Study Guide for Exam 2

ESCI 1101

Chapter 7: Air Masses and Weather Systems

1. What are the primary lifting mechanisms in the atmosphere?
   1. Convective Lifting: air near the ground becomes warmer than the surrounding air, reducing its density and causing it to rise.
   2. Orographic Lifting: large air masses are forced to rise by a topographic barrier. The windward slope is wet, while the leeward side is dry by causing the rain shadow effect.
   3. Frontal Lifting: cold air forces warmer, lighter air to rise.
2. What are airmasses and how are they classified?
   1. Airmasses are large bodies of air that are relatively homogenous in temperature and humidity that have a significant impact on the weather. They are classified by their location (maritime or continental) and by the climate of the place where they form.
   2. They form over a source region: a nearly homogeneous surface of land or ocean over which an air mass acquires its temperature and humidity characteristics.
3. What are the primary differences between cold and warm fronts (precip., steepness, vertical structure, cloud types)
   1. Primary Differences between cold and warm fronts:
      1. Cold Fronts:
         1. Precipitation: intense precipitation (heavy showers of rain or snow)
         2. Steepness: cold fronts are steeper than warm fronts which forces the warm air up
         3. Vertical structure: There is strong vertical development of clouds which can manifest as a line of showers and thunderstorms.
         4. Cloud types: cumulus, nimbostratus, cumulonimbus, stratocumulus (cauliflower clouds)
      2. Warm Fronts:
         1. Precipitation: There is mostly just some drizzle, but nowhere near as heavy showers as cold fronts
         2. Steepness: these have a much gentler slope than cold fronts
         3. Vertical Structure: the vertical uplift is not as strong along warm fronts
         4. Cloud types: stratus, altostratus, cirrostratus, cirrus (very stringy)
4. What do midlatitude storms look like in terms of structure?
   1. Midlatitude cyclones are frontal zones of strong temperature contrasts. These storm systems travel with westerly winds of the midlatitudes and the polar front, typically consisting of a cold front, a warm front, and three sectors (cold, warm, and cool).
5. What is an occluded front, what does it signify?
   1. An occluded front is a plane where a cold front overtakes a warm front and pushes the warm air up. It is shown as a purple line with semicircles and triangles, and it signifies incoming precipitation and the formation of cumulonimbus and nimbostratus clouds.
6. What are updrafts and downdrafts?
   1. Updrafts are upward-moving air currents that can characterize a storm’s early development, during which warm air rises to the level where condensation begins, and precipitation starts to develop.
   2. Downdrafts are downward-moving air currents that originate at high levels and contain cold, dense air that spreads out at the ground as a cold air wedge
7. What is lightning?
   1. Lightning is the occurrence of a natural electrical discharge, the separation of electric charge and generation of an electric field within a thunderstorm. The top of the cloud has a positive charge, and the bottom of the cloud is negatively charged.
      1. Positive lightning: the stronger form of lightning and the flash duration is larger and stems from the top layer of the cloud.
      2. Negative lightning: the weaker form of lightning that doesn’t travel as far and comes from the bottom layer of the cloud.
8. What causes thunder?
   1. Thunder is the sound that comes from lighting quickly heating up the air around lightning and the air then cools around it and causes a shockwave (thunder).
9. Which regions of the U.S. see the most thunderstorm days per year and why?
   1. The Florida peninsula (80-100 days), the Gulf Coast (60-90 days), and the mountains of New Mexico (50-80 days) see the most thunderstorms per day. Florida gets the most thunderstorm days year since it surrounded by water, which provides moisture and water vapor to feed thunderstorms.
10. Understand the 3 basic stages to thunderstorm development and why each occurs
    1. 1^st stage: In the development stage there is a cumulus cloud that is pushed upward by an updraft or moisture and unstable air.
    2. 2^nd stage: In this mature stage the storm is fully formed, and it produces rain, lightning, and sometimes hail or tornadoes. It enters this stage when the updraft continues to feed the storm, but then precipitation falls out of the storm and creates a downdraft.
    3. 3^rd stage: The dissipating stage is when the storm weakens and breaks a part due to a lack of updraft and a dominance of downdraft.
11. Understand the basics of tornado development.
    1. Tornados are rapidly rotating columns of air that extend from a storm (usually a supercell) to the surface. The development of these tornados is related to the temperature differences across the edge of downdraft air wrapping around the mesocyclone.
12. When is the peak in tornado formation in the US?
    1. The peak time for tornados in the US is in the spring and the summer between the months of April and June with May having the most recorded tornados.
13. What is the EF scale?
    1. The EF scale stands for the Enhanced Fujita Scale which measures the damage and estimated wind speeds and assigns ratings to them, but it does not measure their size.
14. What conditions need to be met for hurricanes to develop?
    1. There needs to be warm water that the hurricane can feed off. These hurricanes start with warm water that is found near the equator that evaporates and forms warm air. The wind blowing over this warm water exacerbates the evaporation, the warm air rises forming cumulonimbus clouds, the winds gather the clouds and gain speeds up to 74 mph and is then classified as a hurricane.
15. What is the eye of the storm?
    1. The eye of the storm is at the center of the hurricane, and it is an area of calm, clear, and usually warm but rainless air and there are also strong winds surrounding it.
16. What is the eyewall? Rainbands?
    1. The eyewall is the area of strongest winds, intense thunderstorms, and heavy rain that surrounds the eye of a hurricane.
    2. Rainbands are spiral bands of clouds that include rain showers and thunderstorms that extend out from a hurricane’s eye wall.
17. When does a tropical system receive a name?
    1. A tropical system receives its name when the storm has sustained winds of 39-74 mph.
18. What is storm surge? Which types of areas are more vulnerable to it?
    1. Storm surge is when the sea level rises, and the hurricane brings the ocean water onshore from its intense winds and causes major flooding. Cities that are near bodies of water like coastal cities and have coastlines that curve inward.
19. Which months of the year see the most hurricanes in the Atlantic and why?
    1. The Atlantic hurricane season is from June 1-November 30 and is when you see the most hurricanes because in these seasons the ocean water is the warmest and there are weak vertical winds shear.

Chapter 8: Global Climates and Climate Change

1. What is climate? What is a climate region?
   1. Climate is the conditions of the atmosphere at a particular location over a long period of time and it is a long-term summation of the atmospheric elements including solar radiation, temperature, humidity, precipitation, atmospheric pressure, and wind.
   2. Climate region is a region defined by the similarity of climatic conditions in the area within its boundaries.
2. What are the primary components that dictate the climate of a region?
   1. The temperature and the precipitation levels of the region are the primary components that dictate the climate of a region. The atmosphere, the biosphere, cryosphere, hydrosphere, and some human influences dictate the climate.
3. What is the Koppen Climate Classification system?
   1. The Koppen Climate Classification system was created by a German scientist that noticed that the type of vegetation in a region depended largely on climate. This system classifies climates in six major groups that are dependent on vegetation, temperature, and precipitation data of the area.
4. Know the 6 primary climate regions and their differences
   1. A- Tropical Climates
      1. These climates extend north and south from the equator to about 15-25 degrees latitude.
      2. All months here have average temperatures greater than 64 degrees Fahrenheit
      3. Annual precipitation: 59 inches
   2. B- Dry Climates
      1. The potential evaporation and transpiration exceed the level of precipitation (they are very dry)
      2. 20-35 degrees north and south of the equator
      3. Often surrounded by mountains (mid-latitudes)
   3. C- Moist Subtropical Mid-Latitude Climates
      1. Warm and humid summers with mild winters
      2. Extends from 30-50 degrees latitude (eastern and western borders)
      3. Typically have mid-latitude cyclones (convective thunderstorms) dominate the summer months
   4. D- Moist Continental Mid-Latitude Climates
      1. Warm to cool summers and cold winters
      2. The average temperature of the warmest month is greater than 50 degrees Fahrenheit
      3. While the coldest month temperatures are less than 27 degrees Fahrenheit
      4. Severe winters
   5. E- Polar Climates
      1. Year-round cold temperatures (the warmest month is less than 50 degrees Fahrenheit)
      2. Found on northern coastal areas
   6. H – Highlands
      1. Climates that are a result of elevation
      2. Occur in mountainous terrain with rapid elevation changes
5. What region do we live in and why?
   1. North Carolina in the Humid Subtropical Climate (cfa) as the mountains act as a shield to block low temperatures and there are storms from the Midwest.
6. Know the different tropical climate systems (rainforest/monsoon/savanna)
   1. Rainforest:
   2. Monsoon:
   3. Savanna:
7. What is the difference between tundra, icecap, and icesheet climates?
8. How are a desert and steppe defined?
9. What is Climate Change?
10. What does a volcanic eruption mean for planetary temperatures?
11. Understand the basics of the greenhouse effect and global warming – natural and man-made
12. What have global temperatures done over the last century?

Chapter 16: Subsurface Water and Karst

1. What are the two primary pathways for surface water?
2. What is infiltration? Percolation?
   1. Infiltration: the process of water seeping downward into the soil or other surface materials
   2. Percolation: subsurface water moving downward to lower zones by the pull of gravity
3. What are the 3 types of soil moisture and how are they different? (Hygroscopic, Capillary, Gravitational)
   1. Hygroscopic: water held tightly to soil particles and surfaces due to molecular attraction forces> It is the smallest fraction of soil moisture and is held in the form of a thin film around the soil particles.
   2. Capillary: this moisture is held by surface tension as a film of moisture on the surface of soil particles and pads and it may move through the soil under these surface tension forces. Some of it may be used by plants.
   3. Gravitational: free moisture that moves through soil due to the force of gravity. This is water held in large soil pores and rapidly drains out under the action of gravity within a day or so after rain.
4. What is the zone of aeration? Saturation?
   1. Zone of aeration: the uppermost layer of subsurface water where pore spaces typically contain both air and water
   2. Zone of saturation: subsurface water zone in which all voids in rock and soil are filled with water; the top of this zone is the water table
5. What is a permeable/impermeable layer?
   1. Permeable layer: is a layer of the soil that has a greater number of large, well-connected pore spaces
   2. Impermeable layer: this layer has fewer, smaller pores that are poorly connected
6. What is an aquifer? Aquiclude?
   1. Aquifer: a rock layer that is a container and transmitter of groundwater; it is both porous and permeable
   2. Aquiclude: rock layer that restricts flow and storage of groundwater; it is impermeable and nonporous
7. What is the water table? How does well water work?
   1. The water table is the upper limit of the zone of saturation below which all pore spaces are filled with water.
   2. A well is an artificial opening that reaches the zone of saturation for the purpose of extracting groundwater. A well works by collecting groundwater from a source, like an aquifer, and moving it through your home’s plumbing.
8. What is Karst Topography? What forms it? What are the main characteristics?
   1. Karst Topography is unique landforms and landscapes derived by the solution of soluble rocks, particularly limestone. The main characteristics are humid climates, heavy motion of subsurface water, sinkholes, caves, and springs.

Chapter 17: Fluvial Processes and Landforms

1. What is hydrology, what is a fluvial process?
   1. Hydrology is the branch of science concerned with the properties of the earth’s water, and especially its movement in relation to land.
   2. Fluvial processes are the physical interaction of flowing water and the natural channels of rivers and streams.
2. What is a watershed/drainage divide/drainage basin?
   1. Watershed: an area of land that drains or “sheds” water into a specific waterbody.
   2. Drainage Divide: the outer boundary of a drainage basin. It represents the outside perimeter of a drainage basin and thus also the boundary between it and adjacent basins.
   3. Drainage Basin: the region that provides runoff to a stream. These are open systems that involve inputs and outputs of water, sediment, and energy.
3. What is internal drainage?
   1. Internal drainage: a process that helps to remove excess water from the ground, either naturally or using artificial systems. This drainage does not reach the ocean by surface streams; It is common in arid and semiarid regions.
4. What is stream ordering? Understand how to do it.
   1. Stream ordering: a numerical index that expresses the position of a stream channel within a hierarchy of the stream system. This ordering only changes (increases) when two streams of the same order conjoin.
      1. When two streams of a similar numerical order meet, then the larger stream that they make is given a number that is increased by one. But if two streams meet with different orders then the number doesn’t decrease.
5. What is base flow?
   1. Base flow is the portion of the streamflow that is sustained between precipitation events. It is the normal discharge of the river, and the lag time can be short or long depending on different factors.
6. Perennial vs Ephemeral streams?
   1. Perennial Streams: the water in these streams flow at least 90 percent of the time and have a well-defined channel
   2. Ephemeral Streams: streams that flow for a short time after an extreme storm and don’t stem from a well-defined channel
7. What are the sources of stream water?
   1. Streams typically derive most of their water from runoff from the form of rain and snow
   2. Groundwater discharge from the aquifers
8. Solution/suspended/saltation, what are they?
   1. Solution: some minerals are dissolved in the water and thus carried
   2. Suspended: process that moves small solids, often considerable distances, while buoyed up by turbulence in the moving air or water
   3. Saltation: the transportation by running water or wind of particles too large to be carried in suspension
      1. These are all forms of stream transportation (the movement of rock material by rivers)
9. Braided, straight, meandering rivers, what are they?
   1. Braided rivers: stream channel composed of multiple subchannels of simultaneous flow that split and rejoin and frequently shift position.
   2. Straight rivers: stream channels that flow in a relatively straight line but they only really exist for short distance along fault zones, joints, steep gradients
   3. Meandering rivers: rivers with broadly sinuous banks that curve back and forth in sweeping bends
10. Understand how a stream/river changes from its origin to its delta
    1. At the headwaters in the upper course of a river the stream flows in contact with bedrock.
    2. In the middle section of the river the stream flows over a moderate gradient and on a moderately smooth channel bed. The stream valley includes a floodplain, and it lies closer to the base level.
    3. In the lower stream course, there is a minimal gradient and proximity to base level
11. Understand the basics of river deltas and floodplains
    1. A river delta is a depositional landform constructed where a stream flows into a standing body of water (a lake or the ocean).
    2. Floodplains are areas of low-lying ground adjacent to a river, formed mainly of river sediments and subject to flooding.

Chapter 13: Earth Materials and Plate Tectonics

1. Structure of the earth’s layers – how do we know what they look like?
   1. We know what the earth’s layers look like through the uses of seismic waves that scientists generate to travel through the planet. There are two types of seismic waves that are primary waves and secondary waves. The primary waves can pass through all types of matter (liquids, solids, and gases) while secondary waves only go through solids so when they are either refracted or reflected then scientists use this reaction to know the state of the layers of the earth.
      1. Layers from inside to outside layer:
         1. Inner core (primarily composed of iron and nickel, extremely hot, densest layer, solid)
         2. Outer core (composed of molten iron that is liquified by the Earth’s heat)
         3. Mantle: (uppermost portion of the core, molten iron, composed of silicate rocks, iron, and magnesium)
         4. Aesthenosphere: (thick plastic solid layer, instigates tectonic plate movement in response to convection.
         5. Lithosphere: (the rigid, brittle layer of earth that makes up the crust and the uppermost mantle)
         6. Crust: (relatively thin, low-density surface layer of the Earth; It only represents 1% of the Earth’s density)
            1. Continental Crust: (the less dense, but thicker portion of the Earth’s crust)
            2. Oceanic Crust: (the denser, but thinner basaltic portion of the Earth’s crust)
2. What are the properties of earth’s core?
   1. The earth’s core is extremely hot, it is the innermost portion of the earth’s interior, and it is primarily composed of iron and nickel.
3. Know the density difference between the types of crusts
   1. The oceanic crust is denser than the continental crust, but it is also thinner than it. While the continental crust is less dense than the oceanic crust, it’s also thicker than it is.
4. Understand the concept of sea floor spreading.
   1. Seafloor spreading is the movement of oceanic crust in opposite directions away from the midoceanic ridges, associated with the formation of new crust at the ridges and subduction of old crust at ocean margins. This seafloor spreading at an oceanic ridge produces new oceanic crust. This spreading is evidence by how rock is older in age with distance from the ridge.
5. What is subduction? Why does it occur?
   1. Subduction is the process associated with plate tectonic theory whereby an oceanic crustal plate is forced downward into the mantle beneath a lighter continental plate when the two converge on each other. This happens because the subducting plate is denser and cooler than the overriding plate, so it slides downward.
6. What are the three rock types and how do they form?
   1. Igneous: These rocks form when molten rock matter is cooled and solidified
   2. Sedimentary: these rocks are formed by compaction and cementation of rock fragments, organic remains, or chemical precipitates
   3. Metamorphic: these rocks are formed by heat and pressure changing a pre-existing rock and they are typically harder and more compact
7. What is a tectonic plate?
   1. A tectonic plate is a large slab of solid rock that makes up part of Earth’s lithosphere and they move over the mantle and interact with each other along plate boundaries.
8. What is the difference between divergent, convergent, and transform boundaries between plates?
   1. Divergent boundaries: zones where tectonic plates are moving away from each other. They are found on both land and under the ocean. As the plates move a part magma rises and forms new crust between them that can result in ridges.
   2. Convergent boundaries: this is the area where two tectonic plates collide/converge, and they are frequently zones of subduction where deep trenches are formed.
      1. Oceanic-oceanic
      2. Oceanic-continental
      3. Continental-continental
   3. Transform boundaries: zones where two tectonic plates slide past each other and can get caught on their rock ridges and the tension causes earthquakes and ridges.
9. What is a hot spot?
   1. A hot spot is a mass of hot molten rock material at a fixed location beneath a lithospheric plate
10. Understand the rock cycle and the processes occurring.

Chapter 15: Weathering and Mass Wasting

1. What is geomorphology?
   1. Geomorphology is the study of the physical features of the surface of the earth and their relation to its geological structures.
2. What is the difference between weathering, erosion, and mass wasting?
   1. Weathering: the breakdown of rock material at and near the Earth’s surface
   2. Erosion: the process through which earthen materials are worn away and transported by natural forces such as wind or water
   3. Mass Wasting: the gravity induced downslope movement of rock material that happens without the assistance of a geomorphic agent
3. Understand the basics of slopes (friction, gravity, direction of movement)
   1. Resistant rocks stand out as cliffs and ridges and create gentle slopes and these cliffs are more prominent in arid and semiarid climates.
   2. Friction increases with the roughness and angularity of a rock fragment.
   3. Heavier objects have a greater downward pull from gravity than lighter objects and the force of gravity encourages rock, sediment, and soil to move downhill on sloping surfaces.
4. Physical, Chemical, Biological Weather – differences?
   1. Physical weathering: the mechanical disintegration of rocks that breaks larger blocks or outcrops of rock into smaller clasts
   2. Chemical weathering: decomposes rock through chemical reactions that remove ions from the original rock, forming minerals.
   3. Biological weathering: the disintegration and decomposition of rock matter accomplished in ways that are influenced by organisms, even though the processes are fundamentally physical or chemical in nature.
5. Unloading and Exfoliation, Freeze-Thaw
   1. Unloading: physical weathering process whereby removal of overlying weight leads to rock expansion and breakage, through this erosional removal of overlying weight
   2. Exfoliation: the successive removal of these outer rock sheets
   3. Freeze-Thaw: the breaking apart of rock by the expansive force of water freezing in cracks in which the water freezes, expands, and this can cause large pressures to be exerted on the walls of the cracks.
6. Carbonation, Oxidation, Hydrolysis
   1. Carbonation: carbon dioxide in water chemically combining with other substances to create new compounds and it is a common type of solution that decomposes rock material.
   2. Oxidation: this is the chemical union of oxygen atoms with other elements to create new chemical compounds.
   3. Hydrolysis: water molecules chemically recombining with other substances to form new compounds and through this reaction with rock-forming minerals to create new compounds
7. What do plants do to affect weathering?
   1. Plants can cause both physical and chemical weathering as their roots physically wedge into and expand cracks in rocks causing them to break further. They can cause chemical weathering as acids from decaying organic plant matter contributes to weathering by solution.
8. Know the four primary classes of mass movement – fall, slide, flow, creep
   1. Fall: this is a fast type of mass movement for rocks that consists of rocks plummeting downward freely through the air. Rockfalls are the most common.
   2. Slide: This is a fast type of mass movement in which rock/debris moves downslope in continuous contact with a discrete surface below and is most common in wet years.
      1. Mudslides, landslides, rockslides
   3. Flow: this is a fast type of mass movement that’s the rapid downslope movement of wet unconsolidated Earth material that experiences considerable mixing, they also consist of more churning and mixing of materials than slides.
   4. Creep: this is a slow type of mass movement that is downslope movement of soil involving the lifting and falling action of sediment particles and it slow, but persistent.
9. Human-induced mass movement – scarification
   1. Scarification is the geomorphic process that involves the erosion or weathering of a slope or cliff that results in the gradual retreat of the slope or cliff edge.