Locations that yield a spline that roughly matches Broecker's conveyor-belt path.
The data were digitized from Figure 1 of Broecker (1991), by a
multistep process. First, a world map was drawn with
oce package, using a projection (Mercator) that seemed similar
to Broecker's. Second,
locator was used to digitize points
along his conveyor-belt pathlines. No projection information being provided
by Broecker, this had to be done by coastline reference. Third, the x-y
data were converted to lon-lat space using
map2lonlat() in the
oce package. When this was done, splines were fitted to the data and
the resultant paths were drawn on the map (using code like that given in
the example). Then, some adjustments were made to the data files, to get
the splines to more faithfully represent the paths on Broecker's diagram.
Broecker, W. S., 1991. The great ocean conveyor. Oceanography, 4: 79-89.
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## Not run: library(oce) data(coastlineWorld) par(mar=rep(1,4)) mapPlot(coastlineWorld, projection="+proj=wintri +lon_0=70") data(conveyor, package="ocedata") ## Main path lon <- subset(conveyor, path==1)$longitude lat <- subset(conveyor, path==1)$latitude mapLines(lon, lat, col="blue", lwd=3) ## Secondary path (in Indian Ocean) lon <- subset(conveyor, path==2)$longitude lat <- subset(conveyor, path==2)$latitude mapLines(lon, lat, col="darkgreen", lwd=3) ## End(Not run)