Water exchange and transport pathways in estuary-shelf region of Pearl River Estuary under multiple forcings

Cui，Lingbo1; Cai，Zhongya1,2; Liu，Zhiqiang3

2023-09-01

10.1016/j.csr.2023.105099

Continental Shelf Research   Impact Factor & Quartile

0278-4343

1873-6955

Using the Pearl River Estuary (PRE) as an example, the exposure time (θ‾) was calculated to investigate the dominant processes of three-dimensional water exchanges in the estuarine-shelf system and explore the underlying transport pathway. The θ‾, which quantifies the time of water stayed in a defined region, shows clear seasonality under the joint controls from river discharge, tides and wind forcing. It has the lowest domain-average value (∼6 days) in the early summer, then along with weakening of river discharge, it increases to the peak (∼13 days) at the beginning of the fall and remains relatively high during following fall and winter. In contrast, the vertical difference of θ‾ in the water column shows the opposite temporal variability. Spatially, θ‾ increased from the lower to the upper estuary, and in response to the gravitational circulation of surface seaward transport and the bottom intrusion, a larger θ‾ appeared in the bottom layer of water column. Numerical experiments show river discharge predominantly determined the θ‾ compared to the modulation from tides and wind. Based on the water exchange timescale in different subdomains, the transport pathway inside the estuary is controlled by river discharge and tides, which impose a net effect on weakening onshore transport. Outsides the estuary, the wind-driven shelf current modulates the remote influences from the regions far away from the PRE. The spatial structure and temporal variabilities of water exchange identified in this study help to utilize the water exchange capability and realize substance renewal in estuary-shelf regions.

Circulation connectivity Exposure time Pearl river estuary Transport pathway Water exchange

SCI

English

Corresponding

Technology Development[0093/2020/A2];Science, Technology and Innovation Commission of Shenzhen Municipality[20220815093611001];National Natural Science Foundation of China[42276004];Science, Technology and Innovation Commission of Shenzhen Municipality[JCYJ20210324105401004];Technology Development[SKL-IOTSC-2021-2023];

Oceanography

Oceanography

WOS:001062924500001

PERGAMON-ELSEVIER SCIENCE LTD

PLANT & ANIMAL SCIENCE

2-s2.0-85168538831

Scopus

1.State Key Laboratory of Internet of Things for Smart City and Department of Ocean Science and Technology,University of Macau,Macao
2.Center for Ocean Research in Hong Kong and Macau (CORE),Hong Kong
3.Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen,China

Cui，Lingbo,Cai，Zhongya,Liu，Zhiqiang. Water exchange and transport pathways in estuary-shelf region of Pearl River Estuary under multiple forcings[J]. Continental Shelf Research,2023,266.

Cui，Lingbo,Cai，Zhongya,&Liu，Zhiqiang.(2023).Water exchange and transport pathways in estuary-shelf region of Pearl River Estuary under multiple forcings.Continental Shelf Research,266.

Cui，Lingbo,et al."Water exchange and transport pathways in estuary-shelf region of Pearl River Estuary under multiple forcings".Continental Shelf Research 266(2023).