The current state-of-the-art climate models suggest that the human-induced weakening of the Atlantic Meridional Overturning Circulation (AMOC) has already begun since the mid-1980s. However, continuous direct observational records during the past two decades have shown no clear sign of a slowing down of the AMOC. To shed light on this apparent contradiction, a new study... Continue Reading →
Tropical cyclone (TC) activity results in substantial loss of life and property damage. While the Atlantic basin has experienced a pronounced increase in accumulated cyclone energy (ACE) and the number of TCs over the past 50 years, TC-resolving climate models project a slight decrease in TC frequency throughout the 21st century (e.g., Roberts et al.,... Continue Reading →
Scientists have been monitoring the Atlantic Meridional Overturning Circulation (AMOC) at around 26.5°N since April 2004 through the RAPID/Meridional Overturning Circulation and Heatflux Array/Western Boundary Time Series moored array (RAPID). The newly released RAPID dataset fully incorporated a recent geomagnetic correction of the submarine cable measurement of the Florida Current transport, a critical component of... Continue Reading →
Heatwaves usually come with dry conditions because the regions under the so-called heat dome, which is typically responsible for severe heatwave events, are deprived of moisture and rainfall. However, in the southern US states under semi-tropical environments, "moist" heatwave events may occur, causing both the temperature and humidity stresses on human physiology. But, you may... Continue Reading →
During the satellite era (1979-present), the tropical Pacific Ocean has warmed significantly less than the other tropical oceans in response to increasing greenhouse gases (GHGs). This La Niña-like warming trend in observations is in disagreement with the El Niño-like warming trend projected by the Coupled Model Intercomparison Project (CMIP) models for both the 20th and... Continue Reading →
According to the recharge-discharge oscillator theory (Jin, 1997), the leading mode of tropical Pacific upper ocean heat content anomalies is a predictor (or a precursor) for the onset of El Niño - Southern Oscillation (ENSO) at the interannual time scale. A new study published in Nature (Zhao et al., 2024) utilized multiple global sea surface... Continue Reading →
A new study published in Science (Zhou and McManus, 2024) reconstructed the land ice melting (or discharge) rate during the intermittent events of ice melting in the last glacial period (i.e., Heinrich events). The study showed that the present-day Greenland Ice Sheet melting rate (since the 1980s) is comparable to that during weak-to-moderate strength Heinrich events. This... Continue Reading →
The Atlantic Meridional Overturning Circulation (AMOC) transports warm and salty upper ocean water to the subpolar North Atlantic where the upper ocean releases some heat to the atmosphere. Due to the surface cooling and the high salinity (i.e., salty), the upper ocean water becomes heavier and thus sinks down to the deep ocean and then... Continue Reading →
As a climate scientist, I have worked and interacted with many weather scientists in the past 20 years or so. I am also currently in a task force team to advance subseasonal (2~4 weeks) forecasts of severe weather activity in the U.S. I have learned so much from weather scientists about how longer-term climate processes... Continue Reading →
Two important atmospheric jet streams that shape the extratropical zonal wind field in both hemispheres are the subtropical jet and the subpolar jet. The subtropical jet is located around 30° latitude line at the boundary between the Hadley cell and the Ferrel cell, and is predominantly a high-altitude feature. Since it is largely in thermal-wind... Continue Reading →
