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Cylindrical Equidistant (CE) Projections

High Level Plot Interfaces on a CE projection

The functions below will also give you a cylindrical equidistant map plot by default, unless you set mpProjection to something other than "CylindricalEquidstant":

See the description at the top of the Map outlines examples page for information about a change to the behavior of the mpDataBaseVersion resource in NCL V6.4.0.

ce_1.ncl: A default cylindrical equidistant plot.

gsn_csm_contour_map_ce is plot interface that creates a cylindrical equidistant plot.

ce_2.ncl: Adds some intrinsic labels and manually sets the contour values.

cnLevelSelectionMode = "ManualLevels"
cnMinLevelValF = -10.
cnMaxLevelValF = 35.
cnLevelSpacingF = 5., manually sets the contour levels.

tiMainString = "CCM2 T42 July"
res@gsnCenterString = "300 mb", Creates a title and center string label

cnInfoLabelOrthogonalPosF = -0.07 Moves the contour information label into the plot. This is useful when conserving space is needed. Note in plots that contain an automatic zonal average next to the CE plot, this value was found to be -0.17.

ce_3.ncl: Colorized subregion plot with default NCL lat/lon labels.

cnFillOn = True, turns on a color plot. cnLinesOn = False, turns off the contour lines. gsnSpreadColors (available since NCL version 4.2.0.a020) is a special resource that tell the plot template to use the full range of the colormap.

In order to plot a subregion, the map must be limited. For a cylindrical equidistant projection the correct method to limit the map is by lat/lon. The plot template sets this initial resource for you. To see what other methods exist and what projections they apply to, review the mpLimitMode documentation.

You must specify the four limits of the map, however:
It is also required to set gsnAddCyclic to False whenever you plot a non-global domain.

In March of 2002, lat/lon tick mark labels were added to NCL. These look different from the ones that the plot template creates for us (see first two examples). You can choose which you prefer. Set pmTickMarkDisplayMode = "Always" to access the new default tickmarks (available since NCL version 4.2.0.a023).

ce_4.ncl: Demonstrates vectors on a CE projection. The vector example page.

gsn_csm_vector_map_ce is the plot interface that draws vectors over a map.

vcMinDistanceF = 0.017, Thins the vectors
vcRefAnnoOrthogonalPosF = -1.0, Moves the reference vector up.

ce_5.ncl: Turns off the map fill and adds a side zonal average.

gsnZonalMean turns on the side zonal mean plot. This only works for contour plots. gsnZonalMeanXMaxF and gsnZonalMeanXMinF allow the user to change the X-axis of the zonal average plot. gsnZonalMeanYRefLine sets the value that the reference line will be drawn at on the zonal average plot, the default value = 0.

cnInfoLabelOn turns off the contour info label.

The placement of the line labels is controlled by the cnLineLabelPlacementMode resource. The default is random. Also demonstrated is the "computed" value.

mpFillOn = False, turns off the gray continents.

gsn_panel is the graphical interface that creates a panel plot. More panel examples.