NOAA Teacher at Sea: Caroline Singler Ship: USCGC Healy
Mission: Extended Continental Shelf Survey Geographical area of cruise: Canada Basin in Arctic Ocean Date of Post: 23 August 2010
A Great Day for Flying – 22 August 2010
Location and Weather Data from the Bridge
Date: 22 August 2010 Time of Day: 2200 (10:00 p.m.) local time; 05:00 UTC Latitude: 78º31.9’N Longitude: 149º21.3’W Ship Speed: 4.2 knots Heading: 63.8º (northeast) Air Temperature: 3.98ºC/38.10ºF Barometric Pressure: 1024.6 mb Humidity: 67.5% Winds: 7.4 knots NE Wind Chill: -0.4ºC/31.2ºF Sea Temperature: -1.3ºC Salinity: 27.64 PSU Water Depth: 3829.9 m
Date: 23 August 2010 Time of Day: 2310 (11:10 p.m.) local time; 06:10 UTC Latitude: 78º31.9’N Longitude: 149º21.3’W Ship Speed: 4.9 knots Heading: 4.3º (NNE) Air Temperature: -1.74ºC/28.87ºF Barometric Pressure: 1026.8 mb Humidity: 93.7% Winds: 8.4 knots NW Wind Chill: -8.05ºC/17.5ºF Sea Temperature: -1.4ºC Salinity: 27.25 PSU Water Depth: 3773.9 m
Sunday wasn’t an ordinary day right from the start. As always, I checked the Almanac data on the ship tracker map when I woke up in the morning, and I noticed that there were no sunrise and sunset times listed, only local noon – 8/22 22:06Z, which is 3:06 p.m. here – and local midnight – 8/23 10:05Z, or 3:05 a.m. here. Sometime on Saturday night, we ventured into latitudes that are far enough north to still receive 24 hours of daylight at this time of year. The weather was perfect – high pressure, clear skies, a few high wispy cirrus clouds, light wind, and temperature just above freezing. The sea ice coverage was between 6 and 8 tenths – more than we had seen recently. Where previously there was open water between ice floes, now there was grease ice – a thin icy surface that shimmered in the morning sun and formed intricate patterns when pushed aside by larger pieces broken by Healy.
Just when it seemed that a day couldn’t get much better, my pager went off, which always catches me by surprise. Chief Scientist Brian Edwards informed me that PolarTREC teacher Bill Schmoker and I would be visiting the Louis after lunch along with two Healycrew members. Suddenly the teachers at sea became “Teachers Aloft”, a catchy phrase courtesy of USGS scientist Helen Gibbons.
Helicopter operations (“flight ops”) on Healy are serious business. A lot of work goes on behind the scenes to ensure the safe transfer of personnel between the two ships. I thought I would be more nervous than I was, but there wasn’t much time to be nervous. I just did what I was told and before I knew it we were on our way. Here are some photos taken before the flight. (Photos taken by USGS scientist Helen Gibbons unless otherwise noted.)
Suiting up in a Mustang floatation suit:
Canadian Ice Services Specialist Erin Clark briefs us about safety issues before our flight on the Canadian Coast Guard helicopter.
Walli Rainey of Natural Resources Canada gave us a tour of the living and working spaces on Louis, which are set up differently from Healy’s – Healy feels more like a working vessel with a distinct military style; Louis is designed a bit more for comfort, with drop ceilings covering the pipes, ducts and wires that are exposed on Healy and curtains on the windows, many of which are large square windows not portholes. While visiting the bridge, I noticed that we were surrounded by ice, which puzzled me because Healy was breaking ice for Louis, but pressure on the ice had caused it to move back into the track cleared by Healy. Healycame around to starboard to try to help free Louis from the ice, giving us an opportunity for a good look at and photo opportunity of our “home” ship.
Eventually, the captain determined that Louis could not get free without pulling the seismic gear. Less than an hour later, we were on our way back to Healy with a great new experience to share.
NOAA Teacher at Sea: Caroline Singler Ship: USCGC Healy
Mission: Extended Continental Shelf Survey Geographical area of cruise: Arctic Ocean Date of Post: 20 August 2010
Out in the Canada Basin — 16-20 August 2010
NOAA Teacher at Sea: Caroline Singler Ship: USCGC Healy Mission: Extended Continental Shelf Survey Geographical area of cruise: Arctic Ocean Date of Post: 20 August 2010Location and Weather Data from the Bridge Date: 16 August 2010
Time of Day: 2240 (10:40 p.m. local time); 05:40 UTC Latitude: 71º 34.5’ N
Longitude: 156º 42.2’ W Ship Speed: 16.5 knots Heading: 19.2º (NE) Air Temperature: 8.2ºC/46.7ºF Barometric Pressure: 1006.3 mb Humidity: 92.6% Winds: 16.6 knots NE
Wind Chill: 2.5ºC/36.7ºF Sea Temperature: 6.3ºC Salinity: 30.96 PSU Water Depth:124.7 m (on continental shelf near Barrow AK)Date: 17 August 2010 Time of Day: 2120 (9:20 p.m. local time); 04:20 UTC Latitude: 74º 6.1’ N Longitude: 150º 26.4’ W Ship Speed: 4.2 knots Heading: 14.8º (NNE) Air Temperature: 1.5ºC/34.7ºF Barometric Pressure: 1003.7 mb Humidity: 91.5% Winds: 22.9 knots E
Wind Chill: -5.7ºC /21.7ºF Sea Temperature: -0.7ºC Salinity: 25.00 PSU Water Depth:3729.1 mDate: 18 August 2010
Time of Day: 2320 (11:20 p.m. local time); 06:20 UTC Latitude: 75º 25.1’ N Longitude: 153º 16.9’ W Ship Speed: 4.7 knots Heading: 311.1º (NW) Air Temperature: 0.45ºC/32.8ºF Barometric Pressure: 1010.1 mb Humidity: 95.3% Winds: 20.7 knots SE
Wind Chill: -5.8ºC /21.5ºF Sea Temperature: -1.0ºC Salinity: 24.87 PSU Water Depth:3848.4 mDate: 19 August 2010
Time of Day: 2230 (10:30 p.m. local time); 05:30 UTC Latitude: 76º 11.8’ N Longitude: 155º 14.3’ W Ship Speed: 4.4 knots Heading: 83.1º (NE) Air Temperature: -0.47ºC/31.1ºF Barometric Pressure: 1013.9 mb Humidity: 100% Winds: 7 knots SE Sea Temperature: -0.76ºC
Salinity: 24.7 PSU Water Depth:~2100 mDate: 20 August 2010
Time of Day: 2200 (10:00 p.m. local time); 05:00 UTC Latitude: 76º 28.4’ N
Longitude: 149º 5.3’ W Ship Speed: 4.9 knots Heading: 80.1º (NE) Air Temperature: -0.23ºC/31.6ºF Barometric Pressure: 1020.9 mb Humidity: 98.2% Winds: 5.7 knots WNW Wind Chill: -0.23ºC /31.6ºF Sea Temperature: -1.2ºC Salinity: 25.99 PSU Water Depth:3824.4 mScience and Technology Log
I have fallen behind on my writing this week, and I am trying to get back on track. I have a couple of logs in progress, but none are finished yet. So I thought I would give a quick update on where we are and what we are doing.
We started the week with a quick trip to Barrow, Alaska to pick up a crew member and some equipment for Louis. It was a beautiful day. Healycannot dock in Barrow, so we waited a couple of miles offshore while a small boat went in to shore.
We had a great view of the coastline. The air smelled different that close to land; there were lots of birds flying around, and some people evenspotted whales. Late Monday we started our trip back into the Canada Basin and met up with Louisearly Tuesday morning.
We are now fully involved in the two-ship partnership with the Louis. We have been traveling together for four days. Most of the time, Healyleads Louis, though once yesterday the two ships switched positions, and Louis broke ice for Healywhile they made repairs to their seismic equipment. My personal theme for the mission is “If we’re moving, we’re mapping” which means that the multibeam and subbottom profiler are always collecting data. Sometimes in ice we don’t get perfect data, but all data are useful data, and each line we follow unveils a little more information about the Arctic seafloor. Sometimes we cross areas that were mapped on previous trips by Healy or other vessels, filling in gaps in the bathymetry and giving Louis the opportunity to collect deeper subsurface data. My favorite times are when we cross areas that have never been mapped before.Most of the time, we have been out on the abyssal plain of the Canada Basin. The abyssal plain is FLAT – flatter, I am told, than a pool table. Yesterday we crossed the eastern side of a feature called the Northwind Ridge which separates the Canada abyssal plain from the Chukchi plateau and abyssal plain. It was a nice change to see some different depths on the multibeam. Different depths show up as different colors on the screen display – yellows, greens and light blues instead of just the deep blue and purple that represent depths over 3000 meters. As a watch stander, there is more to watch when we are crossing an area changing depths, and we have to make frequent adjustments of the depth limits for the instruments. Sometimes in the lab at night, I look at the display screen and forget that what I see on the bathymetric map is the seafloor, not what is out my window. I look at the camera that shows the water in front of and behind the ship, and I see flat water or ice, but underneath, there are ridges, slopes, and plains. It is incredible that we can use sound to remove the cover of the water and see what lies beneath.
I still find it surprising when I go out on one of the aft decks and see another ship behind us. I wonder how it would look to someone flying over us – way out in the ocean, no other boats around, but there are two ships following the same course about a mile apart. It takes a lot of coordination for two ships to work together like this. The chief scientists and captains consult frequently about the planned course. When I am on watch, I enjoy listening to the chatter between the bridges of the two ships, sharing information about ice conditions, checking speeds, confirming how well the track cleared by Healy is staying clear for Louis. That is not as easy as it might sound. The ice is drifting, and Healy’s crew must take that into account and determine where the ice might be when Louis reaches it.
I am fascinated not only by the sea and ice but also by the constantly changing Arctic sky. Every day, the sky is a new canvas for interesting cloud formations, sun shining through fog, and the sometimes subtle and sometimes spectacular colors of Arctic sunsets, which for a while (when we were in the southern part of the basin) coincided with the end of my nightly watch stander shift. Now that we are north of 75º, the sun sets between 1 and 2 a.m. local time and rises again around 4 a.m., so it is usually still quite bright when I leave the computer lab. Perhaps one night before we head south, I will stay up all night and get a sense of how dark it really gets between sunset and sunrise – my impression is that it is not fully dark – there always seems to be at least some light coming through the porthole when I wake up during the night. Here are some of my favorite sky-shots from the last week.
Sometimes when I’m in the Science conference room, I like to look at the map of “Bottom Relief of the Arctic Ocean”. The other night, I noticed a picture in the picture. What do you see?FYI…
I got an email from a colleague (thanks, Mark) who asked me how far from land we were when we saw the polar bear that I photographed on August 9th. The map below shows where we were relative to the coastline of Alaska. We were stopped at the station labeled “001” at the time, which is approximately 172 nautical miles (319 kilometers) north of the town of Gordon, Alaska. (The dotted red line connects the two points.) Gordon is just west of the U.S./Canada border. As of today, that is still the only polar bear that I have seen. There have been at least six sightings from Healy and several more from Louis.
NOAA Teacher at Sea: Caroline Singler Ship: USCGS Healy
Mission: Extended Continental Shelf Survey Geographical area of cruise: Arctic Ocean north of Alaska in the Canada Basin Date of Post: 16 August 2010
Follow the Leader – 13 – 15 August 2010
Location and Weather Data from the Bridge Date: 13 August 2010 Time of Day: 2100 (9:00 p.m.) local time; 04:00 UTC Latitude: 73º0’N
Longitude: 145º3’W Ship Speed: 3.9 knots
Heading: 1.8º (north) Air Temperature: 2.0ºC/35ºF Barometric Pressure: 1018.9 millibars (mb) Humidity: 100% Winds: 3-5 Knots SW Sea Temperature: -0.4ºC Salinity: 25.37 PSU Water Depth:~3600 m
Date: 14 August 2010
Time of Day: 2105 (9:05 p.m.)
local time; 04:05 UTC Latitude: 73º36.4’N Longitude: 146º19.21’W Ship Speed: 4.7 knots Heading: 223º (southwest) Air Temperature: 2.15ºC/35.88ºF Barometric Pressure: 1022.3 mb Humidity: 92.1% Winds: 12.2 knots SE Wind Chill: -3.1ºC/26.5ºF Sea Temperature: -0.7 ºC Salinity: 24.84 PSU Water Depth: 3708.6 m
Date: 15 August 2010
Time of Day: 1500 (3:00 p.m.)
local time; 22:00 UTC Latitude: 72º56.4’N
Longitude: 150º9.0’W Ship speed: 11.8 knots
Heading: 220º (southwest) Air Temperature: 5.6ºC/42.2ºF Barometric Pressure: 1015.6 mb
Humidity: 98.1% Winds: 17.7 knots E
Wind Chill: 1.7ºC/35.1ºF Sea Temperature: 3.9ºC
Salinity: 24.5 PSU Water Depth:3691.1 mScience and Technology Log
The Extended Continental Shelf Project is a multi-year effort between the United States and Canada. The two countries share knowledge, resources, and information to allow greater coverage of the region and more cost effective achievement of the mission objectives. For this mission, the USCGC Healy is working in tandem with the Canadian Coast Guard ice breaker Louis S. St. Laurent, called Louis(pronounced “Louie”) for short. Healy is responsible for collecting bathymetric data and shallow subsurface imaging while Louis performs deeper subsurface imaging with her air-gun array. The instrumentation on Louis is towed behind the ship and requires a clear path through the ice; therefore, Healy’s primary responsibility when the ships are in ice is to lead and break ice for Louis. Healy opens a path and Louis follows, typically about one to two miles behind depending on ice and visibility conditions. It was foggy for most of the day on Friday as we led the way north along the first track line. The only way I knew that Louis was behind us was by watching the ship tracking chart and listening to occasional radio chatter between the two boats as the crews communicated about ice conditions. Skies cleared as we moved farther north and deeper into the ice on Saturday. Near midday, the fog lifted and there was Louis, first emerging like a ghostly image out of the fog and then, as we made the turn onto a new transect line, she was in full view. By Sunday afternoon we were heading south in open water, so Healy moved away fromLouis to conduct other business while our ice breaking services were not needed.
While multibeam sonar allows us to “see the bottom”, subbottom profiling uses a different sound-producing system to see what is under the bottom. Geologists use the subbottom data both from Healy andLouis to estimate sediment thickness and make inferences about sediment types and structures beneath the seafloor. It makes me think of Superman’s x-ray vision! Like multibeam sonar, subbottom profilers are echosounding devices. They are active sonar systems – sound signals are transmitted and received by the instrument.
Healy’s profiler is a “chirp” system mounted inside the bottom of the ship’s hull – so called because it sounds like a bird chirping, a sound that one hears in the background throughout the ship. It releases high frequency pulses of acoustic energy that travel through the water column and (in theory) hit the seafloor and penetrate into subsurface materials to depths of tens of meters. Signals are reflected at the seafloor and at interfaces between different subsurface layers within the seafloor. The reflection of acoustic energy depends on the “acoustic impedance” of the material encountered. Acoustic impedance is related to the density of the material and the velocity of sound in that medium. Different materials have different acoustic impedance and therefore different reflectivity. The concept is similar to that of albedo when one considers the reflection of solar energy from different surfaces. A smooth, light-colored surface like a field of snow reflects a high percentage of incoming solar rays and therefore has a high albedo– hence the glare that hurts your eyes on a sunny day. Dark-colored surfaces reflect much lower percentages of incident light and therefore have low albedo. (They also absorb more energy which is why they get hotter on a sunny day.)
With subbottom profiling, sands typically reflect sound differently than mud, and layers or other structures in the subsurface result in different signal strengths returning to the receivers on the ship. The picture on the right shows an image of the raw chirp data displayed on the computer screen at the watch stander station. It does not show a lot in this state, but after processing the data will provide important information about the subsurface in the Arctic Ocean.
Subbottom surveying on Louis is performed with a multi-channel air gun system that is towed behind the ship. Three air guns, powered by air compressors on the ship’s deck, provide the acoustic energy source. A streamer with an array of 16 hydrophones trails behind the air guns; the hydrophones receive the return signals reflected by the seafloor and subsurface sediments. In open water, the air guns are attached to a float and hang about three to five meters below the surface, at a distance of about 100 meters behind the ship. In ice, the air guns are attached to a metal sled (depressor) that hangs below the sea surface (and hence the ice) to a depth of about 10 meters and at a distance of about 10 meters behind the ship. When fired, the air guns simultaneously emit large air bubbles into the water column. As the bubbles collapse, an acoustic pulse is produced that moves through the water. It is similar to what happens in the atmosphere when air rapidly expands and contracts as a lightning bolt passes through, creating the sound we know as thunder. The air guns generate sound at a lower frequency than the chirp system; sound at these lower frequencies penetrates deeper into the subsurface but produces lower resolution than the higher frequency chirp system. Such air gun systems can provide images to depths of several kilometers below the seafloor.
Saturdays are “Field Days” on Healy. No, we did not all get into boats and take a trip away from the ship or get out onto the ice. Field Day is a fancy way of saying that it is time for cleanup and inspection of common areas and personal berthing areas. All personnel on board are responsible for trash removal and cleaning of staterooms, restrooms and common living and working spaces. Anyone who is not on duty pitches in to clean the Science lounge and labs – vacuuming, sweeping, washing floors and generally putting things in order. The “trash vans” are open twice a week; everyone brings trash and recycling to two large blue bins on the port side of the 02 deck (the same deck as the science staterooms). Coast Guard volunteers work the trash vans. Healy will be at sea for another long mission after this one, so efficient trash removal and storage is critical. Healy personnel are dedicated to recycling and have an award winning recycling program on board – no small feat when it is necessary to haul it all around for months at sea. Think about that when you are tempted to complain about separating recyclables from trash at home or at school.
Since everything was neat and tidy, I decided it was a good time to show you my living space on Healy. Science staterooms are set up for three occupants, but on this trip we have two people per room. I share a room with Sarah Ashworth, a marine mammal observer; she is currently on Louis, so for now I have my own room. The room is more spacious than I expected on a ship, similar in size to a lot of college dorm rooms.
Space is used very efficiently. There are bunk beds; Sarah has more experience at sea than I, so she has the top bunk or “rack”.
Each person has a good sized locker for clothes and since there are only two of us, we each have a desk and filing cabinet, so there is plenty of storage space – more than we need for our personal belongings.
There’s nothing like a room with a view, even if they left the tape on the window the last time they painted the ship.
Each room has its own sink, and shares a bathroom with the adjoining room. Okay, they call it a “head” on a ship; don’t ask me why! The bathroom is small, but one does not linger when taking a “sea shower”, and there is always plenty of hot water. In case you ever wondered what a marine toilet looked like, here it is.
We headed towards Barrow on Sunday to pick up a crew member and some supplies for the Louis. There was a steady wind from the east for most of the afternoon, and the boat was rolling a little, but I was more prepared for it this time than I was the first time it happened, but I still stumble when I walk down the hall.
We have had beautiful views of ice, sea, and sky for the last few days.
NOAA Teacher at Sea: Caroline Singler Ship: USCGC Healy
Mission: Extended Continental Shelf Survey
Geographical area of cruise: Arctic Ocean
Date of Post: 8 August 2010
Polar Bear, Polar Bear! – 9 August 2010
Yes, folks, they are out here. There were a couple of sightings on Sunday 8 August, but I missed them both. However, Monday 9 August 2010 was the day that I saw my first polar bear in the Arctic. The last time I saw a polar bear was in the St. Louis Zoo, and it looked about as unhappy to be in the heat and humidity as I was. This time was a lot different.
I received a page while working in a lab on one of the lower decks. Before I turned off my pager, Bill came running down to get his camera and told me there was a polar bear off the port side of the ship. We could just barely see a spot on the distant horizon, slightly less white than the surrounding ice. I went up to the Bridge to get a better view, and most of the science team was there. I didn’t have to ask where it was; I just followed the line of everyone’s binoculars and cameras. Once I had a sense of what to look for and where to look, it became easier to spot, and it obliged us by moving closer to the ship. We were holding position at the time for a water sampling event, so we got a good long view as the bear ambled along. It was like watching a nature movie. It stopped every once in a while to sniff the air, and it walked along, stepping or jumping across melt ponds on the ice. We watched for at least a half hour before it moved out of site.Here are some of my best shots.
I hope those images help cool you off for a minute or two!