NOTE ->->-> DUE THURSDAY APRIL 20 TH 2006 THAT IS CORRECT I FORGOT THIS IS EASTER WEEKEND SO I HAVE EXTENDED THE DUE DATE TO THE ABOVE

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1 GEO 130 NAME OCEANOGRAPHY TEST 3 TAKE HOME TEST SPRING 2006 NOTE ->->-> DUE THURSDAY APRIL 20 TH 2006 THAT IS CORRECT I FORGOT THIS IS EASTER WEEKEND SO I HAVE EXTENDED THE DUE DATE TO THE ABOVE This test consists of: 3 case studies Bay of Bengal variation of SALINITY (AUG, SEP) (JAN, FEB, MAR) Gulf of Maine variation of primary productivity ANNUAL CYCLE Indian Ocean off the southeast coast of South Africa spring (northern hemisphere) phytoplankton bloom CHLOROPHYLL (APR, MAY, JUN) (OCT, NOV, DEC) CASE STUDY INDEX MAP 1 Map question - North Atlantic Basin 1 Map Question Antarctica and the Great Southern Ocean I eliminated questions on the films for this test. 1 of 14

2 GEO130 TEST 3 CASE STUDIES GENERAL INSTRUCTIONS Written answers must be created using a word processor, not hand written. On maps hand writing and drawing is, of course, fine. Be Neat! For scientists to communicate with each other their studies must be specific. For each of the case studies do the following: 1. Describe the geography of the region. Where is the study location and what geographic factors are relevant? What land, rivers, mountains are found in and around the region that may be important. Do not stretch the point if it is not important do not include it in the geographical summary. What ocean currents, if any, are important name them. 2. Describe the annual atmospheric and oceanic cycles which are driven by the variation of sunshine and are the starting points to discuss changes in the ocean environment. What changes take place in sunshine, the atmosphere in the region and in ocean circulation in the region that produce the changes in salinity or chlorophyll. Is the region known for a major weather system that produces drastic seasonal changes? 3. Describe the data. Indicate the time period, the data and the change in the data values. In general describe the changes from the first period to the second. For The Bay of Bengal and the Indian Ocean off South Africa, on the maps, shade in the general areas where the minimum and maximum values occur. Why do they occur there? 4. Proceed with the questions specific to each case study. 2 of 14

3 Case Study:The Gulf of Maine Map at Left Below seasonal temperature profiles Next page daily chlorophyll concentration of 14

4 The graph above shows the chlorophyll concentration in the Gulf of Maine for the year The graph on the previous page shows the annual change in the temperature profiles for four, three month periods. Write an essay (full sentences and paragraphs only) that describes what happens to the vertical temperature profile in the Gulf of Maine and why it happens over the course of a year. Include all relevant information that affect the primary productivity like vertical mixing, thermocline, pyconocline, column stability, etc. Your essay should be a concise summary of how and why vertical temperature structure changes, what is happening during each season and how if affects primary productivity. Take the information in your essay and apply it to the graph of chlorophyll concentration. Describe what is happening and why. Be sure to include the limiting factors for each season and for each change in chlorophyll concentration you discuss. 4 of 14

5 The major surface currents around Antarctica are the west wind drift (WWD - flowing to the east) and the Antarctic coastal current (ACC - also called the east wind drift). (10 points) a. Label the WWD and the ACC on the map above. b. Draw arrows indicating the net water transport for each current system based on the Coriolis effect c. The limit of the Great Southern Ocean is variable usually considered to be the Antarctic Divergence, label it on the map. d. Show where there is a zone of persistent upwelling. e. The ACC is caused by easterly (blowing to the west) surface winds. On the map illustrate the cause of the easterly surface winds around Antarctica f. The upwelling zone you located on the map above is a zone of high primary productivity but NOT all year. Why does the primary productivity decline during certain months. Which months? g. Why does the most dense water in the world form around Antarctica? What happens to it? h. IF global warming melts much of the Antarctic ice and prevents much of the north polar and Antarctic ice from forming each season what ironic occurrence may be the long term consequences of the change in the circulation of the global conveyor belt? 5 of 14

6 CASE STUDY INDIAN OCEAN OFF SOUTH AFRICA BE SURE YOU FIRST FOLLOW THE GENERAL INSTURCTIONS THEN ANSWER THE QUESTIONS BELOW. Did you indicate the areas of maximum and minimum chlorophyll? FULL SENTENCES, FULL PARAGRAPHS, USING MS WORD On the April, May and June maps draw the currents that are important in this environment. On the October, November and December map draw what the same currents look like during this time of the year. On an annual basis what are the most important oceaninc and atmospheric factors that cause the great increase in primary productivity during April, May and June? What is happening alongthe South African coast in AMJ that does not happen at other times of the year that accounts for the great primary productivity at that time? Why does this occur? This is an area where we find a western boundary current, how can there be so much primary productiviy? If you were a South African commercial fisher where would you be in April, May and June? Why? 6 of 14

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10 For the North Atlantic basin, on the map above: a. NEATLY draw all the major currents of the North Atlantic Gyre and name them. b. Indicate the western boundary current and the eastern boundary current. c. Show where upwelling occurs due to the Coriolis effect for the entire basin d. Indicate where the maximum salinity occurs. e. Show where the highest average sea level occurs. f. indicate the the trade winds. Answer the questions below (use MS Word or similar program): a. Discuss the difference between an eastern boundary current and a western boundary current and explain why the difference exists. What is the implication for primary productivity? b. What causes the large ice free area north of Norway. Be sure the currents you put on the map indicate what is going on here. c. Why is the maximum salinity where it is? d. List all the eastern and western boundary currents for the world. 10 of 14

11 CASE STUDY BAY OF BENGAL BE SURE YOU FIRST FOLLOW THE GENERAL INSTURCTIONS THEN ANSWER THE QUESTIONS BELOW. Did you indicate the areas of maximum and minimum salinity? FULL SENTENCES, FULL PARAGRAPHS, USING MS WORD Describe the pattern of salinity in Jul, Aug and Sep. Why are there so many isopleths of salinity bunched so close together in the north end of the bay? The pattern of isopleth spacing has changed on the map for Jan, Feb, Mar. Why are there fewer isolines of salinity on this map? Referencing the annual cycle that occurs in the region what is happening here that reflects the larger pattern and the annual cycle? The salinity decrease is as much as 30% to 40% from JFM to JAS for the north end of the bay but over open water farther south the salinity INCREASES 3% to 3%. Why the difference. NOTE THE UNITS ON THE CHANGE MAP ARE IN PARTS PER THOUSAND, UNLINE THE SOUTH AFRICA MAP WITH UNITS IN PERCENT. Write an essay that describes the annual cycle of atmospheric and oceanic events in this part of the world. Tell me what happens and tell me why. Be thorough. 11 of 14

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