Chapter 1 : introduction to the atmosphere

What is a Hypothesis?

A hypothesis is a tentative (untested) explanation that is made using factual evidence and logical thought.

What is a theory?

A theory is a hypothesis that has passed many texts and explains a series of observations successfully.

what is a law?

A Law is scientific principle (usually in the form of mathematical equations) that can accurately predict the outcomes of some experiment. Laws do not explain why something happen but just what WILL happen.

What are the nature of scientific inquiry in a hypothesis?

• science question

• hypothesis

• theory

what are the nature of scientific inquiry in a theory?

• science question

• hypothesis

• law: law of conservation of mass

What is scientific method?

It raised question about the natural world. Collect related data and observations. Pose a question experiments and create model to help explain observe phenomena and test the hypotheses. Interpret data and make conclusions. Accept, modify or reject hypotheses. Share data and results with other scientists for critical examination and further testing.

what is the Karman line and why is it significant?

it is unofficial top of the atmosphere at 100 km (62 miles) only 1.57% of Earth’s total radius.

• Named after Theodore von Karman

What is remarkable about where life exists in the Biosphere?

Life is mostly near the surface but has been found miles deep in the ocean under extreme pressure in boiling hot springs, miles deep in rocks and floating in the atmosphere.

• Extremophiles exist everywhere.

What is a temperature inversion?

an atmospheric layer where temperature increases with altitude (the reverse of normal). They can cap convection, and if that cap breaks, violent thunderstorms can erupt suddenly.

• Common in summer evenings or under a warm air mass.

How does the height of the tropopause vary?

it is highest in the tropics ( up to ~17 km) and lowest at the poles (~9 km). Colder, denser air lowers its height; it also varies with seasons.

• warm air = taller troposphere

why does the stratosphere get warmer with altitude?

because it contains the ozone layer, which absorbs UV radiation and re-released it as heat, causing temperature to increase upward.

• ozone = UV absorber

What cause auroras and in which layer do they occur?

auroras occur in the thermosphere when charged solar particles interact with Earth’s magnetic field.

• also called Northern/southern lights

How was Earth’s early atmosphere formed?

by ‘outgassing’ from the mantle during differentiation and subsequent volcanism.

• differentiation = settling of earth’s layers

What climate type does NYC have and what are its key traits?

humid subtropical to humid continental climate like long hot summers, cool winters, four distinct seasons, and consistent precipitation with no predictable dry season.

• like Tennessee, Texas and Florida share this classification.

what is atmospheric pressure and what is the value at sea level?

the force per unit area the atmosphere exerts perpendicular to the surface about 14.7 pounds per square inch or ~1013 millibars at sea level.

• formula: P = mg/ A or P=pgh

What does the Keeling curve show?

the continuous record of CO2 concentrations measured at Mauna Loa Observatory it documents the steady rise of atmospheric CO2 since systematic measurements began in 1958.

• Named for Charles David Keeling

What is a hypothesis?

A tentative, untested explanation made from factual evidence and logical thought.

What are current and pre- industrial atmospheric CO2 levels?

currently about 427 ppm (parts per million); pre- industrial levels were about 280 ppm.

How does a hypothesis become a theory?

by passing many tests and successfully explaining a series of observations.

State of the Ideal Gas Law relationships relevant to the atmosphere

pressure and density directly proportional; pressure and temperature are directly proportional; density and temperature are inversely proportional (P - pRT)

• hot air is less dense - it rises.

What is the Geosphere and what is Earth’s radius?

the solid Earth. It has a radius of 6,370 km (3,958 mi). It can affect climate over millions of years or locally through features like mountains.

• think ‘geo’ = earth/rock.

what does ozone O3 do in the stratosphere?

it absorbs incoming UV radiation and releases the energy as heat, which raises temperatures in the stratosphere and shield Earth’s Surface from harmful UV.

• UV → heat conversion

How does atmospheric density change with altitude?

it decreases exponentially. for every 5.6 km of ascent, there is half the atmospheric mass of the layer you started from.

• 90% of mass is below 16 km.

what gases were in Earth’s early atmopshere?

Water vapor (H2O), Nitrogen (N2), Methane (CH4), Ammonia (NH3), Hydrogen (H2), Carbon Dioxide (CO2), and sulfur dioxide (SO2).

what is the great oxygenation event?

an event 2.5-2.0 billion years ago when cyanobacteria (photosynthetic life) released large amounts of free oxygen. First trapped in rocks (as Banded Iron formations), then building up in the atmosphere.

• Cyanobacteria were the ‘engineers’

what percentage of the atmosphere’s mass is within 30 km?

99% of the atmosphere’s mass lies within 30 km of Earth’s surface.

• Atmosphere is very thin relative to earth’s size.

why does the US have exceptional weather variety and severity?

the US has the greatest variety of weather in the world and experiences severe events (tornadoes, dust storms, hurricanes, monsoon rains) more frequently and destructively than anywhere else.

what are the six steps of the scientific method?

1) raise a question

2) collect data/observations

3) form hypotheses

4) experiment/model

5) interpret & conclude

6) share with other scientists.

where does almost all weather occur?

in the troposphere the lowest layer. Most commercial aircraft fly here too.

• ‘tropo’ = turning / changing

what are earth’s four major spheres?

• geosphere (solid earth)

• Hydrosphere (water)

• Biosphere (life)

• Atmosphere (gases)

All are interconnected.

what is partial pressure?

the hypothetical pressure a single gas would exert if it alone occupied the total volume of the mixture at the same temperature. At 5.6km altitude, each gas’s partial pressure is half its sea level value.

• (Dalton’s Law of Partial Pressures)

what defines the boundaries between atmopsheric layers?

primarily temperature patterns specifically the lapse rate (how temperature change with altitude).

what is a scientific law?

a principle (often a mathematical equation) that accurately predicts experimental outcomes — it describes what happens not why.

• laws do not explain causes

what is a radiosonde?

an instrument package attached to weather ballon that transmits atmospheric data (temperature, pressure, humidity) by radio as it ascends.

• used for upper air sounding.

What is the Montreal Protocol?

An international agreement passed in 1989 that climinated the use and production of CFCs, the chemicals responsible for destroying the ozone layer.

• 1989 CFC phaseout

what happens to meteors in the mesosphere?

they begin to burn up due to increased atmospheric friction.

• most “shooting stars” are in this layer

what does the hydrosphere include?

oceans, glaciers, groundwater, streams, lakes and clouds. About 71% of earth’s surface is ocean.

• clouds also COUNT!

what is the lapse rate?

the rate at which temperature increases or decreases with a change in altitude. The environmental lapse rate in the troposphere is -6.5*C per 1 km rises.

• normal - gets colder going up