2. Temperature and Salinity of the Oceans

Case Study 1: Rising Ocean Temperatures and Marine Ecosystem Disruptions – Great Barrier Reef

Geographical Thought & Perspectives:

• Thermal Stratification Theory (Ekman, 1905) – Layering of ocean temperatures due to density differences.
• Anthropogenic Climate Change (IPCC, 1988–Present) – Human-induced warming affecting ocean temperatures.
• Marine Heatwave Theory (Hobday et al., 2016) – Extreme ocean temperature anomalies impacting ecosystems.

Models/Theories/Laws:

• Ocean Temperature Gradient Model – Vertical temperature distribution in ocean layers.
• Heat Budget Model – Balance of incoming and outgoing heat in ocean systems.
• ENSO Influence on Ocean Temperature – Oceanic temperature anomalies affecting marine ecosystems.

Recent Data:

• Great Barrier Reef: Recorded sea surface temperature anomalies of +1.5°C.
• Coral Bleaching Impact: Increased bleaching events affecting reef biodiversity.
• Satellite Observations: NOAA confirms warming trends in the Pacific Ocean.

Spatial Variation:

• Northern Reef: Higher temperature anomalies leading to severe bleaching.
• Southern Reef: Less impact due to cooler ocean currents.

Temporal Variation:

• Historical Trends: Ocean warming observed since 2000.
• Future Projections: Expected intensification due to climate change.

Source:

• NOAA Coral Reef Watch
• Nature Climate Change

Insight:

Rising ocean temperatures validate climate models, emphasizing the role of anthropogenic influences in marine ecosystem disruptions.

Case Study 2: Salinity Variability and Ocean Circulation – North Atlantic

Geographical Thought & Perspectives:

• Thermohaline Circulation Theory (Stommel, 1960) – Density-driven ocean currents.
• Climate Variability and Salinity (Lorenz, 1963) – Chaos theory in ocean salinity patterns.
• Anthropogenic Climate Change (IPCC, 1988–Present) – Human-induced disruptions in salinity trends.

Models/Theories/Laws:

• Salinity Gradient Model – Horizontal and vertical salinity distribution.
• Ocean Circulation Model – Influence of salinity on global ocean currents.
• Hydrological Cycle Disruptions – Changes in precipitation affecting salinity.

Recent Data:

• North Atlantic: Increased freshwater influx reducing salinity levels.
• Ocean Circulation Impact: Slowing of the Atlantic Meridional Overturning Circulation (AMOC).
• Satellite Observations: ESA confirms salinity anomalies affecting ocean currents.

Spatial Variation:

• Arctic Region: Increased freshwater input due to ice melt.
• Tropical Atlantic: Higher salinity due to evaporation dominance.

Temporal Variation:

• Historical Trends: Salinity variability observed since 2000.
• Future Projections: Expected further disruptions due to climate change.

Source:

• Copernicus Marine Service
• Nature Climate Change

Insight:

Salinity variability validates ocean circulation models, emphasizing the role of climate change in altering global ocean currents.