A new NASA visualization sheds light on the role of aerosols—tiny atmospheric particles that have a significant impact on Earth’s temperature. Created using data from the Goddard Earth Observing System, the visualization tracks major aerosol types such as sulfates, black carbon, dust, and sea salt from August 1 to September 14, 2024. By integrating satellite data, ground-based observations, and advanced simulations, this tool illustrates how aerosols can influence air quality and visibility across vast distances, underscoring their importance in understanding climate changes.
Aerosols are crucial contributors to climate dynamics, distinct from greenhouse gases, which linger for years and have a global reach. Instead, aerosols typically remain airborne for only a few days and form regional plumes. They counteract climate warming through two primary mechanisms: reflecting solar radiation back into space and acting as condensation nuclei, which increase the number of droplets in clouds. This dual action has offset approximately one-third of temperature rises attributed to climate change, accounting for nearly half a degree Celsius of cooling, according to atmospheric scientist Sarah Doherty from the University of Washington.
The newly released visualization categorizes aerosols with distinct color codes for easy identification: sulfates appear in green, black carbon in red, dust in purple, and sea salt in teal. Sulfates, often linked to fossil fuel combustion—most notably coal—remain particularly prevalent in regions with heavy coal reliance, such as many Asian countries. Although coal use has been reduced in the United States, global coal consumption persists. Furthermore, natural events like volcanic eruptions significantly contribute to sulfate levels, as exemplified by the 1991 eruption of Mount Pinatubo, which massively distributed sulfates across the globe.
Saharan dust, represented in purple within the visualization, is the largest source of atmospheric dust globally. Trade winds transport this dust across the Atlantic, where it may fertilize the Amazon rainforest and possibly inhibit hurricane activity by limiting atmospheric moisture circulation. In contrast, black carbon, showing as red in the visualization, differs from most aerosols; it absorbs solar radiation instead of reflecting it, contributing to climate warming. Major sources of black carbon include biomass burning in sub-Saharan Africa and wildfires in the Amazon and North America, highlighting the complex interplay between pollution and climate systems.
Sea salt aerosols, depicted in teal, are generated through wind activity and ocean waves. Their abundance is closely correlated with wind speed; for instance, considerable amounts are generated in the Southern Ocean, where strong winds known as the Roaring Forties circulate with little obstruction. The dynamics of sea salt aerosols serve to illustrate how natural forces contribute to aerosol distribution and ultimately affect climate patterns.
As global efforts to reduce air pollution intensify, the cooling effects of aerosols are projected to decline. This shift may already be contributing to an accelerated rate of warming observed in recent years. Doherty notes that some analyses indicate the increasing rate of climate warming can be partially attributed to the decreasing presence of aerosols in the atmosphere. This ongoing transformation in aerosol levels signals a potential change in Earth’s climate trajectory, underscoring the necessity for continuous monitoring and research to understand these atmospheric particles’ long-term implications for our planet’s future climate.
