Vertical and latitudinal variation of the intertropical convergence zone derived using GPS radio occultation measurements

Abstract

Using GPS radio occultation refractivity data collected over the period of 2002-2013, we present a new method for identification of the intertropical convergence zone (ITCZ). The ITCZ is identified by estimating the maximum in the monthly meridional refractivity and specific humidity field by applying a Gaussian fit at each longitude. The interannual variability and climatology of the ITCZ is presented from 12 years of refractivity data. This new method captures all the general features of ITCZ extent and its variability. We also examine the effects of the ITCZ vertically during different seasons. The ITCZ is observed mostly at eastern Pacific in May month, and it is zonally distributed in the September and October months of each year. The zonal variability is large between lower and higher levels, particularly over the Indian monsoon and western Pacific. The latitudinal difference in the vertical extent between 850 hPa and higher levels is larger during the northern hemisphere (NH) summer than NH winter.

Multiple drivers of production and particle export in the western tropical North Atlantic

“…Large amounts of dust particles emitted from the Sahara desert (Yu et al 2015a) are blown across the Atlantic Ocean, reaching the Americas and the Caribbean (e.g., Prospero et al 1970;Prospero 1999;Prospero et al 2014). Along with the seasonal movement of the Intertropical Convergence Zone (Adams et al 2012;Basha et al 2015), the dust is transported by the easterly trade winds towards North America and the Caribbean Sea during summer and fall, and by the northeasterly trade winds towards the Amazon River basin during winter and spring (Prospero et al 2014). Recent satellite observations point to ca.…”

A 550,000-year record of East Asian monsoon rainfall from 10 Be in loess

“…During boreal summer, the ITCZ migrates into the Northern Hemisphere (figs. S2 and S3) in response to warmer northern and cooler Southern Hemisphere tropics and subtropics (22). Over Asia, this migration is accompanied by northward migration of the upper-tropospheric subtropical zonal westerly jet (23,24), which moves north of the TP during mid-summer.…”

Coccolithophore fluxes in the open tropical North Atlantic: influence of thermocline depth, Amazon water, and Saharan dust

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