New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Air Chemistry and Pollution

by: Jon Johns

Air Chemistry and Pollution ATOC 3500

Jon Johns

GPA 3.95

Darin Toohey

Almost Ready


These notes were just uploaded, and will be ready to view shortly.

Purchase these notes here, or revisit this page.

Either way, we'll remind you when they're ready :)

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

Darin Toohey
Class Notes
25 ?




Popular in Course

Popular in Marine Science

This 18 page Class Notes was uploaded by Jon Johns on Thursday October 29, 2015. The Class Notes belongs to ATOC 3500 at University of Colorado at Boulder taught by Darin Toohey in Fall. Since its upload, it has received 9 views. For similar materials see /class/232046/atoc-3500-university-of-colorado-at-boulder in Marine Science at University of Colorado at Boulder.


Reviews for Air Chemistry and Pollution


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 10/29/15
ATOC 3500 October 6 2006 Recap of Aerosols 39 Know there is a variety of particles present in the atmosphere and their importance to many phenomena Many sources of pariiculain matter anthropogenic generally much less than natural Classi cation of partials by size and to some ancient sources Objectives Review aerosol formaiion processes Learn about the interaction of light with particles Dlscuss the concept of visibility Aerosal Formation PM 39 Primary particles mechanical processes and natural emissions 39 Breaking waves and bubbles 39 Manufacturing Volcanic eruption Combustion biomass burning Secondary particles chemical transformation of gases Sulfate particles SOZOH M gtH303 M HSC3 02 gt H02 80 303 H20 gt H2804 stom gt H280 Or 802 particles 9 H2530 Nitrate particles N02OHM gtHN03M HM3m gt HNOM 39 Hydrocarbon particles RH 03 gt gt gt particles mmmm mnmmnmm mamw Walmwnmmmcm amatme mu IMMM quot505 my Lugome mi mu m Haze and Visibility What is haze Particulate pollution mostly small particles Haze particulates aquot PHOTOCHEMICAL Smog ozone N02 PAN although they often occur at the same time Why should we care about haze W it affects vlsibility our ability to see objects in the distance gaun small panicles can be inhaled and can lodge in lung tissue or deposit hazardous substances there FummmSodMymmmm comm Cormnartmammmeem ammmdoumcomm im lepolycydicmhydrm PMb PMarembbemnlcumuhomiolsmmm mnummidemeoflmammumnm pmbablyrehtedbPNb imrgwm mm d WERE HZngi Emil Wm 611 1mg maan 361 lm W Jr lm 9523 031 mmmj mg MEW E 7 AH hdm yeames absewev Nd Almawheve Ox Haze Dvesem WHWE UEHT hansmmed hghr p yeHnw W W Sceneved hdm damxnaled by BLuE Tvansmmed mm s shgm y veddxsh Scansved mm s We m mm Quantifying Visibility Miaibjllncjhe ability to distinguish a black object against a white background Practically speaking it is the ease with which features along the skyline can be distinguished from the sky itself Extingtigu Removal of light from a path by absorption andor scattering It is not always possible or practical to separate out the two processes ultimately we really only care about how much light reaches the observer Beer39s Law I ln axptomnl omnl mgg gw a m 353 A I 8 Hg a Since a for absorption and scattering are likely to be different we typically lump together these terms together I I0 exM ab a is called the quotextinction coef cient and has units of cmquot 9mm Another unit of measure useful when the path length is not known or ls illde ned l In expo Optical depth t is a dimensionless number and can be thought of as the product of crosssection and column amount tohaN Optical depth also describes the probability of removal of light 1 lt 01 little attenuation 01 lt 1 lt 05 attenuation s t c gt 1 most light removed Emblem The optical depth of the stratospheric aerosol layer is typically about 1 x 10 for wavelengths of 1 um Following the eruption of the Mt Pinatubo volcano in 1991 the optical depth at1 um increased to 1 x 10 2 How much more or less infrared light got through this layer Mat do you think the consequences of this change might be Answer From the restatement of Beer39s Law above We know that Illa equot where the ratio Ill represents the fraction of light getting to the detector or observer We can make use of an approximation here for small values of x 9 1 E 3 Both values for the optical depth are quite small so we can approximate Typical Ill WW 1 00001 1 Postvolcano lilo elt m1 1 001 099 The amount of light getting through the aerosol layer decreased following the volcanic eruption because the optical depth increased Approximately 1 less light got through That missing 1 had to go somewhere either be scattered by the particles or absorbed by them In this case it was likely absorbed Evidence has shown that the enhanced aerosol layer following the Pinatubo eruption was responsible for slightly increasing the temperature of the lower stratospherel Quantifying Visibility cont39d In clear air Visibility in the westem US is typically 140 miles Visibility in the eastern US is typically 90 miles Why the difference Related to relative humidity and particle composition Commonly Visibility in the western US is 35 90 miles Visibility in the eastern US is 15 a 25 miles Di erences between clear air and common values is related to total amount of particulate matter in air Total Suspended Particulate TSP Empirically 1 mil TSP250 where TSP is in pg mi How far you can really see km 393 w 1000ITSP For example PMquot standard 24hr average 1 50 pg mi Under those conditions km a 1000139 SP 67 km about 4 mi For average quotbadquot DenverBoulder conditions of 65 pg m6 km a WOOTSP 15 km about 10 mi Emblem The visibility length in a certain fog is 05 km Assuming that there are 100 spherical fog particles per cm3 and that pH20 is 1 g cma calculate the average radius of a fog droplet We learned above that visibility length is inversely related to the total suspended particulate mass 2 lOOOI SP so TSP 1000105 km 2000 pg m393 But how are we going to get from TSP to the radius ofa fog droplet What in ammation are we given We know the total mass of particles in a given velume and the total mnnber of particles in a given volume So we can determine the mass of a single particle Then we are given the density of water of which the particles are made Recall that density is massvolume thus we can determine the volume of a single patticle in this fog Since we ate told that the particles are ephen39cal we can the apply the relationship de ning the vohnne of a sphere V 431tr and calculate 139 First let s get everything in similar units 2000 pigm3 1 31 x 10 us tn100 mn 2 x1093 uni3 Then we can nd the mass of a single particle 2 x 10quot g cm cm f 100 particles 2 x 10 3 particle1 Since the density ofwater is 1 g eatquot there must be 2 x 1039quot em3 particlequot Then 139 3V41t1 3 3 2 x 10 em Mn 17 x 10quot em or about 17 pm For example The PM standard is 50 pg m3 annual average which corresponds to an extinction of e 02 knr Typical quothadquot values for DenverBoulder range from 6070 3919 m4quot fore 024 028 km


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

Kyle Maynard Purdue

"When you're taking detailed notes and trying to help everyone else out in the class, it really helps you learn and understand the I made $280 on my first study guide!"

Bentley McCaw University of Florida

"I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

Parker Thompson 500 Startups

"It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.