Jupiter's Storms

The Great Red Spot

Bands and zones

JavaScript — Jupiter storm calculations

const R_JUPITER = 69911e3;  // m

// Jovian rotation
const T_JUPITER = 9.93 * 3600;  // 9.93 hours
const omega_JUPITER = 2 * Math.PI / T_JUPITER;

console.log(`Jupiter ω: ${omega_JUPITER.toExponential(2)} rad/s`);
// 1.76e-4 rad/s — fastest rotator of all planets

// Equatorial speed
const v_eq = R_JUPITER * omega_JUPITER;
console.log(`Equatorial surface speed: ${(v_eq / 1000).toFixed(1)} km/s`);
// ~12.2 km/s — vs Earth's ~0.46 km/s

// Coriolis parameter at GRS latitude
function coriolisJupiter(lat_deg) {
  return 2 * omega_JUPITER * Math.sin(lat_deg * Math.PI / 180);
}

console.log(`GRS Coriolis: ${coriolisJupiter(22).toExponential(2)} /s`);

// GRS wind comparison
function windComparison(jupiter_kmh, earth_hurricane_kmh = 250) {
  return jupiter_kmh / earth_hurricane_kmh;
}

console.log(`GRS edge winds vs hurricane: ${windComparison(430).toFixed(2)}× stronger`);

// Internal heat balance
function jupiter_heat_balance() {
  const solar_at_jupiter = 1361 / (5.2 * 5.2);  // W/m² ~50
  const albedo = 0.5;
  const absorbed = (1 - albedo) * solar_at_jupiter / 4;  // averaged
  // Internal heat ~ same magnitude as absorbed
  return { absorbed_W_per_m2: absorbed, internal_heat_ratio: 2.0 };
}

console.log(jupiter_heat_balance());

// GRS shrinking
const widths_km = {
  '1880': 40000,
  '1979 (Voyager)': 23000,
  '2000': 20000,
  '2017 (Juno)': 16000,
};
console.log(widths_km);

// Storm rotation period
function rotationPeriod(circumference_km, wind_speed_kmh) {
  return circumference_km / wind_speed_kmh / 24;  // days
}

console.log(`GRS rotation: ${rotationPeriod(50000, 350).toFixed(1)} days`);

Why Jupiter's storms matter

• Atmospheric science. Largest, longest-lasting storms — extreme test of meteorological theories.
• Comparative planetology. How storms differ on different gas giants.
• Energy transport. Internal heat drives circulation; lessons for fusion.
• Education. Iconic feature visible in any telescope — accessible astronomy.
• Mission targets. Juno (2016+), Europa Clipper (2024+) study Jupiter atmosphere.
• Exoplanet inferences. Hot Jupiters likely have similar atmospheric features.
• Climate dynamics. Stable storms vs Earth — storms decay quickly. Why?

Common misconceptions

• Jupiter has a solid surface. NO — gas all the way down to liquid hydrogen, then metallic hydrogen near core. No "ground" to land on.
• Storms last forever. Even GRS is shrinking; eventually may dissipate.
• Color comes from sunlight. Color from chemicals (chromophores) — sulfur, phosphorus compounds. Not just solar reflection.
• Bands are static. Active circulation; bands change appearance over decades.
• Jupiter is just a giant Earth. Different physics — gas giant, no surface, no plate tectonics, hydrogen-helium dominant.
• GRS is south-spinning hurricane. Anticyclonic — opposite rotation to Earth hurricanes.