Spatial-Temporal Regularities of Hydrooptical Characteristics of the Ob River

• Published in: Izvestiya of Altai State University
• Main Authors: Акулова, Ольга Борисовна, Букатый , Владимир Иванович, Кириллов , Владимир Викторович
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: Izvestiya of Altai State University 2023
• Subjects: spectral water transparency; spectral coefficients of attenuation; absorption and scattering of light; transparency; physical model; yellow substance; suspension; chlorophyll; спектральная прозрачность воды; спектральные показатели ослабления; поглощения и рассеяния света; прозрачность; физическая модель; желтое вещество; взвесь; хлорофилл; ob river
• Online Access: http://izvestiya.asu.ru/article/view/%282023%294-02; https://doi.org/10.14258/izvasu(2023)4-02

Field studies conducted in spring (March 26 — April 9, 2022) and summer (June 5-16, 2022) in the Ob River mouth region at the three hydromorphological stations „Kazym-Mys“, „Azovy“, and „Salemal“ (YaNAO) to obtain new data on the hydrooptical characteristics of water in the Lower Ob river. Also, the trophic status and ecological state of the Lower Ob river region were assessed. The greatly varying light attenuation coefficient ε(λ) was calculated at the four characteristic wavelengths of 430, 450, 550, and 670 nm, respectively. It ranges from 9.3 m-1 to 22.1 m-1 during the winter low water (freeze-up) period and from 7.3 m-1 to 33.0 m-1 during the open water (high water) period. The calculated relative spectral contributions of major optically active components of water (pure water, suspension, yellow substance, chlorophyll) to ε(λ) suggest that suspension and yellow substance make up the maximal contribution at different horizons. Additionally, the calculated coefficient of light absorption by yellow substance кys(λ) varies within the ranges from 5.5 m-1 to 9.9 m-1 (spring) and from 3.1 m-1 to 17.0 m-1 (summer), respectively. The relative transparency was measured using the Secchi disc. The concentrations of yellow substance and major photosynthetic pigments — chlorophylls a, b, c, and carotenoids — were estimated alongside. The obtained results could be useful for environmental monitoring and predicting the dynamics of aquatic ecosystems in the region under climate change and increased anthropogenic pressure caused by the use of natural resources. В результате экспедиционных исследований, проведенных весной (26 марта — 9 апреля 2022 г.) и летом (5-16 июня 2022 г.) в устьевом участке реки Обь на трех гидроморфологических створах «Казым-Мыс», «Азовы» и «Салемал» (ЯНАО) получены новые данные по гидрооптическим характеристикам воды, дана оценка трофического статуса и экологического состояния Нижней Оби. Рассчитаны значения показателя ослабления света ε(λ) (на четырех характерных длинах волн — 430, 450, 550 и 670 ...