Hydrologic Cycle www assignmentpoint com The hydrologic cycle

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Hydrologic Cycle www. assignmentpoint. com

Hydrologic Cycle www. assignmentpoint. com

 • The hydrologic cycle begins with the evaporation ofwater from the surface of

• The hydrologic cycle begins with the evaporation ofwater from the surface of the ocean. As moist air is lifted, it cools and water vapor condenses to form clouds. Moisture is transported around the globe until it returns to the surface as precipitation. www. assignmentpoint. com

– Hydrological Cycle – 4 main parts • Evaporation of water from the oceans

– Hydrological Cycle – 4 main parts • Evaporation of water from the oceans • Transport of water vapor in the atmosphere • Condensation and precipitation • Return of water to ocean by rivers and streams www. assignmentpoint. com

 • The main events of the hydrologic cycle are: (1) The evaporation of

• The main events of the hydrologic cycle are: (1) The evaporation of water from the ocean, (2) the transport of water vapor through the atmosphere, (3) condensation and precipitation of water on the land, and (4) return of water to the ocean by rivers and streams. www. assignmentpoint. com

 • Cloud-forming Processes – Upward Air Movement • Convection resulting from differences in

• Cloud-forming Processes – Upward Air Movement • Convection resulting from differences in temperature • Barriers such as mountain ranges which provide lift to air masses • Meeting of moving air masses with different densities. www. assignmentpoint. com

– Adiabatic Cooling • Decrease in temperature of an expanding gas – Adiabatic Heating

– Adiabatic Cooling • Decrease in temperature of an expanding gas – Adiabatic Heating • Heating of a gas as it undergoes compression – Dry Adiabatic Lapse Rate • Rate of cooling in the absence of condensation • About 10 OC for each increase or decrease of 1 km (5. 5 OF/1, 000 ft) www. assignmentpoint. com

 • As a parcel of dry air is moved upward, it expands and

• As a parcel of dry air is moved upward, it expands and cools according to the dry adiabatic lapse rate. This graph compares the temperature of a rising and adiabatically cooling parcel of dry air with the average temperatures of the surrounding atmosphere when the temperature at the surface is 30 OC (86 O F). www. assignmentpoint. com

– Atmospheric Stability • Stability – When the atmospheric lapse rate is less that

– Atmospheric Stability • Stability – When the atmospheric lapse rate is less that the dry adiabatic lapse rate • Instability – When the atmospheric lapse rate is greater than the dry adiabatic lapse rate. www. assignmentpoint. com

 • If a parcel of air is moved up or down, it will

• If a parcel of air is moved up or down, it will cool or warm according to the dry adiabatic lapse rate. In a state of atmospheric stability, the parcel of air will always be cooler, and therefore more dense, than the surrounding air at any altitude. It will, therefore, return to the original level when www. assignmentpoint. com the upward force is removed.

 • In a state of atmospheric instability, a parcel of air will always

• In a state of atmospheric instability, a parcel of air will always be warmer, and therefore less dense, than the surrounding air at any altitude. The parcel will, therefore, continue on in the direction pushed www. assignmentpoint. com when the upward force is removed.

– Wet Adiabatic Lapse Rate • The lapse rate for a parcel of air

– Wet Adiabatic Lapse Rate • The lapse rate for a parcel of air at a slow rate and releasing the temperature equal to its latent heat of vaporization – Supersaturated • When the air contains more water vapor than is the normal amount of water vapor www. assignmentpoint. com

 • When the dew point temperature is reached in a rising parcel of

• When the dew point temperature is reached in a rising parcel of air, the latent heat of vaporization is released as water vapor condenses. This release of heat warms the air, decreasing the density and accelerating the ascent. The new lapse rate from the release of latent heat is called the wet www. assignmentpoint. com adiabatic lapse rate.

 • Origin of Precipitation – Processes of precipitation formation • Coalescence – When

• Origin of Precipitation – Processes of precipitation formation • Coalescence – When water droplets merge with millions of other water droplets. • Growth of ice crystals – Ice crystals can capture other water molecules and grow to enormous sizes. www. assignmentpoint. com

– Supercooled • If water remains in the liquid state after the temperature is

– Supercooled • If water remains in the liquid state after the temperature is below the freezing point. – Ice-forming nuclei • Solid particles on which the ice forms www. assignmentpoint. com

 • Precipitation is water in the liquid or solid form that returns to

• Precipitation is water in the liquid or solid form that returns to the surface of the earth. The precipitation you see here is liquid, and each raindrop is made from billions of the tiny droplets that make up the clouds. The tiny droplets of clouds become precipitation by merging to form larger droplets or www. assignmentpoint. com by the growth of ice crystals that melt while falling.