Nav: Home

Rainy season tends to begin earlier in Northern Central Asia

June 02, 2020

Researchers from the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Science (CAS) found that the rainy season of northern Central Asia, which occurs in May-July in present-day, will shift to March-May at the end of the 21st century. The study was published in Environmental Research Letters.

Central Asia is characterized by scarce precipitation and high evaporation. People's livelihoods and the fragile ecosystem are highly sensitive to changes in local precipitation.

"This region is one of the hot spots of global warming, where a stronger than global mean warming trend is projected in the coming century. But the future precipitation changes are less clear," said Jie Jiang from IAP, the paper's first author. "Besides the amount of precipitation, the changes in the phase of precipitation also affect agriculture and other fields."

To give a comprehensive picture of the future changes in precipitation over Central Asia, the researchers adopted the multimodel simulations and projections of 15 models from the new phase of the Coupled Model Intercomparison Project (CMIP6).

They also used projections under four combined scenarios of the Shared Socioeconomic Pathways and the Representative Concentration Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5). These scenarios reflected a set of alternative futures of social development and greenhouse gas emission.

The researchers found robust increase of annual mean precipitation at the end of the 21st century under all scenarios. The increasing rate was about 14.41% for the highest emission scenario (SSP5-8.5) and near 4.23% for the lowest emission scenario (SSP1-2.6) relative to present-day. The model spread was larger for higher emission scenarios, which could be partly attributed to the larger uncertainty of the surface air temperature.

Further analysis revealed a wetting trend in spring and a drying trend in summer, which would result in enhanced seasonality of precipitation over Central Asia and a shift of the rainy season in the northern Central Asia. The increase of precipitation in spring was balanced by increasing evaporation, while the decrease in summer was mainly due to the changes in vertical moisture advection.

"Central Asia is dominated by descending motion and low-level divergence in summer. The increase of atmospheric water vapor due to rapid warming can result in the decrease of vertical moisture advection and contributes to the drying trend in summer, which is the so-call dry-getting-drier mechanism," Jiang explained. "In addition, the changes in the location and strength of subtropical westerly jet due to anthropogenic activity can also affect the annual cycle of precipitation."

The researcher also discussed the changes in drought condition over this drought-prone region. Based on the Surface Wetness Index (SWI), they found drought might become even severer in the coming century though increasing precipitation was projected. "Adaptation measure for future climate changes should consider both the shift of rainy season and increased aridity over this region," Jiang said.
-end-
This work was supported by the Chinese Academy of Sciences and National Natural Science Foundation of China.

Institute of Atmospheric Physics, Chinese Academy of Sciences

Related Precipitation Articles:

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).
Steep momentum gradients play a major role in coastal precipitation
Steep gradients of wind stress and potential temperature enable sustainable nearshore precipitation systems along the western coastal region of Korea.
Increasing precipitation extremes driving tree growth reductions across southwest
As the Earth's temperature warms, its hydrological cycle kicks into overdrive - wet years get wetter, and dry years get drier.
Extreme flooding from storm surge and heavy precipitation projected to increase higher probability of compound flooding from precipitation and storm surge in Europe under anthropogenic climate change
Risk of compound flooding, which can result when rapid sea level rises associated with storms occur along with heavy rains, is currently concentrated along Mediterranean countries but will greatly increase for Northern European in the future as the climate warms, according to a new modeling study.
NASA reveals heavy rainfall in Tropical Cyclone Fani
Satellite data revealed heavy rainfall in powerful Tropical Cyclone Fani before it made landfall in northeastern India.
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

Our Relationship With Water
We need water to live. But with rising seas and so many lacking clean water – water is in crisis and so are we. This hour, TED speakers explore ideas around restoring our relationship with water. Guests on the show include legal scholar Kelsey Leonard, artist LaToya Ruby Frazier, and community organizer Colette Pichon Battle.
Now Playing: Science for the People

#568 Poker Face Psychology
Anyone who's seen pop culture depictions of poker might think statistics and math is the only way to get ahead. But no, there's psychology too. Author Maria Konnikova took her Ph.D. in psychology to the poker table, and turned out to be good. So good, she went pro in poker, and learned all about her own biases on the way. We're talking about her new book "The Biggest Bluff: How I Learned to Pay Attention, Master Myself, and Win".
Now Playing: Radiolab

Uncounted
First things first: our very own Latif Nasser has an exciting new show on Netflix. He talks to Jad about the hidden forces of the world that connect us all. Then, with an eye on the upcoming election, we take a look back: at two pieces from More Perfect Season 3 about Constitutional amendments that determine who gets to vote. Former Radiolab producer Julia Longoria takes us to Washington, D.C. The capital is at the heart of our democracy, but it's not a state, and it wasn't until the 23rd Amendment that its people got the right to vote for president. But that still left DC without full representation in Congress; D.C. sends a "non-voting delegate" to the House. Julia profiles that delegate, Congresswoman Eleanor Holmes Norton, and her unique approach to fighting for power in a virtually powerless role. Second, Radiolab producer Sarah Qari looks at a current fight to lower the US voting age to 16 that harkens back to the fight for the 26th Amendment in the 1960s. Eighteen-year-olds at the time argued that if they were old enough to be drafted to fight in the War, they were old enough to have a voice in our democracy. But what about today, when even younger Americans are finding themselves at the center of national political debates? Does it mean we should lower the voting age even further? This episode was reported and produced by Julia Longoria and Sarah Qari. Check out Latif Nasser's new Netflix show Connected here. Support Radiolab today at Radiolab.org/donate.