If you’ve ever been on a plane, you’ve seen cloud tops—those fluffy, white formations with hints of gray. But understanding what’s happening inside those clouds has puzzled scientists for years. A breakthrough from Brookhaven National Laboratory in Long Island, New York, is changing that.
Researchers there developed a new type of lidar, a laser-based tool that gives us incredibly clear details about cloud structures. It captures images at an amazing resolution of about 0.4 inches. This makes it 100 to 1,000 times clearer than traditional methods. In a recent study published in the Proceedings of the National Academy of Sciences, they combined this lidar with special lab experiments.
This research is the first to closely examine both the water structures in cloud tops and their interiors. These structures are crucial for understanding how clouds evolve, produce precipitation, and influence Earth’s climate. As Fan Yang, the lead author of the study, put it, the lidar acts like a “microscope for clouds.”
The lidar works by detecting and counting individual photons—particles of light—emitted from clouds when hit with bursts of laser light. A unique algorithm then turns these signals into detailed cloud profiles. The team tested their lidar in a cloud chamber at Michigan Technological University, where they could create clouds under controlled temperature and humidity conditions.
What they discovered was surprising: existing models did not accurately describe cloud physics. The lidar showed that cloud droplet distribution at the top varies greatly, while further down, it remains more uniform.
This inconsistency seems to stem from two main processes: entrainment and sedimentation. Entrainment pulls in drier air from above the cloud, causing uneven droplet distribution at the top. Sedimentation sorts droplets by size, making larger ones fall faster. The interior of the cloud, which experiences more turbulence, has its droplets mix evenly.
Yang pointed out that many atmospheric models either ignore droplet sedimentation or oversimplify how droplets behave. While this is fine for the bulk of clouds, the upper regions, where turbulence is weaker, require a more nuanced approach.
These findings could have significant impacts on atmospheric science. Inaccuracies in how we model cloud tops can lead to unreliable predictions about how clouds reflect sunlight or trigger rainfall. The researchers hope that with further development, this lidar technology could be used to directly measure real clouds in the atmosphere, refining our understanding of weather patterns.
In today’s world, where climate change is a pressing issue, better cloud models could help scientists make more accurate predictions. Understanding clouds could be beneficial for everything from agriculture to disaster preparedness.
Ultimately, this research represents a significant step toward unraveling the complex nature of clouds, giving us new insights into weather forecasting and climate dynamics.
For more details on this study, you can check out the original report in the Proceedings of the National Academy of Sciences here and learn more about the research from Brookhaven National Laboratory.
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