![]() ![]() But Johnson is one of the few who studies the particular physics of clouds in the laboratory. Many scientists – climatologists, meteorologists and planetary scientists, to name a few – study clouds as part of their broader research. ![]() Like aeronautical engineers using a wind tunnel to observe how currents move around structures, Johnson uses these particles to understand the microphysics that underpin vast and complex systems. Using methods like these, Johnson can study how clouds form and what different cloud particle shapes and compositions can reveal, and she is able to understand the conditions that lead to different cloud types and behaviors. Other methods build upon these to allow the team to look at groups of particles and observe how they scatter and polarize light. These particles are then stable for extended periods of time, which enables long-term research experiments, where the pressure, temperature, electric field and laser illumination may be tweaked, and observations recorded. Johnson and her team use an electric field to levitate and contain the individual particles so that they can’t move around. The particles in Johnson’s lab, like all particles, have a charge. We then watch as that particle grows, shrinks or changes phase with time, which are processes that happen in clouds everywhere.”Ĭlouds on Earth don’t often form without the aid of a nuclei, or a particle, and in some cases what would be considered a nuclei on Earth may be an exotic cloud elsewhere. “Instead, we can take one particle that is representative of a cloud, pump in different gases, and change the temperature and pressure of the system. “Of course, we don’t grow them at quite the same scale you see in an atmosphere,” Johnson said. But the behavior of these lab-based cloud particles mimics the behavior of cloud particles in massive sky-sweeping clouds, only in miniature. Nothing in her lab actually looks like a cloud there are no mists swirling picturesquely in glass bottles. She strips the systems down to their basics to get a clear understanding on how the particles that make up clouds form, develop and interact with their environment. Johnson’s solution is to create her own homegrown clouds to study in her lab in the Department of Earth, Atmospheric, and Planetary Sciences. Studying clouds in their natural environments can be complex and subject to the variations of climate, weather and observation devices. (Purdue University/John Underwood)ĭownload image Clouds in a bottle and a tempest in a teacup Atmospheric scientist Alexandria Johnson uses lasers and controlled environments to study lab-grown versions: particles that behave like miniature clouds and help her explore the physics and microphysics of clouds. Studying clouds in the wild can be challenging. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |