Nav: Home

Tropical cyclone- and monsoon-induced rainfall variability over southern China

November 22, 2016

Southern China (SC) belongs to the East Asian summer monsoon region. Climatological rainfall over SC has two peaks, one appearing in April-June and the other in August-September. These peaks are mainly associated with the summer monsoon and the passage of tropical cyclones (TCs), respectively. TCs forming in the South China Sea (SCS) contributed to an increase in SC summer rainfall around 1993. In Taiwan, tropical cyclone-induced precipitation (PTC) and summer monsoon-induced precipitation (PSM) tend to vary inversely on both interdecadal and interannual time scales. Although SC and Taiwan are situated at almost the same latitude, scientists from Sun Yat-Sen University and South China Sea Institute of Oceanology pointed out that the relationship over SC between PTC and PSM is different from that in Taiwan. The results are published in Atmospheric and Oceanic Science Letters.

The spatial patterns of the first interannual mode are uniform in sign over SC, with positive anomalies for PTC and negative anomalies for PSM. The background of an increase in cyclonic vorticity, an increase in RH, and a decrease in vertical wind shear over the South China Sea (SCS)-western north Pacific (WNP) provides favorable conditions for more TC genesis. The positive equatorial central Pacific SST anomaly and negative North Indian Ocean SST anomaly contribute to the anomalous cyclone over the SCS-WNP, which causes decreasing PSM in SC together with an anomalous anticyclone over eastern China-Japan.

By contrast, the interdecadal eigenvectors feature uniform patterns with positive anomalies for both PTC and PSM. During the preceding winter and spring after the early 1990s, a positive western Pacific SST anomaly can result in tropical Indian Ocean (TIO) SST warming through vertical circulation. Then, the positive TIO SST anomaly triggers an anomalous WNP anticyclone and contributes to the interdecadal increase in SC PSM in the succeeding summer. The increase in PTC over SC is related to more TCs forming in the SCS. The above results help us to gain greater insight into the variability of SC summer rainfall through separating total rainfall into PTC and PSM.
-end-


Institute of Atmospheric Physics, Chinese Academy of Sciences

Related Tropical Cyclones Articles:

Stronger tropical cyclones strengthen the Kuroshio Current, further heating high latitudes
As the intensity and frequency of the strongest cyclones east of Taiwan have increased, so has the strength of the Kuroshio current, a Pacific current responsible for redistributing heat throughout the western North Pacific Ocean.
Cyclones can damage even distant reefs
Big and strong cyclones can harm coral reefs as far as 1000 kilometres away from their paths, new research shows.
Study: Climate change has been influencing where tropical cyclones rage
While the global average number of tropical cyclones each year has not budged from 86 over the last four decades, climate change has been influencing the locations of where these deadly storms occur, according to new NOAA-led research published in Proceedings of the National Academy of Science.
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.
NASA measures rainfall rates in two American Samoa Tropical Cyclones
There are two tropical cyclones affecting American Samoa in the South Pacific Ocean on Feb.
Tropical cyclones: How they contribute to better forecast in the Maritime Continent
Tropical cyclones in the North West Pacific can dry the archipelagos of Southeast Asia, as they reduce humidity in the area with their associated winds.
A simple way to predict tropical cyclones undergoing rapid intensification
Scientsits propose a simple way to predict tropical cyclones undergoing rapid intensification.
Looking at tropical forests through new eyes
New University of Arizona-led science is using air-based maps of plant chemistry to improve carbon cycling models in hyperdiverse tropical forests.
NASA catches Tropical Cyclone Gelena's post-tropical transition
Tropical cyclones can become post-tropical before they dissipate, meaning they can become sub-tropical, extra-tropical or a remnant low pressure area.  As Tropical Cyclone Gelena transitioned into a subtropical storm, NASA's Aqua satellite provided a visible image of the storm.
NASA sees Tropical Storm Man-yi approaching typhoon strength Tropical Storm Man-Yi con
Tropical Storm Man-Yi continued to strengthen in the Northwestern Pacific Ocean as NASA-NOAA's Suomi NPP satellite provided a visible image of the storm.
More Tropical Cyclones News and Tropical Cyclones 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

Making Amends
What makes a true apology? What does it mean to make amends for past mistakes? This hour, TED speakers explore how repairing the wrongs of the past is the first step toward healing for the future. Guests include historian and preservationist Brent Leggs, law professor Martha Minow, librarian Dawn Wacek, and playwright V (formerly Eve Ensler).
Now Playing: Science for the People

#566 Is Your Gut Leaking?
This week we're busting the human gut wide open with Dr. Alessio Fasano from the Center for Celiac Research and Treatment at Massachusetts General Hospital. Join host Anika Hazra for our discussion separating fact from fiction on the controversial topic of leaky gut syndrome. We cover everything from what causes a leaky gut to interpreting the results of a gut microbiome test! Related links: Center for Celiac Research and Treatment website and their YouTube channel
Now Playing: Radiolab

The Flag and the Fury
How do you actually make change in the world? For 126 years, Mississippi has had the Confederate battle flag on their state flag, and they were the last state in the nation where that emblem remained "officially" flying.  A few days ago, that flag came down. A few days before that, it coming down would have seemed impossible. We dive into the story behind this de-flagging: a journey involving a clash of histories, designs, families, and even cheerleading. This show is a collaboration with OSM Audio. Kiese Laymon's memoir Heavy is here. And the Hospitality Flag webpage is here.