The tropical Pacific Ocean is a climatically important region, home to El Niño and the Southern Oscillation. The simulation of its climate remains a challenge for global coupled ocean–atmosphere models, which suffer large biases especially in reproducing the observed meridional asymmetry across the equator in sea surface temperature (SST) and rainfall. A basin ocean general circulation model is...

1. Tropical montane forests house unusual and diverse biota and are considered highly vulnerable to climate change, particularly near the trade wind inversion (TWI) – the upper end of the cloud belt that defines tropical montane cloud forest (TMCF). The upper cloud belt has two possible futures: one hypothesis postulates a ‘lifting cloud base’, raising both the upper and lower ends of the cloud...

[1] In late boreal spring, especially May, a strong relationship exists in observations among precipitation anomalies over equatorial South America and the Atlantic intertropical convergence zone (ITCZ), and eastern equatorial Pacific and central equatorial Atlantic sea surface temperature anomalies (SSTA). A chain of correlations of equatorial Pacific SSTA, western equatorial Atlantic wind str...

This paper examines the dynamics of large-scale overturning circulations in the tropical atmosphere using an idealized zonally symmetric model on the equatorial b-plane. Under certain simplifications of its coefficients, the elliptic partial differential equation for the transverse circulation can be solved by first performing a vertical transform to obtain a horizontal structure equation, and ...

[1] The stable carbon (dC) and oxygen (dO) isotopic compositions of four Holocene specimens of Montastraea sp. and Siderastrea sp. coral skeletons from the Dominican Republic were analyzed to examine decadal-scale fluctuations in regional precipitation. The specimens range in length from 47 to 197 years individually and range in age from 7.2 to 5.2 kyr. Oscillations in the dC and dO of coral sk...

precipitation changes in the region on orbital timescales. 22 The Nordeste, a semi-arid region in northeastern Brazil, 23 is known for its severe and recurrent droughts, which cause 24 socioeconomic problems for millions of people. Observational and 25 modelling studies have convincingly linked below-normal rainfall 26 in the Nordeste during the rainy season (February, March and 27 April) to pe...

This study uses a shallow-water, normal-mode spectral model to examine the non-linear potential vorticity (PV) dynamics of the break¬down of both infinite an finite-length initial vorticity strips, simulating the inter-tropical convergence zone (ITCZ) found near the tropical eastern Pacific region. Irregularities in convection and diabatic heating are simulated using uniformly and randomly spac...

A set of coupled ocean-atmosphere(-vegetation) simulations using state of the art climate models is now available for the Last Glacial Maximum (LGM) and the MidHolocene (MH) through the second phase of the Paleoclimate Modeling Intercomparison Project (PMIP2). Here we quantify the latitudinal shift of the location of the Intertropical Convergence Zone (ITCZ) in the tropical regions during borea...

Millennial-scale cooling events termed Heinrich Stadials punctuated Northern Hemisphere climate during the last glacial period. Latitudinal shifts of the intertropical convergence zone (ITCZ) are thought to have rapidly propagated these abrupt climatic signals southward, influencing the evolution of Southern Hemisphere climates and contributing to major reorganisation of the global oceanatmosph...

Precipitation and high-level cloud (HLC) areas in association with the large-scale circulation over the tropical Pacific are analyzed for simulations of nineteen Coupled Model Intercomparison Project Phase 3 (CMIP3) models with observations for 16 years of 1984–1999. The distribution of rainfall and HLC areas are composited around the geographical center of tropospheric upper-level (200 hPa) di...