Surface pressure patterns Meteorologists identify the location and geographic extent of cyclones and anticyclones by plotting sea level pressures on maps and drawing in isobars to show the pressure field. Isobars are plotted at 4mb (or 0.4kPa or 4hPa ). 3. The accompanying Figure 2 depicts surface pressure recorded over Southern Ontario in winter. a) Draw isobars at 4mb intervals on Figure 2, commencing with the 980mb line. (5 Marks) b) After placing the isobars, interpolate between lines to estimate the pressure at points C, D, and E on the map. (6 Marks) C=1003mbD=996mbE=1009mb c) Label any cyclones and anticyelones on the map with the letters "L" and "H". (3 Marks) d) Locate two "troughs" and draw a heavy dashed through them. Troughs are elongated areas of low pressure indicated by dipping isobars and pronounced "troffs". (3 Marks) e) Calculate the pressure gradient between the following pairs of points. Use the map scale given to determine the horizontal distancel( 10Marks) i) F and G : 200 kilometres on the ground correspond to 5cm on the map. Pressure gradient = change in pressure/change in distance The distance between isobars and the pressure gradient are posittvely correlated. The pressure gradient is greater the closer the isobars are spaced apart. g) Label the area with the strongest pressure gradient with an 'X'. (2 Marks) Surface pressure patterns Meteorologists identify the location and geographic extent of cyclones and anticyclones by plotting sea level pressures on maps and drawing in isobars to show the pressure field. Isobars are plotted at 4mb (or 0.4kPa or 4hPa ). 3. The accompanying Figure 2 depicts surface pressure recorded over Southern Ontario in winter. a) Draw isobars at 4mb intervals on Figure 2, commencing with the 980mb line. (5 Marks) b) After placing the isobars, interpolate between lines to estimate the pressure at points C, D, and E on the map. (6 Marks) C=1003mbD=996mbE=1009mb c) Label any cyclones and anticyelones on the map with the letters "L" and "H". (3 Marks) d) Locate two "troughs" and draw a heavy dashed through them. Troughs are elongated areas of low pressure indicated by dipping isobars and pronounced "troffs". (3 Marks) e) Calculate the pressure gradient between the following pairs of points. Use the map scale given to determine the horizontal distancel( 10Marks) i) F and G : 200 kilometres on the ground correspond to 5cm on the map. Pressure gradient = change in pressure/change in distance The distance between isobars and the pressure gradient are posittvely correlated. The pressure gradient is greater the closer the isobars are spaced apart. g) Label the area with the strongest pressure gradient with an 'X'. (2 Marks)