Debra Brice, November 16, 2003

NOAA Teacher at Sea
Debra Brice
Onboard R/V Roger Revelle
November 11-25, 2003

Mission: Ocean Observation
Geographical Area: Chilean Coast
Date: November 16, 2003

Data from the Bridge
1.  161700Z Nov 03
2.  Position: LAT: 20-10.6’S, LONG: 085-08.0’W
3.  Course: Hove to
4.  Speed: 0 Kts
5.  Distance: 20.8 NM
6.  Steaming Time:  1H 48M
7.  Station Time:  22H 12M
8.  Fuel: 2215 GAL
9.  Sky: Ptly Cldy
10. Wind: 120-T, 14 Kts
11. Sea: 120-T, 2-3 Ft
12. Swell: 150-T, 3-5 Ft
13. Barometer: 1019.7 mb
14. Temperature: Air: 20.3 C, Sea 19.5 C
15. Equipment Status: NORMAL
16. Comments: On station in vicinity of WHOI buoy.

Science and Technology Log

We are at the STRATUS buoy from last year and are preparing to trigger the acoustical releases so that the glass ball floats will bring up the instruments, almost 50 of them!  it will take about 40 minutes from triggering the release until they surface and they the retrieval will begin in earnest.  We will spend the day bring them all aboard, recording the depth, serial number and condition of each of them before Dr. Weller’s group will begin downloading the data.  Then we will clean them and begin to pack them for the return to WHOI. A little background on the project first:  The purpose of the cruise was to recover and then deploy a well-instrumented surface mooring under the stratocumulus clouds found off Chile and Peru in the vicinity of 20’S and 85’W.  The mooring has been deployed for  for 3 years as a component  of the Enhanced Monitoring element of the Eastern Pacific Investigation of Climate ( EPIC) programs.  Cruises for recovery and redeployment have occurred each October or November.  The science objectives of the Stratus Project are to observe the surface meteorology and air-sea exchanges of heat, freshwater, and momentum, to observe the temporal evolution of the vertical structure of the upper 500m of the ocean.  This year the Stratus project was joined by the ETL/NOAA group out of Boulder, Colorado.  The Environmental Technology Laboratory people are meteorologists who are looking at the formation of the stratocumulus clouds that are formed off the coast of Chile and Peru.  They brought and are using cloud radar and radiosondes to look at these phenomena. The Stratus moorings carry two redundant sets of meteorological sensors and the mooring line also carries a set of oceanographic instruments.  Although Acoustic rain gauges were deployed on the last 3 moorings, this year there will not be one on the buoy and there will be several more current meters and temperature gauges.  The Chlorophyll sensors will not be on the new one either.

Types of measurements taken by Stratus moorings:

  • Surface measurements
  • Subsurface measurements
  • Wind speed
  • Water temperature
  • Wind direction
  • Conductivity
  • Air temperature
  • Current speed
  • Sea Surface temp
  • Salinitybarometric pressure
  • Current direction
  • Relative humidity
  • Incoming short-wave radiation
  • Incoming long wave radiation
  • Precipitation

Most of the equipment , including the new buoy, was loaded on the R/V REVELLE in San Diego with some of the equipment being shipped to Guayaqil, Ecuador and loaded onboard in Manta, Ecuador.  The science party flew into Manta to meet the ship and we will fly out of Arica to return to the U.S. On November 15, we stopped to lower and test the acoustic releases to be used in the mooring.  They were lowered to  500,  and 1500m depths.  Jason Smith (WHOI) communicated with the releases at each depth.  After the release test two CTD casts were made to 4000m.  When we arrived at the buoy mooring ship and buoy data comparisons began.  This is a check to see whether the sensors on the mooring are still calibrated. At 7:20 the release of the glass balls was triggered and they should surface about 45 minutes later.  The small boat will go out to put a line on the mooring and bring it back to the ship.  The line will be secured on deck the the recovery will begin.  As the instruments are brought onboard they will be laid out in the order they are hung on the mooring up the starboard side of the ship and photographed and labeled by depth and type of instrument.  This is to document the condition of each instrument before cleaning begins.  Most of the instruments are covered by barnacles and a host of other organisms, this is termed Bio-fouling.  The bio-fouling is dominated by goose-neck barnacles.  These are quite thick on the buoy hull and down to 30m; some goosenecks were even found down to 135m last year.  These can be quite a problem for the data collection, for example: last year the floating SST on the buoy hull was stuck in the down position by the barnacles.  This is why it is important to document the condition of the instruments with photographs so that when you are looking at your data and it suddenly changes or stops you might get some clue as to why the flow on the current meters changes significantly in one of the sensors ( bio-fouling for example).  We will finish recovery of the instruments today and tomorrow will recover the buoy late today.

Personal Log

Went out on the zodiac in the morning to look over the buoy.  Sunny, beautiful, water was 20’C and 30 to 35′ visibility.  There were 3′ swells and it was a wonderful view of the REVELLE, see the attached photos.  Many fish around the buoy and there will be many around the back of the boat today when we bring up the mooring.  We are 800 miles off the coast of Chile and the ship is in water  of about 4400m depth.  Nothing but blue ocean all around and it is breathtaking, reminds you why oceanographers go to sea.  You are surrounded by a mysterious blue liquid and it becomes a lifelong fascination to learn what lies beneath.  We began our “Fantail Interviews” last night with the chief engineer, Paul Mauricio, Nan Galbraith, WHOI Information systems associate and Paquita Zuidema a scientist with NOAA Environmental Technology Laboratory.  We talked about their research, jobs and experiences working at sea.  Our first videos should be online today.  We will be touring the ship and video taping interviews with other science party and crew members all week as well as filming the work onboard. There is something special about being part of science as the observations are made.  Jason was checking his aerosol readings last night and sharing his graphs.  He was seeing some things he expected and some he didn’t.  Many things he was seeing had as much to do with visual observations of the changing cloud shapes and precipitation as the sensor readings.  This kind of on-site observation is irreplaceable in science and definitely what makes science exciting.  Chris Fairwell of ETL was talking about the stratocumulus formations and how the behavior of the clouds was not necessarily what was expected, but then observations in this area had never really been done before and this was really exciting.  For me as a teacher it is interesting because these are things that my students can share by logging onto the internet and seeing on various NOAA , WHOI and SIO web sites as well as many other good science web sites and no text book can hope to compare with this.  We can also e-mail these scientists to ask questions about what they are seeing and a possible explanation.  Well they just call the acoustical release and may watch is almost over which just means the real work begins:)


Leave a Reply

%d bloggers like this: