Becky Alexander

Becky Alexander

University of Washington, Seattle


Published on Dec 15, 2016

Final paper published!

Maria's final paper was published on Nov. 9 in the open access journal Atmospheric Chemistry and Physics.  You can read the abstract and download the paper here!If you're interested but don't want ...

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Published on May 19, 2016

Paper submitted for publication!

Maria has submitted her paper for publication in a scientific journal called Atmospheric Chemistry and Physics. This is an open-access journal, which means that anyone with access to the internet ...

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Published on Jul 30, 2015

You can’t blame it on the snow

Maria has completed her model calculations and has estimates of the role of snow in the recycling of reactive nitrogen in the Uintah Basin. I wanted to share her main conclusions with you here.The ...

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Published on May 26, 2015

UW Undergraduate Research Symposium

Lauren Easley, the UW undergraduate student who spent her summer in our lab measuring snow samples from Utah, gave a presentation on her data and our initial interpretation at the UW Undergraduate ...

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Published on Mar 05, 2015

Release of 2014 Uinta Basin Winter Ozone Study (UBWOS 2014) Report

The final report has been released and is available on-line. I will briefly summarize it here.While ground-level ozone exceedances (higher ozone concentrations than the 75 ppbv limit set by the EPA...

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Published on Nov 14, 2014

Relevant open-access article

An article was published today by a group at CU Boulder on the impact of oil and gas activities on VOC (volatile organic compound) concentrations in the Northern Front Range region of Colorado.  VO...

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Published on Oct 02, 2014

Maria's poster for upcoming workshop

After a productive summer, all of our measurements are complete.  Maria and I are going to the"Workshop on Chemical Atmosphere-Snow-Sea Ice Interactions" inCambridge, UK later this month.  Her post...

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Published on Aug 21, 2014

Lab work completed!

We have been working all summer on finishing up the measurements from this campaign.  We are finished, and have used up all of our snow and aerosol samples in the processes.  We hired a UW undergra...

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Published on Jun 12, 2014

UV absorption data

In my last lab note, I explained how we do the measurements of ultra-violet (UV) absorption.  The figure below shows Maria's absorption measurements from snowpit 9.  The y-axis is depth, the black ...

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Published on Jun 02, 2014

Measuring snow absorption

One of the other measurements Maria has been performing in the lab is measurements of the amount of ultra-violet (UV) light that is absorbed by impurities (such as black carbon and dust) in the sno...

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Published on May 14, 2014

First look at the isotope data

Maria has finished running each sample twice.  She plans to do at least one more round, but yesterday we discussed the data she has collected so far at our group meeting.  Note that all of the inte...

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Published on May 09, 2014

Data quality assurance

Hi again!  Maria is still actively measuring isotopes in the UW IsoLab.  Why is it taking soooo long?  First of all, she has about 300 samples.  And you've seen how our measurement requires multipl...

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Great question. Our initial interpretation of our results has not changed. This interpretation is that the recycling of reactive nitrogen through the snow is important only after fresh snowfall. We still need to put some numbers behind this, hence the computer model calculations. The question now is, is the fresh-snow source of reactive nitrogen significant enough to increase ozone formation? That's what we hope to answer with our calculations. Our hypothesis now is that snow chemistry may be able to explain at least part of why ozone was so much higher in the 2013 campaign than in 2014. In 2013, they had frequent snowfall followed by sunlit conditions. There is a recent paper showing results from the 2013 field campaign about the importance of volatile organic compounds (VOCs) in ozone formation - VOCs are the other important ingredient for ozone formation and are emitted by leaking gas wells, among other sources. I still need to read it through carefully. When I do I can summarize the results and what it means for our current hypothesis.
Oct 03, 2014
How does natural gas fracking contribute to air pollution?
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The lighter isotopes are more easily broken apart by sunlight than the heavier isotopes because essentially the bond strength is higher for the heavier isotopes. (Another way to put it is that the zero-point energy is lower for the heavier isotopes.) This results in a 50 permil isotope fractionation, which means that the difference between what is broken apart by the sun (and subsequently released to the atmosphere) and what remains in the snow is 50 permil. This doesn't impact the outcome per se, but it provides a "signature" of snow chemistry that allows us to quantify the degree of nitrogen recycling in the snow. We are tracking two isotopes, nitrogen 14 and nitrogen 15. Isotopes are always expressed as ratios (heavy/light), so you have to measure at least two. The dust will absorb UV sunlight, which will reduce the amount of sunlight available to break apart the nitrate in the snow (which is how it is recycled back to the atmosphere). Hope this helps!
Jun 02, 2014
How does natural gas fracking contribute to air pollution?
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Looks like a great project! You have an excellent video. I will advertise this project to my donors in my next lab post later this week. Good luck!
May 14, 2014
Does fracking contaminate water with hormone disrupting chemicals?
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All of the relevant meteorological variables are being measured by other groups. So we will have this useful information for our analysis!
Jan 23, 2014
How does natural gas fracking contribute to air pollution?
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We do some measurements right in the field, others are done in the lab in Utah, and still others will be done back at the UW. I will be providing information (with pictures!) about each measurement in future lab posts. Stay tuned!
Jan 19, 2014
How does natural gas fracking contribute to air pollution?
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Hi Chris, We are using glass fiber filters. We don't know yet whether or not we will need to impregnate them with NaOH. We have so far run a field blank, and started a sample yesterday where we have two filters placed back to back. If there's no nitrate on the second filter, then we are capturing all of the nitrate. If there is nitrate on the second filter, then we will impregnate the filters. A colleague's tests reveal that impregnation is not necessary with these filters, but since this will vary with environment, we are testing here in Utah to be sure. Thanks for your interest! Becky
Jan 18, 2014
How does natural gas fracking contribute to air pollution?
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Thanks for the offer Raymond! We will let you know if we think this will be useful.
Jan 16, 2014
How does natural gas fracking contribute to air pollution?
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