Response to US JGOFS Time-Series Oversight Committee Report that
was
submitted to the US JGOFS Steering Committee
Anthony H. Knap and Anthony F. Michaels
Bermuda Atlantic Time-series Station
Bermuda Biological Station for Research, Inc
St. Georges, Bermuda GEO1
David Karl et al
Hawaii Ocean Time-series
SOEST, University of Hawaii
Honolulu, Hawaii
The BATS and HOT PI's would like to thank the Time Series Oversight
group
for a thoughtful review. We have found these oversight committee
reviews
useful for both pointing out areas of potential improvement in
the present
program and for looking forward to the future, thus providing
a context for
future directions and providing areas of concentration of effort.
It is our
view that these two sites are providing valuable insights into
the
biogeochemical cycles in the open ocean and we are pleased that
the
oversight report acknowledges this. At the time of the discussion
of the
report we did not have an opportunity to see the draft so our
verbal
comments at the Steering Committee meeting in Hawaii are followed
by this
written response. In the Oversight report a few items were omitted
that
were part of the Time-series oversight meetings such as a discussion
of the
importance of optics in the programs as well as a need for meteorological
measurements to be taken and be made part of Core. Some of the
changes
recommended in the report have been implemented and these will
be noted. We
do feel that it would be beneficial to all that in future, the
Oversight
Committee report should be available to the PI's and their written
comment
be received prior to discussion of it in the full SC meeting.
This would
allow for discrepancies to be resolved prior to discussion.
In this note we will discuss our response to the recommendations
of the
Committee.
A. Core Measurements
p-4 A common manual was suggested and we agree that this would
help to
re-define what we mean by core activities and suggest where we
diverge in
our programs. Bermuda will take the lead in this as they did in
preparing
the JGOFS protocols manual.
2. Quality Assurance
p-5 At present the CTD and salinity measurements are fine according
to
the finding of the TSOC report and using DIC CRM's means that
both sites
have access to certified reference material. There was some concern
about
the different methods used for alkalinity
titration's but Andrew Dickson pointed out that it appeared that
the CRM
standards that were produced for carbon could work for alkalinity
as well.
p-6 Dissolved oxygen is carried out by different methods at both
sites.
HOT PIs have agreed to adopt and purchase a similar instrument
to that used
at BATS, funds permitting (cost of new instrumentation approximately
$12K).
p-6 BBSR will investigate the opportunity for the colorometric
pH
measurement as a core measurement however this will also require
more
funds.
p-7 In the section on pigments, the detailed discussion resulted
in the
conclusion that the impromptu BATS/HOT the intercomparison between
both
sites was poorly designed as the differences between both laboratories
results were suggested to arise from a storage problem. Both groups
will
continue to participate in community-wide intercomparison programs
and not
attempt to carry out one-off calibrations. It was also noted that
the BATS
pigment methods were originally designed by HOT personnel (Bidigare)
and it
would be worthwhile to re-evaluate the present BATS protocols.
It is also
important to make sure that well designed intercomparison exercises
are
available for community wide involvement in for many other analytes.
p-8 For the enumeration of bacterial cells, BATS will work with HOT to
determine the best methods for both sites, most likely by dual
laser flow
cytometry.
p-9-10 As always the issue of sediment trap discussions took a
great deal
of time and it was agreed that there be a real effort to resolve
this at
both sites. This will require funding outside of the present funding
for
the two programs. In the interim, BATS and HOT will
try and trade personnel and try to further quantify some of the
methodological difference.
p-10 BATS presently does a lot of PC/N measurements. We will continue
to
investigate sharing of samples between the two sites however there
are
limitations to this and without a certified reference material
errors can
occur through sample storage, filtration and other problems.
p-10 Regarding low level measurements, we are working at sharing
expertise between the two sites and both sites believe that valuable
insights are gained from such methods and BATS should find a way
to have
these measurements made. Presently, these are not core measurements
at both
sites.
p-10 BATS will add particulate P at the next funding cycle. We
agree
that the deep sea sediment trap collections should be seen as
a community
wide effort and part of core. Presently, these have been separately
funded
efforts at Bermuda (funds to Dueser and Conte, WHOI) and we hope
that over
time the collections can be moved into the core suite of measurements
and
the data from the existing deep trap at Bermuda entered in to
the BATS data
base.
B. Data Products and their distribution
p-11 Data are now ready to be released electronically from both
sites at
6-9 months after collection. The printed data reports are unwieldy
and are
taking the greatest time to produce. The past delays in data reporting
have
been due to the hard copy reporting, and at Hawaii, coordination
with the
reporting obligations of the HOT-WOCE program PI's.
p-12 Data units, Both groups will try to adopt the same data reporting
units and an analysis of discrepancies in units will be undertaken
during
the attempt to develop a common manual.
p-12 Knap and Karl will write the ancillary investigators.
C. Resolving Spatial Variability
p-13 Validation cruises are now part of the BATS data base. This
has
been addressed since the Oversight meeting in Bermuda. Presently
BATS does
two per year but this is being increased to 4 per year in 1998.
A continual
profiler will be part of a new facilities request to NSF at BATS.
Similar
validation cruises have recently begun at Hawaii.
p-14 We agree that regional process cruises around the time-series
sites
would be a great addition to the data base and put in greater
context the
measurements at the two sites to the greater ocean around them.
This was
added as part of the TS Oversight report as an important high
priority for
new funding.
p-14 At BATS and HOT there are links to the satellite programs
at both
sites as well as to the Optics program at BATS. We feel it is
crucial that
the existing optical programs be ratified as part of the core
measurement
suite as currently occurs with the process studies. This will
be the only
way to link the in situ biogeochemistry to the next generation
of ocean
color satellites.
Resolving Temporal Variability with Moored Arrays
p-15 The mooring programs at both sites are important and are
underfunded. The support of these programs have been put in the
funding for
the renewal proposal. Both PI's are doing whatever they can to
keep these
mooring programs alive until 1998.
p-16 Shiptime. Shiptime at Bermuda was reduced due to NSF budgetary
reasons however the renewal proposal is to increase this shiptime
to cover
the needs for the transect work. At Hawaii, discussion regarding
a suitable
platform are ongoing.
We also believe that we should have a joint technician meeting
and we
should try and get funding for such a sharing of personnel at
least every
two years. We also would like to add that we are trying to preserve
the
long term nature of these sites by continuing the dialog of BATS
and HOT
future in relation to LTER/CLIVAR