Jacquelyn Hams: 3 December 2011

NOAA Teacher at Sea
Jackie Hams
Aboard R/V Roger Revelle
November 6 — December 10, 2011

Mission: Project DYNAMO
Geographical area of cruise: Leg 3, Eastern Indian Ocean

Date: December 3, 2011

Weather Data from the R/V Revelle Meteorological Stations

Time: 0930
Wind Direction: 232.10
Wind Speed (m/s): 3.4
Air Temperature (C): 27.7
Relative Humidity: 77%
Dew Point: (C): 23.7
Precipitation (mm): 42.2

PAR (Photosynthetically Active Radiation (microeinsteins): 1942.5

Long Wave Radiation (w/m2): 409.3
Short Wave Radiation (w/m2): 373.1

Surface Water Temperature (C): 28.70
Sound Velocity: 1541.5
Salinity (ppm): 33.7
Fluorometer (micrograms/l): 0.3
Dissolved Oxygen (mg/l): 2.4
Water Depth (m): 4422

Wave Data from WAMOS Xband radar

Wave Height (m) 0.5
Wave Period (s): 7.4
Wavelength (m): 86
Wave Direction: 1140

Science and Technology Log

Surface Fluxes Group

The Surface Fluxes group consists of James Edson, University of Connecticut, Ludovic Bariteau, University of Colorado Cooperative Institute for Research in Environmental Sciences (CIRES), and June Marion, Oregon State University. This group measures the amount of radiation and heat into and out of the ocean and was covered in the November 12, 2011 blog posting.

The purpose of this posting is to highlight the work of Ludovic Bariteau who is measuring the carbon dioxide flux between the atmosphere and ocean. For redundancy and testing, the carbon dioxide in the atmosphere is measured with several infrared instruments pictured below. Two of the instruments are in the pilot stage and were developed for this research cruise. The equipment used for measuring carbon dioxide in seawater is done in collaboration with Wade McGillis from Lamont-Doherty-Earth Observatory (LDEO). Ludovic plans to refine the instrumentation based on the pilot test. The carbon dioxide data will be correlated with surface flux data to present a complete picture of ocean atmosphere fluxes.

Photograph of flux instruments.
Photograph of flux instruments on the mast. The instruments measuring air CO2 are indicated by the black arrows. Image credit: James Edson.
Ludovic Bariteau in front of instrument to measure carbon dioxide fluxes.
Ludovic Bariteau in front of the specialized instrument to measure carbon dioxide fluxes between the ocean and atmosphere.
Closeup of carbon dioxide flux instrument.
The above photograph is a close-up of the apparatus used to measure the carbon dioxide content in the ocean water.
Ludovic Bariteau pointing to CO2 measurement device.
Photograph of Ludovic Bariteau pointing to one of the air CO2 measurement devices in the pilot stage.

        

Data printout of Carbon dioxide values of air and water measured from instrumentation aboard the Revelle provided courtesy of Ludovic Bariteau
Data printout of Carbon dioxide values of air and water measured from instrumentation aboard the Revelle provided courtesy of Ludovic Bariteau

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What about the MJO?

Previous postings described the work being done by the 7 science groups and the instrumentation being used to measure the various characteristics of the ocean-atmosphere interaction that may be part of the active phase of the MJO. Readers of this blog may be asking the same question that some of my students are now asking, “Did you experience the MJO?”

Data collected to date by the science groups suggests that we experienced an active MJO phase. Although It will take years to analyze and correlate the data collected from the various organizations involved in Project DYNAMO, the Revelle experienced high winds, colder surface water surface temperatures, and the intermittent storms separated by quiescent periods that are believed to accompany the active phase of the MJO. Based on initial data this active phase may have occurred between the approximate dates of Nov. 24 through Dec.2.

Wyrtki Jet Current

Before discussing the effects of the MJO on Indian Ocean circulation, it is useful to provide a brief background on the currents in the Indian Ocean which are more complicated than those in the Atlantic and Pacific Oceans in several ways:

  • Indian Ocean currents are poorly defined
  • They are influenced by the presence of the Eurasian continent
  • They are more variable than the Atlantic or Pacific Ocean currents. Some Indian Ocean currents vary with the seasons. For example, on the top diagram below, notice there are two unnamed gyres located in the northern hemisphere west and east of India.

Diagram of Indian Ocean Currents

The Revelle left station on December 2, and began north south transects across the equator to delineate the extent and the speed of the Wyrtki Jet Current. The Wyrtki Jet is a narrow jet-like surface current that flows eastward during the transition periods between the Northeast and Southwest Monsoon currents and is believed to accompany the active phase of the MJO.

A summary of the monsoon system in the Indian Ocean taken from the pdf version of Regional Oceanography: An Introduction by Tomczak and Godfrey. The Wyrtki Jet may be the Equatorial Jet identified on the below diagram.

Wyrtki jet speeds of 150 cm/s eastward at the surface were identified during the cruise.  In addition a current flowing westward was identified at a depth of 100 m. The purpose of the transects is to delineate the lateral and vertical extents of these currents.  The currents are measured using four Acoustic Doppler Current Profiler (ADCPs) located in the hull of the ship (these are Doppler sonars, analogous to Doppler radar and lidar measurements discussed in previous blogs).

Personal Log

I worked the winch for the last drop of Chameleon on Leg 3 of Project DYNAMO aboard the R/V Revelle.  I must say that I am proud of my work as a “Winch Winder”.  In the past 5 weeks, I experienced a range of emotions regarding the winch.  I initially felt fearful of working solo on such a valuable instrument. Once I began working solo, I was still intimidated because the winds and currents are so variable at the equator. Intimidation was finally replaced by competence after operating the instrument in 40 knot winds without slamming it into the ship! Aurelie Moulin was kind enough to shoot this video of me just before Chameleon was pulled out of the water on the last drop.

I would like to share my interview with Jude Irza, Ordinary Seaman aboard the R/V Revelle who provides extremely thoughtful advice and insight regarding career choices and preparation that may be helpful not only for students unsure of their future, but for those who may desire a career change at any stage in life.

Photograph of Jude Irza

Question: What made you decide on a career in this field?

 That question is straight forward enough but my answer is a little bit convoluted.  I never woke up one day and decided that I wanted to become a Merchant Marine and work on Oceanographic Ships.  In fact, I have been fortunate to have had two careers before this one:  Naval Officer and Finance Manager.  Here’s how I embarked on my first two careers.

 First, I attended college on a Naval Reserve Officers’ Training Corps Scholarship.  After college, I went to Flight School in Pensacola, Florida, and flew as a navigator in the United States Navy.  While in the Navy, I decided to expand my horizons and earn a Masters in Business Administration. While completing my MBA, I decided that a career in finance would be challenging and rewarding.  So I resigned my commission and I worked at a large telecom company in San Diego.  Later, I had the opportunity to join a telecom start-up and later a consulting company.   Although I enjoyed working in finance for fifteen years, I was ready to do something exciting and different.  I had always thought working as an Officer in the Merchant Marine would be fun. Expecting to be too old for this career, I was surprised and pleased when my research uncovered a new program where I could go to sea and work towards a Third Mate License through a two-year program offered by the Pacific Maritime Institute (PMI) in Seattle, Washington.  So, approximately two years ago, I joined the program and was partnered with the Scripps Institute of Oceanography.  I joined the R/V Revelle as an Ordinary Seaman.  Already, this is my fourth trip on the R/V Revelle and I am close to finishing PMI’s program.  I hope to take my Coast Guard License exams next summer and have my 1600 ton 3rd Mate License shortly thereafter.

 Question:  What are the positives and negatives of this line of work?

 The exact nature of the work depends on what billet or position one is filling and to an extent that determines the positives and negatives.  For example, an Ordinary Seaman like me spends most of the time cleaning, removing rust and painting.  Work is performed both inside and outside of the ship.  Mates, however, are Merchant Marine Officers, and spend most of their time standing watch, on the bridge of the ship.  Most, if not all, merchant mariners would agree that being able to travel and see the world are positives in this line of work.  The biggest negative is separation from family members for months at a time.  Typically, at Scripps, we are out to sea for eight months out of twelve.  Moreover, especially at the lower level positions, the work can be arduous and sometimes monotonous.

 Question:  What advice would you give students who are unsure of their career goals?

 I would give students five pieces of advice:

1. Get Information and Prerequisites – Get on the internet and research the careers in which you might be interested.  Learn about what qualifications and prerequisites are necessary for each career.  Try to find a person who is in that career and ask them good questions.  Be realistic, but also look for unconventional pathways.

 2. Inventory your Skills and Abilities – Try to determine what you enjoy doing and what you are good at.  Try and see what careers other people chose that have your talents and abilities.

 3. Get Real-World Experience – Try and experience careers directly without investing too much time and energy by taking a part-time, internship or volunteer position.  You’ll learn an enormous amount by working alongside other people.

 4.  Change your Career if you find that it is not Right for You – Some people, including myself, are not suited to only one career.  Don’t be afraid to try something new if you no longer find enjoyment in your current line of work.  But be financially responsible and try to not incur too much debt especially in your younger years.  You want to keep your options open and debt can limit options.

 5.  You are Never Too Old to Start Again – I am forty-five years old, but feel energized doing something new.  I don’t know if I will be in this career ten years from now, but I am certainly enjoying it now.

Jacquelyn Hams: 25 November 2011

NOAA Teacher at Sea
Jackie Hams
Aboard R/V Roger Revelle
November 6 — December 10, 2011

Mission: Project DYNAMO
Geographical area of cruise: Leg 3, Eastern Indian Ocean

Date: November 25, 2011

Weather Data from the R/V Revelle Meteorological Stations

Time: 0830
Wind Direction: 2340
Wind Speed (m/s): 9.6
Air Temperature (C): 25.5
Relative Humidity: 90.6%
Dew Point: (C): 24.3
Precipitation (mm): 41.3

Long Wave Radiation (w/m2): 442.5
Short Wave Radiation (w/m2): 114.6

Surface Water Temperature (C): 29.60
Sound Velocity: 1544.9
Salinity (ppm): 35.3
Fluorometer (micrograms/l): 0.3
Dissolved Oxygen (mg/l): 2.5
Water Depth (m): 4637

Wave Data from WAMOS Xband radar

Wave Height (m) 2.1
Wave Period (s): 8.9
Wavelength (m): 123
Wave Direction: 2780

Science and Technology Log

NASA TOGA C-Band Doppler Radar Group

The TOGA (Tropical Ocean Global Atmosphere) Radar Group consists of Michael Watson, NASA Contractor from Computer Science Corporation, Goddard Space Flight Center, Wallops Flight Facility, Wallops Island, Virginia; Elizabeth Thompson, Colorado State University; and Owen Shieh of the University of Hawaii.

The following paragraphs provide a brief description of TOGA C-Band Doppler Radar.

Radar is an acronym for radio detection and ranging. Radar was developed just before World War II for military use but now serves a variety of purposes including weather forecasting. Radar is an electronic device which transmits an electromagnetic signal, receives back an echo from the target and determines various characteristics of the target from the received signal. Doppler radar adds the capability of measuring direction and speed of a target by measuring the Doppler Effect, or the component of the wind going either toward or away from the radar.

  • Doppler radar is divided into different categories or bands, according to the wavelength of the radar.  Some common Doppler bands are:
  •  S-band radars operate on a wavelength of 8-15 cm and are useful for far range weather observation.
  •  C-band radars operate on a wavelength of 4-8 cm and are best suited for short-range weather observation.
  •  X-band radars operate on a wavelength of 2.5-4 cm and are useful for detecting tiny precipitation particles

The NASA TOGA C-Band radar has a range of 300 km. In addition to the TOGA C-band radar, the ship has both S and X band radar. These three systems allow large and small-scale forecasting capabilities.

When not deployed on field campaigns, TOGA radar resides at Goddard Space Flight Center, Wallops Flight Facility, Wallops Island, Virginia, where it gathers meteorological data and supports launches.

The large dome in the center houses the NASA Doppler C-Band radar antennae. Image credit: Jacquelyn Hams
The large dome in the center houses the NASA Doppler C-Band radar antennae. Image credit: Jacquelyn Hams

During Leg 3 of Project DYNAMO, TOGA radar scans are performed in the following intervals:

Automated high-resolution scans for a 150 km radius every 10 minutes

  • Automated high-resolution scans for a 300 km radius at the top and bottom of the hour (every 59 and 29 minutes)
  • Vertical cross sections at 9,19,39 and 49 minutes past the hour.

 Below are examples of radar scan images of a single storm cell and rainfall provided courtesy of Owen Shieh.

The TOGA Radar image on the left is a horizontal image looking down on the rain.  The ship is in the center. North is straight up toward the top of the image. The radar range is 150 km. The arrow indicates a single storm cell that is located 40 km from the ship. Towards the east (right side of the diagram) are large areas of light rain, indicated by white arrows.  Radar image on the right is a vertical cross section through the storm cell (indicated by the black arrow). The top of the storm extends up to 5 km and contains moderate rain indicated by the yellow color.
The TOGA Radar image on the left is a horizontal image looking down on the rain. The ship is in the center. North is straight up toward the top of the image. The radar range is 150 km. The arrow indicates a single storm cell that is located 40 km from the ship. Towards the east (right side of the diagram) are large areas of light rain, indicated by white arrows. Radar image on the right is a vertical cross-section through the storm cell (indicated by the black arrow). The top of the storm extends up to 5 km and contains moderate rain indicated by the yellow color.
TOGA Radar image on the left is the same as above, except taken 10 minutes later.  Notice that the storm cell (indicated by the black arrow) is closer to the ship, approximately 37 km away.
TOGA Radar image on the left is the same as above, except taken 10 minutes later. Notice that the storm cell (indicated by the black arrow) is closer to the ship, approximately 37 km away.
The TOGA radar image above is taken from a range of 300 km.  These images are taken every 30 minutes.  There are four areas of light to moderate rain surrounding the ship (indicated by white arrows).  Notice the scale of the storm cell (indicated by black arrow) looks considerably smaller. The large scale TOGA Radar image allows a wider view of the aerial distribution of rain.
The TOGA radar image above is taken from a range of 300 km. These images are taken every 30 minutes. There are four areas of light to moderate rain surrounding the ship (indicated by white arrows). Notice the scale of the storm cell (indicated by black arrow) looks considerably smaller. The large-scale TOGA Radar image allows a wider view of the aerial distribution of rain.

Personal Log

The day after Thanksgiving, the Ocean Mixing Group decided to pull the T Chain out of the water after discovering a couple of damaged cables. The Chief Scientist ultimately decided to move the ship to another location on the other side of the buoy. It was extremely windy that day and the team was trying to perform this task in hard hats which constantly blew off in the wind. I am sure we looked extremely comical to those who were watching. In addition, we had to juggle large pieces of foam used to protect the T Chain which promptly blew away. There were at least seven of us and I thought we probably looked like a scene from a Marx Brothers movie.

We are experiencing squalls on almost a daily basis that are separated by quiet calm periods and occasional sunshine. Weather data indicates that we may be in the active phase of the MJO. I managed to get some interesting sunset photographs with the cloud formations.

These photographs were taken at sunset on the Indian Ocean between squalls. Image credits: Jacquelyn Hams
This photograph was taken at sunset on the Indian Ocean between squalls. Image credits: Jacquelyn Hams
This photograph was taken at sunset on the Indian Ocean between squalls. Image credits: Jacquelyn Hams

My students want to know how I am adapting to the lack of privacy. This is not my first time on a ship and I own a sailboat so being at sea is not an uncommon experience for me. However, being at sea this long with so much to accomplish in a short time has caused the lack of privacy to become a big issue for me. In addition to covering the 7 science groups for this blog, I am teaching the last 5 weeks of my classes via distance education and posting assignments for my students based on data obtained on this cruise.

There are little things on the ship that make the lack of privacy more tolerable. There are steak Sundays that include a tasty non-alcoholic ginger beer – a weekly treat. There is also Yoga everyday from 1:00 p.m.to 2:00 p.m. I brought one of my yoga DVDs from home as did others so we have a variety of programs and do not get bored. The standing poses are difficult on a moving ship, but I manage to get through it.

I am beginning to realize that I enjoy my time on the winch with Chameleon because that is the only time I am physically alone. I am thinking to myself how crazy and scary it is that my idea of spending quality alone time involves a noisy sampling instrument! But alas, even Chameleon cannot make up for the fact that I miss my own private bathroom.

One morning while waiting for the sunrise on the bow, I was treated to quite a show of jumping fish. The fish are tuna and are jumping to avoid predators. I have seen jumping fish many times while on the winch, but never so many and for such an extended period of time. They continued their performance until well after breakfast. I shot this video shortly after breakfast.

Jacquelyn Hams: 24 November 2011

NOAA Teacher at Sea
Jackie Hams
Aboard R/V Roger Revelle
November 6 — December 10, 2011

Mission: Project DYNAMO
Geographical area of cruise: Leg 3, Eastern Indian Ocean

Date: November 24, 2011

Weather Data from the R/V Revelle Meteorological Stations

Time: 0830
Wind Direction: 246.10
Wind Speed (m/s): 9.3
Air Temperature (C): 27.4
Relative Humidity: 86.1%
Dew Point: (C): 25.10
Precipitation (mm): 25.1

PAR (Photosynthetically Active Radiation) (microeinsteins): 177
Long Wave Radiation (w/m2): 454.3
Short Wave Radiation (w/m2): 36.7

Surface Water Temperature (C): 300
Sound Velocity: 1545.9
Salinity (ppm): 35
Fluorometer (micrograms/l): 0.9
Dissolved Oxygen (mg/l): 2.6
Water Depth (m): 4637

Wave Data from WAMOS Xband radar

Wave Height (m) 2.2
Wave Period (s): 15.3
Wavelength (m): 290
Wave Direction: 29000

Science and Technology Log

Aerosols Group

 The Aerosols Group consists of Derek Coffman, Langley Dewitt and Kristen Schultz from the NOAA Pacific Marine Environmental Lab (PMEL) in Seattle, Washington. The Aerosols group measures the chemical, physical, and optical properties of sub and supermicron aerosols (liquids or solids suspended in gas) in the lowest layer of the troposphere. Aerosols are important in the study of climate change and the largest unknown due to the complicated nature of the particles. Aerosols are being studied in the MJO experiment to determine how they affect the radiative balance and how the MJO affects aerosols.

The measurements and analyses include:

  • real-time and filter-based analysis of the aerosol chemical composition
  • size distributions from 20 nm to 10 microns (aitken mode to course mode aerosols)
  • particle number concentrations
  • aerosol scattering and absorption
  • cloud condensation nuclei (CCN)
  • total mass of filtered collected aerosol
  • O3 and SO2 gas phase measurements.

Aerosols are captured via an opening in the inlet (mast). The base of the inlet consists of 21 individual sample lines. The inlet is designed to collect particles in average marine conditions without preferentially selecting particles and is efficient in collecting particles up to 10 microns in diameter.  Each sample line connects to a specific instrument for analysis. The captured aerosols are sampled for physical, chemical, and optical properties. . In general, for the ocean, particle sizes that are <1 micron are typically more anthropogenic, while particles >1 micron are sea salts and generated by wind and rain.

Aerosols are captured through the Inlet (mast).
Aerosols are captured through the Inlet (mast).
Base of aerosol inlet with sample lines.
Base of aerosol inlet with sample lines.

Impactors are attached to the sample lines to separate and collect aerosols. Each impactor has a filter to capture a particular particle size range. The filters are removed from the Impactors in a clean lab for analysis. Half of the samples collected are analyzed on the ship and the remaining samples are analyzed at the NOAA PMEL Lab in Seattle, WA. Analytical methods used on the ship to measure chemical species are ion chromatography, liquid chromatography with mass spectrometry (LCMS), total organic carbons (TOC), and organic carbon and elemental carbon (OCEC). The optical properties measured include scattering and absorption. Scattering is measured by an instrument called a nephelometer and absorption is measured by a Particle Soot Absorption Photometer (PSAP). The physical properties measured are total particle concentration and size distribution of the particles. Condensation particle counters (CPCs) measure the particle concentrations and size distribution is measured by a Scanning Mobility Particle Sizer (SMPS), The Aerosol Mass Spectrometer measures the size and chemical composition of non-refractory submicron aerosols.

Kristen removes impactor for sampling
Kristen removes impactor for sampling
Vacuum Pump closet houses vacuum and pressure needs for the aerosol vans.
Vacuum Pump closet houses vacuum and pressure needs for the aerosol vans.
Filters are removed from the impactor.
Filters are removed from the impactor.
Example of a clean filter (left) and sampled filter containing exhaust from the ship (right).
Example of a clean filter (left) and sampled filter containing exhaust from the ship (right).
The Aerosol Mass Spectrometer captures and analyzes the chemical composition of aerosol particles in near real time (every 5 minutes).
The Aerosol Mass Spectrometer captures and analyzes the chemical composition of aerosol particles in near real time (every 5 minutes).
Derek in the Aerosol van pictured with various instrumentation.
Derek in the Aerosol van pictured with various instrumentation.
The diagrams pictured above are based on a model prepared by Derek Coffman. The back trajectories on the left show that sub micron aerosols are dominant in the continental air mass and there is also more organic aerosol that is likely causing the absorption in the continental air mass. The clean marine diagram shows that sub micron aerosol is greatly reduced and aerosols >1 micron (coarse mode) play a dominant role in scattering in the air mass.
The diagrams pictured above are based on a model prepared by Derek Coffman. The back trajectories on the left show that sub micron aerosols are dominant in the continental air mass and there is also more organic aerosol that is likely causing the absorption in the continental air mass. The clean marine diagram shows that sub micron aerosol is greatly reduced and aerosols >1 micron (coarse mode) play a dominant role in scattering in the air mass.

Personal Log

Thanksgiving week proved to be the most interesting weather of the cruise. The winds picked up to 48 knots on Thanksgiving Day. This made for a real exciting time on the winch. During several drops (each time Chameleon is lowered in the water column), I had to hold on to the canopy with one hand, and the winch with the other so I would not fall over when the swells hit the stern of the ship.

I was surprised that Chief Scientist Jim Moum continued to work on his computer and did not run out to snatch me away from his valuable research instrument! If he had that much confidence in my ability to handle the situation, I had to prevail. Just as I was convincing myself I had to prevail, I heard the bridge call on the hand-held radio. I could not understand the communication and did not want to release the winch since it was difficult to control in the wind. Someone from the Ocean Mixing Group came out to tell me that the bridge called and could not control the ship direction and to take Chameleon out of the water. By this time Chameleon was trailing behind the ship and I could not see if it had gone under the ship. A bit of chaos ensued and I saw a boat hook out of the corner of my eye as crew prepared to get Chameleon out. Somewhere in the midst of the chaos, Jim Moum came on deck and decided that profiling could continue. By that time the ship had re-positioned, however, the wind speed was the same. Jim surveyed the situation and said that he had profiled in far worse weather conditions and went back to his work. I breathed a huge sigh of relief when my shift was over that night and Chameleon was not damaged.

Thanksgiving Day was another day of collecting data. The cooks prepared a Thanksgiving Dinner and I think I speak for all of the scientists when I say we appreciated the turkey and all the trimmings.

Scott, a Wiper in the Engineering Department asked me if I would like an interesting video of a crew job for the website. Scott is a polite crew member and has an interest in education. My first question was “What is the job description for a wiper?” I was told that a wiper is an unlicensed engine room staff member. According to Scott, he empties trash, cleans, and performs other projects as needed such as needle gunning (removing paint and rust from metal surfaces) natural air vent shafts as seen in the video below. I wasn’t prepared for the noise when I shot this video.

There are no gorgeous sunrise and sunset photographs to end this blog – we are probably in the beginning stages of the MJO. There is a tropical cyclone to our north and the outer bands were reaching the ship. We are experiencing squalls with high winds. It is unusual to have cyclones during the MJO event – they usually develop in the wake of the cycle according to the Atmospheric Soundings Group. I get dressed in rain boots and gear and run to the winch and run back inside when my shift is over. Although I am sure you would like to see a photo, it is not exactly a desirable Kodak moment for cameras. Stay tuned, the weather is bound to change.

For this post’s quiz, please answer in the comments of this post:

Using the Aerosol source diagram above, what particle size aerosols are dominant in
continental air masses and what particle size aerosols are dominant in clean marine air masses?

 

Jacquelyn Hams: 14 November 2011

NOAA Teacher at Sea
Jackie Hams
Aboard R/V Roger Revelle
November 6 — December 10, 2011

Mission: Project DYNAMO
Geographical area of cruise: Leg 3, Eastern Indian Ocean

Date: November 14, 2011

Weather Data from the R/V Revelle Meteorological Stations

Time: 1045
Wind Direction: 262.60
Wind Speed (m/s): 135.8
Air Temperature (C): 28
Relative Humidity: 79.7%
Dew Point: (C): 24.20
Precipitation (mm): 42.4

PAR (Photosynthetically Active Radiation) (microeinsteins): 1101.5
Long Wave Radiation (w/m2): 410.3
Short Wave Radiation (w/m2): 192.5

Surface Water Temperature (C): 29.8
Sound Velocity: 1545.1
Salinity (ppm): 34.8
Fluorometer (micrograms/l): 0.2
Dissolved Oxygen (mg/l): 2.8
Water Depth (m): 4637

Wave Data from WAMOS Xband radar

Wave Height (m) 1.3
Wave Period (s): 13.2
Wavelength (m): 236
Wave Direction: 2800

Science and Technology Log

Ocean Mixing

All about CTDs

A CTD is a standard instrument used on ships to measure conductivity, temperature and depth. Three CTD systems are being used during Leg 3 of Project DYNAMO to measure CTD.

  • The Revelle deploys the ship’s CTD twice a day to a depth of 1,000 m. The CTD measurements can be viewed on a monitor in the computer room.
Ship's CTD
Ship's CTD
Ship's CTD in water
Ship's CTD in water
Ship's CTD data display
Ship's CTD data display
Data obtained from the ship's CTD
Data obtained from the ship's CTD
  • The Ocean Mixing group is using a specialized profiling instrument that was designed, constructed, and deployed by the microstructure group at the College of Oceanic and Atmospheric Sciences, Oregon State University. The instrument, called “Chameleon”, measures CTD and turbulence. Chameleon takes continuous readings to a depth of 300 m as it is lowered through the water column. The top of the instrument has brushes to keep the instrument upright in the water and make it hydrodynamically stable so that very precise measurements of turbulence can be achieved. These measurements allow computations of mixing, hence the name Ocean Mixing Group. The instrument freely falls on a slack line to a depth of 300 m after which it is retrieved using a winch. The Chameleon has been taking continuous profiles at the rate of about 150/day since we have been on station and will continue taking measurements for the next 28 days.
Photograph of Chameleon
Photograph of Chameleon
Close-up of Chameleon's sensors
Close-up of Chameleon's sensors
Data obtained from the Chameleon
  • The T Chain CTD aboard the ship was also designed by the microstructure group at the College of Oceanic and Atmospheric Sciences, Oregon State University. This instrument measures CTD in the near-surface (upper 10 m) using bow chain-mounted sensors (7 Seabird microcats + 8 fast thermistors). The T Chain takes data every 3 seconds, and although that is not very fast, the data is extremely accurate (within 1/1000th of a degree – 3/1,000th of a degree). The T Chain is mounted on the bow and has been taking measurements continuously since we have been on station. These measurements focus on the daytime heating of the sea surface and the freshwater pools created by the extreme rainfall we have been observing and which is associated with the MJO.
Photograph of T Chain
Photograph of T Chain
Data obtained from T Chain
Data obtained from T Chain

NOAA High Resolution Doppler LIDAR (Light Detection And Ranging) Group

A Brief Introduction to LIDAR

The following introduction to LIDAR systems was provided by Raul Alvarez.

In LIDAR, a pulse of laser light is transmitted through the atmosphere. As the pulse travels through the atmosphere and encounters various particles in its path, a small part of the light is scattered back toward the receiver which is located next to the transmitter. (You may have seen similar scattering off of dust particles in the air when sunlight or a laser pointer hits them.) The particles in the atmosphere include water droplets or ice crystals in clouds, dust, rain, snow, aircraft, or even the air molecules themselves. The amount of signal collected by the receiver will vary as the pulse moves through the atmosphere and is dependent on the distance to the particles and on the size, type, and number of particles present. By keeping track of the elapsed time from when the pulse was transmitted to when the scattered signal is detected, it is possible to determine the distance to the particles since we know the speed of the light.

Once we know the signal at each distance, it is now possible to determine the distribution of the particles in the atmosphere. By measuring how the light was affected by the particles and the atmosphere between the LIDAR and the particles, it is possible to determine things such as the particle velocity which can yield information about the winds, particle shape which can indicate whether a cloud is made up of water droplets or ice crystals, or the concentration of some atmospheric gases such as water vapor or ozone. The many kinds of LIDARs are used in many different types of atmospheric research including climate studies, weather monitoring and modeling, and pollution studies.

Typical lidar signal as a funciton of range
Typical lidar signal as a function of range
Photograph of Ann and Raul inside the LIDAR van.
Photograph of Ann and Raul inside the LIDAR van.
Raul explains the inner workings of LIDAR aboard the ship. From left to right: 1st photo shows Raul and the LIDAR system; 2nd and 3rd photos display the optical components of the LIDAR; 4th photo is the rotating scanner base.
Raul explains the inner workings of LIDAR aboard the ship. From left to right: 1st photo shows Raul and the LIDAR system; 2nd and 3rd photos display the optical components of the LIDAR; 4th photo is the rotating scanner base.
The four cone-shaped devices are differential GPS antennae used to correct for the motion of the boat.
The four cone-shaped devices are differential GPS antennae used to correct for the motion of the boat.

An integrated motion compensation system is used to stabilize the scanner to maintain pointing accuracy. As you can see from the video below, the scanner maintains its position relative to the horizon while the ship moves.

The slides below represent a Doppler LIDAR data sample from Leg 3 of the Revelle cruise. The images and slides were provided courtesy of Ann Weickmann.

Image credit: Ann Weickmann
Image credit: Ann Weickmann
Image Credit: Ann Weickmann
Image Credit: Ann Weickmann
Image credit: Ann Weickmann
Image credit: Ann Weickmann
Image credit: Ann Weickmann
Image credit: Ann Weickmann
Image credit: Ann Weickmann
Image credit: Ann Weickmann

Personal Log

The R/V Revelle is not a NOAA ship. It is part of the University-National Oceanographic Laboratory System (UNOLS) and part of the Scripps Institution of Oceanography research fleet. A few crew members were kind enough to take time from busy schedules to talk with me about their careers. Students may find these interviews interesting especially if they are exploring career options.

The food aboard the Revelle is very good thanks to our cooks, Mark and Ahsha. They are very friendly crew members and always happy to accommodate the diverse eating schedules of scientists who have to work during meal hours.

Mark Smith, Senior Cook
Mark Smith, Senior Cook
Ahsha Staiger, Cook
Ahsha Staiger, Cook

Meanwhile back on the winch, I am beginning to get the hang of it. I will not say that I am comfortable, because I am always aware that I am in charge of a very expensive piece of equipment. I alternate between operating the winch, operating the computer, standby time (to assist as needed) and free time.

Jackie on the computer in the Hydro lab.
Jackie on the computer in the Hydro lab.
Dramatic cloud formation at sunrise.
Dramatic cloud formation at sunrise.

Jacquelyn Hams: 13 November 2011

NOAA Teacher at Sea
Jackie Hams
Aboard R/V Roger Revelle
November 6 — December 10, 2011

Mission: Project DYNAMO
Geographical area of cruise: Leg 3, Eastern Indian Ocean

Date: November 13, 2011

Weather Data from the R/V Revelle Meteorological Stations

Time: 810
Wind Direction: 262.400
Wind Speed (m/s): 2.7
Air Temperature (C): 28.1
Relative Humidity: 77.3%
Dew Point: (C): 23.7
Precipitation (mm): 40.2

PAR (Photosynthetically Active Radiation) (microeinsteins): 2092.5
Long Wave Radiation (w/m2): 413.3
Short Wave Radiation (w/m2): 442.7

Surface Water Temperature (C): 29.50
Sound Velocity: 1544.8
Salinity (ppm): 35.2
Fluorometer (micrograms/l): 69.7
Dissolved Oxygen (mg/l): 3.2
Water Depth (m): 4637

Wave Data from WAMOS Xband radar

Wave Height (m) 0.7
Wave Period (s): 8.1
Wavelength (m): 103
Wave Direction: 2090

Science and Technology Log

Atmospheric Soundings

In addition to launching radiosondes, the Atmospheric Soundings Group operates a Wind Profiler to observe air mass density directly above the radar. Each beam sends back a return and more returns indicate humid or rainy conditions. The wind profiler operates twenty-four hours a day on the ship. The wind profiling is revolutionary for this cruise in that 8 profiles per day will be performed by three people who are dedicated to this experiment.  This detail will allow the scientists to see small scale variations in the atmosphere that have not been seen in the past with fewer profiles.

Wind Profiler displays light winds and little air movement (left).  Colors indicate high intensity and fast air movement (right). The image on the right was captured during an episode of rainfall.
Wind Profiler displays light winds and little air movement (left). Colors indicate high intensity and fast air movement (right). The image on the right was captured during an episode of rainfall.

Ocean Optics

The Ocean Optics team is led by KG Fairbarn of the Earth Research Institute at the University of California Santa Barbara.  KG does three optics casts a day using a Microprofiler.  The data can be viewed on the computer in real time as the instrument is lowered through the water column to a depth of 50 meters. The Microprofiler measures the irradiance within the visible light spectrum.

Irradiance is defined as the measure of solar radiation on a surface in watts/m2.The amount of irradiance absorbed within the water column is a function of chlorophyll and nutrients. The Microprofiler contains a flourometer to measure chlorophyll and KG obtains the nutrient content from water samples collected from the Revelle CTD.

In terms of Project DYNAMO, KG is measuring light that penetrates a layer of water and heat that penetrates the ocean. This information allows scientists to quantify the heat distribution through the water column and relate it to the flux (transfer or exchange of heat) at the surface and flux at the air-sea interface.

Revelle CTD with Niskin bottles attached for collecting water samples
Revelle CTD with Niskin bottles attached for collecting water samples

Personal Log

Life at Sea

What is it like to live aboard a ship that is operating 24/7? There are negatives and positives. It is busy and often noisy. Doors are always closing and opening and the maintenance is constant. Privacy is non-existent.  I often get up early and go on the bow to watch the sunrises and sunsets and to get some quiet time.  However, I don’t have much time to ponder the negatives of life at sea as I am very busy familiarizing myself with and reporting on all 7 science groups. I work a split watch with the Ocean Mixing Group between 1500 and 2100. In addition, I am creating, posting, and grading assignments for my classes at Los Angeles Valley College.

On a positive note, the science teams are interesting, happy with their work, and pleasant to work with. I share a room with another scientist where I have the top bunk. I share lab “office space” with the Atmospheric Soundings group, but float around the ship to the library and other spots for a change of scenery.  There is always something good to eat and every day there has been a fresh salad bar at lunch and dinner.  The cooks are really nice and try hard to please everyone on the ship which everyone knows is an impossible task.

 

I find a quiet space to take notes.
I find a quiet space to take notes.
Sometimes we get visitors on deck.
Sometimes we get visitors on deck.
Office lab mates Lou Verstraete, National Center for Atmospheric Research (left), and Jonathan Wynn Smith, Ph.D. student, Howard University (right).
Office lab mates Lou Verstraete, National Center for Atmospheric Research (left), and Jonathan Wynn Smith, Ph.D. student, Howard University (right).

I was surprised that non-plastic biodegradable materials are dumped at sea and there is a lot of it on a cruise that lasts this length of time. The plastic is burned on the ship in an incinerator. Also, the ship engines operate 24/7 to keep the ship in a fixed location (the term used for a fixed location is “on station”).

Inside the incinerator room.
Inside the incinerator room.
Entrance to the incinerator room.
Entrance to the incinerator room.

Overall, the positives outweigh the negatives on this cruise. My work with the Ocean Mixing Group is going very well and the other scientists are extremely helpful and often contribute to the development of lesson plans for the classes I am teaching from the ship. The positive attitudes of these researchers more than compensates for any negative parts of the cruise. And, as I mentioned in a previous posting, there are endless opportunities for interesting photographs.

 Meteorologists would like this cloud formation.
Meteorologists would like this cloud formation. (Photo By Jackie Hams)
This photograph is actually a red moon at night.
This photograph is actually a red moon at night. (Photo By Jackie Hams)