The ocean is not a still body of water. There is constant motion
in the ocean in the form of a global ocean conveyor belt due to
thermohaline currents. These currents are density driven, which are
affected by both temperature and salinity. Cold, salty water is
dense and sinks to the bottom of the ocean while warm water is less
dense and rises to the surface. The "start" of the ocean conveyor
belt is in the Norwegian Sea. Warm water is transported to the
Norwegian Sea by the Gulf Stream. The warm water provides heat for
the atmosphere in the northern latitudes that gets particularly cold
during the winter. This loss of heat to the atmosphere makes the
water cooler and denser, causing it to sink to the bottom of the
ocean. As more warm water is transported north, the cooler water
sinks and moves south to make room for the incoming warm water.
This cold bottom water flows south of the equator all the way down
to Antarctica. Eventually, the cold bottom waters are able to warm
and rise to the surface, continuing the conveyor belt that encircles
the globe. It takes water almost 1000 years to move through the
whole conveyor belt.
There are two datasets that illustrate the ocean circulation. This dataset is an animation that shows the movement of the ocean conveyor belt and the second dataset is a still image that has the major ocean currents labeled. Surface waters are the red lines and
cold, bottom waters are the blue lines. Changes in ocean circulation could have drastic impacts on the climate. The
transport of heat associated with the ocean conveyor belt partially
moderates the cold temperatures in the North. As the poles warm due
to climate change, melt water from ice and glaciers enters the
ocean. This fresh melt water has the potential to slow or even shut
off the ocean circulation, which is dependent on temperature and
salinity. The density of the fresh melt water is less than that of
salty ocean water. This causes the fresh melt water to form a layer
on the surface that can block the warm, salty ocean water from
transporting heat to the atmosphere. The effect would be a cooling
of the higher latitudes. If the warm water is not able to give off
heat, it can not cool and sink to the bottom of the ocean. This
would disturb the circulation of the entire ocean conveyor belt and
have a noticeable impact on the climate in the northern latitudes.
C1 Patterns. Children recognize that patterns in the natural and human designed world can be observed, used to describe phenomena, and used as evidence
C3 Scale Proportion and Quantity. Students use relative scales (e.g., bigger and smaller; hotter and colder; faster and slower) to describe objects. They use standard units to measure length.
C1 Patterns. Students identify similarities and differences in order to sort and classify natural objects and designed products. They identify patterns related to time, including simple rates of change and cycles, and to use these patterns to make predictions.
C3 Scale Proportion and Quantity. Students recognize natural objects and observable phenomena exist from the very small to the immensely large. They use standard units to measure and describe physical quantities such as weight, time, temperature, and volume.
C4 Systems and System Models. Students understand that a system is a group of related parts that make up a whole and can carry out functions its individual parts cannot. They can also describe a system in terms of its components and their interactions.
C1 Patterns. Students recognize that macroscopic patterns are related to the nature of microscopic and atomic-level structure. They identify patterns in rates of change and other numerical relationships that provide information about natural and human designed systems. They use patterns to identify cause and effect relationships, and use graphs and charts to identify patterns in data.
C3 Scale Proportion and Quantity. Students observe time, space, and energy phenomena at various scales using models to study systems that are too large or too small. They understand phenomena observed at one scale may not be observable at another scale, and the function of natural and designed systems may change with scale. They use proportional relationships (e.g., speed as the ratio of distance traveled to time taken) to gather information about the magnitude of properties and processes. They represent scientific relationships through the use of algebraic expressions and equations
C1 Patterns. Students observe patterns in systems at different scales and cite patterns as empirical evidence for causality in supporting their explanations of phenomena. They recognize classifications or explanations used at one scale may not be useful or need revision using a different scale; thus requiring improved investigations and experiments. They use mathematical representations to identify certain patterns and analyze patterns of performance in order to re-engineer and improve a designed system.
C4 Systems and System Models. Students can investigate or analyze a system by defining its boundaries and initial conditions, as well as its inputs and outputs. They can use models (e.g., physical, mathematical, computer models) to simulate the flow of energy, matter, and interactions within and between systems at different scales. They can also use models and simulations to predict the behavior of a system, and recognize that these predictions have limited precision and reliability due to the assumptions and approximations inherent in the models. They can also design systems to do specific tasks.
ESS2.A Earth Materials and Systems. Wind and water change the shape of the land
ESS2.C The Roles of Water in Earth's Processes. Water is found in many types of places and in different forms on Earth
ESS2.C The Roles of Water in Earth's Processes. Most of Earth’s water is in the ocean and much of the Earth’s fresh water is in glaciers or underground.
ESS3.C Human Impact on Earth systems. Societal activities have had major effects on the land, ocean, atmosphere, and even outer space. Societal activities can also help protect Earth’s resources and environments.
ESS3.D Global Climate Change. If Earth’s global mean temperature continues to rise, the lives of humans and other organisms will be affected in many different ways.
ESS2.C The Roles of Water in Earth's Processes. Water cycles among land, ocean, and atmosphere, and is propelled by sunlight and gravity. Density variations of sea water drive interconnected ocean currents. Water movement causes weathering and erosion, changing landscape features.
ESS2.D Weather & Climate. Complex interactions determine local weather patterns and influence climate, including the role of the ocean.
ESS3.C Human Impact on Earth systems. Human activities have altered the biosphere, sometimes damaging it, although changes to environments can have different impacts for different living things. Activities and technologies can be engineered to reduce people’s impacts on Earth.
PS3.A Definitions of Energy. Kinetic energy can be distinguished from the various forms of potential energy. Energy changes to and from each type can be tracked through physical or chemical interactions. The relationship between the temperature and the total energy of a system depends on the types, states, and amounts of matter.
ESS2.C The Roles of Water in Earth's Processes. The planet’s dynamics are greatly influenced by water’s unique chemical and physical properties.
ESS2.D Weather & Climate. The role of radiation from the sun and its interactions with the atmosphere, ocean, and land are the foundation for the global climate system. Global climate models are used to predict future changes, including changes influenced by human behavior and natural factors
ESS3.C Human Impact on Earth systems. Sustainability of human societies and the biodiversity that supports them requires responsible management of natural resources, including the development of technologies that produce less pollution and waste and that preclude ecosystem degradation.
PS1.B Chemical Reactions. Chemical processes are understood in terms of collisions of molecules, rearrangement of atoms, and changes in energy as determined by properties of elements involved.
PS2.C Stability & Instability in Physical Systems. Systems often change in predictable ways; understanding the forces that drive the transformations and cycles within a system, as well as the forces imposed on the system from the outside, helps predict its behavior under a variety of conditions. When a system has a great number of component pieces, one may not be able to predict much about its precise future. For such systems (e.g., with very many colliding molecules), one can often predict average but not detailed properties and behaviors (e.g., average temperature, motion, and rates of chemical change but not the trajectories or other changes of particular molecules). Systems may evolve in unpredictable ways when the outcome depends sensitively on the starting condition and the starting condition cannot be specified precisely enough to distinguish between different possible outcomes.
PS3.A Definitions of Energy. The total energy within a system is conserved. Energy transfer within and between systems can be described and predicted in terms of energy associated with the motion or configuration of particles (objects).