The East Asian summer monsoon index (1851-2021)

The East Asian summer monsoon index (1851-2021)


The East Asian summer monsoon (EASM) and its variability involve circulation systems in both the tropics and midlatitudes as well as in both the lower and upper troposphere. Considering this fact, a new EASM index (NEWI) is proposed based on 200-hPa zonal wind, which takes into account wind anomalies in the southern (about 5°N), middle (about 20°N), and northern areas (about 35°N) of East Asia.

NEWI = Nor[u(2.5°–10°N, 105°– 140°E) - u(17.5°–22.5°N, 105°– 140E) + u(30°– 37.5°N, 105°– 140°E)]

where Nor represents standardization and u is JJA-mean 200-hPa zonal wind. When easterly anomalies appear around 20°N and westerly anomalies appear around 5° and 35°N, the index is positive, and the EASM is stronger.

The NEWI can capture the interannual EASM-related climate anomalies and the interdecadal variability well. Compared to previous indices, the NEWI shows a better performance in describing precipitation and air temperature variations over East Asia. It can also show distinct climate anomalous features in early and late summer. The NEWI is tightly associated with the East Asian–Pacific or the Pacific–Japan teleconnection, suggesting a possible role of internal dynamics in the EASM variability. Meanwhile, the NEWI is significantly linked to El Niño–Southern Oscillation and tropical Indian Ocean sea surface temperature anomalies. Furthermore, the NEWI is highly predictable in the ENSEMBLES models, indicating its advantage for operational prediction of the EASM. The physical mechanism of the EASM variability as represented by the NEWI is also explicit. Both warm advection anomalies of temperature by anomalous westerly winds and the advection of anomalous positive relative vorticity by northerly basic winds cause anomalous ascending motion over the mei-yu–changma–baiu rainfall area, and vice versa over the South China Sea area. Hence, this NEWI would be a good choice to study, monitor, and predict the EASM (Zhao et al,2015,J Clim).


File naming and required software

EASMi_20CR_NCEP_1851_2021.txt
EASMi: The East Asian Summer Monsoon index缩写
20CR_NCEP: 所使用的基础数据NCEP_20CR再分析资料
1851-2021: 数据起始和结束年份
EASMi_ERA_1979_2017.txt
ERA: 所使用的基础数据ERA再分析资料
1979-2017: 数据起始和结束年份


Data Citations Data citation guideline What's data citation?
Cite as:

Huang, G., Zhao, G. (2019). The East Asian summer monsoon index (1851-2021). National Tibetan Plateau Data Center, DOI: 10.11888/Meteoro.tpdc.270323. CSTR: 18406.11.Meteoro.tpdc.270323. (Download the reference: RIS | Bibtex )

Related Literatures:

1. Zhao, G.J., Huang, G., Wu, R.G., Tao, W.C., Gong, H.N., Qu, X., & Hu, K.M. (2015). A New Upper-level Circulation Index for the East Asian Summer Monsoon Variability. Journal of Climate, 28(24), 9977-9996. doi:10.1175/JCLI-D-15-0272.1( View Details | Bibtex)

Using this data, the data citation is required to be referenced and the related literatures are suggested to be cited.


Support Program

Pan-Third Pole Environment Study for a Green Silk Road-A CAS Strategic Priority A Program (No:XDA20000000)

Copyright & License

To respect the intellectual property rights, protect the rights of data authors,expand servglacials of the data center, and evaluate the application potential of data, data users should clearly indicate the source of the data and the author of the data in the research results generated by using the data (including published papers, articles, data products, and unpublished research reports, data products and other results). For re-posting (second or multiple releases) data, the author must also indicate the source of the original data.

Example of acknowledgement statement is included below: The data set is provided by National Tibetan Plateau Data Center (http://data.tpdc.ac.cn).


License: This work is licensed under an Attribution 4.0 International (CC BY 4.0)


Related Resources

No record

No record

No record

Comments

Current page automatically show English comments Show comments in all languages

Download Follow
Keywords
Geographic coverage
East: 140.00 West: 105.00
South: 2.50 North: 37.50
Details
  • Temporal resolution: Yearly
  • Spatial resolution: --
  • File size: 1 MB
  • Views: 2,656
  • Downloads: 167
  • Access: Open Access
  • Temporal coverage: 1851-06-01 To 2021-08-31
  • Updated time: 2021-11-23
Contacts
: HUANG Gang   ZHAO Guijie  

Distributor: National Tibetan Plateau Data Center

Email: data@itpcas.ac.cn

Attachments
Export metadata