<<–2/”>a href=”https://exam.pscnotes.com/5653-2/”>h2>SST: Sea Surface Temperature
What is SST?
Sea surface temperature (SST) refers to the temperature of the ocean’s surface layer, typically measured at a depth of a few meters. It is a crucial parameter in understanding and monitoring various aspects of the Earth’s Climate system, including:
- Ocean circulation: SST influences the density of ocean water, driving currents and influencing global heat distribution.
- Weather and climate: SST plays a significant role in atmospheric circulation patterns, influencing weather events like hurricanes and El Niño-Southern Oscillation (ENSO).
- Marine Ecosystems: SST directly impacts the distribution and abundance of marine species, influencing Fisheries-2/”>Fisheries and Biodiversity-2/”>Biodiversity.
- Climate Change: SST is a key indicator of Global Warming, showing long-term trends and variability.
Measuring SST
SST is measured using various methods, each with its own advantages and limitations:
1. In-situ measurements:
- Buoys: Moored or drifting buoys equipped with sensors measure SST directly at the surface.
- Ships: Ships equipped with sensors collect SST data along their routes.
- Argo floats: Autonomous underwater robots that collect data at various depths, including SST, and transmit it to satellites.
2. Remote sensing:
- Satellites: Satellites equipped with infrared sensors measure the thermal radiation emitted by the ocean surface, which is directly related to SST.
Table 1: Comparison of SST Measurement Methods
| Method | Advantages | Disadvantages |
|---|---|---|
| In-situ buoys | High accuracy, continuous data | Limited spatial coverage, expensive |
| In-situ ships | High accuracy, wide spatial coverage | Discontinuous data, influenced by ship emissions |
| In-situ Argo floats | Global coverage, continuous data | Limited depth range, susceptible to drift |
| Satellite remote sensing | Global coverage, frequent data | Lower accuracy, affected by cloud cover |
Importance of SST
SST plays a vital role in various aspects of the Earth’s system:
1. Ocean Circulation:
- Thermohaline circulation: SST influences the density of ocean water, driving the global conveyor belt, a system of deep ocean currents that transports heat and nutrients around the globe.
- Surface currents: SST gradients create differences in water density, driving surface currents like the Gulf Stream, which transports warm water from the tropics towards higher latitudes.
2. Weather and Climate:
- Hurricanes: Warm SST provides the energy for hurricane formation and intensification.
- El Niño-Southern Oscillation (ENSO): SST anomalies in the central and eastern Pacific Ocean influence global weather patterns, leading to changes in rainfall, temperature, and wind patterns.
- Monsoons: SST gradients between land and ocean influence the formation and intensity of monsoons, bringing seasonal rainfall to many regions.
3. Marine Ecosystems:
- Species distribution: SST influences the distribution of marine species, as different species have different temperature tolerances.
- Primary productivity: SST affects the rate of Photosynthesis in phytoplankton, the base of the marine food web.
- Fisheries: SST fluctuations can impact the abundance and distribution of commercially important fish species.
4. Climate Change:
- Global warming: SST has been steadily increasing over the past century, a clear indicator of global warming.
- Sea level rise: Warming Oceans expand in volume, contributing to sea level rise.
- Ocean Acidification: As oceans absorb more carbon dioxide from the Atmosphere, they become more acidic, impacting marine ecosystems.
Table 2: Impacts of SST on Different Aspects of the Earth’s System
| Aspect | Impact of SST |
|---|---|
| Ocean circulation | Drives thermohaline circulation and surface currents |
| Weather and climate | Influences hurricane formation, ENSO, and monsoons |
| Marine ecosystems | Affects species distribution, primary productivity, and fisheries |
| Climate change | Indicator of global warming, contributes to sea level rise and ocean acidification |
SST Anomalies
SST anomalies refer to the difference between the observed SST and the long-term Average SST for a given location and time period. These anomalies can be positive (warmer than average) or negative (cooler than average).
Causes of SST Anomalies:
- Natural variability: Ocean currents, wind patterns, and atmospheric circulation can cause natural fluctuations in SST.
- Climate change: Long-term warming trends are causing a gradual increase in global SST.
- Volcanic eruptions: Volcanic eruptions can release aerosols into the atmosphere, reflecting sunlight and cooling the ocean surface.
Impacts of SST Anomalies:
- Extreme weather events: SST anomalies can influence the frequency and intensity of extreme weather events, such as heat waves, droughts, and floods.
- Marine ecosystem shifts: SST anomalies can cause shifts in the distribution and abundance of marine species, impacting fisheries and biodiversity.
- Climate feedback loops: SST anomalies can influence atmospheric circulation patterns, creating feedback loops that can amplify or dampen climate change.
SST and Climate Change
SST is a key indicator of global warming and plays a crucial role in climate change:
- Rising SST: Global SST has been steadily increasing over the past century, a direct result of human-induced climate change.
- Ocean heat content: The ocean absorbs a significant amount of heat from the atmosphere, leading to an increase in ocean heat content.
- Sea level rise: Warming oceans expand in volume, contributing to sea level rise.
- Ocean acidification: As oceans absorb more carbon dioxide from the atmosphere, they become more acidic, impacting marine ecosystems.
Frequently Asked Questions (FAQs)
1. What is the average SST of the ocean?
The average SST of the global ocean is about 17°C (63°F). However, SST varies significantly depending on location, season, and other factors.
2. How does SST affect weather patterns?
SST influences atmospheric circulation patterns, driving weather events like hurricanes, El Niño-Southern Oscillation (ENSO), and monsoons.
3. How is SST measured?
SST is measured using various methods, including in-situ buoys, ships, Argo floats, and satellite remote sensing.
4. What are SST anomalies?
SST anomalies refer to the difference between the observed SST and the long-term average SST for a given location and time period.
5. How does SST relate to climate change?
SST is a key indicator of global warming and plays a crucial role in climate change, contributing to sea level rise and ocean acidification.
6. What are the impacts of SST anomalies?
SST anomalies can influence extreme weather events, marine ecosystem shifts, and climate feedback loops.
7. How can we monitor SST?
SST is continuously monitored by various organizations, including the National Oceanic and Atmospheric Administration (NOAA) and the European Centre for Medium-Range Weather Forecasts (ECMWF).
8. What are the future projections for SST?
Climate models predict that SST will continue to rise in the future, with significant impacts on weather, climate, and marine ecosystems.
9. What can we do to mitigate the impacts of rising SST?
Reducing greenhouse gas emissions is crucial to mitigating the impacts of rising SST and climate change.
10. How can I learn more about SST?
You can find more information about SST on websites like NOAA, NASA, and the Intergovernmental Panel on Climate Change (IPCC).