Experience Being Inside a Cloud Through Fog

The ethereal beauty of clouds drifting across the sky earned them a reputation as the gods' vehicle of choice. In various mythologies, gods arriving on clouds is a common theme, based on the belief that clouds are dense enough to bear their weight. Today, we travel by plane. Yet we still can't help but wonder what it would be like to climb on a cloud and feel its touch. Fortunately, we don't need to go that far. We can access this feeling through fog, as fog is literally a cloud at ground level.

Fig. 1. An artistic interpretation of ancient belief that clouds could support weight.

What are clouds?

From the ground, clouds seem much denser than they actually are because our perception compresses their depth. Despite resembling thick layers of cotton, clouds really are just collections of tiny water droplets suspended in the air. You can say that you are inside the cloud when you're in a bathroom filled with vapor, though the temperatures at cloud altitudes are significantly lower.

For a more authentic experience, walk through the fog. The water droplets will wet your clothes and reduce visibility, but they won't impede your movement, let alone support your weight. Airplanes passing through clouds remain unaffected despite their high speed. The droplets are so minuscule and widely spaced that clouds behave almost like clear air. Any extra resistance from striking the droplets is negligible compared with normal aerodynamic drag.

Fig 2. A passenger aircraft descends through fog toward an illuminated runway.

Winter clouds

In cold weather, water droplets in the clouds turn into tiny ice crystals. To experience winter clouds, we must walk through ice fog. Ice fog is a rare natural phenomenon because it requires unique conditions: temperatures below -20 F (-30 C) along with very high humidity.  Predominantly found in polar regions, it can look stunning in sunlight, but it's uncomfortable to breathe in. Ice fog is responsible for such spectacular atmospheric phenomena as luminous pillars, halos, and sundogs.

Fig 3 Ice fog in Alaska, noon, -40 F (-40 C). Source: Reddit.

Is there a difference?

The difference is in thickness and altitude. Slallow fog is supported by the ground, whereas clouds form high above the ground and expand further vertically. This makes clouds subject to atmospheric instability. Within both, warmer air rises, and cooler air descends, generating interacting air currents that lead to pressure variations and turbulence. However, these effects are more pronounced in clouds, particularly those extending across a wide range of altitudes.

The towering cumulonimbus clouds, which can grow up to 18 km (11 miles) in height, are the most affected. The air currents within them are so strong that they generate electric charges. Pilots steer clear of these clouds at all costs. Inside those clouds, we would be tossed by powerful counterflows, pelted by large hail, deafened by thunder, scorched by lightning, and, in some cases, even twisted by a tornado.  This is certainly a far cry from a stroll in a fog.

Falling through a thin cloud

Thin clouds, however, resemble fog to a high degree, except we fall through them, not walk. Skydivers describe this experience like falling through clear air, with the added challenges of reduced visibility and getting wet. In 12 seconds after a jump, they reach a terminal velocity of about 120 mph (190 km/h), so we would have to pass through fog at that speed to more closely match the cloud experience. Alternatively, you can watch this spectacular video in the comfort of your home.

https://youtu.be/zTg-5pWwhDY?si=GulEx620il6WE63R

Fig. 4. Falling through the clouds by Steve Rivello.