23-24 March 2000
Baltimore, MD
PARTICIPANTS
SBI SSC: Jackie Grebmeier (Chair), Knut Aagaard, Eddy Carmack, Lou Codispoti, Dennis Darby, Ken Dunton, Igor Melnikov, Sue Moore, Toshi Takizawa, Pat Wheeler, John J. Walsh, Paul Wassman, Terry Whitledge (co-Chair); (absent: Marty Bergmann
NSF management: Mike Ledbetter, John Christensen
Support staff: Holly Kelly
23 MARCH 2000-MORNING SESSION
Part 1 of the morning session was devoted to open dialogue among the SSC, led by Jackie Grebmeier. The discussion covered topics such as identifying proposed study areas and the transect lines, what part of the year could the ship(s) realistically reach these areas and what should be the core measurements.
Knut outlined the physical aspects of the study region with the statement that there are really three different shelves. The Chukchi Shelf, the US Beaufort Shelf and the Canadian Shelf. Mike Ledbetter asked which will most likely be affected by global change, which is the focal point of SBI. Most participants are more familiar with the Chukchi Shelf and feel that this region should be the center of the study area. However, both Ken Dunton and Eddy Carmack had opinions about the importance of the Beaufort Shelf. Eddy commented that to really measure change one needs to compare two different areas. The Chukchi Shelf is governed more by a through-flow system (bottom-up = nutrients; top-down = zooplankton), whereas the Beaufort, especially around the Mackenzie River, is an upwelling system. He continued with the comment that the comparison of change is not wide shelf vs. narrow shelf, but through-flow vs. upwelling. He said the US should request that Canada put forth a program of its own that is similar to SBI.
Jackie had a general map of the SBI study region and several boxes and "pipelines" for transects were drawn and discussed. Mike reminded the group again that SBI is only one small part of future Arctic research and that the group should not feel compelled to survey or do time series in the entire Arctic. Several people supported the idea that new biological studies are needed at the shelf-slope boundary to examine the transformation of biological products and their transport to the interior. Knut stated that we need to identify pivotal places and concentrate on the ice-edge for understanding advective features along the shelf-basin boundary. Others said that we need to look at the fate of carbon, so we need to look at the shelf-slope boundary.
Several questions were raised about the notion of time-series studies. How are they to be defined? Do they not come after knowing the basics? Are they necessary to drive an understanding for transport? Will mooring data circumvent the need for time-series studies? Moorings can elicit distributional data, but not flux data, which require process studies. It was agreed that there should be a list of core measurements with quality control aspects and these should be well articulated. The moorings should definitely have biological sensors on them, since biology is a critical component of the SBI program.
Part II of the morning session began with Igor sharing ice maps and the suggestion that perhaps an ice camp(s) could be set up because ships can't get up early enough in the spring to catch the phytoplankton bloom. Mike asked what can be learned from ice camps that moorings can't do and cautioned that ice camps need to be very strongly justified to set up. In the long run, it was concluded that an ice camp could be set up one time in 2004.
John Christensen asked about whether there was a need to have time-series productivity studies to answer shelf-slope carbon exchange? Lou asked if we need to know the detail on how new productivity occurred or do we need more detail about the fate of organic matter? The discussion went on for several minutes about the need for time series measurements and the pros and cons for all aspects of that topic. Finally, it was concluded that we do not need to do a productivity time-series study at one site. Basically, because the nutrients are consumed by the time they make it to the shelf-break, the question of how the ice at the shelf-break affects the global productivity is less important. Terry indicated that the rates of productivity are not changing that much, because the driving force is the biomass (there is a strong correlation between productivity and chlorophyll). Lou stated that the term "seasonal cycles" could be substituted for time-series studies.
By the end of the morning, the SSC directed Jackie to take the lead authority, to organize working groups within the SSC, and make final decisions to move the program forward.
23 March 2000-afternoon session
Part I & II of the Thursday afternoon session were devoted solely to the discussion of goals and objectives of the SBI program. First off, Paul wrote out four main goals, which ultimately saw goals three and four rolled into one statement. Upon obtaining the three goals, the group next tried to fit every objective written in the draft Phase II implementation plan into one of these three principal goals. That evening Ken, Sue and Pat reformulated a modified version of the goals and objectives to have ready for further analysis on the morning of the 24th. These three stated goals (related to Figure 1) and 9 major objectives cover all three disciplines and will be put in the implementation plan
In order to under shelf-basin interactions, the project investigate the:
1) Exchange of water and bioactive elements through the Bering Strait region (INPUT);
2) Seasonal and spatial variability of biogenic matter recycling in the shelf-slope area (WITHIN THE STUDY BOX); and
3) Exchange across the shelf/slope to the Canadian Basin (OUTPUT).
The 9 study objectives within these three goals include:
· The role of physical processes (eg. plumes, frontal instabilities, eddies, water mass movements, upwelling, etc.) in the transport of biogenic matter and tracers into the basin interior, including the relative importance and rates of these circulations in cross shelf exchange
· Identification of the key physical shelf and/or slope processes that are correlated with localized concentrations of benthic and pelagic biota that are preserved both temporally and spatially that potentially reflect long-term circulation anomolies.
· The role of circulation in determining the spatial variability in the remineralization of organic matter in the water column and benthos
· Sea ice as an advective agent for the transport of biota and organic matter in relation to the physical mechanisms that determine the intrusion depth of these shelf products across the shelf and slope.
· The seasonal and inter-annual variability of primary production in relation to the factors regulating the formation and maintenance of the Arctic Ocean halocline and mixed layer
· Spatial and temporal scales of ice algal and water column productivity and the spatial distribution of higher trophic organisms in relation to ice cover and the processes controlling stratification along the shelf and slope
· The spatial variations in the biomass and diversity of primary and secondary consumers, in both the water column and benthos, with respect to cross shelf circulation processes
· The relative importance of top-down vs bottom-up controls in regulating pelagic-benthic coupling, biotic complexity, and the partitioning of carbon which determines the fate and cross-shelf transport of biogenic materials.
· Potential food web changes that would influence the transfer of carbon between trophic levels based on remineralization of organic matter, changes in recycling efficiency, and knowledge of biogeochemical cycles.
Additionally, the group made: 1) a list of the core field shipboard measurements for all cruises, 2) a list of required process-type studies, and 3) a list of those sensors to be placed on the moorings.
1) Core shipboard measurements for all cruises, all field seasons include: CTD with rosette, DO, fluorescence, PAR, UV, underway surface observations, seabirds and marine mammal observations, ADCP and sea beam measurements;
2) Required process studies during intense field season work include: DIC, phytoplankton species and HPLC pigments, POC, PON, DOC, DON, tracers, bacteria/microbial sensors, and sediment metabolism studies; and
3) Physical and biochemical measurements on moorings (both current and projected technology) include ice thickness, velocity, temperature and salinity, transmissometer, fluorometric chlorphyll determinations, passive acoustics measurements (marine mammals), active acoustic measurements (zooplankton), vertical particulate fluxes and probes for nitrogen and phosphate.
24 MARCH 2000-MORNING
A time-line for the 5 year field program was proposed. Pat Wheeler shared data from two cruises done in 1996 and she strongly suggested doing two longer cruises, one during the early part (May-June) of the season and one later (July-August) instead of three seasonal cruises. All five lines proposed the first day of the meeting can be covered during each cruise which would give a spatial profile of the biological signals. A September cruise would be a mooring turn-around/limited survey cruise. The second year would be less intense, with only survey measurements on some/all the transect lines in spring, summer, fall. The third year would, once again, be an intensive, process-oriented study program. With this set up, the HEALY would essentially be completely tied up with SBI in 2002 and 2004 from mid-May through September. Lou asked about possibly using other icebreakers for the less intense field seasons, but Mike said we are paying for the ship anyway; let's use her (Table 1).
A discussion ensued about paleoceanography within the SBI program and it was determined that there was a time-scale disconnect between the SBI program and the proposed paleoceanography aspect of SBI. Dennis Darby presented a rationale for some level of paleoceanography in SBI, specifically as providing a sampling platform, but that realistically funds for the science would come from ESH. Therefore, the group supported providing ship support in Year 1 of the field program for surveying for good paleo coring sites during the September mooring deployment cruise, with ship support providing for coring in a subsequent year.
24 MARCH 2000-AFTERNOON
The afternoon session included an update by our international members of SBI-relevant program from their countries. Eddy Carmack (Canada), Paul Wassman (Norway, Igor Melnikov (Russia), and Toshi Takizawa (Japan).
A second topic of discussion was how to plan the Pan Arctic meeting. Mike asked what the group hoped to get out of this meeting and suggested that perhaps we need to put out a call to come – hold a certain number of slots for new, young ideas/persons. We would hold the number of participants to 40: 20 foreigners and 20 Americans.
Mike was still pressing how this meeting will help SBI? Will there be a workshop report? How will it be used? Isn't this effort too late? John Christensen stated that the idea of Pan-Arctic may have initially stemmed from the need to have collaboration with the Russians. However, the original intent of this meeting was, and still is, a pan-Arctic discussion of global change issues between all countries undertaking Arctic research. Overall, there is a need to examine comparative shelf- slope dynamics around the entire region; SBI is just the western component.
During the discussion it was suggested that participants send in an abstract (camera ready) before the meeting which can then be put together for publication. Could it be put out in six weeks? [Ans. YES]. Before the AO comes out? [YES]. Perhaps the document can be transferred across the community via the web [YES]. Who gives the talks or posters, or does everyone give a talk? Pat suggested that a certain number of invited people give 30 minute talks and have everyone else do 5 minute sound-bites with 2 slides, with supported participants providing written extended abstracts.
Table 1. SBI Phase II Field Schedule (* is pre-SBI Phase II).
| Year | Date | Activities | Length |
| *2001 | Sept. | Outer shelf mooring placement | 3-4 wks |
 |
|
|
|
| 2002 | May-June | Intense biological survey & process cruise; 5 lines and repeat | 6-7 wks |
|
|
|
|
|
July-Aug. | Intense biological survey & Process cruise; 5 lines and repeat | 6-7 wks |
|
|
|
|
|
Sept. | Mooring turnaround; Limited line survey
(2?); Paleo survey? |
3-4 wks |
|
|
|
|
| 2003 | May-June | Less intense – limited line survey (?) | 3-4 wks |
|
|
|
|
|
July-Aug. | Less intense - limited line survey (?) | 3-4 wks |
|
|
|
|
|
Sept. | Mooring turn-around; Limited line survey
(2?); Paleo cores collected-SBI logistics only? |
3-4 wks |
|
|
|
|
| 2004 | Feb. | Winter sampling/ice camp | 4-6 wks |
|
|
|
|
|
May-June | Intense process/survey | 6-7 wks |
|
|
|
|
|
July-Aug. | Intense process/survey | 6-7 wks |
|
|
|
|
|
Sept. | Mooring turn-around/survey | 3-4 wks |
|
|
|
|
| 2005 | May-June | Limited line survey | 3-4 wks |
|
|
|
|
|
July-Aug. | Limited line survey | 3-4 wks |
|
|
|
|
|
Sept. | Pull out mooring/final survey | 3-4 wks |
|
|
|
|
| 2006 | |
Synthesis | |
Tentatively, the pan-Arctic meeting is scheduled for the second week in November; travel day on Sunday, with two and one-half days for meeting. Eddy suggested having a half day break in the middle. One full day on Monday, 1/2 day on Tuesday, full day plus banquet on Wednesday, fly back home on Thursday. [Meeting as of May is confirmed for Nov. 5-10, 2000 at the Callaway Gardens near Atlanta, Georgia; 3 day meeting: Tues-Thurs]. A list of potential invitees were identified and added to a previous listing. This list will be circulated within the SSC for discussion, as will suggestions on the meeting format.
The meeting adjourned at 3 pm.