Tag Archives: Earth science

Simulating the Hadley Cell using Energy2D

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Although it is mostly used as an engineering tool, our Energy2D software can also be used to create simple Earth science simulations. This blog post shows some interesting results about the Hadley Cell.

The Hadley Cell is an atmospheric circulation that transports energy and moisture from the equator to higher latitudes in the northern and southern hemispheres. This circulation is intimately related to the trade winds, hurricanes, and the jet streams.

As a simple way to simulate zones of ocean that have different temperatures due to differences in solar heating, I added an array of constant-temperature objects at the bottom of the simulation window. The temperature gradually decreases from 30 °C in the middle to 15 °C at the edges. A rectangle, set to be at a constant temperature of -20 °C, is used to mimic the high, chilly part of the atmosphere. The viscosity of air is deliberately set to much higher than reality to suppress the wild fluctuations for a somehow averaged effect. The results show a stable flow pattern that looks like a cross section of the Hadley Cell, as is shown in the first image of this post.

When I increased the buoyant force of the air, an oscillatory pattern was produced. The system swings between two states shown in the second and third images, indicating a periodic reinforcement of hot rising air from the adjacent areas to the center (which is supposed to represent the equator).

Of course, I can't guarantee that the results produced by Energy2D are what happen in nature. Geophysical modeling is an extremely complicated business with numerous factors that are not considered in this simple model. Yet, Energy2D shows something interesting: the fluctuations of wind speeds seem to suggest that, even without considering the seasonal changes, this nonlinear model already exhibits some kind of periodicity. We know that it is all kinds of periodicity in Mother Nature that help to sustain life on the Earth.

European scientists use Energy2D to simulate submarine eruptions

The November issue of the Remote Sensing of Environment published a research article "Magma emission rates from shallow submarine eruptions using airborne thermal imaging" by a team of Spanish scientists in collaboration with Italian and American scientists. The researchers used airborne infrared cameras to monitor the 2011–2012 submarine volcanic eruption at El Hierro, Canary Islands and used our Energy2D software to calculate the heat flux distribution from the sea floor to the sea surface. The two figures in the blog post are from their paper.

According to their paper, "volcanoes are widely spread out over the seabed of our planet, being concentrated mainly along mid-ocean ridges. Due to the depths where this volcanic activity occurs, monitoring submarine volcanic eruptions is a very difficult task." The use of thermal imaging in this research, unfortunately, can only detect temperature distribution on the sea surface. Energy2D simulations turn out to be a complementary tool for understanding the vertical body flow.

Their research was supported by the European Union and assisted by the Spanish Air Force.

Although Energy2D started out as an educational program, we are very pleased to witness that its power has grown to the point that even scientists find it useful in conducting serious scientific research. We are totally thrilled by the publication of the first scientific paper that documents the validity of Energy2D as a research tool and appreciate the efforts of the European scientists in adopting this piece of software in their work.

The first Earth science simulation in Energy2D is here: Mantle convection!

It is my goal to make the Energy2D software a powerful simulation tool for a wide audience. Last week I have added some engineering examples and blogged about them.

Last night I came up with an idea for simulating mantle convection, the slow creeping motion of Earth's rocky mantle caused by convection currents carrying heat from the interior of the Earth to the surface. It turned out that the idea worked out.
This blog post demonstrates the first geoscience simulation created using Energy2D. The two screenshots show mantle convection at different times. The streamlines in the second image represent the convective currents. From the simulation, you can see the gradual cooling of the core due to mantle convection--This happens in the time frame of billions of years, but a computer simulation can show it in a few seconds. For simplicity, we don't distinguish the inner core and the outer core in this model. Later, we can build a more complex one that includes these subtle details.

The simulation is available online at: http://energy.concord.org/energy2d/mantle.html. Take a look and stay tuned for more Earth science simulations--brought to you by Energy2D!