Geography 1111 Lecture 3 & 4 Notes 8-17
Geography 1111 Lecture 3 & 4 Notes 8-17 GEOG 1111
Popular in Intro to Physical Geography
Popular in Geography
This 7 page Class Notes was uploaded by Bridget Notetaker on Monday August 22, 2016. The Class Notes belongs to GEOG 1111 at University of Georgia taught by Hopkins in Fall 2016. Since its upload, it has received 74 views. For similar materials see Intro to Physical Geography in Geography at University of Georgia.
Reviews for Geography 1111 Lecture 3 & 4 Notes 8-17
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 08/22/16
Geography 1111 Lecture 3 Notes Earth and Sun Relationships o Greater than (>) 99% of Earth’s energy is from the sun o The amount (intensity) of sunlight striking the Earth varies: Spatially: over space or area with latitude Temporally: over time with the seasons (day length) and between day and night These variations cause an unequal heating of the Earth’s surface with derives the ocean currents and forms wind In turn, energy is transported across the globe Earth Movements: o Rotation: the spinning of the Earth on its axis It makes one turn about every 24 hours defining day & night Meaning the same side of the planet is not always facing the sun making solar intensity vary The Earth turns counterclockwise when viewed above the North Pole and the atmosphere rotates with the Earth o held by force of gravity A circle of illumination forms between the area of light (daytime) and dark (nighttime). o Revolution: movement of the Earth in its orbit around the Sun It makes one orbit every 365.2422 days (365 days, 5.8 hrs.) Commonly called 1 calendar year It is a counterclockwise orbit, when viewed above the North Pole o The orbit is elliptical, so at one time of the year it is closer to the Sun than the opposite end of the orbit and solar intensity varies o These 2 points are known as: 1. Perihelion: when the Earth and Sun are closest to each other About 1.47 X 108 km or 91,500,000 miles apart, which occurs on January 4 o Thus a little higher solar intensity 2. Aphelion: when the Earth and Sun are the furthest apart About 1.52 X 108 km or 94,500,000 miles apart), which occurs on July 4 o Thus a little lower solar intensity Earth’s Seasons: o Seasons are due to Earth’s orientation to the Sun and thus the varying angle the Sun’s rays strike the Earth’s surface o Why they occur: Revolution Rotation Tilt of the Earth on its Axis Axial Parallelism Sphericity o Inclination of the axis: Earth’s orientation to the Sun as a result of the tilt on it’s axis Currently 23.5° from a perpendicular to the plane of the elliptic Its revolution around the Sun and its daily rotation on its axis are also major factors o Axial Parallelism: the orientation of the North Pole of the Earth toward a specific star The fact that the Earth is a sphere (its sphericity) are also factors controlling solar intensity at the surface o Inclination of the axis, axial parallelism, and the shape of the Earth’s orbit (revolution) change over long periods of time This can be seen by the varying solar intensity with day length and with varying seasons Summer has: o Longer days o Higher solar altitude o More intense sunlight and more energy Winter has: o Shorter days o Lower solar altitude o Less intense sunlight and less energy o Solar Altitude (SA): the angle of the Sun above the horizon at any given latitude Ex: At a SA of 90°, the sun is “directly overhead”, and yields the potentially maximum solar intensity Solstices and Equinoxes o The 5 factors above (Revolution, Rotation, etc.…) cause the seasons with 4 days of particular interest: The 2 Solstices and the 2 Equinoxes March Equinox o Start of Spring in Northern Hemisphere o Start of Fall in Southern Hemisphere June Solstice o Start of Summer in Northern Hemisphere o Start of Winter in Southern Hemisphere September Equinox o Start of Fall in Northern Hemisphere o Start of Spring in Southern Hemisphere December Solstice o Start of Winter in Northern Hemisphere o Start of Summer in Southern Hemisphere o The Sun is never directly overhead (SA = 90°) outside 23.5° North or South Latitude (the Tropic of Cancer and Capricorn) o Northern Hemisphere Winter = Southern Hemisphere, etc. Climatological Seasons: o Winter: Dec, Jan, and Feb o Spring: Mar, Apr, and May o Summer: Jun, Jul, and Aug o Fall: Sep, Oct, and Nov Geography 1111 Lecture 4 Notes Weather Climate The day-to-day conditions of the The statistical properties of the Atmosphere atmosphere, including measures of the average conditions, variability, etc. over long periods of time Constantly changing Slow, long-term changes The state or condition of the A description of aggregate atmosphere at a particular time weather conditions and place Comprised of various factors: A sum of the daily and seasonal Air pressure weather events over decades, hundreds or thousands of years Air temperature Humidity Averages of these factors Clouds Precipitation Wind Visibility, etc. Meteorology: the science that studies the atmosphere and its processes on a short-term basis Climatology: the study of long-term atmospheric conditions Origin of the Atmosphere: A B C D --|------------------------------------|------------------------------|--------------- ----- 4.5 billion 3 - 1.5 bybp .5 bybp years before present (bybp) A. Earth formed and hot gases escape The process of outgassing B. Earth cooled and gases accumulate The atmosphere comprised mainly of: o CO2 (Carbon Dioxide) o N2 (Nitrogen) o Methane There was little to no O2 (oxygen) or O3 (ozone) C. O2 generating aquatic organisms evolve and oxygen supply slowly rises The main process for increased oxygen levels is photosynthesis D. Green land plants widespread and the atmosphere has taken on its basic present conditions Ozone levels increase and spread Composition of the Atmosphere: o The atmosphere is a mixture of discrete gases, with solid & liquid particles suspended within it o Some components are fairly stable while others vary spatially and/or temporally o Constant Gases: those found in the same proportions (%) within the lower atmosphere (up to 50 miles altitude) 3 gases makeup just under 100% of the atmosphere Nitrogen (N): ~78% Oxygen (O): ~21% Argon (Ar): ~9% o Variable Gases: those present in the differing amounts spatially and/or temporally within the lower atmosphere 4 gases influence weather and life systems Carbon Dioxide (CO2) Ozone (O3) Water vapor (H2O) Methane (CH4) o CO2 and CH4 are two of the Greenhouse Gases which help absorb and reflect long wave or terrestrial radiation (heat energy) emitted by the Earth which helps regulate surface temperatures o Water vapor (also a Greenhouse Gas) is quite variable throughout the atmosphere Ranges from about 4% by volume in tropical areas to <1% in some deserts It is the source material for cloud formation and precipitation It also absorbs radiant energy and helps regulate surface temperatures and is important in energy transfer within the atmosphere Water is the only substance found in all 3 states (solid, liquid and gas) o Carbon Dioxide, methane, water vapor and nitric oxides are all known as the “Greenhouse Gases” Ozone: concentrated in the Stratosphere (10-50km above the surface) in amounts of <.00005% by volume of the atmosphere o It is not a Greenhouse Gas but it does absorb damaging ultraviolet (UV) radiation coming from the Sun o It is important because it helps block out some of the UV radiation (harmful to living organisms) and helps regulate surface temperatures o Ozone Hole: around the Earth’s Polar regions and is a seasonal depletion of ozone in the stratosphere Thought to be caused by increased amounts of chlorofluorocarbons (CFC’s) in the stratosphere because the chlorine atom of the CFC molecule has been shown to break apart ozone molecules Some research suggests that a 1% loss of O3 leads to a 2% increase in UV radiation reaching the Earth’s surface Some consequences of less ozone: o Increased amounts of UV radiation reach the Earth’s surface which can lead to: Increased cases of human skin cancer and cataracts Increased damage to other animals and to plants Increased energy reaching the Earth’s surface and this increased surface temperatures Vertical Structure of the Atmosphere: o Important aspects of the atmosphere: Air pressure: At sea level the average pressure is 1013mb or 1kg above every cm2 or 29.92in of mercury Air pressure increases with decreasing height Regarding volume, 50% of the atmosphere is below 5.6km (~3.36mi) and 90% of the atmosphere is below 16km (~9.6mi) Temperature: Measure of the degree of hotness or coldness of a substance o Temperature may increase or decrease with changing altitude in the atmosphere o In the troposphere it normally decreases with an increase in altitude at an average rate of 6.5°C/km, but as the temperature increases with altitude its called a temperature inversion o Any change in temperature with a change in altitude is termed a Temperature Lapse Rate Layers of the Atmosphere: o Two general regions based on their chemical composition 1. Homosphere: the area of uniform chemical composition in the lower atmosphere Surface to 80-100 km (50-63mi) altitude 2. Heterosphere: the area of non-uniform chemical composition in the upper atmosphere (above the Homosphere) o There are also 4 layers delineated by temperature changes: 1. Troposphere: where temperature usually decreases with increasing altitude from the surface to an average altitude of 8-10mi o This is where almost all weather takes place 2. Stratosphere: where temperature stays constant or increases with altitude o It lies above the troposphere to an altitude of about 50km (31mi) and contains the ozone layer which is the heating element for this layer 3. Mesosphere: shows a temperature decrease with increasing altitude between ~50-80km (31-50mi) 4. Thermosphere: the top layer and where the temperature increases dramatically with altitude o The area of the atmosphere where the aurora borealis and aurora australis occur (Northern and Southern Lights)
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'