CPAER Meteorology Exam Questions with Correct Answers

CPAER Meteorology Exam Questions with Correct Answers What is the primary driver of weather? - Answer-Uneven heating of the surface of the earth In a standard atmosphere the environmental lapse rate is - Answer-2º per 1,000ft The dry adiabatic lapse rate is - Answer-3º per 1,000ft The wet adiabatic lapse rate is - Answer-1.5º per 1,000ft A stable atmosphere occurs when the environmental lapse rate is - Answer-Shallow or negative An unstable atmosphere occurs when the environmental lapse rate is - Answer-Steeper than both the wet and dry adiabatic lapse rates A potentially unstable atmosphere occurs when the environmental lapse rate is - Answer-Somewhere between the dry an wet adiabatic lapse rates ISA - Answer-15º and pressure at sea level of 29.92" (1013.2hpa) The average height of the tropopause is - Answer-36,000ft For every 1,000ft climbed, mercury drops approximately - Answer-1" Relative humidity - Answer-The amount of water in the air relative to the maximum it can hold at given temperature and pressure Dewpoint - Answer-The temperature at which condensation begins Is humid air or dry air more dense? - Answer-Dry air Convection - Answer-Vertical movement of air Advection - Answer-Horizontal movement of air Deposition - Answer-When gas changes *directly* to a solid Isobars - Answer-Lines of constant/equal pressure Isotachs - Answer-Lines of constant/equal wind velocity Contour lines - Answer-Lines where the altitude at which a specified pressure occurs is constant Cloudy/rainy weather is associated with - Answer-Low pressure system (ascending air) Which way does air circulate in a low pressure system? - Answer-Counter-clockwise Warm/sunny weather is associated with - Answer-High pressure system (descending air) If you stand with your back to the wind in the northern hemisphere, the low will be on your - Answer-Left Below 3,000ft wind typically blows isobars - Answer-Across Squall (wind) - Answer-Rapid increase in wind speed lasting for a minute or longer Downburst - Answer-Strong localized downdraft from a thunderstorm Microburst - Answer-Downburst lasting less than 5 minutes with horizontal extent of 2nm or less Macroburst - Answer-Downburst lasting between 5-20 minutes with horizontal extent of 2nm or more Clouds are formed when - Answer-Air containing moisture is cooled to saturation resulting in the water condensing as liquid droplets or ice crystals High cloud - Answer-Base above 20,000ft (Cirrus, Cirrostratus, cirrocumulus) Middle cloud - Answer-Base between 6,500ft and 20,000ft (altostratus, altocumulus, altocumulus castellanos) Low cloud - Answer-Base below 6,500ft (Stratus, nimbostratus, fractostratus, cumulus) What are clouds of vertical development? - Answer-Cumulus clouds that grow vertically into towering cumulus or cumulonimbus Few clouds cover - Answer-0.1 to 2/8ths of the sky Scattered clouds cover - Answer-3/8ths to 4/8ths of the sky Broken clouds cover - Answer-5/8ths to 7/8ths of the sky Overcast clouds cover - Answer-8/8ths of the sky What is visibility in mist? - Answer-5/8 SM or greater What is visibility in fog? - Answer-Less than 5/8 SM What is ceiling described as? - Answer-The lowest layer of broken or overcast clouds At what rate will dewpoint drop as pressure decreases? - Answer-0.5º per 1,000ft Cloud base calculation - Answer-Difference between air temperature at the surface and dew point, divided by 3 Anabatic winds - Answer-Arise when a mountain or hillside is exposed to direct sunlight and is heated, causing warm air to rise (blows up mountain) Katabatic winds - Answer-Arise when heat is radiated off mountain or hill slopes *at NIGHT*, causing cooled air to sink down (blows down mountain) Mountain waves form - Answer-When wind blows over terrain leaving vorticies in its wake Downdrafts in mountain waves can reach vertical speeds of - Answer-5,000 FPM Radiation fog forms - Answer-On clear nights with a very gentle wind when the earth loses heat due to radiation cooling air temperature to the dewpoint Advection fog forms when - Answer-Air flows from a warm surface to a cool surface, may form with winds up to 15kts Frontal fog is associated with - Answer-A warm/cold front Frontal fog forms when - Answer-Rain falling from the warm air saturates the cold air Arctic sea smoke forms when - Answer-Cold air flows over relatively warm water Upslope fog forms when - Answer-Air forced to rise cools adiabatically, if upslope and moisture content is sufficient the dewpoint will be reached resulting in condensation