Why is the atmosphere over land becoming drier?
My research investigates the roles of atmospheric processes and vegetation feedbacks, and their implications for future climate change.
Climate change is a long-term shift in the properties of our atmosphere. One of these properties is relative humidity. Relative humidity describes the amount of water vapour in the air, relative to the temperature of the air. Dry air has a low relative humidity, while fog has a high relative humidity. Observation data shows that relative humidity is decreasing globally over land since the year 2000, especially in regions of mid-latitudes.
My project will be exploring three possible causes, or drivers, for declining near surface relative humidity over land:
Dynamical drivers, so called modes of variability (eg wind and pressure pattern)
Thermodynamical drivers (temperature and, consequently, greenhouse gases)
Land-based drivers (transpiration of plants and large-scale land cover changes, such as deforestation)
I am working with global monitoring products and earth observation data for land use, evapotranspiration and soil moisture. I will also be using computer simulations based on this data, and ecosystem studies. I hope to find out more about water, the fundamental element for life, and the representation of atmosphere-land exchange processes in climate models that predict the future.
This interdisciplinary research is carried out in collaboration with the Climate Monitoring and Attribution Group of the Met Office.
Selected Publications:
Weber et al. "Why is the atmosphere over land becoming drier? Exploring the roles of atmospheric and land-surface processes on relative humidity." EGU General Assembly 2022.
GC41A-08 - Why is the atmosphere becoming drier? - An investigation of the role of dynamical drivers on recent trends in relative humidity (AGU Fall Meeting 2019)
Speaker at the House of Lords Chamber Debate, "Can we have sustainability alongside globalism and growth?", 2019.