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 →
Net retreat of Antarctic glacier grounding lines
Grounding lines are a key indicator of ice-sheet instability, because changes in their position reflect imbalance with the surrounding ocean and affect the flow of inland ice. Although the grounding lines of several Antarctic glaciers have retreated rapidly due to ocean-driven melting, records are too scarce to assess the scale of the imbalance. Here, we... 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 →
Ocean acidification affects coral growth by reducing skeletal density
Ocean acidification (OA) threatens coral reef futures by reducing the concentration of carbonate ions that corals need to construct their skeletons. However, quantitative predictions of reef futures under OA are confounded by mixed responses of corals to OA in experiments and field observations. We modeled the skeletal growth of a dominant reef-building coral, Porites, as a... Continue Reading →
Significant changes in the nutrient, carbon, and trace metal balances of the Arctic Ocean are underway
Rising temperatures in the Arctic Ocean region are responsible for changes such as reduced ice cover, permafrost thawing, and increased river discharge, which, together, alter nutrient and carbon cycles over the vast Arctic continental shelf. We show that the concentration of radium-228, sourced to seawater through sediment-water exchange processes, has increased substantially in surface waters... Continue Reading →
On the fragile relationship between El Niño and California rainfall
This study newly accepted in Geophysical Research Letters examined why California experienced extremely wet winter and spring conditions during the 1997-98 and 1982-83 El Niños, but near normal rainfall during the extremely strong 2015-16 El Niño. Statistical data analyses and simple model experiments were used to show that sufficiently warm and persistent sea surface temperature anomalies... Continue Reading →
Ocean to Climate 