Climate projections for the twenty-first century suggest an increase in the occurrence of heat waves. However, the time at which externally forced signals of anthropogenic climate change (ACC) emerge against background natural variability (time of emergence (ToE)) has been challenging to quantify, which makes future heat-wave projections uncertain. In a new article published in Nature Climate Change (Lopez et al., 2018), Hosmay Lopez and his team combine observations and model simulations under present and future forcing to assess how internal variability and ACC modulate US heat waves.
AOML oceanographers Christopher Meinen and Molly Baringer participated in the development of a new thirteen-year-long record of the daily Atlantic ocean overturning that has recently been released. This project is a collaboration between a large team of researchers at NOAA, at the University of Miami ,and at the National Oceanography Centre in Southampton, United Kingdom.
The manuscript “An enhanced PIRATA data set for tropical Atlantic ocean-atmosphere research”, by Greg Foltz, Claudia Schmid, and Rick Lumpkin, was accepted for publication in Journal of Climate. It describes a new set of daily time series (ePIRATA) that is based on the measurements from 17 moored buoys of the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA).
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.
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.
“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.”
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 […]
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.
One of the most challenging questions in global climate change studies today is how quickly, or if, heat that accumulates within the Earth system penetrates into the deep ocean. Scientists with the University of Miami (UM), AOML, and NASA’s Jet Propulsion Laboratory (JPL) recently tackled this question by using a combination of present-day satellite and in situ observing systems to study the distribution of heat in the oceans.
Remote influence of Interdecadal Pacific Oscillation on the South Atlantic meridional overturning circulation variability
This study explores potential factors that may influence decadal variability of the South Atlantic meridional overturning circulation (SAMOC) by using observational data as well as surface-forced ocean model runs and a fully coupled climate model run.