Paper Harvest Report
Date range: April 15, 2026
2 top-tier papers selected out of 146 total publications
Today’s Highlights
Intensifying ocean eddies along subtropical western boundary currents are reshaping shelf-sea conditions — cooling at depth while accelerating surface warming, with implications for coastal marine extremes under climate change (Nature Climate Change). Meanwhile, a large-scale study in Nature Water shows that the world’s most widely used nitrogen fertilizer is driving extreme eutrophication of surface waters across central North America.
Table of Contents
Top-Tier Journal Papers
More eddying of subtropical western boundary currents boosts stratification and cools shelf seas
Authors: K. L. Gunn, L. M. Beal
Journal: Nature Climate Change · DOI: 10.1038/s41558-026-02599-9
Matched topics: climate change, coastal
Ocean eddies are intensifying with climate change, especially in western boundary currents. Boundary currents separate coastal seas from the open ocean, but eddies drive cross-slope fluxes that can adjust the current and change shelf-sea conditions. Here we analyse two years of mooring observations in the Agulhas Current, diagnosing eddy dynamics and fluxes. We find that eddies converge heat and salt towards the current core over time, cooling adjacent shelf seas while broadening and stratifying the current. On the inshore edge, frequent 10-km frontal instabilities dominate, pumping cold, nutrient-rich waters up onto the shelf, while farther offshore 100-km meanders move heat onshore. The result is accelerated warming at the surface, but cooling at depth. Similar tendencies are expected in all subtropical western boundary currents as eddying increases, implying that adjacent shelf and slope seas will bear more extremes in the future, even while the strength of these currents may hold steady.
World’s predominant nitrogen fertilizer induces extreme eutrophication of surface waters in central North America
Authors: Cale A. C. Gushulak, Amir M. Chegoonian, Jess Lerminiaux, Deirdre Bateson, Viraj Shah, Heather A. Sauer et al.
Journal: Nature Water · DOI: 10.1038/s44221-026-00636-7
Matched topics: surface water
Urea, the world’s predominant nitrogen fertilizer, has supported human population growth for the past 60 years, yet its effects on freshwater ecosystems are largely unknown. Here urea additions at ecologically relevant rates tripled summer phytoplankton abundance in replicate agricultural reservoirs with significant responses by most eukaryotic algae, but not cyanobacteria or their toxins. Mass budgets reveal that fertilized reservoirs did not become limited by phosphorus due to its continuous release from sediments. Further, most added nitrogen did not accumulate in reservoirs but was lost to the atmosphere, probably as NH3. Sub-continental spatial analysis shows that study reservoirs are characteristic of shallow water bodies within Canada’s largest agricultural region, where >40% of surface waters are vulnerable to degradation by urea. Similar degrees of water quality loss by urea are expected in other global agricultural regions (for example, China, India, North America) where elevated urea use interacts with phosphorus-rich surface waters to induce extreme eutrophication. Urea, the most widely used nitrogen fertilizer, has unknown impacts on freshwater ecosystems. This study demonstrates that urea additions in Canadian prairie agricultural reservoirs triple phytoplankton abundance without increasing cyanobacterial toxins, revealing considerable nitrogen loss to the atmosphere and highlighting potential global water quality degradation in phosphorus-rich agricultural regions.
Statistics
| Metric | Count |
|---|---|
| Journals searched | 11 |
| Total papers fetched | 146 |
| Passed deterministic filter | 8 |
| After LLM relevance filtering | 2 |
| Rejected (not relevant) | 6 |
Papers by journal
| Journal | Papers |
|---|---|
| Nature Climate Change | 1 |
| Nature Water | 1 |
Filtering Criteria
Topics: hydrology, hydrologic model, river, runoff, streamflow, reservoir, water management, flood, drought, seasonal, land surface model, climate change, hydropower, surface water, irrigation, earth system model, estuary, coastal, freshwater discharge, river plume, ocean biogeochemistry, marine heatwave, paleohydrology, paleoclimate, Quaternary, Holocene, Pleistocene, fluvial geomorphology, river terrace, loess, drainage network, river capture, landscape evolution, luminescence dating
Fields: engineering, environmental science, computer science, geology, geography