Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Correlation between outflow concentrations of NH4+ and NO2− before (black squares) and after (white triangles) the observed main regime shifts in nitrite and NH4+. The initially highly significant correlation (P < 0.001) breaks down completely after the regime shift. For a period of time before and during the regime shift, nitrite levels were at or below the detection limit; these values are not used in the regression (white circles).
