8.5: Accessible Descriptions

Figure 7.1 Global Atmospheric Circulation Model

A simplified diagram of Earth shows global atmospheric circulation patterns. The globe is centered on the Atlantic Ocean, with the Americas on the left and Europe and Africa on the right. Latitude lines are marked at 0° (Equator), 30° North and South, and 60° North and South. The diagram illustrates how air moves around the planet in three main circulation cells in each hemisphere: Hadley cells, Mid-latitude (Ferrel) cells, and Polar cells.

Key Features and Labels

• The Equator (0°) is marked with a red horizontal line labeled “Intertropical Convergence Zone (ITCZ)”.
• Areas of rising and sinking air are labeled:
  • “HIGH” pressure zones near 30° North and South
  • “LOW” pressure zone near the Equator
• Curved arrows show the direction of air movement both vertically and horizontally.

Circulation Cells

1. Hadley Cells (0° to 30° North and South)

• Warm air rises at the Equator (ITCZ), creating a low-pressure zone.
• This air moves poleward at high altitude.
• Around 30° latitude, the air cools and sinks, forming high-pressure zones.
• Surface air then flows back toward the Equator.

2. Mid-latitude (Ferrel) Cells (30° to 60° North and South)

• Air flows poleward at the surface from 30° to 60° latitude.
• Around 60°, this air rises due to interaction with colder polar air.
• At higher altitudes, air flows back toward 30°.

3. Polar Cells (60° to 90° North and South)

• Cold air sinks at the poles (90°), creating high-pressure zones.
• Surface air flows toward 60° latitude.
• At about 60°, the air rises and returns poleward aloft.

Global Wind Belts

The diagram labels major wind patterns:

• Northeasterly Trade Winds (Northern Hemisphere): Blow from northeast to southwest between 30°N and the Equator.
• Southeasterly Trade Winds (Southern Hemisphere): Blow from southeast to northwest between 30°S and the Equator.
• Westerlies (mid-latitudes): Blow from west to east between 30° and 60° in both hemispheres.

Figure 7.2.4 The Coriolis Force turns the parcel to the right

This labeled diagram illustrates how an air parcel responds to the pressure-gradient force and the Coriolis force in the Northern Hemisphere.

Diagram Structure:

• The image consists of three horizontal lines, each representing a different isobar (a line of equal atmospheric pressure):
  • Bottom Line (Point B): 1016 millibars (mb)
  • Middle Line (Point A): 1012 mb
  • Top Line (Point C): 1008 mb
• The vertical distance between each isobar is labeled as 50 kilometers.
• A northward-pointing arrow on the far left indicates the direction of motion (with north at the top).

• A red circle represents an air parcel starting at Point A (1012 mb).
• The parcel initially moves northward toward lower pressure (Point C) due to the pressure gradient force, which is shown as a thick red upward arrow labeled PGF.
• As the parcel accelerates northward, the Coriolis force (CF) begins to deflect its path to the right, as shown by a blue arrow pointing eastward.
• Three red dots trace the curving path of the air parcel:
  • First directly northward.
  • Then deflected slightly northeast.
  • Finally curving more to the right as the Coriolis force increases.
• The rightward deflection continues until the Coriolis force balances the pressure-gradient force, at which point the parcel moves in a straight line parallel to the isobars, achieving geostrophic balance (not yet fully reached in this diagram).
• A text label on the right side explains: "As the particle accelerates, the Coriolis Effect amplifies, and the particle turns further right."

Figure 7.2.5 Geostrophic Flow is achieved

This is a labeled atmospheric diagram showing the path of an air parcel under the influence of the pressure gradient force and the Coriolis effect, culminating in geostrophic balance.

Diagram Structure:

• The diagram contains three horizontal lines representing atmospheric isobars, or lines of equal pressure:
  • Bottom Line (Point B): 1016 millibars (mb)
  • Middle Line (Point A): 1012 mb
  • Top Line (Point C): 1008 mb
• Vertical spacing between isobars is labeled as 50 kilometers, showing equal pressure intervals from the surface upward.
• On the left side, an upward-pointing arrow labeled "N" denotes North, establishing that the top of the diagram is the direction toward lower pressure.

Air Parcel Motion and Forces:

• A red dot at Point A shows the initial position of the air parcel.
• The parcel moves northward from 1012 mb to 1008 mb due to the pressure gradient force (PGF), represented by a large red arrow pointing straight up.
• As the parcel moves, it is deflected to the right (eastward) by the Coriolis force (CF), shown as a blue arrow pointing rightward.
• The parcel's motion path is illustrated by several sequential red dots that curve from vertical to horizontal.
• Eventually, the parcel reaches a point where the Coriolis force exactly balances the pressure-gradient force, and it begins to move in a straight path parallel to the isobars, indicated by a horizontal black arrow.
• This final condition is labeled with the explanation: "Eventually, PGF = CF, and the particle travels in a straight path, parallel to isobars."

Figure 7.3.2 Global Map of Average Sea-Level Atmospheric Pressure in January

This is a world map in an oval (Robinson-style) projection titled “Average Sea-Level Atmospheric Pressures in January.” It shows how atmospheric pressure is distributed globally in January.

Chart Structure and Legend

• The map displays continents in light tan and oceans in shades of blue.
• A color scale indicates pressure levels in millibars (mb):
  • Dark teal/blue: Over 1,024 mb (highest pressure)
  • Medium blue: 1,016 to 1,024 mb
  • Light blue-gray: 1,008 to 1,016 mb
  • Light tan: 1,000 to 1,008 mb
  • Darker tan/orange: Under 1,000 mb (lowest pressure)
• Letters mark pressure centers:
  • “H” indicates a high-pressure system
  • “L” indicates a low-pressure system

Latitude lines are labeled at approximately 80°N, 60°N, 40°N, 20°N, the Equator (0°), 20°S, 40°S, 60°S, and 80°S.

Northern Hemisphere Patterns (Winter Season)

In January, the Northern Hemisphere is in winter, and the map shows strong pressure contrasts:

• High-pressure systems (H):
  • A large, intense high-pressure area over central and eastern Asia (Siberian High).
  • Additional high-pressure zones over the North Atlantic and North Pacific Oceans.
• Low-pressure systems (L):
  • Prominent lows near Iceland and the North Atlantic (Icelandic Low).
  • A low-pressure area over the North Pacific near Alaska (Aleutian Low).

These patterns reflect cold, dense air over continents (high pressure) and relatively warmer ocean areas (low pressure).

Tropical Region (Near the Equator)

• Around the Equator, pressures are generally lower (around or below 1,008 mb).
• This corresponds to the Intertropical Convergence Zone (ITCZ), where warm air rises.
• Some localized low-pressure areas appear over northern South America and central Africa.

Southern Hemisphere Patterns (Summer Season)

In January, the Southern Hemisphere is in summer:

• High-pressure systems (H):
  • Broad high-pressure belts over the South Atlantic, South Pacific, and Indian Oceans, roughly between 20°S and 40°S.
• Low-pressure systems (L):
  • Lower pressure over continental regions, including parts of South America, southern Africa, and Australia, due to heating of land surfaces.
• Around Antarctica (near 60°S to 70°S):
  • A band of lower pressure (subpolar low belt) encircles the continent.
  • The interior of Antarctica shows higher pressure due to cold, dense air.

Figure 7.3.3 Global Map of Average Sea-Level Atmospheric Pressure in July

This image is a world map in an oval (Robinson-style) projection titled “Average Sea-Level Atmospheric Pressures in July.” It shows the global distribution of sea-level atmospheric pressure in July.

Chart Structure and Legend

• Continents are shown in light tan; oceans are shaded in varying blues.
• A legend on the right indicates pressure ranges in millibars (mb):
  • Dark blue/teal: Over 1,024 mb (highest pressure)
  • Medium blue: 1,016 to 1,024 mb
  • Light blue-gray: 1,008 to 1,016 mb
  • Light tan: 1,000 to 1,008 mb
  • Darker tan/orange: Under 1,000 mb (lowest pressure)
• Letters mark pressure systems:
  • “H” = High-pressure cell
  • “L” = Low-pressure cell

Latitude lines are labeled at intervals from about 80°N to 80°S, including the Equator.

Northern Hemisphere Patterns (Summer Season)

In July, the Northern Hemisphere is in summer, and pressure patterns shift compared to winter:

• Low-pressure systems (L):
  • A large, dominant low-pressure region over South and Central Asia (often called the Asian Low), extending across parts of the Middle East and India.
  • Additional smaller low-pressure areas appear over northern Africa and parts of North America due to strong land heating.
• High-pressure systems (H):
  • Strong subtropical highs over the North Atlantic (Azores High) and North Pacific (Hawaiian High).
  • These highs are located over oceans, roughly between 20°N and 40°N.

Tropical Region (Near the Equator)

• The Equatorial zone shows relatively low pressure (around or below 1,008 mb).
• This corresponds to the Intertropical Convergence Zone (ITCZ), where warm air rises and surface winds converge.
• The ITCZ appears slightly shifted north of the Equator in July, following the sun’s position.

Southern Hemisphere Patterns (Winter Season)

In July, the Southern Hemisphere is in winter:

• High-pressure systems (H):
  • Strong high-pressure areas over continental interiors, including Australia, southern Africa, and parts of South America, due to cooler land temperatures.
  • Persistent high-pressure belts over the southern oceans between about 20°S and 40°S.
• Low-pressure systems (L):
  • A continuous band of lower pressure around 60°S, known as the subpolar low-pressure belt, encircling Antarctica.
• Antarctica:
  • The interior shows very high pressure, associated with extremely cold, dense air.

Figure 7.3.4 A map of the world's rainforests

The image is a global map showing the distribution of tropical rainforests. The continents are displayed in light gray, and rainforest regions are highlighted in dark green. Several dashed horizontal lines mark key lines of latitude: 66.3° North, 23.5° North, the Equator, 23.5° South, and 66.3° South. The map emphasizes that tropical rainforests are concentrated near the Equator, within the band between the Tropic of Cancer (23.5° N) and the Tropic of Capricorn (23.5° S).

Latitude Markers

Five dashed horizontal latitude lines are labeled:

• 66.3° N (Arctic Circle)
• 23.5° N (Tropic of Cancer)
• Equator (0°)
• 23.5° S (Tropic of Capricorn)
• 66.3° S (Antarctic Circle)

The rainforest regions appear almost entirely between 23.5° N and 23.5° S.

Major Rainforest Regions Highlighted

1. South America (Amazon Basin)

• The largest continuous dark green area appears in northern South America.
• Covers much of Brazil and extends into Peru, Colombia, Venezuela, Ecuador, Bolivia, and surrounding countries.
• Centered on the Equator.
• This represents the Amazon Rainforest, the largest tropical rainforest in the world.

2. Central America

• A narrow band of green runs through southern Mexico and into Central American countries such as Guatemala, Costa Rica, and Panama.
• Connects northward from the Amazon region.

3. Central and West Africa

• A large dark green region appears around the Equator in central Africa.
• Covers parts of the Democratic Republic of the Congo, Republic of the Congo, Gabon, Cameroon, and neighboring countries.
• Represents the Congo Basin rainforest.

4. Southeast Asia

• Extensive green areas appear in:
  • Southern India and Sri Lanka
  • Mainland Southeast Asia
  • The Malay Peninsula
  • Indonesia
  • The Philippines
  • Papua New Guinea

This region is part of the third-largest global concentration of tropical rainforests.

5. Madagascar

• A smaller green area appears along Madagascar's eastern coast, off the southeast coast of Africa.

Figure 7.3.5 A map of the world's deserts

The image is a global map showing the distribution of the world’s major desert regions. Continents are displayed in light gray with subtle shading. Desert areas are highlighted in bright orange. Dashed horizontal lines mark important latitudes: 66.3° North, 23.5° North (Tropic of Cancer), the Equator, 23.5° South (Tropic of Capricorn), and 66.3° South. The map shows that most deserts occur near 23.5° North and 23.5° South, though some extend into higher latitudes.

Latitude Reference Lines

Five dashed lines appear across the map:

• 66.3° N (Arctic Circle)
• 23.5° N (Tropic of Cancer)
• Equator (0°)
• 23.5° S (Tropic of Capricorn)
• 66.3° S (Antarctic Circle)

Most desert regions cluster near the Tropics rather than near the Equator.

Major Desert Regions Highlighted

North America

• Southwestern United States and northern Mexico (including areas such as the Mojave, Sonoran, and Chihuahuan deserts).
• Located near and just north of 23.5° N.

South America

• A narrow strip along the west coast (the Atacama Desert in Chile and Peru).
• A large desert region in southern Argentina (Patagonian Desert), extending farther south than most tropical deserts.

Africa

• A vast continuous region across North Africa, representing the Sahara Desert, centered around 23.5° N.
• Smaller desert areas in southwestern Africa (the Namib Desert) and southern Africa (the Kalahari region).

Middle East and North Africa

• The Arabian Peninsula extends eastward from the Sahara across Saudi Arabia and surrounding regions.

Central and East Asia

• A large desert region in Mongolia and northern China (Gobi Desert).
• Additional arid regions extend westward into Central Asia.

Australia

• A broad desert region across central Australia, centered near 23.5° S.

Figure 7.3.6 A Map of Global Ocean Currents

The image is a world map in the Robinson projection showing the major global ocean currents. Landmasses are shaded light tan, oceans are light blue-gray, and currents are represented by directional arrows.

• Warm currents are shown in red arrows.
• Cold currents are shown in blue arrows.
• Some neutral or connecting flows appear in black.
• Latitude reference lines are shown at approximately 60°, 30°, 0° (Equator), −30°, and −60°.
• A legend at the bottom indicates red for warm currents and blue for cold currents.

Major Currents by Ocean Basin

Atlantic Ocean

Warm Currents (Red):

• Gulf Stream: Flows northward along the eastern United States, then northeast toward Europe.
• Brazil Current: Flows southward along the east coast of South America.
• North Atlantic Drift: Extension of the Gulf Stream moving toward northwestern Europe.
• Norwegian Current: Continues warm water into the Arctic region.

Cold Currents (Blue):

• Labrador Current: Flows southward from the Arctic along eastern Canada.
• Canary Current: Flows southward along northwest Africa.
• Benguela Current: Flows northward along southwest Africa.

The Atlantic shows a large clockwise circulation (gyre) in the Northern Hemisphere and a counterclockwise circulation in the Southern Hemisphere.

Pacific Ocean

Warm Currents (Red):

• Kuroshio Current: Flows northward along the east coast of Japan.
• East Australia Current: Flows southward along eastern Australia.
• North Pacific Drift: Moves eastward across the northern Pacific.

Cold Currents (Blue):

• California Current: Flows southward along the west coast of North America.
• Peru (Humboldt) Current: Flows northward along the west coast of South America.
• Oyashio Current: Flows southward from the Arctic toward Japan.
• West Australia Current: Flows northward along Western Australia.

The Pacific also shows circular gyres:

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

Indian Ocean

Warm Currents:

• Mozambique Current and related flows moving southward along southeast Africa.
• South Equatorial flows across the basin.

Cold Currents:

• West Australia Current along Western Australia.

The Indian Ocean circulation reverses seasonally in parts due to monsoon winds (not explicitly labeled but implied by current structure).

Equatorial Currents

Across all three major oceans:

• North Equatorial Current flows westward just north of the Equator.
• South Equatorial Current flows westward just south of the Equator.
• Equatorial Countercurrent flows eastward between them.

These currents form part of the tropical circulation system.

Southern Ocean

• The Antarctic Circumpolar Current flows continuously eastward around Antarctica.
• The Antarctic Subpolar Current also circles Antarctica.

These currents connect the Atlantic, Pacific, and Indian Oceans.

Figure 7.3.7 A map of surface high and low pressures.

A simplified diagram showing the typical distribution of atmospheric pressure at the equator and around 30 degrees latitude in both the Northern and Southern Hemispheres. It represents the pressure pattern associated with Earth's tropical atmospheric circulation and the trade winds. Three latitude zones are identified on the right side: 30°N at the top, 0° (Equator) across the middle, and 30°S at the bottom.

• At the equator, a thick horizontal black line extends almost completely across the image. Six large red letters "L," representing low atmospheric pressure, are evenly spaced along this line. The right side of the line is labeled "0° (Equator)."
• Near the top of the diagram, six large blue letters "H," representing high atmospheric pressure, are evenly distributed across the region corresponding to approximately 30°N. A short black line beside the final "H" points to the label "30°N."
• Near the bottom, another row of six blue letters "H" represents high atmospheric pressure around 30°S. A short black line beside the final "H" points to the label "30°S."

Figure 7.4.1 The Walker Circulation during Neutral Conditions

This figure illustrates normal atmospheric and oceanic circulation patterns across the tropical Pacific Ocean under non-El Niño conditions.

Layout:

• This is a 3D cross-section of the equatorial Pacific Ocean, oriented with:
  • Australia and Southeast Asia (west) on the left side (labeled ~120°E longitude)
  • South America (east) on the right side (labeled ~80°W longitude)
  • The Equator runs horizontally across the center.
• Ocean and Atmosphere Features:
  • Warm ocean surface waters are piled up in the western Pacific due to easterly trade winds.
  • Cooler ocean water dominates the eastern Pacific, near the coast of South America.
  • A sloping thermocline—the boundary between warm surface water and cold deep water—is shown dipping deeper in the west and rising toward the surface in the east.
  • Upwelling is occurring along the South American coast, where cold water is rising to the surface.
  • White arrows near the ocean surface indicate the direction of surface winds (easterlies)—from east to west.
  • Convective clouds and rising air are located over the warm waters of the western Pacific, indicating strong convection and thunderstorm activity.
  • Dashed arrows indicate the atmospheric return flow aloft, moving from west to east and completing the Walker convective circulation loop.

Annotations:

• Labeled “Neutral Conditions” at the top, this configuration shows typical Walker Cell circulation:
  • Surface winds blow from east to west (trade winds).
  • Warm water and rising air in the western Pacific support deep convection and rainfall.
  • Cooler water and sinking air in the eastern Pacific result in dry conditions.

Figure 7.4.2 Positions of TAO/Triton Array Buoys

This map displays the Global Tropical Moored Buoy Array, which consists of oceanographic buoys distributed across the tropical Pacific, Indian, and Atlantic Oceans as of July 2025. These buoys cover vast regions across the respective oceans and are part of three regional networks used for long-term climate and ocean monitoring.

• RAMA-2.0 (Indian Ocean, left side of map)
• TAO (Pacific Ocean, center of map)
• PIRATA (Atlantic Ocean, right side of map)

Map Layout:

• The map spans latitudes from 30°N to 30°S and longitudes from 60°E to 0°E, wrapping around the globe from the Indian Ocean to the Atlantic.
• Landmasses include Africa, South America, Southeast Asia, and Australia.
• Buoy positions are marked across the ocean basins with various colored squares, each color representing a different type of mooring instrumentation.

Buoy Types and Symbols:

Each square represents a buoy site.

• Solid squares = currently operating
• Open squares = planned deployment
• Colored coding represents standard mooring (red), flux reference sites (blue), flux and CO₂ enhanced (purple), and CO₂ enhanced (green) buoy locations.

Figure 7.4.3 Sea Surface Temperatures for July 2018

This figure contains two horizontal panels representing TAO/TRITON ocean monitoring data for the equatorial Pacific Ocean, covering the five-day period ending July 2, 2018. The panels display sea surface temperature (SST) and surface wind vectors, with the lower panel also showing anomalies relative to climatological averages.

Top Panel – “Means” (Sea Surface Temperature and Wind):

• The top panel shows SST in degrees Celsius (°C) across a horizontal section of the equatorial Pacific, from 140°E to 100°W longitude, and 10°S to 10°N latitude.
• A gradient ranges from:
  • 30°C in the western Pacific near 140°E,
  • 20–26°C as it moves eastward toward South America.
  • Contour lines labeled (e.g., 30, 29, 28…) indicate lines of equal SST (isotherms).
  • Wind vectors (arrows) represent average surface winds, generally showing easterly trade winds blowing from east to west across the central Pacific.

Bottom Panel – “Anomalies” (SST and Wind Deviations from Normal):

• This panel shows SST anomalies (differences from long-term averages) for the same region and time period.
• The color gradient ranges from:
  • +2 to +4°C for positive anomalies (warmer than normal),
  • -2 to -4°C for negative anomalies (cooler than normal).
• Overall, the anomalies are mostly near zero, indicating neutral ENSO conditions (neither El Niño nor La Niña).
• Contour lines labeled with numbers (e.g., 0, +1, -1) delineate SST anomaly values.
• Wind anomaly vectors (arrows) show small deviations in direction and magnitude, indicating slight variations from typical trade wind patterns.

Figure 7.4.4 The Walker Circulation during El Niño

This is a 3D schematic cross-section of the equatorial Pacific Ocean, illustrating El Niño conditions within the El Niño–Southern Oscillation (ENSO) cycle.

Layout:

• The diagram spans from 120°E (left) to 80°W (right) along the equator, depicting ocean and atmospheric patterns across the tropical Pacific.
• The left side represents the western Pacific (near Indonesia and Australia).
• The right side represents the eastern Pacific (near South America).

Key Features:

Ocean Structure:

• Warm surface water stretches uniformly across the Pacific, from west to east.
• Cooler water is confined to deeper layers and pushed downward throughout the entire basin.
• The thermocline, the boundary between warm surface water and cooler deep water, is shown as flat and deep, unlike in normal conditions when it is tilted.
• Upwelling of cold water is suppressed near South America.

Surface Winds:

• The usual trade winds (from east to west) are weakened or reversed.
• Black arrows along the ocean surface indicate weakened or reversed wind direction, blowing from west to east across the equator.

Atmosphere:

• Rising air and deep convection (clouds and upward arrows) are now centered in the central and eastern Pacific, rather than over the western Pacific.
• Dashed white arrows show upper-level atmospheric return flow, completing a disrupted Walker circulation loop.
• Rainfall and thunderstorm activity are displaced eastward, toward the central Pacific.

Figure 7.4.5 The Walker Circulation during La Niña.

This is a 3D schematic cross-section of the equatorial Pacific Ocean, illustrating La Niña conditions, a component of the El Niño–Southern Oscillation (ENSO) climate pattern.

Layout:

• The cross-section extends from 120°E (left) to 80°W (right) along the equator.
• Western Pacific (left side) represents the region near Australia and Southeast Asia.
• Eastern Pacific (right side) represents the region near South America.

Ocean Features:

• Warm surface waters are pushed farther west than normal, accumulating in the western Pacific.
• The eastern Pacific is dominated by cooler waters.
• The thermocline, the boundary between warm and cold water, is steeper than normal, being much shallower near South America and deeper in the western Pacific.
• Strong upwelling of cold, nutrient-rich water is shown off the coast of South America.

Atmospheric Circulation:

• Surface trade winds (arrows along the surface) are stronger than normal, blowing east to west across the Pacific.
• These winds drive warm surface water westward and enhance upwelling in the east.
• Rising air and deep convection (indicated by black upward arrows and clouds) are concentrated over the western Pacific, where the water is warmest.
• A dashed white arrow above the surface indicates upper-level atmospheric return flow moving west to east, completing the Walker circulation.
• Sinking air and dry conditions are shown over the eastern Pacific, near South America.

Figure 7.4.6 Sea Surface Temperatures and Anomalies for December 2015

This figure shows sea surface temperature (SST) and wind data across the equatorial Pacific Ocean during December 2015, based on measurements from the TAO/TRITON buoy array. The data is presented in two horizontal panels:

Top Panel – “Means” (Sea Surface Temperature and Wind):

• This panel shows average SSTs (in °C) and surface winds between 10°N and 10°S latitude, from 140°E to 100°W longitude.
• The SSTs are displayed using a color gradient from:
  • 30°C in the western and central Pacific,
  • 26–28°C in the east,
  • 18–22°C near South America.
  • Isotherms (contour lines) mark temperatures at 1°C intervals (e.g., 30°C, 29°C, 28°C).
  • Wind vectors (arrows) show the direction and magnitude of surface winds:
• Arrows mostly point from west to east across the central and eastern Pacific,
• Indicating weakened or reversed trade winds, which are typical of El Niño events.

Bottom Panel – “Anomalies” (SST and Wind):

• This panel shows deviations from the average (climatological) conditions.
• Color shading indicates SST anomalies (in °C), with:
  • Positive anomalies (+2 to +3.5°C) in the central and eastern equatorial Pacific.
  • The strongest warming occurs between 160°W and 100°W, peaking at about +3.5°C.
  • Areas with cooler-than-normal SSTs (very limited in this case).
• Contour lines trace SST anomaly values (e.g., 1.5, 2.0, 3.0).
• Wind anomaly vectors point eastward, indicating weakened or reversed easterly winds, consistent with El Niño.

Figure 7.4.7 Sea Surface Observations and Anomalies for December 2010

This figure presents monthly sea surface temperature (SST) and wind data from the TAO/TRITON buoy array for the equatorial Pacific Ocean during December 2010. It includes two horizontal panels:

Top Panel – “Means” (Sea Surface Temperature and Wind):

• The panel displays average SSTs and wind vectors between 10°N and 10°S latitude, from 140°E to 100°W longitude.
• A gradient represents SSTs from:
  • 30°C in the western Pacific,
  • 18–24°C as it moves eastward toward South America.
  • Contour lines (isotherms) labeled at 1°C intervals (e.g., 29, 28, 26°C) trace regions of equal temperature.
  • Arrows show surface wind direction and speed:
• Arrows point strongly from east to west, indicating intensified easterly trade winds typical of La Niña.

Bottom Panel – “Anomalies” (SST and Wind):

• This panel shows anomalies (differences from the long-term average).
• SST anomalies from -1°C to -3°C dominate the central and eastern Pacific, showing cooler-than-average water.
• Contour lines labeled -1.5, -2.0, etc., trace the extent of cold anomalies.
• Wind anomaly vectors show stronger-than-normal easterlies, reinforcing the cooling effect.