Seasonal Variability In The Mixed Layer Exploration
Your Objective
Use water temperature and atmospheric data from the North Atlantic Ocean to identify patterns and study the interaction between the atmosphere and surface ocean:
Investigate seasonal wind and solar radiation patterns in the North Atlantic
Make predictions about how surface winds and solar radiation lead to changes in mixing and temperature structure of the ocean.
Specify temperature depths to plot:
Data Tips
When the site loads, you are able to see the full dataset of wind, solar radiation and water temperature (at various depths) from the Irminger Sea Array. Specifically we are using Surface Met Data from the Surface buoy, and CTD data from Flaking Mooring B. You can interact with these data by:
Turning on and off water temperature time-series from different depths (surface, mid, deep)
Zooming in and out of the data to look at different time scales that interest you by changing the width of the highlighted section of the bottom graph (it loads with all of the data highlighted).
Hovering over data points to show data values at a specific time
Hovering over the temperature timeseries to show the corresponding depth profile plot to the right.
What is the mixed layer depth?
This is the depth of mixing in the surface ocean that results in a consistent temperature profile across upper depths of the oceans. The mixed layer depth can be identified by looking for the depth range of the surface ocean where temperature is relatively constant (above the thermocline). This constant temperature indicates mixing processes.
The MLD is determined by physical processes such as wind and water density (controlled by temperature and salinity) at this site the major driver of water density is temperature during the winter months, while a combination of salinity and temperature drive water density during the summer months. Here we note that we are viewing these mixed layer dynamics as being a fairly simple function of mechanical wind mixing and energy transfer at the surface (we ignore the impact of salinity). There are other factors, but we are keeping it simple to enhance learning.
Questions for Thought
Orientation Questions
What oceanic or atmospheric variables can you investigate in these graphs? What are their units?
Which of the variables shown here were collected in the ocean? Which were collected in the atmosphere?
What is the timeframe of the data shown?
What is the shallowest depth that water temperature data were collected? Are these surface measurements?
What is the overall range of wind speeds at this site? In the winter? In the summer? How about for solar irradiation?
Interpretation Questions
What patterns did you observe for wind and solar radiation above the surface of the ocean at this site?
When do you see these changes or patterns?
How does temperature vary over time? How does temperature vary with depth?
The mixed layer depth is the depth in the water column that is actively mixed by surface processes. Can you identify the mixed layer depth at various different points in the year using the data provided here?
What questions do you still have about what drives seasonal variability in the mixed layer?
Background Information
TBD
Dataset Information
TBD
Activity Citation: Eveleth, R., Lemkau, K., Miller, I., Smith, S., & Lichtenwalner, C. S. (2020). Seasonal Variability In The Mixed Layer. OOI Data Labs Collection.