EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Impact of Deforestation in the Maritime Continent on the Madden–Julian Oscillation

Chuing-Wen June Chang1, Min-Hui Lo2, Wan-Ling Tseng3, Yu-Cian Tsai4, and Jia-Yuh Yu4
Chuing-Wen June Chang et al.
  • 1Department of Atmospheric Sciences, Chinese Cultural University, Taipei, Taiwan (
  • 2Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan
  • 3International Degree Program in Climate Change and Sustainable Development, National Taiwan University, Taipei, Taiwan
  • 4Department of Atmospheric Sciences, National Central University, Taoyuan, Taiwan

Deforestation is a major issue affecting both regional and global hydroclimates. This study investigated the effect of deforestation in the Maritime Continent (MC) on tropical intraseasonal climate variability. Using a global climate model with Madden–Julian Oscillation (MJO) simulations, we examined the effect of deforestation over the MC region by replacing the forest canopy with grassland. The results revealed that under constant orographic and land–sea contrast forcing, the modification of the canopy over the MC altered the characteristics of the MJO. We noted the amplification of the MJO and increases in wet–dry fluctuation and the zonal extent. We analyzed more than 100 MJO cases by performing K-means clustering and determined that the continuous propagation of the MJO over the MC increased in 35% and 61% of the total 110 cases in the control and deforestation experiments, respectively. This phenomenon was associated with more substantial vanguard precipitation, increased soil moisture, and a suppressed diurnal cycle in land convection. Furthermore, when the MJO convection was over the Indian Ocean (IO), we observed the enhancement of low-level moisture over the MC region in the deforestation experiment. Grassland surface forcing provides a thermodynamic source for triggering instability in the atmosphere, resulting in low-level moisture convergence. The MJO exhibited a stronger energy recharge–discharge cycle in the deforestation experiment than in the control experiment, and this difference between the experiments enlarged from the IO to MC.


How to cite: Chang, C.-W. J., Lo, M.-H., Tseng, W.-L., Tsai, Y.-C., and Yu, J.-Y.: Impact of Deforestation in the Maritime Continent on the Madden–Julian Oscillation, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-6722,, 2023.