Lidar-Observed Diel Vertical Variations of Inland Chlorophyll a Concentration

Year: 2024

Type: article

Abstract: The diel vertical variations of chlorophyll a (Chl-a) concentration are thought of primarily as an external manifestation of regulating phytoplankton’s biomass, which is essential for dynamically estimating the biogeochemical cycle in inland waters. However, information on these variations is limited due to insufficient measurements. Undersampled observations lead to delayed responses in phytoplankton assessment, impacting accurate evaluations of carbon export and water quality in dynamic inland waters. Here, we report the first lidar-observed diel vertical variations of inland Chl-a concentration. Strong agreement with r2 of 0.83 and a root mean square relative difference (RMSRD) of 9.0% between the lidar-retrieved and in situ measured Chl-a concentration verified the feasibility of the Mie–fluorescence–Raman lidar (MFRL). An experiment conducted at a fixed observatory demonstrated the lidar-observed diel Chl-a concentration variations. The results showed that diel variations of Chl-a and the formation of subsurface phytoplankton layers were driven by light availability and variations in water temperature. Furthermore, the facilitation from solar radiation-regulated water temperature on the phytoplankton growth rate was revealed by the high correlation between water temperature and Chl-a concentration anomalies. Lidar technology is expected to provide new insights into continuous three-dimension observations and be of great importance in dynamic inland water ecosystems.

Source: Remote Sensing

DOI: 10.3390/rs16193579

Authors: Hongkai Zhao, Yudi Zhou, Qiuling Gu, Yicai Han, Hongda Wu, Peituo Xu, Lei Lin, Weige Lv, Lan Wu, Lingyun Wu, Chengchong Jiang, Yang Chen, Mingzhu Yuan, Wenbo Sun, Chong Liu, Dong Liu

Institution: Zhejiang University

Language: English

Topic: Aquatic Ecosystems and Phytoplankton Dynamics

Subfield: Environmental Chemistry

Field: Environmental Science

Domain: Physical Sciences

SDGs: Clean water and sanitation, Life below water, Climate action

Open Access status: gold

Estimated APC paid: $3,069

Funders: National Natural Science Foundation of China, National Key Research and Development Program of China, Fundamental Research Funds for the Central Universities

OpenAlex ID: W4402884822