Zhengyao Lu
Forskare
Response of heterogeneous rainfall variability in East Asia to Hadley circulation reorganization during the late Quaternary
Författare
Summary, in English
The Quaternary East Asian summer rainfall evolution reconstructed with the Chinese speleothem δ18O records shows the consistency throughout the region of East Asia, and has long been considered equivalent to the monsoon intensity. Its variation and teleconnection with global climate were usually interpreted by the meridional shift of the intertropical convergence zone (ITCZ). However, many other proxy records, climate simulations and meteorological observations suggest the inconsistent rainfall patterns in the different regions of East Asia on multi-timescales. Such spatial heterogeneity in Quaternary East Asian summer rainfall indicates that the hydroclimate in this region is not fully paced by the migration of the ITCZ. Here, we report a sediment record of rainfall evolution during the last 400 ka in the northern East China Sea, and this record, in combination with a transient climate model simulation, indicates an out-of-phase relationship between rainfall over middle-southeastern East Asia and northern and southwestern East Asia on the precession band, with high boreal summer insolation corresponding to the increased rainfall intensity in the northern and southwestern East Asia, however, decreased rainfall intensity in the middle East Asia. We attribute this regional heterogeneity in East Asian rainfall to the reorganization of the Hadley circulation, including shifts in the ascending branch (ITCZ) and descending branch (subtropical westerly jet), in response to changes in the hemispheric meridional temperature gradient. Our results highlight the crucial role of the Hadley circulation in the East Asian hydroclimate and have important implications for future climate projections.
Avdelning/ar
- Institutionen för naturgeografi och ekosystemvetenskap
- MERGE: ModElling the Regional and Global Earth system
Publiceringsår
2020-11-01
Språk
Engelska
Publikation/Tidskrift/Serie
Quaternary Science Reviews
Volym
247
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Climate Research
Nyckelord
- East Asian rainfall
- East China Sea
- Grain size
- ITCZ
- Sediment flux
- Subtropical westerly jet
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0277-3791