PALMER STATION SCIENCE SITREP February 1997 William R. Fraser, SSL The following science projects were active at Palmer Station during the month: NEWS FROM THE LAB Alice Doyle, Assistant Supervisor, Laboratory Operations The R/V POLAR DUKE arrived on station mid-month after the completion of the annual LTER cruise. The portcall went smoothly accomplishing all that needed to be done before the ship headed north to Punta Arenas. In addition to the return of the LTER scientists, four new science groups arrived on station bringing eleven additional people into the labs. The incoming groups were S-030 (Davison), S-034 (Emslie), S-036 (Sidell), S-037 (Detrich). Their arrival has created a bit of a space crunch but everyone has been very accommodating and cooperative in helping each other meet their needs. The Beckman Ultracentrifuge has been repaired and returned to Palmer Station. The timing is perfect as the science groups that will use the instrument just arrived on station. The instrument technician, Brad Gore, is currently working hard to install the instrument. Many thanks to Beckman and ASA logistics for the quick repair and return to station. As mentioned in last month's sitrep, Laboratory Services is collecting weather data from an automated system. This system is composed of the following sensors: Licor 1000-16 Air temperature, Licor Quantum sensor, Licor pyranometer sensor, Vaisala relative humidity sensor, and a precipitation gauge. All channels except the precipitation are collecting the average, high and low for each hour. The precipitation channel is collecting a total over a 24 hour period. The data is downloaded ever other week and is available to all. Please contact me at doyleal@palmer.usap.nsf.gov if you are interested. S-003 OZONE DEPLETION, UV-B RADIATION AND VASCULAR PLANT PERFORMANCE IN ANTARCTICA. Thomas A. Day, Department of Botany and The Center for the Study of Early Events in Photosynthesis, Arizona State University. PERSONNEL ON STATION: Thomas A. Day, Christopher T. Ruhland, and Fusheng Xiong. Studies continued on the effects on UV-radiation and warming on the only two native Antarctic vascular plants Deschampsia antarctica (grass) and Colobanthus quitensis (forb). Temperature- induction response curves were performed on both species early in the month in the lab at Palmer Station. Whole plant gas exchange rates and modulated chlorophyll fluorescence measurements were made at various temperature regimes to examine the effects of warming on the photosythetic apparatus of both species of plants. Diurnal trends of photosynthesis were examined over the course of the day at Stepping Stones Island at various times throughout the month. Final concentrations of chlorophyll (total, a & b) and bulk concentrations of flavonoids and related phenolics were measured in the laboratories at Palmer Station from samples removed from our treatment cages. In addition, a final demographic growth analysis as well as a reproductive stage census was performed on tagged tillers or branches of each species under each treatment replicate. S-013 CHANGES IN ADELIE PENGUIN POPULATIONS AT PALMER STATION: EFFECTS OF LONG TERM HUMAN DISTURBANCE AND ENVIRONMENTAL CHANGE. William R. Fraser, Montana State University. PERSONNEL ON STATION: William R. Fraser (shared with S-035). The conceptual model guiding this aspect of our research is described for S-035. Tourist numbers, movements and distribution on Torgersen Island were documented through censuses and mapping coincident with visits by tour ships until mid-February. Data collection on habitat-specific reproductive success and demography at 770 nest sites located in 66 Adelie Penguin colonies was completed on 7 February as part of an effort to document the effects of variability in the terrestrial nesting habitat. Preliminary analysis of the data suggests that reproductive success varied in accordance with specific habitat features independent of the effects of the marine environment. Low level aerial photography of colonies ended on 3 February. A final aerial survey of all colonies was completed with support from H.M.S. Endurance. S-016 LONG TERM ECOLOGICAL RESEARCH ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINANTED ENVIRONMENT (Phytoplankton Component). Maria Vernet, Scripps Institution of Oceanography. PERSONNEL ON STATION: Wendy Kozlowski, Karie Sines, Joe Fontaine and Eric Holm (shared position with S-035). We arrived at Palmer on February 13th, after the completion of the annual January LTER cruise. The first few days back on station were dedicated to offload and setting up of the laboratories, and on February 19th, we resumed Palmer inshore sampling with water collection at stations E and B. Full profile sampling runs were also completed on the 24th and 28th. In addition, all remaining HPLC pigment samples from the January cruise were analyzed, and all pre-cruise nutrient samples were analyzed for Nitrate+Nitrite and Silicate this month. S-019 REPRODUCTIVE ENDOCRINOLOGY OF FREE-LIVING ADELIE PENGUINS ON TORGERSEN ISLAND, ANTARCTICA. Carol Vleck and Theresa Bucher, Iowa State University. All personnel departed Palmer Station on 15 February. S-028 LONG-TERM ECOLOGICAL RESEARCH ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINATED SYSTEM (Prey Component). Robin M. Ross and Langdon B.Quetin, University of California, Marine Science Institute, Santa Barbara. PERSONNEL ON STATION: Janice Jones (shared with S032), Karen Haberman (shared with S032), Tracy Shaw and Doug Conlin We returned to Palmer Station on 13Feb following the annual LTER cruise. We spent several days unloading equipment from the RV Polar Duke and setting it up again in lab 2 and the aquarium room at Palmer. The trawl zodiac was set up and taken out for a check out run on 19Feb. No krill were seen and the new personnel were shown winch operation and 1m ring net trawl procedure. On 20Feb, an acoustic run was started at station J but we were called back to station after only 10 minutes when the wind picked up to over 20kts. On returning to station we found the krill were still in the intertidal zone so we collected animals using mesh scoops. A growth rate experiment was started and animals were measured for length frequency. The krill had been in the intertidal zone since 12Feb but were gone on 21Feb and did not return. An acoustic run from station A to station E was done on 24Feb. No krill were visible on the acoustic trace. No trace has been completed between stations J and F since returning from the LTER cruise due to bad weather and high winds. Karen Haberman's krill feeding rate experiments on diatoms and Phaeocystis, which began in December, were continued through January and February. Phytoplankton cultures were grown in the environmental chambers, and krill were maintained in the indoor aquaria. S-032 LONG-TERM ECOLOGICAL RESEARCH (LTER) ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE DOMINATED ENVIRONMENT (Modeling Component). Ray Smith, University of California, ICESS, Santa Barbara. PERSONNEL ON STATION: Janice Jones (shared with S-028), Eric Vanek. We returned to Palmer Station on 13Feb following the annual LTER cruise. Several days were spent unloading equipment from the RV Polar Duke and setting up lab 2 and the aquarium room at Palmer. ROZE, the electronic zodiac, was set up during a very short dry spell on 18Feb. We attempted to sample on 20Feb but were called back to station due to high winds. CTD, PRR and water collection for salinity and chlorophyll determination was carried out at stations E and B on 24Feb, and at stations E, H, and J on 28Feb. Water was also collected at Bonaparte Point and Gamage Point on 24Feb. A CTD cast was done for tide gauge calibration on 25Feb. S032 would like to thank all the ASA staff here at Palmer Station for their assistance, it was great to have extra help while settling back into our regular station sampling routine. S-034 PALEO-HISTORY OF THE PALMER LONG-TERM ECOLOGICAL RESEARCH (WESTERN ANTARCTIC PENINSULA) REGION. Stephen Emslie, Western State College. PERSONNEL ON STATION: Stephen Emslie, Michele Sewolt Dr. Steve Emslie and his field assistant, Michele Sewolt, arrived at Palmer Station on 1 March to begin research at abandoned penguin rookeries in the Palmer region. The research will be include surveying and excavating abandoned penguin rookeries accessible by zodiac from Palmer. Surveys of the area began on 3 March. S-035 LONG TERM ECOLOGICAL RESEARCH ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINATED ENVIRONMENT (Seabird Component). William R. Fraser, Montana State University PERSONNEL ON STATION: Donna Patterson and William R. Fraser (shared with S-013). A key assumption guiding LTER seabird research is that the persistence of any seabird population reflects the coincident availability of suitable nesting and foraging habitats. Variability in one or both of these habitats is thus viewed as being an important determinant of change in the magnitude and/or direction of seabird populations. Within this conceptual model, research by the seabird component of the LTER focuses on understanding how the physical environment influences the abundance and distribution of prey on which these predators depend. The terrestrial aspects of this model are embraced in the scope of objectives described for S-013, with which the LTER seabird work shares resources, personnel and data. Both programs also contribute to the broader, international objectives of the CCAMLR Ecosystem Monitoring Program, which in the U.S. falls under the direction of the National Marine Fisheries Service. LTER-related field work on Adelie Penguins encompasses three categories: breeding biology, foraging ecology and demography. One thousand chicks were banded on Humble Island on 2 February in accordance with protocols for long-term demographic research. Fledging weights began on the same day and were concluded on 18 February. A total of 364 chicks were recaptured for weighing; mean fledgling weight was slightly higher this season as compared with 1995-96 (3039 vs. 2921 g). Adelie Penguin diet studies were completed on 15 February; 45 stomach samples were obtained for the season. The primary component of the stomach contents continued to be Euphausia superba. Only four samples contained fish and no amphipods or alternate prey items were found. Thysanoesa macrura appeared in only three samples. Size classes represented were predominantly 31-35 and 36-40 mm (68% of krill measured) unlike the extreme bimodal distribution seen in the 1995-96 samples. Adelie Penguin telemetry studies were concluded on 20 February coincident with the fledging period. Data analysis of foraging trip durations is pending. Baseline breeding and population data on other area seabirds were, as in the past, obtained opportunitically to maintain continuity in databases that in some cases span more than two decades. We would like to thank several members of the Palmer Station community for their assistance during the Adelie penguin fledging work, especially Sharon Delsack, Tim Cully, Mark Rosen, and Polly Penhale who were of great assistance in the chick banding process. We also thank Sheldon Blackman for consistent maintenance of radio communications and Randy Sliester for prompt assistance with all boating needs. S-091 GLOBAL SEISMOGRAPH STATION AT PALMER STATION. R. Butler, Incorporated Research Institutions for Seismology (IRIS) No personnel were on station. The system has been monitored by the station science technician. Operations continued without interruption throughout the month. S-106 STUDIES OF LIGHTNING-INDUCED ELECTRON PRECIPITATION OF THE IONOSPHERE. U. Inan, Stanford University. No personnel were on station. The system has been monitored by the station science technician. On 18 February, the eight posts holding the guys for the antenna tower were reset, as were the western post on the E/W loop and the post supporting the pre-amplifier. S-204 MEASUREMENTS OF ATMOSPHERIC O2 IN RELATION TO THE GLOBAL CARBON CYCLE. Ralph Keeling, Scripps Institution of Oceanography No personnel were on station. Air samples are collected on a semi-weekly basis by the station physician. The samples are return shipped to Scripps for analysis of O2 and CO2 content. The goal of the program is to resolve seasonal and interannual variations in atmospheric O2 (detected through changes in O2/N2 ratio) which can aid in the determination of rates of marine biological productivity and ocean mixing and aid in the separation of the global sink for anthropogenic CO2 into terrestrial and oceanic components. The program involves air sampling at a network of sites in the Northern and Southern Hemispheres. Palmer Station is especially well situated to resolve signals due to carbon cycling in the Southern Ocean. S-254 CHLORINE-AND BROMINE-CONTAINING TRACE GASES IN ANTARCTICA. R.A. Rasmussen, Oregon Graduate Institute for Science and Technology No personnel were on station. Air samples are taken on a weekly basis by the station physician. The samples are returned to the Institute for analysis of a number of trace components, especially chlorine- and bromine-containing gases. These elements have been implicated in the chemical processes that contribute to the austral-spring depletion of the ozone layer over Antarctica. This work will contribute to a better understanding of the buildup of trace constituents, particularly those of high-latitude marine origin. S-257C COLLECTION OF ATMOSPHERIC AIR FOR THE NOAA\CMDL WORLDWIDE FLASK SAMPLING NETWORK. James T. Peterson, Environmental Research Laboratories, National Oceanic and Atmospheric Administration No personnel were on station. Air samples are taken on a weekly basis by the station physician. The National Oceanic and Atmospheric Administration (NOAA) Climate Monitoring and Diagnostics Laboratory team continue long-term measurements of trace atmospheric constituents that influence climate. The Palmer Station air samples are returned to the NOAA laboratory for analysis of trace constituents, including carbon dioxide. These measurements are part of NOAA's effort to determine and assess the long-term buildup of global pollutants in the atmosphere. These data will be used to determine how the rate of change of these parameters affects climate, particularly by including them in climate model studies. S-275 UM/DOE-EML REMOTE ATMOSPHERIC MEASUREMENTS PROGRAM. C. Sanderson, Department of Energy, Environmental Measurements Laboratory No personnel were on station. The system has been operated by the station science technician. One sample filter was exposed for the duration of each week, and a weekly schedule of calibration, background, and sample counts was maintained. The air intake was examined for moisture on 14 February; none was found. T-312 TERASCAN SATELLITE IMAGING SYSTEM. R. Whritner, Scripps Institution of Oceanography No personnel were on station. The system has been operated by the station science technician. Throughout the month of February, the TeraScan system collected, archived, and processed DMSP and NOAA telemetry, maintaining a schedule of 15-17 passes per day. NOAA and DMSP telemetry were archived for S-032 when the LTER grid was clear. AWS transmissions were monitored from Bonaparte Point, Hugo Island, and RACER Rock. A DMSP visible image of the region from Anvers Island to Adelaide Island was produced and transferred to the R/V POLAR DUKE to assist LTER in cruise track planning. On 23 February the GPS clock that provides time marking for the TeraScan computer reported no satellites available for roughly 90 minutes. Time marking resumed with no operator intervention. T-513 UV MONITORING NETWORK. C. Booth, Biospherical Instruments, Inc. No personnel were on station. The system has been operated by the station science technician. Throughout the month, raw irradiance data were collected daily and transmitted to BSI, and preliminary irradiances and integrals were produced in support of Science. Further investigation of the power supply failure of 31 January revealed that the internal response lamp had also failed. The instrument was removed from the roofbox on 04 February, and the lamp was replaced. After the instrument was reinstalled in the roofbox, a response scan was successfully run using the backup power supply. Later on 04 February a modified version of the software was installed, allowing the computer to control the on/off status of the power supply, removing the need for operator intervention during response scans. An absolute scan was performed on 05 February with the seasoned lamp. A scheduled absolute calibration was performed with the site standard lamp on 24 February.