Locations that yield a spline that roughly matches Broecker's conveyor-belt path.
data(conveyor, package="ocedata")The data were digitized from Figure 1 of Broecker (1991), by a multistep
process. First, a world map was drawn with mapPlot from the oce package,
using a projection (Mercator) that seemed similar to of Broecker. 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
longitude-latitude 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.
data(conveyor, package="ocedata")
if (FALSE) {
library(oce)
data(coastlineWorld, package="oce")
par(mar=rep(1,4))
oce::mapPlot(coastlineCut(coastlineWorld,70), projection="+proj=wintri +lon_0=70")
# Main path
lon <- subset(conveyor, path==1)$longitude
lat <- subset(conveyor, path==1)$latitude
oce::mapLines(lon, lat, col="blue", lwd=3)
## Secondary path (in Indian Ocean)
lon <- subset(conveyor, path==2)$longitude
lat <- subset(conveyor, path==2)$latitude
oce::mapLines(lon, lat, col="darkgreen", lwd=3)
}