© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Caption goes here © Jonesand can & several Bartlett lines Learning, LLC © Jones & Bartlett Learning, LLC NOTlong FOR as shownSALE here. OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Caption goes here and can several lines long as shown here. Caption goes here and can several lines long as shown here. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC 4NOT FOR SALEWater OR DISTRIBUTION in the AtmosphereNOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION CHHAPTTEER OUUTLLININE INTRODUCTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOTEVAPORATION: FOR SALE OR THE DISTRIBUTION SOURCE OF ATMOSPHERICNOT WATER FOR SALE OR DISTRIBUTION MEASURING WATER VAPOR IN THE AIR ■ Mixing Ratio ■ Vapor Pressure © Jones & Bartlett■ Relative Learning, Humidity LLC © Jones & Bartlett Learning, LLC NOT FOR SALE■ ORDew DISTRIBUTION Point/Frost Point NOT FOR SALE OR DISTRIBUTION CONDENSATION AND DEPOSITION: CLOUD FORMATION ■ Solute and Curvature Effects © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 96 © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. Water in the Atmosphere 97 © Jones & Bartlett Learning, LLC © Jones & CBartlettHAPTTEE Learning,R OUUTLIN LLCE, CONTINUED NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION NUCLEATION ■ Condensation Nuclei ■ Ice Nuclei © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ■ Cloud ParticleNOT Growth FOR bySALE Condensation OR DISTRIBUTION and Deposition NOT FOR SALE OR DISTRIBUTION FOG FORMATION ■ Radiation Fog ■ Advection Fog ■ ©Evaporation Jones & Bartlett Fog Learning, LLC © Jones & Bartlett Learning, LLC ■ NOTUpslope FOR Fog SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION LIFTING MECHANISMS THAT FORM CLOUDS STATIC STABILITY AND CLOUD DEVELOPMENT © Jones & Bartlett■ The Saturated Learning, Adiabatic LLC Lapse Rate © Jones & Bartlett Learning, LLC NOT FOR SALE■ Conditionally OR DISTRIBUTION Unstable Environments NOT FOR SALE OR DISTRIBUTION CLOUD CLASSIFICATION ■ Low Clouds ■ Precipitating Clouds ■ Middle Clouds© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ■ High Clouds NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION CLOUDS AND THE GREENHOUSE EFFECT CLOUD COMPOSITION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC PRECIPITATION NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION ■ Precipitation Growth in Warm Clouds ■ Precipitation Growth in Cold Clouds ■ Precipitation Types ■ Clouds, Lapse Rates, and Precipitation Near Mountains © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALEPUTTING OR DISTRIBUTION IT ALL TOGETHER NOT FOR SALE OR DISTRIBUTION ■ Summary ■ Key Terms ■ Review Questions ■ Observation ©Activities Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION AFTER COMPLETING THIS CHAPTER, YOU SHOULD BE ABLE TO: • Define saturation and its importance in the atmosphere • Explain why there can be more water vapor in warm air than cold air and ©how Jones this affects& Bartlett the atmosphereLearning, LLC © Jones & Bartlett Learning, LLC • NOTDescribe FOR how SALE clouds OR and DISTRIBUTION precipitation form NOT FOR SALE OR DISTRIBUTION • Identify the major cloud and precipitation types, and explain the significant differences among them © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. 98 CHAPTER 4 Water in the Atmosphere © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning,INTRODUCTION LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION On January 26–28, 2009, a layer of ice encased the central United States from Texas to West Virginia. The precipitation fell mostly as rain, but the temperatures at the ground were cold enough for the rain to freeze on contact with anything it touched (see fi gures below). The storm coated© Jones many & areas Bartlett with Learning,more than an LLC inch (2.5 cm) of ice, killing© Jones more than & Bartlett 60 people— Learning, LLC 35NOT in Kentucky FOR SALE alone. OR Most DISTRIBUTION of the deaths were due to traffi c accidents,NOT FOR extreme SALE cold, OR and DISTRIBUTION carbon monoxide poisoning (caused by power generators or kerosene heaters being used indoors without proper ventilation). Trees fell and power lines snapped under the weight of the ice, leaving more than 1.3 million people without electricity. It seemed as if Mother Nature had declared an icy war on the region—and as if to confi rm this impression, the entire Kentucky Army © Jones & BartlettNational GuardLearning, was mobilized LLC to help with the many© problems Jones left& Bartlett in the wake Learning, of this storm. LLC NOT FOR SALEIn OR this DISTRIBUTION chapter, we explore water in the atmosphereNOT FOR in all SALE its phases: OR water DISTRIBUTION vapor, liquid water, and ice. We will explain how fog, clouds, and precipitation form. We will also learn how slightly different temperature conditions can turn a cold rain into pellets of ice or into a destructive freezing rain that can paralyze half a nation. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 3.00 2.50 © Jones & Bartlett Learning, LLC © Jones & Bartlett2.00 Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR1.75 DISTRIBUTION 1.50 1.25 1.00 0.75 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC0.50 NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION0.25 0.10 0.01 0.00 © Jones & Bartlett Learning, LLC © Jones &Inches Bartlett of Freezing Learning, Rain LLC NOT FOR SALE OR DISTRIBUTION NOT FORin theSALE January OR 2009 DISTRIBUTION Ice Storm Source: NOAA/NWS. © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. Evaporation: The Source of Atmospheric Water 99 © Jones & Bartlett Learning, LLC © Jones & EVAPORATION:Bartlett Learning, THE LLC SOURCE OF ATMOSPHERIC WATER NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Water is, near the surface, the atmosphere’s most abundant trace gas. How does water enter the atmosphere? Evaporation puts it there. As we learned in Chapter 1, evaporation is the process by which water is converted from liquid form into its gaseous state, water vapor. Evaporation occurs constantly over the surface© Jones of the & Earth. Bartlett When Learning, water molecules LLC at the surface of liquid© waterJones & Bartlett Learning, LLC gain enough energy toNOT escape FOR as vapor SALE into OR the DISTRIBUTIONair above, evaporation results. As we learnedNOT in FOR SALE OR DISTRIBUTION Chapter 2, it takes a lot of latent heat energy to change liquid water to vapor. Evaporation therefore occurs more rapidly over warmer surfaces, which supply water molecules with enough energy to escape into the atmosphere. Evaporation is also greater when the atmospheric pressure is low, the wind speed is high, and there is relatively little water vapor already in the air. To© understandJones & evaporationBartlett Learning, better, let’s consider LLC the following example.© Put Jones some liquid & Bartlett water in Learning, LLC a closedNOT container. FOR KeepSALE the OR container DISTRIBUTION at a constant temperature and pressure.NOT Initially FOR the SALE container OR DISTRIBUTION has only liquid water in it (FIGURE 4-1a). Some individual molecules in the liquid water will have more (and some will have less) kinetic energy than the average. For instance, a water molecule in the liquid phase might gain kinetic energy considerably above the average because of several rapid © Jones &collisions Bartlett with Learning, neighboring LLC molecules. Now imagine such© Jones a molecule & Bartlett at the liquid’s Learning, surface, theLLC NOT FORboundary SALE ORbetween DISTRIBUTION the water and the air. If it has enoughNOT kinetic FOR energy SALE to overcome OR DISTRIBUTION the attractive force of nearby molecules and is moving toward the air, it may escape from the liquid (Figure 4-1b). H H O = H O molecule 2 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION (a) (b) Air 20° C © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Water © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALEDry OR air DISTRIBUTIONis above water. EvaporationNOT FOR of water