Lab 12 – Wildfires

Forest Fire Introduction:
At some point in our lives, many of us have had the experience of sitting around a campfire. Occasionally, the smoke was blown into our face. What are some of the characteristics of this smoke plume? Recall the dry heat and the ash that perhaps made you cough a bit. These same characteristics of smoke are present in wildfire smoke.

Figure 12.0.1

A group of people sitting around a campfire at night

The much larger smoke plumes produced by wildfires drift over streams, lakes, and occasionally, the open ocean. In this lab, we are going to look at the impacts of smoke plumes over the ocean, as they produce observable physical, chemical, and biological changes.

2020 Oregon Labor Day Fire:

In September 2020, a wildfire outbreak spread quickly across western Oregon causing significant damage and shrouding the region in smoke for more than a week. Smoke from these fires, driven by an easterly wind event, could be seen from satellites (see Figure 12.0.2). The smoky air was measured by the Coastal Endurance Array’s Oregon Shelf Surface Mooring (CE02SHSM) 10 nautical miles west of Newport, Oregon, which measured the lowest relative humidity values (<18%) since it was first deployed in April 2015. These winds and the associated smoke plume were followed by a week of reduced sunlight. Six meters below the surface, sunlight was reduced by the red smoke. Closer to shore at the Oregon Inshore site (CE01ISSP), light levels were measured throughout the water column by an OOI coastal surface piercing profiler. The smoky air had relatively high concentrations of carbon dioxide and other ocean nutrients capable of producing an algal bloom. The satellite image below shows the smoke plume over the Endurance Array in Coastal Washington and Oregon on September 9, 2020. In the image, at the extreme eastern edge of the smoke plumes, in the region of the red circle. is the location of the wildfires. Figure 12.0.2 [caption id="attachment_14508" align="alignnone" width="592"]This is an image of the Oregon coastline where the fires occurred, showing the ash cloud over the ocean and identifying the location of the fires. The satellite image above shows the smoke plume over the Endurance Array in Coastal Washington and Oregon on September 9, 2020. In the image, at the extreme eastern edge of the smoke plumes, in the region of the red circle. is the location of the wildfires.[/caption]

Learning Outcomes

  • LO1. Understand the connection between climate change and wildfires.
  • LO2. Investigate patterns in individual data sets (relative humidity, shortwave irradiance, wind direction, air temperature) to identify the arrival date of the smoke plume. Describe the correlations between the different data types presented.
  • LO3. Name and interpret wind direction.
  • LO4. Investigate patterns in individual data sets (sea surface temperature, backscatter, CDOM) to identify the ocean response to the smoke plume. Describe the correlations between the different data types presented.
  • LO5. Make connections between wildfires and algal blooms (chlorophyll a, dissolved oxygen) and explore the consequences of these blooms for the ocean and society.
  • LO65-Extension. Develop skills in Python.

Background Information

Review concepts:

Key terms: phytoplankton, CDOM, chlorophyll, nitrate, wildfire plume, eutrophication, dissolved oxygen, harmful algal bloom (HAB), optical backscatter, irradiance, sea surface temperature

What is in wildfire smoke?

Data collection: We will use data collected by the Ocean Observatories Initiative (OOI), an initiative that has stationed equipment for collecting data in different locations around the world. Our data comes from the Coastal Endurance Array off the coast of the northwestern part of the USA (see map below).

Image of global OOI array locations.

Figure 12.0.2 Global OOI Array Locations

In order to view the events with the greatest clarity, we have opted to use two different moorings within the Coastal Endurance Array: The Oregon Offshore Surface Mooring and the Oregon Inshore Surface Mooring.

Diagram showing the cross sectional view of the Endurance Array Oregon line.

The Coastal Endurance Array is designed to observe cross-shelf and along-shelf variability in the region. The three sites across the shelf and slope are associated with characteristic physical, geological, and biological processes. All six sites contain fixed sensors at the top and bottom of the water column paired with an adjacent water column profiler. Four of the sites have a Bulk Meteorology Instrument package, and all six sites contain fixed sensors at the top and bottom of the water column paired with an adjacent water column profiler.

Activities in this Lab

Instructor Guide

 

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