Side effects

Last night, I noticed that the soap was not lathering.  Huh?  What happened to my soap?  Then I realized it wasn't the soap, it was the water!

We received significant rainfalls of .75" and then .5" in the last 72 hours.  I pulled this graphic from the Water Resources Precipitation Page.

I recalled that our local water district changes water supply depending on conditions (economic and natural).  The rainfall this week probably recharged our local aquifer just enough to enable us to draw (very hard) well water out of our underground aquifer instead of purchasing (moderately hard) imported river water.

To meet the needs of our customers in Hermosa Beach, Redondo Beach, and the Hollywood Riviera section of Torrance, we use a combination of local groundwater pumped from the West Coast groundwater basin and purchased surface water. The surface water is imported by the Metropolitan Water District of Southern California (MWD) from the Colorado River and the State Water Project in northern California.

Learn more about our aquifer and water recycling at World Water Day 2012 and Walking My Watershed.

We planted a line of 10 camellia bushes along the north facing edge of our back yard/patio. A portion of our neighbor's townhouse roof drains onto that area so it gets double the rainfall. The camellias responded well to the rain and cold weather. Stay tuned for pictures.

Ship Tracks 3

Cliff Mass posted some ship tracks pictures in Strange lines over the northeast pacific.  He showed examples from the GOES (the G stands for geostationary) satellite, which flies over the equator.  The imagery at high latitudes can be distorted. I was surprised at the lack of distortion at Seattle's latitude.

He also showed a swath image from MODIS instrument on the polar-orbiting Terra satellite at 20:05 UT.  Below that, you can see the next granule* in the satellite data stream, off the coast of California, at 20:10 UT.

The ship track region is more centered in this granule from the MODIS instrument on Terra's twin, Aqua.

I'm so grateful that professor Mass kept NASA's name for the image files when he uploaded them on his blog.  That made it easy for me to find the date and time of the files.

For instance, the filename

crefl1_143.A2013015200500-2013015201000.2km.jpg

says the image was taken off Terra in 2013 on Julian Day 015 at 20:05 to 20:10 UT. It's the 2 km resolution file. To look at it in higher resolution, set your browser to

http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/realtime.cgi

and then use the pulldown menu to toggle to January 15.  Visit that link to see the images in fantastic 250 meter resolution.

BTW, days are numbered sequentially from 1 to 365 in a Julian calendar.  It's much easier than keeping track of months and dates in software.  January is easy because the Julian day is just the date.  But, for subsequent months, this Julian day calendar comes in handy.

* NASA downloads and processes satellite data in chunks they call granules.  Whenever you shoot a continuous movie, you have to chunk it down somehow, and granule is a good, descriptive name.

Links:

• Ship tracks and our changing weather in which I explained what ship tracks are and why you should care.
• Ship Tracks 2 discusses the legal framework for controlling ship pollution.

Done and done!

2 final exams in one week. Add volunteer work at my daughter's school: math tutoring and math team coaching 3 times each, nutrition docent for two classes and staffing the CSA booth at the school wellness fair.  I was a stress monster this past week.

Oh, I also ordered supplies for the sets for the school play and made half of my daughter's costume.

How did I do?  Grade wise, I did ok.  Keeping my cool and not snapping at people?  Room for improvement.

CS 600x, Intro to Computer Science and Programming (with Python), allows students to resubmit homework code many times until the software passes the suite of software tests.  Thus, 100% on homework is not difficult to attain. The exams, however, are not so easy and offer more limited checks.  I passed the course even before the final so there was less stress.

PH207x, Biostatistics and Epidemiology, gave much more limited checks (only one try at vaguely-worded multiple choice problems--even for homework), so I wasn't sure I would pass.  I needed 78% on the final to attain the 85% overall average required to pass.  Fortunately, the final was not any harder than a typical homework from the latter half of the class.  Whew.

Biostats is definitely a class that starts out easy and then builds to some very deep and difficult stuff.  Some favorite things I learned:

• The visual explanation of what's going on beneath "turn the crank" linear regression.  I've never seen it presented that way before.  Why didn't someone explain that to me 25 years ago?
• What are the odds?  I didn't know and I never before cared because I preferred my statistics stated in probabilities.  But, I had never before pondered the beautiful symmetry of odds tables. Now, I will keep both odds and probabilities in my toolkit and use the one appropriate for the situation.
• The application of Bayes' theorem to experimental design.  Suppose you are interested in cancer research, but it's unethical to give people cancer just so you can study them.  With Bayes'  theorem, you can just flip the conditional probabilities around to design an experiment that you can perform without giving people cancer (or some other disease).
• Soft skills are more highly valued in the biological sciences than in the physical sciences.  One professor began .each. lecture segment with, "Welcome back everybody.  Thank-you for coming."  I can't recall any physics professor saying that*.

* The nicest thing any physics professor said was when I asked him why he always picked on me in class.  He looked kind of taken back and then replied, "Because you are my benchmark student. You are the kind of student that should be able to follow the lecture, if I am doing my job.  So, if you are confused, then I know I have to backtrack."

He further went on that he can see the confusion written plainly on my face, and the (mostly much taller) male students leave a front row seat open for me, which makes for a handy benchmark student.