Key Idea 1: The Earth and celestial phenomena can be described by principles of relative motion and perspective.

PERFORMANCE INDICATOR 1.1: Explain complex phenomena, such as tides, variations in day length, solar insolation, apparent motion of the planets, and annual traverse of the constellations.

MAJOR UNDERSTANDING 1.1e: The Foucault pendulum and the Coriolis effect provide evidence of Earth's rotation.

Key Idea 2: Many of the phenomena that we observe on Earth involve interactions among components of air, water, and land.

PERFORMANCE INDICATOR 2.1: Use the concepts of density and heat energy to explain observations of weather patterns, seasonal changes, and the movements of Earth's plates.

MAJOR UNDERSTANDING 2.1b: The transfer of heat energy within the atmosphere, the hydrosphere, and Earth's interior results in the formation of regions of different densities. These density differences result in motion.

MAJOR UNDERSTANDING 2.1c: Weather patterns become evident when weather variables are observed, measured, and recorded. These variables include air temperature, air pressure, moisture (relative humidity and dewpoint), precipitation (rain, snow, hail, sleet, etc.), wind speed and direction, and cloud cover.

• Temperature and humidity affect air pressure and probability of precipitation

• Air pressure gradient controls wind velocity

MAJOR UNDERSTANDING 2.1g: Weather variables can be represented in a variety of formats including radar and satellite images, weather maps (including station models, isobars, and fronts), atmospheric cross-sections, and computer models.

MAJOR UNDERSTANDING 2.1h: Atmospheric moisture, temperature and pressure distributions; jet streams, wind; air masses and frontal boundaries; and the movement of cyclonic systems and associated tornadoes, thunderstorms, and hurricanes occur in observable patterns. Loss of property, personal injury, and loss of life can be reduced by effective emergency preparedness.

PERFORMANCE INDICATOR 2.2: Explain how incoming solar radiation, ocean currents, and land masses affect weather and climate.

MAJOR UNDERSTANDING 2.2a: Insolation (solar radiation) heats Earth’s surface and atmosphere unequally due to variations in:

• The intensity caused by differences in atmospheric transparency and angle of incidence which vary with time of day, latitude, and season

MAJOR UNDERSTANDING 2.2b: The transfer of heat energy within the atmosphere, the hydrosphere, and Earth’s surface occurs as the result of radiation, convection, and conduction.

• Heating of Earth's surface and atmosphere by the Sun drives convection within the atmosphere and oceans, producing winds and ocean currents.

KEY IDEA 1: The central purpose of scientific inquiry is to develop explanations of natural phenomena in a continuing and creative process

PERFORMANCE INDICATOR 1.2: Hone ideas through reasoning, library research, and discussion with others, including experts

PERFORMANCE INDICATOR 1.3: Work towards reconciling competing explanations; clarify points of agreement and disagreement

PERFORMANCE INDICATOR 1.4: Coordinate explanations at different levels of scale, points of focus, and degrees of complexity and specificity, and recognize the need for such alternative representations of the natural world.

KEY IDEA 2: Beyond the use of reasoning and consensus, scientific inquiry involves the testing of proposed explanations involving the use of conventional techniques and procedures and usually requiring considerable ingenuity

PERFORMANCE INDICATOR 3.3: Assess correspondence between the predicted result contained in the hypothesis and actual result, and reach a conclusion as to whether the explanation on which the prediction was based is supported

Key to Weather Map Symbols (p.13)

Reading: Craft and Structure

Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 9–10 texts and topics.

Reading: Integration of Knowledge and Ideas

Translate quantitative or technical information expressed in words in a text into visual form (e.g., a table or chart) and translate information expressed visually or mathematically (e.g., in an equation) into words.

Reading: Range of Reading and Level of Text Complexity

By the end of grade 10, read and comprehend science/technical texts in the grades 9–10 text complexity band independently and proficiently

Writing: Range of Writing

Write routinely over extended time frames (time for reflection and revision) and shorter time frames (a single sitting or a day or two) for a range of discipline-specific tasks, purposes, and audiences.