16 August 2007
I8S/I9N letter for participants

Dear Colleagues,

As nearly all of you know, the I8S/I9N cruise for the US Global Ocean Carbon and Repeat Hydrography program will be carried out in early 2007, ahead of the schedule in our 2002 proposal. The originally-planned S4P/P16S cruise for 2007 has not yet been scheduled and so is considered postponed. The I8S/I9N cruise is presently planned for R/V Roger Revelle, on this preliminary schedule:

03 FEB 2007 lv Dunedin, NZ, for I8S
19 MAR 2007 ar Perth
23 MAR 2007 lv Perth for I9N
01 May 2007 ar Columbo, Sri Lanka

The cruise plan as it stands at the moment is copied at the end of this email. A careful reader may note a slight discrepancy between it and the ship schedule. This discrepancy will be resolved soon.

Presently I am scheduled to be chief scientist on the I8S leg, with Alex Orsi and Annie Wong as co-chief scientists. We hope that Janet Sprintall will be chief scientist on the I9N leg, with Chris Sabine and possibly another as co-chiefs, but I note that Janet has a busy schedule and so we may have to make an adjustment. I will keep you informed. For now I will be the point of contact.

As always, we will take at least two graduate students on each leg to work with the science team. An Announcement of Opportunity for grad students is attached. Please see that students who might be interested receive the announcement. Thanks.

CTD/hydrographic/data support at sea will be provided by the SIO Shipboard Technical Support Oceanographic Data Facility, working with STS personnel from the Resident Technician and Shipboard Computer groups.

IMPORTANT RE FUNDING: Because this cruise is out of the original schedule, is being run as an academic cruise instead of a NOAA-led cruise, and is now two major science legs in 2007 instead of one, seagoing groups will want to work with their program managers to see that their funding needs are being looked after. NOAA and NSF program managers are aware of the schedule shift and are prepared to work with you. If you were part of a consortia proposal in 2002 (e.g., CFCs & tracers, CO2), be sure to work it out within your consortium, too.

IMPORTANT RE CRUISE PLANNING: Please let me know soon if you will have a measurement program on board, what program that is, your lab requirements, if you are bringing a van on board, your sample requirements, the number of on-board personnel each leg you request, and any other information you think I should have. I will compile and redistribute this information. I would really like to have it by September 12th. Thanks.

IMPORTANT RE SHIPPING: You should not plan on shipping any I8S/I9N cargo on R/V Revelle when the ship leaves San Diego ca. 01 December 2006. (Revelle has a dead-head and one major science leg before ours.) I will request an exemption for normal amounts of our nearly-unshippable hazardous chemicals. If there is other cargo space available to us, I will tell you. But do not count on it. I will provide additional shipping information as soon as I can. You must work through me and the STS Resident Technicians regarding any cargo to be loaded in San Diego. Do not contact the SIO Marine Facility on your own about this issue.

Finally, the status of other sea work for the US program is as follows:

Line I6S, from South Africa to Antarctica, may be run in early 2008(January?(. At this writing the likely vessel is again R/V Roger Revelle. This is a single 40+ day leg.

NOAA hopes to run line P18S (two legs, Antarctica to Mexico, or vice versa), probably in early 2008.

There remains a _possibility_ that NSF will some year find us an ice-strengthened research ship for the leg we call “P16S/S4P” - the southmost extension of P16S plus some work around the Pacific/Indian sector of the Antarctic. Or it might not happen at all.

I am looking forward to working with you on this cruise.

Best Regards,
Jim Swift


Load: 3 days
Leg 1: 40 UNOLS days at sea
mid-cruise break: duration at operator's discretion
Leg 2: 41 UNOLS days at sea
unload: 2 days

Other facts:

Leg 1 = 6370 nautical miles, 87 stations, 2830 rosette water samples plus check samples for 44 trace metal casts. 11 days steam to first station; 4 days steam to port after final station.

Leg 2 = 5269 nautical miles, 105 stations, 3583 rosette water samples plus check samples for 53 trace metal casts. 4 days steam to first station; 4 days steam to port after final station.

This takes into account the following information:

  1. Ports

    Start port: Dunedin, NZ
    Mid-cruise port: Perth (or nearby), Australia
    End port: Colombo, Sri Lanka

    There is 11 days of steaming to the first station. So the equipment must be secure, but does not need to be 100% operational when departing Dunedin. The ship will be battling headwinds and opposing current on the long steam, thus my 11 knot estimate may be poor. A 10-knot over-the-ground speed would add somewhat more than 1 day to the steam to the first station.

    With 4 days steam to Colombo, there is time to do some packing at sea. So a 2-day unload in port should do it.

    I noted to the schedulers that the choice of ports is up to the operator, but that any changes will affect UNOLS days at sea, plus will have effects on scientific party budgets. Thus it is crucial that I be notified if/when any port changes are made.

  2. Trace metal program

    I added a 1-hour trace metal cast at every second station.

  3. Revised station time calculator.

    I used the best station time calculation algorithm at my disposal. It includes 10 minutes to slow the ship to station and launch the CTD, 2 minutes before beginning deployment, 10 extra minutes total for the first 100 and last 50 meters, 10 minutes to recover and secure the rosette and get underway, and 1.5 minutes to slow the winch, soak, and re-start the winch for each bottle. I used the Robbins/Swift/Sloyan bottle depth tables to determine the number of bottles per station, against the bottom depth at the station.

  4. Ship speed

    I used 11 knots over the entire track. (The station time calculator includes allowances for slowing and restarting at each station.)