OBJ: Given notes and activity sheets SWBAT construct and interpret isoline maps such as a weather map with 70% accuracy.

DN: Copy notes

ACT: Introduction to Isolines; Rules of Isolines; Interpreting Different Isolines; Isoline and Gradient video

iPad assignment

HW: Complete IAP Activity Sheet; Work on Meteorology Activity Sheet; Weather Exam, Oct 29; Interim Exam Nov 6 (10%)

What is an isoline?

• Isoline: line that connects points of equal value on a map.

• Examples:• 1) isotherm (°C): line that connects points of equal temperature.

• 2) isobar (mb, in.): line that connects points of equal air pressure.

• 3) Contour line (m, ft): line that connects points of equal elevation.

• Interval: difference between two neighboring lines.

ISOLINE PRACTICE

Watch: Constructing An Isoline Video

Rules of Isolines

• Isolines never touch or cross• Isolines are parallel and are curved• Isolines form closed loops (bullseyes) except

at the edge of the map; At center of bullseyes, H = High pressure and L = Low pressure.

• Each point on an isoline is the same• On an isoline map, the interval remains the

same

H = high pressure L= low pressure

Isobar map = part of a Weather Map

INTERVAL: _______mb

Interpreting Different Isolines

• When pressure lines are close together, strong winds; when pressure lines are far apart, gentle winds.

• When contour lines are close together, land is steep; when contour lines are far apart, land is flat, gentle.

• At an ocean shoreline, sea level is at 0 meters (0 feet).

Isobar Map (mb)STRONG WINDS

GENTLE WINDS

STEEP “cliff”

GENTLE “valley”

______feet

Finding Elevation, Distance, GradientHow do we measure elevation?

How do we measure distance?

How do we find slope or

gradient (slope) of the land?

Gradient = change in elevation

change in distance

859ft - 680 ft

2 mi

179 ft = 89.5 ft

2 mi mile

Watch: How to Calculate Gradient of a Slope