TY - JOUR
T1 - Modulations of the diurnal cycle of coastal rainfall over South China caused by the boreal summer intraseasonal oscillation
AU - Chen, Xingchao
AU - Zhang, Fuqing
AU - Ruppert, James H.
N1 - Funding Information:
Acknowledgments. This study is partially supported by NSF Grants AGS-1305798 and 1712290, and the DOE subcontract to Penn State through the Pacific Northwest National Laboratory. Computing is partly performed at the Texas Advanced Computer Center. An animation of Fig. 4 can be downloaded from http://hfip.psu.edu/xzc55/ 500hpa_anomaly.gif. The authors thank the three anonymous reviewers for their detailed and valuable suggestions.
Publisher Copyright:
© 2019 American Meteorological Society.
PY - 2019/4/1
Y1 - 2019/4/1
N2 - The influence of the boreal summer intraseasonal oscillation (BSISO) on the diurnal cycle of coastal rainfall over south China during the mei-yu (heavy rainfall) season is investigated using the OLR-based Madden- Julian oscillation index (OMI), satellite rainfall data, and atmospheric reanalysis. Results show that the meiyu season coastal rainfall is enhanced during the BSISO phase 1 (convectively active phase over the western Indian Ocean), with 25% greater rainfall than the climatological regional mean. Rainfall is suppressed during the BSISO phases 4 and 5 (convectively active phase in the Bay of Bengal and South China Sea), with negative rainfall anomalies of 39% and 46%, respectively. During phase 1, the rainfall enhancement is mostly over the inland region during the afternoon, while there is little diurnal variability of the rainfall anomaly offshore. During phases 4 and 5, the rainfall suppression is considerably stronger over the offshore region in the morning, whereas stronger rainfall suppression occurs inland during the afternoon. In phase 8, positive rainfall anomalies are found over the offshore region with a peak from the morning to the early afternoon, whereas negative rainfall anomalies are found over the inland region with the strongest suppression in the late afternoon. Analysis of phase composites and horizontal moisture advection shows that the diurnal variation of rainfall anomalies over the south China coastal area during different BSISO phases can be interpreted as the interaction between the large-scale anomalous moisture advection and the local land and sea breeze circulations.
AB - The influence of the boreal summer intraseasonal oscillation (BSISO) on the diurnal cycle of coastal rainfall over south China during the mei-yu (heavy rainfall) season is investigated using the OLR-based Madden- Julian oscillation index (OMI), satellite rainfall data, and atmospheric reanalysis. Results show that the meiyu season coastal rainfall is enhanced during the BSISO phase 1 (convectively active phase over the western Indian Ocean), with 25% greater rainfall than the climatological regional mean. Rainfall is suppressed during the BSISO phases 4 and 5 (convectively active phase in the Bay of Bengal and South China Sea), with negative rainfall anomalies of 39% and 46%, respectively. During phase 1, the rainfall enhancement is mostly over the inland region during the afternoon, while there is little diurnal variability of the rainfall anomaly offshore. During phases 4 and 5, the rainfall suppression is considerably stronger over the offshore region in the morning, whereas stronger rainfall suppression occurs inland during the afternoon. In phase 8, positive rainfall anomalies are found over the offshore region with a peak from the morning to the early afternoon, whereas negative rainfall anomalies are found over the inland region with the strongest suppression in the late afternoon. Analysis of phase composites and horizontal moisture advection shows that the diurnal variation of rainfall anomalies over the south China coastal area during different BSISO phases can be interpreted as the interaction between the large-scale anomalous moisture advection and the local land and sea breeze circulations.
UR - http://www.scopus.com/inward/record.url?scp=85064204548&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85064204548&partnerID=8YFLogxK
U2 - 10.1175/JCLI-D-18-0786.1
DO - 10.1175/JCLI-D-18-0786.1
M3 - Article
AN - SCOPUS:85064204548
SN - 0894-8755
VL - 32
SP - 2089
EP - 2108
JO - Journal of Climate
JF - Journal of Climate
IS - 7
ER -