PAltTICULATE ORGANIC MATTER 1N SEA WATER
15
than in the sur€ace and transition layers. Also, the quantity found in
any one area does not ordinarily vary seasonally, although certain
exceptions will be noted, so that regional comparisons are possible,
even though the amount of data available for the purpose is still fairly
small. Thus the deep water observations deserve a more thorough
analysis than was possible in the case of surface layer data.
Most of the papers cited above in connection with surface observations also included deepwater data, and a few others are included in
' + + 5 0
FIG. 2. Deepwater values for particulate organic carbon (pgilitre) in the North Atlantic
Ocean. Each number is an average of all values below 1 000 m at a station or in
some cases a group of stations in approximately the area indicated. See text for
further details and references to the original published data.
the general compilation of deepwater averages shown in Fig. 2. These
numbers were obtained by averaging all values below 200 m for a
given station or a group of stations of similar characteristics, so that
a single average is derived for a given area. This is justified on the
grounds that observed vertical variations in the North Atlantic Ocean
tend to be of an essentially random nature. The variations often exceed
the analytical error, but present sampling methods, which admittedly
have not been as closely spaced as might be desired, have shown little
indication of a systematic change with depth or maxima and minima
15
than in the sur€ace and transition layers. Also, the quantity found in
any one area does not ordinarily vary seasonally, although certain
exceptions will be noted, so that regional comparisons are possible,
even though the amount of data available for the purpose is still fairly
small. Thus the deep water observations deserve a more thorough
analysis than was possible in the case of surface layer data.
Most of the papers cited above in connection with surface observations also included deepwater data, and a few others are included in
' + + 5 0
FIG. 2. Deepwater values for particulate organic carbon (pgilitre) in the North Atlantic
Ocean. Each number is an average of all values below 1 000 m at a station or in
some cases a group of stations in approximately the area indicated. See text for
further details and references to the original published data.
the general compilation of deepwater averages shown in Fig. 2. These
numbers were obtained by averaging all values below 200 m for a
given station or a group of stations of similar characteristics, so that
a single average is derived for a given area. This is justified on the
grounds that observed vertical variations in the North Atlantic Ocean
tend to be of an essentially random nature. The variations often exceed
the analytical error, but present sampling methods, which admittedly
have not been as closely spaced as might be desired, have shown little
indication of a systematic change with depth or maxima and minima