Nav: Home

Global warming will accelerate water cycle over global land monsoon regions

July 23, 2019

The global monsoon region, sprawling north and south from the Earth's equator, sustains nearly two-thirds of the world's population. It is characterized with abundant monsoon rainfall, a distinct wet-dry season contrast, and hence an active water cycle.

Future global warming would accelerate the water cycle over the entire global land monsoon region, meanwhile enlarge the wet-dry season contrast, according to a study recently published in Journal of Climate. The research reveals robust and coherent responses in the various aspects of water cycle to future warming over the populous global monsoon regions.

"The global monsoon regions deserve specific attention as they extensively affect the global water cycle," said Tianjun Zhou, the corresponding author on the paper. Zhou is a senior scientist at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics at the Institute of Atmospheric Physics and CAS Center for Excellence in Tibetan Plateau Earth Sciences in the Chinese Academy of Sciences. He is also a professor at the University of Chinese Academy of Sciences.

While there has been considerable research interest in the future changes in monsoon precipitation, limited attention has been paid to other aspects of the water cycle over the monsoon regions. Zhou and his team, using multi-model output from CMIP5, an archive of the state-of-the-art climate models, investigated and provided a comprehensive picture of water cycle changes over the monsoon regions, including both the atmospheric and surface water sectors, namely, precipitation, evaporation, surface fresh water fluxes, soil water, and total runoff (i.e., water flowing over and within the ground).

"Under future global warming, we will see an accelerated water cycle over the entire global monsoon region, as evidenced by the coherent increases in its various cycling fluxes, including the annual-mean precipitation, evaporation, total runoff and surface fresh water fluxes," Zhou introduced.

Moreover, the scientists found regional differences under the overall acceleration of water cycle. Specifically, the Northern Hemispheric African, South and East Asian monsoon regions will experience an intensified water cycle, while in the Northern Hemispheric American monsoon region, the water cycle would robustly be weakened. However, the changes in the Southern Hemispheric monsoon regions are largely uncertain.

"Apart from the spatial differences, the water cycle changes also vary with season," Zhou added. "The precipitation, runoff, and surface fresh water fluxes would increase most prominently in the wet season, but slightly reduce in the dry season. On one hand, this indicates an enlarged wet-dry season contrast in the monsoon regions. In terms of the human use of water resources, the changing seasonality can be described as 'wet season gets wetter, dry season gets drier'. On the other hand, there might be increasing flood risks in the wet season."

The water cycle includes both the cycling fluxes (i.e., movements) and reservoirs. The soil water, an important water reservoir in the Earth's surface, is also an indicator of agricultural drought. "The surface soil water would deplete all year round as a result of atmospheric warming. This could reduce crop yields and further threaten food security for the dense populations," Zhou added.

These results provide a broader understanding on the redistribution of freshwater resources across the globe induced by future changes in the monsoon system. Meanwhile, the authors are also calling for attention to the changing seasonality of the water cycle. "The seasonal changes are more remarkable and robust than the annual- mean changes," Zhou said. "We should be aware of and prepared for the potential additional flood and drought risks in the populous monsoon regions."
-end-
This work was supported by the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences, the International Partnership Program of Chinese Academy of Sciences, China Postdoctoral Science Foundation, and Ministry of Science and Technology of China.

Other contributors include Wenxia Zhang, Lixia Zhang, and Liwei Zou, all from the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics at the Institute of Atmospheric Physics of the Chinese Academy of Sciences. Lixia Zhang and Liwei Zou are also affiliated with the CAS Center for Excellence in Tibetan Plateau Earth Sciences in the Chinese Academy of Sciences.

Institute of Atmospheric Physics, Chinese Academy of Sciences

Related Precipitation Articles:

Spread of monsoon circulation changes explains uncertainty in global land monsoon precipitation projection
A new study emphasizes the importance of reliable prediction of circulation changes, to ensure that future projections of global land monsoon are suitable for use by policy makers.
GMMIP simulations on global monsoon interannual variability show higher skill than historical simulations
GMMIP simulations on global monsoon interannual variability show higher skill than historical simulations.
The spatial consistency of summer rainfall variability between the Mongolian Plateau and North China
The regional differences and similarities of precipitation variability are hotspots in climate change research.
Scientists find key factors impacting sideswiping tropical cyclone precipitation
Scientists find that the distribution of sideswiping tropical cyclones precipitation(STP) includes extreme STP events that appear not only over the island and coastal areas, but also over inland areas
Rainy season tends to begin earlier in Northern Central Asia
The researchers found robust increase of annual mean precipitation at the end of the 21st century under all modelling scenarios over northern central Asia.
Using cloud-precipitation relationship to estimate cloud water path of mature tropical cyclones
Scientists find the cloud water path of mature tropical cyclones can be estimated by a notable sigmoid function of near-surface rain rate.
Precipitation will be essential for plants to counteract global warming
A new Columbia Engineering study shows that increased water stress--higher frequency of drought due to higher temperatures, is going to constrain the phenological cycle: in effect, by shutting down photosynthesis, it will generate a lower carbon uptake at the end of the season, thus contributing to increased global warming.
Fall precipitation predicts abundance of curly top disease and guides weed management
Transmitted by an insect known as the beet leafhopper, curly top disease is a viral disease affecting many crops, including melons, peppers, sugar beets, and tomatoes.
Study confirms climate change impacted Hurricane Florence's precipitation and size
A new modeling framework showed that Hurricane Florence produced more extreme rainfall and was spatially larger due to human-induced climate change.
Study shows link between precipitation, climate zone and invasive cancer rates in the US
In a new study, researchers provide conclusive evidence of a statistical relationship between the incidence rates of invasive cancer in a given area in the US and the amount of precipitation and climate type (which combines the temperature and moisture level in an area).
More Precipitation News and Precipitation Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at Radiolab.org/donate.