Tag: Weather

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Michele Brustolon, July 10, 2010

NOAA Teacher at Sea
Michele Brustolon
Onboard NOAA Oscar Dyson
June 28 – July, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Eastern Bering Sea (Dutch Harbor)
Date: July 10, 2010

Weather Data from the Bridge

Time: 1400
Latitude: 59.12N
Longitude: 174.02W
Cloud Cover: 5/8
Wind: 17 knots
Air Temperature: 8.00 C/ 460 F
Water Temperature: 7.00 C/ 450 F
Barometric Pressure: 1006.9 mb

Science and Technology Log

Weather, weather everywhere!
Aside from weather helping you decide what to wear for the day, weather is critical on board a research vessel. Each hour the bridge collects the same data that is then input into the AMVER Sea system and sent to NOAA Weather. Some of the information included is: time, latitude, longitude, cloud cover, air and water temperatures, wind, barometric pressure, visibility, and swell height. This helps determine our exact location (check out shiptracker.noaa.gov) as well as the weather at sea and also weather inland. It is not uncommon for marine weather systems to move inland. This information also helps us understand long term climate changes, precipitation, and ocean currents.

Exactly where are we?
The latitude and longitude help determine the position of the ship and the time is recorded to understand how the ship is moving and in what direction. This allows the scientists to follow the transects to conduct their research. If I told you at 1500 hours (3pm) our mark was 58.00N and 171.48W, you would be able to pinpoint our location on a map. Our latitude so far on this trip (July 7th) has been in the range of 56.12N-58.69N depending on the transect that we are following and the longitudes’ range is between 170.01W-171.48W.

Transect lines for Leg II onboard Oscar Dyson

It’s cloudy again?
It tends to be quite cloudy and foggy here in the Bering Sea and cloud cover is measured in eighths of the sky. For example, on July 6th the cloud cover at 1500 hours was 7/8 which means that 87.5% of the sky was filled with clouds. Cloud type and location can help predict the type of weather. The majority of our days have been 8/8 or 100% cloud cover with stratus clouds and lots of moisture in the air.

Stratus Clouds

This is definitely not the heat wave they are getting back home!
This brings us to air temperature and wind. The temperature is always taken on the windward side of the ship because this is the side of the ship in the stream of air fresh from the sea that has not been in contact with or passed over the ship. There are two types of thermometers in each case on the deck in front of the bridge. The dry bulb measures the air temperature and the wet bulb has a muslin wick which absorbs heat from the thermometer. The temperature difference between the two, called the depression of the wet bulb, can help determine what the percent humidity is by referring to the humidity chart. Wind can affect these readings which is why there are thermometers on either side of the bridge. The wind direction is logged as the same direction from which the sea waves are coming. Average temperature through July 7th for Leg II has been 5.680C/420F with winds averaging 10.29 knots.

The weather mentioned has been the trend for Leg II; however, this could be changing by the end of the week…stay tuned!

Wet and dry bulb thermometers

Hold on tight!

It’s July 10 and we are still waiting for the big seas to hit us. (not that I am complaining about calm weather!) The swells have gotten larger and the wind definitely picked up yesterday. The strongest wind recorded yesterday was 26 knots while on my shift. There is still a chance for NW sustained winds up to 25 knots and 10 foot seas before the weekend is up. Part of the reason for calmer seas yesterday was that we were so far north and the low pressure system was to the south of us. It was actually the farthest north I have ever been, and we will go even farther north before it is time to head back to Dutch Harbor.

Weather forecast

Personal Log

While we have had some quiet days, the fishing has been picking up. Unfortunately, the fish seem to be accessible more for the night crew than our shift. For example, we may fish once in a twelve hour shift, but the night crew may fish 2-3 times! We did have a couple of fishing mornings where there was enough time for a quick coffee and piece of toast and then on to the wet lab. Let me paint a picture for you… its 0430, the four of us (Abigail, Katie, Rebecca, and I) are keeping the beat to the tunes on the iPod of choice for the day in our full foul weather gear while we sort, sex, weigh, and find the lengths of pollock. It’s quite the jam session- all before breakfast! It may seem like a strange way to start the day, but it’s pretty cool!

Pollock on the sorting table
Processing Pollock: we record data about length, weight, stomachs, and otoliths.

Another benefit to having the day shift is that I was able to experience sunset as I looked west (off the port side of the ship) from my stateroom at 0330 and by the time we finished fishing at 0645, the sun was rising! Between 0400 and 0700 is one of the quieter times during my shift. It is a good time to get laundry done, regroup for the day, and one of the most peaceful places to go is the bridge. As you finish climbing the stairs you enter the darkness of the bridge; no fluorescent or incandescent lights staring you in the face. Even the headlamps worn and the covered monitors are red. I found myself closing my eyes and rocking as the boat swayed back and forth. Definitely a different atmosphere then being in the wet lab processing fish. This of course all changes after breakfast when more people are up for their shift. I find it amazing how many different environments there are on one ship throughout a day.

Sunset: 0400
Sunrise: 0645
The bridge at sunrise

Another new experience for me occurred by the time I made it to the Acoustics lab on Friday morning. The echo sounder was already in the water collecting data. The advantage of this single transducer is that it has the ability to be dropped closer to the fish (about 50m) to allow for more precise data. It still functions like the transducers that are on the centerboard of the ship: sending “pings” or sound waves and recording target strength. The transducers that do not interfere with the echo sounder continue to collect the same data but from farther away (around 80m), and then the two sets of data can be compared. There is also a small CTD that is attached to the unit. To make it even better, I was able to see the North Star and the moon while on the deck where the echo sounder comes on board!

The echo sounder

This might be too much excitement for some of you, but like I said before I need things to do. This brings me to the new challenge on the ship; Ensign Amber Payne spearheaded a “European Challenge of the Century.” It is a series of exercise challenges that include all members on board the Oscar Dyson. Now, this challenge continues throughout this season which ends in October, so the scientists (that’s me!) were randomly placed on teams to contribute while onboard. Even before the challenge, Abigail, Katie, Rebecca, and I have made a habit of heading to one of the two gyms to rip it up while blasting tunes. That’s right- two gyms on this ship! You can chose to run, bike, row, lift, and there are plenty of other options as well. Even though the gym has become part of my daily routine and running on a boat MUST burn more calories than on land, I don’t think it has been enough with Ray’s cooking. It’s like eating out at your favorite restaurant EVERY day!

Animals seen
Chrysaora melanaster
pollock (1-2 years)
fulmars
murres
puffin

Word of the day
guile: deceit

New Vocabulary
barometric pressure: the downward force that the atmosphere exerts per unit of a certain area.
swell height: measure of wind waves generated locally; vertical distance between trough and crest
muslin wick: plain woven cotton fabric
humidity: the amount of moisture in the air
gale force winds: strong winds between 28-47 knots
target strength: strength of the sound waves returning after reaching the fish

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Christine Hedge, September 14, 2009

NOAA Teacher at Sea
Christine Hedge
Onboard USCGC Healy
August 7 – September 16, 2009 

Mission: U.S.-Canada 2009 Arctic Seafloor Continental Shelf Survey
Location: Chukchi Sea, north of the arctic circle
Date: September 14, 2009

Dr. Hall standing by the hovercraft before it is inflated
Dr. Hall standing by the hovercraft before it is inflated

Weather Data from the Bridge 
Latitude: 720 46’N
Longitude: 1580 24’W
Temperature: 350F

Science and Technology Log 

Doing science in the Arctic is challenging.  The weather is difficult, the ice is ever changing, and the expense of operating an icebreaker, aircraft, or helicopter is quite high.  So, how else can people get out onto the ice to study the ocean and the geology of the seafloor? One interesting project uses a hovercraft (think air hockey), which skims over the ice on a cushion of air. Using a hovercraft to study the most inaccessible places in the Arctic is not a new idea. But, Dr. John K. Hall, a member of our science party has taken this idea and run with it.   John has a long history of polar exploration under his belt. Including 13.5 months floating around the Arctic on a 90 square kilometer, 60-meter thick ice sheet known as Fletcher’s Ice Island (T-3) during the 1960’s. His latest project has been to purchase and equip a hovercraft to go where icebreakers cannot (areas of VERY thick ice).

Norwegian students parked on the ice doing research. The white tent protects the scientists while they collect data through a drill hole in the ice.
Norwegian students parked on the ice doing research. The white tent protects the scientists while they collect data through a drill hole in the ice.

The hovercraft was completed in 2007.  She is called the R/H Sabvabaa, which is the Inupiaq word for “flows swiftly over it.”  This hovercraft was designed specifically for doing science in Arctic conditions. It is equipped with all the comforts of home and all the latest technology.  From this research platform scientists have access to echosounding and seismic equipment to study the sea floor.  They can also park the Sabvabaa easily on a floe, get out on the ice to drill, photograph, and collect samples from under the ice.  This small 40-foot vessel (it fits in a semi-truck container) has great potential as a way for scientists to collect data in heavy ice conditions.  For more information about the Sabvabaa check out this website.

Classroom on the Ice 

Could you imagine being one of the first people to ride the hovercraft over the pack ice?  Since 2008, 16 lucky Norwegian high-school students have had that honor.  A competition was held as part of the Norwegian International Polar Year (IPY) program.  This competition set out to find Norwegian students ages 14-18 who are interested in careers in polar geophysics. A pair of students and a pair of researchers worked from the Sabavaa for one-week intervals. During their time on the Sabvabaa, the winning students participated in geophysical, geological, and oceanographic studies on drifting ice. They also had 4 encounters with polar bears!  What a great opportunity for these students. If you are interested in the student blogs from these trips (which are written in Norwegian) do a Google search for Sabavaa and have Google translate them.

FOR MY STUDENTS: Remember, not all scientists work in labs wearing white lab coats!  Many researchers lead exciting and adventurous lives. 

Paul Henkart teaching Nikki Kuenzel and Christina Lacerda.
Paul Henkart teaching Nikki Kuenzel and Christina Lacerda.

Personal Log 

As an educator, one of the best parts of this expedition has been to watch the mentoring that goes on. The scientists and professors in the science party have decades of research experience to share. It is not unusual to find one of these veteran Arctic explorers sharing their expertise with graduate students from the University of New Hampshire. Not only do these “mentor scientists” have great technical expertise. They are also really good at explaining complex ideas in a very simple way.   This has been wonderful for me since my background is in biology – so geophysics has been a challenge. The graduate students on board are not only learning science from the masters – they are hearing great adventure stories about past polar adventures before we had helpful technologies such as GPS and multibeam echosounders. Everyone on the Healy is in “learning mode”.  The Coast Guard crew, teachers at sea, scientists, and students are constantly asking questions and sharing expertise.

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Patricia Donahue, August 22, 2008

NOAA Teacher at Sea
Patricia Donahue
Onboard NOAA Ship Rainier 
August 19-23, 2008

Mission: Hydrographic Survey of Bear Cove, AK
Geographical Area: Kachemak Bay, Alaska, 59.43.7 N, 151.02.9 W
Date: August 22, 2008

One of the Rainier’s small boats, also called a launch
One of the Rainier’s small boats, also called a launch

Science and Technology Log 

Much of today had to do with technology. The small boat I went out on, pictured to the right, was filled with computer equipment. Each day at the survey technology department meetings, I’ve listened but not entirely understood the reports of computer issues on the small boats.  This morning I witnessed one such incident. Something didn’t work. Fortunately, there was a work-around and the data collection proceeded smoothly.

I was reminded of the early 18th century efforts to determine longitude. The problem was so pressing that kings of various countries offered rewards for the development of a clock that could keep time at sea. In 1772, James Cook, for whom Cook Inlet in Alaska is named, sailed with the first marine chronometer. The chronometer was a clock that kept accurate time for the home port. On board Cook’s ship, Resolution, there was another clock that kept local time.

Sonar equipment is lowered into the water.
Sonar equipment is lowered into the water.

Since the Earth turns 15 degrees of longitude each hour, by using the difference between the two clocks, seamen would know how far east or west they had traveled. They already knew how to determine latitude with an instrument called a sextant so by using the marine chronometer they could actually plot their coordinates. Now, of course, we take GPS for granted. Many people even have GPS in their cars. These devices and the hand held ones I use with my students at school are accurate to within 4 to 10 meters. Well, the boat I was on today has DGPS, which is even better. It is accurate to within 5 centimeters! With this high-tech equipment, NOAA is able to take very accurate measurements and make very accurate maps.

This graph depicts the velocity of sound through water.
This graph depicts the velocity of sound through water.

The boat I was on today used multi-beam sonar to determine the depth of the ocean floor. This is similar in concept to the single beam in that ping return-times are used. The multi-beam uses a lot more pings, sometimes as many as 200 per second. In the picture above, the sonar equipment is being lowered into the ocean. I learned that salinity, temperature and depth (which is another way of saying pressure) determine the electrical conductivity and density of the water. These two factors then determine the sound velocity.  In the graph, depth is on the Y axis and velocity is on the X axis. Notice the bulge in the plotted line. This represents an area nearer the surface where glacial melt water and ocean water are mixing. The velocity of sound through this water is slower than deeper down where it’s mostly salt water.

This graph displays the pitch, roll, and heave of the boat.
This graph displays the pitch, roll, and heave of the boat.

Measurements of salinity, temperature, electrical conductivity, depth and density were taken 27 times today. This data will be used to adjust the sound velocity to get the most accurate picture of the ocean bottom. The movement of the boat also has an effect on the sonar equipment. NOAA is using the moving vessel profiler or MVP to eliminate the interference caused by the boat’s movement. A boat has a pitch, roll and heave. The computer screen to the left shows graphs of these three types of movement. What do you think was happening on the boat at about halfway across the graph? Remember, the boat is “mowing the lawn” as it collects data. Lastly, the tides also affect the data. Upon return to Rainier, the data is processed and also corrected for the effect of the tides.

TAS Donahue gets a chance to drive the launch.
TAS Donahue gets a chance to drive the launch.

Personal Log 

Several crewmembers have tried fishing from the boat and we’ve seen many small boats with fishermen aboard but no one has caught anything. Using the binoculars aboard the small boat today I watched someone land a fish. I think it was a halibut, which makes sense since we’re in Halibut Cove. The most exciting part of the day was driving the small boat. Data was not collected from a small piece of sea bottom so the boat had to make one last pass over it with the sonar equipment. I’ve driven many different vehicles, even a motorcycle, but a boat is different. I couldn’t make it stay straight!

The scariest thing that happened today didn’t happen to us at all. The United States Coast Guard broadcast a message all afternoon over the marine radio. The message would also start with “pan, pan, pan,” which is the appropriate way to begin a distress call. Most of us have heard of “may day” calls. Those are used when there is immediate danger. A “pan” call is more similar to a warning. A boat carrying two adults and one child had not returned as expected and was missing. The Coast Guard was asking all other boaters to keep an eye out for them. I hope they’ve been found and that everyone is okay.

Animals Seen Today 

A raft of otters, Common Murres, Marbled Murrelets, and Barrow’s Goldeneye

Vocabulary of the Day 

The coxswain is the person who drives the boat.

Challenge Yourself What is 5 cm in inches? What types of movements are pitch, roll and heave?

 

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Patricia Donahue, August 21, 2008

NOAA Teacher at Sea
Patricia Donahue
Onboard NOAA Ship Rainier 
August 19-23, 2008

Mission: Hydrographic Survey of Bear Cove, AK
Geographical Area: Kachemak Bay, Alaska, 59.43.7 N, 151.02.9 W
Date: August 21, 2008

Weather Data from the Bridge at 1000 hours 
Broken clouds (7/8)
Visibility 11 to 27 nautical miles
Winds calm
Seas 0-1 ft (light breeze) at 9.4˚C
Air pressure 1001.5 millibars and rising slightly
Dry Bulb 12.2˚C, Wet Bulb 11.1˚C
Cumulus clouds between 3000 and 5000 feet

The lines circled in red are the track that the boat follows back and forth in order scan the bottom of the sea. It’s a lot like mowing a lawn!
The track that the boat follows back and forth in order scan the bottom of the sea. It’s a lot like mowing a lawn!

Science and Technology Log 

We are anchored in Halibut Cove near a large lagoon too shallow even for the small boats to enter. The nearby mountains have attracted my attention. According to the chart for this area, the two seen off the bow are both 3600 feet high. They have some patches of snow on them. A taller mountain, 4200 feet high, is barely visible in the distance. Nearer the shore some cliffs show evidence of an interesting geological history. Once upon a time, marine sediments collected at the bottom of the sea. The layers built steadily one atop the other, creating organic and clastic sedimentary rocks. The rocks were uplifted to nearly vertical and have eroded. The lighter colored section appears to be limestone but it’s difficult to tell from afar. Due to intense tectonic activity in the area, some of the rock was heated and crushed, causing metamorphism. The section next to what I think is limestone looks to be either a metamorphosed limestone or a batholith. I’m hopeful that someone on board knows more geology than I do!

One of these scans shows a school of fish and the other shows a mound on the sea floor. Can you guess which is which? (Answer: the scan on the left is a mound on the sea floor and the scan on the right is a school of fish.)
One of these scans shows a school of fish and the other shows a mound on the sea floor. Can you guess which is which?

Today I went out on one of the small vessels conducting single beam sonar scanning to determine the depth and shape of the bay bottom. The boat moves across the surface of the sea in straight, parallel lines much like the ones made when cutting the grass with a lawn mower. The lines in the first picture are the rows that the boat “mows.” The sonar pings go down from the bottom of the boat at a rate of 100 per second! The equipment on board measures how much time passes until the ping returns from the bottom. The longer it takes for the sound signal to bounce back, the deeper the water is in that location. The boat also has another scanner similar to what fishermen use to find schools of fish. Look at these two photographs from the scanner. Which is a school of fish and which is a 27 foot high mound on the ocean floor? The depth of the water is in large numbers in the lower left. The numbers farthest to the right are the ocean temperatures. Why is the water colder where the bottom is deeper?

This is a sea otter feasting on a clam! The tiny white spec on its belly is the clam
This is a sea otter feasting on a clam! The tiny white spec on its belly is the clam

Personal Log 

The screen above with the “mowing the lawn” lines on it clearly shows an airplane making its way back and forth. Of course I had to ask, “Why an airplane icon”? I thought they’d tell me that it was for laughs but no, there is a good reason. The airplane icon’s nose keeps in sync with the GPS and the lines better than the ship icon! The surveyors find it easier to know their position.

Animals Seen Today 

  • Many sea otters – Look closely at the picture to the left. The otter in the picture is eating clam. A shell is balanced on its belly!
  • Schools of fish under the boat “seen” by the radar
  • Several types of birds too far away to identify

Vocabulary of the Day 

While inputting the weather this morning, I noticed several screens that we did not add data to and rather than skip them, I decided to see what they were about. They were about ice conditions that a ship might encounter and include in a weather report. Here are two new words I didn’t have for ice. A bergy bit is a large piece of floating glacier ice between 100 and 300 square meters in area and showing less than 5 meters but more than 1 meter above sea level. A growler is smaller than a bergy bit. It is larger than 20 square meters in area but less than 1 meter is above the sea surface. Growlers can be transparent, green, or even black in appearance. Since its summer in Alaska, I won’t be seeing any bergy bits or growlers! I also learned that the term iceberg has a precise definition. An iceberg is a piece of ice afloat or aground that shows more than 5 meters above the sea surface. They are described more specifically by their shape.

Challenge Yourself 

Kachemak Bay receives a lot of glacial melt water. Surveyors have a difficult time with the radar equipment when they encounter freshwater because the sound waves travel at a different speed through fresh water than they do through salt water. In which type of water, salt or fresh, does sound travel faster? Why?

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Patricia Donahue, August 20, 2008

NOAA Teacher at Sea
Patricia Donahue
Onboard NOAA Ship Rainier 
August 19-23, 2008

Mission: Hydrographic Survey of Bear Cove, AK
Geographical Area: Kachemak Bay, Alaska, 59.43.7 N, 151.02.9 W
Date: August 20, 2008

Weather Data – Glorious!

Science and Technology Log 

black bear comes to inspect what the land party is up to!
A black bear comes to inspect what the land party is up to!

WOW! That says it all. Today’s big excitement was supposed to be the leveling of the tidal gauge and the survey work in the cove. The bigger thrill – and scare – was the bear that approached to within 30 feet of me as I was standing over a benchmark with a leveling rod. Remembering the safety rules about bears, I stayed calm and alerted the others. Then I put down the pole and walked away slowly. Fortunately it was a young and smallish black bear who was easily scared off by the Commander throwing rocks. We were all on our guard the rest of the day. There were several benchmarks to check. Some of the climbing was perilous. All of the work had to be done at low tide. The survey data was collected and I look forward to seeing what’s done with it.

During the afternoon, another emergency drill took place and I was invited to watch. In the scenario, the bridge lost the ability to steer the ship. Control of the vessel had to be made from aft steering, below decks where the rudders protrude from the vessel. By using only a compass and steering orders given in degrees, the helmsman maneuvered the ship. There were no windows or other indicators of the ship’s position. To make matters worse, the scenario called for a loss of communications so a sound powered phone that uses only the energy from the speaker’s voice to operate had to be used instead.

A benchmark on the Alaskan coastline
A benchmark on the Alaskan coastline

By late afternoon the ship moved to its new anchorage a few miles from Homer. I was invited to watch the lowering of the anchor. The anchor weighs 3500 pounds and there are two of them. Each length of chain weighs 1200 pounds and there are a total of 12 lengths for each anchor. Today we used only 5 sections of chain and 1 anchor. Each section of chain is 90 feet (15 fathoms) long. The anchor is lowered while the ship is in reverse.

Personal Log 

My family and my students enjoy a game called geocaching. We’ve started by using hand held GPS devices to find benchmarks and eventually we’ll move on to finding caches and creating our own. I’ve only ever seen old benchmarks but today I saw brand new ones. One of the officers even showed me how they’re made. Benchmarks indicate the exact location and height above sea level of that particular place. The Chief Steward took me to see the food storage facilities. The freezer is enormous! The ship carries enough food to last for 6 months, although the fresh fruits and vegetables only last for one month. They have more food than CostCo!

Animals Seen Today 

Stellar’s Jay, Black Bear, and two species of Jelly Fish

Question of the Day 

How long is the anchor chain on the Rainier? Provide your answer in feet and fathoms. How much do the anchors and the chain weigh altogether? Why is the boat in reverse when the anchor is dropped?

Challenge Yourself 

Go to http://www.geocaching.com and type in your zip code. Identify a benchmark near your home. Find it and take a photograph!