Category Archives: York University

How I Ended Up in Geophysical Fluid Dynamics

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How I Ended Up in Geophysical Fluid Dynamics

Lately, I’ve been disclosing the various biases I bring to practicing and enabling Data Science. Motivated by my decision to (finally) self-curate an online, multimedia portfolio, I felt such biases to be material in providing the context that frames this effort. Elsewhere, I’ve shared my inherently scientific bias. In this post, I want to provide additional details. These details I’ve been able to extract verbatim from a blog post I wrote for Bright Computing in January 2015; once I’d settled on geophysics (see below), I aspired to be a seismologist … but, as you’ll soon find out, things didn’t pan out quite the way I’d expected:

I always wanted to be a seismologist.

Scratch that: I always wanted to be an astronaut. How could I help it? I grew up in suburban London (UK, not Ontario) watching James Burke cover the Apollo missions. (Guess I’m also revealing my age here!)

Although I never gave my childhood dream of becoming an astronaut more than a fleeting consideration, I did pursue a career in science.

As my high-school education drew to a close, I had my choices narrowed down to being an astronomer, geophysicist or a nuclear physicist. In grade 12 at Laurier Collegiate in Scarboro (Ontario, not UK … or elsewhere), I took an optional physics course that introduced me to astronomy and nuclear physics. And although I was taken by both subjects, and influenced by wonderful teachers, I dismissed both of these as areas of focus in university. As I recall, I had concerns that I wouldn’t be employable if I had a degree in astronomy, and I wasn’t ready to confront the ethical/moral/etc. dilemmas I expected would accompany a choice of nuclear physics. Go figure!

And so it was to geophysics I was drawn, again influenced significantly by courses in physical geography taught by a wonderful teacher at this same high school. My desire to be a seismologist persisted throughout my undergraduate degree at Montreal’s McGill Universitywhere I ultimately graduated with a B.Sc. in solid Earth geophysics. Armed with my McGill degree, I was in a position to make seismology a point of focus.

But I didn’t. Instead, at Toronto’s York University, I applied Geophysical Fluid Dynamics (GFD) to Earth’s deep interior – mostly Earth’s fluid outer core. Nothing superficial here (literally), as the core only begins some 3,000 km below where we stand on the surface!

Full disclosure: In graduate school, the emphasis was GFD. However, seismology crept in from time to time. For example, I made use of results from deep-Earth seismology in estimating the viscosity of Earth’s fluid outer core. Since this is such a deeply remote region of our planet, geophysicists need to content themselves with observations accessible via seismic and other methods.

From making use of Apache Spark to improve the performance of seismic processing (search for “Reverse-Time Seismic Migration” or “RTM” in my Portfolio), to the analysis of ‘seismic data’ extracted from Twitter (search for “Twitter”in my Portfolio), seismology has taken center stage in a number of my projects as a practitioner of Data Science. However, so has the geophysical fluid dynamics of Earth’s mantle and outer core. Clearly, you can have your geeky cake and eat it too!

Recent Workshop: Nurturing Quantitative Skills for the Physical Sciences through use of Scientific Models

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unst_water_oilA few weeks back, I delivered a workshop at a conference focused on online learning. Unfortunately, abstracts were not made available via the event’s web site. In lieu of directing you elsewhere then, below is the abstract I submitted:

Nurturing Quantitative Skills for the Physical Sciences through use of Scientific Models

L. I. Lumb
Division of Natural Science, Faculty of Science, York University
Toronto, Ontario, Canada

With numerous scientists asserting that we have entered into The Anthropocene, a ‘brand new’ Geologic Epoch that underscores human impact on planet Earth, there has arguably never been a more relevant time for literacy in the physical sciences. Complicating this, however, is the implied need for quantitative skills demanded of those who seek to have more than a superficial degree of literacy in matters relating to climate or global change. Grounded by direct, personal experience in teaching science to non-scientists at the undergraduate university level, and independently validated by academic research into Science Technology Engineering Math (STEM) related programs and subjects, mastery of even the most-basic quantitative skills presents a well-established challenge in engaging learners at levels beyond the quantitatively superficial – a challenge that appears to be increasingly the case with the arriving cohort of undergraduates each Fall. In an effort to systematically develop and encourage proficiency in quantitative skills in data-rich courses in the physical sciences, a number of scientific models have been introduced by the author. Ranging from embarrassingly simple physical models using rice to investigate relative humidity in Earth’s atmosphere, to software-based models that employ spreadsheets to elucidate aspects of climate and global change, the use of scientific models presents intriguing challenges and opportunities for both instructors and students; needless to state, these challenges and opportunities can be significantly exacerbated in courses that are delivered online to numbers in excess of 100 students. After an introduction of scientific models as a pedagogical vehicle for nurturing quantitative skills, emphasis shifts to the sharing of real-world experiences with this approach in relatively large, online courses in physical sciences taught at the undergraduate level to non-majors (and therefore non-scientists). In ultimately working towards the primary example of a relatively simple, yet scientifically appropriate spreadsheet model for the Paris Climate Agreement, participants’ involvement will be scaffolded through use of other examples of models that have also been used in practice. Participants will also be encouraged to engage in a dialogue that compares and contrasts these models with more traditional approaches (e.g., formal essays). Finally, armed with some context for models as a pedagogical vehicle for quantitatively enhancing student engagement, participants will be guided through exercises that will allow them to develop their own models for their own teaching and learning requirements – whether their interests fall within or beyond scientifically oriented disciplines.

As you can see, I have a vested interest in nurturing quantitative skills, and models is one of the vehicles I make use of. If you share similar interests or better yet, if you have ideas as to what’s worked for you, please feel free to comment.

Guest Post: Four Tips for Taking Great Cloud Photos

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Kevin Li took NATS 1780 two years ago. In addition to maintaining an interest in weather and climate, Kevin remains an accomplished and enthusiastic photographer. I asked Kevin if he might have a few cloud-photo tips to share with the students currently taking NATS 1780 at Toronto’s York University. Here’s his response:

Four Tips for Taking Great Cloud Photos:

  • It starts with composition of the photo (what you include in your photo, mostly clouds with some landscape or just clouds and the sky?) good composition will show us location, approximate time of the day, and weather conditions (which could explain why the shape of the clouds are the way they are)
  • Head out in the early morning around sunrise and around sunset. This will add some warm colours to your photos especially around sunset. You will notice that the clouds are more visible and distinct in those times of the day rather than mid-day
  • Focusing of the camera will be crucial and will depend on your camera. The focus should be placed on the cloud you want to photograph. This allows the camera to adjust the lighting to avoid over exposure and or under exposure
  • Lastly, if you are using a smartphone, your phone might have a feature that will boost the colour saturation levels. This feature will make some if your photos pop! For those with dslrs and point and shoot cameras, this can be done in post-production or maybe in-camera depending on the camera you have.

It’s not about the camera, but the person who is behind the camera! 🙂

Note for DSLR users only: A circular polarizer will help on those bright sunny days. If you don’t have one, use a high shutter speed or decrease the aperature size to f8 or smaller.

Many thanks to Kevin for sharing this excellent advice!

If you have additional tips to share, please feel free to add a comment. If you have a question, I’m sure I can persuade Kevin to answer it.

Current Events in the Classroom: Experiments on Mars-Like Clouds Stimulate the Learning Process

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Everyone has an appreciation for humidity and clouds … However, when you seek to understand humidity and clouds from the scientific perspective, `things get technical‘ in a hurry! As someone who attempts to share science with non-scientists, it’s wonderful to be able to work current events into the (physical/virtual) classroom. Some recent experimental results, aimed at simulating Martian-style clouds, allow for a highly topical teachable moment.

For the details, please see below my recent post (via Moodle) to my Weather and Climate class at Toronto’s York University:

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Now, if only I could have such a cloud chamber in the (virtual) classroom …

Pencasting During Lectures in Large Venues

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In a recent post on pencasting as a way of teaching/learning weather and climate, I stated:

Monday (October 1, 2012), I intend to use a pencast during my lecture – to introduce aspects of the stability of Earth’s atmosphere. I’ll try to share here how it went. For this intended use of the pencast, I will use a landscape mode for presentation – as I expect that’ll work well in the large lecture hall I teach in. I am, however, a little concerned that the lines I’ll be drawing will be a little too thin/faint for the students at the back of the lecture theatre to see …

I followed through as advertized (above) earlier today.

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My preliminary findings are as follows:

  • The visual aspects of the pencast are quite acceptable – This is true even in large lecture halls such as the 500-seat Price Family Cinema at York University (pictured above) in Toronto, Canada where I am currently teaching. I used landscape mode for today’s pencast, and zoomed it in a little. A slightly thicker pen option would be wonderful for such situations … as would different pen colours (the default is green).
  • The audio quality of the pencasts is very good to excellent – Although my Livescribe pen came with a headset/microphone, I don’t use it. I simply use the built-in microphone on the pen, and speak normally when I am developing pencasts. Of course, the audio capabilities of the lecture hall I teach in are most excellent for playback!
  • One-to-many live streaming of pencasts works well – I streamed live directly from myLivescibe today. I believe the application infrastructure is based largely on Adobe Flash and various Web services delivered by Web Objects. Regardless of the technical underpinnings, live streaming worked well. Of course, I could’ve developed a completely self-contained PDF file, downloaded this, and run the pencast locally using Adobe Reader.
  • Personal pencasting works well – I noticed that a number of students were streaming the pencast live for themselves during the lecture. In so doing, they could control interaction with the pencast.

Anecdotally, a few students mentioned that they appreciated the pencast during the break period – my class meets once per for a three-hour session.

Although I’ve yet to hear this feedback directly from the students, I believe I need to:

  • Decrease the duration of pencasts – Today’s lasts about 10 minutes
  • Employ a less-is-more approach/strategy – My pencasts are fairly involved when done …
  • Experiment with the right balance of speaking to penning (is that even a word!?) – Probably a less-is-more approach/strategy would work well here for both the penned and spoken word …

Finally, today’s pencast on the basics of atmospheric stability:

  • Previous approach – Project an illustration taken directly from the course’s text. This is a professionally produced, visually appealing, detailed, end-result, static diagram that I embedded in my presentation software (I use Google Docs for a number of reasons.) Using a laser pointer, my pedagogy called for a systematic deconstruction this diagram – hoping that the students would be engaged enough to actually follow me. Of course, in the captured versions of my lectures, the students don’t actually see where I’m directing the laser pointer. The students have access to the course text and my lecture slides. I have no idea if/how they attempt to ingest and learn from this approach.
  • Pencasting – As discussed elsewhere, the starting point is a blank slate. Using the pencasting technology, I sketch my own rendition of the illustration from the text. As I build up the details, I explain the concept of stability analyses. Because the sketch appears as I speak, the students have the potential to follow me quite closely – and if they miss anything, they can review the pencast after class at their own pace. The end result of a pencast is a sketch that doesn’t hold a candle to the professionally produced illustration provided in the text and my lecture notes. However, to evaluate the pencast as merely a final product, I believe, misses the point completely. Why? I believe the pencast is a far superior way to teach and to learn in situations such as this one. Why? I believe the pencast allows the teacher to focus on communication – communication that the learner can also choose to be highly receptive to, and engaged by.

I still regard myself as very much a neophyte in this arena. However, as the above final paragraphs indicate, pencasting is a disruptive innovation whose value in teaching/learning merits further investigation.

Teaching/Learning Weather and Climate via Pencasting

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I first heard about it a few years ago, and thought it sounded interesting … and then, this past Summer, I did a little more research and decided to purchase a Livescribe 8 GB Echo(TM) Pro Pack. Over the Summer, I took notes with the pen from time-to-time and found it to be somewhat useful/interesting.

Just this week, however, I decided it was time to use the pen for the originally intended purpose: Making pencasts for the course I’m currently teaching in weather and climate at Toronto’s York University. Before I share some sample pencasts, please allow me to share my findings based on less than a week’s worth of `experience’:

  • Decent-quality pencasts can be produced with minimal effort – I figured out the basics (e.g., how to record my voice) in a few minutes, and started on my first pencast. Transferring the pencast from the pen to the desktop software to the Web (where it can be shared with my students) also requires minimal effort. “Decent quality” here refers to both the visual and audio elements. The fact that this is both a very natural (writing with a pen while speaking!) and speedy (efficient/effective) undertaking means that I am predisposed towards actually using the technology whenever it makes sense – more on that below. Net-net: This solution is teacher-friendly.
  • Pencasts compliment other instructional media – This is my current perspective … Pencasts compliment the textbook readings I assign, the lecture slides plus video/audio captures I provide, the Web sites we all share, the Moodle discussion forums we engage in, the Tweets I issue, etc. In the spirit of blended learning it is my hope that pencasts, in concert with these other instructional media, will allow my TAs and I to `reach’ most of the students in the course.
  • Pencasts allow the teacher to address both content and skills-oriented objectives – Up to this point, my pencasts have started from a blank page. This forces me to be focused, and systematically develop towards some desired content (e.g., conceptually introducing the phase diagram for H2O) and/or skills (e.g., how to calculate the slope of a line on a graph) oriented outcome. Because students can follow along, they have the opportunity to be fully engaged as the pencast progresses. Of course, what this also means is that this technology can be as effective in the first-year university level course I’m currently teaching, but also at the academic levels that precede (e.g., grade school, high school, etc.) and follow (senior undergraduate and graduate) this level.
  • Pencasts are learner-centric – In addition to be teacher-friendly, pencasts are learner-centric. Although a student could passively watch and listen to a pencast as it plays out in a linear, sequential fashion, the technology almost begs you to interact with it. As noted previously, this means a student can easily replay some aspect of the pencast that they missed. Even more interestingly, however, students can interact with pencasts in a random-access mode – a mode that would almost certainly be useful when they are attempting to apply the content/skills conveyed through the pencast to a tutorial or assignment they are working on, or a quiz or exam they are actively studying for. It is important to note that both the visual and audio elements of the pencast can be manipulated with impressive responsiveness to random-access input from the student.
  • I’m striving for authentic, not perfect pencasts – With a little more practice and some planning/scripting, I’d be willing to bet that I could produce an extremely polished pencast. Based on past experience teaching today’s first-year university students, I’m fairly convinced that this is something they couldn’t care less about. Let’s face it, my in-person lectures aren’t perfectly polished, and neither are my pencasts. Because I can easily go back to existing pencasts and add to them, I don’t need to fret too much about being perfect the first time. Too much time spent fussing here would diminish the natural and speedy aspects of the technology.

Findings aside, on to samples:

  • Calculating the lapse rate for Earth’s troposphere – This is a largely a skills-oriented example. It was my first pencast. I returned twice to the original pencast to make changes – once to correct a spelling mistake, and the second time to add in a bracket (“Run”) that I forgot. I communicated these changes to the students in the course via an updated link shared through a Moodle forum dedicated to pencasts. If you were to experience the updates, you’d almost be unaware of the lapse of time between the original pencast and the updates, as all of this is presented seamlessly as a single pencast to the students.
  • Introducing the pressure-temperature phase diagram for H2O – This is largely a content-oriented example. I got a little carried away in this one, and ended up packing in a little too much – the pencast is fairly long, and by the time I’m finished, the visual element is … a tad on the busy side. Experience gained.

Anecdotally, initial reaction from the students has been positive. Time will tell.

Next steps:

  • Monday (October 1, 2012), I intend to use a pencast during my lecture – to introduce aspects of the stability of Earth’s atmosphere. I’ll try to share here how it went. For this intended use of the pencast, I will use a landscape mode for presentation – as I expect that’ll work well in the large lecture hall I teach in. I am, however, a little concerned that the lines I’ll be drawing will be a little too thin/faint for the students at the back of the lecture theatre to see …
  • I have two sections of the NATS 1780 Weather and Climate course to teach this year. One section is taught the traditional way – almost 350 students in a large lecture theatre, 25-student tutorial groups, supported by Moodle, etc. In striking contrast to the approach taken in the meatspace section, is the second section where almost everything takes place online via Moodle. Although I have yet to support this hypothesis with any data, it is my belief that these pencasts are an excellent way to reach out to the students in the Internet-only section of the course. More on this over the fullness of time (i.e., the current academic session.)

Feel free to comment on this post or share your own experiences with pencasts.

Synthetic Life and Evolution of Earth’s Second Atmosphere

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I have the pleasure of teaching the science of weather and climate to non-scientists again this Fall/Winter session at Toronto’s York University. In the Fall 2011 Term, time was spent discussing the origin and evolution of Earth’s atmosphere. What follows is a post I just shared with the class via Moodle (our LMS):
Photosynthesizing anaerobic lifeforms in Earth’s oceans were likely responsible for systematically enriching Earth’s atmosphere with respect to O2. Through chemical reactions in Earth’s atmosphere, O3 and the O3 layer were systematically derived from this same source of O2. The O3 layer’s ability to minimize the impact of harmful UV radiation, in tandem with the ascent of [O2] to current values of about 21% by volume, were and remain crucial to life as we experience it today.

In tracing the evolution of Earth’s second atmosphere from a composition based on volcanic outgassing to its present state, the role of life was absolutely critical.

On my drive home tonight after today’s lecture, I happened upon a broadcast regarding synthetic life on CBC Radio‘s Ideas. Based upon annotated excerpts from a Craig Venter lecture, this broadcast is well worth the listen in and of itself. And although I’m no life scientist, I can’t help but predict that Venter’s work will ultimately lead to refinements, if not a complete rewrite, of life’s role in the evolution of Earth’s second atmosphere.
If you have any thoughts on this prediction, please feel free to share them here via a comment.

Triple and Quadruple Rainbows: Theory Meets Practice

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Last Fall 2010/Winter 2011, I taught the science of weather and climate to non-scientists at Toronto’s York University.

During the Fall semester, a unit of NATS 1780 focused on atmospheric optics. Not surprisingly, rainbows were one of the topics that received attention.

By the end of this unit, students understood that rainbows are the consequence of a twofold optical manipulation of sunlight:

  • Raindrops bend sunlight.  Not only do raindrops bend (refract) sunlight, they do so with extreme prejudice. Blue light gets bent the most, red the least. In other words, this is a wavelength-based prejudice: The shorter the wavelength, the more the light is bent. This highly selective refraction is known as dispersion. Like a prism then, raindrops allow for the individual colours that comprise visible light to be made evident.
  • Raindrops reflect sunlight.  Inside the raindrop, reflection occurs. In fact, multiple reflections can occur. And if all of the angles are just right, these reflections can remain contained within the raindrop. This is known as the phenomenon of Total Internal Reflection (TIR).
The combined effect of bending and internally reflecting is best understood with a diagram. Note in this Wikipedia diagram that sunlight interacts with the air/raindrop boundary upon entry, gets reflected internally once, and then again interacts with the raindrop/air boundary upon exit from the raindrop. Taken together, the result is a single rainbow.

How are double rainbows produced? By increasing the number of internal reflections to two.

Single and double rainbows are relatively easily observed.

On the Fall 2010 Exam in NATS 1780, I included the question:
If it were possible, how would a tertiary (i.e., third)
rainbow be produced?
A number of students correctly answered that three reflections internal to the raindrop would be required to produce such a phenomenon.

Although I had intended this to be a question of theoretical merit only, I was delighted to learn that both triple and quadruple rainbows have been observed – in other words, they are no longer just a theoretical possibility. (Quadruple rainbows would require four internal reflections.)

Alas, I’ve only ever been able to capture single and double rainbows … My personal quest for the more elusive triple and quadruple rainbows continues …

Targeting Public Speaking Skills via Virtual Environments

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Recently I shared an a-ha! moment on the use of virtual environments for confronting the fear of public speaking.

The more I think about it, the more I’m inclined to claim that the real value of such technology is in targeted skills development.

Once again, I’ll use myself as an example here to make my point.

If I think back to my earliest attempts at public speaking as a graduate student, I’d claim that I did a reasonable job of delivering my presentation. And given that the content of my presentation was likely vetted with my research peers (fellow graduate students) and supervisor ahead of time, this left me with a targeted opportunity for improvement: The Q&A session.

Countless times I can recall having a brilliant answer to a question long after my presentation was finished – e.g., on my way home from the event. Not very useful … and exceedingly frustrating.

I would also assert that this lag, between question and appropriate answer, had a whole lot less to do with my expertise in a particular discipline, and a whole lot more to do with my degree nervousness – how else can I explain the ability to fashion perfect answers on the way home!

image006Over time, I like to think that I’ve approved my ability to deliver better-quality answers in real time. How have I improved? Experience. I would credit my experience teaching science to non-scientists at York, as well as my public-sector experience as a vendor representative at industry events, as particularly edifying in this regard.

Rather than submit to such baptisms of fire, and because hindsight is 20/20, I would’ve definitely appreciated the opportunity to develop my Q&A skills in virtual environments such as Nortel web.alive. Why? Such environments can easily facilitate the focused effort I required to target the development of my Q&A skills. And, of course, as my skills improve, so can the challenges brought to bear via the virtual environment.

All speculation at this point … Reasonable speculation that needs to be validated …

If you were to embrace such a virtual environment for the development of your public-speaking skills, which skills would you target? And how might you make use of the virtual environment to do so?

Confronting the Fear of Public Speaking via Virtual Environments

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Confession: In the past, I’ve been extremely quick to dismiss the value of Second Life in the context of teaching and learning.

Even worse, my dismissal was not fact-based … and, if truth be told, I’ve gone out of my way to avoid opportunities to ‘gather the facts’ by attending presentations at conferences, conducting my own research online, speaking with my colleagues, etc.

So I, dear reader, am as surprised as any of you to have had an egg-on-my-face epiphany this morning …

Please allow me to elaborate:

It was at some point during this morning’s brainstorming session that the egg hit me squarely in the face:

Why not use Nortel web.alive to prepare graduate students for presenting their research?

Often feared more than death and taxes, public speaking is an essential aspect of academic research – regardless of the discipline.

image004Enter Nortel web.alive with its virtual environment of a large lecture hall – complete with a podium, projection screen for sharing slides, and most importantly an audience!

As a former graduate student, I could easily ‘see’ myself in this environment with increasingly realistic audiences comprised of friends, family and/or pets, fellow graduate students, my research supervisor, my supervisory committee, etc. Because Nortel web.alive only requires a Web browser, my audience isn’t geographically constrained. This geographical freedom is important as it allows for participation – e.g., between graduate students at York in Toronto and their supervisor who just happens to be on sabbatical in the UK. (Trust me, this happens!)

As the manager of Network Operations at York, I’m always keen to encourage novel use of our campus network. The public-speaking use case I’ve described here has the potential to make innovative use of our campus network, regional network (GTAnet), provincial network (ORION), and even national network (CANARIE) that would ultimately allow for global connectivity.

While I busy myself scraping the egg off my face, please chime in with your feedback. Does this sound useful? Are you aware of other efforts to use virtual environments to confront the fear of public speaking? Are there related applications that come to mind for you? (As someone who’s taught classes of about 300 students in large lecture halls, a little bit of a priori experimentation in a virtual environment would’ve been greatly appreciated!)

Update (November 13, 2009): I just Google’d the title of this article and came up with a few, relevant hits; further research is required.