*/
private double advectParticle(double timeStep, Particle particle) {
int i = (int) Math.floor(particle.x);
int j = (int) Math.floor(particle.y);
CellStatus status = grid.getCell(i, j).getStatus();
double magnitude = 0;
if ( status == CellStatus.FULL || status == CellStatus.SURFACE || status == CellStatus.ISOLATED ) {
magnitude = advectWaterParticle(timeStep, particle, i, j);