Impact of climatic factors on eutrophication in the World's largest lake Zohra Mozafari, Roohollah Noori, Sayed M. Bateni, Changhyun Jun, Dongkyun Kim, Mohammad Javad Saravani, Danial Naderian, Seyed Mostafa Siadatmousavi, Hossein Afzalimehr, Jafar Azizpour, Masoud Sadrinasab, Majid Hosseinzadeh, Peiman Kianmehr, Soroush Abolfathi Ecological Indicators, 2025 • We explore impact of climatic factors on eutrophication in the world’s largest lake. • Data from MODIS-Aqua and the ERA5 model, spanning 2003 to 2021, were used. • We used the GAM to understand dynamics of Chl- a in response to the changing climate. • Photosynthetically active radiation dominantly impacted Chl- a changes in the lake. Climatic and anthropogenic factors both contribute to lake eutrophication. However, the influence of climatic factors, particularly in large, deep, and transboundary lakes, remains poorly understood due to technical challenges, data scarcity, and geopolitical constraints. This is especially true for the Caspian Sea, the world’s largest lake, where its unique continental climate further complicates efforts to quantify the climate contribution to eutrophication. This study leverages extensive datasets from MODIS-Aqua and the ERA5, spanning 2003 to 2021, to develop a generalized additive model (GAM) aimed at investigating the impact of climatic factors on chlorophyll- a (Chl- a ) concentrations in the Caspian Sea. Given the sea’s distinct continental climate, complex morphometric characteristics, and significant spatial variability in Chl- a , the basin was divided into 14 subzones to better capture regional responses of Chl- a to climatic changes. The GAM, trained to predict Chl- a , demonstrated acceptable performance (correlation coefficient > 0.5) in 12 of the 14 subzones. Results indicate the predominant influence of photosynthetically active radiation on Chl- a changes in nine subzones, particularly in the southern Caspian Sea. This parameter is critical for regulating light availability for phytoplankton productivity. Sea surface temperature emerged as the second most influential driver of Chl- a levels, likely due to its role in controlling thermal stratification and upwelling, which stimulate phytoplankton growth. Precipitation, by contrast, was found to be the least significant driver of Chl- a levels during the study period. By elucidating the relationships between climatic drivers and Chl- a levels, this study provides a comprehensive understanding of the complex dynamics of eutrophication under changing climate conditions in the Caspian Sea.
Thermal stratification and mixing of dam reservoirs in Iran Roohollah Noori, Mojtaba Noury, Maryam Khalilzadeh Poshtegal, Masoud Sadrinasab, Mehran Mahdian, Rabin Bhattarai, Mohammad Moradi, Soroush Abolfathi Watershed Ecology and the Environment, 2024 Although numerical water quality models offer valuable insights into thermal stratification (TSn) and mixing dynamics in lakes, they are often resource and time consuming, limiting their applications for investigating a large number of lakes over a wide geographical area. An alternative approach is using well-known thermal classification systems, which require minimum data to provide acceptable information on TSn and mixing patterns in lakes. This study investigates the TSn and mixing regimes in 198 dam reservoirs located in Iran, using Lewis’s method for analysis. The results highlight that all 198 investigated reservoirs in Iran can be represented by six out of eight possible thermal classifications. The majority of the northeastern reservoirs are categorized as “warm monomictic”. For the reservoirs located in the north and northwest regions, all six thermal classes are observed. However, in the southern part of Iran, only the reservoirs of “continuous warm polymictic”, “warm monomictic”, and “discontinuous cold polymictic” types are located. Our findings reveal that 35.4%, 21.2%, 17.2%, 13.1%, 6.6%, and 5.6% of the investigated reservoirs were classified as “warm monomictic”, “discontinuous cold polymictic”, “continuous cold polymictic”, “dimictic”, “discontinuous warm polymictic”, and “continuous warm polymictic”, respectively. Our results can provide authorities with initial insights for further in-depth studies and decision-making into water quality management in Iran and enhancement strategies for the reservoirs in the country.
The use of radar sensors to track marine pollution, the studied area: Iran's Majid Hosseini Hamid, Mehrnaz Farzin Gohar, Masoud Sadri Nasab, Behzad Layeghi Nivar, 2023 Based on theory, this research investigated the relationship between the penetration depth of electromagnetic waves and the conductivity of sea water based on daily parameters of temperature and salinity in Caspian Sea with low salinity and Oman Sea with high salinity. The data was received from the oceanographic center over a period of one year and the values are calculated daily and the results show that the wave range is more sensitive to salinity. The range decreases with the increase of the frequency, so that at the frequency of 1000 khz, the range for the Caspian Sea and Oman reached about 2 and 5 cm, respectively. The range in the low frequency of 100 Hz has increased significantly and its value for the Caspian Sea is 1.51 m in March (T=11.76 C0, P=7.59psu) and for the Oman Sea it is 16.22 m in January (T=22 C0 , P=36.5 psu) was obtained. Also, the sensitivity of wave range with temperature in the Caspian Sea is more than that of the Oman Sea. This amount of range was seen at minimum and maximum temperatures of 9.74 and 24.30 degrees Celsius for the Caspian Sea, respectively 34 and 45.2 meters, and for the Oman Sea at temperatures of 22 and 32.2 degrees Celsius equal to 19.57 and 22 meters. The penetration depth of radar waves in the Caspian Sea can be three times higher than in the Oman Sea due to its low salinity. Since the range decreases with the increase in salinity, therefore, taking into account the salinity of the effluent of desalination facilities in the range of 74.8psu, the range of waves with a frequency of 100Hz has decreased sharply from 19.7m to 4m, which can be the cause of its tracking in the sea.
Optimization of the modeled surface temperature by assimilation of SST data over the Persian Gulf Indian Journal of Geo Marine Sciences, 2018
Modeling of turbulent wake of surface vessel and measuring its induced magnetic field Indian Journal of Geo Marine Sciences, 2018
Modeling the physical properties of wave generated by turbulent wake of submarine in the Persian gulf and the gulf of Oman Indian Journal of Geo Marine Sciences, 2018
Spectral analysis of wind waves using field data in Strait of Hormuz Indian Journal of Geo Marine Sciences, 2018
Three-dimensional numerical modeling study of thermal pollution and its effect on dissolved oxygen and chlorophyll Indian Journal of Geo Marine Sciences, 2016
Tidal constituents in the Persian Gulf, Gulf of Oman and Arabian Sea: A numerical study Indian Journal of Geo Marine Sciences, 2016
Internal wave generation in the Gulf of Oman (Outflow of Persian Gulf) Indian Journal of Geo Marine Sciences, 2015
Investigation of the effect of outflow intrusion on acoustical signal fluctuations in laboratory Journal of the Earth and Space Physics, 2013
Phylogenic characterization of lipase producing Bacillus strains isolated from Persian Gulf sediments Australian Journal of Basic and Applied Sciences, 2011
Phylogenic characterization of lipase producing Bacillus strains isolated from Persian Gulf sediments Australian Journal of Basic and Applied Sciences, 2011
