Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Seeking Quieter Supersonic Flight
Supersonic flight over the U.S. has been banned by all non-military aircraft for more than fifty years. The ban gained momentum in the 1960s after test programs over St. Louis and Oklahoma provoked public outcry. But NASA’s X-59 aircraft is working to lift the ban by softening the sonic booms that encouraged the ban in…
“Sunny Seaweed Surf”
Seaweed sways in the surf in this photograph by Billy Arthur. I always love how waves look like a stormy sky when viewed from below. This image is extra neat because of the contrast with the sunbeams shining through the still surface on the right side of the image. Sun and storm on the verge…
AI-Based Weather Forecasting Has Blind Spots
Traditional weather forecasting models are physics-based and rely on supercomputers. Practically speaking, this means that they start from the basic governing equations (like the Navier-Stokes equations) and use approximations to model aspects of the problem in order to make the physics solvable, given constraints on time, computational power, spatial resolution, and so on. So-called AI…
Blue Jewels and Gray Haze
Beginning in early spring, brilliant blue ponds form on Greenland’s ice sheets as meltwater gathers in indentations. This satellite image shows the ice east of Nordenskiöld Glacier, which is the tongue of ice projecting on the left side of the image. The center region of ice is darker, marked by soot, ash, and dirt left…
Predicting Volcanic Eruptions
People have long hoped to reliably predict volcanic eruptions. An automated system at Piton de la Fournaise in France has been doing so since 2014 with an impressive 92% accuracy. The tool, called Jerk, makes its predictions based on real-time measurements of subtle ground movements associated with magma fracturing rock on its way to the…
Herring Spawn
From mid-February to early May, tiny silvery Pacific herring gather along the shallow coastlines of Vancouver Island off British Columbia, Canada. In these sheltered waters, they spawn; female fish produce sticky eggs and males flood the area with milt, which turns the water a milky turquoise or green. The colors can be so vivid that…
“Opening the Vortex”
Photographer Lisa K. Kuhn captured a spectacular lenticular cloud over Mount Shasta in this image from the Sony World Photography Awards. These lens-shaped clouds occur most often near mountains and other terrain that forces air to flow up and over it. As the air cools, water condenses out, forming the cloud. When the air flows…
Understanding Pollen Dispersal
When the wind blows, trees shift and sway, reconfiguring their shape and their leaves in response. For parts of the year, that flow can also pluck pollen grains off the tree, carrying them on the winds. A new computational simulation models this pollen dispersal from a tree, with the aim of eventually integrating into a…
Setting the Stripes on a Tiger (Cake)
A tiger skin cake forms a distinctive pattern of light and dark patches as it bakes. Its current popularity seems to have expanded outward from China; I found a lot of Swiss-roll-style recipes that use it as an outer wrapper. Here, researchers look at how the wrinkled surface forms. The viscous batter quickly forms a…
Waves on Other Planets
On Earth, most waves form when wind blows across the water. The shear and added energy from the wind ripples the surface, eventually building up waves (through the Kelvin-Helmholtz instability). The same process should happen anywhere else where wind and open liquid surfaces meet–even on other planets. To explore this, researchers built a new model,…