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Climate Change 2016
October 27-29, 2016
Volume 7, Issue 9(Suppl) J Earth Sci Clim Change
ISSN: 2157-7617 JESCC, an open access journal
conferenceseries .com
October 24-26, 2016 Valencia, Spain
World Conference onClimate Change
Evolutions of the circulation anomalies and the quasi-biweekly oscillations associated with extreme
heat events in South China
Ruidan Chen
Sun Yat-sen University, China
S outh China, located in the tropical-subtropical East Asian monsoonal region, presents a unique anticyclonic-cyclonic
circulation pattern during extreme heat (EH), obviously different from the typical anticyclone responsible for EH in
many other regions. Associated with the evolution of EH in South China, the anticyclonic-cyclonic anomalies propagate
northwestwards over the Philippines and South China. Before the EH onsets, the anticyclonic anomaly dominates South
China, and results in stronger subsidence over South China and stronger southerly/southwesterly over the western/northern
margins of South China. The southerly/southwesterly transports more water vapor to the north of South China, and together
with the local stronger subsidence result in dry air condition and accordingly favor the EH occurrence. Conversely, after the
EH onsets, the cyclonic component approaches South China and offsets the high temperature. The oscillations of temperature
and circulation anomalies over South China exhibit a periodicity of ~10 days and indicate the influence of quasi-biweekly
oscillation (QBWO), which originates from the tropical western Pacific and propagates northwestwards. Therefore, the 5–25-
day filtered data are extracted to further analyze QBWO. It turns out that the evolutions of the filtered circulation remarkably
resemble the original anomalies with comparable amplitudes, indicating the QBWO is critical for EH occurrence. The QBWO
could explain for 50% of the intra-seasonal variance of Tmax and vorticity over South China, and 70% of the warming amplitude
on EH onsets. The close relationship between the circulations of QBWO and the EH occurrence indicates the possibility of
medium-range forecast for high temperature in South China.
Biography
Ruidan Chen has completed her PhD from the Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China. She is a lecturer in Sun Yat-sen
University School of Atmospheric Sciences, Guangzhou, China. She has published 7 papers in reputed journals.
Ruidan Chen, J Earth Sci Clim Change 2016, 7:9(Suppl)