ATMO Quiz 170

If the height contours of an upper-level weather map have labels between 5100 and 5700 m, what pressure surface are we most likely looking at?

500 hPa

If the temperature at the bottom of Mount Rainier (elevation 0 meters, or sea-level) is 15°C, what is the approximate temperature at the top of Mount Rainier (elevation 4300 meters = 4.3 km)? Use the average environmental lapse rate value of the prior question.

6.5 °C/km*4.3 km = 27.95 °C 15°C - 27.95 °C = -12.95°C (answer: -12.95°C)

Describe two different types of thermometers. Explain in each case what the instrument actually measures and how the measured variable is related to temperature.

A bimetallic strip, for example, is made of two thin pieces of different types of metal attached to each other. Because the metals expand and contract at different rates, the combined strip bends when the temperature changes. If the tip of the metal strip is made to bend toward a temperature scale, the device can be calibrated and turned into an instrument. Radiometers measure the radiation emitted by bodies. Because the emitted radiation is a function of the temperature of these bodies, we can once again indirectly deduce their temperature.

What is the numerical value of absolute zero in kelvin, in degrees, Celsius, and in degrees Fahrenheit

Absolute zero is 0 K C= -273.15 F=--459.67F

Is air a good conductor or a good insulator? How about a vacuum? Why?

Air is a very poor conductor but a very good insulator. It is because the arrangement of particles of air is far apart, which makes the transfer of heat slow. Vacuum is often considered to be the best known insulator because vacuum lacks particles needed to transfer heat.

Define the term "albedo" and provide an example of a surface with high albedo, as well as an example of a surface with low albedo.

Albedo is the fraction (or percentage) of incoming sunlight that is reflected by an object or surface. An example of a surface with high albedo would be fresh snow, while an example of a surface with low albedo would be grass.

Provide an example of a good reflector of visible light, and an example of a good absorber of visible light.

An example of a good reflector of visible light is the color white because it reflects almost all of the visible light. An example of a good absorber of visible light is the color black. because it absorbs almost all of the visible light.

Provide one example each of a positive feedback loop and a negative feedback loop

An example of a positive feedback loop is ice-albedo feedback An example of a negative feedback loop is Planck feedback

Provide an example of convection (i.e., convective motion) taking place in your house, and another example of convection taking place in nature.

An example of convection is the boiling of water and the warming of the air.

Describe the average vertical distribution of pressure and temperature in the atmosphere

As altitude decreases, pressure in the atmosphere increases and temperature increases. As altitude increases, pressure in the atmosphere decreases and temperature decreases.

Explain how a mercury barometer works. In particular, explain what happens when atmospheric pressure increases/decreases.

As the weather changes, air moves around, resulting in atmospheric pressure changes at a given location. We measure these atmospheric pressure changes using mercury barometer. If atmospheric pressure increases, the mercury level rises in the tube. Conversely, when a storm approaches and atmospheric pressure drops, a shorter column of mercury is required to balance the weight of the atmosphere, and the mercury level drops.

Which gas contributes the most to the greenhouse effect?

Carbon Dioxide. Carbon dioxide (CO2) is the primary greenhouse gas emitted through human activities. In 2018, CO2 accounted for about 81.3 percent of all U.S. greenhouse gas emissions from human activities.

Explain how carbon is cycled through the Earth system through photosynthesis and decay of plant matter.

Carbon dioxide can be removed from the atmosphere by photosynthesis, by which CO2 combines with water (H2O) to form organic matter (CH2O) and release oxygen (O2). CO2+H2O→(light)→CH2O+O2 Conversely, through combustion or decay (i.e., oxidation), organic matter turns into water vapor and carbon dioxide. CH2O+O2→H2O+CO2

Why do most clouds appear white? Why do some clouds appear darker gray?

Clouds with a white or light grey shading in an infrared satellite image are colder and therefore higher in the atmosphere, while clouds with a dark gray shading are warmer and therefore lower in the atmosphere.

How do we differentiate a temperature front from an air mass on a temperature map?

Coloring and contouring the temperature map allows us to quickly identify the air masses, where the temperature is relatively uniform.

Define the following terms: conduction (of heat), an insulator, vacuum.

Conduction is the transfer of heat by contact, collision, and transfer of molecular vibrations. Insulator is a material that does not easily transmit energy, such as electric current or heat. Vacuum is an enclosed space from which matter, especially air, has been partially removed so that the matter or gas remaining in the space exerts less pressure than the atmosphere.

Explain why the temperature increases with height in the stratosphere.

Due to the presence of ozone and the absorption of ultraviolet radiation in stratosphere, the temperature increases with height. This inverse temperature change with height is called as temperature inversion.

Why do land and ocean appear dark gray in an infrared satellite image?

Earth does not emit visible radiation, the only light that will be measured by such a sensor is visible light from the sun reflected by bright features on Earth, such as clouds, ice, snow, and to some extent bright land areas.

Explain why the length of day and night changes throughout the year at most locations on Earth.

Earth is tilted toward the sun in summer, a given location in the summer hemisphere spends more time on the day side than on the night side. In other words, the days are longer than the nights, which means that such a location is absorbing heat during a longer time period in summer than in winter.

Describe the forces applied to a satellite in orbit around Earth and explain the special conditions required for a geostationary orbit.

For the satellite to stay in orbit, the gravitational pull of Earth needs to balance the centrifugal force exactly. The geostationary satellite must be in the equatorial plane at about 36 000 km from Earth's center which is the distance where the gravitational pull of the Earth is equal to the centrifugal force of the satellite.

Describe the differences between geostationary and polar-orbiting satellites.

Geostationary satellites are stationary with respect to a specific location on Earth, so that they constantly observe that same location over time. Polar-orbiting satellites orbit Earth in a pole-to-pole direction and provide valuable information about the polar regions, which are not captured by geostationary satellites.

Describe two types of rain gauge used in meteorology.

In a tipping bucket, water is collected by a funnel and falls onto a tipping plate that tips when enough water has accumulated in the bucket. Funnel, a simpler type of rain gauge, also collects raindrops and magnifies the rain accumulation into a thinner cylinder so that the total depth may be accurately read on the scale.

Explain why the tropics are on average warmer than the poles.

In the tropics, the sun is high in the sky, and the sun rays tend to be concentrated over smaller areas compared to the polar regions, where the sun is low in the sky and sun rays are spread out over larger areas.

Provide three examples of electromagnetic waves and describe what differentiates them.

Infrared radiation have longer wavelengths and carry less energy than visible light. Ultraviolet radiation have shorter wavelengths and carry more energy than visible light Gamma waves have the shortest wavelengths and have the highest frequency of all known electromagnetic waves.

Explain what an isobar is.

Isobars are contours of pressure and each isobar represents a particular value of pressure - typically at a 4 hPa interval.

Explain what an isotherm is.

Isotherms are lines of constant temperature on a surface temperature map.

What was the average concentration of atmospheric carbon dioxide (CO2), just before the start of the Industrial Revolution (circa: 1750-1800)? What is it today? You will need to search the current levels online. Google "Keeling Curve".

Just before the start of Industrial Revolution (circa:1750-1800), the average concentration of atmospheric carbon dioxide was 280 ppm. Now, the average concentration of atmospheric carbon dioxide is 417 ppm.

What are the different units of pressure used in meteorology? What is a pressure of 1013 hPa expressed in millimeters of mercury?

Pascal (Pa); millibars (mb); pounds per square inch (psi); inches of mercury (Hg) mm = hPa × 0.75 mm = 1013hpa × 0.75 answer: 759.8 mm

Explain the difference between sustained wind and wind gust.

Sustained winds are the steady or the average wind speeds over a period of time. Wind gusts are the sudden big wind speeds at last for about 5 seconds.

What is a "temperature inversion?"

Temperature normally decreases with height, but the situation in the stratosphere is the inverse of what it should be. Temperature Inversion is a temperature change due to the presence of ozone and the absorption of ultraviolet radiation that causes the temperature to increase as height increases in the Stratosphere.

In what range of wavelengths does Earth mostly emit the most radiation?

The Earth emits most of its radiation in a wavelength band between 0.5 and 30.0 micrometers (μm).

Explain how the altitude of cloud tops can be inferred from infrared satellite images if you know the temperature profile of the troposphere.

The amount of infrared radiation emitted by cloud tops tells us their temperature, which in turn tells us their altitude. Because a high altitude cloud is cooler, and a low altitude cloud is warmer.

What are the two main permanent gases of the atmosphere? What is their ratio?

The atmosphere mostly contains molecular nitrogen, N2 (78%) and molecular oxygen, O2 (21%).

If a trough is adjacent to a ridge on a surface pressure map, which is indicating lower pressures and which is indicating higher pressures?

The axis of the trough is a line of relative minimum pressure compared to the higher values of pressure down the slopes on each side of the crest. At the center of the trough, the pressure should be the lowest compared to its surrounding contours. The crest of the ridge is a line of relative maximum pressure, compared to the lower values of pressure down the slopes on each side of the crest. At the center of the ridge, the pressure should be the highest compared to its surrounding contours.

What is the difference between the greenhouse effect and global warming?

The greenhouse effect is a natural process by which Earth has maintained a slowly varying equilibrium temperature throughout its history, in response to slowly varying greenhouse gas concentrations, while global warming is the effect of the enhancement of the greenhouse effect by anthropogenic increase of certain greenhouse gas concentrations, such as carbon dioxide and methane.

What feature of the atmospheric absorption spectrum do we call the "infrared atmospheric window?" Explain why it is important for the energy balance of the Earth system.

The infrared atmospheric window refers to a region of the Infrared spectrum where there is relatively little absorption of terrestrial thermal radiation by atmospheric gases. The window plays an important role in the atmospheric greenhouse effect by maintaining the balance between incoming solar radiation and outgoing IR to space. If this infrared window did not exist, the radiative energy received from the sun would be reemitted by Earth and absorbed by the atmosphere, and the planet would be warmer than it is.

On what date do we have the longest day in Tucson (the most daylight hours)? On what date do we have the longest night (the most hours of darkness)? On what days do we have day and night of equal length (12 hours of daylight, 12 hours of darkness)?

The longest day in Tucson would be on June 21. The longest night in Tucson would be on December 21. The days when day and night would have equal length would be on March 21 and September 21.

Explain why the formation of an ozone layer was crucial to the development of life on Earth 500 million years ago.

The ozone layer absorbs UV radiation from the sun and prevents much of it from reaching the surface, where it would damage life (plants and animals) and cause severe problems for us, including skin cancer and eye cataracts. Land areas on Earth only became habitable when the atmosphere contained enough oxygen that significant amounts of stratospheric ozone (O3) formed, which is highly efficient at absorbing ultraviolet radiation.

What factors can influence the maximum and minimum temperatures recorded during the day or night?

The presence of clouds can prevent incoming solar radiation from heating the surface, limiting high temperatures during the day. It can also prevent infrared radiation from escaping to space, limiting low temperatures at night.

Explain why and how the ozone layer was partly destroyed during the second half of the twentieth century.

The reduction in ozone concentration was found to be due to the emission of chlorofluorocarbons (CFCs) into the atmosphere. CFCs are synthesized gases containing chlorine that were used as refrigerants, propellants in spray cans, solvents, and as blowing gas to make foam.

Explain why the sky is blue, and why sunsets are often orange or red in color.

The sky is blue because when you look up at the atmosphere, away from the sun, you see sun rays that have been deflected by nitrogen or oxygen molecules, either once or multiple times. When the sun is low on the horizon, at sunset or sunrise, sunlight must travel a longer distance through the atmosphere before reaching your eyes, and most of the blue light has been scattered away, leaving only longer wavelengths to reach you, such as yellows and reds.

Explain why maximum temperatures are often recorded in the middle afternoon, and not at noon.

The sun is closer to the Earth during middle afternoon, so it would be the hottest time of the day, while at noon, it was still getting warmer because the Earth was still emitting infrared radiation.

What is the average environmental lapse rate in the troposphere?

The temperature drops at an average rate of about 6.5 °C/km (or 3.6 °F per thousand feet).

explain what absolute zero means

The theoretical temperature at which all molecular motion is presumed to cease

What is the typical range of atmospheric pressure measured at sea level in the midlatitudes? At what altitude and pressure do we typically find the tropopause in the midlatitudes?

The typical range of pressure at sea level is about 980 to 1030 hPa. Tropopause is typically found at an altitude of 12km, with the pressure of 200 hPa.

Explain why locations on land typically experience larger temperature variations (i.e., a wider temperature range) than locations on the ocean.

Water bodies experience smaller temperature variations than land surfaces due to turbulent mixing, deeper penetration of sunlight, the evaporation of water, and a higher heat capacity. Therefore, the overlying air and coastal locations also experience a smaller diurnal and seasonal cycle than inland, continental locations.

Provide three examples of variable gases and explain, in each case, why they are considered "variable."

Water vapor - The concentration of water vapor can change greatly in time and space. It is typically greater over the ocean and less over deserts, and it fluctuates at a given location as relatively drier and moister air masses move around with weather systems. Carbon dioxide (CO2) - The concentration of Carbon Dioxide also varies in time and space. It decreases annually in northern hemisphere spring and summer, when vegetation grows and takes up CO2 during photosynthesis on land areas of the northern hemisphere and increases in fall and winter in the northern hemisphere, when vegetation dies, decays, and releases the CO2 back into the atmosphere. Methane (CH4) - Methane has even smaller concentrations and can be found in elevated concentration near sources such as natural gas reserves, swamps, rice paddies, garbage dumps, and livestock.

Explain how water vapor contributes to increasing the average temperature of the atmosphere (i.e., the so- called "greenhouse effect")? What other gases contribute to the greenhouse effect?

Water vapor in the atmosphere absorb energy in the form of infrared radiation and maintain Earth's surface at a higher temperature than would be the case without an atmosphere. Other gases that contributes to the greenhouse effect would be carbon dioxide, methane, ozone, and nitrous oxide.

Explain why we experience seasons in each hemisphere. Describe the tilt of Earth's axis with respect to its plane of rotation and the consequences on the amount of solar radiation received by each hemisphere at different times of the year.

We experience seasons because of the interaction of solar radiation with Earth. The sun is higher in the sky in summer, and lower in winter. Therefore, solar radiation is concentrated onto a smaller area in summer, which results in more energy being absorbed per unit area, and higher temperatures. In winter, solar radiation is spread out over a larger area, which results in less energy being absorbed per unit area, and lower temperatures. In summary, seasons are due to the tilt of Earth's axis with respect to the ecliptic plane (i.e., the plane of Earth's rotation around the sun), which brings the summer hemisphere under more direct solar radiation during longer days, and the winter hemisphere under less direct radiation during shorter days.

Describe how weather radar works. In particular, explain how the distance between the radar and the precipitation can be calculated, and then mapped.

Weather radars emit radio waves. Some of these waves are transmitted through the atmosphere and are lost if they do not encounter any obstacle. If precipitation is present on their path, however, the raindrops will reflect some of the waves back to the radar, where the returned energy can be measured and analyzed. The return signal is an indirect measurement of precipitation. It contains two pieces of information. First, more precipitation causes more reflected signal. Therefore, the radar can be used to estimate the rate of precipitation. Second, by calculating the time it took for the signal to reach the raindrops and come back, we can estimate the distance between the radar and the precipitation, and we can indeed map the structure of the precipitation around the radar. Therefore, a radar provides information about both the location and the intensity of precipitation.

How much additional pressure does your body experience when you dive 10 m underwater? If you dive 30 meters underwater, how much total pressure does your body experience? (Do not forget to add the contribution of the atmosphere to the total pressure.) Provide your answer in bars, and in millibars.

When you dive 10 m underwater, your body experience an additional 1 bar of pressure. For each additional 10 m layer of ocean, we will add another bar of pressure. So if you dive 30 m underwater, your body experiences 4 bars of pressure or 4000 millibars.

Describe how wind speed and direction are typically measured at weather stations.

Wind speed is measured with an anemometer. The most common type is the cup anemometer. As the cups catch the wind, the spindle rotates, and the rate of rotation of the spindle is proportional to the wind speed. Wind direction is measured using a wind vane. The vane points toward the direction that the wind is coming from, which is why meteorologists report wind direction as the direction that the wind is coming from.

Is the greenhouse effect detrimental to Earth's atmosphere, or to life on Earth? Why?

Yes, the greenhouse effect is tending to cause harm to Earth's atmosphere and to life on earth because increasing greenhouse gases means more absorption of infrared radiation, and therefore more heat and a higher temperature for Earth. This effect would eventually result to the melting of ice and snow which will result in floods, destruction of ecosystems and more.

Convert a wind speed of 25 knots to meters per second, kilometers per hour and miles per hour.

meters per second = knots / 1.944 kilometers per hour = knots * 1.852 miles per hour = knots * 1.151 answer: 12.86 m/s; 46.3 km/h; 28.77mph