Author/Authors :
Jenkins، نويسنده , , Gregory S. and Robjhon، نويسنده , , Miliaritiana L. and Demoz، نويسنده , , Belay and Stockwell، نويسنده , , William R. and Ndiaye، نويسنده , , Seydi A. and Drame، نويسنده , , Mamadou S. and Gueye، نويسنده , , Moussa and Smith، نويسنده , , Jonathan W. and Luna-Cruz، نويسنده , , Yaitza and Clark، نويسنده , , Johnathan and Holt، نويسنده , , Jalisa and Paulin، نويسنده , , Casey and Brickhouse، نويسنده , , Ashley M. Williams، نويسنده , , Aneese and Abdullah، نويسنده , , Ajamu and Reyes، نويسنده , , Ashford and Mendes، نويسنده , , Luis and Valentine، نويسنده , , Adriel and Camara، نويسنده , , Moctar، نويسنده ,
Abstract :
Ozone soundings are launched during two Intensive Observing Periods (IOPs) from Dakar, Senegal; Sao Vicente, Cape Verde; and St James, Barbados to investigate ozone variability across the North Tropical Atlantic during June/July and August/September 2010. Two objectives of the campaign are to compare background tropospheric ozone mixing ratios and its variability associated with the Saharan Air Layer (SAL) and African Easterly Waves (AEWs) at sites located in the Eastern and Western Tropical Atlantic Ocean. During IOP1 (June–July), reduced ozone mixing ratios are found in the SAL with elevated ozone levels at the SALʹs base and above it. During IOP I, the tropospheric column ozone (TCO) is higher at Cape Verde (27.5 DU) when compared to Barbados (19.8 DU). During IOP II (August–September) ozone-rich air is found above 500 hPa prior to the passage of AEW or developing tropical cyclones. The observed larger mixing ratios of middle/upper tropospheric ozone are most prominent at Dakar prior to the passage of an AEW, which we attribute to lightning NOx. During IOP II the tropospheric column ozone is highest at Dakar (30.5 DU) when compared to Cape Verde (20.2 DU) and Barbados (17.2 DU).
Keywords :
Tropics , African Easterly Waves , lightning , dust , Saharan air layer
