The Earth’s Atmosphere Contents Part 10 docx

Length 1 kilometer (km) = 1000 m = 3281 ft = 0.62 mi 1 mile (mi) = 5280 ft = 1609 mi = 1.61 km 1 meter (m) = 100 cm = 3.28 ft = 39.37 in. 1 foot (ft) = 12 in. = 30.48 cm = 0.305 m 1 centimeter (cm) = 0.39 in. = 0.01 m = 10 mm 1 inch (in.) = 2.54 cm = 0.08 ft 1 millimeter (mm) = 0.1 cm = 0.001 m = 0.039 in. 1 micrometer (µm) = 0.0001 cm = 0.000001 m 1 degree latitude = 111 km = 60 nautical mi = 69 statute mi Area 1 square centimeter (cm 2 ) = 0.15 in. 2 1 square inch (in. 2 ) = 6.45 cm 2 1 square meter (m 2 ) = 10.76 ft 2 1 square foot (ft 2 ) = 0.09 m 2 Volume 1 cubic centimeter (cm 3 ) = 0.06 in. 3 1 cubic inch (in. 3 ) = 16.39 cm 3 1 liter (l) = 1000 cm 3 = 0.264 gallon (gal) U.S. Speed 1 knot = 1 nautical mi/hr = 1.15 statute mi/hr = 0.51 m/sec = 1.85 km/hr 1 mile per hour (mi/hr) = 0.87 knots = 0.45 m/sec = 1.61 km/hr 1 kilometer per hour (km/hr) = 0.54 knots = 0.62 mi/hr = 0.28 m/sec 1 meter per second (m/sec) = 1.94 knots = 2.24 mi/hr = 3.60 km/hr Force 1 dyne = 1 gram centimeter per second per second = 2.2481 × 10 –6 pound (lb) 1 newton (N) = 1 kilogram meter per second per second =10 5 dynes = 0.2248 lb 421 APPENDIX A Units, Conversions, Abbreviations, and Equations Mass 1 gram (g) = 0.035 ounce = 0.002 lb 1 kilogram (kg) = 1000 g = 2.2 lb Energy 1 erg = 1 dyne per cm = 2.388 × 10 –8 cal 1 joule (J) = 1 newton meter = 0.239 cal =10 7 erg 1 calorie (cal) = 4.186 J = 4.186 × 10 7 erg Pressure 1 millibar (mb) = 1000 dynes/cm 2 = 0.75 millimeter of mercury (mm Hg) = 0.02953 inch of mercury (in. Hg) = 0.01450 pound per square inch (lb/in. 2 ) = 100 pascals (Pa) 1 standard atmosphere = 1013.25 mb = 760 mm Hg = 29.92 in. Hg = 14.7 lb/in. 2 1 inch of mercury = 33.865 mb 1 millimeter of mercury = 1.3332 mb 1 pascal = 0.01 mb =1 N/m 2 1 hectopascal (hPa) = 1 mb 1 kilopascal (kPa) = 10 mb Power 1 watt (W) = 1 J/sec = 14.3353 cal/min 1 cal/min = 0.06973 W 1 horse power (hp) = 746 W Powers of Ten Prefix nano one-billionth = 10 –9 = 0.000000001 micro one-millionth = 10 –6 = 0.000001 milli one-thousandth = 10 –3 = 0.001 centi one-hundredth = 10 –2 = 0.01 deci one-tenth = 10 –1 = 0.1 hecto one hundred = 10 2 = 100 kilo one thousand = 10 3 = 1000 mega one million = 10 6 = 1,000,000 giga one billion = 10 9 = 1,000,000,000 Temperature °C = 5 ⁄ 9 (°F –32) To convert degrees Fahrenheit (°F) to degrees Celsius (°C): Subtract 32 degrees from °F, then divide by 1.8. To convert degrees Celsius (°C) to degrees Fahrenheit (°F): Multiply °C by 1.8, then add 32 degrees. To convert degrees Celsius (°C) to Kelvins (K): Add 273 to Celsius temperature, as K = °C + 273. 422 Appendix A Appendix A 423 TABLE A.1 Temperature Conversions °F °C °F °C °F °C °F °C °F °C °F °C °F °C °F °C length meter m m mass kilogram kg kg time second sec sec temperature Kelvin K K density kilogram per kg/m 3 kg/m 3 cubic meter speed meter per m/sec m/sec second force newton m Խ kg/sec 2 N pressure pascal N/m 2 Pa energy joule N · m J power watt J/sec W *SI stands for Système International, which is the international sys- tem of units and symbols. TABLE A.2 SI Units* and Their Symbols Quantity Name Units Symbol –40 –40 –20 –28.9 0 –17.8 20 –6.7 40 4.4 60 15.6 80 26.7 100 37.8 –39 –39.4 –19 –28.3 1 –17.2 21 –6.1 41 5.0 61 16.1 81 27.2 101 38.3 –38 –38.9 –18 –27.8 2 –16.7 22 –5.6 42 5.6 62 16.8 82 27.8 102 38.9 –37 –38.3 –17 –27.2 3 –16.1 23 –5.0 43 6.1 63 17.2 83 28.3 103 39.4 –36 –37.8 –16 –26.7 4 –15.6 24 –4.4 44 6.7 64 17.8 84 28.9 104 40.0 –35 –37.2 –15 –26.1 5 –15.0 25 –3.9 45 7.2 65 18.3 85 29.4 105 40.6 –34 –36.7 –14 –25.6 6 –14.4 26 –3.3 46 7.8 66 18.9 86 30.0 106 41.1 –33 –36.1 –13 –25.0 7 –13.9 27 –2.8 47 8.3 67 19.4 87 30.6 107 41.7 –32 –35.6 –12 –24.4 8 –13.3 28 –2.2 48 8.9 68 20.0 88 31.1 108 42.2 –31 –35.0 –11 –23.9 9 –12.8 29 –1.7 49 9.4 69 20.6 89 31.7 109 42.8 –30 –34.4 –10 –23.3 10 –12.2 30 –1.1 50 10.0 70 21.1 90 32.2 110 43.3 –29 –33.9 –9 –22.8 11 –11.7 31 –0.6 51 10.6 71 21.7 91 32.8 111 43.9 –28 –33.3 –8 –22.2 12 –11.1 32 0.0 52 11.1 72 22.2 92 33.3 112 44.4 –27 –32.8 –7 –21.7 13 –10.6 33 0.6 53 11.7 73 22.8 93 33.9 113 45.0 –26 –32.2 –6 –21.1 14 –10.0 34 1.1 54 12.2 74 23.3 94 34.4 114 45.6 –25 –31.7 –5 –20.6 15 –9.4 35 1.7 55 12.8 75 23.9 95 35.0 115 46.1 –24 –31.1 –4 –20.0 16 –8.9 36 2.2 56 13.3 76 24.4 96 35.6 116 46.7 –23 –30.6 –3 –19.4 17 –8.3 37 2.8 57 13.9 77 25.0 97 36.1 117 47.2 –22 –30.0 –2 –18.9 18 –7.8 38 3.3 58 14.4 78 25.6 98 36.7 118 47.8 –21 –29.4 –1 –18.3 19 –7.2 39 3.9 59 15.0 79 26.1 99 37.2 119 48.3 Gas Law (Equation of State) The relationship among air pressure, air density, and air temperature can be expressed by Pressure = density × temperature × constant. This relationship, often called the gas law (or equation of state), can be expressed in symbolic form as: p = ρRT where p is air pressure, ρ is air density, R is a constant, and T is air temperature. Stefan-Boltzmann Law The Stefan-Boltzmann law is a law of radiation. It states that all objects with temperatures above absolute zero emit radiation at a rate proportional to the fourth power of their absolute temperature. It is expressed mathematically as: E = σ T 4 where E is the maximum rate of radiation emitted each second per unit surface area, T is the object’s surface temperature, and σ is a constant. APPENDIX B Equations and Constants 424 p = pressure in N/m 2 (SI) ρ = density (kg/m 3 ) T = temperature (K) R = 287 J/kg • K (SI) or R = 2.87 × 10 6 erg/g • K Units/Constants E = radiation emitted in W/m 2 (SI) σ = 5.67 × 10 –8 W/m 2 • K 4 (SI) or σ = 5.67 × 10 –5 erg/cm 2 • K 4 • sec T = temperature (K) Units/Constants Wien’s Law Wien’s law (or Wien’s displacement law) relates an object’s maximum emitted wavelength of radiation to the object’s temperature. It states that the wavelength of maximum emitted radiation by an object is inversely proportional to the object’s absolute temperature. In symbolic form, it is written as: w λ max = ____ T where λ max is the wavelength at which maximum radia- tion emission occurs, T is the object’s temperature, and w is a constant. Geostrophic Wind Equation The geostrophic wind equation gives an approximation of the wind speed above the level of friction, where the wind blows parallel to the isobars or contours. The equa- tion is expressed mathematically as: 1 ∆p V g = ____________ 2Ωsinφρ d where V g is the geostrophic wind, Ω is a constant (twice the earth’s angular spin), sinφ is a trigonometric func- tion that takes into account the variation of latitude (φ), ρ is the air density, ∆p is the pressure difference between two places on the map some horizontal distance (d) apart. Hydrostatic Equation The hydrostatic equation relates to how quickly the air pressure decreases in a column of air above the surface. The equation tells us that the rate at which the air pres- sure decreases with height is equal to the air density times the acceleration of gravity. In symbolic form, it is written as: ∆p ____ = –ρg ∆z where ∆p is the decrease in pressure along a small change in height ∆z, ρ is the air density, and g is the force of gravity. Appendix B 425 λ max = wavelength (micrometers) w = 0.2897 µm K T = temperature (K) Units/Constants V g = geostrophic wind (m/sec) Ω = 7.29 × 10 –5 radian*/sec φ = latitude ρ = air density (kg/m 3 ) d = distance (m) ∆p = pressure difference (newton/m 2 ) *2π radians equal 360°. Units/Constants ∆p = pressure difference (newton/m 2 ) ∆z = change in height (m) ρ = air density (kg/m 3 ) g = force of gravity (9.8m/sec 2 ) Units/Constants Relative Humidity The relative humidity of the air can be expressed as: e RH = __ × 100%. e s To determine e and e s , when the air temperature and dew-point temperature are known, consult Table B.1. Simply read the value adjacent to the air temperature and obtain e s ; read the value adjacent to the dew-point temperature and obtain e. 426 Appendix B e = actual vapor pressure (millibars) e s = saturation vapor pressure (millibars) RH = relative humidity (percent) Units/Constants –18 (0) 1.5 18 (65) 21.0 –15 (5) 1.9 21 (70) 25.0 –12 (10) 2.4 24 (75) 29.6 –9 (15) 3.0 27 (80) 35.0 –7 (20) 3.7 29 (85) 41.0 –4 (25) 4.6 32 (90) 48.1 –1 (30) 5.6 35 (95) 56.2 2 (35) 6.9 38 (100) 65.6 4 (40) 8.4 41 (105) 76.2 7 (45) 10.2 43 (110) 87.8 10 (50) 12.3 46 (115) 101.4 13 (55) 14.8 49 (120) 116.8 16 (60) 17.7 52 (125) 134.2 TABLE B.1 Saturation Vapor Pressure over Water for Various Air Temperatures Saturation Saturation Vapor Vapor Air Temperature Pressure Air Temperature Pressure (°C) (°F) (mb) (°C) (°F) (mb) Simplified Surface-Station Model Upper-Air Model (500 mb) 427 Cloud Coverage Common Weather Symbols APPENDIX C Weather Symbols and the Station Model Pressure Tendency Front Symbols 428 Appendix C Miles (statute) per hour Knots Calm Calm 1–2 3–8 9–14 15–20 21–25 26–31 32–37 38–43 44–49 50–54 55–60 61–66 67–71 72–77 78–83 84–89 119–123 1–2 3–7 8–12 13–17 18–22 23–27 28–32 33–37 38–42 43–47 48–52 53–57 58–62 63–67 68–72 73–77 103–107 1–3 4–13 14–19 20–32 33–40 41–50 51–60 61–69 70–79 80–87 88–96 97–106 107–114 115–124 125–134 135–143 144–198 Calm Kilometers per Hour Cold front (surface) Warm front (surface) Occluded front (surface) Stationary front (surface) Squall line Trough (trof) Ridge Dryline Wind Entries . 93 91 90 89 87 86 115 114 113 112 110 109 108 107 106 104 103 102 101 99 98 97 96 94 93 92 120 119 118 117 115 114 113 112 111 110 108 107 106 105 104 102 101 100 98 97 Air (Dry-Bulb) Temperature. 76 74 73 71 70 68 100 99 98 96 95 94 93 91 90 89 87 86 85 83 82 80 79 77 76 74 105 104 103 101 100 99 98 96 95 94 93 91 90 89 87 86 84 83 82 80 110 109 108 106 105 104 103 102 100 99 98 97 95 94. Table 434 125 120 117 111 107 103 99 95 91 87 83 78 73 69 64 128 122 116 111 107 102 97 93 88 84 79 74 69 64 131 123 116 111 105 100 95 90 85 80 75 70 65 131 123 115 108 102 97 91 86 81 76 71 65 141 130 120 112 105 99 93 87 82 77 72 66 139 127 117 109 101 94 88 83 77 72 66 148 135 123 113 104 96 90 84 78 73 67 143 130 118 107 98 91 85 79 73 67 151 137 123 110 101 93 86 79 74 68 143 129 115 104 95 87 80 74 68 150 135 120 107 96 88 81 75 69 142 126 110 98 89 81 75 69 149 132 114 100 90 82 76 70 138 119 102 91 83 76 70 144 124 106 93 85 77 70 130 109 95 86 77 70 136 113 97 86 78 71 117 99 87 78 71 122 102 88 79 71 105 89 79 71 108 91 80 72 140 135 130 125 120 115 110 105 100 95 90 85 80 75 70 0