Science Objective

To explore the potentials and limitations of perturbation experiments at sea.

Goals:

  1. Following local blooms and features
  2. Eddy sampling experiments
  3. Ship deck incubation experiments
  4. Ship lab incubation experiments
  5. pH shift experiments

Rationale

To develop experimental tools for predicting responses of microbial communities to physical and chemical forcing.

Approach

We will try to observe and interpret natural perturbations such as local blooms and eddies. We will also perform, observe, and interpret artificial perturbations including ship-deck incubations, and lab-scale manipulation experiments.

Scientific Operations

Transect / Stations

Time / Station

Activities

Hawai‘i
22.5N, 157.50W
100 nm, 10 hrs

July 30, 08:00
July 30, 18:00

Underway thermosalinograph, fluorometry, FRRf

22.50N, 157.50W

Station 1: Upwelling eddy

Min core CTD/ Science CTD, two casts for deep water enrichment, one cast for DOM incubation

22.50N, 157.50W
22.750N, 157.00W
31 nm, 3.0 hrs

July 31, 02:30
July 31, 06:00

Underway thermosalinograph, fluorometry, FRRf

22.75N, 157.00W

Station 2-18
BLOOM mapping
July 31-Aug 08

Bloom location. Extensive sampling of bloom spatial characteristics, 40+ CTD casts (Min/Full core & Science), sediment traps deployment, SID deployment, pumping CTD operation, Deep water enrichment, Nitrogen fixation, Herve's floats deployment

22.75N, 157.00W
22.75N, 155.20W
99 nm, 10 hrs

Aug 08, 23:00
Aug 09, 09:00

Underway thermosalinograph, fluorometry, FRRf

22.75N, 155.20W

Station 19: Downwelling eddy

Full Core CTD/Science CTD

22.75N, 155.20W
23.50N, 154.00W
80 nm, 8 hrs

Aug 09, 12:30
Aug 09, 20:30

Underway thermosalinograph, fluorometry, FRRf

23.50N, 154.00W

Station 20: Upwelling eddy

Full Core CTD/Science CTD

23.50N, 154.00W
25.50N, 152.50W
145 nm, 14.5 hrs

Aug 10, 00:00
Aug 10, 14:30

Underway thermosalinograph, fluorometry, FRRf

25.50N, 152.50W

Station 21: Downwelling eddy

Full Core CTD/Science CTD

25.50N, 152.50W
25.50N, 154.00W
81 nm, 8 hrs

Aug 10, 18:00
Aug 11, 02:00

Underway thermosalinograph, fluorometry, FRRf

25.50N, 154.00W

Station 22: Downwelling eddy

Min Core CTD/Science CTD

25.50N, 154.00W
25.50N, 155.50W
81 nm, 8hrs

Aug 11, 04:00
Aug 11, 12:00

Underway thermosalinograph, fluorometry, FRRf

25.50N, 155.50W

Station 23: Upwelling eddy

Full Core CTD/Science CTD

25.50N, 155.50W
25.50N, 156.00W
30 nm, 3 hrs

Aug 11, 15:30
Aug 11, 18:30

Underway thermosalinograph, fluorometry, FRRf

25.50N, 156.00W

Station 24: Eddy sampling 1

Min Core CTD/Science CTD

25.50N, 156.00W
25.50N, 156.50W
30 nm, 3 hrs

Aug 11, 20:30
Aug 11, 23:30

Underway thermosalinograph, fluorometry, FRRf

25.50N, 156.50W

Station 25: Eddy sampling 2

Min Core CTD/Science CTD

25.50N, 156.50W
25.50N, 157.00W
30 nm, 3 hrs

Aug 12, 01:30
Aug 12, 04:30

Underway thermosalinograph, fluorometry, FRRf

25.50N, 157.00W

Station 26: Eddy sampling 3

Min Core CTD/Science CTD

25.50N, 157.00W
25.50N, 157.50W
30 nm, 3 hrs

Aug 12, 06:30
Aug 12, 09:30

Underway thermosalinograph, fluorometry, FRRf

25.50N, 157.50W

Station 27: Eddy sampling 4

Full Core CTD/Science CTD

25.50N, 157.50W
25.50N, 158.00W
30 nm, 3 hrs

Aug 12, 13:00
Aug 12, 16:00

Underway thermosalinograph, fluorometry, FRRf

25.50N, 158.00W

Station 28: Eddy sampling 5

Min Core CTD/Science CTD

25.50N, 158.00W
25.50N, 158.50W
30 nm, 3 hrs

Aug 12, 18:00
Aug 12, 21:00

Underway thermosalinograph, fluorometry, FRRf

25.50N, 158.50W

Station 29: Eddy sampling 6

Min Core CTD/Science CTD

25.50N, 158.50W
25.50N, 159.00W
30 nm, 3 hrs

Aug 12, 23:00
Aug 13, 02:00

Underway thermosalinograph, fluorometry, FRRf

25.50N, 159.00W

Station 30: Eddy sampling 7

Min Core CTD/Science CTD

25.50N, 159.00W
23.75N, 159.00W
105 nm, 10.5 hrs

Aug 13, 04:00
Aug 13, 14:30

Underway thermosalinograph, fluorometry, FRRf

23.75N, 159.00W

Station 31: Eddy sampling 8

Full Core CTD/Science CTD

23.75N, 159.00W
21.30N, 158.80W
130 nm, 14 hrs

Aug 13, 18:00
Aug 14, 08:00

Underway thermosalinograph, fluorometry, FRRf

21.30N, 158.80W

Aug 14, 08:00

Arrive Snug Harbor, Unload ship

NOTE:

  1. The bloom at 23N, 159W has faded away. There is another bloom developing at 22.75N 157.99W (Fig. 1). Ocean color data indicate that the bloom slowly moves north-west. The exact position of bloom experiment will be defined by FRR fluorometry survey once we arrive at the expected bloom location.
  2. The remainder of the cruise track is defined by the most actual position of upwelling/downwelling eddies within 22N \96 26N and 152W-160W positions (Fig. 2).

image of fig1
Figure 1: Most recent bloom position (click to see larger version).

image of fig2
Figure 2: KM0814 cruise track (click to see larger version).

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