Tag: Sang-Ki Lee

Connection between Madden-Julian Oscillation and U.S Tornadoes may Provide Earlier Warning for Storms

Recently, scientists at NOAA’s Atlantic Oceanographic and Meteorological Laboratory (AOML) and the Cooperative Institute for Marine and Atmospheric Studies (CIMAS) explored the physical causes between U.S. tornado activity and the Madden-Julian Oscillation. In a study recently published in the Journal of Climate (Kim et al., 2020), they showed that a series of key atmosphere-ocean processes are involved in the remote impact of Madden-Julian Oscillation on U.S. tornado activity.

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Climate change may fuel more heat waves in the western U.S. and Great Lakes

AOML scientists, Hosmay Lopez and his colleagues used observations as well as model simulations of 20th Century climate and 21st Century projections to show that the occurrence of heat waves in the U.S. are on the rise and will continue to do so in the coming decades. This research was recently published in Nature Climate Change.

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Journal of Geophysical Research (JGR) Editors' Highlight

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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Proposed locations for the western and eastern PIES deployments in the subtropical South Pacific (stars). The magenta line shows the P06 cruise track along 32.5°S. Photo Credit: NOAA.

Project Explores Deep Ocean Heat Accumulation in the South Pacific

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. 

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Ocean Temperatures May Hold Key to Predicting Tornado Outbreaks

Tornadoes are one of nature’s most destructive forces. Recent violent and widespread tornado outbreaks in the United States, such as occurred in the spring of 2011, have caused significant loss of life and property. Currently, our capacity to predict tornadoes and other severe weather risks does not extend beyond seven days. Extending severe weather outlooks beyond seven days will assist emergency managers, businesses, and the public prepare the resources needed to prevent economic losses and protect communities. So how can scientists better predict when and where tornadoes are likely to strike, before the tornado season begins?

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(left column) Seasonality of precipitation and 850mb winds for the monsoon regions as measured by the difference between June-July-August-September (JJAS) minus annual mean precipitation and winds. (middle-column) shows the composite difference of JJAS precipitation (shaded) and 850mb wind for each monsoon region with respect to weak minus strong SAMHT at lead-time 20 years after the anomalous SAMHT. Blue stipples indicates regions where precipitation differences are significant at 95% confidence level based on a non-parametric Kolmogorov-Smirnov test. (right-column) Lag-lead Spearman ranked correlation between SAMHT and NH monsoon index. The blue dashed lines depict the 95% significance level based on a non-parametric Kendall-t test. Negative lag indicates periods when SAMHT leads the NH monsoon index. Periods with significant correlation between the SAMHT and monsoon are shaded blue. Image Credit: NOAA AOML.

Meridional heat transport in the South Atlantic reveals links with global monsoons

A recent paper published in the Journal of Climate led by PHOD researchers Hosmay Lopez, Shenfu Dong, Sang-Ki Lee, and Gustavo Goni provides a physical mechanism on how low frequency variability of the South Atlantic Meridional Heat Transport (SAMHT) associated with the Atlantic Meridional Overturning Circulation ( AMOC) may influence decadal variability of atmospheric circulation and monsoons. This is the first attempt to link the South Atlantic Overturning Circulation variability to weather and climate.

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