Notes on Climate Factors and Related Climate Types

Elevation is the height above sea level; as you go higher, air becomes thinner and the climate tends to be cooler.
Rule of thumb provided: temperature decreases about $3.5^{\circ}\mathrm{F}$ for every 1000 feet of elevation. This is a commonly cited lapse rate in these discussions; the idea is that higher elevations are cooler.
If you don’t have this written down, add it to your notes: \Delta T \approx -3.5^{\circ}\mathrm{F} \text{ per } 1000\ \text{ft}.$n
Practical implication: mountain regions often have distinct microclimates on windward vs leeward sides due to orographic effects.

Ocean currents influence coastal climates by moving warm or cold water parallel to coastlines.
Warm ocean currents flowing along landmasses tend to heat the adjacent air and land a bit, producing more temperate climates than their latitude would suggest.
Cold ocean currents have the opposite effect, cooling the air and land they pass by.
Examples discussed:
- Near Iceland, a warm ocean current can warm the air above it and modestly warm the land, contributing to a more temperate climate in some areas.
- In contrast, cold currents along coasts can contribute to cooler, drier conditions; the Atacama Desert is given as an example of a cold-current–influenced coast that creates very dry conditions.
The basic takeaway: warm vs cold currents flowing along coastlines can significantly modify regional climate by altering coastal temperatures and moisture availability.

Uneven heating of the Earth’s surface drives the formation of prevailing winds.
Rising warm air creates low pressure; cooler air moves in to replace it.
The basic rule in the transcript: air moves from high pressure to low pressure, and rising warm air forms low-pressure areas.
Global wind belts include:
- Equatorial regions: relatively low pressure (intertropical area) with rising air and heavy rainfall in some zones.
- Subtropical highs: high-pressure belts at roughly 30° N and S.
- Polar highs: high-pressure zones near the poles.
Resulting global wind patterns:
- Trade Winds: low-latitude prevailing winds (named because sailors depended on them for trade routes).
- Westerlies: mid-latitude prevailing winds, blowing from the west.
- Polar Easters: high-latitude prevailing winds, blowing from the east.
In the discussion, storms are often coming from the west (aligned with the Westerlies in the mid-latitudes).
Key connection to climate: these wind patterns influence precipitation distribution and temperature by transporting air masses and moisture.

Latitude determines how much direct sunlight a place receives, which strongly drives climate.
Low latitudes (near the equator): more direct sunlight year-round -> hotter temperatures overall.
Mid latitudes: about six months of direct sunlight and six months of indirect sunlight -> seasonal variation.
High latitudes (toward the poles): sunlight is more indirect, especially in winter, leading to cooler conditions and greater seasonality in some cases.
Practical implication: latitude influences the baseline temperature regime and seasonality of a region.

Mountain ranges and other large landforms can trap, redirect, or enhance air masses, producing diverse local climates on either side of the range.
Windward side (the side facing the prevailing winds):
- Warm, moist air from the ocean is forced to rise as it meets the mountain slope.
- As the air rises, it cools and condenses, leading to condensation and precipitation, often a perpetual rain cycle on this side.
Leeward side (the side sheltered from the wind), also called the rain shadow side:
- After air descends on the leeward side, it compresses and warms, leading to drier and hotter conditions.
- The rain shadow can extend hundreds of miles inland, creating arid or semi-arid conditions away from the windward side.
This landform effect contributes to stark climatic contrasts over relatively short geographic distances.

Common climate on the West Coast of large landmasses in the mid-latitudes (e.g., Seattle; parts of Great Britain).
Key features described:
- Mild, rainy winters and cool to mild summers with persistent precipitation.
- Not a great range in temperatures throughout the year due to the influence of nearby oceans and frequent cloud cover.
- High precipitation totals, leading to soils that are leached and highly acidic.
- Vegetation tends to be mixed forests (deciduous and coniferous trees).
Real-world examples mentioned:
- Seattle climate as a canonical example of marine west coast climate.
- Great Britain as another familiar example.
Practical implications:
- The climate supports specific forest types and agricultural constraints due to soil acidity and consistent precipitation.

Described as the climate typical of areas like Indiana (the instructor’s region) and often contrasted with maritime influence.
Important characteristics discussed:
- Inland location with little maritime influence.
- Temperature range tends to be moderate with noticeable seasonal variation, but not extreme according to the speaker.
- Often divided conceptually into long summers vs. short summers, depending on how long winter lasts in a given area (e.g., Minnesota vs. Indiana).
- The term “continental climate” is associated with interior regions away from the moderating influence of oceans.
In the discussion, continental climates were described as:
- Found in the middle of large land masses in the mid-latitudes.
- Large temperature extremes are more common inland but the speaker notes that in their example the extremes are not as severe as assumed (e.g., hot days and very cold days exist, but not extreme highs or lows all the time).
Practical implications:
- Greater seasonal temperature contrasts than maritime climates.
- Impacts on agriculture and vegetation due to more pronounced seasonal shifts.

Five main factors affecting climate discussed:
- Elevation: temperature drops with height; rule of thumb provided: \Delta T \approx -3.5^{\circ}\mathrm{F} \text{ per } 1000\ \text{ft}$$.
- Ocean currents: warm currents warm coastal zones; cold currents cool them; can create temperate or cooler climates depending on the current.
- Wind patterns: uneven heating drives global wind belts (trade winds, westerlies, polar easterlies); winds influence storm tracks and precipitation.
- Latitude: determines how much direct sunlight a location receives; drives general warmth/coldness and seasonality.
- Landforms: mountains create windward wet and leeward dry zones; rain shadow effects and the range of microclimates.
They connected these concepts to real-world climates and regions (Seattle and Great Britain for marine west coast; Indiana for humid continental).
Ethical, practical implications mentioned: soils on the West Coast are highly acidic due to leaching; this affects agriculture and forest composition; regional climate differences influence land use planning and biodiversity.
Notable clarifications from the discussion:
- The basic atmospheric rule is that air moves from high to low pressure, with warm air rising to form low-pressure regions.
- The lecture uses disposition of winds and pressures to explain how climates are shaped; these patterns are foundational to understanding global climate zones.