The atmosphere is a chaotic place shaped by constantly shifting energy, motion, and global weather patterns that influence conditions across the planet. Meteorologist Lewis Fry Richardson once summed it up this way:
“Big whirls have little whirls,
That feed on their velocity;
And little whirls have lesser whirls,
And so on to viscosity.”
And that pleasantly details the energy cascade that runs through the atmosphere and other fluid bodies.
This blog post lays out a small but mighty conceptual toolkit for understanding some of the large-scale global interactions (known as teleconnections) that shape our day-to-day weather, along with the observation platforms that let us see them.
Eulerian and Lagrangian Perspectives
For starters, let’s establish the two primary reference frames used in atmospheric science: Eulerian and Lagrangian.
Through an Eulerian framework, we observe the atmosphere as it passes by from a fixed position. Instruments such as Doppler wind LiDARs, weather stations, geostationary satellites, and fixed buoys operate in this way.
By contrast, Lagrangian reference frames literally “go with the flow” and follow the fluid as it is churned about. Instruments like weather balloons, drifting buoys, and dropsondes released by hurricane hunters all operate this way. There’s also work that uses smoke or steam plumes to characterize the lower levels of the atmosphere.
Advection and Atmospheric Motion
Now, imagine you’re sitting on your porch one evening as a windy cold front rolls through. You can feel the temperature drop by 10 degrees over an hour, but no single air parcel actually cooled. The preexisting warm air was displaced by the denser cold air.
This is advection: the horizontal movement of fluid. What a fixed sensor (you) records is the sum of how the atmosphere itself is evolving, and what the wind is dragging in from upstream.
Once you start thinking in terms of advection, the atmosphere stops looking like a chaotic map and starts looking more like a conveyor belt. Many of the global weather patterns we experience every day are ultimately driven by this large-scale movement of energy and air. The question then becomes: what’s driving the conveyor belt?
How Global Weather Patterns Form
At the largest scale, the answer is heat and a rotating planet.
The tropics receive far more solar radiation than the poles, and combined with Earth’s rotation, that imbalance drives regular circulation cells and concentrates fast winds into the jet stream.
The atmosphere and ocean spend most of their energy budget moving warm air poleward and cold air equatorward.
Figure 1 – Schematic of a midlatitude jetstream with trough and ridges
If Earth didn’t rotate, heat transport would look relatively simple: warm air would rise at the equator, drift toward the poles, sink, and return along the surface. One giant overturning cell per hemisphere.
But because Earth rotates, that rotation deflects moving air through a phenomenon we call the Coriolis effect. As a result, poleward flow bends eastward and concentrates into fast west-to-east currents in the upper troposphere, as shown in Figure 1.
Figure 2 shows a more complete picture with three stacked circulation cells in each hemisphere: Hadley cells near the equator, Ferrel cells in the mid-latitudes, and Polar cells near the poles. Each of these cells contributes to transporting heat, and they are separated by associated jet streams.
Together, these circulation features help create the global weather patterns that influence temperature, precipitation, and storm development across entire continents.
Observing Global Weather Patterns
We’re able to infer all of this because of numerical weather models informed by the instruments we mentioned earlier: radiosondes profiling the jet stream twice a day worldwide, satellites watching cloud bands, and buoy networks measuring sea-surface temperatures.
No single platform tells the full story. Large-scale atmospheric dynamics only emerge when we stitch together observations from multiple systems operating across different spatial and temporal scales.
At Wet Dog Weather, we work with models that transform these observations into a coherent platform providing model output across a wide range of temporal and spatial resolutions. The animation below shows GFS high cloud cover rendered through our platform.
Connecting the Bigger Picture
The atmosphere may look chaotic at first glance, but beneath that complexity lie organized systems that constantly move heat, moisture, and momentum around the globe. From advection and jet streams to circulation cells and observation platforms, each piece contributes to a much larger interconnected system.
Understanding global weather patterns helps connect local weather events to the broader atmospheric processes unfolding across the planet. In an upcoming blog post, we’ll explore how these large-scale interactions evolve during El Niño events and what they can mean for weather conditions across regions worldwide.