Author: AOML Communications

Infographic showing vertical wind shear in a hurricane. Image Credit: NOAA.

Research Explores Impact of Wind Shear Direction on Tropical Cyclone Intensity

The amount of wind shear, i.e., the change of the wind with height, is one of the most commonly used predictors of tropical cyclone intensity change, with large amounts of wind shear generally being unfavorable for intensification. Regardless of the direction of the wind shear, tropical cyclones in the North Atlantic basin usually have warm, moist air from the environment near the sea surface on their east side (solid red arrows in the images) and cool, dry air from the environment on their west side (solid blue arrows in images).

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Revisiting the Recharge and Discharge Processes for Different Flavors of El Niño

Chakravorty, S., Perez, R. C., Gnanaseelan, C., & Anderson, B. T. (2021). Revisiting the recharge and discharge processes for different flavors of El Niño. Journal of Geophysical Research: Oceans, 126(11), e2020JC017075.

Plain Language Summary: The El Niño-Southern Oscillation (ENSO) is the largest source of year-to-year climate variability. ENSO has a pronounced influence on regional and global circulation and precipitation patterns and thus has considerable worldwide socio-economical impacts. El Niño, the warm phase of ENSO, exhibits modulation in the longitudinal location of its maximum warming, creating what is referred to as ENSO diversity. For conventional El Niño events, maximum surface warming is located in the eastern equatorial Pacific, for which subsurface warming along the tropical Pacific has proven to serve as a predictor several months in advance. Previous studies disagree on whether this subsurface warming is similarly essential for El Niño events that have peak surface warming in the central Pacific. The authors developed an improved method for identifying these two types of El Niño in an ocean reanalysis product. Using this improved method, they found no clear evidence of a subsurface warming precursor for the central Pacific El Niño events along the equator. This lack of a tropical subsurface precursor limits our ability to predict these types of El Niño events.

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Coral persistence despite extreme periodic pH fluctuations at a volcanically acidified Caribbean reef

Enochs, I. C., Formel, N., Manzello, D., Morris, J., Mayfield, A. B., Boyd, A., … & Hendee, J. (2020). Coral persistence despite extreme periodic pH fluctuations at a volcanically acidified Caribbean reef. Coral Reefs, 39(3), 523-528.

Abstract: Naturally acidified environments, such as those caused by volcanic CO2 venting, reveal how complex coral reef ecosystems may respond to future ocean acidification conditions. Few of these sites have been described worldwide, and only a single such site is known from the Caribbean. Herein, we have characterized an area of volcanic acidification at Mayreau Island, St. Vincent and the Grenadines. Despite localized CO2 enrichment and gas venting, the surrounding area has high hard and soft coral cover, as well as extensive carbonate frameworks. Twice daily extremes in acidification, in some cases leading to undersaturation of aragonite, are correlated with tidal fluctuations and are likely related to water flow. Corals persisting despite this periodic acidification can provide insights into mechanisms of resilience and the importance of natural pH variability on coral reefs.

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AOML Scientists Play Critical Role in Success of NOAA’s Hurricane Field Program

The active 2021 Atlantic hurricane season ended on November 30, producing 21 named tropical storms (39‑73 mph winds), seven hurricanes (74 mph winds and above), and four major hurricanes (111 mph winds and above). The year will be remembered as the third-most active on record, as well as the third costliest, causing more than $80 billion in damage.

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Hurricane Ida

Scientists Sample Multiple Storms as Tropics Enter Peak for Hurricane Formation

Hurricane scientists at AOML sampled multiple storms this summer as the ­Atlantic entered its peak period for hurricane ­formation. From Elsa to Sam, the observations they gathered supported NOAA’s mission of preparing the public for severe weather by providing critical data for ­accurate, up-to-date forecasts.

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Habitat Altering Processes Are Uncovered for Reefs in the Eastern Pacific

Trying to predict how coral reefs will respond to warming oceans and a changing climate may be considered a daunting task for scientists. In the face of this challenge, scientists at AOML recently published a study that characterizes the organisms and processes that lead to coral reef accretion (build up) and bioerosion (break down) in the dynamic environments of the Gulf of Panama and Gulf of Chiriqui in the eastern Pacific.

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First page of 'Meridional overturning circulation and heat transport in the Atlantic Ocean' in State of Climate 2020.

Global Oceans: Meridional Overturning Circulation and Heat Transport in the Atlantic Ocean

VOLKOV, D.L., S. DONG, M. Lankhorst, M. KERSALÉ, A. Sanchez-Franks, C. SCHMID, J. Herrford, R.C. PEREZ, B.I. Moat, P. Brandt, C.S. MEINEN, M.O. BARINGER, E. Frajka-Williams, and D.A. Smeed.  Global oceans:  Meridional overturning circulation and heat transport in the Atlantic Ocean. In State of the Climate in 2020, J. Blunden, and T. Boyer (eds.). Bulletin of the American Meteorological Society, 102(8):S176-S179 (https://doi.org/10.1175/BAMS-D-21-0083.1) (2021).

The zonally integrated component of surface and deep currents, known as the meridional overturning circulation (MOC), plays an important role in Earth’s climate because it provides a mechanism for ocean meridional heat transport (MHT). The observing system for the Atlantic MOC/MHT consists of several basin-wide moored arrays as well as the combination of satellite altimetry and in situ (mainly Argo and eXpendable BathyThermograph [XBT]) measurements (Fig. 3.21a; e.g., Frajka-Williams et al. 2019)…

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A schematic of the major currents feeding the North Atlantic comprising the Northern limb of the AMOC.

Study Explores the Relationship of Anthropogenic Carbon and Ocean Circulation

In a recently published study in Nature Geoscience, scientists at AOML and international partners quantified the strength and variability of anthropogenic (man-made) carbon (Canth) transport in the North Atlantic Ocean. The study found that buildup of Canth in the North Atlantic is sensitive to the Atlantic Meridional Overturning Circulation (AMOC) strength and to Canth uptake at the ocean’s surface.

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GOMECC-4 Cruise Assesses Ocean Acidification Impacts in the Gulf of Mexico

AOML scientists and partners from an assortment of universities and Cooperative Institutes successfully completed the most comprehensive ocean acidification sampling of the Gulf of Mexico to date with the conclusion of the fourth Gulf of Mexico Ecosystems and Carbon Cruise, also known as the GOMECC-4 cruise. The research effort aboard the NOAA Ship Ronald H. Brown began out of Key West, Florida on September 13, 2021 with 25 scientists and graduate students aboard. It ended 39 days later on October 21 with a port stop in St. Petersburg, Florida.

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The view of a sunset from the deck of the 2021 PIRATA cruise.

Deep Ocean Warming Continues into the Vema Channel

In a recent study published in American Geophysical Union (AGU), scientists at NOAA’s Atlantic Oceanographic and Meteorological Laboratory (AOML) contributed to an international study that confirmed warming trends and the possibility of increased rates of warming in one of the deepest channels of the Southwest Atlantic ocean, the Vema Channel.

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