Our brains are good at finding patterns where none exist. This is why we see a face on the surface of Mars, and it’s the basis of the cloud-watching game that many of us played when we were kids. The changing nature of water vapor condensing in the sky is perfect fodder for finding silhouettes of pirate ships or raging dinosaurs, if you’re willing to let your imagination run wild. It’s even good source of inspiration for SNL sketches.
Cloud watching has most likely been a favored pastime ever since humans have been around and looking up. In most climates, clouds can be counted on to slowly cross the skies, or gather ominously before a storm. However, as climate change progresses, this may change. While humans are good at finding patterns in individual clouds, understanding their long-term patterns and their contribution to the larger climate isn’t as easy.
Getting a decent picture of the world as a whole is relatively easy, while getting the granular data from shifting clouds and other ever-changing high definition processes is tricky. When it comes to modeling climate, it seems we can get big picture or high definition at small scales, but not both. To solve the cloud puzzle, we’re going to need new tools.
Researchers at the University of California, Irvine and their colleagues are working to build new climate models that will give us both the big and small pictures we’ll need to more accurately predict how the climate will change in the future. Their findings were published in the Journal of Advances in Earth System Modeling.
Anthropogenic climate change is radically altering the face of our planet and our ability to live comfortably on it. Seas rise, ecosystems shift and species change or disappear. Above all, the clouds continue to drift lazily, but that may not always be the case. Climate change will most likely leave its mark on the sky, we just don’t know how.
As average global temperatures continue to rise, it is likely that the formation of clouds will be impacted. They could shrivel up and disappear, or they could become even denser and more abundant. Which of these two scenarios is confirmed is of crucial importance for understanding how climate change will evolve in the future. Fewer or thinner clouds would mean more sunlight reaching the planet’s surface and, potentially, faster warming. More and denser clouds would block sunlight, be more reflective, and have the opposite effect of delaying some of the effects of climate change.
The problem is that accurately reproducing cloud formation in our climate models is currently beyond the capability of even our most powerful computers. Instead, climatologists approximate the presence and changing behavior of clouds to make the best guesses. Our current models have a resolution — you can think of it as pixels on a massive planetary screen — of around 4 kilometres. This means that for anything happening at scales less than 4 kilometers, the data just isn’t there. When you save and look at the model as a whole, it looks pretty good, but we’re missing a lot of the granular detail that fuels this image.
In order to get the data that we would really need to know how clouds are going to evolve and contribute to future climate change, we would need a resolution of about 100 meters, about 40 times more definition than what we currently have. Taking current technology trends as a guide, we will eventually get there, but it may be too late for us to put data to good use by then.
The process described in this new document involves running two separate models and getting them to talk to each other. They start with a low-resolution model that looks at the planet at 100 kilometer resolution to get an outline. A second model constructs patches of information at a resolution of 100 to 200 meters. This allows scientists to grasp the complex mechanics at work in cloud formation. The two models then exchange information every 30 minutes to make sure neither of them has strayed too far from reality and is correct.
This allows a supercomputer to use its limited resources more efficiently by dividing the costs between big and small, getting the best of both worlds.
The fate of the clouds, and therefore the rest of our planet, remains unclear, but scientists now have additional tools to glimpse into the future. Hopefully the clouds will part – or thicken – before it’s too late.
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