Fields and Isolines

WHAT IS A FIELD? A FIELD IS A REGION OF SPACE THAT HAS A MEASURABLE QUANTITY AT EVERY POINT A FIELD MAP IS USED TO REPRESENT ANY QUANTITY THAT VARIES IN A REGION OF SPACE

EXAMPLES FIELD MAPS TEMPERATURE PRESSURE PRECIPITATION

ISOLINES LINES ON A MAP THAT CONNECT POINTS OF EQUAL VALUE ISOTHERMS – LINES OF EQUAL TEMPERATURE ISOBARS – LINES OF EQUAL PRESSURE CONTOUR LINES – LINES OF EQUAL ELEVATION

**ENERGY ALWAYS FLOWS FROM AN ENERGY SOURCE TO AN ENERGY SINK** ENERGY SOURCE – REGION OF THE HIGHEST ENERGY VALUE IN A FIELD ENERGY SINK – REGION OF THE LOWEST ENERGY VALUE IN A FIELD **ENERGY ALWAYS FLOWS FROM AN ENERGY SOURCE TO AN ENERGY SINK** DYNAMIC FIELD - A FIELD WHICH CAN CHANGE STATIC FIELD - A FIELD WHICH REMAINS THE SAME

HOW TO DRAW ISOLINES 1.) ISOLINES CONNECT POINTS OF EQUAL VALUE 2.) VALUES OF ONE SIDE OF AN ISOLINE ARE LOWER, WHILE ALL VALUES TO THE OTHER SIDE ARE HIGHER. 3.) ISOLINES NEVER CROSS ONE ANOTHER 4.) ISOLINES MAY FORM CLOSED LOOPS

HOW TO DRAW ISOLINES CONT’D 5.) ISOLINES NEVER END SO THEY SHOULD BE DRAWN TO THE EDGE OF THE MAP, UNLESS THEY FORM A LOOP 6.) ISOLINES TEND TO PARALLEL ONE ANOTHER 7.) ISOLINES ARE CURVED AND/OR SMOOTH WITH NO SHARP TURNS OR CORNERS.

HOW TO DRAW ISOLINES CONT’D 8.) ISOLINES ARE DRAWN ACCORDING TO A DESIGNATED ISOLINE INTERVAL. (ON A TOPOGRAPHIC MAP, THIS IS CALLED THE CONTOUR INTERVAL) 9.) ISOLINES SHOULD ALWAYS BE DRAWN IN PENCIL FIRST, TO ALLOW FOR REVISIONS

GRADIENT CHANGE IN FIELD VALUE GRADIENT = CHANGE IN DISTANCE THE RATE AT WHICH A FIELD VALUE CHANGES OVER DISTANCE CHANGE IN FIELD VALUE GRADIENT = CHANGE IN DISTANCE

DRAWING ISOLINES CLASSROOM TEMPERATURES RECORDED IN CLASS DURING THE WINTER THE TEMPERATURE INTERVAL FOR THIS MAP IS 2ºF LET’S DRAW THE LINES! FRONT

YOUR LINES SHOULD RESEMBLE THE LINES IN THE DIAGRAM BELOW!

TO CALCULATE THE GRADIENT BETWEEN POINTS A AND B 1.) FIND THE TEMP. DIFFERENCE BETWEEN THE TWO POINTS 2.) MEASURE THE DISTANCE BY MARKING THE END POINTS ON A PIECE OF PAPER AND THEN COMPARING TO THE SCALE.

PLUG THOSE NUMBERS INTO THE FORMULA GRADIENT= CHANGE IN FIELD VALUE CHANGE IN DISTANCE GRADIENT = 12ºF 16 FT GRADIENT =

NOW LABEL THE ENERGY SOURCE AND THE ENERGY SINK FOR THIS FIELD IS THIS A STATIC OR DYNAMIC FIELD?

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