Category: Physical Oceanography

Tracking Marine Debris

Researchers at AOML, NESDIS CoastWatch, and the University of Miami are currently exploring how the distribution of marine debris is affected by both ocean currents and wind. During a recent experiment, scientists deployed several prototype drifters in the Florida Current off the coast of Miami to simulate commonly found debris of varying weights and shapes. These drifters carry GPS transmitters that provide their location four times per day. 

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New Data Set to Improve Tropical Atlantic Ocean and Atmospheric Research

Researchers at NOAA AOML have released a new tropical Atlantic data set that includes several enhancements to improve data accuracy and data collection in the tropical Atlantic. The new data set is called enhanced PIRATA, or ePIRATA, and provides continuous records of upper-ocean temperature, salinity, and currents, together with meteorological data such as winds, humidity, and solar radiation. ePIRATA should prove valuable in better analyzing ocean and atmospheric processes in the tropical Atlantic.

PIRATA, the Prediction and Research Moored Array in the Tropical Atlantic, is a multinational observation network, established to improve knowledge and understanding of ocean-atmosphere variability in the tropical Atlantic. It is a joint project of Brazil, France and the United States of America, motivated by fundamental scientific issues and by societal needs for improved prediction of climate variability and its impact on the countries surrounding the tropical Atlantic basin. PIRATA provides measurements at 18 locations throughout the tropical Atlantic

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Decadal Modulations of Global Monsoons and Extreme Weather Events by SAMOC

There have been many efforts to understand the role of the Atlantic Meridional Overturning Circulation (AMOC) as a potential predictor of decadal climate variability, motivated partly by its inherent relationship with North Atlantic sea surface temperature. In contrast, there is currently limited knowledge about the underlying mechanisms that govern the South Atlantic Meridional Overturning Circulation (SAMOC) variability and how it might feedback into climate, partly due to the small number of direct observations in this ocean basin.

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Interannual-to-Decadal Variability of the SAMOC

Recent studies have suggested the possibility of the southern origin of the Atlantic MHT anomalies. These studies have used General Circulation Models (GCMs) to demonstrate covariability between the South Atlantic MOC (SAMOC) and the Southern Hemisphere westerlies at interannual to longer time scales. However, it has been pointed out that the sensitivity of the SAMOC to the changes in the Southern Hemisphere westerlies depends critically on the representation of mesoscale eddies in those models.

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Ocean dynamics played key role in Antarctic sea ice changes during past decades

“Much of the work on the cause of Antarctic sea ice over recent decades has focused on atmospheric drivers but this paper focuses on the ocean’s role. The authors analyse the trend of Antarctic sea ice over the past 35 years on the basis of satellite data and model simulations forced with atmospheric reanalysis products. Their findings suggest that ocean processes play a crucial role in determining the seasonality of sea ice trends. They also reveal that the sea-ice response is regional.”

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Underwater Glider Data Improved Intensity Forecasts of Hurricane Gonzalo

In a recent study published in Weather and Forecasting,* AOML researchers and their colleagues used NOAA’s HWRFHYCOM operational hurricane forecast model to quantify the impact of assimilating underwater glider data and other ocean observations into the intensity forecasts of Hurricane Gonzalo (2014). Gonzalo formed in the tropical North Atlantic east of the Lesser Antilles on October […]

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Southward Pathways of the Upper and Lower North Atlantic Deep Water

The Atlantic Meridional Overturning Circulation (AMOC) transports the upper warm water northward and the deep cold water southward in the Atlantic, and is a key component of the global energy balance. In many of the climate models that participate the Coupled Model Inter-comparison Project Phase 5 (CMIP5), the amplitudes of the AMOC agree very well with or are even larger than the observed value of about 18 Sv at 26.5N; but they still show cold upper ocean temperature biases in the North Atlantic.

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