Evaporation Removes The Equivalent Of 12 Meters Of Water

Evaporation Removes The Equivalent Of 12 Meter Of Water From The E

Evaporation causes the loss of approximately 1.2 meters of water annually from the global ocean. The total surface area of the ocean is approximately 361,132,000 square kilometers, and the density of seawater is roughly 1000 kg per cubic meter. The energy necessary to evaporate 1 kg of water is about 2.3 × 106 joules. This paper calculates the total mass of water evaporated annually, the energy required per unit area, and compares this to the average solar energy absorbed at Earth's surface.

Paper For Above instruction

To determine the total mass of water evaporated annually from the ocean, we start with the given data: a water column of 1.2 meters over the entire ocean surface. The volume of water evaporated per year can be calculated by multiplying the surface area by this height:

Total volume of water evaporated per year = Surface area × Evaporated height

Converting the ocean surface area to square meters:

Surface area = 361,132,000 km2 = 361,132,000 × 106 m2 = 3.61132 × 1014 m2

Evaporated volume = 3.61132 × 1014 m2 × 1.2 m = 4.333584 × 1014 m3

Since 1 m3 of seawater has a mass of 1000 kg, the total mass of water evaporated annually is:

Mass = Volume × Density = 4.333584 × 1014 m3 × 1000 kg/m3 = 4.333584 × 1017 kg

Next, the energy required to evaporate this amount of water is calculated by multiplying the total mass by the energy per kilogram:

Energy = 4.333584 × 1017 kg × 2.3 × 106 J/kg = 9.9562192 × 1023 J

To find the energy absorption per square meter of ocean surface, divide the total energy by the total surface area:

Energy per m2 = 9.9562192 × 1023 J / 3.61132 × 1014 m2 ≈ 2.756 × 109 J/m2

Therefore, approximately 2.76 × 109 joules of energy must be absorbed per square meter of ocean surface annually to sustain this level of evaporation.

Comparing this to the average solar energy absorbed by the Earth's surface, which is about 170 to 200 W/m2 (or approximately 1.5 × 103 J/m2/second) averaged over the year, we find that the energy required for evaporation is significantly higher on an annual basis, reflecting the enormous energy flux involved in phase changes of water.

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