6.3: Accessible Descriptions

Figure 5.1: The Blue Marble

A full-disk color photograph of Earth as seen from space against the black background of space. The entire sunlit hemisphere of the planet is visible, with Africa centered in the image and the Indian Ocean occupying much of the right half. The photograph is commonly known as the "Blue Marble." The globe fills most of the image and is nearly circular. The surrounding background is completely black, with no visible stars.

The visible continents include:

• Africa occupies the center of the image. The Sahara Desert dominates northern Africa with light tan and reddish-brown colors. Central Africa appears darker green and brown beneath extensive white cloud cover. Southern Africa narrows toward the Cape of Good Hope.
• The Arabian Peninsula is visible northeast of Africa as a large tan landmass. The Red Sea forms a narrow blue strip separating northeastern Africa from the Arabian Peninsula.
• Madagascar appears as a large island off the southeastern coast of Africa.
• Portions of southern Europe and southwestern Asia are visible near the upper edge of the globe, although they are partly obscured by the curvature of Earth.

The oceans are a deep blue:

• The Indian Ocean occupies much of the right side of the image.
• The South Atlantic Ocean lies to the left of Africa.
• The Southern Ocean surrounds Antarctica near the bottom of the globe.

White clouds cover large portions of both land and ocean:

• A broad band of broken clouds stretches across central equatorial Africa.
• Numerous long, curved cloud bands spiral across the Southern Hemisphere oceans. Several of these form large comma-shaped weather systems characteristic of mid-latitude cyclones.
• Smaller cloud clusters are scattered across the tropical Indian Ocean and South Atlantic.
• Thin streaks of cloud trace atmospheric circulation over the oceans.

Near the bottom of the globe, Antarctica appears bright white due to its extensive ice and snow cover. Much of the continent is partially hidden by the curvature of Earth and overlying clouds, but its broad ice-covered surface forms a bright white cap along the southern edge of the planet. The image shows the contrast between Earth's major surface features:

• Blue oceans cover most of the visible hemisphere.
• Brown and tan deserts dominate northern Africa and the Arabian Peninsula.
• Darker vegetated regions appear across central and southern Africa.
• Bright white clouds and polar ice provide strong contrast against both land and sea.

Figure 5.1.1 The Water Cycle

A colorful, labeled diagram titled “The Water Cycle” shows how water moves through the environment in a continuous loop. The scene is divided into three main areas: a large body of water on the left, land with vegetation and a river in the center, and mountains on the right.

• At the top left, a bright yellow sun labeled “solar radiation” shines over a blue ocean or lake. Red upward arrows rising from the water indicate evaporation, where liquid water turns into vapor and rises into the air. A large curved arrow shows this vapor moving upward into clouds.
• In the upper middle and right portions, white clouds are labeled condensation, indicating that water vapor cools and forms cloud droplets. Orange arrows labeled “transportation” show wind moving the clouds from left to right across the sky.
• On the right side, above a mountain range, clouds release precipitation, shown as white streaks falling downward as rain or snow. On the mountain slopes, arrows labeled snowmelt runoff show melting snow flowing downhill.
• At ground level, water moves across the land as surface flow, shown by arrows following a river that runs from the mountains toward a lake or ocean. Some of this water seeps into the soil (infiltration) and moves deeper underground through percolation. Beneath the surface, a horizontal arrow labeled groundwater flow shows water moving through underground layers.
• Vegetation in the center of the image includes a tree with roots extending into the soil. An upward arrow labeled plant uptake shows water being absorbed by roots. Additional red upward arrows above plants indicate transpiration, where plants release water vapor back into the atmosphere. Near the mountains, red upward arrows labeled sublimation indicate that ice and snow turn directly into vapor without first becoming liquid.

Overall, arrows throughout the diagram connect these processes, illustrating a continuous cycle: water evaporates, condenses into clouds, is transported by wind, falls as precipitation, and returns to bodies of water through runoff, infiltration, and groundwater flow before repeating the cycle.

Figure 5.1.2 Phase Changes of Water

A simple diagram illustrates changes between the three states of water: solid, liquid, and gas.

• On the left, a large white snowflake icon labeled “ice” represents the solid state. In the center, a cluster of light-blue water droplet shapes represents liquid water. On the right, a group of small, light-blue circles represents water vapor (gas).
• Two large curved blue arrows connect the three states in a loop. The top arrow curves from the ice (left) across the top of the image to the gas (right), indicating a transition directly from solid to gas (sublimation). The bottom arrow curves from the gas (right) back to the ice (left), indicating the reverse process (deposition).
• Although not explicitly labeled, the central liquid state lies between the solid and gas states, visually suggesting the typical transitions: melting (solid to liquid), freezing (liquid to solid), evaporation (liquid to gas), and condensation (gas to liquid).

Overall, the diagram shows that water can move between solid, liquid, and gas states, including both direct transitions and those that pass through the liquid phase.

Figure 5.1.3 Global Water Vapor Concentrations

A global map shows the distribution of atmospheric water vapor across Earth using a flattened, oval (world) projection. The continents are outlined in bright magenta, while the oceans and atmosphere are displayed in shades of gray.

• The background is black, with the Earth centered as a wide oval. North and South America appear on the left side of the oval, Europe and Africa near the center, and Asia and Australia on the right. Antarctica stretches along the bottom edge. Coastlines and land boundaries are highlighted in magenta, making the continents' shapes clearly visible against the grayscale background.
• Across the entire map, swirling patterns in varying shades of gray represent the concentration and movement of water vapor in the atmosphere. Lighter gray and white areas indicate higher moisture concentrations, forming cloud-like bands and spirals, especially over tropical regions and across large ocean areas. Darker gray regions indicate drier air, commonly seen over deserts or certain ocean regions.
• Long, curved streaks and spiral formations suggest large-scale weather systems, such as storm tracks and atmospheric circulation. Bands of moisture are visible near the equator, while more fragmented, swirling structures appear in mid-latitude regions.
• At the top of the image, small text reads “water vapor composite,” with a specific date and time (April 26 at 21:00 UTC). Additional small text and numbers appear along the bottom edge, likely indicating timestamps or data-source information.

Overall, the image visualizes global atmospheric moisture patterns at a specific moment in time, highlighting how water vapor is distributed and transported around the planet.

Figure 5.2.1 Global Ocean Currents Map

This image is a world map in a Robinson projection, showing the major ocean currents worldwide. Landmasses are shaded in light tan, while oceans are light blue-gray. The map includes latitude lines at approximately 60° North, 30° North, the Equator (0°), 30° South, and 60° South.

Ocean currents are illustrated using arrows:

• Red arrows indicate warm currents
• Blue arrows indicate cold currents
• Black arrows indicate general surface current flow directions

Overall Pattern

The map highlights large circular current systems, called gyres, in the Atlantic, Pacific, and Indian Oceans. These gyres rotate:

• Clockwise in the Northern Hemisphere
• Counterclockwise in the Southern Hemisphere

There is also a continuous eastward current encircling Antarctica called the Antarctic Circumpolar Current.

Atlantic Ocean Currents

In the North Atlantic:

• The Gulf Stream (warm, red) flows northeast from the southeastern United States toward Europe.
• The North Atlantic Drift continues this flow toward northwestern Europe.
• The Norwegian Current carries warm water further north.
• The Labrador Current (cold, blue) flows south along the eastern coast of Canada.
• The Canary Current (cold) flows south along the northwest coast of Africa.
• Near the equator, the North Equatorial Current flows westward, while the Equatorial Countercurrent flows eastward.

In the South Atlantic:

• The Brazil Current (warm) flows south along the eastern coast of South America.
• The Benguela Current (cold) flows north along the southwest coast of Africa.
• The South Equatorial Current flows westward.
• The gyre closes with eastward flow in the Southern Ocean.

Pacific Ocean Currents

In the North Pacific:

• The Kuroshio Current (warm) flows north along the coast of Japan.
• The Oyashio Current (cold) flows south from the Bering Sea.
• The California Current (cold) flows south along the U.S. West Coast.
• The North Pacific Current flows eastward across the ocean.
• The North Equatorial Current flows westward, with an eastward Equatorial Countercurrent.

In the South Pacific:

• The East Australian Current (warm) flows south along Australia’s east coast.
• The Peru (Humboldt) Current (cold) flows north along South America’s west coast.
• The South Equatorial Current flows westward.
• These currents form a counterclockwise gyre.

Indian Ocean Currents

• The Agulhas Current (warm) flows south along the southeast coast of Africa.
• The Mozambique Current (warm) flows south through the Mozambique Channel.
• The West Australian Current (cold) flows north along Western Australia.
• The South Equatorial Current flows westward.
• A seasonal North Equatorial Countercurrent flows eastward near the equator.

Southern Ocean

• The Antarctic Circumpolar Current flows continuously from west to east around Antarctica.
• Just north of it, the Antarctic Subpolar Current flows in the opposite direction (east to west).

Figure 5.2.2 Average monthly temperatures for San Francisco, CA, and Richmond, VA

This image is a line chart titled “Average Monthly Temperature.” It compares average temperatures across all twelve months for two cities: San Francisco, California, and Richmond, Virginia.

Chart Structure

• The horizontal (x) axis shows months from January through December.
• The vertical (y) axis shows temperature values ranging approximately from 45°F to 95°F.
• Two lines represent the cities:
  • Blue line: San Francisco, CA
  • Orange line: Richmond, VA
• A legend at the bottom identifies these lines by color and city.

San Francisco Temperature Pattern (Blue Line)

San Francisco shows mild, stable temperatures year-round:

• Starts at about 58°F in January
• Gradually rises to around 67°F in June
• Slight dip in July (~66°F)
• Peaks at about 70°F in September and October
• Declines back to about 58°F in December

Overall, the variation is small, staying roughly between 58°F and 70°F throughout the year.

Richmond Temperature Pattern (Orange Line)

Richmond shows greater seasonal variation with hot summers and cool winters:

• Begins at about 47°F in January
• Gradually increases to 60°F in March
• Warms rapidly to 72°F in April and 80°F in May
• Peaks at approximately 91°F in July
• Slightly decreases to 88°F in August
• Drops to 83°F in September and 70°F in October
• Falls further to about 60°F in November and 53°F in December

Temperatures range widely, from about 47°F to 91°F.

Figure 5.2.3 Average monthly temperatures for Long Beach, CA, and Dallas, TX

This image is a line chart titled “Average Monthly Temperature.” It compares the average monthly temperatures for Long Beach, California and Dallas, Texas across the full year.

Chart Structure

• The horizontal (x) axis lists the months from January through December.
• The vertical (y) axis shows temperature values ranging approximately from 50°F to 100°F.
• Two lines represent the cities:
  • Blue line: Long Beach, CA
  • Orange line: Dallas, TX
• A legend at the bottom identifies each line by color and city.

Long Beach Temperature Pattern (Blue Line)

Long Beach shows a mild coastal climate with moderate seasonal variation:

• Starts around 69°F in January
• Slight dip to about 68°F in February
• Gradually rises to 73°F in April and May
• Continues warming to about 77°F in June
• Peaks around 82°F in July and 84°F in August and September
• Declines to 80°F in October, 74°F in November, and 67°F in December

Temperatures remain within a relatively narrow range of about 67°F to 84°F.

Dallas Temperature Pattern (Orange Line)

Dallas shows a continental climate with hot summers and cooler winters:

• Begins near 57°F in January
• Increases steadily to 61°F in February and 71°F in March
• Continues rising to 78°F in April and 85°F in May
• Climbs sharply to 94°F in June
• Peaks around 97°F in July and 98°F in August
• Drops to 92°F in September
• Falls significantly to 80°F in October, 68°F in November, and 60°F in December

Temperatures vary widely, from about 57°F to 98°F.