Tropical meteorology refers to the study of the atmosphere within the tropics - a roughly-defined area straddling the Tropic of Cancer and Capricorn at latitudes of 23.4N and 23.4S respectively. In particular, it explores an assortment of fascinating tropical phenomena, the most prominent of which being tropical cyclones, and the key mechanisms that fuel today’s tropical landscape. Harnessing immense power and unparalleled ferocity, the main hallmarks of tropical cyclones are their extreme wind speeds upwards of 300 kilometers per hour. Wind, in itself, is a fundamental concept in understanding how such events occur. ![[Pasted image 20240315175935.png]] Convection currents are cyclical motions of a fluid driven by heat and the introduction of a temperature gradient. On average, molecules gain more kinetic energy in tandem with increasing heat, and the resulting greater distance between molecules leads to a lowered density. The heated medium rises, forcefully displacing colder air beneath - and the cycle repeats as colder air is now being heated. Heat transfer in liquids and gasses mainly occurs in this manner, and continues until heat is evenly dispersed. When it comes to studying the atmosphere, this concept is instrumental, and is the primary cause of wind currents on our planet. In the tropics, this carries major implications on what we observe today, and directly contributes to two main atmosphere phenomena - Hadley cells and jet streams. ![[Pasted image 20240315134553.png|700]] In layman’s terms, Hadley cells are massive convection currents that span thousands of kilometers in height and length. The necessary temperature gradient is induced by the difference in proximity to the Sun from varying latitudes - low-latitude areas near the Equator naturally receive more solar energy than areas further north or south. Air rises near the Equator due to atmospheric heating via solar radiation, and rushes either north or south, displacing colder air downwards and towards the equator. This massive migration of air is Earth’s way of distributing heat and maintaining stability, and this carries massive implications on our climate. ![[Pasted image 20240315134533.png|700]] Accompanied by the Coriolis effect, Hadley cells involve the generation of trade wind belts. As the Earth rotates on its axis from west to east every day, wind is deflected off the equator in either direction. This creates permanent wind currents that blow east to west in the equatorial region (marked yellow and orange in the diagram). This knowledge is centuries old as sailors have used these winds to travel between continents in the past. ![[Pasted image 20240315134443.png|700]] Along with this, it is important to remember that this takes place on either side of the Equator, and that there are many existing Hadley cells in close proximity to one another. The area where they meet - roughly around the Equator - is where the heated air rises. Subsequent condensation at higher altitudes as it cools leads to the formation of towering clouds that extend for large stretches of the Equator, forming an expansive area of low pressure and weak winds. ![[Pasted image 20240315134512.png|700]] Why do flights last longer in one direction than the other despite similar distances and routes? Hadley cells along with their sub-tropical counterparts, Ferrel cells, are largely responsible for this. Deflected by the Coriolis effect, air between both cells is “trapped” and begins to flow along the boundaries of the two cells at incredibly high speeds exceeding 450 kilometers per hour from west to east. Pilots, using real-time information and projections in the magnitude and directions of jet streams, articulate specific routes that utilize these streams to maximize efficiency and minimize costs. --- # About the Author <div style="border: 3px solid Lime; padding: 12px; display: flex;"> <!-- align right --> <div style="height:240px width: 120px align: left;"> <img alt="Profile Picture" style="border: 2px dashed grey"> </div> <!-- actual biography --> <div class="content" style="text-align:right"> <span class="description" style="font-size: 16;"> To the person reading this - it’s a great pleasure having you know something about me! My name is Maxwell and I have an undying obsession with atmospheric science, maths, and geography, having recently also acquired a liking for politics. That isn’t enough to properly describe the person I am, but I typically like to spend my time tracking weather systems, learning or teaching mathematical concepts, browsing various online newspaper articles or watching documentaries covering fascinating world affairs. </span> </div> </div>