Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 1

Composition and Energy AOSC 200

Tim Canty

Class Web Site: http://www.atmos.umd.edu/~tcanty/aosc200

Lecture 03Sept 5 2017

Topics for today:

•Atmospheric composition cont.• Energy transfer

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 2

Today’s Weather Map

http://www.wpc.ncep.noaa.gov/sfc/namussfcwbg.gif

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 3

Today’s Forecast

http://www.wpc.ncep.noaa.gov/national_forecast/natfcst.php

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 4

NASA Orbiting Carbon Observatory (2)

Launched July 2, 2014

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 5

NASA Orbiting Carbon Observatory (2)

https://oco.jpl.nasa.gov/

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 6

Recent Science

http://www.pmel.noaa.gov/co2/story/Ocean+Acidification

“There has been a 30% increase in the acidity of the ocean since 1700, and we now expect that by 2100, it will have become a 100% increase. This constitutes a rate of change in ocean chemistry that is 10 times anything scientists can document over the last 50 million years.”

http://newswatch.nationalgeographic.com/2014/09/02/ocean-acidification-from-domestic-to-international/

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 7

Carbon Dioxide (CO2) Cycle

Currently, there are more sources than sinks.

As a consequence, CO2 in the air is rising.

This rise is correlated with the rise in temperatures…

… but more on that in future lectures

Currently, few ways to reduce CO2

https://directory.eoportal.org/web/eoportal/satellite-missions/o/oco-2

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 8

http://www.esrl.noaa.gov/gmd/dv/iadv/graph.php?code=MLO&program=ccgg&type=ts

Actual data much “noisier” than what is shown in textbooks

Methane (CH4)

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 9

Methane Sources and Sinks

http://www.giss.nasa.gov/research/features/200409_methane/

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 10

Methane Sources and Sinks

http://www.giss.nasa.gov/research/features/200409_methane/

Methane is mainly lost by chemical reactions in the atmosphere

The carbon in methane eventually becomes CO2

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 11

Aerosols (really tiny!!!!)

Fig 1-10 Meteorology: Understanding the Atmosphere

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty

Aerosol Observations

12

Ship Tracks!SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSShhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhiiiiiiiiiiiiiiiiiiiiiiippppppppppppppppppppppppppppppppppppppppppppppppp TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTrrrrrrrrrrrrrrrrraaaaaaaaaaaaaaaaaaaaaacccccccccccccccccccckkkkkkkkkkkkksssssssssssssss!!!!!!!!

Fig 1.6: Essentials of Meteorology

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty

Aerosol Observations – Satellite

13

Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO)

http://eosweb.larc.nasa.gov/PRODOCS/calipso/featured_imagery/iceland_volcano_ash_cloud.html

April 17, 2010, CALIPSOcaptured this image ofthe Eyjafjallajökull ashcloud.

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty

Ozone

14http://www.aoas.org/article.php?story=20080522125225466

Ozone in the stratosphere absorbs UV radiation. This is good!!!

Ozone at the surface (a.k.a. Smog!) is a pollutant. This is bad!!!

15

Temperature Scales

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

Fig 2.2: Essentials of Meteorology

Celsius (centigrade): melting point of water is 0°C and the boiling point is 100°C.

Fahrenheit: melting point of water is 32°F and the boiling point is 212°F.

Kelvin: similar to Celsius but the coldest temperature is 0K. (Kelvin scale never goes negative)

16

Energy Transfer

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

Fig 2.3: Essentials of Meteorology

17

Latent Heat

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

Latent heat: the heat required to melt or evaporate a substance

Ice in the cooler absorbs heat from the drinks

Result: the ice melts while the drinks stay cold

18

Latent Heat

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

Latent heat: the heat required to melt or evaporate a substance or the heat given off when something condenses or freezes

When water freezes or condenses, the latent heat is released back into the environment

Fig 2.4: Essentials of Meteorology

As water condenses to form a cloud, all of the heat that went into evaporating the water is released to the air.

Clouds warm the air inside the cloud.

Amount of energy released equivalent to a small nuke

19

Specific Heat

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

The specific heat of a substance is the amount of heat required to increase the temperature of 1 gram of the substance 1° C

Table 2-1 Meteorology: Understanding the Atmosphere

Water takes longer to heat (and longer to cool) than dirt

20

Energy Transfer: Conduction

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

• Conduction – requires contact, energy transferred from molecule to molecule

• Air is not a good conductor

• Metals are excellent conductors

• Very important at Earth’s surface

21

Energy Transfer: Convection

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

• Convection – energy transferred by movement of fluids (in science, air is considered a fluid)

• Surface energy transferred upward by convection

• “Hot air rises and cool air sinks”

• Lava lamps are a good example of convection

22

Energy Transfer: Convection

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

Fig 2.6: Essentials of Meteorology

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty

Temperature and Density

http://www.our-planet-earth.net/learning/3c.html

As temperature rises and the parcel expands the air inside the parcel gets less dense

(all of the air molecules are spread out over a larger volume)

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty

Temperature and Density

http://www.our-planet-earth.net/learning/3c.html

Surrounding air is denser and heavier and sinks

The less dense air is pushed up by the sinking, heavy air. “The less dense air floats” or

“Hot air rises, cold air sinks”

25

Energy Transfer: Convection

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

Fig 2.7: Essentials of Meteorology

Rising, hot air creates a convective circulation cell called a thermal

Thermals will eventually spread out, sink and move back to the starting point creating wind

26

Energy Transfer: Advection

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

Advection – horizontal movement of air (a.k.a. wind)

Fig 2-4 Meteorology: Understanding the Atmosphere

27

Rising and Sinking Air

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

Fig 2.U1: Essentials of Meteorology

Air that is pushed upward will expand and cool down Air that sinks will contract and heat up

28

Energy Transfer

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

Radiative Heat – heating due to electromagnetic radiation

called radiation but is different from nuclear radiation

29

Electromagnetic Spectrum

Copyright © 2014 University of Maryland. This material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty.

Spectrum: range of valuesWavelength: length of one wave ( , lambda)

Fig 2.8: Essentials of Meteorology

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 30

Electromagnetic Spectrum

Fig 2-7 Meteorology: Understanding the Atmosphere

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 31

The energy from the Sun peaks at 0.5 m (the visible portion of the spectrum)

Fig 2.9: Essentials of Meteorology

Solar Spectrum

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 32

Not all radiation makes it to the surface (this is a good thing!)http://imagine.gsfc.nasa.gov/Images/science/EM_spectrum_atmosphere.jpg

Copyright © 2017 University of MarylandThis material may not be reproduced or redistributed, in whole or in part, without written permission from Tim Canty 33

The energy from the Sun peaks at 0.5 m (the visible portion of the spectrum)The energy from the Earth peaks at 10 m (in the infrared portion)

Fig 2.10: Essentials of Meteorology

Solar Spectrum