351
Micronutrients in the Oceans
Nitrogen (µM)
0
2
4
6
8
Surface Waters
N
O
S
A
J
J
M
A
M
F
J
D
N
O
S
A
J
J
M
A
M
F
J
D
Month
Nitrogen (µM)
0
2
4
6
8
Bottom Waters
NH 4
+
NH 4
+
NH 4
+
NH 4
+
NO 3
–
NO 3
–
NO 3
–
NO 2
–
NO 2
–
NO 3
–
Figure 8.11
Seasonal distribution of nitrogen species in the English Channel.
5
4
4.5
3.5
2.5
1.5
0.5
2000
1999
1998
1997
1996
1995
Year
Depth (m)
Nitrate + Nitrite (µmol/kg)
1994
1993
1992
1991
1990
250
200
150
100
50
0
1
3
2
Figure 8.12
The variations of NO 3
– + NO 2
– at the Bermuda Time Series station.