The subtropics are global hotspots of climate change, yet climate model simulations and projections for these regions remain highly uncertain. These regions are home to a large share of the world's population, including many communities with the least historical GHG emissions that are disproportionately exposed to extreme events and climate change. As a zone of interaction between tropical and extratropical circulation regimes, the subtropics are characterised by a unique hydroclimate, with strong spatial gradients, distinct seasonal cycles, and high sensitivity to climate variability and change. Despite their importance for both society and the climate system, subtropical weather and climate processes remain comparatively understudied. This session invites contributions that advance process understanding and prediction of weather and climate with a particular focus on the subtropics. We welcome studies based on observations, theory, numerical models, and machine learning. Topics of interest include, but are not limited to:
- Atmospheric processes, such as tropical–extratropical interactions, subtropical jet fluctuations, Rossby wave dynamics, transient eddies, monsoon circulations, and convergence zones, shaping surface weather, clouds, and transport of dust and air pollution.
- Weather, climate, and compound extremes – droughts, heatwaves, wildfires, heavy precipitation, floods, dust storms, and windstorms – spanning their drivers, future changes, and impacts on society and ecosystems.
- The water cycle – rainfall, evapotranspiration, and moisture transport – modulated by weather systems such as cyclones, cut-off lows, cold air outbreaks, mesoscale convective systems, easterly waves, atmospheric rivers, and cloud bands.
- Coupled interactions between Earth system components, including land-atmosphere and ocean-atmosphere feedbacks, and the role of sea surface temperature patterns in shaping subtropical climate.
- Climate variability and remote linkages with ENSO, the Madden-Julian Oscillation (MJO), and the Hadley circulation.
- Observations and climate model simulations addressing past and future changes in regional circulation patterns and surface weather, and novel approaches for identifying model biases and for reducing uncertainties in projections.