Detectable global temperature responses to wildfires and volcanic eruptions.

Area of Science:

• Atmospheric Science
• Climate Science
• Earth System Science

Background:

• Volcanic eruptions and wildfires are major natural forcings impacting Earth's atmospheric temperature.
• While sulfate aerosols from volcanoes are well-studied, the climate effects of wildfire smoke and water vapor from submarine eruptions are less understood.
• Accurate climate response assessment requires understanding all natural forcings, including less-studied ones.

Purpose of the Study:

• To detect and attribute atmospheric temperature impacts from natural forcings like volcanic eruptions and wildfires.
• To analyze the distinct climate fingerprints of landmark events: Pinatubo eruption (1991), Australian wildfires (2019-2020), and Hunga Tonga eruption (2022).
• To improve climate model simulations by accounting for diverse natural forcings.

Main Methods:

• Utilizing multidecadal satellite observations.
• Employing climate model ensembles for internal variability estimation.
• Analyzing temperature anomalies in the troposphere and stratosphere.

Main Results:

• Robust detection of statistically significant temperature anomalies in both troposphere and stratosphere.
• Australian wildfires left a detectable stratospheric signal despite lower aerosol mass compared to Pinatubo.
• Hunga Tonga eruption caused significant, prolonged stratospheric cooling but no robust tropospheric signal in the first two years.

Conclusions:

• Both sulfate and non-sulfate stratospheric perturbations create distinct, identifiable global temperature signals.
• Wildfire smoke and water vapor injections can significantly impact atmospheric temperature.
• Incorporating these diverse natural forcings into climate models is crucial for accurate simulations and comparisons with observations.