Hurricane Harvey links to ocean heat content and climate change adaptation

While hurricanes occur naturally, human‐caused climate change is supercharging them and exacerbating the risk of major damage. Here, using ocean and atmosphere observations, we demonstrate links between increased upper ocean heat content due to global warming with the extreme rainfalls from recent hurricanes. Hurricane Harvey provides an excellent case study as it was isolated in... Continue Reading →

Ocean dynamics plays a key role in driving the Atlantic Multidecadal Oscillation (AMO)

The recently proposed atmosphere-forced thermodynamics mechanism of the AMO challenged the well-known ocean dynamics mechanism, and thus it is important to identify a key feature associated with the AMO that can be used to distinguish between the two mechanisms. In this study, the spatial structure of AMO is analyzed and compared between the observations and... Continue Reading →

Northward shift of the East Asian summer monsoon enhances US summer rainfall variability

The strength of the dominant variability of contiguous United States (CONUS) summer rainfall during 1960–2013 experiences an interdecadal change in the early 1990s. Before the early 1990s, the variation in CONUS summer rainfall is relatively small in amplitude (standard deviation: 0.64  mm per day), whereas after it amplifies remarkably, with its standard deviation (1.31  mm... Continue Reading →

The boundary that separates the humid East US from the semi-arid West is shifting eastward

The 100th meridian bisects the Great Plains of the United States and effectively divides the continent into more arid western and less arid eastern halves and is well expressed in terms of vegetation, land hydrology, crops, and the farm economy. Here, it is considered how this arid–humid divide will change in intensity and location during... Continue Reading →

Is AMOC slowing down?

A recent article appeared in Nature  suggested that the AMOC has been very weak during the past 150 years since the end of the Little Ice Age (LIA) , and that enhanced freshwater fluxes from the Arctic and Nordic seas towards the end of the LIA weakened Labrador Sea convection and thus the AMOC. They... Continue Reading →

Influence of global warming on U.S. heat waves may be felt first in the West and Great Lakes regions

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. Here we combine observations and model simulations... Continue Reading →

Evidence linking Arctic amplification to extreme weather in mid-latitudes

Arctic amplification (AA) – the observed enhanced warming in high northern latitudes relative to the northern hemisphere – is evident in lower-tropospheric temperatures and in 1000-to-500 hPa thicknesses. Daily fields of 500 hPa heights from the National Centers for Environmental Prediction Reanalysis are analyzed over N. America and the N. Atlantic to assess changes in north-south (Rossby)... Continue Reading →

Arctic report card: update for 2017

NOAA's Arctic program released Arctic Report Card Update for 2017. The report finds "Arctic shows no sign of returning to reliably frozen region of recent past decades", "The sea ice cover continues to be relatively young and thin with older, thicker ice comprising only 21% of the ice cover in 2017 compared to 45% in 1985.", and... Continue Reading →

Explaining extreme events from a climate perspective

This special report of the Bulletin of the American Meteorological Society (BAMS) presents some extreme events in 2016, such as the record global heat, the heat across Asia, the 2015-16 El Niño and a marine heat wave off the coast of Alaska, and discusses how human-caused climate change may have affected the strength and likelihood of these extreme events.... Continue Reading →

Powered by WordPress.com.

Up ↑