Exam #5 For Earth Science
What are the unit and measuring device of atmospheric pressure? (p. 361)
A barometer is a device used to measure barometric pressure. Meteorologists express pressure in inches or millimeters of mercury, referring to the height of the column of mercury in a barometer. They also express pressure in bars and millibars. A bar is approximately equal to sea level atmospheric pressure. A millibar is 0.001 of a bar.
Supersaturation
A condition in which the relative humidity of the air exceeds 100 percent.
Supercooling
A condition in which water droplets in air do not freeze even when the air cools below the freezing point.
What is fog?
Clouds that forms at or very close to the ground.
Relationship between evaporation, temperature, and latent heat
Evaporation absorbs heat and cools the water and air around it. Also, evaporation from any body of water cools the water and air around it. (The energy released / latent heat when water condenses into rain during a single hurricane can be as great as the energy released by several atomic bombs.)
Temperature changes with geography (figs. 18.16, 17, & 18)
Even though all locations at a given latitude receive equal amounts of solar radiation, some places have cooler climates than others at the same latitude. Such variations occur with latitude because winds and ocean currents transport heat from one region of Earth to another.
Definition of frequency and wavelength
Frequency is the number of complete wave cycles, from crest to crest, that pass by any point in a second (Short answer: How many wave cycles there are in a single second.) Wavelength, however, is the distance between successive wave crests (How far away each wave is from one another.)
Smog production (fig. 17.6, p. 367)
Smog forms in a sequential process. Step 1: Automobile exhaust reacts with air in the presence of sunlight to form ozone. Step 2: Ozone reacts with automobile exhaust to form smog.
Wind
The horizontal movement of air from an area of high pressure to an area of lower pressure; Horizontal airflow caused by pressure differences resulting from unequal heating of Earth's atmosphere. Winds near Earth's surface always flow from a region of high pressure toward a low-pressure region.
Conditions for cloud formation and precipitation.
Moisture condenses to form water droplets or ice crystals when moist air cools below its dew point; When moist air rises, it cools and forms clouds.
Relative Humidity
The ratio of the amount of water vapor in a given volume of air divided by the maximum amount of water vapor that can be held by that air at a given temperature, expressed as a percentage.
4 Layers (Spheres) in the Atmosphere
The temperature of the atmosphere changes with altitude. The 4 Layers / Spheres in the Atmosphere, from lowest to the Earth to the highest: Troposphere, stratosphere, mesosphere, thermosphere.
Where does cloud form, high-pressure or low-pressure? Where does air move, up or down?
When moist air rises, it cools and forms clouds; Clouds normally form at higher elevations where the air is not cooled by direct contact with the ground. Almost all cloud formation and precipitation occur when air cools as it rises; clouds form when air is forced upward at areas of low pressure.
Cyclone
a storm with heavy rains and high winds that blow in a circular pattern around an area of low atmospheric pressure; A low-pressure region with its accompanying system of inwardly directed rotating winds. In common, nonscientific usage the term often refers to a variety of different violent storms including hurricanes and tornadoes.
Carbon reservoirs
include fossil fuels, soils and sediments, solutes in oceans, plant and animal biomass, and the atmosphere. (Fig. 21.6, page 438)
Absolute Humidity
the mass of water vapor per unit volume of air that contains the water vapor, usually expressed as grams of water vapor per cubic meter of air; The mass of water vapor in a given volume of air, expressed in grams per cubic meter (g/m3)
Dry adiabatic rate
the rate of adiabatic cooling or warming in unsaturated air; the rate of temperature change is 1°C per 100 meters; The rate at which dry air cool adiabatically as it rises - 10 degrees Celsius for every 1,000 meters above sea level. Rising air cools at the dry adiabatic lapse rate until it cools to its dew point and condensation begins.
Wet adiabatic rate
the rate of adiabatic temperature change in saturated air; the rate of temperature change is variable, but it is always less than the dry adiabatic rate; The rate at which rising moist air cools adiabatically after it has reached its dew point and condensation has begun—varying depending on moisture content from 5 degrees Celsius to 9 degrees Celsius for every 1,000 meters it rises
Anticyclone
the rotation of air around a high-pressure center in the direction opposite to Earth's rotation; A high-pressure region with its accompanying system of outwardly directed rotating winds that develop where descending air spreads over Earth's surface.
Vaporization
The vaporization of water absorbs heat and, therefore, cools both the surface and the surrounding air. In addition, vaporization adds moisture to the air.
Fog Characteristics for Each Type
Advection Fog - Occurs when warm, moist air fro the sea blows onto cooler land. The air cools to its dew point, and water vapor condenses at ground level. Radiation Fog - Occurs when Earth's surface and air near the surface cool by radiation during the night. A ground fog of this type typically "burns off" in the morning; particularly common in areas where the air is polluted because water vapor condenses readily on the tiny particles suspended in the air. Evaporation Fog - Occurs when air is cooled by evaporation from a body of water, commonly a lake or river; common in late fall and early winter, when the air has become cool but the water is still warm. The water evaporates, but the vapor cools and condenses to fog almost immediately upon contact with the cool air. Upslope Fog - Occurs when air cools as it rises along a land surface; they occur both on gradually sloping plains and on steep mountains.
Types of Fog
Advection Fog, Radiation Fog, Evaporation Fog, Upslope Fog.
Relationship between albedo and temperature
Albedo is the reflectivity of a surface; surfaces that reflect more light have a higher albedo. Albedo in latin refers to "whiteness," which makes sense, since certain landscape features such as snowfields and glaciers have high albedos and reflect 80 to 90 percent of sunlight. Clouds have the second highest albedo and reflect 50 to 55 percent of sunlight. The temperature balance of the atmosphere is profoundly affected by the albedos of the hydrosphere, geosphere, and biosphere. If Earth's albedo were to rise by growth of glaciers or cloud cover, the surface of our planet would cool. Alternatively, a decrease in albedo (caused by the melting of glaciers) would cause warming.
Relationship between air density and altitude (refer to fig. 17.6)
Atmospheric pressure decreases with altitude. One-half of the atmosphere lies below an altitude of 5,600 meters.
How to change relative humidity?
By cooling the air without adding or removing any water vapor. Because cold air holds less water vapor than warm air holds, the relative humidity increases even though the amount of water vapor remains constant. (p. 387)
Cloud Type Definitons (Illustration on page 393)
Cirrus - clouds that resemble wisps of hair blowing in the wind; the air is so cold at these elevations that cirrus clouds are composed of ice crystals rather than water droplets. Stratus - horizontally layered, sheetlike clouds. They form when condensation occurs at the same elevation at which air stops rising and the clouds spread out into a broad sheet; they form dark, dull-gray, overcast skies that may persist for days and bring steady rain. Cumulus - Fluffy, white clouds that typically display flat bottoms and billowy tops. Stratocumulus - Low, sheet-like clouds with some vertical structure. Cumulonimbus - A towering rain cloud; commonly produces intense rain, thunder, lightning, and sometimes hail. Nimbostratus - A stratus cloud from which rain or snow falls. Altostratus - A high stratus cloud.
Cloud Identification / Types of Clouds (p. 393)
Cirrus, Stratus, Cumulus, Stratocumulus, cumulonimbus, nimbostratus, altostratus.
Temperature changes with latitude (fig. 18.11, p. 379)
If a light shines from directly overhead, the radiation is concentrated on a small circular area. However, if the light shines at an angle, or if the surface is tilted, the radiant energy is dispersed over a larger, elliptical area, but is overall less concentrated and the intensity is reduced.
Greenhouse Effect (fig. 18.7, p. 375)
Natural situation in which heat is retained in Earth's atmosphere by carbon dioxide, methane, water vapor, and other gases; An increase in the temperature of the planet's surface caused when infrared-absorbing gases in the atmosphere trap energy from the Sun.
Ozone production in stratosphere (p.363)
Oxygen molecules (O2) in the stratosphere absorb energetic ultraviolet rays from the Sun. The radiant energy breaks the oxygen molecules apart, releasing free oxygen atoms. These free oxygen atoms then recombine to form ozone (O3). Ozone absorbs ultraviolent energy more efficiently than oxygen does, and the absorption of UV radiation by the ozone warms the upper stratosphere. Ozone concentration declines in the upper portion of the stratosphere. The ozone in the upper atmosphere protects life on Earth by absorbing much of this high-energy radiation before it reaches Earth's surface.
Photosynthesis
Primitive bacteria evolved the ability to harness the energy in sunlight and produce organic tissue; Photosynthesis is the foundation for virtually all modern life; During photosynthesis, organisms convert carbon dioxide and water to organic sugars. They release oxygen as a by-product (released as a result of a process). Book Definition: The process by which chlorophyll-bearing plant cells convert carbon dioxide and water to organic sugars, using sunlight as an energy source; oxygen is released in the process.
Relationship between plate tectonics and carbon dioxide levels
Refer to textbook (figs. 21.10 & 11)
***The Earth's atmosphere through time (table 17.1)
Refer to textbook.
Heat absorption: rock vs. water
Rock absorbs heat only at its surface, and the heat travels slowly through the rock. As a result, heat concentrates at the surface. However, heat disperses more effectively through water because 1.) solar radiation penetrates several meters below the surface of the water, warming it to this depth and 2.) water is a fluid and transports heat by convection.
What is adiabatic temperature change?
Temperature changes caused by compression or expansion of gas, that occur without gain or loss of heat.
Consequences of greenhouse warming
Temperature effects on agriculture, precipitation and soil-moisture effects on agriculture, extreme weather events, changes in biodiversity, melting of arctic sea ice and glaciers, acidification of the oceans, sea level change, and effects on people. (p. 446)
Coriolis effect
The Coriolis Effect deflects winds to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. (fig. 19.15, page 397)
Specific Heat
The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree celcius
Definition of Latent Heat (stored heat)
The energy released or absorbed when a substance changes from one state to another by melting, freezing, vaporization, condensation, or sublimation.
Definition of electromagnetic spectrum and its sequence.
The entire range of electromagnetic radiation from very-long-wavelength (low frequency) radiation to very-short-wavelength (high frequency) radiation; the continuum of radiation of different wavelengths and frequencies.
What are major greenhouse gasses? Include properties.
The major greenhouse gases are water, carbon dioxide, and methane. Water - The most abundant greenhouse gas in Earth's atmosphere. Carbon Dioxide - Its abundance in the atmosphere can vary as a result of several natural and industrial processes. Methane - Large quantities are released by industry and agriculture.
Saturation
The maximum amount of water vapor that air can hold.
Why sky is blue? (p. 374)
The tiny particles in the upper atmosphere (nitrogen and oxygen) scatter (reemit in all directs) the high frequencies (blue/violet). Our eyes are more sensitive to blue so we see the sky as blue; The sky is blue because of scattering; the blue components of sunlight scatters more than other frequencies and colors the atmosphere. Atmospheric gases, water droplets, and dust particles scatter sunlight in all directions, which is why sunlight is projected on both windows located on two opposite sides of a building.
Characteristics of the 4 Spheres within the Atmosphere
Troposphere - The layer of air closest to Earth; the layer we live in. All of the water vapor and clouds exist in this layer, and almost all weather occurs here; some solar energy from continents and oceans are absorbed by the lower parts of the troposphere. Stratosphere - The layer of air above the troposphere; the boundary between the troposphere and the stratosphere. The stratosphere is heated primarily from above by direct incoming solar radiation. Mesosphere - The layer of air that lies above the stratopause, extending upward from about 55 kilometers to about 80 kilometers above Earth's surface; It is the second zone of declining temperature in Earth's modern atmosphere. Little radiation is absorbed in the mesosphere, and the thin air is extremely cold. Thermosphere - An extremely high and diffuse region of the atmosphere lying above the mesosphere, from about 80 kilometers upward; furthest from the Earth. The atmosphere in this level absorbs high-energy X-rays and ultraviolet radiation from the Sun. The temperature in the upper portion of the thermosphere is just below freezing; not extremely cold by surface standards.
What is threshold mechanism
Where the slightest change to a factor creates a large effect.; a slight perturbation offsets the entire thing. (Example on page 448)
Isobars
a line on a map connecting points having the same atmospheric pressure at a given time or on average over a given period; Lines on a weather map connecting points of equal air pressure. (p. 397)
What causes El Nino?
Winds blow from the west (from Asia), reducing the equatorial current. This reduces upwelling and warms the water in the eastern Pacific; It is an episodic weather pattern occurring every 3 to 7 years in which the trade winds slacken in the Pacific Ocean and warm water accumulates off the coast of South America and causes unusual rains and heavy snowfall in the Andes.
How to measure climate change?
You can measure climate change through historical records, tree rings, plant pollen, oxygen isotope ratios in glacial ice, glacial evidence, plankton and isotopes in ocean sediment, and the rock and fossil record. (Pages 434-436)
What is feedback mechanism?
a cycle of events in which information from one step controls or affects a previous step; When a small initial perturbation affects another component of Earth's systems, which amplifies the original effect, which perturbs the system ever more. Think of dominos falling on top of one another. Each one knocks down another in a chain of events.