Recent intensification of Amazonian flooding extremes is linked to the tropical Atlantic warming and tropical Pacific cooling

The Amazonian River basin hosts the one of the major global deep tropical convective systems, and thus drives the global Hadley and Walker circulations and the global hydrological cycle. Changes in the water cycle and deep convection activity in this region are, however, largely affected by remote oceans, especially the tropical Pacific, via the Walker circulation.... Continue Reading →

El Nino-induced suppression of Atlantic ITCZ contributes to the spring warming of the tropical North Atlantic

It is a well-known phenomenon that the Tropical North Atlantic (TNA) warms in boreal spring and early summer (April – June) following El Nino peaks in boreal winter (Enfield and Mayer, 1997). This involves formation of the so-called extratropical atmospheric stationary Rossby wave trains from the tropical Pacific (e.g., Lee et al., 2008). A new paper published... Continue Reading →

Increasing frequency of North American winter extremes caused by the eastward shift of the North Pacific Oscillation

The North Pacific Oscillation (NPO) is a dipole oscillation of the sea level pressure (or the atmospheric mass) between the subpolar low and subtropical high over the North Pacific Ocean. A study published in Nature Climate Change showed that the center of the NPO shifted eastward during the recent decades (1995-2014), and thus increased the frequency of... Continue Reading →

2019 US severe weather season kicked off with deadly tornado outbreak in Alabama and Georgia

2019 US severe weather season started with 39 reported tornadoes throughout southeastern Alabama, Georgia, Florida Panhandle and South Carolina in March 3. At least 20 people have been confirmed dead in Lee County, Alabama alone. On March 2 at 10:51am, NOAA/SPC forecasted an enhanced risk of severe thunderstorms for Sunday, March 3, from southern Alabama... Continue Reading →

Pantropical inter-ocean interactions & the rising influence of tropical Atlantic Ocean

Conventional view so far has been that El Nino - Southern Oscillation (ENSO) is largely responsible for energizing the dominant modes of SST variability  in the tropical Atlantic and Indian Oceans through changes in the Walker circulation and extratropical atmospheric waves. However, recent studies have shown that SST variability in the tropical Atlantic and Indian... Continue Reading →

Ocean precursors to the extreme Atlantic 2017 hurricane season

A recent study published in nature communications investigated three ocean precursors, namely surface latent heat flux and wind stress curl over the main development region (MDR, 10–20°N, 20–80°W) and the Atlantic Meridional Overturning Circulation (AMOC) at 26.5°N, to the active hurricane seasons in 2005, 2010 and 2017. The study showed that in 2005 and 2010, a weakened... Continue Reading →

Recent warming of the Indian Ocean suppresses the Indian summer monsoon circulation

A recent article published in Science Advances analyzed an atmospheric reanalysis dataset (MERRA2) covering the 1980–2016 period to show that a significant warming occurred in the Indian Ocean over the study period, and thus reduced the temperature difference between the Indian subcontinent and Indian Ocean in boreal summer. The reduced land-ocean temperature difference in turn produced anomalous... Continue Reading →

Arctic sea-ice decrease may suppress U.S. tornado activity in summer

The observed losses in  Arctic sea ice during the past decades have been linked to the relaxation of poleward thickness gradients (thus weakened zonal winds) and a slower eastward progression of Rossby waves in the upper-level, which help promote prolonged extreme weather conditions, such as heat waves, within the mid-latitudes (e.g., Francis & Vavrus, 2012). However, the background... Continue Reading →

June 14, 2018 – ENSO Update: El Niño Watch

NOAA CPC's current ENSO alert system status is El Nino Watch: ENSO-neutral is favored through Northern Hemisphere summer 2018, with the chance for El Niño increasing to 50% during fall, and ~65% during winter 2018-19. http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml https://www.climate.gov/news-features/blogs/enso/june-2018-enso-update-el-ni%C3%B1o-watch  

Powered by WordPress.com.

Up ↑