Andes Climate Mystery Packet
PAGE 1
World Geography Investigation Unit
Andes Climate Mystery
Solve the puzzle of the world's most extreme mountain climate variations.
Investigator Name:
Date of Analysis:
Geographic Rank:
6th Grade Detective
The Paradox of the Giant Wall
Imagine standing in a place where you can see a freezing, snow-covered peak towering above a dry, sun-baked desert to your left, while a dense, humid rainforest lies just over the mountains to your right. This is not a fantasy world—this is the real-life Andes Mountain Range in South America. Stretching over 4,300 miles along the Pacific coast, the Andes form the longest continental mountain chain on Earth.
What makes the Andes a true climate mystery is how quickly the environment changes. At the mountain base near the equator, it is tropical and warm. Yet, as you climb up, you travel through different climate zones, eventually reaching barren, icy summits where humans can barely breathe. Even stranger, on the western side of the mountains sits the Atacama Desert—the driest place on Earth—while just a short distance eastward across the peaks lies the lush, rain-soaked Amazon Basin. How can one mountain range create such dramatically different worlds so close together?
Resumen en Español (Spanish Summary)
La cordillera de los Andes en Sudamérica es la cadena montañosa continental más larga del planeta. Presenta un misterio climático increíble: en un lado de las montañas se encuentra el Desierto de Atacama (el más seco del mundo), mientras que en el otro lado está la selva húmeda del Amazonas. La altitud extrema, la latitud y la barrera montañosa bloquean la humedad y crean microclimas que van desde el calor tropical hasta cumbres de hielo eterno. Usaremos el marco LACEMOPS para resolver este misterio.
First Impression: Why do you think the climate changes so rapidly when climbing a mountain?
Andes Climate Mystery Unit — Student Packet August 2026
PAGE 2
The LACEMOPS Decoder Key
Every climate on Earth is shaped by these 8 powerful geographic factors. Use this key as your reference guide!
L
Latitude
Distance from the Equator. Places near the equator get direct sunlight and are warm; places near the poles get angled light and are cold.
Key Andes Clue: Warm northern base vs. cold southern tip.
A
Altitude (Elevation)
Height above sea level. As elevation increases, air pressure drops, causing temperatures to decrease (about 3.5°F drop per 1,000 feet).
Key Andes Clue: Glaciers on peaks directly above steaming jungles.
C
Continentality
Distance from the sea. Water holds heat longer than land. Coastal areas have mild, stable temperatures; inland areas have extreme temperature shifts.
Key Andes Clue: The Pacific Ocean is close, but blocked by cliffs.
E
Elevated Barriers
Mountains block rain clouds, forcing air upward where it cools and dumps rain on the windward side, leaving the leeward side dry (Rain Shadow).
Key Andes Clue: The giant mountain wall splits the dry west and wet east.
M
Massive Winds
Prevailing winds distribute heat and moisture. Trade winds blow moist tropical air from the Atlantic Ocean westward toward South America.
Key Andes Clue: Trade winds slam wet air straight into the eastern peaks.
O
Ocean Currents
Rivers of hot or cold water flowing in oceans. Cold currents cool the air above them, making it unable to rise or form rain, creating desert coasts.
Key Andes Clue: Cold Humboldt Current flows right past the desert coast.
P
Pressure Cells
High pressure brings dry, stable weather (sinking air). Low pressure brings warm, rising air that forms storm clouds and heavy precipitation.
Key Andes Clue: Sinking high pressure locks in the Pacific side dryness.
S
Storms
Occasional extreme weather systems (like El Niño) can disrupt normal wind and ocean currents, bringing floods to dry zones and dry periods to wet zones.
Key Andes Clue: El Niño cycles completely flip the coastal climate of Peru.
Andes Climate Mystery Unit — Student Packet August 2026
PAGE 3
Andes Landmarks Evidence File
Every letter of the LACEMOPS framework corresponds to a real geographical feature. Decode all 8 below!
PART A Match the 8 Andes Landmarks to L-A-C-E-M-O-P-S!
Read each real landmark description below. In the box, write the correct LACEMOPS letter (L, A, C, E, M, O, P, or S) that directly explains that landmark's climate condition.
1. Mount Aconcagua Peaks
Glaciers cap this 22,837-foot peak all year, while warm, green plains lie below it.
2. Cold Humboldt Current
Chilled waters from Antarctica flow along the Peru coast, preventing rain cloud formation.
3. Rain Shadow Divide
The 20,000-ft high ridge acts like a wall, locking rain in the Amazon and leaving the coast bone dry.
4. Patagonia vs. Ecuador
Andes peaks in Ecuador near the equator are warm; southern peaks in Chile are subpolar and frozen.
5. Atlantic Trade Winds
Massive easterly wind currents carry humid jungle air from Brazil straight into the eastern slopes.
6. Valparaíso vs. Mendoza
Coastal Valparaíso has mild ocean weather, but inland Mendoza has extreme summer/winter shifts.
7. South Pacific Subtropical High
A giant semi-permanent block of sinking, high-pressure air off Chile squash clouds and blocks rain.
8. El Niño Cycles
Occasional ocean-atmospheric shifts bring warm water and massive flash floods to the dry Atacama desert.
PART B Deciphering the Rain Shadow
Fill in the blanks to complete the Rain Shadow mechanism. Use words: Atacama, Elevated Barrier, windward.
1. Trade winds hit the eastern slopes of the Andes. Because the mountains are a giant , the wind is forced upward.
2. Rising air cools, forms clouds, and dumps heavy rain on the side of the mountain chain (Eastern side).
3. Descending dry wind on the western side lacks moisture, forming the hyper-arid Desert.
Connect the Evidence
Explain how Altitude (A) and Ocean Currents (O) work together to give Peru's coast cold weather and zero rain:
Andes Climate Mystery Unit — Student Packet August 2026
PAGE 4
Climate Analyst Challenge (DOK 1-3)
Test your geographer skills with this three-tier depth-of-knowledge assessment.
DOK level 1: Recall & Identify
1. Which LACEMOPS climate factor is directly responsible for temperatures dropping roughly 3.5 degrees Fahrenheit for every 1,000 feet climbed?
A Latitude B Continentality C Altitude D Massive Winds
DOK level 2: Explain & Analyze
2. Explain the difference between the windward side and the leeward side of the Andes Mountains, specifically why the Amazon Basin is rain-soaked and the Atacama Desert is hyper-arid.
DOK level 3: Synthesize & Predict
3. Imagine a giant geological disaster instantly flattened the entire Andes Mountain Range to sea level. Predict how this would affect the climate of both the Atacama Desert and the Amazon Rainforest. Support your prediction using your LACEMOPS decoder.
Andes Climate Mystery Unit — Student Packet August 2026
Andes Climate Teacher Guide
GUIDE 1
Educator Resources & Pacing Guide
Andes Climate Mystery Teacher Guide
Instructional pathways and scaffolding tips for the 6th-grade LACEMOPS inquiry lesson.
Target Grade 6th Grade (MS-ESS2-5)
Suggested Time 60 - 90 Minutes
Key Framework LACEMOPS Inquiry
Suggested Instructional Pacing
1. The Hook (10 Mins) — The Andes Paradox Have students examine Page 1. Read the reading passage together. Emphasize the paradox: how can a dense jungle and the driest desert exist right next to each other? Let students write their first thoughts in the "First Impression" box.
2. Decoding Framework (15 Mins) — Introducing LACEMOPS Review the 8 variables on Page 2. Introduce the memory device: LACEMOPS. Note that for this lesson, we will focus heavily on **L**atitude, **A**ltitude, **E**levated Barriers, **M**assive Winds, and **O**cean Currents.
3. Cooperative Investigation (20 Mins) — Andes Evidence Log Have students work in pairs or small groups to solve Part A and Part B on Page 3. Encourage them to refer back to the Page 2 decoder to identify which factors explain each mystery scenario.
4. Synthesis & Assessment (15 Mins) — DOK Assessment Students complete Page 4 individually. Use this as a formative assessment to gauge mastery of basic recall (DOK 1), system explanations (DOK 2), and predictive reasoning (DOK 3).
Scaffolding Tips & Common Misconceptions
- Confusing Latitude vs. Altitude: Students often assume peaks are cold because they are closer to the sun. Remind them that air pressure drops as you climb, meaning the air cannot hold heat.
- Bilingual Support: Encourage Spanish-speaking or dual-language learners to use the Spanish summary box on Page 1 to build foundational comprehension before diving into English activities.
- The Rain Shadow Effect: Walk through Part B as a whole class if students struggle to visualize air rising, cooling, and condensing over the mountain peak.
Andes Climate Mystery Unit — Teacher Guide August 2026
GUIDE 2
Official Answer Key & Exemplar Responses
Scoring reference guide for student worksheets and DOK assessments.
Page 3: Part A & B Solutions
Part A: Landmark Matching Key
- • Landmark 1 (Aconcagua): A (Altitude)
- • Landmark 2 (Humboldt): O (Ocean Currents)
- • Landmark 3 (Rain Shadow):
