Knowledge of relations among ocean biogeochemical and cloud properties will help to plan experiments necessary to understand the mechanisms and processes underlying the links between ocean and atmosphere interactions. Here, we explored the associations between ocean biogeochemical and cloud properties in a region that seasonally experiences polluted and pristine atmospheric conditions in winter and summer, respectively. The implications of ocean surface chlorophyll-a and biogeochemical fluxes (sea salt, dimethyl sulphide and organic fraction in sea spray) to cloud properties (cloud effective radii (R_e), cloud optical thickness, and cloud droplet number concentration (CDNC)) were studied using MODIS (Terra, Collection 6, L3) monthly data from 2001 to 2015 along with reanalysis information. We have adopted a climatological averaging approach in time (monthly, seasonal and annual) and space (coastal, open and total (basin) Arabian Sea). This approach was used to minimize incompatibility, if any, between ocean and cloud properties arising from spatio-temporal lags due to different dynamics in the respective boundary layers. The trends in monthly means suggest decreases in chlorophyll-a and CDNC, while R_e increased over the Arabian Sea basin during 2001–2015. Variability at the basin scale (expressed as standard deviation in each month, SD) exceeded mean values of respective months for chlorophyll-a, whereas it was nearly half of the mean values for CDNC. An increase in R_e seems facilitated more during warmer 2011–2015 than in the 2001–2010 period, which coincided with the decrease in CDNC. Fifteen-year monthly mean climatologies suggest considerable associations among ocean biogeochemical indices and cloud properties, which is more conspicuous during summer monsoon. Increase in sea salt flux appears to account for the higher values of R_e in June–July over the basin due to strong monsoon wind. Inverse relations between chlorophyll-a and R_e are indicative of smaller droplets that resulted from new particles formed from and/or facilitated by marine biogeochemical emissions. Decline in new particle production due to decrease in surface chlorophyll-a and the growth of particles facilitated by increase in warming, seem responsible for increase in R_e and decrease in CDNC from 2001 to 2015. Using chlorophyll-a as the main proxy for ocean biogeochemical indices, we demonstrated that connections between ocean biogeochemistry and clouds are sustained in both small and large scales in space and time over the Arabian Sea.

了解海洋生物地球化学和云特性之间的关系将有助于规划必要的实验，以了解海洋和大气相互作用之间的联系背后的机制和过程。在这里，我们探索了一个地区的海洋生物地球化学和云特性之间的关联，该地区分别在冬季和夏季季节性地经历了污染和原始大气条件。海洋表面叶绿素的影响一个和生物地球化学通量云性质（云有效半径（（海盐，二甲基硫化物和在海喷雾有机级分）- [R _ë），云光学厚度，并且云滴数浓度（CDNC)) 使用 MODIS（Terra，Collection 6，L3）2001 年至 2015 年的月度数据以及再分析信息进行研究。我们在时间（每月、季节性和每年）和空间（沿海、开放和总（盆地）阿拉伯海）上采用了气候平均方法。这种方法用于最大程度地减少由于各自边界层中的不同动态引起的时空滞后引起的海洋和云属性之间的不相容性（如果有的话）。在每月的手段的趋势表明，在减少叶绿素一和CDNC，而[R _é在2001 - 2015年增加了阿拉伯海盆。流域尺度的变异性（表示为每个月的标准偏差，SD）超过了叶绿素a各月的平均值，而它几乎是CDNC平均值的一半。与 2001-2010 年相比，2011-2015 年温暖的 2011-2015 年期间R _e的增加似乎更容易促进，这与CDNC的减少相吻合。15 年月平均气候表明海洋生物地球化学指数与云特性之间存在相当大的关联，这在夏季风期间更为明显。由于强烈的季风，海盐通量的增加似乎是 6 月至 7 月流域上较高的R _e值的原因。叶绿素a和Re _{e 的}反比关系表示由海洋生物地球化学排放物形成和/或促进的新颗粒产生的较小液滴。下降新的粒子的生产，由于在表面叶绿素减少一个，并通过增加预热促进颗粒的生长，似乎负责增加ř _ë在和减小CDNC从2001年至2015年使用叶绿素一个作为用于海洋主代理生物地球化学指数，我们证明了海洋生物地球化学和云之间的联系在阿拉伯海的空间和时间的小尺度和大尺度上都是持续的。