Clim 301 HW #3

HW03: Winds (Due Sep. 24)

Part 1:

Calculate the u and v wind components for the following winds obtained from Metar reports. Calculate the components in knots and also convert to m/s:

Example:

Metar wind group: 35008KT

This wind group decodes to a wind of 350 degrees at 8 Knots. We obtain the "math" wind direction by using the provided formula in the lecture notes:

math-wind-direction = 270 - wwd = 270 - 350 = -80

Then to get the components:

u = 8 * cos(-80°) = -1.39 Knots = -0.72 m/s
v = 8 * sin(-80°) = 7.02 Knots = 3.61 m/s

Solve the following:

18017KT (180 degrees, 17 knots)
07008KT (70 degrees, 8 knots)
24037KT (240 degrees, 37 knots)
00000KT (calm)
13023KT
29003KT
36025KT

Part 2:

On the provided map of 500mb heights, calculate the geostrophic wind speed at both points A and B using the technique described in the lecture notes. Example: At point A, determine the direction of the height gradient. Along that direction, both towards higher heights and towards lower heights, and at equal small distances from point A, determine two more points. Obtain from inspection of the map the height values at those points. Estimate from the map the distance between those points (give the distance you use). Also estimate the latitude at point A from inspection of the map. Give the latitude you are using. Then perform the calculation as shown in the provided example. Show your work.

Also draw on the map at points A and B an arrow indicating the direction of the geostrophic wind. This may be done by inspection of the map (no calculations are needed). Give the direction of these two winds.

Part 3:

On the provided map of 850mb heights and temperature, draw an arrow at points A, B, C, and D showing the direction of the geostrophic wind. Indicate for each point if there is CAA or WAA at that point, based on the geostrophic winds (CAA: Cold Air Advection, WAA: Warm Air Advection). When the wind is blowing from colder towards warmer , that is CAA. When the wind is blowing from warmer towards colder , that is WAA.