Thirstwave ( UPSC Prelims)

News Context

• Periods of intense atmospheric thirst (high evaporative demand) that quickly dehydrate the landscape.
    o While a heatwave is characterized by high temperature, a thirstwave is characterized by high dryness and the air's intense demand for moisture.
 • Technically, a thirstwave occurs when there are at least 3 consecutive days where the daily evaporative demand exceeds its historical 90th percentile value for that time period.
    o Evaporative demand is an indicator of how thirsty the atmosphere is.
    o Factors influencing evaporative demand include temperature, wind speed, humidity, and sunshine.