Exploring Atmospheric Dust & Climate

This facilitated program, developed in conjunction with the NSF funded project PIRE: DUST stimulated draw-down of atmospheric CO2 as a trigger for Northern Hemisphere Glaciation, provides an opportunity to learn about the connections between the Earth system and climate. Dust originates on land (the geosphere), is lofted into the atmosphere, enters the ocean (the hydrosphere), and ultimately helps to cool the climate by stimulating the growth of phytoplankton (the biosphere). These connections illustrate the importance of a multi-disciplinary scientific perspective to understanding the climate system and solutions for climate change.

Visualizations created using model data from MIT’s Darwin Ecosystem Model and Nullschool show the circulation of dust in the atmosphere and the concentration of chlorophyll, iron, and nitrate in the ocean throughout one calendar year. Together, they explain how iron-rich dust entering the ocean can affect the climate.

• Dust moves between the geosphere, atmosphere, and hydrosphere.
• The concentration of different minerals and nutrients in the ocean, such as iron and nitrate, varies by location and throughout the year.
• There are lower concentrations of iron in the North Pacific Ocean than in the Atlantic Ocean. Conversely, there are lower concentrations of nitrate in the Atlantic Ocean than in the North Pacific Ocean.
• Dust that enters the ocean increases the amount of iron available to marine organisms whose populations may be limited/restricted by lack of iron.
• In areas where there is not enough iron, dust entering the ocean leads to an increase in phytoplankton.
• Nitrates are another nutrient that can influence phytoplankton populations. More phytoplankton can live where there are higher nitrate concentrations.
• The presence of photosynthetic phytoplankton in the ocean is indicated by chlorophyll concentration: where there is more chlorophyll, there is more phytoplankton.
• The climate is influenced by the abundance of phytoplankton in the ocean because phytoplankton remove carbon dioxide from the atmosphere during photosynthesis.

• Docent Script
• Accompanying PowerPoint Presentation
• Playlist

In addition to this Science on a Sphere live program, there is a collection of educational materials about atmospheric dust and climate available at scied.ucar.edu/atmospheric-dust-climate.