Starting with G: Gale is a strong wind — you'll find it on page 150 — Page 653, Lesson 624

This is the index of the meteorology textbook, so I want to walk you through the entries that start with G, H, I, and J. These are the topics you'll be studying, and I'll give you a quick preview of what each one means so you have the professional terms in mind before we dive into the chapters. Starting with G: Gale is a strong wind — you'll find it on page 150. Then we have Geostrophic Wind, which is a theoretical wind that results from a balance between the pressure gradient force and the Coriolis force; it flows parallel to the isobars, and it's covered on pages 151 and 153. Ghibli is a local wind — a hot, dry, dusty wind from North Africa, found on page 406. Global Climatology is the study of climate patterns across the whole planet, on page 365. Gradient Wind is a more realistic wind model that also accounts for centrifugal force when the wind is curving around pressure systems — that's on page 155. And Gusts are sudden, brief increases in wind speed, on page 150. Moving to H: Harmattan is another local wind — a dry, dusty trade wind that blows from the Sahara toward the Gulf of Guinea, on pages 411 and 415. Haze is a suspension of very small dry particles in the air that reduces visibility, on page 267. Height is a fundamental measurement in meteorology — the vertical distance above a reference level, on page 131. Hill Fog is fog that forms when moist air is forced to rise over a hill and cools to saturation, on page 269. Hoar Frost is a deposit of ice crystals that forms when water vapour deposits directly onto a surface that is below freezing, on page 288. Humidity is the amount of water vapour in the air, on page 75. Humidity Mixing Ratio is a precise measure of that water vapour — the mass of water vapour per unit mass of dry air, on page 78. Hurricane is a tropical cyclone with sustained winds of 64 knots or more, on pages 150 and 424, and there's a broader section on Hurricanes on page 350. Hygrometer is the instrument used to measure humidity, on page 81. Now I: Ice Fog is a fog composed entirely of ice crystals, which occurs at very low temperatures, on page 272. Icing is the accumulation of ice on an aircraft surface, on page 283. Icing Intensity Criteria are the standards used to classify how severe that ice accumulation is — trace, light, moderate, or severe — on page 292. Insolation is the incoming solar radiation received at the Earth's surface, on pages 59 and 167. International Standard Atmosphere, or ISA, is a reference model of temperature, pressure, and density with altitude, used as a baseline for performance calculations, on pages 6 and 9. Intertropical Convergence Zone, or ITCZ, is the belt of low pressure near the equator where the trade winds from both hemispheres meet, on page 308. Inversions are layers in the atmosphere where temperature increases with altitude instead of decreasing, on page 63. ISA Deviation is the difference between the actual temperature and the ISA standard temperature at a given pressure altitude, on page 8. ISOBAR is a line on a weather chart connecting points of equal atmospheric pressure, on page 23. And ITCZ is the abbreviation for the Intertropical Convergence Zone, also referenced on pages 383 and 415. Finally, J: Jet Streams are narrow, fast-moving ribbons of strong wind in the upper atmosphere, typically at altitudes around 30,000 to 40,000 feet. The index entry cuts off, but you'll find them later in the book. These are all the terms you'll encounter in the G through J sections of the index. Each one is a building block for understanding the atmosphere as a pilot.