{
  "id": 16292967,
  "title": "In 2015, scientists released pink dye off California to mimic pollution; waves drove it nearly 8 miles a day, carrying the plume toward San Diego Bay",
  "url": "https://urgent.news/2026/10/24/in-2015-scientists-released-pink-dye-off-california-to-mimic",
  "topic": "science",
  "section": "Science",
  "published": "2026-10-24T06:48:22.000Z",
  "source": {
    "name": "Hindustan Times - World News",
    "slug": "hindustan-times-world-news",
    "url": "https://www.hindustantimes.com/world-news/us-news/in-2015-scientists-released-pink-dye-off-california-to-mimic-pollution-waves-drove-it-nearly-8-miles-a-day-carrying-the-plume-toward-san-diego-bay-101792749874787.html"
  },
  "original_language": "en",
  "account": "In 2015, a team of scientists from the Scripps Institution of Oceanography conducted an experiment off the coast of Imperial Beach, California. They released a non-toxic, bright pink fluorescent dye into the ocean to track how it moved along the coast. The goal was to simulate pollution, as it is often difficult to track once it enters the sea. The dye, which glows, allowed researchers to monitor its movement using sensors in the water and imaging equipment on an airplane.\n\nThe experiment, part of a larger project called Cross-Surfzone/Inner-shelf Dye Exchange (CSIDE), was funded by the National Science Foundation. The team released about 30 gallons of dye solution near the beach, and tracked its movement for approximately 30 hours. The leading edge of the dye crossed the coastline in roughly 11 hours, traveling north due to the incoming waves. This movement aligns with the Scripps account of the dye moving north during a strong south swell, leading toward the entrance of San Diego Bay.\n\nHowever, the movement was not straightforward. While the waves pushed the dye north, currents in the deeper water moved slowly south. The dye in the surf zone, where it was released, remained for extended periods, while dye further out was carried differently. Rip currents, which are narrow, fast streams that pull water away from the shore, played a significant role in transporting the dye from the surf zone to deeper water. The study estimates that the surf-zone water was exchanged with deeper water about every 2.3 hours.\n\nDespite some dye remaining in the deeper water, it did not stay there forever. The dye stored in deeper water drifted more slowly south than the surf zone flowed north, a process known as recirculation. This recirculation extended the plume's reach over time and created long, fading tails in the readings at points farther along the coast.\n\nThe study highlights the importance of understanding how pollution travels along the coast, as it can help improve real-time forecasts of where pollution is going for beaches in San Diego, Imperial Beach, and Coronado. However, more studies and model work are needed to validate the model's accuracy in other conditions. Despite these limitations, the experiment provided a clear view of something normally hidden and helped explain how shoreline pollution may travel.",
  "summary": "In 2015, scientists released pink dye off Southern California to mimic pollution. Waves pushed it north nearly 8 miles a day, and it thinned out fast.",
  "key_points": [
    "Scientists released pink dye off California coast in 2015 to track pollution movement.",
    "Dye traveled nearly 8 miles a day, driven by waves toward San Diego Bay.",
    "Study highlights importance of understanding pollution travel along coastlines."
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}