Understanding Drought Dynamics: Causes, Attribution, and Forecasting for Early Warning Systems

Drought is a recurring dry condition characterized by below-normal precipitation, often accompanied by warm temperatures, that can occur at temporal scales of weeks to years and spatial scales of cities to continents. Among all-natural calamities, droughts are ranked the most disastrous hazards seriously impacting our environment and economy. Droughts have far-reaching implications for water quality and supply, human health, food security, and the natural environment. Severe droughts are often linked to atmospheric blocking or anticyclonic circulations, which are usually a part of quasi-stationary Rossby waves. Anomalies in sea surface temperatures (SSTs) and teleconnections of distant forcings, such as large-scale climatic modes, typically generate and modulate such blockings of atmospheric flow and subsequently cause long-duration droughts. It is also suggested that El-Niño southern oscillation drives the global drought variability by modulating the global and mesoscale precipitation and temperature patterns. Besides these remote causal forcings, droughts are also linked to a variety of local factors including land-atmosphere feedback. In a warmer world, such causal factors (e.g., blocking) and the associated droughts are expected to be more frequent and intense, likely increasing the severity of their impacts.

This research topic aims to consolidate the state-of-the-art research on the theme “Droughts: causes, attribution, and forecasting,” highlighting the key scientific gaps in understanding meteorological and ecological droughts, their causal factors, attribution, monitoring, and forecasting for early warning systems. The main objectives include answering specific questions about the attribution of recent exceptional droughts to anthropogenic changes, natural climatic variations, and regional factors. Additionally, the research will test hypotheses related to the role of large-scale atmospheric circulation and the associated remote ocean conditions in initiating and propagating ecohydrological droughts.

To gather further insights into the complex dynamics of droughts, we welcome articles addressing, but not limited to, the following themes:
- Attribution of the recent exceptional droughts to anthropogenic changes, natural climatic variations, and regional factors.
- Seasonal forecasting of regional droughts using statistical/machine learning and dynamical approaches; development of early-warning systems for ecohydrological droughts based on sub-seasonal to seasonal (S2S) forecasts.
- The role of large-scale atmospheric circulation and the associated remote ocean conditions and the local feedback in initiating and propagating ecohydrological droughts at regional scales.
- Exploring teleconnections in meteorological droughts (i.e., droughts occurring in distant regions under specific weather regimes) and their governing physical mechanisms, including the role of atmospheric and oceanic circulations.