Abstract
The first measurements of cloud condensation nuclei (CCN) at five supersaturations were carried out onboard the research vessel “Sagar Kanya” (cruise SK-296) from the south to the head-bay of the Bay of Bengal as part of the Continental Tropical Convergence Zone (CTCZ) Project during the Indian summer monsoon of 2012. In this paper, we assess the diurnal variation in CCN distributions at supersaturations from 0.2% to 1% (in steps of 0.2%) and the power-law fit at supersaturation of 1%. The diurnal pattern shows peaks in CCN concentration (NCCN) at supersaturations from 0.2% to 1% between 0600 and 0700 LST (local standard time, UTC+0530), with relatively low concentrations between 1200 and 1400 LST, followed by a peak at around 1800 LST. The power-law fit for the CCN distribution at different supersaturation levels relates the empirical exponent (k) of supersaturation (%) and the NCCN at a supersaturation of 1%. The NCCN at a supersaturation of 0.4% is observed to vary from 702 cm−3 to 1289 cm−3, with a mean of 961±161 cm−3 (95% confidence interval), representing the CCN activity of marine air masses. Whereas, the mean NCCN of 1628±193 cm−3 at a supersaturation of 1% is higher than anticipated for the marine background. When the number of CCN spectra is 1293, the value of k is 0.57±0.03 (99% confidence interval) and its probability distribution shows cumulative counts significant at k ≈ 0.55±0.25. The results are found to be better at representing the features of the marine environment (103 cm−3 and k ≈ 0.5) and useful for validating CCN closure studies for Indian sea regions.
摘 要
作为大陆热带辐合带 (CTCZ) 计划的组成部分, 利用“萨加尔坎亚”科考船(编号SK-296)船载仪器对 2012 年印度夏季风期间孟加拉湾南部到前端地区五种过饱和度下的云凝结核 (CCN) 进行了首次观测. 本文分析了过饱和度从 0.2%到 1%(间隔为 0.2%) 下的 CCN 日变化特征和在 1%过饱和度下使用幂函数拟合的 CCN 谱分布. 日变化特征显示过饱和度从 0.2%到 1%时 CCN数浓度(NCCN) 在 0600 到 0700 LST(当地时间, 协调世界时 +0530)出现峰值, 接着在 1200 到 1400 LST 出现相对低值, 然后在 1800 LST 左右又出现峰值. 不同过饱和度下幂函数拟合的 CCN 谱分布依赖于和过饱和(%)相关的经验参数 k 以及 1%过饱和度下的 CCN 数浓度. 过饱和度为 0.4%时 CCN 数浓度的变化范围为 702 cm−3 到 1289 cm−3, 平均值为 961 ± 161 cm−3(95%置信区间), 代表了海洋性 CCN 特征. 然而当过饱和度为 1%时, 1628 ± 193 cm−3 的平均 NCCN 高于预期的海洋背景 CCN 数浓度. 当 CCN 谱的参数 C 值是 1293 时, 参数 k 值为 0.57 ± 0.03(99%置信区间)并且其概率分布的累计频数显著出现在 k ≈ 0.55 ± 0.25. 上述结果能够更好的代表海洋性 CCN 特征(C=103 cm−3 和 k ≈ 0.5)并且有助于验证印度洋地区的 CCN 闭合结果.
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References
Andreae, M. O., and D. Rosenfeld, 2008: Aerosol-cloudprecipitation interactions. Part 1. The nature and sources of cloud-active aerosols. Earth-Science Reviews, 89, 13–41, doi: 10.1016/j.earscirev.2008.03.001.
Andreae, M. O., 2009: Correlation between cloud condensation nuclei concentration and aerosol optical thickness in remote and polluted regions. Atmos. Chem. Phys. 9, 543–556, doi: 10.5194/acp-9-543-2009.
Asmi, E., E. Freney, M. Hervo, D. Picard, C. Rose, A. Colomb, and K. Sellegri, 2012: Aerosol cloud activation in summer and winter at puy-de-Dôme high aLSTitude site in France. Atmos. Chem. Phys., 12, 11 589–11 607, doi: 10.5194/acp-12115892012.
Bougiatioti, A., A. Nenes, C. Fountoukis, N. Kalivitis, S. N. Pandis, and N. Mihalopoulos, 2011: Size-resolved CCN distributions and activation kinetics of aged continental and marine aerosol. Atmos. Chem. Phys, 11, 8791–8808, 10.5194/acp-11- 8791-2011.
CTCZ-Scientific Steering Committee, 2011: Proposal for Continental Tropical Convergence Zone (CTCZ) programme. CTCZ-Scientific Steering Committee, 66 pp.
Dinger, J. E., H. B. Howell, and T. A. Wojciechowski, 1970: On the source and composition of cloud nuclei in a subsident air mass over the North Atlantic. J. Atmos. Sci., 27, 791–797, doi: 10.1175/1520-0469(1970)027<0791:OTSACO>2.0.CO;2.
Ervens, B., and Coauthors, 2010: CCN predictions using simplified assumptions of organic aerosol composition and mixing state: A synthesis from six different locations. Atmos. Chem. Phys., 10, 4795–4807, doi: 10.5194/acp-1047952010.
Fitzgerald, J. W., 1973: Dependence of the supersaturation spectrum of CCN on aerosol size distribution and composition. J. Atmos. Sci., 30(4), 628–634, doi: 10.1175/1520-0469(1973)030<0628:DOTSSO>2.0.CO;2.
Fitzgerald, J. W., 1991: Marine aerosols: A review. Atmospheric Environment. Part A. General Topics, 25(3–4), 533–545, doi: 10.1016/0960-1686(91)90050-H.
Gras, J. L., 1990: Cloud condensation nuclei over the Southern Ocean. Geophys. Res. Lett., 17, 1565–1567, doi: 10.1029/GL017i010p01565.
Hegg, D. A., and P. V. Hobbs, 1992: Cloud condensation nuclei in the marine atmosphere: A Review, Proceedings of the Thirteenth International Conference on Nucleation and Atmospheric Aerosols, Hampton, VA, Deepak Publishing, 181–192.
Hegg, D. A., D. S. Covert, and H. H. Jonsson, 2008: Measurements of size-resolved hygroscopicity in the California coastal zone. Atmos. Chem. Phys., 8, 7193–7203, doi:10.5194/acp-8-7193-2008.
Hegg, D. A., D. S. Covert, D. S., H. H. Jonsson, H. H., and R. Woods, R., 2009: Differentiating natural and anthropogenic cloud condensation nuclei in the California coastal zone. Tellus, 61B, 669–676, http://dx.doi.org/10.1111/j.1600-0889.2009.00435.x.
Hegg, D. A., L. F. Radke, L. F., and P. V. Hobbs, 1991: Measurements of Aitken nuclei and cloud condensation nuclei in the marine atmosphere and their relation to the DMS-cloudclimate hypothesis. J. Geophys. Res., 96, 18 727–18 733, doi: 10.1029/91JD01870.
Hudson, J. G., 2007: Variability of the relationship between particle size and cloud-nucleating ability. Geophys. Res. Lett., 34, L08801, doi: 10.1029/2006GL028850.
Hudson, J. G., T. J. Garrett, P. V. Hobbs, S. R. Strader, Y. H. Xie, and S. S. Yum, 2000: Cloud condensation nuclei and ship tracks. J. Atmos. Sci., 57, 2696–2706, doi: 10.1175/1520-0469(2000)057<2696:CCNAST>2.0.CO;2.
Krüger, M. L., and Coauthors, 2014: Assessment of cloud supersaturation by size-resolved aerosol particle and cloud condensation nuclei (CCN) measurements. Atmospheric Measurement Techniques, 7, 2615–2629, doi: 10.5194/amt-7-2615-2014.
Leena, P. P., G. Pandithurai, V. Anilkumar, P. Murugavel, S. M. Sonbawne, and K. K. Dani, 2016: Seasonal variability in aerosol, CCN and their relationship observed at a high aLSTitude site in Western Ghats. Meteor. Atmos. Phys., 128, 143–153, doi: 10.1007/s00703-015-0406-0-.
McFiggans, G., and Coauthors, LST2006: The effect of physical and chemical aerosol properties on warm cloud droplet activation. Atmos. Chem. Phys., 6, 2593–2649, doi: 10.5194/acp-62593-2006.
Murugavel, P., and D. M. Chate, 2011: Volatile properties of atmospheric aerosols during nucleation events at Pune, India. Journal of Earth System Science, 120, 1–17, doi: 10.1007/s12040-011-0072-7.
Petters, M. D., and S. M. Kreidenweis, 2007: A single parameter representation of hygroscopic growth and cloud condensation nucleus activity. Atmos. Chem. Phys., 7, 1961–1971, doi: 10.5194/acp-7-1961-2007.
Pruppacher, H. R., and J. D. Klett, 2010: Microphysics of Clouds and Precipitation: Atmospheric and Oceanographic Sciences Library. Springer, 954 pp.
Ramana, M. V., and A. Devi, 2016: CCN concentrations and BC warming influenced by maritime ship emitted aerosol plumes over southern Bay of Bengal. Sci. Rep., 6, 30416, doi: 10.1038/srep30416.
Roberts, G. C., and A. Nenes, 2005: A continuous-flow streamwise thermal-gradient CCN chamber for atmospheric measurements. Aerosol Science and Technology, 39, 206–221, doi: 10.1080/027868290913988.
Rose, D., S. S. Gunthe, E. Mikhailov, G. P. Frank, U. Dusek, M. O. Andreae, and U. Pöschl, 2008: Calibration and measurement uncertainties of a continuous-flow cloud condensation nuclei counter (DMT-CCNC): CCN activation of ammonium sulfate and sodium chloride aerosol particles in theory and experiment. Atmos. Chem. Phys., 8, 1153–1179, doi: 10.5194/acp-8-1153-2008.
Su, H., and Coauthors, 2010: Hygroscopicity distribution concept for measurement data analysis and modeling of aerosol particle mixing state with regard to hygroscopic growth and CCN activation. Atmos. Chem. Phys., 10, 7489–7503, doi: 10.5194/acp-10-7489-2010.
Varghese, M., and Coauthors, 2015: Airborne and ground based CCN spectral characteristics: Inferences from CAIPEEX-2011. Atmos. Environ., 125, 324–336, doi: 10.1016/j.atmosenv.2015.06.041.
Acknowledgements
The Indian Institute of Tropical Meteorology (IITM), Pune, is supported by the Ministry of Earth Sciences, Government of India, New Delhi. The authors thank Prof. Ravi S. NANJUNDIAH, Director, IITM. Special thanks go to Prof. G. S. BHAT, a CTCZ science expert, for his guidance and encouragement as well as providing us the onboard SK-296 weather data. Also, the authors thank Dr. R. HATWAR and Dr. A. ALMEIDA for their support in conducting the SK-296 cruise campaign. The authors would like to acknowledge the crew members of “Sagar Kanya” (SK-296) for their cooperation and support during the field campaign. One of the authors (PCSD) would also like to thank the authorities at Amity University Gurgaon for their support.
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Chate, D.M., Waghmare, R.T., Jena, C.K. et al. Cloud condensation nuclei over the Bay of Bengal during the Indian summer monsoon. Adv. Atmos. Sci. 35, 218–223 (2018). https://doi.org/10.1007/s00376-017-6331-z
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DOI: https://doi.org/10.1007/s00376-017-6331-z