Zonal Average

zonal_cn_1.ncl: The simplest. Reads in data and then a default plot.

dim_avg: averages the right most dimension of a variable. So, for TS(time,lat,lon), the lon dimension is averaged which results in a zonal average.

This example used dim_avg_Wrap which preserves meta data.

zonal_2.ncl: A two dimensional example

zonal_3.ncl: Add zonal average to a cylindrical equidistant plot. gsnZonalMean turns on the zonal average.

The zonal average plot is modified by using gsnZonalMeanXMinF, gsnZonalMeanXMaxF, and gsnZonalMeanYRefLine to set the minimum X-axis value, the maximum X-axis value, and the X-axis value where the reference line will be drawn.

zonal_4.ncl: Transforms the axis.

tiXAxisString = "latitude", adds an axis string
tiYAxisString = "eta", adds another axis string
sfXArray= lat, uses the latitude array to label the x-axis
sfYArray=eta, uses eta to label the y-axis

zonal_5.ncl: Transforms plot so that the eta axis is evenly spaced.

gsnYAxisIrregular2Linear = True, transforms the irregular eta axis to a regular axis.

zonal_6.ncl: Changes Y-axis to log scale.

gsnYAxisIrregular2Log = True, Changes the y-axis to log scale when the original axis is irregular e.g. eta. If the y-axis is regular e.g. levels, then trYLog = True, should be used to set the y-axis to log scale.

cnInfoLabelOn = False, Turns off the contour information label.