In the polar regions, high pressure exists due to cold, dense air that sinks at the poles. This creates surface divergence, with air flowing outward from the poles toward lower latitudes, specifically toward the subpolar low near 60°. In the Northern Hemisphere, this poleward-to-equatorward flow is deflected to the right by the Coriolis effect, creating winds that blow from northeast to southwest. These are called the polar easterlies because they blow from the east (northeast).

At 10°N, the location falls within the Northern Hemisphere trade wind belt, not the westerly belt. The common misconception is that all Northern Hemisphere winds are westerly, but this is incorrect. Between 0° and 30°N, the prevailing winds are the northeast trade winds, which blow from northeast to southwest (generally easterly, not westerly). These winds result from air flowing from the subtropical high toward the equatorial low, deflected to the right by the Coriolis effect. Only between 30° and 60°N do the westerlies dominate.

Near 30°N lies the subtropical high pressure belt, not a low-pressure zone. In the idealized global circulation model, air that rises at the equator as part of the Hadley cell moves poleward at altitude and descends near 30° latitude. This descending air creates high pressure at the surface due to the compression and warming of the sinking air mass. The misconception that 30°N should be low pressure because it's warm ignores the dynamics of the Hadley cell circulation, where descent, not surface temperature, determines the pressure pattern.

Global wind patterns show that trade winds at 20°N and 20°S blow toward the equator but curve due to the Coriolis effect rather than flowing straight north-south. The Coriolis effect is caused by Earth's rotation, which creates apparent deflection of moving objects relative to Earth's surface. In the Northern Hemisphere, moving air is deflected to the right, while in the Southern Hemisphere, it's deflected to the left. This deflection prevents winds from flowing directly from high to low pressure and creates the curved wind patterns observed in global circulation.

In the Northern Hemisphere, the Coriolis effect causes air to be deflected to the right of its motion. Around a high-pressure system, air flows outward (diverges) from the center due to the pressure gradient. As this air moves outward, the Coriolis deflection to the right creates a clockwise rotation pattern. Subtropical highs near 30°N are characterized by this diverging, clockwise-rotating surface flow, which helps create and maintain the clear, dry conditions associated with these pressure systems.

Between 0° and 30° latitude, the dominant surface wind belt is the trade winds, which blow generally from east to west (easterly flow). In the Northern Hemisphere, these are the northeast trade winds, while in the Southern Hemisphere, they are the southeast trade winds. Both result from surface air flowing from the subtropical highs near 30° toward the equatorial low, with the Coriolis effect deflecting the flow to create the easterly (east-to-west) surface flow characteristic of the tropical regions.

In the three-cell model, the Ferrel cell is considered thermally indirect because it is not directly driven by heating and cooling like the Hadley and Polar cells. Instead, the Ferrel cell exists primarily due to the mechanical interaction between the adjacent Hadley and Polar cells. The Hadley cell's descending air at 30° and the Polar cell's descending air at the pole create pressure gradients that drive the Ferrel cell circulation, making it dependent on its neighbors rather than direct thermal forcing.

At 60° latitude, warm air from the mid-latitudes meets cold air from the polar regions, creating a boundary called the polar front. The temperature contrast causes air to rise, creating a belt of low pressure called the subpolar low. This rising air and low pressure zone is where westerlies (from the south) meet polar easterlies (from the north), and the convergence and uplift frequently generate cyclonic storms and weather systems.

Earth's rotation creates the Coriolis effect, which deflects moving objects due to the different rotational speeds at different latitudes. In the Southern Hemisphere, the Coriolis effect deflects moving air to the left of its motion direction. This deflection affects all moving air masses and is responsible for the curved wind patterns observed in global circulation, including the direction of trade winds, westerlies, and the rotation direction of storms and pressure systems in the Southern Hemisphere.

At 55°N, the location falls within the Northern Hemisphere westerly wind belt (30°-60°N). The westerlies result from surface air flowing from the subtropical high toward the subpolar low as part of the Ferrel cell circulation. The Coriolis effect deflects this poleward-moving air to the right, creating winds that generally blow from the southwest in the Northern Hemisphere mid-latitudes. Southwest winds are characteristic of the westerlies because they represent the southwest-to-northeast flow pattern created by Coriolis deflection of the pressure-gradient-driven poleward flow.