Particle size distributions and organic-inorganic compositions of suspended particulate matters around the Bohai Strait

Abstract

Laser in situ scattering and transmissometry (LISST) significantly improves our ability to assess particle size distribution (PSD) in seawater, while wide-ranging measurements of the organic-inorganic compositions of suspended particulate matters (SPM) are still difficult by using traditional methods such as microscopy. In this study, PSD properties and SPM compositions around the Bohai Strait (China) were investigated based on the measurements by LISST in combination with hydro-biological parameters collected from a field survey in summer 2014. Four typical PSD shapes were found in the region, namely right-peak, left-peak, double-peak and negative-skew shapes. The double-peak and negative-skew shapes may interconvert into each other along with strong hydrodynamic variation. In the upper layer of the Bohai Sea, organic particles were in the majority, with inorganic particles rarely observed. In the bottom layer, SPM were the mixture of organic and inorganic matters. LISST provided valuable baseline information on size-resolved organic-inorganic compositions of SPM: the size of organic particles mainly ranged from 4 to 20 µm and 40 to 100 µm, while most SPM ranging from 20 to 40 µm were composed of inorganic sediment.

Distributions, sources, and air-sea fluxes of nitrous oxide in Bohai Bay, China

“…Zhu et al (2018) found that SPM in Hangzhou Bay is predominantly composed of fine and medium silt, the grain size of over 90% of the SPM is less than 20 mm and CND was found to occur on the SPM. The particle size of 4-20 mm also dominated the SPM in Yellow estuary and adjacent area (Wang et al, 2017). Hence, we suspect that the CND may happen in these regions and drive N 2 O production.…”

“…The average concentration of SPM in BHB has been reported to be 45.5 mg L -1 (Qin and Li, 1982), with higher concentrations of SPM found in coastal regions and the Yellow River estuary (Cui et al, 2009). Moreover, the particle size of SPM in BHB is in the range of 4-250 μm and the average particle size is 44 μm (Wang et al, 2017). In addition, nirk and nirS genes, which code nitrite reductases in denitrification, were detected by real-time quantitative PCR in the water column of BHB, indicating that both of them played important roles during the denitrification in the water column in BHB (Wang et al, 2019).…”

CNN-based inversion of chlorophyll-a in the Bohai Sea with spatio-temporal variation characterization of driving forces

“…Zheng Xiaoshen [1] indicated that the YOC algorithm of GOCI data has higher retrieval accuracy in Bohai Bay than other retrieval algorithms. Zhang Xue [2] established the chlorophyll-a concentration inversion model by using the OC3 algorithm, blue-green band ratio method, and near-red-red band ratio method. He Yuting [3] proposed a physical-based method to retrieve spatial spectral depth fusion network (PSSDFN) by Chl-a to improve the estimation accuracy of Chl-a in coastal waters in large and medium-sized oceans.…”