NOAA Teacher at Sea
Aboard R/V Roger Revelle
November 6 — December 10, 2011
Mission: Project DYNAMO
Geographical area of cruise: Leg 3, Eastern Indian Ocean
Date: November 7, 2011
Weather Data from the R/V Revelle Meteorological Stations
Course on Ground
Wind Direction: 195.50
Wind Speed (m/s): 2.1
Air Temperature (C): 27.6
Relative Humidity: 81.7%
Dew Point: (C): 24.4
Precipitation (mm): 6.0
PAR (Photosynthetically Active Radiation) (microeinsteins): 517.4
Long Wave Radiation (w/m2): 405.3
Short Wave Radiation (w/m2): 60.5
Surface Water Temperature (C): 28.7
Sound Velocity: 1540.6
Salinity (ppm): 32.45
Fluorometer (micrograms/l): 65.2
Dissolved Oxygen (mg/l): 3.6
Wave Data from WAMOS Xband radar
Wave Height (m) 1.6
Wave Period (s): 18.4
Wavelength (m): 312
Wave Direction: 2650
Science and Technology Log
Leg 3 of the Project DYNAMO research cruise began, on November 6, 2011 from Phuket, Thailand at approximately 1430. The DYNAMO Leg 3 research cruise consists of seven scientific groups conducting experiments in the following areas:
- Surface Fluxes
- Atmospheric Soundings
- NOAA High Resolution Doppler LIDAR
- TOGA Radar
- Ocean Optics
- Ocean Mixing
My primary role on this cruise is to work with the Ocean Mixing group led by Dr. Jim Moum from Oregon State University. The Ocean Mixing Group is responsible for sonar measurements of ocean current profiles, high frequency measurement of acoustic backscatter, turbulence/CTD profiling instruments and near surface CTD (Conductivity, Temperature, Depth) measurements. I will be working with other scientific groups as needed and have organized my Teacher at Sea blog to report on daily activities by science group.
We have been cruising for a couple of days to the sampling station in the eastern Indian Ocean and are still within the Exclusive Economic Zones (EEZ) of Thailand, India, and other countries. Here is an interesting fact that I learned about the EEZ – it not only applies to resources, but also applies to data collection. What this means to the R/V Revelle, is that the scientists cannot collect data until the ship clears the 200 nautical mile EEZ for the counties. After clearing the EEZ, the science groups can begin data collection.
Data collection began on the ship on November 8 and one of the first groups I observed was the Atmospheric Soundings group. This group is responsible for launching radiosondes using helium balloons (weather balloons). A radiosonde is an instrument that contains sensors to measure temperature, humidity, pressure, wind speed, and wind direction. Although the balloons can hold up to 200 cubic feet of helium, on this cruise, each balloon is filled with 30-35 cubic feet of helium. As the radiosonde ascends, it transmits data to the ship for up to 1 ½ hours before the weather balloon bursts and falls into the ocean. The weather balloons have been reaching an average altitude of 16 km before bursting. Approximately 260 weather balloons will be launched during Leg 3 of the cruise.
Watch the video clip below to watch the deployment of a weather balloon.
The Ocean Mixing group began the deployment of XBTs (Expendable bathythermographs) on November 10, 2011. XBTs are torpedo shaped instruments which are lowered through the ocean to obtain temperature data. The XBT is attached to a handheld instrument for launching by a copper wire. Electronic readings are sent to the ship as the XBT descends in the ocean. When the XBT reaches 1,000 meters, the copper line is broken and the XBT is released and falls to the bottom on the ocean.
I arrived in Phuket, Thailand on November 3, 2011 after a 19-hour plane ride. After dinner and a good night’s sleep, I went to the ship to get acquainted with my new home for the next 6 weeks. Select the link below for a tour of the R/V Revelle.
The Revelle sailed from Phuket on November 6. As the ship sailed to station, I captured the beauty of the Indian Ocean.