Object-Oriented Analysis Yields Compounding Short-Term Drought and Crop Heat-Stress Events
We analyzed for a north-central U.S. region, short-term drought and agricultural heat stress during April-May-June-July, using observed and simulated contemporary climates (1981-2000) and simulated mid-century future climates (2041-2060). We identified events of interest in observations and simulations by diagnosing objects in a space-time domain that met specified criteria, such as exceeding a heat-stress temperature threshold. The event diagnosis allowed analysis of compound events, occurring when temperature and drought objects overlap.
Crops are vulnerable to precipitation and heat extremes from late spring through summer. A changing climate could impact efforts to plan for such events and thus mitigate their influences.
Identified objects yielded events that can undermine agricultural productivity and which are thus relevant to decision-makers, making them building blocks for possible climate storylines. The information yielded projected changes in these agriculturally motivated events. Short-term drought frequency increased and heat-stress frequency decreased in transitioning to the scenario climate. When compounding occurred, heat-stress events generally preceded the short-term drought events, and thus a prominent conditional behavior emerging from the work was that a heat-stress event should be a warning to watch for potential drought, as both could compound each other to more intense levels.