کد مقاله کد نشریه سال انتشار مقاله انگلیسی ترجمه فارسی نسخه تمام متن
5753882 1620709 2017 7 صفحه PDF سفارش دهید دانلود کنید
عنوان انگلیسی مقاله ISI
Cloud Condensation Nuclei activity in the tropical marine regions during Indian southwest monsoon
ترجمه فارسی عنوان
فعال شدن هسته های خلط آلود در مناطق دریایی گرمسیری در طول شهادت در غرب غربی هند
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علم هواشناسی
چکیده انگلیسی


- CCN distributions are presented for a wide range of supersaturations in the marine environment of Bay of Bengal.
- CCN concentration increases with prevailing winds.
- The results are relevant to the cloud microphysics and climate change impacts.

This paper presents the first onboard measurements of cloud condensation nuclei (CCN) distributions at super-saturations (ss) less than 0.5% (0.2% and 0.4%) and more than 0.5% (0.6% and 0.8%) as a function of prevailing winds during July and August over south to southeastern head-Bay region of Bay of Bengal (BoB). During monsoon season of 2012, the cross equatorial flow (CEF) along the belt 50°N-50°S was towards north and prevailing winds were stronger than normal by 2.6 ms−1 and 5.14 ms−1 respectively. Also, 2 and 5 low-pressure systems were formed during July and August 2012 respectively. Due to the strength of CEF, winds and low-pressure systems, mean value of wind speeds (U) observed onboard the ship during August was found to be stronger than that for July by 28%. As a result, mean values of CCN concentrations in August when winds were above 10 ms−1 were higher in magnitude by 9.5%, 15.6%, 13.4%, 12.13% and 11.9% for supersaturations of 0.2%, 0.4%, 0.6%, 0.8% and 1.0% respectively compared to corresponding means of CCN concentration during July when winds were below 10 ms−1. Wind-driven (U above 10 ms−1) CCN activity is found to be of high CCN concentrations at ss more than 0.5% despite active monsoonal cloud-aerosol interaction in the tropical marine environment. Relationships between CCN concentration and U when winds were above 10 ms−1 are found to be log10CCN = 0.057U + 2.4 and log10CCN = 0.047U + 2.6 at ss of 0.6% (R = 0.43) and 0.8% (R = 0.4) respectively, slopes of which appear to be reasonable climatic regulators for wind-induced CCN activity over south to southeastern head-Bay region of BoB.

It is worth to note that during its return journey towards south at Chennai port, SK-296 cruise sailed relatively away from the southeast coastline, where prevailing air mass were with U>10 ms−1 (August 2012). For August, relationships between CCN concentrations and wind speed (U > 10 ms−1) are log10CCN = 0.057U + 2.4 with the slope m (CCN to wind speed) of 0.057 for CCN concentrations activated at ss of 0.6%. For U > 10 ms−1 in the central Indian Ocean, shipboard measurements of Bigg, et al., (1995) suggested a relationship as log10CCN=0.04U+0.94 for CCN concentrations activated at ss of 0.6%.106

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Aerosol Science - Volume 114, December 2017, Pages 276-282
نویسندگان
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