New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Week 3 notes

by: Paige Notetaker

Week 3 notes GEOG 1111

Paige Notetaker

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

Lectures 8, 9 and 10
Intro to Physical Geography
Class Notes
25 ?




Popular in Intro to Physical Geography

Popular in Geography

This 12 page Class Notes was uploaded by Paige Notetaker on Thursday January 28, 2016. The Class Notes belongs to GEOG 1111 at University of Georgia taught by Hopkins in Fall 2015. Since its upload, it has received 18 views. For similar materials see Intro to Physical Geography in Geography at University of Georgia.


Reviews for Week 3 notes


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: 01/28/16
Geography notes- lecture 8 Air Pressure is measured as the force of the air pushing down on a     surface. In meteorology it is measured by the height of a column of     mercury and expressed in units of millibars (mb) or inches of Hg.     *  It will vary both spatially and temporally, with the average         sea-level barometric pressure being 1013 mb.     *  When displayed on a map, lines of equal barometric pressure         are called isobars.   
          *Ahigh or “heavy” pressure cell is represented by            *Alow or “light” pressure cell is represented by Pressure Gradient Force (PGF) is the difference in barometric (air)     pressure between two points. If this difference is horizontal across     the Earth’s surface, this will initiate the horizontal movement of     air or the process of advection, commonly called WIND.     Air pressure & the PGF determine wind direction & wind     strength or speed.     * Asteep pressure gradient, a strong PGF, will yield stronger (faster) winds.   * Agentle pressure gradient, a weak PGF, will yield weaker (slower) winds. WINDS will flow (blow) from an area of HIGHER pressure toward an area of LOWER pressure.     **  These differences in pressure are set-up by differences in Tº
         created by differential heating.Aportion of the Earth’s surface
         which receives more solar radiation will absorb more energy and
         heat-up. This will in turn heat-up the air above it and this warmed 
         air will rise.As the air rises, it exerts less force/pressure on the         surface and an area of Low barometric pressure is formed.
     Conversely, colder air from higher in the Troposphere will sink,
         exerting more force/pressure on the surface. This forms an area
         of High barometric pressure. 
    Also, as that sinking air reaches the surface it will spread out away         from the center of High pressure and flow toward an area of         Low pressure.
      energy imbalance --------> Tº  ---------> Pressure ----------> wind
                                         difference          difference
     Winds generated by a PGF would flow in relatively straight paths, 
     but do not because of various other forces also acting on them. 
 Coriolis Force is the apparent deflection in movement of an object     (wind, ocean currents, planes, etc.) from a straight path due to the     Earth’s rotation.  What causes this?    *  Earth is a sphere, rotates on its axis and the whole Earth’s surface         does not spin at the same velocity.Also, objects that move         independent of the Earth’s rotation will be affected by its rotation.    *  With your back to the wind (or other object), deflection is: to the right of the original path in the Northern Hemisphere to the left of the original path in the Southern Hemisphere *  Characteristics of Coriolis Force (CF):
      *  It is strongest at the poles & zero at the equator.
      * An objects speed will alter the amount of deflection with a
             higher speed yielding greater deflection.
      *  CF alters the direction, but NOT the speed of an object. TYPES OFWIND:   Geostrophic  &  Surface    Geostrophic winds (or upper-level winds) are those which flow 1 - 2 kms         above the surface. They are formed, like all winds, by Pressure         Gradient Force and affected by Coriolis Force. This yields a net effect         such that when shown on a map, geostrophic winds flow parallel to         the isobars.    Two main patterns of flow thus emerge,  Zonal and Meridional.   Zonal flow: is a pattern which exhibits a more ‘flattened’air flow with a primarily E-W orientation.     Meridional flow: exhibits a more curved flow or pattern with distinct curves, ridges and troughs, showing a more N-S orientation.    Jet Stream is a geostrophic wind pattern of particular interest and
     importance.  It is a meandering “river” of air 100-300 miles wide, 
     3000-7000' deep at an attitude between 25,000'-35,000' above sea
     Level. It has average wind speeds between 50 and 110 mph, but can
     Reach 190 mph. They are highly turbulent and their speeds and 
     location will vary considerably. Two of interest are the Polar Jet 
     Stream and the Subtropical Jet Stream. Rossby Waves are essentially a subset of the Polar Jet Stream stretching
     from one trough to another, their wavelengths on the order of 
     thousands of kilometers in length. Often a series of Rossby Waves
     circle the planet, forming a meridional pattern of ridges and troughs. Surface winds are those which flow below 1-2 kms altitude and thus     are in contact with the Earth’s surface, unlike geostrophic winds.     They are formed, like all winds, by Pressure Gradient Force and `    affected by Coriolis Force, but unlike geostrophic winds are also     affected by Friction Force with the ground. This yields a net     effect such that when shown on a map, surface winds flow across     the isobars.        The effect of all these forces on wind patterns in relation to a High     and Low pressure cell will thus be different.   Low pressure cells have Cyclonic or counterclockwise flow or circulation, in the NH (Clockwise flow in the SH)   High pressure cells haveAnticyclonic or clockwise flow/circulation in the NH (Counterclockwise flow in the SH) So remember all the aspects of how winds flow in relation to a High cell versus a Low cell: In a High Cell winds sink and diverge (flow away) from it in a clockwise circulation. In a Low Cell winds rise and converge toward it in a counterclockwise circulation. Wind Measurements   Direction is measured by compass directions, north, south, east, 
     west, NE, SW, etc.      Winds are always named for the direction they are coming from!!!!   Speed  is recorded by an anemometer in mph or kph or knots.          EX:         calm = <1mph, moderate wind = 13-18 mph,                          gale = 39-46 mph, and hurricane = >73 mph     * Winds can viewed at 3 or 4 different scales:         Macroscale             Planetary    1000 - 40,000 km     Westerlies             Synoptic     100 - 5000 km          hurricanes         Mesoscale      1 - 100 km                T-storms         Microscale     < 1 km                      tornadoes & dust devils
 *****need to know Planetary scale winds   Types of Local Winds:
     Land/Sea Breezes often form along ocean coastal areas because 
         of differential heating between the land and water surfaces, which
         forms a PGF between the two areas.An area of lower pressure         forms over the land and an area of higher pressure forms         over the water. 
    ASea Breeze is one which flows from the sea/ocean toward the land and a Land Breeze is one which flows from the land toward the sea. 
      Valley/Mountain Breezes often form in mountainous regions when
         warm air flows up the mountain during the day and cool air         flows down the mountain at night. This pattern occurs on the         same side of the mountain. Chinook wind is a warm, dry wind coming off (down) a mountain that started on the opposite side of the mountain. Known as SantaAna winds in southern California. Katabatic wind is a flow of dense cold air downslope under the
         influence of gravity in areas of large continental ice sheets such 
         as Greenland andAntarctica. GLOBALPATTERNS: PRESSURE and WIND AIR PRESSURE    Low Pressure Belts or Cells are areas of uplift and convergence at the surface and often produce unstable, severe weather.     EX:   Intertropical Convergence Zone (ITCZ),  Subpolar Lows (SPL)    High Pressure Belts or Cells are areas of subsidence & divergence at the surface and often produce stable, nice weather.     EX:   Subtropical High (STH),   Polar High (PH)   WINDS     Are dictated by:   Pressure Gradient Force,   Coriolis Force,  &   Friction Force     
         *  On a global scale a simplified 3-cell model can be identified. But the
              interaction of these cells and overall weather processes create a more 
              complex system of winds.    Know the major  pressure belts/cells:   ITCZ,  STH,  SPL,  PHP.   
         Know whether the air is rising or sinking, converging or diverging
          for each of these.   Know the major wind patterns:  Northeast and Southeast Trade Winds,         Westerlies, Easterlies.
         Know at what latitudes they will be found and which direction they flow. Geography notes- Lecture 9 ATMOSPHERIC MOISTURE:  HUMIDITY Hydrologic Cycle is the continuous movement of water from the Earth's      surface to the atmosphere and back to the surface, then to the atmosphere, ..  *  Basic cycle involves the processes of Evaporation & Transpiration         (Evapotranspiration),    Condensation,    Precipitation,     Runoff    * Transpiration refers to the water released to the atmosphere by vegetation during the process of photosynthesis.     States of Water:   solid, liquid, & gas.     Know these and the processes that 
     change water from one state to another:  melting,   evaporation,     condensation,   freezing,   sublimation,   &   deposition.
  (Know whether energy is being added (absorbed) or released for 
     each process.) 
     HUMIDITY is a measure of the amount of water vapor in the air. It can be measured in different ways or units: 
   Specific Humidity is measured as the grams of water vapor (H20v) per kilogram (kg) of air.Amass to mass measurement.
   Absolute Humidity is measured as the grams of water vapor (H20v) per cubic meter (m^3) of air.Amass to mass measurement. 
     Relative Humidity (R.H.) is a measurement of the ratio of water vapor 
         (H O ) actually in the air (water vapor content) compared 2 v         to the maximum amount of water vapor the air could hold (water
         vapor capacity). This is a function of the air temperature and is         expressed as a percentage.
     EX:  It is calculated using the specific humidity in units of g or mb.
             (actual water vapor content / water vapor capacity) x 100 = R.H.
             (10 g / 30g) x 100 = 33% RH *  Some other relevant terms:   Partial pressure refers to the idea that each component of the atmosphere         makes up a part of the total air pressure measured.  Water vapor pressure is that portion of the air pressure which is the force exerted by water vapor molecules. It is measured in millibars (mb)    Saturation is the condition when the air is holding all the water vapor it can hold. The content equals the capacity. Saturation vapor pressure is the water vapor capacity of the air as measured in mb     *  The amount of water vapor the air can hold, its capacity, is a function         of Tº. Air at a higher Tº can hold more water vapor than air at a         cooler Tº.    
   *  When the RH = 100%, the air is saturated. In this condition some of 
         the water vapor will change from a gas to a liquid, condensation occurs. 
         If enough condensation occurs, a cloud or fog will form. 
   **  This is controlled by the water vapor content &the air’s water vapor         capacity, which is controlled by Tº.
   Dew point T° (DPT) refers to the Tº at which a given mass of air becomes saturated, holding all the water vapor it can hold.Any further cooling or addition of water vapor results in active condensation, the formation of dew on a solid surface. 
     Any further cooling or addition of water vapor results in active     condensation, the formation of dew on a solid surface.
     *  It is an indication of the moisture level in the air and is controlled by 
         vapor pressure, NOT by air Tº.
     *  If the air temperature equals the DPT, then the air is saturated 
         and the RH equals 100%.
 How to change the RH:
     *  This can be done by either adding or subtracting water vapor to the mass of air OR by lowering or raising the air Tº
 Examples of how to bring air to the point of saturation (RH = 100%):
  By adding water vapor to atmosphere (air T° (capacity) held constant) air T°:                 25°C             25°C                 25°C Sp. Hum.:         5gm/kg           10gm/kg             20gm/kg capacity:          20gm/kg         20gm/kg             20gm/kg R.H.:                 25%                 50%                 100%                  {(5/20)X100}    By cooling the air (actual water vapor content (Sp. Hum.) constant) air T°:                 30°C             20°C                 15°C Sp. Hum.:         10gm/kg         10gm/kg             10gm/kg capacity:            27gm/kg         14gm/kg             10gm/kg R.H.:                 37%                 71%                 100%                  {(10/27)X100}   **  When the R.H. varies during the day it’s because of a change in air T° OR a change in the amount of water vapor in the air.   *  The most common & easiest way for the RH of the air to be changed is by changing the air T°        *  This is also the most common & easiest way for the air to become         saturated and thus for condensation to occur, by changing the air T°.  **  Water vapor content in the air and thus RH varies from day to day,         month to month, seasonally and spatial (from place to place).        *  Remember, the colder the air, the less water vapor is can hold. While the warmer the air, the more water vapor it can hold. Geography notes- lecture 10 ADIABATIC PROCESSES  In meteorology the term adiabatic refers to a parcel of air changing temperature without heat energy being added or removed. ** Aparcel of air that contains warm air is less dense (lighter) and
         thus may rise.As this parcel of air rises in the atmosphere, it will
         encounter lower pressure and thus expand.As it expands the
         molecules in it will start to slow down and thus kinetic energy         levels will decrease.As this occurs, the T° will also decrease.
 **  Conversely, a parcel of cold air is more dense (heavier) and thus
         sinks.As this parcel of air sinks in the atmosphere, it will
         encounter higher pressure and thus be compressed.As it is
         compressed the molecules in it will start to speed up and thus 
         kinetic energy levels will increase.As this occurs, the T° will         also increase.
  SO,   Expanding air = T° decrease Compressing air = T° increases 
 **   BUT, the T° changes WITHOUT heat being added or subtracted *** This is Adiabatic Temperature Change. Changing the Tº of the
         air without adding or subtracting heat. Simply the result of 
         compressing the air or allowing it to expand.
   RESULT:       **Rising air in the atmosphere expands and cools.     ** Sinking air in the atmosphere is compressed and warms.     The Rate ofAdiabatic Temperature Change varies with the humidity     condition (water vapor content) of the air, is it Dry (unsaturated) or     Wet (saturated). Unsaturated air will change T° at a faster rate than      will saturated air.   DryAdiabatic Rate:    (DAR or DALR)     When a parcel of air is unsaturated its air Tº > dew point Tº and         thus its RH < 100%.       *   The DAR of unsaturated air is a constant rate of               1ºC / 100 m   or   10ºC / 1000m.         Thus:  rising air cools at 1°C/100m (10°C/1000m) and sinking air warms at 1°C/100 m (10°C/1000m).   SaturatedAdiabatic Rate:    (SAR or SALR)
     When the air parcel is saturated its air Tº  =  d.p.Tº and thus its         RH = 100%.
   *  The SAR is not a constant rate but a variable rate of 
    .5° - .9°C/ 100m or 5° - 9°C/ 1000 m
     *   The SAR is dependent on the moisture content of the air. The more water 
           vapor there is in the air, the slower the rate of decline
             (closer to 5°C / 1000m). 
     *   This is because condensation releases latent heat, thus slowing
             the rate of cooling (or warming).
   **  So as warm air rises (the process of convection) it cools. If the air T°         reaches the dew point T°, saturation is reached and thus condensation         may begin. If there is enough water vapor in the air parcel, then a         cloud may form. The level of the atmosphere where this occurs is         known as the condensation level and will vary temporally and         spatially.     Condensation level is the height in the atmosphere at which condensation occurs, where cloud formation begins (usually seen at the bottom of a cloud mass). RH = 100%;    air Tº = d.p.Tº    Atmospheric  Stability refers to the tendency of an air parcel with its water vapor, to either remain in place or to change vertical position by ascending (rising) or descending (falling).        * Astable parcel of air resists vertical displacement or, when
             disturbed, tends to return to its starting place.
        * An unstable parcel of air continues to rise until it reaches an
             altitude where the surrounding air has a density & T° similar
             to its own.
 Rules of Stability    1)   When an air parcel is warmer (less dense) than the surrounding             air, the parcel will rise:    UNSTABLE  air or condition.    2)   When an air parcel is colder (denser) than the surrounding air,             it will tend to stay at the same level  or  sink:    STABLE air.    3)   The Environmental Lapse Rate (ELR)  is the Tº profile of the             atmosphere (surrounding air).  The actual T° lapse rate in the lower             atmosphere at any particular time under local weather conditions is             the ELR.      Whether a particular parcel of air will rise (unstable) or not rise (stable)         is a function of the T° inside the parcel of air as compared to the T°         outside the parcel of air, and thus the ELR determines air stability         or instability.   Types of Stability    Stable conditions exist when the  ELR < DAR.         Absolutely stable conditions or Absolute Stability     *   This usually results in NO UPLIFT of air, and may bring about             subsidence or sinking of the air parcel. This usually causes clear sky conditions. High pressure cells form stable atmospheric conditions     *   The most severe example of stable conditions is a Tº inversion             when the air Tº is increasing with increasing altitude in the             troposphere.    Unstable conditions exist when the  ELR  >  DAR.              Absolutely unstable conditions or Absolute Instability     *  This usually results in UPLIFT of the air parcel and often leads to cloudy sky conditions. Low pressure cells form unstable atmospheric conditions.        Conditionally Unstable conditions exist when the ELR is between     the DAR & the SAR.     SAR  <  ELR  <  DAR     *   The atmosphere will vary between Stable and Unstable and usually the atmosphere is more Unstable in the upper portion and more Stable in the lower portion.   ***   Stability is important in daily weather patterns because it controls             whether clouds form or not and the type of clouds that may form.             This in turn will affect the potential for precipitation.  LIFTING MECHANISMS    *   For air masses or parcels of air to cool adiabatically ( by expansion) and         to reach the dew-point T° and saturate, condense, and form clouds and 
         perhaps precipitation, they must lift and rise in altitude.    *   There are 4 principal lifting mechanisms which operate in the atmosphere.            Convective Lifting,    Convergent Lifting,
             Orographic Lifting,    Frontal Wedging 
    Convective Lifting is the process of warming a parcel of air at the surface by conduction, then the whole parcel rising into the atmosphere since it is warmer than the surrounding air.     *   The heating of the Earth’s surface at a given location will produce the             necessary elements to establish these UNSTABLE conditions.     *   If there is enough moisture in the air parcel, then cloud formation may             develop &  even precipitation. This is commonly how afternoon thunderstorms are produced in the summertime.     *   This is also part of the process, in conjunction with convergence,             that occurs in Low pressure cells. Convergent Lifting is the process by which winds flow together from opposite directions & are forced to rise due to compression or ‘squeezing’   *  Both convection & convergence are at work to form the         Inter-Tropical Convergence Zone (ITCZ), and Low pressure cells. Orographic Lifting is the process by which air is focused to rise over a mountain range, or other elevated land barrier, and thus cool adiabatically.       *  The pattern of precipitation is governed by this as rain/snow will
         occur on the windward side of the mountain, while little or no
         precipitation occurs on the leeward side.
     *  This often forms a Rain Shadow Desert on the leeward side.
  Frontal Wedging (Lifting) is the process by which cold, dense air acts similarly to a mountain barrier forcing warmer, less dense air to rise over it.       *  The leading edge of a mass of cold air is known as a cold front &
         similarly the leading edge of a mass of warm air is known as a
         warm front. So this mechanism is associated with cold/warm fronts
         &  Mid-Latitude Wave Cyclones (frontal systems).
    *  This usually produces clouds & precipitation with often severe
         storms or thunderstorms along the cold front.


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


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'

Why people love StudySoup

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

Jennifer McGill UCSF Med School

"Selling my MCAT study guides and notes has been a great source of side revenue while I'm in school. Some months I'm making over $500! Plus, it makes me happy knowing that I'm helping future med students with their MCAT."

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

Parker Thompson 500 Startups

"It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.