private void addLatLon2D(CoverageCollection subsetDataset, NetcdfFileWriter writer) {
HorizCoordSys horizCoordSys = subsetDataset.getHorizCoordSys();
CoverageCoordAxis1D xAxis = horizCoordSys.getXAxis();
CoverageCoordAxis1D yAxis = horizCoordSys.getYAxis();
Dimension xDim = writer.findDimension(xAxis.getName());
Dimension yDim = writer.findDimension(yAxis.getName());
assert xDim != null : "We should've added X dimension in addDimensions().";
assert yDim != null : "We should've added Y dimension in addDimensions().";
List<Dimension> dims = Arrays.asList(yDim, xDim);
Variable latVar = writer.addVariable("lat", DataType.DOUBLE, dims);
latVar.addAttribute(new Attribute(CDM.UNITS, CDM.LAT_UNITS));
latVar.addAttribute(new Attribute(CF.STANDARD_NAME, CF.LATITUDE));
latVar.addAttribute(new Attribute(CDM.LONG_NAME, "latitude coordinate"));
latVar.addAttribute(new Attribute(_Coordinate.AxisType, AxisType.Lat.toString()));
Variable lonVar = writer.addVariable("lon", DataType.DOUBLE, dims);
lonVar.addAttribute(new Attribute(CDM.UNITS, CDM.LON_UNITS));
lonVar.addAttribute(new Attribute(CF.STANDARD_NAME, CF.LONGITUDE));
lonVar.addAttribute(new Attribute(CDM.LONG_NAME, "longitude coordinate"));
lonVar.addAttribute(new Attribute(_Coordinate.AxisType, AxisType.Lon.toString()));
}