New study shows highly different responses of surface vs air temperature following deforestation

At the location of a hypothetical deforestation, temperature measured at the surface (T_surf) and measured 2 m above the surface (T_2m) change differently. The figure demonstrates this separately for mean daily minimum temperature (T_min) and mean daily maximum temperature (T_max).

In a new study published recently in Earth System Dynamics and highlighted in Nature Climate Change, scientists in the department “The Land in the Earth System” at the Max Planck Institute for Meteorology (MPI-M) – Dr Johannes Winckler, Dr Christian Reick, Marvin Heidkamp, Dr Andreas Chlond, Dr Thomas Raddatz and Prof Julia Pongratz – together with colleagues from other institutes investigate how deforestation affects temperature and how surface and air temperature respond differently to deforestation.

Deforestation influences the exchange of moisture and heat between the land surface and the atmosphere (the so-called biogeophysical effect). This, in turn, can alter temperature. It is important whether deforestation influences the temperature at the surface, the air temperature, or the temperature higher up in the atmosphere because these different heights matter for living conditions of humans and other organisms in different ways. However, many studies that focus on the biogeophysical deforestation effects tend to use these different temperature measure interchangeably and report just one or the other. In this new study, the authors use simulations with a climate model to investigate the response of both surface and air temperature and compare its strength. They do so separately for temperature changes at the location of deforestation (‘local effects’), and elsewhere (‘nonlocal effects’).

The authors find that while nonlocal effects influence surface and air temperature similarly, the local effects generally influence surface temperature more strongly than atmospheric temperature, especially for daily maximum temperatures. The authors compare results across different climate models, and show that both for summer warming and winter cooling the surface temperature change exceeds the air temperature change locally by a factor of two. This study clearly highlights that temperature definition is important, when investigating the temperature effects of deforestation.

 

Original publication:
Winckler, J., Reick, C. H., Heidkamp, M., Chlond, A., Raddatz, T., Pongratz, J., et al. (2019). Different response of surface temperature and air temperature to deforestation in climatemodels. Earth System Dynamics, 10, 473–484. https://doi.org/10.5194/esd-10-473-2019

Link to Nature Climate Change: https://www.nature.com/articles/s41558-019-0573-y

 

Contact:

Dr Johannes Winckler
Max Planck Institute for Meteorology
Email: johannes.winckler@we dont want spammpimet.mpg.de

Dr. Christian Reick
Max-Planck-Institut für Meteorologie
E-Mail: christian.reick@we dont want spammpimet.mpg.de


Prof Dr Julia Pongratz
Max Planck Institute for Meteorology
Email: julia.pongratz@we dont want spammpimet.mpg.de