On May 9, 2025, a research-enhanced weather buoy was deployed at 40.50°N 69.25°W for an expected observing period of one year. Working alongside a team of engineers and technicians at the National Data Buoy Center (NDBC), Dr. Yolande Serra's (UW/CICOES) project has enhanced weather buoy 44008 with additional surface and subsurface sensors. The station, located on the New England shelf on the north side of the core Gulf Stream current in 72 meters of water, has standard measurements of wave height and period, sea surface temperature, wind speed and direction, air temperature, humidity, and surface pressure available from all NDBC operational weather buoys. This project's enhancements include a current meter at 3 meter depth, subsurface temperature, salinity, and pressure sensors distributed at depths from 5 to 55 meters, an upward looking acoustic doppler current profiler at 55 meter depth, and upward looking solar and infrared radiometers mounted on the buoy tower.

With the addition of the radiation sensors, the weather buoy now provides all the components of the surface ocean heat budget, while the subsurface temperature and salinity sensors provide information about the heat content and depth of the surface mixed layer. We can additionally learn about ocean mixing and advection of heat and water properties from the wind, wave, and current measurements. Together, the added observing capabilities provided through this pilot study could lead to better understanding and prediction of the ocean's influence on storm development impacting the northeastern US, as well as marine heatwaves, coastal circulation, and ocean eddies.

While the operational data are distributed through NDBC’s standard webpage, "enhancement" data are pulled to PMEL servers and served via a NOAA/PMEL public data access portal. This project is located about 65 nautical miles east of the US National Science Foundation Ocean Observatories Initiative (OOI) Coastal Pioneer New England Shelf Array, a 5-year research program that collected detailed ocean and air-sea interface observations of the New England shelf from 2017 to 2022, providing important context for our 1-year pilot study. The data collected by our project are aligned with the data needs of the National Weather Service (NWS), Northeastern Regional Association of Coastal Ocean Observing Systems (NERACOOS), and Mid-Atlantic Regional Association Coastal Ocean Observing System (MARACOOS), with additional potential data users within the fishing and wind energy communities.  The future of the enhanced weather buoy concept will be explored through surveys of our primary data users following the outcome of this pilot study and the ongoing needs of the US coastal communities.

The "Pilot Upgrade of NOAA NDBC Coastal Weather Buoys for Improved Monitoring of Weather and Climate", led by Dr. Yolande Serra (UW/CICOES) as a joint UW/CICOES, NOAA/NWS/NDBC, and NOAA/PMEL project, was funded by NOAA's Weather Program Office (WPO) grant number NA23OAR4590404. This project is in alignment with the Weather Forecasting and Innovation Act of 2017 (Public Law 115-25), which aims to improve NOAA's weather research through "investment on affordable and attainable advances in observational, computing, and modeling capabilities".

PI, Co-PIs and Project Affiliates:

Yolande Serra - UW/CICOES
Meghan Cronin - NOAA/PMEL
Dongxiao Zhang - NOAA/PMEL and UW/CICOES
Ian Sears - NOAA/NDBC
James Elliott - NOAA/NDBC
Nathan Anderson - NOAA/PMEL and UW/CICOES
Patrick Berk - NOAA/PMEL and UW/CICOES

Despite rapid Arctic warming, plan for more frigid spells

New research on the Arctic confirms that even as the Arctic is warming faster than the rest of the world, cold-air outbreaks from the polar region will continue across the Northern Hemisphere in the coming decades.

The big challenge now is to better understand what triggers these cold-air outbreak events and how to improve their predictability.

Much of the previous research has shown how a weakening of the stratospheric polar vortex can allow pockets of frigid air to plunge much farther south than normal. The new study, conducted by an international team including Arctic researchers from NOAA, provides additional insights as to how other influences - stalled weather systems, stretching of the stratospheric polar vortex and even events in the distant midlatitudes can influence these polar patterns.

"A better understanding of these Arctic-midlatitude linkages would improve forecasts covering periods of weeks to months, which would give communities more time to plan for adverse winter weather conditions," said co-author Muyin Wang, a scientist from the Cooperative Institute for Climate, Ocean, and Ecosystem Studies who works at NOAA’s Pacific Marine Environmental Laboratory (PMEL). "The impacts can be more significant as societies conditioned to global warming become increasingly less used to them."

The study was published in Environmental Research: Climate.

The stratospheric polar vortex is a mass of cold whirling air bounded by the jet stream that forms 10 to 30 miles above the Arctic surface in response to the large north-south temperature difference that develops during winter. Generally, the stronger the winds, the more the air inside is isolated from lower latitudes, and the colder it gets. But sometimes it can be shifted or stretched off the pole toward the United States, Europe or Asia.

"It seems really counterintuitive, but there will be plenty of ice, snow, and frigid air in the Arctic winter for decades to come, and that cold can be displaced southward into heavily populated regions by Arctic heat waves," said co-author Jennifer Francis with the Woodwell Climate Research Center.

The study, which resulted from an international workshop held in 2023 in Great Britain, provides a new analysis of recent research that offers a pathway to improved forecasts.

The authors said the stratospheric polar vortex has been relatively under-studied in previous reviews of Arctic-midlatitude climate linkages that focus predominantly on the role of changes in the tropospheric polar jet stream. They suggest that future research should focus on the complicated interactions between Arctic, midlatitude and tropical influences.

While many analyses focus on warm Arctic and cold midlatitude events, connections have also been found between unusually cold Arctic temperatures and warm winter events in midlatitudes, especially in Europe.

"Such a range of results confounds those who would like the science to offer a simple way to anticipate seasonal outlooks," said James Overland, a research oceanographer at PMEL.

One of the complicating factors occurs when a weather system stalls, creating an atmospheric block: a quasi-stationary modification of the jet-stream flow that occurs at middle and high latitudes and typically last for one to a few weeks. Blocking events are associated with persistent weather conditions in the vicinity of the block and frequently lead to extreme weather events in midlatitudes, including winter cold air outbreaks.

Tropical climatic drivers, such as the El Niño-Southern Oscillation and the Madden-Julian Oscillation, can create the conditions that lead to the establishment of these atmospheric blocks thousands of miles away.

The study authors underscored the need for research to better understand how to predict cold outbreaks in lower latitudes, which will help communities adapt to the consequences of extreme cold weather.

"The Arctic may seem irrelevant and far away to most folks, but our findings show that the profound changes there affect billions of people around the Northern Hemisphere," said lead author Edward Hanna with the University of Lincoln.

The international research team was composed of scientists from the United States, United Kingdom, Germany, Finland, South Korea, China and Japan.

"The most interesting part of the research is that the polar vortex stretching events could be an important driver of North American cold air outbreaks,” said Amy Butler, a climate researcher with the Chemical Sciences Laboratory who was not involved in the study. “It’s a novel way of looking at how the stratosphere might influence the surface climate - It’s certainly worth understanding better to improve predictability."

(Material from University of Lincoln and Woodwell Institute press releases were included in this story.)

Hanna, E., J. Francis, M. Wang, J.E. Overland, J. Cohen, D. Luo, T. Vihma, Q. Fu, R.J. Hall, R. Jaiser, S.-J. Kim, R. Köhler, L. Luu, X. Shen, I. Erner, J. Ukita, Y. Yao, K. Ye, H. Choi, and N. Skific (2024): Influence of high-latitude blocking and the northern stratospheric polar vortex on cold-air outbreaks under Arctic amplification of global warming. Environ. Res. Clim., 3(4), 042004, doi: 10.1088/2752-5295/ad93f3

The extraordinarily powerful eruption of Hunga volcano in the Tongan archipelago in the southern Pacific Ocean on January 15, 2022 blasted gas and ash 36 miles high, generating atmospheric gravity waves, two different types of destructive tsunamis, and the loudest atmospheric explosion recorded by modern instrumentation. It was one of the largest eruptions of the past 300 years.

Initially, scientists suggested the explosion occurred when magma reacted violently with water that had infiltrated the caldera of the submarine volcano, or perhaps by the collapse of the caldera itself.

Now a team of international scientists have proposed an alternative trigger mechanism, saying the trigger was the accumulation of mineral deposits within the volcano closing off exit pathways for gases from magma to escape, leading to the buildup and catastrophic release of pressure strong enough to generate shock waves that circled the planet. This theory is consistent with various lines of evidence.

Their findings are detailed in a paper that has been accepted for publication in the Journal of Volcanology and Geothermal Research.

"There are many submarine volcanoes within US territorial waters that have the potential for hazardous explosive eruptions," said Sharon Walker, an oceanographer at the NOAA's Pacific Marine Environmental Laboratory and a study co-author. "It is very important to understand all the ways that volcanoes can generate tsunamis, and to incorporate these factors into prediction and modelling capabilities so coastal communities can be prepared and resilient."

The Hunga volcano generated both extreme runup tsunamis and quite unusual and destructive meteotsunamis. The waves devastated Tonga islands locally, affected coastlines around the Pacific and were recorded around the globe, said PMEL tsunami researcher Vasily Titov. The explosive displacement of water within the caldera was one tsunami-generating mechanism. The explosion-induced pressure wave produced another kind of tsunami, often called a meteotsunami.

"There may have been other mechanisms involved as well, like landslides and pyroclastic flows off the caldera, for example,” he said. “Analysis of the tsunami data helps us better model the tsunami propagation. This new understanding will aid the development of tsunami forecast capabilities for similar events in the future."

The researchers said their new theory also accounts for the eruption's magnitude, the time sequence of the event, the massive amounts of volcanic gas that were released, the remaining volcano structure and the presence of minerals formed by gas from magma interactions with the surrounding rock (e.g., sulphate minerals) in the ash deposits.

For a submarine volcano to release enough energy through the water column to create this immense plume as well as a globally-felt atmospheric air blast and a meteotsunami, a colossal amount of force would be required, similar or even larger than that of the 1883 Krakatoa eruption.

Co-author Cornel de Ronde, a researcher with GNS Science in New Zealand, said that understanding the cause of the eruption is important for volcano monitoring and risk preparedness, not just for the Tongan archipelago but for submarine volcanoes generally.

"The eruption at Hunga has opened our eyes," de Ronde said.

The research team will be returning to the Tongan archipelago this month onboard the New Zealand Research Vessel Tangaroa to collect geological, geophysical, and water column data in and around the Hunga volcano crater to further investigate the cause of the eruption.

This story was adapted from a release issued by GNS Science.

January 15, 2022 Tonga volcano-generated tsunami propagation (YouTube)

Hurricane intensity predictions would benefit from timely, more accurate ocean temperature, salinity and wave measurements, NOAA researchers find.

On September 30, 2021, a saildrone uncrewed surface vehicle made history by intercepting the eyewall of Hurricane Sam in the northwestern tropical Atlantic, recording a viral video of what it’s like to be tossed around by 100 mile-per-hour winds and 30-foot high waves.

The Guinness Book of World Records later certified that a 126.4 mile-per-hour wind gust recorded by the bright orange 23-foot saildrone in the core of the Category 4 storm was a new world record for an uncrewed surface vehicle.

But the most long-lasting impact of Saildrone Explorer SD 1045’s trailblazing research voyage may come from the continuous readings collected by the craft’s temperature sensors. Timely, accurate upper-ocean observations like those collected during the mission could directly benefit hurricane intensity forecasts - if they can be swiftly provided to weather forecast systems, according to new research by NOAA oceanographers published in Frontiers of Marine Science.

“Sam turned out to be one of the longest and strongest hurricanes in our historical record,” said Andrew Chiodi, an oceanographer with NOAA’s Pacific Marine Environmental Laboratory (PMEL). “We were targeting the northeast eyewall and the intercept was a bulls-eye. Until now, we haven’t had a surface platform that we can steer into a hurricane while it continuously measures air-sea interactions, and transmits data in near real-time for use by numerical hurricane forecast models.”

Early and accurate forecasts of storm tracks and intensity are vital for protecting life and property from hurricane impacts. During the past decade, however, the accuracy of hurricane track predictions has substantially outpaced those for storm intensity, which is influenced by transfers of heat and momentum across the ocean surface during tropical cyclone development. Sea surface temperature has long been used as a statistical predictor of intensity.

Analysis by Chiodi and his research team found that the observations and measurements collected by the ocean robot revealed surface ocean temperatures had unexpectedly risen during the first half of the storm. These changes were not captured by satellites, profiling floats, or hurricane-hunting aircraft that provide the data used by hurricane forecast models, said co-author Greg Foltz, a NOAA oceanographer with the Atlantic Oceanic and Meteorological Laboratory.

As a result, the forecast model predicted surface waters to be cooler than they actually were.  This caused the model to underestimate the flow of heat from the ocean into the storm near the eyewall, which reduced the forecasted potential intensity of the storm.

Hardy, adaptable, and cost-effective

Enter the saildrone. Remotely piloted and powered by wind and solar energy, these rugged ocean robots can make multiple simultaneous environmental observations including wind speed, wave height, temperature, pressure and salinity in places too dangerous for people to venture. Saildrones are equipped with Global Positioning System and an onboard computer, enabling the vehicles to navigate to prescribed waypoints, autonomously adjusting for wind direction and current. Each vehicle is supervised 24/7 by operators at Saildrone Mission Control in Alameda, California.

PMEL began a partnership with Saildrone, Inc. in 2014 to adapt the uncrewed surface vehicles to collect high-quality oceanic and atmospheric observations.

In addition to the vehicles themselves, Saildrone, Inc. provides engineering expertise in vehicle design, software, electronics and operations.  PMEL provides engineering expertise on sensors, sensor sampling schemes, telemetry protocols and access to calibration equipment and facilities.

NOAA-Saildrone missions have included surveys of the U.S. west coastal waters around Alaska, basin-scale crossings from Hawaii to San Diego and San Francisco to the Equatorial Pacific, and high-latitude missions in the Bering and Chukchi Seas, with tasks ranging from tracking fish and mammals, measuring dissolved carbon dioxide, salinity, and ocean acidification, detecting and tracking oil seeps and spills, charting underwater bathymetry for safe navigation, and surveying the Arctic ice edge.

In 2019, a modified saildrone completed a 196-day, 13,500-nautical-mile journey around Antarctica, collecting oceanic and atmospheric carbon dioxide measurements with a PMEL-designed instrument in one of the most hostile seas on the planet - in winter. “The assumption was the Southern Ocean would eat the saildrone,” said PMEL’s Adrienne Sutton. “And that would be that.”

During the 2021 Atlantic hurricane season, five saildrones were deployed in selected areas of the northwestern tropical Atlantic, Caribbean, and South Atlantic Bight, their wings strengthened and reduced in height to withstand hurricanes. Saildrone SD-1045 navigated into position northeast of Puerto Rico so it could intercept Hurricane Sam on the northeast side, where winds are usually most intense. Sam was the 2021 Atlantic hurricane season’s strongest and longest-lived storm and one of the longer-lived Atlantic hurricanes since basinwide satellite monitoring began in 1966.

“The saildrone allows us to monitor conditions continuously throughout the core of a storm, where most of the energy exchange occurs,” Foltz said. “This is a good example of the unique value of the saildrone measurements for research, and potentially for improving hurricane intensity forecasts.”

Since 2021, NOAA has continued to partner with Saildrone to improve hurricane forecasts. In 2023 NOAA increased the number of saildrones tracking hurricanes from seven to 12, with data made available to the next-generation Hurricane Analysis and Forecast System.

Researchers are now using data collected by saildrones and other in-situ and remote-sensing platforms for use in improving the new forecast system. They’re also exploring adding new sensors to future saildrone missions to capture unique measurements like sea spray, which influences heat and momentum exchanges within hurricanes.

In addition to NOAA scientists, coauthors on the paper included researchers from the University of Washington, University of Hawaii, University of Miami, University of Georgia, the U.S. Naval Research Laboratory, Penn State University and the University of Santiago de Compostela in Spain.