Impact of diurnal temperature and relative humidity hysteresis on atmospheric dryness in changing climates
Journal
Science Advances
Series/Report No.
Science Advances
Journal Volume
11
Journal Issue
26
Date Issued
2025-06-27
Author(s)
Abstract
Vapor pressure deficit (VPD), a key indicator of atmospheric dryness, is strongly influenced by diurnal cycles of temperature (T) and relative humidity (RH). While these cycles are typically inversely locked in-phase, recent research has identified diurnal hysteresis, characterized by a time lag between T and RH; yet, its impact on VPD under changing climates remains poorly understood. In this study, we examine how diurnal T/RH hysteresis modulates VPD across different climates using observational data alongside high-resolution reanalysis and simulations. Here, we find that regions exhibiting strong diurnal T/RH hysteresis, especially in some waterside and montane regions, experience earlier daily VPD peaks. We also demonstrate that global warming weakens diurnal T/RH hysteresis, leading to amplified VPD increasing trends and greater ecosystem stress. These results highlight the need for improved representation of diurnal T/RH interactions in climate models to better predict atmospheric dryness and its impacts on land-atmosphere feedbacks, ecosystems, and regional water cycles.
Subjects
Atmospheric humidity
Atmospheric temperature
Climate models
Ecosystems
Hysteresis
Changing climate
Diurnal cycle
Diurnal temperatures
Humidity hysteresis
In-phase
Key indicator
Recent researches
Temperature and relative humidity
Time lag
Vapor pressure deficit
adult
article
circadian rhythm
climate
climate model
controlled study
greenhouse effect
hysteresis
physiological stress
simulation
temperature
vapor pressure
water cycle
Global warming
Type
journal article