Salinity Variation Studies

Excited to share our latest publication in JGR: Oceans, led by PhD student Yuxuan Lyu with co-authors Nathan Bindoff, Sandeep Mohapatra, Saurabh Rathore, and Helen Phillips. This study uncovers how the ocean’s salinity is amplifying under climate change, but why it doesn’t simply mirror changes in rainfall and evaporation. We find that the familiar “salty gets saltier, fresh gets fresher” pattern extends beyond the surface and into the ocean interior. But here’s the key: (1) In evaporation-dominated subtropical regions, ocean currents (horizontal advection) spread out excess salt, preventing extreme local build-up. (2) In rainfall-dominated regions, vertical mixing and diffusion push freshwater deeper into the ocean. (3) This means that surface salinity is not just a passive record of atmospheric changes. It is actively reshaped by ocean circulation, giving us a more complete picture of the global water cycle. By analyzing four decades of ocean reanalysis data, we show how atmospheric freshwater fluxes and oceanic processes interact to shape salinity patterns. These findings strengthen the use of ocean salinity as a natural tracer of climate change and help refine projections of how the global water cycle will evolve in a warming world. https://lnkd.in/gBTGiKHr

July 12, 2023 -  JACKSONVILLE, FLA - "A groundbreaking study (https://lnkd.in/ehuz8c78 ) published today in Global Change Biology reveals the critical yet severely understudied factor of salinity changes in oceans and coastlines caused by climate change. The study was co-authored by an international team of researchers, including Dr. Cliff Ross, University of North Florida biology chair/professor, and Dr. Stacey Trevathan-Tackett, UNF biology graduate program alum and research faculty member at Deakin University in Australia.  Changes in salinity, or salt content, due to climate change and land use can have potentially devastating impacts on vital coastal and estuarine ecosystems, yet this has rarely been studied until now. This new research provides valuable insights into the threats posed by anthropogenic salinity changes to marine and coastal ecosystems and outlines consequences for the health and economy of local communities in oftentimes densely populated regions. The research team looked at how climate change-related variations in rainfall as well as local man-made impacts can lead to extreme flood and drought events, affecting freshwater availability and impacting salinity in sensitive ecosystems. As sea-levels rise, saltwater inflows in coastal and low-lying areas can also cause devastating impacts. Certain groups such as microorganisms, plankton, coral, mangroves, tidal marshes, macroalgae and seagrass are most at risk and can quickly face ecosystem collapse.    The researchers warn that salinity changes are predicted to intensify alongside ocean warming, and they stress the urgency of immediately addressing these salinity challenges to safeguard marine and coastal ecosystems and biodiversity." #climatechange #salinity #sealevelrise #oceanwarming #marineecosystems #marinelife #coastalecosystems

“Groundwater salinity in California’s southwestern San Joaquin Valley”   The San Joaquin Valley is one of the most intensive oil and gas and agricultural production regions of the U.S., yet the regional groundwater salinity distribution is not particularly well defined, most notably near the western margin of the valley where salinity is highly variable. In this study, airborne electromagnetic (AEM) surveys were used to collect spatially comprehensive, high-resolution resistivity data, filling the spatial gaps between wells.  Bulk resistivity is highly sensitive to groundwater salinity due to the increased electrolytic conduction that occurs at higher TDS concentrations. Here, a salinity mapping approach representing geophysical and interpretational uncertainty was used to predict the probability of the occurrence of three salinity categories commonly used in water resource management (FRESH, total dissolved solids (TDS) < 3000 mg/L; BRACKISH, TDS 3000–10,000 mg/L; and SALINE, TDS > 10,000 mg/L). The salinity mapping identifies regions of fresh and brackish groundwater near oil fields, suggests potential gaps in groundwater monitoring, and supports improved fresh and brackish groundwater resource availability estimates. Shallow saline regions are common near historical lake beds and marsh areas, with abrupt transitions between saline and fresh/ brackish groundwater in both historical and modern hydrogeologic contexts. These results highlight that within the surveyed region, commonly between 2 to 10 % of the vertical extent above previous estimates of the depth to the 10,000 mg/L threshold are saline, and in places such as underlying the western Buena Vista Lake Bed, more than 50% of the region overlying the threshold likely contains saline groundwater.   These results highlight that spatially comprehensive salinity mapping supports more accurate groundwater availability estimates and can identify regions of fresh and brackish groundwater near areas of oil and gas production.   See Ball et al. (2026) in Journal of Hydrogeology, “Regional and local controls on groundwater salinity in California’s southwestern San Joaquin Valley, United States: Insights from airborne electromagnetic surveys”

Saline soils are expanding. By 2050, half of the world's arable land could be affected, yet we still lack a reliable way to monitor salinity from space at scale. Microwave remote sensing holds real promise as it penetrates vegetation and responds to soil dielectric properties but the missing piece has always been a dielectric model precise enough to connect salinity to satellite signals across diverse soils and conditions. This is what our new paper in Remote Sensing of Environment sets out to build. The key departure from existing approaches is going smaller (to the pore scale) rather than adding more empirical parameters to established frameworks. At high salinity, classical ion-distribution theory breaks down because it assumes point-sized ions, ignoring that real ions crowd each other out near particle surfaces. Classical relaxation models similarly fail to capture how saline solutions behave dielectrically as concentration climbs toward saturation. We replace both with physically grounded alternatives as a Poisson-Bikerman description of microscale ion distributions and a Dynamic Cole-Cole model for saline solution permittivity across the full concentration range. These feed into a four-component soil mixing scheme that separates bound water from free water as distinct dielectric phases. The distinction matters enormously. Bound water neither behaves like free water nor consistently falls below it in dielectric loss. Its response depends on a competition between ion enrichment driven by surface charge and electric-field suppression of ionic mobility. This nuance, previously overlooked, is where prior models quietly accumulated error, especially under dry and highly saline conditions. Validated against six texturally diverse soils from China's Yellow River Delta across systematic salinity-moisture gradients, the model achieves R2 of around 0.95 across 1-6 GHz on an independent test set and crucially, outperforms existing saline-soil models specifically in the imaginary permittivity term, the component most sensitive to salinity and most directly relevant to SAR backscatter. Two practical insights stand out for remote sensing applications. L-band amplifies salinity signals and offers stronger discrimination, yet C-band responds more smoothly and suits stable operational retrieval. And there is a physical ceiling! Once pore-water concentration approaches saturation and salt precipitates, the dielectric response plateaus, further increases in soil salinity change almost nothing in the microwave signal. Knowing where that ceiling sits is as important as knowing the sensitivity below it. Physics-informed modeling of saline soils isn't a refinement at the margins. In the low-moisture, high-salinity environments where salinization is most severe and monitoring is most urgent, it is the foundation everything else depends on. https://lnkd.in/d5s_EFvP

For the past 15+ years, I've heard lots of talk about the value of #interdisciplinary research. The reality is that it is uncommon, in part because it often takes more time and effort than disciplinary work. Despite these challenges, for more than a decade I have been collaborating with Daniel Alessi, a professor of hydrogeochemistry, along with many other colleagues on concerns arising from oil and gas development. We've published a number of papers over the years. Today, we had an especially proud moment when a project that started in the summer of 2018 was published in Nature Water, part of the Nature Portfolio. Led by Ashkan Zolfaghari, first a PhD student and later a postdoc, this project introduces two parameters to better assess the environmental impact of flowback and produced water (FPW): total produced salts (TPS), which accounts for both volume and salinity, and produced salts intensity, the ratio of TPS to the energy content of recovered hydrocarbons. Whereas traditional evaluations of FPW management have focused on volume and chemical additives in #hydraulicfracturing (HF) fluids, such foci neglect variations in FPW volumetric production and #salinity. Analysing a database of over 620,000 HF and conventional wells in North America, we found that more than 355 billion tonnes of salts were produced from 2005 to 2019, with HF wells contributing over 85%. Projections indicate that more than 1.5 trillion tonnes of salts will be produced by wells drilled between 2019 and 2050, predominantly from HF wells. We propose that TPS and produced salts intensity are crucial for assessing environmental risks, treatment costs and resource extraction potential, providing valuable metrics for regulators and planners. https://lnkd.in/dNErzKwH

Delighted to share our new paper led by my PhD student Ahmed Ziaur Rahman on "soil and water salinity dynamics in coastal Bangladesh" published in Scientific Reports. Using 19 years of field monitoring data from highly salinity-prone SW coastal Bangladesh, we show very strong seasonal variations (up to two orders of magnitude!) in soil and river-water salinity, underscoring the dominant role of seasonal temperature and rainfall. Cyclone impacts on salinity are generally short-lived, with pre-monsoon cyclones exerting stronger effects than post-monsoon events. We also find positive associations between soil and river-water salinity and sea-surface salinity, while seasonal sea-level rise during the monsoon is inversely related to salinity due to high freshwater fluxes. Notably, no consistent long-term trend (2004-2022) emerges across the full record, although dry-season soil salinity has increased since the mid-2010s. Overall, the results show that soil and surface-water salinity dynamics are governed by multiple interacting drivers, rather than climate change or rising sea levels alone, highlighting the need for nuanced, context-specific interpretations of salinity change in coastal Bangladesh. #soil #water #salinity #salinisation #Bangladesh #delta #sealevelrise https://lnkd.in/eeHWrjJw

Congratulations to the research teams at the New Mexico Produced Water Research Consortium and Texas Pacific Land Corporation (TPL) on their latest study published by Elsevier. They used various treated produced waters to evaluate the effects on the soil microbiome, soil-plant interactions, and the accumulation of organics in soil matrices characteristic of the #Permian Basin. These data indicate to me that we can match treated water quality to specific soils and specific crops for agricultural optimization. Punhasa Senanayake Yanyan Zhang Thiloka Edirisooriya Adrianne Lopez Billings Pei Xu Huiyao Wang Produced Water Society #water #energy #environment #agriculture "The reuse of treated produced water (tPW) for irrigation is increasingly attractive in water-scarce regions, yet its impacts on plant performance, soil health, ion dynamics, and microbial communities are not fully explored. This study evaluated plant growth and soil response over a nine-month greenhouse experiment in the Permian Basin (Texas), using clay-rich and sandy-loam soils irrigated with tPW at total dissolved solids (TDS) concentrations of 500, 1000, and 1500 mg/L, alongside a desalinated-groundwater as the control. Soil quality index analysis showed that tPW at ≤1000 mg/L maintained and occasionally improved soil health relative to the control, whereas 1500 mg/L caused soil degradation by disrupting ion balance, increasing salinity stress, and shifting microbial communities. Moderate-salinity tPW preserved a balanced ion profile that supported nutrient retention, microbial activity, and soil structure; in contrast, higher TDS led to ion accumulation, salinization, nutrient depletion, and osmotic stress, which diminished water retention and fertility. Alfalfa irrigated with 1000 mg/L tPW produced forage with higher crude protein, lower fiber fractions, and improved digestibility, affirming its suitability for saline forage systems. Microbial analysis illustrated minimal impact on bacterial and fungal diversity at ≤1000 mg/L TDS, whereas 1500 mg/L TDS alters fungal composition in loamy soils, reducing richness and increasing pathogenic fungi in deeper layers. These results underscore the promise of tPW for sustainable irrigation, provided that salinity levels, ion accumulation, and microbial responses are carefully managed to safeguard soil health, optimize nutrient cycling, and sustain long-term productivity." https://lnkd.in/gedJRe-w

#FluidInclusion Salinity: Can We Rely on It for #FormationEvaluation? Have you ever faced challenges in exploration where no clear reference for formation water salinity was available to evaluate water saturation from petrophysics or well-log interpretation? Imagine this: you haven’t reached fluid contacts, and your analogue data seems uncertain. Could fluid inclusion salinity be the key to unlocking valuable insights? Using fluid inclusion salinity to estimate water salinity for water saturation interpretation in well-log analysis is a nuanced approach. While it can provide valuable insights, its reliability depends on understanding both its strengths and limitations. One of my previous case studies, presented at the EAGE Annual Symposium 2023 in Austria, explored this very question. You can check out the full article here: https://lnkd.in/d5kaPrQK So, what makes fluid inclusion salinity worth considering? #Pros: - Snapshot of Paleofluids: Fluid inclusions capture the salinity of fluids trapped during mineral formation, offering insights into paleo-fluid compositions. - Understanding Fluid Evolution: For reservoirs where water salinity has evolved due to mixing or migration, inclusions help reconstruct original salinity. - Supplementing Analogue or Formation Water Data: Fluid inclusion data can refine or corroborate salinity estimates when modern data is limited. However, as with any method, there are #limitations and #challenges to keep in mind: - Temporal Mismatch: Fluid inclusions reflect past conditions, which may not align with present-day reservoir salinity due to processes like dilution or mixing. - Spatial Variability: Inclusions record localized salinity, which might not represent the reservoir-scale average. - Interpretation Complexity: Techniques like microthermometry require precise calibration, and errors can propagate. - Chemical Evolution: Over time, trapped brines may undergo alterations that differ from current formation water chemistry. - Representative Sampling: Not all inclusions contain water; some may hold hydrocarbons or other fluids, complicating salinity estimates. What do you think? Have you used fluid inclusion salinity in your evaluations? How did it perform compared to other methods? Let’s start a conversation—share your thoughts and experiences below! 😊 #Petrophysics #discussion #geoscience #OilandGas #reservoircharacterization #petrography

🧂 Can tiny gas molecules help crops thrive in salty soils? 🌱 Salinity stress affects millions of hectares of farmland worldwide, reducing crop yields & damaging soil health. 🧪 In this study, researchers explored how hydrogen sulfide (H₂S) & nitric oxide (NO) help cucumbers tolerate salt stress. 💧 Sodium hydrogen sulfide (NaHS) was used as the H₂S donor, while sodium nitroprusside (SNP) served as the NO donor. 🔬 Inhibitors L-NAME & cPTIO were also applied to confirm NO's specific role under salinity. 📈 Treatments with NaHS & SNP improved cucumber growth under salt stress — increasing fresh & dry weight, plant height & chlorophyll content. 🧬 These treatments also raised internal levels of H₂S & NO, which activated key antioxidant enzymes like SOD, CAT, APX, GR, GPX & GSTs. 🛡️ This response reduced oxidative damage by lowering reactive oxygen species (ROS) & lipid peroxidation. 🌿 The combined application of H₂S & NO donors helped plants grow better even under salt stress, offering a low-cost, effective strategy for stress mitigation. 🌾 These findings highlight a promising approach to maintaining crop productivity in saline environments. 🌍 Using H₂S & NO donors may help sustain agriculture in areas threatened by rising soil salinity — a major global challenge for food security. https://bit.ly/4mCHeg8

I am happy to share our recent publication on npj Clean Water, led by my PhD student Shinyun Park who just successfully defended her PhD dissertation. This work elucidates the role of salinity in regulating gypsum scaling in reverse osmosis and nanofiltration. The key findings of this work include: 1. An increase of salinity reduces the extent of gypsum scaling by lowering ion activity and consequently the saturation index, but the energy barrier and kinetic pre-factor of nucleation remain unchanged. 2. Altering membrane transport properties such as water and salt permeances changes gypsum scaling potential of membranes by regulating the accumulation of both scalants and background salts near the membrane surface. This work has important implications to the applications of reverse osmosis and nanofiltration to desalinating feedwaters with various salinities, particularly considering their increasing use in the treatment of high-salinity brines. This work is open access and supported by National Science Foundation (NSF) Paper link: https://lnkd.in/gBRcbXAr