Class Notes (836,367)
Canada (509,757)
Geography (83)
GEOG 205 (55)

GEOG 205 - Weather and Climate.docx

7 Pages
Unlock Document

GEOG 205
John Yackel

Weather and Climate GEOG 205 – January 29, 2014 Weather – state of the atmosphere with respect to heat and cold, wetness or dryness, calm or storm, clearness of cloudiness. Climate – the average course or condition of the weather at a place usually over a period of years as exhibited by temperature, wind velocity, and precipitation It is a matter of temporal scale! Due to the time scale and aggregation an individual cannot experience climate! (Time scale – 30 years) Earth’s Temperature depends on: 1. The amount of solar radiation received 2. The amount of solar radiation reflected 3. The amount of solar radiation trapped a. Ocean traps a lot of solar radiation Sunspots - Magnetic storms – releases electromagnetic radiation - Produces flares - Occur on 11 year cycles - Low sunspots numbers have been linked to cold periods (e.g. LIA) - Cycle corresponds to a 0.1% variation in energy output Seasonality - Here in Calgary, there are 3 components of seasonality that we can factor in: o Earth rotates once every 24 hours on an axis, at a tilt of 23*, and that tilt at different times of the year affects our seasons o Orbit around the sun is an ellipse, so at the perihelion (January 3 it’s at its closest) it is closer to the sun, at the aphelion (July 3 it’s at its furthest) it is further away from the o Line of Solstice goes across the orbit (June 21 and December 21) o Equinox goes perpendicular to Line of Solstice (March 21 and September 23) - Seasonality is more pronounced the further you get away from the equator Global Seasonal temperatures (The 4 Main Factors of Temperature) - Latitude (further away from the equator, more pronounced seasonal changes) - Altitude - Cloud cover - Distance from major water body o Oceans and large water bodies hold a lot of heat, so being located next to a body of water can increase the temperature of a location 4 Layers of Atmosphere Troposphere – narrow, little more than 10 km thick, bottom, oxygen rich but chaotic (storms) Stratosphere – air is stable, very dry, virtually no weather, home to ozone layer (filters radiation from space) ~ 50,000 feet Mesosphere – protects us from meteors, home to noctoluscent clouds (thin, wispy clouds usually seen at sunset) Thermosphere – 84km above Earth, considered to be the beginnings of space – where the ISS is – creates the Aurora Volume of the atmosphere is just 5% of the earth. GEOG 205 – January 31, 2014 Milankovitch Cycles - Eccentricity (~100,000 year cycles) - Axial Tilt (~41,000 year cycles) o Halfway through the cycle, the earth changes the axis it rotates on by about three degrees - Precession (~23,000 year cycles) o Earth wobbles like a top throughout the 23,000 year cycle o Axial tilt is what actually changes – still 23.5* Paleoclimate – fancy word for ‘past climate’ Isotope analysis of the ice cores shows what the atmosphere was like when that ice formed. - Did the temperature go up and cause all of these atmospheric changes, or did the atmospheric changes cause a rise in temperature? Bit of a debate. Albedo - The % of solar radiation reflected back - Earth’s average is about 30% - - Albedo of 0.05 = a 5% albedo, 0.40 = 40% - Cutting down the Amazon rainforest means there will be fewer green trees to absorb solar radiation, so more will be reflected, essentially cooling the earth - Why should we care about sea ice? o Ice and snow have a high albedo, and it moderates the warming of the atmosphere with that high percentage of reflection o Water has a low albedo, so it absorbs more radiation, and so it warms the ocean and atmosphere o The loss of ice changes the temperature and salinity which drives ocean currents. GEOG 205 – February 3, 2014 Albedo continued - Many European cities at same or similar latitudes as some N. American latitudes will have warmer overall temperatures because of the hot/warmer air that is blown off the ocean and onto the continent - Lack of sea ice (due to melting) would mean a political dispute over the territory – makes a big difference with the trade path and trade routes Why are the greatest seasonal temperature ranges on land? - Only the surface of
More Less

Related notes for GEOG 205

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.