ATSC-110, Chp. 1-3
What atmospheric layer contains a vast majority of our weather?
The troposphere: A severe thunderstorm with overshooting tops can extend into the lower levels of the stratosphere but by far a majority of the weather is confined to the troposphere.
Explain the concept of air pressure in terms of mass of air above a level. In other words, how do air pressure values change with height?
The weight of the air molecules acts as a force upon the earth. The amount of force exerted over an area of surface is called "air pressure". The pressure at any level in the atmosphere may be measured in terms of the total mass of air above any point. So with an increase in height, pressure values will decrease.
What is the difference between Universal, Greenwich and Zulu Time?
There is no difference. All three refer to the same Time Coordinate System. In Meteorology we use one time zone for the whole world that is based on the time along the Prime Meridian (0˚ longitude) which runs through Greenwich, England. The names given to this time coordinate system vary as stated above. In Grand Forks (central time zone) there is a -6 hour difference during standard time (winter) and a -5 hour difference during daylight saving time (summer) between Universal time and our Local time .
1. In what atmospheric layer do we find the lowest average air temperature? 2. The highest average temperature? 3. The highest concentration of ozone?
1.Mesosphere, average value of -130˚F 2. Thermosphere "hot layer", but due to the air density being so low, air temperatures are not measured directly. 3. Stratosphere, 97% of atmospheric ozone is found in the stratosphere
Identify and name the major lines of latitude starting north and working south.
90˚ N North Pole 66½˚ N Arctic Circle 23½˚ N Tropic of Cancer 0˚ Equator 23½˚ S Tropic of Capricorn 66½˚ S Antarctic Circle 90˚ S South Pole
Convection is the transfer of heat by the upward and downward motion of a fluid or gas. Therefore air in the troposphere is rising and descending. How does the temperature of a parcel of air change when it is rising and falling?
A rising parcel of air will expand as it moves into an environment of lower atmospheric pressure values and therefore cool. A sinking or subsiding air parcel will compress while moving into an environment of higher atmospheric pressure values and therefore warm. Therefore rising air will cool due to expansion and sinking air will warm due to compression.
What is a 'sensible temperature'?
A wind-chill temperature and heat-index temperature are both considered sensible temperatures. These are temperatures that the body feels like in contrast to the actual temperature of the environment as measured with a thermometer. In extreme cases, very low wind-chill and high heat-index temperatures can be life threatening.
Why has "Carbon Dioxide (CO2)" been on the increase over the past 100 years?
CO2 (0.041% of air by volume) enters the atmosphere mainly form the decay of vegetation, but it also comes from volcanic eruptions, the exhalations of animal life, the burning of fossil fuels, and from deforestation. CO2 is removed from the atmosphere by plants consuming CO2 to produce green matter (photosynthesis). The increase in CO2 appears to be due mainly to the burning of fossil fuels (80%) and deforestation of the rain forest (20%) over the past 100 years.
During the Northern Hemisphere's summer, the daylight hours in the far northern latitudes are longer than those in the mid-latitudes, but the temperatures are not the warmest farther north. Why?
Even though the far northern latitudes are receiving more hours of sunlight in the summer, the sun angle is still considerably low. It is true that the northern latitudes are receiving more solar radiation at the top of the atmosphere, but the sunlight penetrating through the northern atmosphere will be partially scattered by fine dust and air molecules, reflected by clouds, and absorbed by atmospheric gases. These factors combined, reduce the amount of solar radiation reaching the ground. The solar radiation that does reach the ground is partially reflected by ice and snow and is used to melt ice. Therefore, there is a limited amount of solar radiation left over to do the actual heating of the surface and lower atmosphere.
Define 'Latent Heat'. Define 'Sensible Heat'.
Latent Heat is the heat energy required to change a substance, such as water, from one state, or phase, to another. Sensible Heat (actual temperature) is the heat we can feel and measure with a thermometer. Note: Sensible Temperature is the sensation of temperature that the human body feels in contrast to the actual temperature of the environment. Wind-chill and Heat Index are Sensible Temperatures, what the air temperature 'feels like'.
Identify and provide the average elevations of the standard atmospheric pressure levels?
Level (mb) Height (ft) Height (mi) 1000 Near sea-level 925 2,500 0.5 850 5,000 1.0 700 10,000 2.0 500 18,000 3.5 300 30,000 5.5 200 40,000 7.5 These numbers are important, especially relating the various mb levels to feet above sea-level.
Which wavelength carries the most energy - infrared, visible, or ultraviolet?
Longer waves carry less energy than shorter waves, therefore, we must determine which one has the shortest wavelength. Infrared - greater than .70 μm Visible - between .40 and .70 μm Ultraviolet - less than .40 μm Therefore, ultraviolet wavelengths carry the most energy out of the three types of radiation mentioned here.
Explain why the warmest daily temperatures typically occur during the mid to late afternoon even though the sun's rays are most direct at solar noon.
Solar noon depicts the time when incoming solar radiation is the greatest. But there continues to be a surplus of incoming solar radiation versus outgoing infrared radiation until mid to late afternoon. Therefore, maximum daily temperatures typically occur 2-4 hours later than the time when the surface is receiving the greatest amount of incoming solar radiation.
Distinguish between temperature and heat.
Temperature is a measure of molecular motion Heat is energy in the process of being transferred from one object to another because of the temperature difference between the two objects.
How does the average speed of air molecules relate to the air temperature?
Temperature is a measure of the average speed of the atoms and molecules (molecular motion), where higher temperatures correspond to faster average speeds of atoms and molecules and colder temperatures correspond to slower average speeds of atoms and molecules. The temperature of 'Absolute Zero' on the Kelvin temperature scale would correlate to NO molecular motion.
Explain how the earth's atmospheric 'Greenhouse Effect' works?
The 'Greenhouse Effect' works because atmospheric gases such as water vapor and carbon dioxide are good absorbers of infrared (longwave) radiation but poor absorbers of visible (shortwave) radiation. This allows visible (shortwave) radiation to reach the earth's surface. The earth's surface will then re-radiate this energy as infrared (longwave) radiation. The re-radiated infrared (longwave) radiation can now be absorbed by the various greenhouse gases (water vapor and carbon dioxide) which results in an increase in the earth's temperature.
What are the main factors that determine seasonal temperature variations?
The 23.5˚ tilt in the earth's axis combined with the earth's elliptical orbit around the sun are the main factors that determine seasonal temperature variations. The angle at which the sun's rays strike the earth and the length of daylight hours are directly related to the tilt of the earth's axis and the position where the earth is located in its orbit around the sun.
Explain how the atmosphere "protects" inhabitants on the earth's surface.
The atmosphere contains a gas called "ozone". This key element, small in concentration (0.000004% by volume), is more concentrated in the upper atmosphere (Stratosphere). Ozone shields plants, animals, and humans from the sun's harmful incoming ultraviolet radiation.
1. During standard time (winter), 12 UTC would be ______ in Grand Forks. 2. During daylight saving time (summer), 12 UTC would be ______ in Grand Forks. 3. During standard time (winter), 18 UTC would be ______ in Grand Forks. 4. During daylight saving time (summer), 21 UTC would be ______ in Grand Forks.
1)6:00 AM CST 2)7:00 AM CDT 3)12:00 PM CST(Noon) 4)4:00 PM CDT
Explain why the daily range of temperature is normally greater 1.) in dry regions versus humid regions and 2.) on clear days versus cloudy days.
1)Dry regions have clearer skies and less water vapor in the atmosphere versus a humid region. Therefore, incoming solar radiation is greater during the day in a dry region because the sun's energy is not reflected by clouds causing higher daytime temperatures. Radiational cooling is greater during the overnight hours in a dry region because less water vapor in the atmosphere is not available to re-radiate the outgoing infrared radiation back to the surface. This will cause lower overnight temperatures. 2)Clear days maximize daytime incoming solar radiation and nighttime radiational cooling (maximum daily temp range) while cloud cover will decrease daytime incoming solar radiation and hamper radiational cooling (minimal daily temp range).
Based on the temperature profile, list the layers of the atmosphere from the lowest to the highest in elevation.
1)Troposphere (sfc to 11km) temperatures decrease with height 2)Stratosphere (11 to 50km) temperatures increase with height 3)Mesosphere (50 to 85km) temperatures decrease with height 4)Thermosphere (85 to 500km) temperatures increase with height
Define these terms that describe the Daily, Monthly, and Yearly temperature values. 1. Daily or Diurnal Range of Temperature 2. Mean or Average Daily Temperature 3. Mean or Average Monthly Temperature 4. Annual Range of Temperature 5. Mean or Average Annual Temperature
1. Daily or Diurnal Range of Temperature The difference between the daily maximum and minimum temperature. 2. Mean or Average Daily Temperature The average of the highest and lowest temperature for a 24-hour period. 3. Mean or Average Monthly Temperature The average of the mean daily temperatures for a month (GFK: Jan 6.7°F, July 68.6°F) 4. Annual Range of Temperature The difference between the average monthly temperature of the warmest and coldest months GFK: 68.6 - 6.7 = 61.9°F 5. Mean or Average Annual Temperature The average temperature for the entire year which represents the average of the twelve average monthly temperatures. GFK = 40.0°F
How would you construct an instrument shelter that holds thermometers to measure atmospheric temperature?
1. Paint it white 2. Face the door to the north 3. Put slots in the side for free air flow 4. Place it 5.0 to 5.5 feet above the ground 5. In this region, make sure it is located above a grassy surface and away from buildings with their concrete and paved lots.
How many total calories are required to raise the temperature of a 40 gram block of ice from -20°C to 0°C, melt the 40 gram block of ice, and then raise the temperature of the melt water from 0°C to 10°C? Note: You will need to use two 'specific heat values' and one 'latent heat value' to solve this problem.
1. Raise temp of ice 20°C. (Specific Heat value of Ice) 40gr X 20°C X 0.5cal/gr°C = 400 cal 2. Melt the 40 gram block of ice. (Latent Heat value to Melt) 40gr X 80cal/gr = 3,200 cal 3. Raise temp of water 10°C. (Specific Heat value of Water) 40 gr X 10°C X 1.0cal/gr°C = 400 cal 4. Total calories used in process. 400 + 3,200 + 400 = 4,000 calories
What are some of the important roles that water plays in our atmosphere?
1.It is the only substance that exists as a gas, a liquid, and solid at temperatures and pressures normally found near the earth's surface. 2.It releases large amounts of heat called "latent heat" when water vapor changes to a liquid or ice. This heat release is an important source of energy for storm development. 3.It is a potent greenhouse gas because it strongly absorbs a portion of the earth's outgoing radiant energy. Thus, water vapor plays a significant role in the earth's heat-energy balance. (Greenhouse Effect)
How do the wavelengths of maximum radiation emitted by the sun differ from the wavelengths of maximum radiation emitted by the surface of the earth?
According to Wien's law, (λmax = constant / T ) When using the temperature of the sun's surface (6000 K) the maximum wavelength at which radiation is emitted from the sun occurs at .48 μm. (Visible Light category) When using the temperature of the earth's surface (288 K) the maximum wavelength at which radiation is emitted from the earth occurs at 10.06 μm. (Infrared category) .48 μm fits into the visible light or shortwave category 10.06 μm fits into the infrared or longwave category
How does the temperature of an object influence the radiation that it emits?
According to the Stefan-Boltzmann law (E = σT4); as the temperature of an object increases, more total radiation is emitted each second. Consequently, a small increase in temperature results in a large increase in the amount of radiation emitted because doubling the temperature of an object increases the maximum energy output by a factor of 16 (24).
What are aerosols, and list some of the aerosols in our atmosphere?
Aerosols are impurities found in the atmosphere that are from both natural and human sources. Some of these aerosols are: 1.Dust and soil particles 2.Microscopic salt particles 3.Smoke 4.Volcanic ash
At the same pressure, why is cold air more dense than warm air?
Air temperature is a measure of the average speed of the molecules. In the cold volume of air, the molecules move more slowly and crowd closer together. In the warm volume, molecules move faster and are farther apart. Since the molecules are closer together in the cold volume, the density is greater for colder air.
Define 'albedo'. What are the albedo values for these surfaces? You will need to look up these values in the book or online. 1.Snow 2.Clouds 3.The earth and atmosphere 4.Dry dark land 5.Water 6.Forest
Albedo → The percent of radiation returning from a surface compared to the amount of radiation initially striking that surface. 1.Snow (Fresh) 75 - 90% 2.Clouds (Thick) 60 - 90% 3.The earth and atmosphere 30% 4.Dry dark land 5 - 20% 5.Water 10% 6.Forest 3-10%
What is Kinetic energy?
Any body in motion has kinetic energy, therefore kinetic energy is the energy within a body that is a result of its motion. (KE = ½ mv2) where: m is the object's mass and v is the object's velocity. Examples: Heat Energy → molecular motion Radiant energy → that received from the sun
Why do air pressure and density always decrease with increasing height above the surface? Why do air pressure and density decrease more rapidly near the earth's surface than aloft?
As we climb in elevation, fewer air molecules are above us; hence, air pressure and density decrease with increasing height. The air pressure and density decrease rapidly at first because air is compressed near the surface due to the earth's gravitational force.
What is the difference between latitude and longitude?
Both are used to measure earth coordinates. Latitude (Parallels) are lines that run east-west and measure distance north-south. Lines of latitude are parallel to one another with 1˚ of latitude equaling 60 nautical miles. Longitude (Meridians) are lines that run north-south and measure distance east-west. Lines of longitude are not parallel and converge towards the poles therefore there is no equal distance between degrees of longitude.
The overnight skies are clear and the wind is calm in Grand Forks. The overnight skies are cloudy and the wind is calm in Fargo. Which city should experience the coldest morning low temperature?
Both cities have calm winds but Grand Forks is clear and Fargo is cloudy. The cloud cover over Fargo is able to capture some of the emitted infrared radiation from the surface while most of the emitted infrared radiation in Grand Forks will escape into outer space since the skies are clear. Therefore Fargo has an enhanced 'Greenhouse Effect' with the cloud cover and will cause the overnight temperatures to remain warmer than those in Grand Forks.
What nighttime weather conditions would create the greatest temperature difference from the surface to an area just a few feet above the surface?
Clear skies with calm surface winds: As night progresses, the ground and the air in contact with the ground continue to cool more rapidly than the air a few feet higher up. This is due to the ground and the air just above the ground radiating infrared energy, a process called radiational cooling. Radiational cooling is most efficient under clear skies and calm winds. An increase in cloud cover and/or windy conditions will decrease the effects of radiational cooling.
What daytime weather conditions, during the summer, would create the greatest temperature difference from the surface to an area just a few feet above the surface?
Clear skies with calm surface winds: The sun heats the ground which in turn heats the air in contact with the ground by conduction. Because air is such a poor conductor of heat, there exists a thermal boundary separating the hot surface air from the cooler air above. On windy days, turbulent eddies are able to mix hot surface air with the cooler air above which will decrease the temperature difference between the surface air and the air above the surface.
Name the phase change processes for water and the amount of energy need to do each process.
Condensation +600cal/gr Evaporation - 600cal/gr Freezing +80cal/gr Melting - 80cal/gr Deposition (vapor → ice) +680cal/gr Sublimation (ice → vapor) - 680cal/gr + heat energy added to the environment - heat energy taken from the environment
Name and define the three 'Heat Transfer' mechanisms
Conduction → The transfer of heat form 'molecule to molecule' within a substance, hot to cold. Convection → The transfer of heat by the 'mass movement of a fluid' (water & air) - convection is vertical movement - advection is horizontal movement Radiation → The transfer of heat by the 'propagation of electromagnet waves' through a vacuum. Energy received from the sun and all things whose temperature is above absolute zero.
What process contributes to the earth's albedo being 30%?
Contributing factors to the earth's albedo being 30% are: 4% is reflected or scattered by the earth's surface, 6% by gases within the atmosphere, and 20% by clouds.
What weather conditions are best suited for the formation of a cold night and a strong radiation inversion in Grand Forks?
Grand Forks will experience its coldest early morning temperatures when the conditions are favorable for the development of a strong radiational inversion. During the winter months, this will occur when the skies are clear, the winds are calm, the air is dry, and there is snow on the ground.
What is the standard atmospheric pressure at sea level in: Inches of Mercury ("Hg) Millibars (mb)
Inches of mercury 29.92" Hg Millibars 1013.25 mb
The earth is closet to the sun in January when the Southern Hemisphere is experiencing summer. So why is the Southern Hemisphere summer not as warm as the Northern Hemisphere summer?
It is true that the sun is closet to the earth during the period when the southern hemisphere is experience summer (January 4th) but the larger amount of water in the southern hemisphere (81%) versus the northern hemisphere (61%) causes summer temperatures to be cooler in the southern hemisphere. But the southern hemisphere will have warmer winter temperatures versus the northern hemisphere with the exception of the Antarctic region which is the coldest spot on the earth.
Name and describe the three different temperature scales.
Kelvin scale → starting point is absolute zero (0K), freezing point (273K) and boiling point (373K) at sea level. The Kelvin scale contains no negative numbers and is therefore quite convenient for scientific calculations. Celsius scale → The number 0 (zero) is assigned to the temperature at which pure water freezes and 100 to the temperature at which pure water boils at sea level. (100 divisions between freezing and boiling) Fahrenheit scale → The number 32 is assigned to the temperature at which pure water freezes and 212 to the temperature at which pure water boils at sea level. (180 divisions between freezing and boiling)
Why does Grand Forks, ND have much colder temperatures than Seattle, WA in January even though both locations are roughly the same latitude (48˚ N)?
Mid-ocean surface temperatures change relatively little from summer to winter compared to the much larger annual temperature changes over the middle of continents. This is due to the difference in specific heat values between water (1.0 cal/g˚C) and land (0.3 cal/g˚C). Water will heat and cool slower than land due to its larger heat capacity. Therefore, the water will moderate the air temperatures in Seattle since it is located near the coast, versus Grand Forks which is located in the middle of the North American continent.
List the two most abundant permanent gases in today's atmosphere.
Nitrogen 78.08% Oxygen 20.95%
What is potential energy?
Potential energy (PE) is the energy a body possesses by virtue of its position with respect to other bodies in the field of gravity. (PE = mgh) where: m is the object's mass, g the acceleration of gravity and h is the object's height above ground level. Examples: Gravitational PE - Lake behind a dam - Hailstone suspended in a thunderstorm
Identify the major dates that correspond to the change of astronomical seasons in the Northern Hemisphere.
Sept 22-23 Autumn Equinox 0˚ Equator Dec 21-22 Winter Solstice 23½˚S Tropic of Capricorn Mar 21-22 Vernal Equinox 0˚ Equator June 21-22 Summer Solstice 23½˚N Tropic of Cancer
How will the heating rate of objects with a high specific heat value compare with objects with a lower specific heat value?
Since 'Specific Heat' is defined as the amount of energy needed to raise the temperature of 1 gram of substance 1 degree Celsius, the substances with the higher specific heat values will warm and cool slower than substances with smaller specific heat values. In other words water at a specific value of 1 cal/gram ˚C will warm and cool slower than land at a specific heat value of 0.3 cal/gram ˚C. That is why land will freeze quicker than bodies of water once we enter the cold season and land will thaw out before bodies of water once we enter the warm season.
If it is winter and January in New York City, what is the season during January in Sydney, Australia?
Since Sydney, Australia (33½˚ S Lat.) is in the Southern Hemisphere, it would be summer during the month of January. Seasons are opposite between the northern and southern hemisphere.
How would the heating of a surface area be affect after receiving it's first major snowfall of the season?
Since snow has a high albedo do to the whiteness of the snow, daytime surface temperatures would have a hard time recovering since 75 - 90% of the incoming solar radiation would be reflected off the snow pack and not used for heating of the lower atmosphere.
In the Northern Hemisphere, why are summers warmer than winters, even though the earth is actually closer to the sun in January?
The earth is 3.1 million miles closer to the sun in January than in July but due to the 23.5˚ tilt in the earth's axis the sun angle is at its lowest point in the Northern Hemisphere during the end of December and first part of January. The rays of sunlight that strike at an angle are spread across a greater surface area, and are therefore a less intense heat source than a beam of light that strikes the earth surface directly. Another important factor is that the daylight hours are shorter in the Northern Hemisphere during the winter season.
Explain how the atmosphere near the earth's surface is warmed from below.
The earth's atmosphere is warmed in part by 'Conduction' between the warm surface and a thin layer of air near the surface which will then rise causing thermals (Convection). Another aspect of warming is due to out going Infrared Radiation that is emitted by the earth's surface being absorbed by mainly water vapor and carbon dioxide in the lower atmosphere (Greenhouse Effect).
The earth's radiative equilibrium temperature is 0˚F but the earth's average surface temperature is 59˚F, why the difference?
The earth's radiative equilibrium temperature (0˚F) only takes into account the earth's surface which acts like a 'blackbody'. The earth's average surface temperature (59˚F) is higher because it includes the absorption and emitting properties of infrared (longwave) radiation by the earth's atmosphere which does not behave like a 'blackbody' but instead a 'selective absorber'.
If the earth's surface continually radiates infrared or longwave radiation, why doesn't it become colder and colder?
The earth's surface does not become colder and colder because objects not only radiate energy but they also absorb it. If an object radiates more energy than it absorbs, it gets colder; if the object absorbs more energy than it emits, it gets warmer.
What is the difference between the 'heat capacity' and 'specific heat' of an object? What are the "specific heat values" for water, ice and the earth surface?
The heat capacity of a substance is the ratio of the amount of heat energy absorbed by that substance to its corresponding temperature rise. The heat capacity of a substance per unit mass is called specific heat. In other words, specific heat is the amount of heat (calories) needed to raise the temperature of one gram of substance one degree Celsius. Specific Heat Values: Water → 1.0 calorie/gram ˚C Ice → 0.5 calorie/gram ˚C Earth surface (land) → 0.3 calorie/gram ˚C
What gases appear to be responsible for the enhancement of the earth's Greenhouse Effect?
The main cause of global warming appears to be an increase in carbon dioxide concentrations over the past 100 years primarily due to the burning of fossil fuels and to deforestation. Today, carbon dioxide concentrations continue to increase but other gases such as methane, nitrous oxide, and chlorofluorocarbons have collectively been shown to have an effect almost equal to that of carbon dioxide.
What is the earth's primary source of energy for the earth's atmosphere?
The sun. At an average distance of 93 million miles from the sun, the earth only intercepts a very small fraction of the sun's total energy output. However, the sun's radiant energy drives the atmosphere's weather and provides the earth with an annual average surface temperature of 59˚F.
Explain how radiational cooling at night produces a radiation temperature inversion.
The surface and air near the surface will cool quicker than the air above by emitting outgoing infrared radiation (radiation cooling). The warmer temperatures aloft do transfer some heat downward but the process is slow due to the air's poor thermal conductivity. Therefore, by late night or early morning the coldest air is found next to the surface, with warmer air above (radiational inversion).
What is the average decrease in temperature with height, or standard lapse rate, in the troposphere?
The temperature on average will decrease by 6.5˚C per 1000 meters (km) or 3.6˚F per 1000 feet as we rise in elevation within the troposphere. Example: The air temperature on the surface is 85°F. Lift the air to the 10,000 ft level. What is the air temperature at 10,000 ft? Since the temperature will decrease by 3.6°F per 1000 ft, the temp will drop a total of 3.6 X 10 = 36° 85 - 36 = 49°F at the 10,000 ft level.
Describe each of the controls of temperature. 1.Time of Year 2.Latitude 3.Land vs Water Distribution 4.Ocean Currents 5.Elevation
Time of Year - determines the location of the earth in its orbit around the sun which determines what season you are in Latitude - determines the amount of incoming solar radiation, slant angle of sun and duration of daylight hours, at a given latitude Land vs Water distribution - areas with more water (Southern Hemisphere) will have smaller seasonal temperature variations. Areas located in the middle of continents (Grand Forks) will have a much greater seasonal temperature variation than areas along the coast Ocean Currents - warm vs cold currents will affect coastal temperatures Elevation - higher elevations are colder due to decreasing temperatures with height but they also experience smaller temperature variations.
Why is the atmosphere not considered a 'blackbody'?
Unlike the earth, the atmosphere absorbs some wavelengths of radiation (Infrared) and is transparent to others (Visible Light). Objects that selectively absorb and emit radiation, like our atmosphere, are known as selective absorbers. The gases that are responsible for the absorption of outgoing Infrared Radiation are the Greenhouse gases of carbon dioxide and water vapor. Remember: A blackbody is any object that is a perfect absorber and a perfect emitter of radiation, at its given temperature. Therefore all of the radiation that is absorbed can also be emitted.
How does the amount of radiation emitted by the sun differ from that emitted by the earth when comparing the same time frame and area?
Using the Stefan - Boltzmann law, with the sun's surface temperature at 6000 K and the earth's average surface temperature at 288 K, one can calculate that the sun emits nearly 160,000 times more energy than the earth during a given time period and over the same size area
When looking at the variable gases in our atmosphere, which one shows the greatest variation at the earth's surface?
Water Vapor varies greatly from place to place and from time to time. Close to the surface in warm, steamy, tropical locations, water vapor may account for up to 4% of the atmospheric gases, whereas in cold arctic areas, its concentration may dwindle to a mere fraction of a percent.
List the two most abundant greenhouse gases in our atmosphere. What makes them greenhouse gases?
Water vapor and Carbon Dioxide: They both trap a portion of the earth's outgoing infrared radiation. Consequently, with everything else being equal, as the atmospheric concentration of CO2 increases, the amount of radiant energy trapped should increase resulting in average global surface air temperatures to increase over time.
How does weather differ from climate?
Weather is conditions of the atmosphere at any particular time and place. It is comprised of the elements of: air temperature, air pressure, humidity, clouds, precipitation, visibility, and wind. Climate is a specified interval of time that will give us the "average weather" for a region. It also includes the extremes of weather, therefore weather records are part of the climatology for a specific site or region.
Explain how "latent heat" plays an important role as a source of atmospheric energy and storm development?
When water vapor changes to a liquid (condensation) or ice crystal (deposition), a tremendous amount of heat energy is released into the environment due to the release of latent heat during the phase change. This latent heat provides energy for storm development, such as hurricanes, mid-latitude cyclones, and thunderstorms. Change 5 grams of water vapor to water will release 3000 calories of energy. (5 gr x 600 cal/gr = 3000 cal) Change 5 grams of water vapor to ice will release 3400 calories of energy. (5 gr x 680 cal/gr = 3400 cal)
Calculate the cooling degree-day for Grand Forks on a day with a minimum temperature of 71˚F and maximum temperature of 95˚F.
You must first calculate the mean (average) daily temperature. In this example, with a high of 95˚F and low 71˚F the average temperature is 83˚F. Then subtract the base temperature (65˚F) from the mean daily temperature (83˚F) and you get a cooling degree-day of: 83˚F - 65˚F = 18 units
Calculate the heating degree-day for Grand Forks on a day with a minimum temperature of -26˚F and maximum temperature of -10˚F.
You must first calculate the mean (average) daily temperature. With a high of -10˚F and low of -26˚F, the average temperature for the day would be -18˚F. Then subtract the mean daily temperature (-18˚F) from the base temperature of (65˚F) and you get a heating degree-day of: 65˚F - (-18˚F) = 83 units.