In Activities 4 & 5, you will research how one event affected oceanographic conditions at two Gulf of Maine sites.
#4) Calculate the thermocline strength before and after an Autumn storm event.
Downland & print “Data Tracking Sheet” (PDF format). For these stations, write down the average water temperature:
ABOVE the main thermocline; and
- The first 20 meters BELOW the main thermocline:
| Station 4 | and | Station 8 |
NOTE: You’ll have sets of numbers for BEFORE the storm (red line on graph) and AFTER the storm (purple line on graph).
Note these depths under “Temp. ABOVE Thermocline” and “Temp. BELOW Thermocline.”
- Based on these calculations, classify each thermocline as follows:
- Temperature difference is less or equal to than 4 degreesCelsius: WEAK
- Temperature difference is greater than 4 degrees Celsius: STRONG
- In the shown example above, the strength of the thermocline is STRONG (14°C – 8°C = 6°C).
#5) Discover whether a storm event can change ocean layering.
Step A: Link to plots of Air Temperature, Barometric Pressure and Wind Speedduring our Autumn cruise. The dates when we were collected data at Stations 4 and 8 are shown.
- Use these data plots to discuss the storm event itself:
- How windy was it? (Note that 25 meters per second is about 50 miles per hour).
- What was the barometric pressure like during the storm?
- What happened to the AIR temperature during the storm?
Step B: Look at the following data for Stations 4 and 8 during Autumn:
- At Station 4, did the salinity profile change after the storm? What about the fluorescence profiles?
- At Station 8, did the salinity profile change after the storm? What about the fluorescence profiles?
- Did one station experience significantly more change the the other? Can you guess why or why not?
- In general, which factor (i.e., temperature, salinity or fluorescence) was most affected by the storm? Why do you think this is so?