This is largely because air temperatures over land drop more in the winter than temperatures over the ocean. Water vapor condenses more rapidly in colder air.

View, download, or analyze more of these data from NASA Earth Observations (NEO):
Water Vapor