B. Atmosphere, ocean and climate

B. Atmosphere, ocean and climate

B.1 Hurricanes and typhoons

Nature of science:

  • Models, based on theoretical understanding, are developed to explain processes that are not observable.

  • Theories and laws can be used to describe phenomena and make predictions about future occurrences.

Understandings:

  • Hurricane or typhoon is an intense tropical storm that originates over warm ocean waters with wind speed of at least 119 km per hour (74 mph),

  • Hazards from hurricanes include storm surges, flooding rains, strong winds and tornados

  • Conditions for generating a tropical cyclone include high sea -surface temperatures, adequate Coriolis effect and weak winds aloft.

  • Energy source for hurricanes is latent heat released when water vapour evaporated from the ocean condenses.

  • Depending upon wind speed, tropical storms are labeled as disturbance, depression, storm and hurricane

Applications and skills:

  • Application: SLOSH and topographic analysis from models help in the prediction of flooding

  • Skill: On a map track an approaching hurricane from coordinate data and time using available interval

  • Skill: using models estimating likely storm intensity

B.2 Climate, the oceans and the cryosphere

Nature of science:

  • Scientists use observed and measured patterns to form explanations and make predictions.

Understandings:

  • Factors that affect climate include latitude, proximity to large bodies of water (ocean), net incoming solar radiation, long-term average atmospheric circulation and prevailing ocean circulation.

  • Climate responds daily, seasonally, decadally and on to time-scales that are millions of years; oceanic influences are similar in periodicity.

  • El Niño, La Niña and the southern oscillation involve a sequence of events that are a response to changes along the equatorial Pacific

  • Teleconnections is a relatively new term in atmospheric science and is defined by the American Meteorological Society as "A linkage between weather changes occurring in widely separated regions of the globe"

  • Teleconnections result in El Niño and La Niña events having ripple effects on weather and climate in the mid-latitudes.

  • The ocean conveyor belt distributes heat affecting climate

  • Ice on Antarctica, sea ice in the Southern ocean and the Arctic ocean have major impact on Earth's climate

Applications and skills:

  • Skill: Tracking SST of the Pacific Ocean to predict whether or not an El Niño, La Niña, or average year is developing.

  • Skill: data-mining: seasonal changes in SST of either the Pacific or the Atlantic. From the data hypothesizing about the causes or impacts of these changes. Archived data may be used.

  • Skill: data-mining the extent of sea ice at either of the poles over a period of time. Posing questions that can be answered by analysis of the data.

B.3 Climate record and climate change

Nature of science:

  • Since climatic events cannot be tested, how can they be considered scientific?

Understandings:

  • Scientists use climatic evidence in rock, fossils, pollen, tree growth rings, deep-sea sediment cores and ice cores.

  • Characteristics of climate change are difficult to make as it is variable geographically and from time to time; it can involve changes in averages or changes in extremes

  • Generally climate change is more abrupt than gradual

  • Forcing mechanisms are unreliable predictors.

  • Causes of climate change may include solar output variability (sunspots), Milankovitch cycles, volcanic eruptions, relative distribution of ocean and land, human activity

  • Increase in atmospheric carbon dioxide is driving carbon dioxide across the air/sea interface

Applications and skills:

  • Skill: constructing a timeline of prehistoric climates

  • Application: predicting consequences for climate if the ocean conveyor belt stops as it has in the past. Designing an experiment to examining whether or not this is likely to happen.

  • Skill: examining the recent findings of the IPCC; critically evaluating the science behind the knowledge claim.

  • skill: Calculating the your personal carbon footprint.

  • Application: discussing the precautionary principle with regard to human enhanced greenhouse gases and global warming.

B.4 Climate modeling

Nature of science:

  • Models, some simple, some very complex, based on theoretical understanding, are developed to explain processes that may not be observable. Computer-based mathematical models are used to make testable predictions, which can be especially useful when experimentation is not possible.

Understandings:

  • Climate models consist of equations used to predict positive and negative temperature and precipitation anomalies

  • Numerical models are used to predict El Niño/La Niña events (the empirical model uses past occurrences, whereas the dynamical model uses equations that simulate ocean/atmosphere coupling.

Applications and skills:

  • Application: examining the inputs for two or more models and discussing why climate models are so variable in their conclusions

  • Skill: Modeling climate changes using a computer simulation.

  • Application: discussion of the impact of increased atmospheric carbon dioxide on oceans, greenhouse effect, ocean acidification and climate.

B.5 Science to mitigate coastal disasters

Nature of science:

  • Scientists work to assist with disaster preparedness by creating models to solve problems and improve man's lot.

Understandings:

  • Storm surges are large waves that bring coastal destruction and flooding

  • Rising sea level due to global warming causes local flooding as well as salt intrusion

  • Disasters are measured, risks analysed, interventions are made

  • Steps used in some communities to limit damage may form a basis for modeling mitigation designs

  • Structures such as dikes, sea walls, special building construction have limits to their effectiveness.

Applications and skills:

  • Skill: developing testable models to alleviate components of coastal disasters.

  • Application: Choose a place with damage from a storm surge or hurricane and describe what was done to prepare for the disaster, what relief was provided, and what plans have been made for the future.

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