Table of Contents

• Dataset Description
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

This data set was collected from the Optical Plankton Counter (OPC, Focal Technologies) during Southern Ocean GLOBEC cruises LMG00104, NBP0104, LMG0203, and NBP0204. The OPC was mounted on the MOCNESS-1 frame.

The OPC data was processed into abundance spectra (N) vs. equivalent spherical diameter (ESD) of plankton in 50 size classes in the depth intervals of a correspondent MOCNESS-1 tow. The spectra calculation is based on the standard definitions in Zhou and Huntley (2007):

Definitions:

v = body volume of a zooplankter (1)
Water volume filtered (V) = OPC cross section × flow speed (2)
Abundancy sprectrum(N)= (# zooplankton in size interval delta_v)/ size interval delta_v * V (3)

Units:
ESD: mm
v: mm3
N: # mm-1 (?ESD) m-3 (water)
V: m3

Data file format:
Line 1 (header): latitude longitude date time (local, at the beginning of the deployment)
Line 2 (title): logESD dep-range1 dep-range2 ...
Line 3-52 (data): log10(ESD) log10(b) (dep 1) log10(b) (dep 2) ....

Notes:
1) Each data file represents one MOCNESS/OPC cast .The OPC failed in some MOCNESS tows.
2) The filename conventions are "CruiseName_spe_cntStationNumber.txt". The OPC cast number is same as the corresponding MOCNESS-1 cast number.
3) The depth intervals of abundance spectra are equal to the depth intervals of a corresponding MOCNESS tow.
4) The water filtered by the OPC was estimated using the flowmeter on the MOCNESS-1.
5) The size interval delta-v is evenly distributed on log(ESD) of valid OPC size range
6) The first column of the data file , represent the mid values of log10(ESD) of each size group.
7) The "-3.00" for log10(b) means 0 counts for the size group in the depth bin.
8) In some cases the OPC went through ups and downs in one depth bin, which are indicated in the depth range, for example, "25-22-75".

Reference:
Zhou, M. and M. E. Huntley, Population dynamics theory of plankton based on biomass spectra. Marine Ecology Progress Series, 157, 61-73, 1997.

The fundamental objectives of United States Global Ocean Ecosystems Dynamics (U.S. GLOBEC) Program are dependent upon the cooperation of scientists from several disciplines. Physicists, biologists, and chemists must make use of data collected during U.S. GLOBEC field programs to further our understanding of the interplay of physics, biology, and chemistry. Our objectives require quantitative analysis of interdisciplinary data sets and, therefore, data must be exchanged between researchers. To extract the full scientific value, data must be made available to the scientific community on a timely basis.

U.S. GLOBEC (GLOBal ocean ECosystems dynamics) is a research program organized by oceanographers and fisheries scientists to address the question of how global climate change may affect the abundance and production of animals in the sea.

The U.S. GLOBEC Program currently had major research efforts underway in the Georges Bank / Northwest Atlantic Region, and the Northeast Pacific (with components in the California Current and in the Coastal Gulf of Alaska). U.S. GLOBEC was a major contributor to International GLOBEC efforts in the Southern Ocean and Western Antarctic Peninsula (WAP).