Susy Ellison, Aaargh Matey, How’s Your Number Sense? September 22, 2013

NOAA Teacher at Sea
Susy Ellison
Aboard NOAA Ship Rainier
September 9-26, 2013 

Mission:  Hydrographic Survey
Geographic Area:  Cold Bay, Alaska
Date:  September 22, 2013   

Weather:  current conditions from the bridge
GPS Location: 55o 15.190’ N   162o 38.035’ W
Temp: 8.6C
Wind Speed: 10 kts
Barometer: 1008.3mb
Visibility: 10 miles

You can also go to NOAA’s Shiptracker (http://shiptracker.noaa.gov/) to see where we are and what weather conditions we are experiencing.

If you want a detailed report of weather in our area, check out this link and hover over Cold Bay: http://pafc.arh.noaa.gov/index.php?index=bering   

Science and Technology Log

THE FINE ART OF STARING AT A STICK!

Why am I sitting here?  What am I looking at?

Why am I sitting here? What’s out there?

 What would you think if you saw someone bundled in warm clothing, sitting in an office chair on a pier with a pair of binoculars, a watch, and a clipboard?  Are they counting waves? Counting birds?  Keeping track of the clouds or the wind speed?  In my case it was ‘none of the above’; I was watching a measuring stick, taking measurements every 6 minutes over a period of 3 hours.  Why would anyone want to sit in a chair on a pier and stare at a stick for 3 hours?

The answer, of course, is science! Now, this wasn’t just any sort of stick.  This tide staff was attached to an automatic tide gauge that the crew of the Rainier installed during their last visit to Cold Bay in August.  That gauge has been recording tidal data that is used during their hydrographic survey work.  But, as with any automatic data-gathering device, it is critical to field check its accuracy, both in measuring and reporting the data.  The gauge measures the depth of the water column at 6-minute intervals, using the pressure of the water column as a proxy for that depth (deeper water exerts a greater pressure on the subsurface opening of the gauge—for a more in-depth explanation, you can check out my blog from September 13th).  My job was to stare at the staff for a period of 1 minute every 6 minutes, and determine both the highest and lowest height of the water lapping at the markings on the stick.

This might sound easy, but it wasn’t quite so simple.  The wind was howling and the waves were bouncing—it took a little practice to make what I hoped was an accurate estimate of both the high mark and the low.  After each observation period I recorded these numbers on a spreadsheet and then spent the next few minutes watching the birds that were flying and landing on the water.  Then—back to the stick!  The tide was dropping with each observation and the winds died down enough to make it a little easier to read the high and low points on each successive 6 minute interval.  By the 10th observation I had it figured out!

NOAA Corps ENS Clark demonstrates proper form for tide gauge observation.

NOAA Corps ENS Clark demonstrates proper form for tide gauge observation.

Picture trying to read this from far away as the water bounces up and down the staff.

Picture trying to read this from far away as the water bounces up and down the staff.

The data I collected was matched against data from the tide gauge for that same time period.  I was pleased to see that my observations matched those of the gauge.  Apparently, both of ‘us’ are good observers of tidal changes.  Now I have one more skill to add to my resume!!

This graph compares my observations with that of the tide gauge.  What do we observe vs. what does a computer measure?

This graph compares my observations with that of the tide gauge. What do we observe vs. what does a computer measure?

AAARGH, MATEY—HOW’S YOUR NUMBER SENSE?   APPLIED MATH ON THE HIGH SEAS  

It would be hard to find an aspect of life aboard the Rainier that doesn’t involve number sense or math.  This ship’s daily operations run like clockwork; breakfast from 0700-0800, Safety Meeting and deployment of the launches at 0800, lunch from 1130 to 1230, launches return at 1630, dinner from 1700 to 1800, etc.  Pretty simple numbers to deal with, but numbers, nonetheless.

That’s just the start of your applied math tour of the high seas. Maybe you have to figure out how much diesel fuel the ship has onboard.  Since the Rainier uses 20,000-40,000 gallons for each leg of its cruise, it would be pretty horrible to run out before you reached port.  The ship’s tanks can hold around 100,000 gallons of diesel and are usually filled to within 95% of that.  Unlike your car, there’s no fuel gauge on this ship.  So how do you figure out how much fuel is in the tank?  It’s time for some simple, yet essential math. First, you need to know the volume of the fuel tank.   Get out your math books and find that formula.  Then, you take what is called a ‘sounding’—you bang on the tank to determine the level of fuel.  Not too complicated, but certainly a skill that takes some practice.  So, now you know the total volume of the tank as well as the actual height of your fuel; if you figure out the volumes for each and do some subtraction, you can find out what percentage of your total fuel is still in the tank.

We might all be better at determining volume and percent if we had images of a fuel tank on the dashboards of our cars instead of a linear gauge reading ‘E’ to ‘F’! What about drinking water?  The Rainier uses a distillation system to create fresh water from seawater.  There are tanks down in the engine room where seawater is heated to the boiling point.  There’s a little more math and science in this process—the pressure in the distillation tank is lowered, to lower the boiling point (if you’ve ever camped at a high elevation you might notice that water boils at a lower temperature—your tea might not be quite as hot when it’s boiling) so the water doesn’t have to be heated quite so much to get it to boil.  This steam is captured in the upper portion of the distiller and cooled using cold seawater that flows through pipes.  The condensation from cooling is captured, filtered to remove any impurities, and distributed as fresh water to all onboard.  The ship uses around 2500 gallons of water each day.

Here's where all our fresh water is produced.  This distiller takes in seawater and, through boiling and condensation, produces fresh water.

Here’s where all our fresh water is produced. This distiller takes in seawater and, through boiling and condensation, produces fresh water.

If you’re running the galley it’s essential to calculate how much food you’ll need for each leg of the trip.  No one wants to do without their morning eggs if your multiplication is off and you ‘forget’ to buy a few dozen.  Taking a recipe that is designed to feed 8 people and ‘upsizing’ it for 48 people takes a bit of mathematical manipulation.  Just planning a menu for a three-week journey takes some mathematical thinking as you visualize the weeks, days, meals, and individual ingredients needed for those meals.  You have to factor in a few variables; which foods have the longest shelf life, when do you have to switch from fresh to frozen or to canned foods, how much food does the ‘average’ person eat, and what about all those people with food allergies or preferences?  While this might not sound quite as earth-shattering as using a detailed computer program to concatenate multiple data files, this is math that counts—especially when you’re feeding a boatload of hungry crew.

This is a glimpse of some of the supplies stored on the ship.

This is a glimpse of some of the supplies stored on the ship.

Don't forget to buy enough fruit and vegies!

Don’t forget to buy enough fruit and vegies!

Hmmm, what's in the freezer?

Hmmm, what’s in the freezer?

So now it’s time to consider the math used to pilot the ship.  Think about degrees in a compass bearing and the need to do some rapid mental math as you’re steering a 231-foot ship through some very tight spaces.  Quick—take a course of 340o, now look ahead and get ready to change your bearing to 28oRainier’s draft (how deep it sits in the water) is around 16’.  Will the channel be deep enough?  What if you’re traveling in a supertanker, one that might be over 400’ in diameter and have a draft up to 80’ deep?  If your ship is that big, you need to scale up on your mental math calculations as you’re searching out appropriate harbors and routes! What about tying up the ship when we’re in harbor? Did you remember to learn something about vectors before you stopped taking math classes?

When we were at port in Cold Bay, the winds were expected to increase in strength and to shift so that they would be coming out of the west.  Since the pier was oriented perpendicular to the predicted wind direction, our Chief Bo’ sun, Jim Kruger had to do some mental calculations of the angles needed to secure the ship to the pier and keep it from bouncing too much.  He doubled and even tripled some of the lines, taking into account how the winds might move the ship as well as the strength of each line.  It takes some stout lines to hold this ship; each 300 ft. line is 1” in diameter and has a tensile (breaking) strength of 164,000 lbs.    Vector angles were equally important as we pulled away from the pier in a 50-knot wind.  Just pulling up our gangway with a crane required some careful mental calculations of where to place lines to steady it as it rose through the air and was lifted onboard. If your mental math and visualization skills were wrong, you might be rewarded with a wildly swinging piece of metal.

Double (and triple) up the lines holding the ship to the pier.  Make sure the angles are right.

Double (and triple) up the lines holding the ship to the pier. Make sure the angles are right.

Hang tight to the gangway as it swings onboard.  Make sure you're holding it at the correct angle to compensate for the wind.

Hang tight to the gangway as it swings onboard. Make sure you’re holding it at the correct angle to compensate for the wind.

Strong winds--this digital anemometer records current wind speed in knots as well as the highest gust.

Strong winds–this digital anemometer records current wind speed in knots as well as the highest gust.

How about all that hydrographic data collection; there’s plenty of opportunity there for some pretty extreme mathematical calculations.  You might even wish you had taken a class in calculus—or a few classes!  But there are also plenty of times that some basic number sense and arithmetic come in mighty handy.  As I sat on the pier watching the tide gauge, one of the tasks I had to do was to calculate the average between high and low water marks on the tide staff.  Not such hard math, but it’s a good skill to be able to do averages in your head while your hands are getting cold and the wind is howling.  The tide gauge calculations were referenced to Coordinated Universal Time (UTC). This has been our world standard since 1972, and is referenced to the 0o meridian at Greenwich, England.  It is precisely measured using an atomic clock.  You might also hear it referred to as Zulu Time.  Even airplanes use this time designation.  This way, there is no ambiguity about whether you are in daylight savings or standard time, or your time zone.  When measuring tides or collecting information about water chemistry using the CTD, or calculating the launch’s daily gyrations, it is important to reference everything to the same time standard.  Since the Rainier is on RST (Rainier Standard Time), the calculation gets even more important because we are in the Alaska time zone, but have set our clocks back one more hour to give us more daylight working hours).

What's your time zone?  GMT stands for Greenwich Mean Time.  It is also the UTC time standard we use.

What’s your time zone? GMT stands for Greenwich Mean Time. It is also the UTC time standard we use.

Just in case your brain hasn’t been addled by all this talk of mathematics, there’s one more concept that might come in handy here on the high seas—a sine wave.  Huh?  Sine waves are a mathematical curve describing smooth repetitive oscillations.  Like…tides, sonar pulses, sunrise/sunset observations, or the music booming out of your iPod.

Tide charts show a predictable, repeatable sine wave pattern.

Tide charts show a predictable, repeatable sine wave pattern.

I even use math to calculate how long I should run on the elliptical trainer down in the ship’s exercise space.  If I set the resistance to 8, and use a cross training setting, it takes around 35 minutes to ‘run’ the equivalent of one slice of cake!

Here's some of the exercise equipment on the ship.

Here’s some of the exercise equipment on the ship.

35 minutes or one slice of pie--whichever comes first!

35 minutes or one slice of pie–whichever comes first!

Just in case you haven’t gotten the message—math is good.  Number sense is critical—even if you want to run off to sea!

Personal Log

IT’S A FIELD TRIP!!

The entire Cold Bay School fits into this truck!

The entire Cold Bay School fits into this truck!

I love a field trip.  There’s nothing like loading up in the bus and taking off in search of the great unknown.  While we were parked at the Cold Bay pier, we had a visit from the Cold Bay School.  The 8 students, plus their teacher and a classroom aide, came to check out the Rainier.  CO Rick Brennan gave them a tour, starting at the bridge, and ending with lunch in the wardroom.  Along the way, they learned about ships and ship life, NOAA, and the science of hydrography. Lunch was a real hit, since the kids all bring their own lunches to school.  Who wouldn’t like halibut tacos with all the fixings from the galley, or a peanut butter and jelly sandwich handmade by Commander Rick Brennan with a fresh cookie for dessert?

Cold Bay students check out some of the ship's BIG tools.

Cold Bay students check out some of the ship’s BIG tools.

I tagged along on the tour to talk with some of the kids and their teacher and to compare notes about schools.  While I always think of my school as small, with only 150 students, the school in Cold Bay is really small.  There are 8 students and they represent grades 1 through 7.  While the school is small, each student uses an iPad to access a wide variety of educational resources. It’s even better when that technology-based learning is supplemented by some hands-on field trip-based learning.  This was their second field trip of the week; they had spent a day with a wildlife biologist helping install a motion-sensitive camera in the Izembek Wildlife Refuge (http://www.fws.gov/alaska/nwr/izembek/index.htm).

Future hydrographers head back to school.

Future hydrographers head back to school.

SAFETY FIRST

Where I live, in Colorado, we occasionally get snow days, when the roads are too dangerous to transport children to school.  Here at sea, we don’t worry too much about snow, but wind can create hazardous working conditions.  Yesterday we had what I would call a ‘Wind Day’; none of the survey launches went out.  The winds were gusting up to 50 knots, and were fairly steady at 30 knots.  That’s windy.  The surface of the bay was a froth of water, waves, and whitecaps.  Even the Black-legged Kittiwakes were having trouble flying!

Whitecaps all across the bay.  Definitely NOT a day to survey the sea floor.

Whitecaps all across the bay. Definitely NOT a day to survey the sea floor.

Certainly not the sort of day where you want to send out teams of hydrographers in 28 foot long launches.  While safety is paramount, data quality also suffers in such ‘bouncy’ seas.  As the launch bounces from side to side or from front to back, the sonar sends its pings far afield.  It becomes difficult or impossible to drive straight, overlapping lines as you ‘mow the lawn’ through your polygon (Wait, there’s another math term!) , and turning the craft requires timing and skill as you move through the rolling seas.  As the Rainier nears the end of its time at sea and in Cold Bay, each day becomes critical to achieve its charting goals—but there’s plenty of work to do on board on a day like this.  

   

Susy Ellison, A Hydrographic Wonderland, September 13, 2013

NOAA Teacher at Sea
Susy Ellison
Aboard NOAA Ship Rainier
September 9-26, 2013

Mission:  Hydrographic Survey
Geographic Area: South Alaska Peninsula and Shumagin Islands
Date:  September 13, 2013

Weather:  current conditions from the bridge
You can also go to NOAA’s Shiptracker (http://shiptracker.noaa.gov/) to see where we are and what weather conditions we are experiencing
GPS Reading:  55o 15.037’ N  162o 38.025’ W
Temp: 10.44C
Wind Speed: 9.8 kts
Barometer: 1021.21 mb
Visibility:  foggy on shore

Science and Technology Log

Since leaving Kodiak 5 days ago, I have been immersed in a hydrographic wonderland.  Here’s what I’ve learned, summed up in two words (three, if you count the contraction); it’s complicated.  Think about it.  If I asked you to make a map of the surface of your desk you could, with a little bit of work and a meter stick, make a reasonably accurate representational diagram or map of that surface that would include the flat surface, as well as outlines of each item on the surface and their heights relative to that surface, as well as their location relative to each other on a horizontal plane.  You might want to get fancy and add notes about the type of surface (is it wood, metal, or some sort of plastic), any small irregularities in that surface (are there some holes or deep scratches—how big and how deep?), and information about the types of objects on the desk top (are they soft and squishy, do they change location?).  Now, visualize making this same map if your desktop was underwater and you were unable to actually see it.   Not only that, the depth of the water over your desktop can change 2 times each day.  If that isn’t complicated enough, visualize that the top of the water column over your desk is in constant motion.  OK, not only all those variables, but pretend you are transformed into a very teeny person in a small, floating object on that uncertain water over the top of your desk trying to figure out how to ‘see’ that desktop that you can’t actually see with your own eyes?  Welcome to the world of the hydrographer; the challenge of mapping the seafloor without actually touching it.  It is, indeed, a complex meld of science, technology, engineering, and math (STEM, in educational parlance), as well as a bit of magic (in my mind).

How do you know what's down there?

How do you know what’s down there?

Challenge number one—how do you measure something you can’t see or touch with your own hands?  Long ago, sailors solved that obstacle by using a lead line; literally, a line with a lead weight attached to the end.  They would drop the weighted line over the side of their ship to measure the depth.  These soundings would be repeated to get enough data to provide a view of the bottom.  This information was added to their maps along with estimates of the horizontal aspects (shoreline features and distance from the shoreline) to create reasonably good charts that kept them off most of the underwater obstacles. A simple solution to a complex problem.  No electricity required, no advanced degrees in computer science needed, no calculus-based physics necessary.  Fast- forward to 2013 and the world of complex calculations made possible by a variety of computer-based algorithmic calculations (i.e. some darn fancy computing power that does the math for you). The NOAA Ship Rainier’s hydrographers use sound as their lead line, traveling in small boats known as launches that are equipped with multibeam sonar that send a series of sound ‘pings’ to the ocean floor and measures the time between sending and receiving the ping back after its trip to the bottom.  Sounds simple enough, doesn’t it?  If it were all that simple I wouldn’t be typing this in a room on the Rainier filled with 20 computer monitors, 10 hard drives, and all sorts of other humming and whirring electronic devices.  Not only that, each launch is equipped with its own impressive array of computer hardware.

One of the launches is lowered from the ship.

One of the launches is lowered from the ship.

So far on our survey days 2 launches have been sent out to cover identified transects.  Their onboard crew includes a coxswain (boat driver), as well as 2-3 survey technicians and assistants. Each launch is assigned a polygon to survey for the day.

EVERY PING YOU TAKE…

Once they arrive at their assigned area, it’s time to ‘mow the lawn’—traverse back and forth systematically collecting data from one edge of your assigned polygon to the other until the entire area has been surveyed. Just in case you haven’t realized it yet, although that sounds pretty straightforward, it isn’t. Is the area shallow or deep?  Depth affects how much area each traverse can cover; the sonar spreads out as it goes downward sending it’s little pings scampering to the ocean floor. Visualize an inverted ‘V’ of pings racing away from the sonar towards the sea floor. If it’s deep, the pings travel further before being bounced back upwards.  This means that the width of each row the sonar cuts as it “mows the lawn” is wider in deeper water, and narrower in shallow.  Shallower areas require more passes with the launch, since each pass covers a more limited area than it might if the water were deeper.  As the launch motors back and forth ‘mowing the lawn’, the sonar  signature is recorded and displayed on monitors in the cabin area and in front of the driver.  Ideally, each lap overlaps the previous one by 25-50%, so that good coverage is ensured.  This requires a steady hand and expert driving skills as you motor along either over or parallel to ocean swells.  All you video gamers out there, take note–add boat driving to the repertoire of skills you might need if you want to find a job that incorporates video gaming with science!

sonar screen

One of the monitors displays the sonar. The green line is the seafloor. This image shows that the deeper the sea, the wider the swath that is covered with each pass of the launch.

Calvin Burch uses a computer monitor to guide him as he drives the launch.  It's an art to 'mow' in straight lines while anticipating every roll and bounce of the coean's surface.

Calvin Burch uses a computer monitor to guide him as he drives the launch. It’s an art to ‘mow’ in straight lines while anticipating every roll and bounce of the ocean’s surface.

Here’s a small list of some of the variables that need to be considered when using sonar to calculate depth; the chemistry of the water column through which you are measuring, the variability of the water column’s depth at specific times of day, the general depth (is it shallow or deep), and the movement of the measuring device itself.  So many variables!!

Starla Robinson and Randy Shingeldecker monitor our progress on the launch's computer monitors.

Starla Robinson and Randy Shingledecker set up the program that will enable them to monitor our progress

HOW FAST DOES SOUND TRAVEL?

When you’re basing your charts on how sound travels through the water column, you need to look at the specific characteristics of that water.  In a ‘perfect world’, sound travels at 1500m/second through water.  In our real world, that speed is affected by salinity (the concentration of salts), temperature, and depth (water pressure).  The survey crew uses a CTD meter to measure Conductivity, Temperature, and Depth.  The CTD meter is deployed multiple times during the day to obtain data on these parameters.  It is attached to a line on the rear of the launch, dropped into the water just below the surface for 2 minutes, and then lowered to near the ocean floor to collect data.  After retrieval, it’s hooked to the computer on the launch to download the data that was collected.  That data is stored in its own file to use when the data is reviewed in the evening back on board the Rainier.  This is one of the variables that will be applied to the sonar data file—how fast was the sound moving through the water?  Without this information to provide a baseline the sonar data would not be accurate.

ctd deploy 1

Randy Shingledecker gets ready to send the CTD over the side. It’s clipped into a stout line and a reel for lowering it.

ctd retrieval 1

The CTD is lowered to just above the seafloor to collect data on Conductivity, Temperature, and Depth. This data will be applied to our sonar data to obtain an accurate sound speed for this area.


 

 

 

ROCKING AND ROLLING…

When you’re out on the ocean in a boat, the most obvious variable is the instability of the surface, itself.  This is called ‘attitude’.  Attitude includes changes to the boat’s orientation fore and aft (pitch), side-to-side (roll), and up and down (heave) as it is gently, and not-so-gently rocked by ocean swells and waves.  This means that the sonar is not always where you think it is in relation to the seafloor.  This is like trying to accurately measure the height of something while you, the measurer, are on a surface that is constantly moving in 3 different directions. Good luck.  Luckily for this crew of hydrographers, each boat is equipped with a little yellow box whose technical name is the IMU (inertial measurement unit) that I call the heave-o-meter, as we bob up and down on this might ocean.  This little box contains 3 gyroscopic sensors that record all those forward and backward pitches, sideways rolls, as well as the bobbing up and down motions that the boat does while the sonar is pinging away.  This information is recorded in the launch’s computer system and is applied to the sonar data during analysis back at the Rainier.

This yellow box is the IMU.  It's internal gyros capture information about the boat's pitch, roll, and heave.

This yellow box is the IMU. It’s internal gyros capture information about the boat’s pitch, roll, and heave.

TIME AND TIDE…

Now that you’ve gotten your launch to the correct polygon (using GPS data to pinpoint your location), taken CTD readings to create a sound transmission profile for your transect area, and started up the heave-o-meter to account for rocking and rolling on the high seas, it’s time to start collecting data.  Wait—there’s still another variable to think about, one that changes twice daily and affects the height of the water column.  You also have to factor in changes in the depth of the water due to tidal changes. (for an in-depth look at how tides work, check out this link: http://oceanservice.noaa.gov/education/kits/tides/tides01_intro.html).  At high tide, there’s a greater likelihood that subsurface obstacles will be covered sufficiently.  At low tide, however, it’s pretty important to know where the shallow spots and rocks might lurk.  NOAA’s hydrographers are charting ocean depths referenced to mean lower low water, so that mariners can avoid those low-water dangers.

You might be asking yourself, who keeps track of all that tide data and, not only that, how do we know what the tide highs and lows will be in an area where there are no other tide gauges?   NOAA has tide gauges along many coastal areas.  You can go online to http://tidesandcurrents.noaa.gov/and find out predicted tide heights and times for any of these locations.  While we are working here in Cold Bay, we are using a tide gauge in nearby King Cove, as well as a tide gauge that the Rainier’s crew installed earlier this summer.  More data is better.

Here's the tide chart from the King Cove tide gauge.

Here’s the tide chart from the King Cove tide gauge.

What do you do if you’re surveying in an area that doesn’t have existing tide gauges?  In that case, you have to make your own gauge that is referenced to a non-moving point of known elevation (like a rock).  For a detailed description of how these gauges are set, check out NOAA TAS blogs from some of the teachers who preceded me on the Rainier. On Wednesday, I helped dismantle a tide gauge on Bird Island in the Shumagin Islands that had been set up earlier this season (check out TAS Avery Martin’s July 12th posting), but had ceased to report reliable data.  Our mission on Wednesday was to find out if the station had merely stopped reporting data or if it had stopped collecting data entirely. 

Setting off in a skiff to check on the Bird Island tide gauge.

Setting off in a skiff to check on the Bird Island tide gauge.

When we arrived at Bird Island we found out exactly why the gauge had stopped sending data—its battery bank had fallen from one rocky ledge to another, ripping apart the connections and breaking one of the plastic battery boxes in the process.  That took a lot of force—perhaps a wave or some crazy gust of wind tore the 3 batteries from their mooring.  Since each battery weighs over 25lbs, that means that something moved over 75lbs of batteries.  Ideally, the station uses solar panels to keep the batteries charged.  The batteries power up the station so that data can be sent to a satellite. Data is also stored on site in a data logger, but without power that data logger won’t work.

This is the data logger for the tide gauge.  It is housed in a watertight box and was retrieved for downloading on the ship.

This is the data logger for the tide gauge. It is housed in a watertight box and was retrieved for downloading on the ship.

We retrieved all the equipment and will be able to download whatever data had been recorded before the system broke. The automated tide gauge is, basically, a narrow diameter air-filled tube that is underwater and set at a fixed depth with a narrow opening pointed downward to the seafloor. The pressure required to balance the air in the tube is equal to the pressure of the water column directly above the opening.  The tide gauge measures this pressure and converts it to depth.  Pressure/depth changes are recorded every six minutes—or ten times each hour. As it turns out, the damaged battery bank was only one of the problems with this station.  Problem number two was discovered by the dive team that retrieved the underwater portion of the gauge; the hose had been severed in two locations. In this case, something had caused the tube to break, so it was no longer connected to the data logger.  That must have been some storm!

ENC Carrier inspects the battery bank that inow s on a rock ledge 2 feet below where it had been placed!

ENS Carrier inspects the battery bank that rests on a rock ledge 2 feet below where it had been placed weeks ago!

The waterproof battery boxes were broken in the tumble.

The waterproof battery boxes were broken in the tumble.

The solar panels that charged the batteries were intact, still tied into bolts in the rocks.

The solar panels that charged the batteries were intact, still tied into bolts in the rocks.

The dive crew gets ready to jump in

The dive crew gets ready to jump in

Brrr, it's chilly work diving in arctic waters.  The divers are investigating the gauge and removing the damaged hose

Brrr, it’s chilly work diving in arctic waters. The divers are investigating the gauge and removing the damaged hose

While there, we set to work checking on benchmarks that had been set earlier in the season.  We used a transit and survey rods (oversized rulers) to measure the relative heights of a series of benchmarks to ensure accuracy. There are 5 benchmarks along the beach.  Each one was surveyed as a reference to the primary benchmark nearest the gauging station.  Multiple measurements help ensure greater accuracy.

I am holding the survey rod on top of a benchmark.

I am holding the survey rod on top of a benchmark.

 

I used a level to make sure the rod was plumb--perpendicular to the benchmark.  No easy feat with a strong wind blowing!

I used a level to make sure the rod was plumb–perpendicular to the benchmark. No easy feat with a strong wind blowing!

We also were tasked with checking the primary benchmark’s horizontal location.  While this had been carefully measured when it was set back in July, it’s important to make sure that it hasn’t moved.  It might seem a crazy concept to think that a benchmark cemented into a seemingly immovable piece of rock could move, but we are in a region that experiences seismic events on an almost daily basis.  (You can check out seismic activity at http://www.aeic.alaska.edu/) NOAA Corps Officer ENS Bill Carrier set up a GPS station at the benchmark to collect 4 hour’s data on its position, a process called HORCON (horizontal control).  Unfortunately, the winds were in charge of how much data we were able to collect that day, and blew down the station after only 3 hours! [image of station down]  Sometimes the best laid plans …..

A gust of wind blew the recording station down.

A gust of wind blew the recording station down.

 

DATA, DATA, and MORE DATA

While data collection is important, it’s what you do with the data that really gets complicated.  Data management is essential when working with so many files and so many variables. Before each launch returns to the Rainier, the day’s data is saved onto a portable hard drive.  Immediately after being hauled back up onto the ship, the data is handed off to the ‘Night Processing Team’ and hustled off to the Plotting Room (computer HQ) to be uploaded into a computer.  This is where the magic happens and an advanced degree in computer science or GIS (geographic information systems) can come in handy.  I have neither of those qualifications, but I know how to read a screen, click a mouse, and follow directions.  So, on Friday evening I was ushered into the ranks of ‘night processor’.

When each launch returns to the ship, their day's data is saved onto a hard drive.  This drive is transported to the plotting room to download onto the computer.

When each launch returns to the ship, their day’s data is saved onto a hard drive. This drive is transported to the plotting room to download onto the computer.

First, data is downloaded into the main computer.  Each launch’s files are called raw data files and are recorded in the launch’s acquisition logs.  Once the data is on the computer, it is important to set up what I call a ‘file tree’; the series of files that increase in specificity.  This is analogous to having an accurate list of what files live within each drawer and section of your file cabinet. These files are color-coded according to the operations manual protocols to minimize the chance of misfiling or the data.  They are definitely more organized than the files on my laptop—I might change my lackadaisical filing ways after this trip!

Once the data are placed in their folders, the fun begins.  Remember, you have files for multiple variables;  sonar, CTD casts, the IMU Heave-o-meter, and tide data.  Not only that, you have, with any luck, performed multiple casts of your CTD meter to obtain accurate data about the conditions affecting sound wave transmission within your polygon.  Now you get to do something I have never done before (and use a vocabulary word I never knew existed and one that I might try to spell in a future Scrabble game); you concatenate your CTD data.  Basically, you put the data from all your CTD casts together into one, neat little file.  Luckily, the computer program that is used does this for you.  Next, you direct the program to add all the variables to your sonar files; the concatenated CTD data, tide data, and IMU data.

 

Survey Tech Brandy Geiger and ENS Wall begin to upload the data and organize it into files.

Survey Tech Brandy Geiger and NOAA Corpsman ENS Wall begin to upload the data and organize it into files.

Assuming all goes well and you have merged all your files, it’s time to ‘clean’ your data and review it to make sure there are no obvious holes or holidays in the data that was collected.  Holidays can occur if the launch was bouncing too much from side to side during data collection and show up as a blank spot in the data because the sonar was out of the water and not pinging off the bottom.  You can identify these holidays during the data collection process [holiday signature], but sometimes there are smaller holidays that show up once the data is merged and on your computer screen.  There can also be miscellaneous errant pings caused by debris in the water column.  Cleaning involves systematically searching each line of your surveyed polygon to identify and delete those ‘bad’ pings.  Kind of like photoshopping away the parts of a digital image that you don’t want in the final image.  You work methodically in a grid pattern from left to right and top to bottom to ensure that you are covering the whole file.  It sounds easy, but to a non-PC person such as myself all that right click, left click, center click stuff was a bit boggling.  The program is amazingly complex and, rumor has it, a little bit ‘buggy’ at times.

Multiple screens, multiple tasks.  I am learning the art of 'cleaning' the data--getting rid of extraneous pings.

Multiple screens, multiple tasks. I am learning the art of ‘cleaning’ the data–getting rid of extraneous pings.


After all this, guess what?!  You still don’t have a chart.  It takes almost 2 years to go from data collection to chart publication.  There’s endless amounts of data compilation, reports to be written, and quality control analysis to be completed before the final report and charts are issued.

Personal Log

So far I have spent two nights on the ship ‘in transit’, moving between ports. The other nights have been spent anchored offshore. While the first night at sea was a little bouncy, the second was, in my opinion, the wildest roller coaster ride I have ever taken.  Imagine being pulled to the top of a high roller coaster, and released to fly down to the bottom while you are lying flat in your bed.  That’s what it felt like as we motored from the Shumagin Islands to an anchorage in Cold Bay.  An endless series of up, up, ups, followed by a wild ride down, down, down. Luckily all the drawers and doors have latches that keep them from flying open—although I had a jacket hanging on a hook that seemed to hit the latch on one closet door and actually knock it open—after this happened a couple of times I gave up and put the coat on the floor and firmly shut the door.  My bathroom trash can ended up in the shower stall.  At one point I heard a loud thump in the dark—and realized my survival suit in its orange bag had fallen from the top bunk to the floor—glad I wasn’t in its way! It was time to just hang on and try not to roll out of bed.

If your chair isn't tied down, put tennis balls over the wheels to keep it from rolling!

If your chair isn’t tied down, put tennis balls over the wheels to keep it from rolling!

tiedown1

Strap the printer tightly to a table!

tiedown2

Don’t forget to secure the trashcans!

We finally stopped rocking and rolling around 3 in the morning.  I thought maybe I was just a bit sensitive to the rocking motion, but was comforted to find out the everyone agreed that it had been a wild night.  In fact, one of the potential ‘hazards’ for our work on Thursday was ‘lack of sleep’.

FOO Meghan Mcgovern goes over the Plan of the Day (POD).  Today's identified hazards included 'Lack of Sleep'.

FOO LT Meghan McGovern goes over the Plan of the Day (POD). Today’s identified hazards included ‘Lack of Sleep’.

 

After almost a week aboard the Rainier I have been impressed with the teamwork, precision, and overall efficiency which overlays all operations. This crew can get a launch loaded, lowered, and underway in less time than it sometimes takes me to record my morning attendance at school!  This is no simple feat (the boat, not the attendance!).  It reminds me of a buzzing beehive filled with activity and focused on a single task; data collection. Each day begins on the fantail (the rear of the boat) at 0800 with the FOO (Field Operations Officer) reviewing the POD (Plan of the Day) and a summary of the day’s goals, work assignments, weather, and potential hazards, prior to sending out the survey crews.

The Boatswain (bo’sun) directs the next part of this tightly choreographed activity, as the launches are lowered by their davits (small cranes), while lines and hooks are handled with an eye to safety and efficiency.  Within 5 minutes the two launches have been lowered, loaded with crew and supplies, and are on the water, buzzing away from the hive like bees to perform their daily waggle dance as they move back and forth collecting hydrographic data.

At 1630 they return to the hive, filled with the sweet nectar of hydrographic data.  Launches are lifted back onto the ship and the data is whisked off to the computer room for downloading. 5 Minutes later a survey team debrief is held to review work accomplished that day and any problems that may have come up so that plans can be made for the next day’s work.  This crew is organized!!

The NOAA Ship Rainier

The NOAA Ship Rainier