• Show images such as: a school of fish with a sea lion swimming through the school capturing fish, or a humpback whale bubble netting and shooting up through a swarm of krill to emphasize that most of the productivity in the ocean occurs in the very surface layer of the ocean, and the dynamics there are important to understand.
• Show a clip of high sea state in the North Atlantic to raise interest in the investigation.
• Show or demonstrate in class the influence of mechanical wind mixing (youtube video) and encourage students to think about how mixing is most efficient in the mixed layer, since its density is uniform with depth.
• Show an animation of Chl in the N. Atl (option #1,, option #2, or an annual chlorophyll surface map of the globe, to show how productive the North Atlantic is on a seasonal basis, and pose the question, "Why is that?"

• Have the students examine a map of the data collection locations at the Irminger array. Talk through some of the special considerations about this location - latitude, proximity to Greenland, overall climate, etc. For example, something like this wind speed picture, to emphasize how unique the wind climate is at this location might be useful.
• Have the students examine stacked wind observations and solar irradiation data for the Irminger array, and in particular guide them towards recognizing the clear seasonal pattern by paying attention to the time labels on the x-axis.
• Have the students examine a stacked set of temperature time-series from different depths at the Irminger array. Emphasize to them that it is important to pay attention to, and think about, the depths at which these sensors are collected. Possible reference the mooring schematic.
• Encourage the students to turn off and on temperature time-series for different depths, to try to figure out how different combinations of wind forcing and solar forcing lead to changes in temperature at different depths.
• Students should describe how the temperature, wind and irradiance observations relate to each other.
• Is there anything they are wondering about having studied the data that they might not yet be able to explain? What more information do they want or need?

This phase of the investigation asks students to dive more deeply into the same data used in the Exploration, but with different questions.

• Have students consider whether the patterns they identify reveal something about the mixed layer dynamics throughout the season? Overall stratification of the water column?
• You could choose to have students draw a depth profile of temperature for a representative winter month and a summer month, thus practicing translating the time-series of temperature at all depths to a snap-shot of stratification at two time points. This might help students understand and interpret the data and also how to read depth profiles. Do this before revealing the feature that allows them to scroll the time series and see the accompanying depth profile in the widget.
• Encourage students to actually extract a mixed layer depth for a representative time period (weekly or monthly) and plot it as a time-series.
• Have students summarize the relationship between wind and irradiance and mixed layer depth. This could be communicated in words or in a conceptual diagram of the mixing processes. Encourage students to cite evidence from the visualization and to elaborate and clarify their understanding of the relationship.
• Encourage the students to make (i.e. draw) or verbally describe a conceptual model to a partner regarding the interaction of wind and solar irradiance and its consequences for water temperature at different depths. If possible, the instructor could then ask guiding questions and encourage them to support their model with evidence from the visualization.
  • One possible resource for visualizing complex systems is Loopy. Below is one version based on this exercise. These concept maps can be made by students or provided to students for them to play with and explore.

Application #1

• The overall idea behind this step is to encourage students to examine a wind/solar irradiance time-series from a different location (Station Papa in the North Pacific Ocean), and make predictions about temperature patterns at different depths based on what they've learned from the North Atlantic.
• Use the widget to examine and describe the relationship between wind speed and solar irradiance at this site. Discuss correlations between these variables, and in particular if there are any notable differences between the patterns here and at the Irminger Array.
• Encourage students to apply their conceptual model developed in the concept invention phase to predict temperature patterns.
• Students then turn on and off temperature time-series at different locations to test their prediction.
• You could prompt students to think about deepwater formation and thermohaline circulation as it relates to full water column mixing in winter at Irminger but not Papa.
• As an extension, you could also choose to have students discuss similar data from the Southern Ocean Array published in Ogle et al, 2018

Application #2

• In the application step students will be asked to combine insights from this activity, and background information on primary production controls (top-down, bottom-up etc.)
• Remind students for this step that the deep ocean serves as a reservoir of nutrients, and mixing can bring those nutrients into the well-lit eutrophic zone
• A short introduction/or summary of an ocean productivity conceptual model may be useful here
• Students examine a time-series of chla-concentration from the Irminger Sea, paying careful attention to when in the year productivity is high
• If nutrients data are available they could be added here
• Students then examine the time-series first introduced in the exploration segment (wind, solar irradiance and water temperature time-series, paying careful attention to seasonal patterns
• Students are then asked to integrate primary production into their conceptual model - how might primary production at this site be controlled by the physical interaction of wind and solar irradiance and their interaction with the surface of the ocean?

Possible Application #3

• The Thermohaline Circulation activity (in development by a June group) asks students to focus their attention on the winter mixing. If not yet previously discussed, students could complete that exploration at this time to more explicitly consider deep water formation.

• Have students reflect on the entirety of the case with a question like: Although we often study separately the different pieces of the ocean system, this case study nicely shows the interaction of the atmosphere (wind), and external forcing (solar energy) with water properties (temperature). As you tied together all of these pieces you learned something new about the ocean. What did you learn?
• Ask the students to consider how they learned and how much they learned and applied their learning through one or more of the following:
  • What new skills did you learn that helped you to develop a conceptual understanding of mixing in the surface ocean?
  • We focused on the implications of mixing for temperature, but what other constituents might be mixed in the surface ocean?
  • What concepts did you need to learn more about?
  • What new connections between concepts did you make?
  • In what ways did these connections help you to understand the concepts better?
  • What was the most difficult part of this activity/unit/challenge for you? Why? What helped you to figure it out?