Chemical Sensor Program
In Situ Ultraviolet Spectrophotometer (ISUS)

ISUS nitrate data is plotted as small black points over a background of data points collected at Station M1 (1 to 5 m depth) during the previous 10 years. Each of the historical data points is colored by the Day of Year on which the sample was collected.  This coloring illustrates the systematic change in the NO3/ Temp. relationship over the course of the year.     

Click on the graph to see a comparison of data collected during October through November of 2001 (which will show as a second cluster of points from 13 to 14°C) with data collected during February and March of 2002.