Seasonal changes 4.
Colors are pigment concentrations, with red colors indicating highest values.
Note the variation in upwelling from month to month. Label the strongest upwelling zone on a paper map of northwest Africa. Summer conditions are on the left and winter conditions are on the right. The colorbar at the base of the images shows the temperature scale in degrees Celsius. Upwelling often has a seasonal component, as wind directions may change from one season to the next.