Figure 5. (Color online) Inverse Distance Weighted (IDW) interpolation of cerium level in PMF

From

Cerium Levels in Coarse and Fine Airborne Particulate Matter in El Paso, Texas, U.S.A.

Fumador E.A., Amaya M.A., Brunner B., Clague J.W., Li W-W., Olvera H.A., Berwick M., Burchiel S.W., Pingitore N.E.

Journal of Atmospheric Pollution. 2019, 7(1), 1-13 doi:10.12691/jap-7-1-1