Author: Tamil Maldonado

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Tamil Maldonado, July 27, 2005

NOAA Teacher at Sea
Tamil Maldonado
Onboard NOAA Ship Fairweather
July 18 – 28, 2005

Mission: Hydrographic Survey
Geographical Area: North Pacific
Date: July 27, 2005

Science and Technology Log

During the day I talked with the captain about boat stability.  Stability is defined as the ability of a vessel to return to its original condition or position after it has been disturbed by an outside force. Anyone who has been at sea and felt the vessel roll, for example, and then right itself (only to roll in the opposite direction and right itself again) has seen stability in action.

Outside forces include wind seas, adding/removing weight, and free surface.  The six Motions of a Vessel in waves are rolling, pitching, yawing, heaving, swaying, and surging. Rolling is the motion about the vessel’s longitudinal axis.  Pitching is the motion about the vessel’s transverse axis.  Yawing is the motion about the vessel’s vertical axis.  Heaving is the vertical bodily motion of the vessel (whole vessel moves up and down together). Swaying is lateral (side to side) bodily motion.  Surging is the longitudinal (fore and aft) bodily motion.  All or most of the motions can occur simultaneously and have their effect on the efficient operation of a vessel.  While the ship’s officer cannot completely control these motions, there is much that can be done to diminish or alleviate their effects.

Motions of the Vessel and Governing Stabilities include:  Roll- Transverse Stability, Pitch- Longitudinal Stability, Yaw- Directional Stability, Heave – Positional Motion Stability, Surge – Stability in motion Ahead or Astern, Sway – Lateral Motion Stability. The way a vessel rolls is a direct indication of her stability.

The condition of a vessel is determined almost solely by the location of two points: the Center of Gravity (G) and the Center of Buoyancy (B).  G is the point at which all vertically downward forces of the vessel can be considered to act.  In other words, the ship will behave as though all of its weight were acting downward through this point.  B is the point at which all the vertically upward forces of support (buoyancy) can be considered to act, or, the center of volume of the underwater portion of the vessel.  In other words, the ship will behave as if all of its support is acting up through this point. There are a lot of mathematical concepts and processes to compute stability.  Theory of Moments, Inclining formula, Trigonometry, Change in Mean Draft are also implied in vessel stability.

During the afternoon I worked on the computer, and I put all my pictures on the FAIRWEATHER’s computer network.

We also had the drills: 1) Men on Board, 2)  Abandon Ship, and 3) Fire and Emergency.

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Tamil Maldonado, July 26, 2005

NOAA Teacher at Sea
Tamil Maldonado
Onboard NOAA Ship Fairweather
July 18 – 28, 2005

Mission: Hydrographic/FOCI Survey
Geographical Area: North Pacific
Date: July 26, 2005

Science and Technology Log

We are underway in the Gulf of Alaska, Southeast of Sitkinak Island.  This is our last day of doing FOCI survey. We used the Bongo Tow and CTD throughout day.

At 5:00 p.m. we were done with survey and transiting to Dutch Harbor, AK

At night I interviewed Chief Scientist, Janet Duffy-Anderson, one more time.  We talked about how to know fish ages and how fast they are growing.  It is because of their rings— the number of rings a larvae has will give the days they are alive.  Also, you can know their age by how far apart those rings are, which gives you the information of how fast they are growing.

Furthermore we talked about atmospheric changes and how this is affecting the ecosystem.  The target of FOCI is to get biological as well as physical data on the changes in the ocean and how those changes interact with the biota.  They wanted to do this research in Alaska because you can see changes more rapidly at the poles of the planet. We have seen phenomena like El Nino, La Nina and others increasing in frequency and duration. The rate between phenomena is increasing—they are happening  more frequently for the last decade.

I will be able to get fisheries raw data in time series done by FOCI and will continue doing some research back home in this area.

At night we did an acoustic hydrographic survey, and by changing depth target we got different data, all related. Changing the depth target changes how deep the beams go through the water and come back.  We worked with Hips & Sips Computer Software.  This program also corrects in real time the error estimates for each contributing sensor.  These entries are necessary for the computation of the Total Propagated Error.  The Vessel Configuration File (VCF) contains information about the different sensors installed on the survey vessel and their relationship to each other.  The information in the file is applied to logged, converted data files, and when the final sounding positions are calculated, the data is merged.  The entries in the VCF are time tagged and multiple time tags can be defined for each sensor.  This allows the user to update sensor information during the course of a survey.  This may occur if a piece of equipment has been moved.

In order to define the new fields in the VCF it is essential to understand standard deviation. The standard deviation is a statistic that explains how tightly various examples are clustered around the mean in a set of data.  When the data is tightly bunched together the bell-shaped curve is steep and the standard deviation is small.  When the data is spread apart, the bell curve is relatively flat indicating a larger standard deviation.

The vessel information will be displayed in the Vessel Editor.  The sensor positions are represented by colored dots. The VCF can be updated if a sensor changes position, and a unique time stamp ensures that the correct offsets are applied to data recorded at a certain time.  Each time the sensor information is changed, the drop down list above the 3-D vessel model will be updated to include the new time stamps.  The data grid below the 3D vessel contains all the offset information for the vessel.

Tomorrow… we will talk about the stability of the ship, and how its is done (so we do not sink!).

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Tamil Maldonado, July 25, 2005

NOAA Teacher at Sea
Tamil Maldonado
Onboard NOAA Ship Fairweather
July 18 – 28, 2005

Mission: Hydrographic Survey
Geographical Area: North Pacific
Date: July 25, 2005

Personal Log

We sailed through Sitkalidok Strait, southeast of Aliulik, Kodiak Island.  I got up seasick at 1:30 a.m. and stayed awake till 4:30 in the morning.  I went back to sleep and after lunch I took a seasick pill to feel better.  It just made me sleepy.

In the afternoon I interviewed one of the student scientists, Dylan Righi.  He is a programmer and his work deals with wavelets using drifters to recollect data.  He also “cleans” the data, since there is always some noise to be corrected.  He graphs the path of different types of drifters into the water and does some numerical analysis.  He runs a FORTRAN code on a UNIX system parallel to a computer back in Seattle.  His data analyses are from the North East Pacific regions.  The resolution of the wavelets is approximately 9 km, 520 points.  Anyone interested on the code or data could get it from FOCI website.

Sick 1:30 a.m.gt Sleep Talked with a programmer scientist about wavelets

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Tamil Maldonado, July 24, 2005

NOAA Teacher at Sea
Tamil Maldonado
Onboard NOAA Ship Fairweather
July 18 – 28, 2005

Mission: Hydrographic Survey
Geographical Area: North Pacific
Date: July 24, 2005

Science and Technology Log

I started today on a night shift. I got up at 2:00 a.m. and worked with scientists that were doing a 24:00 – 12:00 (noon) shift. We used the bongo and tucker nets, plus the CTD to collect samples of water.  The CTD has 11 fiver-liter spaces that are opened electronically in different sea columns.  This gives a good idea of what is going on in terms of salinity, temperature, pressure, and food for fish throughout the ocean (vertically).  The other nets just take surveys as a hole or by only two regions of columns.

At 5:00 a.m. I stayed on the bridge and on watch till 7:00 a.m. and tried to make the boat steady. After breakfast I went to sleep.  After lunch I went to the engineering department and learned about engines, and how the boat actually works.  Some of the engines work with oil, some with seawater, and other ones with fresh water.  It was incredible for me to see all the machinery behind a boat’s work.  The engineer explained about the maintenance and equipment.  We also went to the refrigeration room to see how the system works with compression and condensation, how AC gets to our rooms, and how the boats use all the engines for energy, movement, and stability.

The sea weather today was awful—big waves coming in during afternoon and at night.  Many people got seasick today.

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Tamil Maldonado, July 23, 2005

NOAA Teacher at Sea
Tamil Maldonado
Onboard NOAA Ship Fairweather
July 18 – 28, 2005

Mission: Hydrographic Survey
Geographical Area: North Pacific
Date: July 23, 2005

Science and Technology Log

Today I interviewed the Electrical Technician about satellites on the ship, server computers, connections among rooms, computer labs, processes of e-mails, phone communications, and digital vs. analog communication.  He showed and explained all equipment they have in the computer rooms,  how systems talk to each other, how the e-mail codes and compresses data, and how they are stored in lines and by priorities.  He also showed me how they keep information in different places in the boat in case there is a fire in regions where they have the servers.  Moreover, he explained the different satellites and which ones are being used all the time for navigation.  It was really interesting to see all the systems working together.

I studied more about sonars and how they actually work undersea.  I read about the sonar setup, vessel operation, data analysis, and how noise is reduced on these sonars by the speed of the ship. For example, in a SeaBat 8160 sonar the best vessel speed while doing the survey is at 10 knots. There are exciting papers of Noise Analysis explaining the type of sonars they use.

At the end of the day I did some laundry and saved pictures on disks.