Southern Ocean
JGOFS Southern Ocean Data from the Ross Sea

Ross Sea Bloom Cycle

Modis Chl a January 2007

Ross Sea Station #5
Southern Ocean Station 5 Data Collected Jan 17, 1997 AESOPS NBP97-1, Ross Sea Process Cruise II
Download CTD data for the Arabian Sea from the class website: here>
Instructions can be found at the Station 13 placemark

Ross Sea Station #11
1. Calculate the total amount of chlorophyll in the water column (mg/m2) at all three stations using the in situ chlorophyll measurements and mixed layer depths that you estimate.
2. Total chlorophyll in the mixed layer one week ago at this location was measured at 13.5 mg Chl/m2. What is the chlorophyll increase per day at this station?
3. Using a laboratory determined carbon to chlorophyll ratio of 80 ug C: ug Chl, calculate the rate of primary production at this station in mg C per day.
4. Carbon to chlorophyll ratios very substantially between phytoplankton species. A common, non-siliceous phytoplankton species regularly exhibits a ratio of 150 ug C: ug Chl.
Show how much dominance by one species or another can affect carbon-based productivity calculations by recalculating primary production using the new ratio.

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) Jan 1, 2007 00:00-Feb 1, 2007 00:00

NASA Earth Observations

Colorbar

Modis Chl a Feb 2007

Ross Sea Station #25
1. Compare all three stations in terms of the nutrient drawdown characteristics, mixed layer depths, and chlorophyll biomass. When presenting this data, make sure to note the average nutrient concentrations in the mixed layer and at depth.
2. Calculate the ratio of nitrate to phosphate and nitrate to silicate in the water column. Present an average mixed layer N:P and N:SI ratio and an average deep N:P and N:Si ratio at each station.
Explain why the surface and deep ratios may not be the same. Is there is variation between stations in the surface ratios? If so, why? Is there variation at depth?
3. Describe the nitrogen dynamics at one of your stations, preferably one with ammonium or urea measurements.
Can you tell what source of nitrogen is preferred by phytoplankton? Do you see a subsurface nitrite maximum? If so, how does it correspond with the oxygen profile? For your presentation make sure to note what components of the nitrogen cycle might be operating at this location.
4. From observation of the satellite chlorophyll time-series and your knowledge of the latitude and season, what is the state of the phytoplankton bloom at this station?
Postulate what factors might contribute to a decline in productivity in this region.

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) Feb 1, 2007 00:00-Mar 1, 2007 00:00

Modis Chl a March 2007

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) Mar 1, 2007 00:00-Apr 1, 2007 00:00

Modis Chl a April 2007

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) Apr 1, 2007 00:00-May 1, 2007 00:00

Modis Chl a May 2006

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) May 1, 2006 00:00-Jun 1, 2006 00:00

Modis Chl a June 2006

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) Jul 1, 2006 00:00-Aug 1, 2006 00:00

Modis Chl a July 2006

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) Jun 1, 2006 00:00-Jul 1, 2006 00:00

Modis Chl a August 2006

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) Aug 1, 2006 00:00-Sep 1, 2006 00:00

Modis Chl a September 2006

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) Sep 1, 2006 00:00-Oct 1, 2006 00:00

Modis Chl a Oct 2006

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) Oct 1, 2006 00:00-Nov 1, 2006 00:00

Modis Chl a Nov 2006

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) Nov 1, 2006 00:00-Dec 1, 2006 00:00

Modis Chl a December 2006

NEO Chlorophyll Concentration (1 month - Aqua/MODIS) Dec 1, 2006 00:00-Jan 1, 2007 00:00