Large anomalies in future extreme precipitation sensitivity driven by atmospheric dynamics

Area of Science:

• Climate Science
• Atmospheric Physics
• Extreme Weather Events

Background:

• Global warming increases atmospheric moisture, intensifying precipitation extremes.
• Extreme precipitation sensitivity (EPS) to temperature is complex, with unclear physical mechanisms.
• Previous studies lacked a detailed physical decomposition of EPS.

Purpose of the Study:

• To physically decompose extreme precipitation sensitivity (EPS) into thermodynamic and dynamic components.
• To analyze EPS at a global scale using historical and future climate projections.
• To clarify the roles of atmospheric moisture and vertical ascent velocity in precipitation extremes.

Main Methods:

• Utilized atmospheric reanalysis data.
• Employed climate model projections for future climate scenarios.
• Developed a physical decomposition framework for EPS.

Main Results:

• Thermodynamics do not always intensify precipitation; lapse rate and pressure effects can offset warming.
• Future EPS anomalies are primarily driven by changes in updraft strength (dynamic component).
• Observed contrasting EPS anomalies over oceans (positive) and land (negative).

Conclusions:

• Counteracting effects of atmospheric thermodynamics and dynamics influence EPS.
• Updraft strength is a critical factor in future precipitation extreme projections.
• Decomposing thermodynamic effects is crucial for understanding precipitation extremes.