Chlorophyll and phaeophytin data collected in the Southern Oceans in support of the Global Ocean Ecosystem Dynamics project, July - August 2001 (NODC Accession 0001102)

Underway meteorological data were collected during NBP01 04 to help document the surface weather conditions encountered during the cruise and to characterize the surface forcing fields in the SO GLOBEC study area during austral winter. The N.B.Palmer (NBP) arrived near the start of the large scale physical-biological survey on 27 July 2001 (YD 208) and left the area to survey the sea ice edge to the north on 26 August 2001 (YD 238). A full suite of meteorological data was collected during this 30-day period. This report provides a preliminary description of the meteorological data collected on NBP01 04 and some initial results concerning the surface forcing during winter.

The estimation of primary production has three main objectives: (1) estimation of primary productivity rates during fall and winter in the area of study as a possible source of food for krill and other zooplanktors; (2) understanding the meso-scale patterns of phytoplankton distribution with respect to physical, chemical and biological processes; (3) obtaining insight into the over-wintering dynamics of phytoplankton, including their interaction with sea ice communities. For this purpose, primary production was measured with two methods during this cruise: Photosynthesis versus Irradiance (PI) curves to estimate potential primary production and information on the dynamics of light adaptation; and finally, profiles with a Fast Repetition Rate Fluorometer (FRRF), with the aim to increase resolution in the sampling of phytoplankton activity, and the expectation of modeling primary production with this method using 14C experiments as comparison. A third approach, that of estimating daily net production with simulated in situ (SIS) experiments, was seldom performed as low irradiance levels precluded any positive carbon uptake rates. Additionally, measurements of chlorophyll and particulate carbon (POC) were taken for estimates of phytoplankton biomass, and irradiance collected from surface and profiling Photosynthetically Available Radiation (PAR) sensors.