BATAL: The Balloon Measurement Campaigns of the Asian Tropopause Aerosol Layer
Fairlie, T. D.
Venkat Ratnam, M.
Kumar, B. S.
Pandit, A. K.
Akhil Raj, S. T.
Hemanth Kumar, A.
Singh, A. K.
Sinha, P. R.
Stenchikov, Georgiy L.
Durga Rao, M.
Wienhold, F. G.
Knepp, T. N.
KAUST DepartmentEarth Science and Engineering Program
Physical Sciences and Engineering (PSE) Division
Permanent link to this recordhttp://hdl.handle.net/10754/628450
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AbstractWe describe and show results from a series of field campaigns that used balloonborne instruments launched from India and Saudi Arabia during the summers 2014–17 to study the nature, formation, and impacts of the Asian Tropopause Aerosol Layer (ATAL). The campaign goals were to i) characterize the optical, physical, and chemical properties of the ATAL; ii) assess its impacts on water vapor and ozone; and iii) understand the role of convection in its formation. To address these objectives, we launched 68 balloons from four locations, one in Saudi Arabia and three in India, with payload weights ranging from 1.5 to 50 kg. We measured meteorological parameters; ozone; water vapor; and aerosol backscatter, concentration, volatility, and composition in the upper troposphere and lower stratosphere (UTLS) region. We found peaks in aerosol concentrations of up to 25 cm–3 for radii > 94 nm, associated with a scattering ratio at 940 nm of ∼1.9 near the cold-point tropopause. During medium-duration balloon flights near the tropopause, we collected aerosols and found, after offline ion chromatography analysis, the dominant presence of nitrate ions with a concentration of about 100 ng m–3. Deep convection was found to influence aerosol loadings 1 km above the cold-point tropopause. The Balloon Measurements of the Asian Tropopause Aerosol Layer (BATAL) project will continue for the next 3–4 years, and the results gathered will be used to formulate a future National Aeronautics and Space Administration–Indian Space Research Organisation (NASA–ISRO) airborne campaign with NASA high-altitude aircraft.
CitationVernier J-P, Fairlie TD, Deshler T, Venkat Ratnam M, Gadhavi H, et al. (2018) BATAL: The Balloon Measurement Campaigns of the Asian Tropopause Aerosol Layer. Bulletin of the American Meteorological Society 99: 955–973. Available: http://dx.doi.org/10.1175/BAMS-D-17-0014.1.
SponsorsS. Kumar is thankful to SERB, New Delhi, for providing him with a National Post Doctoral Fellowship (File No: PDF/2015/000691). We thank Drs. J. Kaye, K. Jucks, and R. Eckman at NASA HQ for supporting the BATAL campaigns since 2014 through the UARP and ACMAP programs. We acknowledge technicians and engineers from NARL, TIFR, BHU, and KAUST for their help during BATAL. We also thank the Indian Meteorological Department for providing Doppler weather radar images and MOSDAC for providing INSAT 3D images. We acknowledge Timothy Marvel for his help with making Fig. 1. We also thank Jacquelyn Charity-Hodnett, Syed Mustafa, and Kishore Kumar for their logistical supports. LABEX VOLTAIRE “Étude des géofluides et des Volatils-Terre, Atmosphère et Interfaces-Ressources et Environnement” (VOLTAIRE; ANR-10-LABX-100-01) is managed by the University of Orléans. The GEOS-5 data used in this study have been provided by the Global Modeling and Assimilation Office (GMAO) at NASA Goddard Space Flight Center through the online data portal in the NASA Center for Climate Simulation. We would like to note that Political borders are shown for cursory region identification and may not be accurate.
PublisherAmerican Meteorological Society