Below are the daily updates for days 3 and 4 of our cruise.
And some plans for avoiding Bertha.
 |
| Our first sight of rain, looking out over the back of the ship |
Day 3
We spent most of the overnight hours steaming away to the south, which
is into the wind. While mostly everyone is sleeping, the aerosol sampler
on top of the bridge is turned on. To avoid contamination from the ship's
smoke stacks, it can only be on while we are headed into the wind. Around
3am, the students keeping tabs on the aerosol sampling turned it off so
we could head back towards our drifters.
 |
| Turning on the aerosol sampler |
All three drifters had been staying inside the eddy and were
following roughly the same path. When we went to look up their current
location to head back towards them, we realized we weren't getting any signal
from them! After a mad scramble to figure out why there was no data from
them, we ended up doing a quick estimate of where they should be, and started
heading there instead.
It turned out, that instead of losing three expensive drifters, it
was a mild case of operator error. The software program that receives the
signal had accidentally been shut down the night before, so we weren't getting
any of the data. Luckily, the drifters still collected data the entire
time, we just couldn't see it.
Once we made it back to the vicinity of the drifters, we did a CTD
cast and a trace metal CTD cast as well. That's when it began to rain.
We put out rain catchers, but had trouble collecting anything as the wind
was blowing the rain sideways, instead of down into our bucket.
 |
| Our weather forecast expert hard at work on the bridge |
We held off on sampling until the rain stopped, then did another
CTD cast to see how the mixed layer changed. We had planned another trace
metal CTD cast as well. But when we went to turn on the winch, there was
loud POP and some sparks and smoke. Turns out it is broken, and we don't
have the equipment on board to fix it.
 |
| Holding onto the trace metal CTD as the winch issues were investigated. |
The evening plan was to put the aerosol sampler and rain bucket
back out overnight and head into the wind again. Which leads us to...
Day 4
It rained again! We turned off the aerosol sampler and
closed the bucket to head back to the area where our drifters are around 2am.
Then, between 3 and 6am, we got another good bit of rain. BUT...
we didn't catch much because it was all after we took down the bucket!
We will still be able to see the effects of the rain on the surface
ocean, we just won't be able to do controlled laboratory tests with it.
 |
| Getting the rain catcher set up to run overnight. |
We did our early morning CTD cast, as usual. Then, we
deployed the towfish, which collects surface water samples. Our cruise
track for this portion should look pretty interesting, as we circled several
times to the left around the drifter location.
 |
| Consulting over the CTD profile data to determine where to sample |
Just before noon, we retrieved the towfish from the water and did
a PAR cast and another shallow CTD cast. We got lucky and right after
finishing these casts, it started raining again! Being rather desperate
for samples, we dropped everything and started chasing the rain, hoping to
collect some more. We got a bit, but not too much. The rain seemed
to dissipate as the system traveled north, and the main section was always just
out of reach.
Eventually we gave up and returned to our original position near
the drifters. We did a short CTD cast to see if there were any changes
from the brief rain event, and then went into our nightly aerosol collecting
routine.
Plans for Bertha
Bertha is now a tropical storm and is forecast to become a
hurricane on Wednesday. The latest forecast update we received showed a
significant change in position. Instead of barely clipping our current
position, there is now a 20-40% chance we will encounter tropical storm force
winds (above 30 knots). Since we will need to refuel in the next couple
of days anyways, we decided to head towards port Monday evening. We
should put in late afternoon Tuesday, and be back out sampling by Thursday
morning, if all goes well. Our stop will kill multiple birds with one
stone, as we avoid the storm, replace the broken winch, fix a broken
refrigerator, refuel, and swap out some crew members.
 |
| Forecast track for Bertha. Our approximate location is the red dot. |
Everyone is happy to have a bit of a break. We haven't had
much of a daily repeated sampling program as the weather can change quickly.
A lot of decisions need to be made on the fly, and the correct people
roused from their bunks in the middle of the night. This will give us a
good chance to recover and be back at it later in the week.
As always, the rest of the updates are under the "Research Cruise" label. Updates will continue, even while we are in port, so stay tuned!
More posts in this series:
Upcoming Cruise
Cruise Delays
Upcoming Cruise, Part II
Update #1
Update #2
Update #4
Update #5
Update #6
Update #7
Update #8
Update #9
More posts in this series:
Upcoming Cruise
Cruise Delays
Upcoming Cruise, Part II
Update #1
Update #2
Update #4
Update #5
Update #6
Update #7
Update #8
Update #9
