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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