Pacific Blob — LLMpedia

Pacific Blob
Name	Pacific Blob
Caption	Warm sea surface anomaly in the northeastern Pacific
Location	North Pacific Ocean
First reported	2013–2015
Type	Marine heatwave / oceanic anomaly
Affected areas	Bering Sea, Gulf of Alaska, California Current System

Contents

Pacific Blob

The Pacific Blob was a large, persistent marine heatwave in the northeastern Pacific Ocean observed primarily during 2013–2016 that produced unusually warm sea surface temperature anomalies, altered marine ecosystems, and influenced weather patterns across North America, East Asia, and adjacent marine regions. It attracted attention from institutions such as the National Oceanic and Atmospheric Administration, Scripps Institution of Oceanography, and the University of Washington, and intersected with events including the 2014–16 El Niño event and shifts in the Pacific Decadal Oscillation. Researchers from organizations like the National Aeronautics and Space Administration and Joint Institute for the Study of the Atmosphere and Ocean applied satellite, shipboard, and model data to document its evolution and impacts.

Overview

The anomaly formed as an extensive pool of elevated sea surface temperatures off the coast of North America stretching from the Gulf of Alaska to the California Current and into the Bering Sea. Observations by NOAA and teams at Scripps Institution of Oceanography mapped surface and subsurface warming, while analyses by the National Center for Atmospheric Research and the Pacific Marine Environmental Laboratory characterized it as one of several notable Northeast Pacific marine heatwaves in the 21st century. The phenomenon coincided with altered distributions of species studied by institutes such as the Alaska Fisheries Science Center and the Northwest Fisheries Science Center and was evaluated in the context of climate indices like the North Pacific Gyre Oscillation and the Arctic Oscillation.

Multiple studies implicate a combination of persistent atmospheric circulation anomalies and ocean dynamics. Strong, stationary ridging in the mid-latitude jet linked to the Aleutian Low displacement and influences from the Arctic Oscillation reduced heat loss to the atmosphere, as documented by researchers at the Geophysical Fluid Dynamics Laboratory and University of California, San Diego. Reduced wind-driven mixing along the California Current System and altered upwelling tied to changes in the Pacific Decadal Oscillation and the North Pacific Current contributed to anomalous stratification. Subsurface advection and eddy dynamics involving features like mesoscale eddies, tracked using data from Argo floats and the Global Drifter Program, redistributed heat, while coupled atmosphere–ocean models developed at NOAA Geophysical Fluid Dynamics Laboratory and European Centre for Medium-Range Weather Forecasts simulated feedbacks with the 2015–16 El Niño–Southern Oscillation.

The warm anomaly altered marine food webs, affecting commercial and subsistence fisheries managed by agencies such as the North Pacific Fishery Management Council and the Pacific Fishery Management Council. Shifts in species distributions included northward movements of pelagic predators documented by researchers at the Monterey Bay Aquarium Research Institute and altered spawning of species monitored by the Alaska Department of Fish and Game. Events linked to the anomaly included mass mortalities of marine mammals and seabirds noted by the Marine Mammal Laboratory and the U.S. Fish and Wildlife Service, and harmful algal blooms impacting fisheries tracked by the California Department of Fish and Wildlife. Studies published by teams at University of British Columbia, Oregon State University, and University of Alaska Fairbanks recorded impacts on plankton communities, salmon returns, and commercially important species such as Pacific cod, walleye pollock, and Dungeness crab.

Atmospheric teleconnections associated with the anomaly influenced temperature and precipitation patterns across western North America and into East Asia, with documented links to persistent drought conditions evaluated by the U.S. Drought Monitor and changes in storm tracks analyzed by the National Weather Service. Enhanced coastal warming affected sea-ice extent in the Bering Sea and modulated winter storm frequency impacting infrastructure in regions served by agencies like the Federal Emergency Management Agency. Climate scientists at the Intergovernmental Panel on Climate Change and the Woods Hole Oceanographic Institution have assessed how decadal variability, anthropogenic warming assessed by NASA, and modes such as the Pacific Decadal Oscillation may interact to alter the likelihood of similar events.

Detection relied on multi-platform observations including satellite radiometers operated by NOAA and European Space Agency missions, in situ profiles from Argo and shipboard CTD casts conducted by institutions like the Woods Hole Oceanographic Institution and the Monterey Bay Aquarium Research Institute, and surface drifters from the Global Drifter Program. Operational monitoring used products from NOAA National Centers for Environmental Information and modeling systems at the European Centre for Medium-Range Weather Forecasts and NOAA Geophysical Fluid Dynamics Laboratory. Predictive research employed coupled models from the Predictive Ocean Atmosphere Model for Australia and ensemble hindcasts used by the Met Office and National Center for Atmospheric Research to explore predictability and attribution.

Resource managers, coastal communities, and indigenous groups engaged with agencies including the North Pacific Fishery Management Council, Pacific Fishery Management Council, and state departments such as the California Natural Resources Agency to adapt fisheries regulations, monitoring, and emergency responses. Economic assessments by researchers at University of Washington and University of California, Santa Cruz quantified impacts on commercial landings and recreational fisheries, while public health agencies like Centers for Disease Control and Prevention coordinated responses to seafood safety risks from algal toxins. Policy discussions in forums such as the United Nations Framework Convention on Climate Change and regional bodies like the Pacific Islands Forum examined resilience strategies, and collaborative monitoring initiatives involved universities, tribal governments, and federal laboratories.

Category:Oceanography Category:Climate events Category:Marine heat waves