Indiana University Bloomington Ocean Color and Productivity Paper
Science
Instructions
Ocean Color and Productivity
The focus of this exercise is exploration of maps on the SeaWIFS website (https://oceancolor.gsfc.nasa.gov/cgi/l3) that present color-coded global maps representing ocean chlorophyll levels that serve as a measure of productivity.
The link connects to the default display of daily images for SNPP VIIRS Chlorophyll Concentration, OCI Algorithm. The target SeaWIFS data are accessed by choosing “SeaWIFS Chlorophyll Concentration, OCI Algorithm” in the second pull-down menu. There are seven data series with options for chlorophyll concentrations, which are the focus of this exercise, that represent satellite data collected over different time periods from a succession of satellites and programs. These other data sets are: Aqua Modis (July 2002-present), CZCS (Oct. 1978 – May 1986), MERIS ( Apr. 2002 – Mar. 2012), OCTS (Nov. 1996 – May 1997), SeaWIFS (Sep. 1997 – Nov. 2020), Terra MODIS (Feb. 2000 – present), and SNPP (2012 – present).
The third pull-down menu setting provides the capability to select different time periods to display, and the questions in Part A focus on the setting: “Annual composite” that provides summary maps for individual years (1997 to 2010). For the questions that follow in Part A, examine the annual composite maps of ocean productivity (https://oceancolor.gsfc.nasa.gov/cgi/l3?sen=S&per=…) for 1997 to 2010. Selection of any map in the thumbnail images will display it as a full screen image.
Select SeaWIFS Chlorophyll Concentration, OCI Algorithm in the second pull-down menu.
Select “Annual composite” in the third pull-down menu.
Enter “14” as the number of thumbnails.
Click a thumbnail to see full scale and expanded maps for that year.
Question 1 5 pts
From examination of annual composite global maps of chlorophyll concentrations identify two distinct regions within the Atlantic Ocean that represent areas of high annual productivity and low annual productivity, respectively. For your answer describe the locations (e.g. western equatorial Atlantic Ocean) of both high and low productivity regions, specifying the levels of productivity (in terms of chlorophyll a concentrations in mg/m3) observed in each.
A strong answer will designate two regions from the Atlantic Ocean, accurately describing their locations, specifying one with high and the other with low concentrations of chlorophyll a expressed as mg/m3.
Question 2 5 pts
From examination of annual composite global maps of chlorophyll concentrations identify two distinct regions within the Pacific Ocean that represent areas of high annual productivity and low annual productivity, respectively. For your answer describe the locations (e.g. central equatorial Pacific Ocean) of both high and low productivity regions, specifying the levels of productivity (in terms of chlorophyll a concentrations in mg/m3) observed in each.
A strong answer will designate two regions from the Pacific Ocean, accurately describing their locations, specifying one with high and the other with low concentrations of chlorophyll a expressed as mg/m3.
Question 3 5 pts
From examination of annual composite global maps of chlorophyll concentrations identify two distinct regions within the Indian Ocean that represent areas of high annual productivity and low annual productivity, respectively. For your answer describe the locations (e.g. equatorial Indian Ocean) of both high and low productivity regions, specifying the levels of productivity (in terms of chlorophyll a concentrations in mg/m3) observed in each.
A strong answer will designate two regions from the Indian Ocean, accurately describing their locations, specifying one with high and the other with low concentrations of chlorophyll a expressed as mg/m3.
Question 4 5 pts
From a comparison of the annual composite global maps of chlorophyll concentrations are there systematic patterns in the locations where regions of high productivity occur in the Atlantic, Pacific and Indian Oceans, and can these be attributed to specific oceanographic phenomena?
A strong answer will designate regions from different oceans accurately specifying the locations that possess high concentrations of chlorophyll a and associate these observations with discussion of the specific oceanographic factors (e.g. land run-off, upwelling, downwelling, light & nutrient availability) that result in their high productivity.
