The continent of Asia experiences monsoon frequently and depends on it for their water needs. However, a new study suggests that in the advent of climate change, this can change drastically.
CONTINENTAL CRISIS
The monsoon that frequents the Asian continent is closely linked to a planetary-scale tropical airflow. A new study conducted by a research team from the Lawrence Berkeley National Laboratory suggests that this airflow will most likely shift geographically as the climate continues to warm which will eventually lead to less rainfall in certain regions.
Wenyu Zhou, Da Yang, along with Shang-Ping Xie of Scripps Institution of Oceanography at the University of California San Diego, teamed up to turn different global climate models to study the phenomenon where the air rises to the atmosphere near the equator, flows toward the poles, returns to the subtropics, and eventually flows back to the equator—the Hadley Cell.
The results, which were published in Nature Climate Change, show that the East Asian monsoon will most likely shift geographically as temperature rises.
On normal conditions, the Hadley cell consists of two components: the moist air that ascends at the equator causing heavy rainfall and the dry air that descends to the subtropics bringing dry conditions. Under human-induced climate change and global warming, the dry temperature of the subtropics will expand to the poles while the moist tropical part will get relatively smaller.
To get meaningful results for this study, the research team used the worst-case climate change scenario of the United Nations Intergovernmental Panel on Climate Change and get a glimpse and model the climate in the last 30 years of the 21st century.
In investigating the activities in the Hadley cell, the researchers found out that the Asian monsoon will move towards the equator. In the press release issued by Lawrence Berkeley National Laboratory, Zhou explains, "Previous studies suggested that, on average, the Hadley cell will expand poleward in warmer climates. However, we show different behavior in the summer months-a contraction towards the equator in June-July, due to the effect of the enhanced warming at the equator." Co-author Da Yang also explains that this movement will most definitely cause a big impact on water resource management countries like China and the people living in the area.
With the results of this study, the research team will investigate next the effect of the changes in the Hadley cell on other regions of the planet, such as the North American monsoon and hurricanes.
Preliminary results of the study show that the patterns over the last 30 years are dominated by natural variability, and the actual effect of global warming is yet to be seen.
