EAGER: Marine Sky Brightening: Prospects and Consequences

太阳地球工程的讨论主要集中在平流层硫酸盐气溶胶和海洋云增亮。然而，这两种太阳地球工程方法在可实现的气候范围、潜在的副作用和不确定性方面都必然有局限性。研究太阳地球工程的其他方法对于扩大社会在应对气候变化方面的选择至关重要。海洋天空增亮(MSB)的研究有可能从根本上改变有关太阳地球工程的论述，并开辟迄今为止研究不足的新研究途径。海洋天空亮化(MSB)是一种将海盐粒子注入海洋边界层的太阳地球工程方法。与海洋云增亮(MCB)一样，海洋云增亮(MCB)是一种相关的地球工程技术，MSB将使云变亮，增加反照率，并使地球降温。然而，对MSB的初步模拟研究表明，海盐气溶胶直接散射产生的辐射强迫可能与云变亮引起的辐射强迫具有相似的量级。此外，尽管MSB在施加辐射强迫方面可能不如MCB有效，但它可能不那么依赖于当地的气象条件：并不是所有的云都可以变亮，而且一些可能需要降温的地区没有云。该项目包括在一系列模型中对MSB进行系统的探索，包括用于了解散射的最佳颗粒尺寸的辐射传输模型、用于了解边界层动力学和局部气候影响的区域模型和大型涡流模拟器。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Solar geoengineering discussions have largely focused on stratospheric sulfate aerosols and Marine Cloud Brightening (MCB). However, both of these methods of solar geoengineering necessarily have limits in terms of their ranges of achievable climates, their potential side effects, and their uncertainties. Studying other methods of solar geoengineering is essential for expanding the options available to society for addressing climate change. Studies of Marine Sky Brightening (MSB) have the potential to fundamentally alter discourse about solar geoengineering, as well as open up new avenues of research that have been heretofore under-studied. This project is focused on MSB.Marine Sky Brightening (MSB) is a proposed method of solar geoengineering whereby sea salt particles are injected into the marine boundary layer. Like Marine Cloud Brightening (MCB), a related geoengineering technique, MSB would brighten clouds, increasing albedo and cooling the planet. However, preliminary modeling studies of MSB have shown that radiative forcing from direct scattering by the sea salt aerosols can be of a similar magnitude to radiative forcing from cloud brightening. Moreover, although MSB may be less efficient than MCB at exerting radiative forcing, it may not be as dependent upon local meteorological conditions: not all clouds can be brightened, and some areas that may be desirable to cool don't have clouds. This project includes a systematic exploration of MSB in a hierarchy of models, including radiative transfer models to understand optimal particle size for scattering, regional models and large eddy simulators to understand boundary layer dynamics and local climate effects.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.