John C . H . Chiang

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We investigate the causes for a strong high latitude imposed ice (land or sea) influence on the marine Intertropical Convergence Zone (ITCZ) in the Community Climate Model version 3 coupled to a 50-m slab ocean. The marine ITCZ in all the ocean basins shift meridionally away from the hemisphere with an imposed added ice cover, altering the global Hadley(More)
The warming of the entire tropical free troposphere in response to El Niño is well established, and suggests a tropical mechanism for the El Niño–Southern Oscillation (ENSO) teleconnection. The potential impact of this warming on remote tropical climates is examined through investigating the adjustment of a single-column model to imposed tropospheric(More)
Elevated heating by cumulus convection and sea surface temperature gradients are both thought to contribute to surface winds over tropical oceans. The relative strength and role of each mechanism is examined by imposing forcing derived from data on a linear primitive equation model with idealized parameterizations for the two forcings, and comparing the(More)
[1] Recent paleoproxy records suggest that the mean latitude of the Atlantic Intertropical Convergence Zone (ITCZ) varied synchronously with North Atlantic climate over a range of timescales throughout the Holocene and Last Glacial Maximum. We show that the present-day ‘‘meridional mode’’ of atmosphere-ocean variability in the tropical Atlantic is a(More)
Recent developments in Tropical Atlantic Variability (TAV) identify the El Niño–Southern Oscillation (ENSO) as one of the leading factors in the interannual climate variability of the basin. An ENSO event results in Tropicwide anomalies in the atmospheric circulation that have a direct effect on precipitation variability, as well as an indirect effect, that(More)
[1] We examine the first decade of adjustment of the North Atlantic climate following an abrupt freshening of the high North Atlantic and resulting slowdown of the Atlantic meridional overturning circulation (AMOC) in a coupled model, with reference to previously proposed teleconnection mechanisms. After an initial ocean-driven cooling at the(More)
We show in climate model experiments that large-scale afforestation in northern mid-latitudes warms the Northern Hemisphere and alters global circulation patterns. An expansion of dark forests increases the absorption of solar energy and increases surface temperature, particularly in regions where the land surface is unable to compensate with latent heat(More)
[1] Two remote sensing data sets, the Tropical Rainfall Measurement Mission Sea Surface Temperature (SST) and the NASA QuikSCAT ocean surface wind vectors, are analysed to study ocean-atmosphere interactions in cold SST regions formed in the trail of two typhoon events. Anomalously cold SST patches up to 6 C below the surrounding warm tropical ocean SST are(More)
The adjustment of the tropical climate outside the Pacific (the “remote Tropics”) to the abrupt onset of El Niño conditions is examined in a tropical atmosphere model that assumes simplified vertical structure and quasi-equilibrium (QE) convective closure. The El Niño signal is rapidly ( 1 week) communicated to the remote Tropics via an eastward-propagating(More)
The temperature contrast between the Northern and Southern Hemispheres—the interhemispheric temperature asymmetry (ITA)—is an emerging indicator of global climate change, potentially relevant to the Hadley circulation and tropical rainfall. The authors examine the ITA in historical observations and in phases 3 and 5 of the CoupledModel Intercomparison(More)