Publications

Leung, GR; Grant, LD; van den Heever, SC (2024). Deforestation-Driven Increases in Shallow Clouds Are Greatest in Drier, Low-Aerosol Regions of Southeast Asia. GEOPHYSICAL RESEARCH LETTERS, 51(10), e2023GL107678.

Abstract
Anthropogenic activity drives extensive tropical deforestation, particularly in Southeast Asia where 16% of total forest cover was lost between 2000 and 2020. While land surface changes significantly affect the atmosphere, their net impact on convective clouds is not well-constrained. Here, we use satellite data to demonstrate long-term deforestation in Southeast Asia robustly alters cloud properties and provide the first observational evidence that the magnitude of this response depends on the atmospheric environment. Deforestation drives a shift toward more widespread, shallower clouds during the daytime, with amplified effects in dry inland areas compared with moist coastal regions. Aerosols only weakly modulate the cloud fraction response, but offset the cloud top height response to deforestation, suggesting the influence of aerosol indirect effects. We conclude that the local signature of forest loss is not uniform, and regional differences in climatology must be considered when assessing deforestation impacts on clouds and the climate system. Humans are driving widespread deforestation in the tropics. Changes to the land surface following forest loss are generally known to affect the atmosphere, but it is hard to tell how deforestation will impact clouds in a given area. Here, we focus on Southeast Asia, a region of the world facing dramatic large-scale deforestation. We use two decades of satellite data to estimate how the loss of tropical forests impacts cloud properties. On average, we find that deforestation leads to more widespread and shallower clouds. We then look further into how this cloud response to deforestation depends on other environmental factors like moisture and aerosols. This gives us a better idea of which regions are most sensitive to changes in forest cover. Overall, our results show there is an observable cloud response to deforestation, but this response may be stronger in some regions than in others depending on underlying moisture and aerosol conditions. As forest loss continues in Southeast Asia and across the world, it is important to further study these region-dependent interactions between the atmosphere and the land surface so we can better understand the impacts of human-driven deforestation on weather and climate. Deforestation in Southeast Asia drives a robust shift toward more widespread and shallower clouds on an annual timescale This effect has been debated in modeling studies, but we demonstrate this observationally using two decades of satellite data Some regions are especially vulnerable to deforestation-driven changes in clouds, depending on atmospheric moisture and aerosol loading

DOI:
10.1029/2023GL107678

ISSN:
1944-8007