SBI Summer Cruise 2002: HLY-02-03-Final Cruise
Report (17 July to 26 August 2002) Edited by Lee Cooper, Chief Scientist (send
comments to lcooper1@utk.edu)
The
field phase of the Western Arctic Shelf-Basin Interactions (SBI) project
completed a successful scientific mission to the Arctic on the new USCGC Healy
icebreaker 17 July-26 August 2002. This was the second in a series of
interdisciplinary research cruises by the Healy in 2002 in support of the
Shelf-Basin Interactions project. The
goal of the SBI project is to investigate the production, transformation and
fate of carbon at the shelf-slope interface in the Arctic as a prelude to understanding
the impacts of environmental change in the Arctic. Forty-five stations were
occupied during this cruise, and a total of 39 scientists from nineteen
institutions in the United States, Bermuda, Canada, and the United Nations
Marine Environmental Laboratory (Monaco) participated in this interdisciplinary
scientific endeavor.
In
2002, the SBI project applied a broad array of physical, biogeochemical and
biological measurements, which are almost unprecedented in scope for the
Arctic. The new ship platform that we
used to accomplish this sampling is well suited to meeting the challenge of
modern multi-investigator, interdisciplinary research.
In
our sampling, we used a CTD/rosette system for collecting physical and
hydrochemical samples. Subsamples from multiple CTD/rosette casts were used for
primary production, chlorophyll content, nutrients, particulate carbon,
inorganic carbon, biomarkers, microzooplankton, and radioisotopes. Various nets
(vertical, bongo) were used to collect size fractions of micro-macro- and
meso-zooplankton for both population and experimental purposes. Benthic grabs
and cores were used to collect benthic fauna and sediment samples for
population, community structure, food web, chemistry and metabolism
studies. In-situ pumps were also used
to measure the activities of the particle-reactive radionuclide thorium-234.
Almost
every major planned scientific objective was met during this cruise. One of the
few exceptions was the inability to document the vertical distribution of some
zooplankton because of damage to a MOCNESS net system following deployment in
heavy ice. Also, during a high-wind event (up to 50 knots) in a portion of the
study area that was mostly open water, some sampling on the starboard side was
suspended because of the danger that fast-moving ice would impact the CTD. Even
under these difficult conditions, however, stern sampling operations continued
except for a brief safety-influenced interruption. Several challenges that had
arisen during the first SBI cruise in May-June, 2002, including the temperature
of flow-through incubator water were much alleviated by operational
improvements made by the engineering department of the ship.
The Captain,
officers and crew of the USCGC Healy are acknowledged for their professional
and helpful facilitation of the cruise goals. In particular, we express our
appreciation to Captain David Visneski, Operations Officer Joe Segalla,
Executive Officer Doug Russell, Engineering Officer Greg Stanclik, Chief Peter
Schaffner, DC2 Paul Thomas, DC3 Todd Gillick, and Master Chief Navigator George
Schwarz. We would not have been able to perform this research without the
skillful work of the marine science technician team, Glen Hendrickson (lead),
Sean Kuhn, Suzanne Scriven, Bridget Cullers, Michael Hamerski, and Josh Robinson),
as well as their science officer, Mike Woodrum. The Aviation Department, led by
Lt. Mike Platt also contributed significantly in transporting personnel,
samples, and equipment during the course of the cruise. In Nome and in Barrow,
Andy Heiberg of the University of Washington made himself indispensable to
meeting the logistical needs of the project as a whole. Also, in Barrow, we are
grateful for the assistance of the Barrow Arctic Sciences Consortium, including
Glenn Sheehan and Henry Gueco, for their liaison activities with the Aviation
Department, and for assisting us logistically in the transfer of personnel,
equipment and samples to and from the ship. This work was financially supported
by the U.S. National Science Foundation, the Office of Naval Research, and the
U.S. Coast Guard.
B. CRUISE SUMMARY AND OUTREACH EFFORTS
This cruise report
from the SBI Summer Cruise (HLY-02-03) covers the sampling period 17 July-26
August 2002 (UTC). Stations occupied included a transect in Bering Strait
(station preflix: BRS-) for limited water column measurements, shelf stations
north of Bering Strait (HV-), sampling in Alaska Coastal Water enroute to
Barrow (station prefix: ACW-), a transect in Barrow Canyon offshore to 3000 m
(station prefix: BC-), a deep basin-slope transect towards the Beaufort sea
coast (station prefix: EB-), and two additional shelf-to deep basin transects
on the east and west sides of Hanna Shoal in the Chukchi Sea (EHS- and WHS- ).
The following table and associated station maps are also available at the SBI
data web site, http://catalog.eol.ucar.edu/sbi_hly-02-03/.
In addition to the
research information available through the JOSS website, we are also
accommodating additional public outreach to explain our research program. A
broadcast crew from CBS News, a reporter from USA Today, and a reporter from
the Associated Press were aboard ship during our transit of Barrow Canyon.
Interviews were also provided by the chief scientist to a reporter for the Nome
Nugget prior to leaving port and to KBRW-AM/FM, a National Public Radio
affiliate in Barrow that broadcasts across the North Slope Borough. This
interview was undertaken using the INMARSAT telephone capabilities onboard the
ship. Several articles from USA Today are already available at: http://www.usatoday.com/weather/antarc/acoldsci.htm.
A news story was released at the end of August on the Associated Press wire and
has been picked by a number of newspapers, including the Baltimore Sun, Orlando
Sentinel, Fresno Bee, and Juneau Empire. CBS News broadcast three stories on
August 28, 29, 31, 2002 on their national evening news program, and are
planning a longer piece on the Sunday morning program during September 2002.
Some of the content of these news pieces is available at: http://www.cbsnews.com/stories/2002/08/29/eveningnews/main520240.shtml. The repeat visits of the Healy to Nome this summer
have also been well covered by the Nome Nugget, particularly in their June 20,
2002 and August 29, 2002 issues (http://www.nomenugget.com).
Finally, Betty
Carvellas, a Vermont high school teacher was aboard and provided daily updates
on research and ship operations, including spotlights on individual research
groups, explained in layperson’s terms. These daily updates are accessible
through the Teachers Experiencing the Antarctic and the Arctic web site (http://tea.rice.edu, specifically http://tea.rice.edu/tea_carvellasfrontpage.html).
While aboard the cruise, she
also served as a team member with the group investigating “Water/sediment
tracers, sediment metabolism and benthic community structure.” Outreach activities during the cruise
included a tour of the Healy for students from the Anvil City Science Academy
(a public magnet school in Nome) while the ship was anchored off Nome. Also
during the cruise INMARSAT telephone -aided Powerpoint presentations were made
of cruise activities to a district-wide teachers-in service at Essex High
School, and to a public forum at the Burnham Library, both in Colchester,
Vermont.
STATION SUMMARIES
|
STATION NO. |
DATE |
TIME(UTC) |
LATITUDE |
LONGITUDE |
TARGET |
DURATION |
|
HLY-02-03-001(BRS1)
|
07/18/02 |
03:10 |
65:39.86N |
168:12.72W |
30m |
0.4 hrs |
|
HLY-02-03-002(BRS5)
|
07/18/02 |
05:45 |
65:42.50N |
168:51.76W |
45m |
0.5 hrs |
|
HLY-02-03-003(BRS4)
|
07/18/02 |
07:17 |
65:41.86N |
168:43.84W |
45 m |
0.5 hrs |
|
HLY-02-03-004(BRS3)
|
07/18/02 |
09:08 |
65:40.87N |
168:34.34W |
45 m |
0.6 hrs |
|
HLY-02-03-005(BRS2)
|
07/18/02 |
10:57 |
65:40.21N |
168:25.37W |
45 m |
0.4 hrs |
|
HLY-02-03-006(HV1)
|
07/18/02 |
22:14 |
67:28.22N |
168:54.22W |
46 m |
6.9 hrs |
|
HLY-02-03-007
(ACW1) |
07/19/02 |
14:00 |
68:30.66N |
167:23.02W |
43 m |
7.2 hrs |
|
HLY-02-03-008
(ACW2) |
07/20/02 |
08:13 |
69:57.28N |
164:23.53W |
32 m |
3.4 hrs |
|
HLY-02-03-009
(productivity) |
07/20/02 |
16:14 |
70:27.88N |
163:05.70W |
- |
2.0 hrs |
|
HLY-02-03-010(BC1)
|
07/21/02 |
05:02 |
71:00.98N |
159:41.12W |
80 m |
5.2 hrs |
|
HLY-02-03-011
(productivity) |
07/21/02 |
16:15 |
71:02.63N |
159:35.41W |
- |
1.9 hrs |
|
HLY-02-03-012(BC2)
|
07/21/02 |
20:02 |
71:22.77N |
157:45.09W |
120 m |
11.4 hrs |
|
HLY-02-03-013(BC3)
|
07/22/02 |
13:06 |
71:36.24N |
156:12.49W |
200 m |
21.1 hrs |
|
HLY-02-03-014(BC4)
|
07/23/02 |
15:46 |
71:49.82N |
155:01.35W |
500 m |
21.7 hrs |
|
HLY-02-03-015(BC5)
|
07/24/02 |
15:45 |
71:59.66N |
154:42.55W |
1000 m |
6.7 hrs |
|
HLY-02-03-016(BC6)
|
07/25/02 |
08:56 |
72:12.33N |
154:05.56W |
2000 m |
48.6 hrs |
|
HLY-02-03-017(BC7)
|
07/27/02 |
13:52 |
72:30.67N |
153:17.25W |
3000 m |
27.8 hrs |
|
HLY-02-03-018(EB7)
|
07/29/02 |
00:08 |
72:19.33N |
151:59.07W |
3000 m |
35.6 hrs |
|
07/30/02 |
12:50 |
72:12.00N |
151:59.70W |
- |
- |
|
|
07/30/02 |
14:21 |
72:06.30N |
152:02.00W |
- |
- |
|
|
07/30/02 |
15:42 |
72:00.80N |
152:04.60W |
- |
- |
|
|
07/30/02 |
15:52 |
72:00.80N |
152:04.60W |
- |
- |
|
|
HLY-02-03-019(EB6)
|
07/30/02 |
18:58 |
71:54.52N |
151:58.29W |
2000 m |
27 hrs |
|
08/01/02 |
00:37 |
71:49.81N |
152:12.01W |
- |
- |
|
|
08/01/02 |
01:51 |
71:45.26N |
152:16.92W |
- |
- |
|
|
HLY-02-03-020(EB5)
|
08/01/02 |
03:45 |
71:41.78N |
152:18.65W |
1000 m |
27.7 hrs |
|
HLY-02-03-021(EB4)
|
08/02/02 |
08:45 |
71:38.89N |
152:24.50W |
500 m |
22.3 hrs |
|
08/03/02 |
07:50 |
71:35.56N |
152:24.63W |
- |
- |
|
|
HLY-02-03-022(EB3)
|
08/03/02 |
08:35 |
71:33.73N |
152:24.42W |
200 m |
15.6 hrs |
|
08/04/02 |
03:00 |
71:29.76N |
152:28.52W |
- |
- |
|
|
HLY-02-03-023(EB2)
|
08/04/02 |
03:54 |
71:27.48N |
152:33.38W |
100 m |
8.7 hrs |
|
08/04/02 |
14:11 |
71:22.44N |
152:35.27W |
- |
- |
|
|
HLY-02-03-024(EB1)
|
08/04/02 |
15:36 |
71:17.97N |
152:38.75W |
50 m |
9.1 hrs |
|
HLY-02-03-025(EHS1)
|
08/06/02 |
09:12 |
72:14.18N |
159:19.69W |
50 m |
2.7 hrs |
|
HLY-02-03-XCTD_10
(EHS2) |
08/06/02 |
13:34 |
72:22.28N |
158:58.01W |
- |
- |
|
HLY-02-03-XCTD_11
(EHS3) |
08/06/02 |
14:38 |
72:28.50N |
158:48.73W |
- |
- |
|
HLY-02-03-026(EHS4)
|
08/06/02 |
16:23 |
72:38.76N |
158:36.00W |
100 m |
16.1 hrs |
|
08/07/02 |
09:22 |
72:38.69N |
158:34.05W |
- |
- |
|
|
08/07/02 |
09:55 |
72:41.00N |
158:29.90W |
- |
- |
|
|
HLY-02-03-027(EHS5)
|
08/07/02 |
10:33 |
72:42.13N |
158:25.96W |
200 m |
16.3 hrs |
|
08/08/02 |
06:32 |
72:46.76N |
158:22.13W |
- |
- |
|
|
08/08/02 |
07:04 |
72:49.37N |
158:19.19W |
- |
- |
|
|
HLY-02-03-028(EHS6)
|
08/08/02 |
08:41 |
72:50.25N |
158:15.11W |
500 m |
22.6 hrs |
|
HLY-02-03-029(EHS7)
|
08/09/02 |
11:51 |
72:52.87N |
158:12.32W |
1000 m |
26.5 hrs |
|
08/10/02 |
12:04 |
72:57.23N |
158:05.38W |
- |
- |
|
|
HLY-02-03-XCTD_17
(EHS8) |
08/10/02 |
12:35 |
72:59.82N |
158:01.95W |
- |
- |
|
08/10/02 |
13:05 |
73:02.27N |
157:57.08W |
- |
- |
|
|
HLY-02-03-030(EHS9)
|
08/10/02 |
13:52 |
73:04.64N |
157:53.85W |
2000 m |
28.7 hrs |
|
08/11/02 |
20:18 |
73:11.89N |
157:41.73W |
- |
- |
|
|
HLY-02-03-XCTD_20
(EHS10) |
08/11/02 |
21:27 |
73:17.67N |
157:33.33W |
- |
- |
|
HLY-02-03-031
(EHS11) |
08/11/02 |
23:24 |
73:25.09N |
157:21.74W |
3000 m |
24.8 hrs |
|
HLY-02-03-032
(WHS7) |
08/13/02 |
04:47 |
73:42.47N |
159:04.98W |
3000 m |
20.1 hrs |
|
HLY-02-03-033
(WHS6) |
08/14/02 |
03:44 |
73:29.92N |
159:33.47W |
2000 m |
22.1 hrs |
|
08/15/02 |
05:34 |
73:25.82N |
159:43.13W |
- |
- |
|
|
08/15/02 |
07:00 |
73:21.06N |
159:53.09W |
- |
- |
|
|
HLY-02-03-034
(WHS5) |
08/15/02 |
17:30 |
73:17.69N |
160:14.40W |
1000 m |
16.5 hrs |
|
HLY-02-03-035
(WHS4) |
08/16/02 |
11:59 |
73:12.78N |
160:09.53W |
500 m |
15.4 hrs |
|
HLY-02-03-036
(WHS5) |
08/17/02 |
05:24 |
73:16.49N |
160:06.59W |
1000 m |
0.6 hrs |
|
08/17/02 |
08:20 |
73:09.95N |
160:20.14W |
- |
- |
|
|
HLY-02-03-037
(WHS3) |
08/17/02 |
11:15 |
73:04.30N |
160:20.90W |
200 m |
9.4 hrs |
|
HLY-02-03-038
(WHS2) |
08/17/02 |
21:55 |
72:59.29N |
160:38.52W |
100 m |
13.6 hrs |
|
HLY-02-03-039
(WHS1) |
08/18/02 |
15:50 |
72:48.21N |
161:05.29W |
50 m |
10.7 hrs |
|
HLY-02-03-040(HC1)
|
08/19/02 |
04:38 |
72:54.78N |
161:56.79W |
50 m |
0.6 hrs |
|
HLY-02-03-041(HC2)
|
08/19/02 |
07:42 |
73:05.82N |
162:52.49W |
150 m |
5.0 hrs |
|
HLY-02-03-042(HC3)
|
08/19/02 |
15:57 |
73:19.27N |
164:28.19W |
75 m |
4.3 hrs |
|
HLY-02-03-043(HV4)
|
08/19/02 |
22:55 |
73:37.85N |
165:23.57W |
90 m |
7.2 hrs |
|
HLY-02-03-044(HV3)
|
08/20/02 |
08:50 |
73:20.46N |
165:30.25W |
70 m |
14.5 hrs |
|
HLY-02-03-045(HV2)
|
08/21/02 |
12:13 |
70:40.95N |
166:29.70W |
50 m |
11.4 hrs |
C. INDIVIDUAL PROJECT PROGRESS REPORTS
1. Hydrographic Measurements Team; Lou Codispoti
lead (on board); Jim Swift, lead PI
Other team members: Kristin
Sanborn, Dean Stockwell, Robert Palomares, Doug Masten, Emily Cooper, Carny
Cheng
John Gunn (ADCP information
appended below)
Observations:
On
this leg (Healy 02-03, 15 July – 26 August 2002), we completed 159 CTD casts
and collected underway acoustic Doppler current profiler (ADCP) data. We have also analyzed 300 frozen nutrient
samples from the Bering Sea collected during Healy cruise 02-02. All data have been edited and posted on the
JOSS web site, and we have plotted the data from our sections in Bering Strait,
Barrow Canyon, East Barrow Canyon, East Hanna Shoal, West Hanna Shoal, and a
final cross shelf section. Our
observations include continuous vertical profiles of temperature, salinity,
dissolved oxygen, fluorometric “chlorophyll”, light transmission, Haardt
fluorescence (an index of colored organic matter), and photosynthetically
available radiation (PAR). Discrete sea
water samples collected from our 30 liter rosette bottles have been analyzed
for salinity, dissolved oxygen, ammonium, nitrate, nitrite, urea, phosphate,
silicate, chlorophyll and phaeophytin concentrations.
Results:
In
contrast with our May-June cruise (Healy 02-01) when several stations had
surface nitrate concentrations in excess of 10 micromolar, surface nutrient
concentrations in the Bering Strait inflow waters were low. In fact, nitrate was depleted or nearly so
in the surface waters of all stations taken during Healy 02-03. During Healy 02-01, nitrate depletion was
observed only in surface waters at our most offshore stations.
In
the Bering Strait section taken during this leg, the highest fluorometric
chlorophyll values were found over the bottom not at the surface, suggesting
post-bloom conditions. In our suite of Beaufort Sea stations, subsurface
chlorophyll maxima, dissolved oxygen supersaturations, and light transmission
minima were common suggesting a downward penetration of the depth of maximum
phytoplankton growth. This condition
was made possible by the extreme stratification of the photic zone arising from
melting ice, light winds and suppression of waves by the ice-cover. At some stations, measured surface
salinities fell below 15, and we observed density currents in the upper few cm
as the CTD/rosette was lowered into the water column. During these times when winds were weak and melting ice was
present, large differences occurred between the CTD salinity and bottle
salinity over a distance of only ~ 1m, and it is possible that the surface sea
water sample was stratified within the Niskin bottle!
As
was the case during Healy 02-01, nutrient distributions provided abundant
evidence for shelf-basin interactions.
Plumes of elevated silicate, phosphate, ammonium, urea and nitrite and
N** (a proxy for the effects of nitrogen fixation vs denitrification history)
concentrations extended from the shelf into deeper offshore waters at depths of
~50-200 meters on all cross-shelf sections except for the East Barrow Canyon
Section, where the situation appeared to be a bit more complicated. Here, only the urea distribution showed a
plume that seemed to have a clear origin on the shelf. Maxima in other variables had a tendency to
peak offshore and to intersect the shelf break instead of the more shallow
portions of the shelf. Our initial
impression is that, in the East Barrow Canyon section, the silicate, phosphate,
etc. maxima were under the influence of advection from the west and possibly
complicated by the presence of an eddy.
A Haardt fluorescence maximum that appears to have an offshore origin
interacted with the plumes originating on the shelf during both Healy legs, and
it will be interesting to use the offshore tracer provided by Haardt
fluorescence and the data on the plumes emanating from the shelf to gain
insight into the interactions of shelf and offshore waters.
A
notable difference between Healy 02-01 and Healy 02-03 (when we compared data from the same
sections) was an increase of 5 to 10 micromolar in maximum silicate
concentrations in the plume originating over the shelf. This observation suggests fairly rapid
settling and re-mineralization of diatoms produced by the spring bloom over the
shelf. Indeed, this change may have
begun during Healy 02-01 since our last section had the highest silicate
concentrations in this plume, and light transmission data suggested an ongoing
bloom producing rapidly sinking particles (presumably diatoms).
Analysis:
Our
first cruise (Healy 02-01) during May-June appeared to begin early in the
growing season with nutrient depletion evident only at our deepest (most
offshore) stations in the Chukchi Sea. By the end of this leg, we began to see
the beginning of a bloom over the shelf.
It may also be worth noting that during Healy 02-01, we saw an abundance
of ice-algae suggesting that the ice-algae bloom had peaked. By the time of
Healy 02-03, the ice algae and surface layer blooms seemed to have ended, but
subsurface chlorophyll maxima and associated oxygen supersaturations and light
transmission minima suggested healthy rates of production deeper in the photic
zone.
Consistent
with the ending of the ice algae and surface layer blooms, silicate
concentrations in the bottom waters over the shelf and in the high-silicate
bloom extending offshore increased as the presumable consequence of the sinking
and re-mineralization of diatoms. What
was somewhat surprising to us was the rapidity of the increase in silicate
concentrations between legs.
Despite
a vigorous low pressure system that came by towards the end of the cruise with
some wind gusts exceeding 40 knots, the stratification of the waters that we
encountered was so strong that we observed no significant interruption of the
surface nitrate depletion.
ADCP
Data Collection:
The
USCGC Healy operates two Acoustic Doppler Current Profilers (ADCPs) while
underway, a broad band 150 kHz (BB150) and an ocean surveyor 75 kHz
(OS75). The higher frequency BB150 has
finer vertical resolution where the lower frequency OS75 has a greater range. Various environmental influences can affect
the performance of these instruments. During this cruise the BB150 had a
maximum range of 200-250m and the OS75 had a range reaching 400-450m. Data was collected along the entire cruise
track, including two transects crossing the flow northward from Bering Strait,
one at Point Hope and the other in the Bering Strait itself. The instruments generally collected data
with few problems.
Data
quality was affected most severely while underway in ice. This is common with all acoustic equipment
under these conditions and is not considered exceptional. The Summer SBI cruise
did not encounter excessive amounts of ice and it generally only posed a
problem during data collection in areas near Barrow and to the east. In addition, the shallow seas on the Chukchi
Shelf limit the access of the ADCPs because of the deep draft of the USCGC
Healy (8.4m) and the data blanking that is preset with these instruments,
generally 6-10m. The first bin of
quality data can be as deep as 25-35 meters that limits data return with
vertical bin sizes of 6-10m and a bottom depth of 40-50 meters, at times. These limitations are consistent with the
design of these instruments that perform best in deep waters and are not
considered unreasonable in this application.
A
preliminary data processing methodology was developed during the spring cruise
(HY0201) and was implemented during HY0203 to produce velocity data that have
undergone preliminary calibration and data quality checks. The results should be adequate for
determining the overall velocity structure during the cruise. The sound velocimeter in the transducer
well was operational during this cruise and will provide the ability to make
further refinements in the data quality during post-cruise processing.
The ADCP velocity data distributed at the end of the
cruise have been averaged into half-hour by 10 meter vertical bins from each
instrument. These data are contained in
two large ASCII data files, HY0203_BB150_ADCP_Vel.dat and HY0203_OS75_ADCP_Vel.dat,
in which the velocity profiles are listed, together with the date, time and
position, for each time interval. Data
bins where the velocity data did not pass the preliminary editing process are
indicated by “99999”. Some of these
data may be restored during subsequent processing. These data are also presented in color contour plots of eastward
and northward current components verses time in the files:
hy0203_bb150_veltime_22aug.jpg and hy0203_os75_veltime_22aug.jpg, respectively.
In
addition to these basic data products, plots of velocity contours are also
presented for the Barrow Canyon (BC), East barrow Canyon (EB), and West and
East Hanna Shoals (WHS and EHS) sections.
For these plots, the data were averaged into 5 km radial segments from
the beginning of each section. The
standard deviations of the eastward and northward binned velocities are also
presented in separate plots for each ADCP.
The velocity contour plots for these transects are presented in:
OS75
hy0203_velsect_os75_bc_sdev.jpg
hy0203_velsect_os75_bc_vel.jpg
hy0203_velsect_os75_eb_sdev.jpg
hy0203_velsect_os75_eb_vel.jpg
hy0203_velsect_os75_ehs_sdev.jpg
hy0203_velsect_os75_ehs_vel.jpg
hy0203_velsect_os75_whs_sdev.jpg
hy0203_velsect_os75_whs_vel.jpg
BB150
hy0203_velsect_bb150_bc_sdev.jpg
hy0203_velsect_bb150_bc_vel.jpg
hy0203_velsect_bb150_eb_sdev.jpg
hy0203_velsect_bb150_eb_vel.jpg
hy0203_velsect_bb150_ehs_sdev.jpg
hy0203_velsect_bb150_ehs_vel.jpg
hy0203_velsect_bb150_whs_sdev.jpg
hy0203_velsect_bb150_whs_vel.jpg
All
data files mentioned are available on the cruise CD.
2. Primary production,
bio-optics, and remote sensing of ocean color; Dave Ruble, lead (on-board),
Glenn Cota, PI Other team members:
Zhi-Ping Mei and Xiaoju Pan
On
this cruise our group conducted three areas of investigation including primary
production, bio-optics, and satellite remote sensing. Experimental observations have included primary production as
well as nitrogen uptake. Urea
concentrations remained low, but two experiments were run to evaluate
utilization. Isotope dilution
experiments (IDE) have been done twice.
Phytoplankton pigment (HPLC) and cell count samples have been collected
from the surface and the bottom of the euphotic zone or subsurface chlorophyll
maximum. The samples and data will be
analyzed at a shore-based laboratory.
The
flow-thru seawater system with ballast water for deck incubations performed
well. Close monitoring, frequent refills, and total volume exchanges being a
necessity in maintaining the near ambient temperatures. Short term in-situ experiments were
conducted at four stations for comparison with the simulated in situ deck
incubations.
Experimental Observations
|
Date |
SBI Stn |
Secchi Depth (m) |
HPLC |
Cell
counts |
Primary Production |
13CO3 |
15NO3 |
15NH4 |
15N-Urea |
|
2002-07-19 |
7 |
24 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-07-20 |
9 |
16 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-07-21 |
11 |
5 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-07-22 |
13 |
3 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-07-23 |
14 |
8 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-07-24 |
15 |
9.5 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-07-25 |
16 |
9.5 |
+ |
+ |
+ |
+ |
+ |
+IDE |
|
|
2002-07-27 |
17 |
24 |
+ |
+ |
+In situ (S) |
+ |
+ |
+ |
+ |
|
2002-07-29 |
18 |
16 |
+ |
+ |
+In situ (S) * |
+ |
+ |
+ |
+ |
|
2002-07-31 |
19 |
12 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-01 |
20 |
8 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-02 |
21 |
10 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-03 |
22 |
7 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-04 |
24 |
8 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-06 |
26 |
19 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-07 |
27 |
16 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-08 |
28 |
20 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-09 |
29 |
18 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-10 |
30 |
20 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-12 |
31 |
21 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-13 |
32 |
34 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-14 |
21 |
21 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-17 |
37 |
15 |
+ |
+ |
+ |
+ |
+ |
+IDE |
|
|
2002-08-18 |
39 |
16 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-19 |
42 |
21 |
+ |
+ |
+ |
+ |
+ |
+ |
|
|
2002-08-20 |
44 |
21 |
+ |
+ |
+In situ (S) |
+ |
+ |
+ |
|
|
2002-08-21 |
45 |
12 |
+ |
+ |
+In situ (S) |
+ |
+ |
+ |
|
*
Short term in situ not recovered.
Optical
observations have included surface optics (SO), sun photometry (Sun), passive
optical (PO) profiles, and active optical (AO) profiles at daytime
stations. One SO and a few Sun
photometry observations have been made between stations or during suitable
conditions at a station. These data
will be invaluable for refining high latitude bio-optical algorithms. Discrete water samples from the production
cast were taken to measure light absorption spectrum (280 to 850 nm) for
phytoplankton pigments, detritus, and soluble material.
Optical Observations
|
|
|
|
|
SfcOpt |
Sun |
PassOpt |
ActOpt |
ActOpt |
|
ORCA Station
# |
SBI
Station # |
Secchi
depth |
Water Depth |
SAS |
Micro Tops |
Pro/Ref |
AC9 |
HS6 |
|
200207181 |
06 HV1 |
- |
45 |
+ |
+ |
+ |
+ |
+ |
|
200207191 |
07 ACW1 |
24 |
45 |
+ |
+ |
+ |
+ |
+ |
|
200207201 |
09 (prod) |
16 |
35 |
+ |
+ |
+ |
+ |
+ |
|
200207202 |
underway |
- |
42 |
+ |
+ |
|
|
|
|
200207211 |
11 (prod) |
5 |
115 |
+ |
|
|
+ |
+ |
|
200207221 |
13 BC3 |
3 |
172 |
|
|
+ |
+ |
+ |
|
200207231 |
14 BC4 |
8 |
283 |
+ |
|
+ |
+ |
+ |
|
200207241 |
15 BC5 |
9.5 |
975 |
|
|
+ |
+ |
+ |
|
200207251 |
16 BC6 |
9.5 |
1310 |
|
|
|
+ |
+ |
|
200207271 |
17 BC7 |
24 |
3159 |
+ |
+ |
+ |
+ |
+ |
|
200207272 |
17 BC7 |
- |
3121 |
+ |
+ |
|
|
|
|
200207291 |
18 EB7 |
16 |
2862 |
|
+ |
+ |
+ |
+ |
|
200207301 |
19 EB6 |
>9 |
2202 |
|
+ |
+ |
+ |
+ |
|
200207311 |
19 EB6 |
12 |
2100 |
|
+ |
+ |
+ |
+ |
|
200208011 |
20 EB5 |
8 |
1004 |
|
|
+ |
+ |
+ |
|
200208021 |
21 EB4 |
10 |
808 |
|
|
+ |
+ |
+ |
|
200208031 |
22 EB3 |
7 |
165 |
+ |
|
+ |
+ |
+ |
|
200208041 |
24 EB1 |
8 |
51 |
+ |
|
+ |
|
|
|
200208051 |
underway |
- |
84 |
|
+ |
- |
+ |
+ |
|
200208061 |
25 EHS4 |
19 |
161 |
+ |
|
+ |
+ |
+ |
|
200208071 |
27 EHS5 |
16 |
225 |
+ |
|
+ |
+ |
+ |
|
200208081 |
28 EHS6 |
20 |
455 |
+ |
|
+ |
+ |
+ |
|
200208091 |
29 EHS7 |
18 |
1198 |
+ |
|
+ |
+ |
+ |
|
200208101 |
30 EHS9 |
20 |
1882 |
|
+ |
+ |
+ |
+ |
|
200208121 |
31 EHS11 |
21 |
3191 |
|
|
+ |
+ |
+ |
|
200208131 |
32 WHS7 |
34 |
2835 |
|
|
+ |
+ |
+ |
|
200208141 |
33 WHS6 |
21 |
2140 |
+ |
|
+ |
+ |
+ |
|
200208171 |
37 WHS3 |
16 |
187 |
+ |
|
+ |
+ |
+ |
|
200208181 |
39 WHS1 |
16 |
55 |
+ |
|
+ |
+ |
+ |
|
200208191 |
42 HC3 |
21 |
75 |
+ |
|
+ |
+ |
+ |
|
200208201 |
44 HV3 |
21 |
73 |
+ |
|
+ |
+ |
+ |
|
200208211 |
45 HV2 |
12 |
40 |
+ |
|
+ |
+ |
+ |
3. Carbon and nitrogen
cycling group; Cynthia Moore, Paul Lethaby, and Christine Pequignet (on-board
team)
Dennis Hansell and Nick
Bates, PIs
We
have sampled DIC and Total Alkalinity (TA) at 42 stations for all the service
casts (shallow and deep) + 11 productivity casts [stations 11, 14, 15, 16, 17,
18, 19, 20, 24, 39 (DIC only) and 42 (DIC only)]. That is a total of 514 samples for DIC and 502 for TA. We sampled productivity casts following
requests by Zhi-Ping Mei.
Unfortunately, we were unable to sample all productivity casts as we did
not originally plan for sampling them and would have ran out of bottles for our
core sampling efforts if we had done so.
For
DOC, POC/PON, and TDN, we have sampled at 40 stations, including all “service”
casts (total of 53). That is a total of
454 samples for DOC and TDN and 410 for POC/PON.
N.B.:
For sample at a depth>500m, the TDN and DOC samples are not filtered, so the
measurements are TN and TOC.
All
samples were preserved, for analysis in the lab. An extra sample for TN was taken and was ran on the ship by Cindy
Moore. DOC and TDN samples are going to
Miami from Nome to be analyzed at the U. of Miami. The DIC, TA and POC/PON samples will be shipped from Seattle to
Bermuda to be analyzed at the Bermuda Biological Station for Research.
Overall
the cruise went well for our group, we were able to reach the goals we had set
and did not have any problems doing so.
Dave Kadko, PI
105
large volume seawater samples (180-235 L) were collected from 45 Shelf-Basin Interaction
(SBI) stations. Preliminary shipboard
analyses of 224Ra have been completed for every sample and final 224Ra
and 228Th analyses have been completed for approximately
25% of all samples. Measurements were
made using a radium delayed coincidence counter, purchased specifically for the
SBI project. Analyzed samples have been
sealed in petri dishes where, on land, 228Ra and 226Ra
isotopes will be determined using gamma ray spectrometry.
In
addition to radioisotope samples, 23 expendable conductivity-temperature-depth
(XCTD) probes were successfully deployed along the East Barrow, East Hanna
Shoal, and West Hanna Shoal transects.
Geostrophic current velocities calculated using XCTD and CTD data will
be used to augment 224Ra results. Data from these probes have been
made available to all scientists via the Joint Office of Science Support (JOSS)
website.
A
30-minute science lecture for both crew and scientists highlighting preliminary
results was presented on August 5, 2002.
Dave Kirchman, PI
The
microbiology group sampled coincidently with the productivity cast following
the routine established on the Spring SBI leg HLY-02-01. Measurements include bacterial abundance,
production and species composition which are typically made at 7 depths,
including 4 in the photic zone and 3 below the 1% light depth down to 200 m or
the bottom of the water column. Core
bacterial measurements were made at every productivity station through the Bering
Strait and on the Barrow Canyon and East Barrow Transects (16 stations).
In
addition to the core bacterial measurements, including bacterial abundance and
production, we are also measuring rates of community oxygen consumption and
production in the water column. Three
depths in the photic zone and two below the 1% light depth are assayed for
oxygen consumption in dark bottle incubations.
In addition, net oxygen production in photic zone samples are measured
at simulated in situ irradiance in the flow through incubators on the foredeck
in collaboration with the primary productivity group.
Twenty-three
productivity stations on four transects were sampled by the microbiology group.
Rates of community oxygen consumption were low with approximately one third of
the assays conducted over the four transects yielding rates above our
analytical detection limit of 25 nM L-1 h-1. As we
expected, rates of oxygen consumption were higher on the shelf than in the
basin. In contrast, it was surprising that dark incubations yielded net oxygen
production. We observed dark oxygen
production in ten experiments. Our
initial hypothesis that oxygen was being released from photochemical end products
may be only part of the answer since this phenomenon was not restricted to the
surface waters. In a few instances it
was highest at the 1% light depth. It
appears that dark oxygen production deserves consideration in the oxygen budget
of the Arctic shelf and basin system.
We
solved difficulties with the Winkler oxygen measurements encountered on the
spring cruise during the transit through the Bering Strait. Availability of 24-h Internet access
(available during the early stage of the cruise) played an important role in
facilitating troubleshooting. Rapid
email turnaround and access to information on the World Wide Web were essential
for our success.
Filling
as many as 60 oxygen bottles from the rosette without disrupting the other
sampling is a logistical challenge that has been met with a highly efficient
and equitable sampling scheme organized by Kristin Sanborn of the hydrographic
measurements group.
Four
samples for bacterial genetic analysis were collected with two obtained from
deep water (~1500 m) and two from 10 m through this ships running seawater
system.
Ron Benner and Roger Harvey,
PIs
The
table below lists the samples that were collected for characterization of
dissolved organic matter. In addition to these samples, samples of dissolved
and particulate matter were collected during a sampling trip to the Kokolik
River. These river samples will provide
valuable information on the composition of terrestrially-derived material
entering Alaska coastal waters.
A
photo-oxidation experiment was conducted with Ikpikpuk river water from the
HLY02-01 cruise to study the influence of sunlight on terrigenous material
entering the coastal waters.
The
flash fluorometer mounted on the rosette/CTD package monitoring emission
wavelengths that are characteristic of colored DOM (CDOM), which in the study
region is predominately derived from the terrestrial environment, acquired data
during every CTD cast. The fluorometer
will be calibrated using the concentrations of dissolved lignin in water
samples collected during this and the previous cruise. These data will provide information on the
concentrations and sources
HLY-02-03
- Karl Kaiser Sample Log (July 13, 2002 to August 26, 2002).
Particles, Ice Algae, and Sediments collected for organic
biomarker analysis
|
Station Number |
Station Code |
Date |
Time |
Cast |
Depths (m) |
Feature |
Type |
Volume Filtered (mL) |
Comments |
|
1 |
BRS-1 |
17-Jul-02 |
19:30 |
1 |
15 |
n/a |
PC/PN |
1000 |
|
|
|
|
|
|
|
15 |
n/a |
GF/F |
7000 |
|
|
2 |
BRS-2 |
17-Jul-02 |
22:30 |
1 |
15 |
n/a |
PC/PN |
400 |
|
|
|
|
|
|
|
15 |
n/a |
GF/F |
5000 |
|
|
6 |
HV-1 |
18-Jul-02 |
22:00 |
2 |
20 |
n/a |
PC/PN |
150 |
|
|
|
|
|
|
|
20 |
n/a |
PC/PN |
250 |
|
|
|
|
|
|
|
20 |
N/a |
GF/F |
1000 |
|
|
|
|
|
|
|
20 |
N/a |
GF/F |
1000 |
|
|
|
|
|
|
|
35 |
N/a |
PC/PN |
100 |
|
|
|
|
|
|
|
35 |
N/a |
PC/PN |
110 |
|
|
|
|
|
|
|
35 |
N/a |
GF/F |
1000 |
|
|
|
|
|
|
|
35 |
N/a |
GF/F |
1000 |
|
|
7 |
ACW-1 |
19-Jul-02 |
9:45 |
2 |
10 |