METR 1014 1st EditionExam # 2 Study Guide Chapters:4 -6 The following questions/statements are meant to help you focus on the most important concepts thatwe’ve covered so far in class (and in the textbook). They do not represent all possible questions thatcould be asked on the exam.Exam 2 covers Week 5 – Week 8 Lectures (Chapters 4, 5 & 6 in the textbook)1. What are the top 3 reservoirs of water on the planet? Which is the largest reservoir of fresh water?- Three reservoirs of water are o Oceans- 96.5%o Ice caps and glaciers – 1.74%o Groundwater – 1.7%- The largest fresh water reservoir is polar ice caps 2. On average, how much water is in the atmosphere (in precipitable centimeters)?- 37.5 million billion tons of water - 332.6 million cubic miles of water 3. Describe the 4 main processes in the hydrologic (water) cycle discussed in class1. Evaporation- the process by which water changes from a liquid to a gas or vapora. Evaporation is the primary pathway that moves water from the liquid state at the surface into the atmosphere as water vaporb. Studies have shown that the oceans, seas, lakes, and rivers provide nearly 90 percent of the moisture in the atmosphere via evaporation, with the remaining 10 percent being contributed by plant transpirationc. Evaporation is a COOLING processd. Energy is required for evaporation to take place i. From any source; the sun, the atmosphere, the earth, or objects on the earth such as humans e. Sweating f. A major factor that influences the rate of evaporation is the relative humidity of the air around you2. Transpiration – is the evaporation of water from plants through stomata. Stomata are small openings found on the underside of leaves that are connected to vascular plant tissues. In most plants, transpiration is a passive process largely controlled by the humidity of the atmosphere and the moisture content of the soil. Of the transpired water passing through a These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.plant only 1% is used in the growth process of the plant. The remaining 99% is passed into the atmosphere a. How much water do plants transpire?i. During a growing season, a leaf will transpire many times more water than its own weight3. Condensation – is the process by which water vapor in the air is changed into liquid water. Inthe atmosphere, condensation may appear as clouds, fog, mist, dew or frost, depending upon the physical conditions of the atmosphere.a. Condensation is crucial to the water cycle because clouds may produce precipitation, which is the primary route for water to return to the Earth’s surface.b. Condensation is the opposite of evaporation. It RELEASES heat to the atmosphere4. Precipitation- is the result when the tiny condensation particles grow too large for the rising air to support, and thus fall to the eartha. Precipitation is water released from clouds in the form of rain, freezing rain, sleet, snow, or hailb. It is the primary connection in the water cycle that provides for the delivery of atmospheric water to the Earth c. Most precipitation falls as rain 5. What do we mean when we say “evaporation is a cooling process” (i.e. in sweating)?- For evaporation to take place, energy is required. The energy must me removed cooling the body. 6. How does an “evaporative cooler” work? In what humidity and temperature is it effective?- Pull in the dry, hot outdoor air and pass it through an evaporative pad that is kept wet by a supply of water. As a fan draws the air through the pad, the water in the pad evaporates,resulting in cooler air, which is pumped through the house. Much less energy is used as compared to an air conditioner.- Humidity is low and the temperatures are high7. Describe how the amount of water in the atmosphere can change as temperature changes- The higher the air temperature, the more water vapor will be present in the air at saturation8. What is meant by “vapor pressure”?- Portion of total atmospheric pressure due to water vapor (e.i. the partial pressure of water vapor) = e9. What is meant by “saturation vapor pressure”?- Function of temperature- As a measure of air’s total capacity for water vapor; the amount of water vapor that would be in the air at saturation10. What is meant by “relative humidity”?11. How is relative humidity calculated? (That is, know the equation for calculating relative humidity)- The ratio of the air’s actual water vapor content compared with the amount of water vapor required for saturation at that temperature and pressure.- Relative humidity depends on two factors: o The actual amount of moisture in the atmosphereo The temperature Remember that temperature determines how much water vapor can be in the air at saturation - Relative humidity is the ratio of the air’s water vapor content to its capacity- We can express/calculate Relative Humidity in a variety of ways:RH=WatervaporcontentWatervapor capacityRelativeHumidity=Vapor pressureSaturationvaporpressureX 100%12. Understand how relative humidity changes as 1) the amount of water in the atmosphere changes, and 2) the temperature changes1) Change the amount of water vapor available; if there is liquid water present, for instance, a lake, you can have an increase in relative humidity by evaporation from the surface of the lake. You’re adding water vapor, so the humidity increases.- Steam fog over a lake- An increase in the water vapor content of the air (with no change in temperature) increases the air’s relative humidity.- As more water vapor molecules are added to the air, there is a greater likelihood that some of the water vapor molecules will stick together and CONDENSE.- Condensation takes place in saturated air.2) The other way is to change the temperature of the air, while holding the water vapor constant. Even though there is no water source, and no water vapor is added, a lowering of air temperature results in a rise of relative humidity. - The amount of water vapor that could be present at saturation is less at the lower temperature, so the existing amount of water vapor represents a higher percentage of the saturation level of the air. o As the temp lowers, the water vapor molecules move more slowly, and more likely to stick togethero Condensation becomes more likely as the air approaches saturationo RH increases- Similarly, a rise in temperature