Weather & Climate
Lab 1B - 1E
Lab 1B: Earth Measures
Lab 1B: Earth Measures
Latitude
Longitude
Lab 1B: Earth Measures
• Earth’s circumference = 360°
• Quarter of a sphere = 90°
0° Latitude = Equator
Expressed in degrees North or South
0° Longitude = Prime Meridian
Expressed in degrees East or West
Lab 1B: Earth Measures
• Important lines of Latitude:
66 ½° N = Arctic Circle
23 ½° N = Tropic of Cancer
23 ½° S = Tropic of
Capricorn
66 ½° S = Antarctic Circle
Why ½
degrees?
Lab 1B: Earth Measures
• Latitude & Longitude are broken down:
• 1° = 60’ (One Degree = 60 Minutes)
• 1’ = 60” (One Minute = 60 Seconds)
• Note: This is NOT how Time is broken down. Time
zones are not directly related to the seconds and
minutes in Latitude and Longitude
Lab 1C: Location
• Globes often mark parallels & meridians in
10° or 15° increments
Longitude = MERIDIANS
•Converge at the poles
•Farthest apart at
equator
•Range from 0° to
180°
Latitude = PARALLELS
Range from 0° to 90°N and
90°S
Lab 1C: Location
Key Words:
• Parallels – relate to latitude
• Meridians – relate to longitude
• Prime Meridian – GMT longitude
• IDL (International Date Line) – 180 degrees
longitude
Lab 1C: Location
• Written as Degrees Minutes Seconds
ex: 43°52’44”N, 103°27’35”W
• Always written as Latitude, Longitude
Lab 1D: Time
• Earth rotates from West to East
• Hence, the sun rises in the east, and sets in
the west
• If time is newer in the west, and older in the
east, then it must be later in the day in the
eastern portion of the globe
Lab 1D: Time
8:00
7:00
9:00
Note: physical features alter the rigidity of time zones
10:00
Lab 1D: Time
• One day is 24 hours, this is the same amount
of time it takes for the earth to complete one
rotation
• If the earth consists of 360°, and it takes 24
hours to rotate, how many degrees does one
hour occupy? 15°
• 360°/24 hours = 15°
Lab 1D: Time
Lab 1D: Time
• There are 24 standard time zones
– Marked by degrees of longitude
– Based on central meridians spaced 15° of
longitude apart
• Moving east to west:
– Time becomes earlier
• Moving west to east:
– Time becomes later
Lab 1D: Time
• Greenwich Mean Time (GMT)
– Established in 1884 as world reference for
standard time
– Also known as Universal Time Coordinated (UTC)
– Sometimes referred to as Zulu, which is
represented as a 24:00 clock
Lab 1D: Time
• A difference in time can be calculated
mathematically
2 Steps:
1.Find the difference in degrees, between the
two time zones
2.Divide that number by the degrees the earth
rotates an hour (15 degrees)
Lab 1C: Time
Tokyo: 135°E
Rome: 15°E
Difference = 120°
120°/15° = 8
Hours
Tokyo is 8 hours later than Rome, because it is
east of rome
Tokyo: 135°E
Rome: 15°E
Rome
15°E
30°
E
45°
E
60°
E
75°
E
90°E
REMEMBER: 15° of longitude = 1 hour
East = time gets later (+)
105°
E
120°
E
Tokyo
135°E
Lab 1D: Time
International Date Line
– Generally follows the 180° meridian
– Traveling from east to west = next day
– Traveling from west to east = previous day
Lab 1D: Time
• Daylight-saving time:
– Summer = longer days (DST)
– Winter = shorter days (ST)
• In U.S., not Hawaii or most of AZ
• Countries near the equator do not observe day-light
savings.
• “Spring Ahead, Fall Back”
Lab 1D: Time
• Sunrise & Sunset Time Correction:
– East of our location = earlier
– West of our location = later
• 1° Longitude = 4 Minutes
• 60 Minutes (in an hour) / 15° (degrees rotated in
an hour) = 4 Minutes
Lab 1E: Isolines
• Isolines: lines on a map that connect points of
equal value
• Often used to show varying levels or
concentrations:
•
•
•
•
Rainfall
Temperature (Isotherms)
Elevation
Pressure (Isobars)
Lab 1E: Isolines
• Isolines never cross
• Topographic Maps
consist of contour
lines showing
elevation
Lab 1E: Isolines
•
•
•
•
Drawn at regular intervals
Always closed lines
Never cross each other
Gradient represented by distance between lines:
• Close together = rapid horizontal change
• Far apart = gradual horizontal change
• Values inside a closed isoline are either higher or
lower than those outside the closed isoline.
Lab 1E: Isolines
Must label
your
isolines!
10°
15°
Next Week:
• Prepare for Pre Lab Quiz, Lab #2 given at the
beginning of class
• Hand in ALL of Pre-Lab #1, Sections 1A-1E