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.
Spaghetti plots of annual sulfate concentration (a), alkalinity (b), pH (c) and total organic carbon (TOC; d) concentrations in acid-sensitive Swedish lakes. The thick black line shows the median value for observations made in a given year. Thin blue lines represent minimum and maximum values reported in a year. The thin grey lines represent individual lake time series. The red reference lines represent an alkalinity of 0 in b and a pH of 5.5 in c
