PALMER STATION SCIENCE SITREP FEB 1996 S-003 OZONE DEPLETION, UV-B RADIATION AND VASCULAR PLANT PERFORMANCE IN ANTARCTICA. Thomas Day, Arizona State University, Tempe, Arizona, 85287. PERSONNEL ON STATION: Thomas Day, Carl Grobe, Christopher Ruhland, Jill Balis Cooke. Our main experiment on the Stepping Stones continues to proceed on schedule. Our physiological findings on plant performance this month confirmed our preliminary conclusion from January: both vascular flowering plant species (Colobanthus quitensis and Deschampsia antarctica) perform best (have the highest photosynthetic rates) on cooler days, when canopy air temperatures are less than 15oC. Subsequent laboratory measurements of photosynthetic responses under tightly controlled environmental conditions showed that high air temperatures, not high light, depress photosynthesis in both species under warm sunny conditions. We have also characterized the photosynthetic time response of both species and have found both to be surprisingly fast at responding to changes in PAR or visible light levels. While we have found strong effects of our warming treatments on photosynthesis in the field, UV effects, if they do exist, are less striking and will require more detailed data analysis at the conclusion of the field season. Continued monitoring of reproductive efficiency of these species in our field plots has further supported our January finding that flower production and development is enhanced under our warming treatments. Warming treatments lead to substantially (>50% in some cases) higher flower production in Colobanthus and the developmental stage of flowers in both Colobanthus and Deschampsia are much further along than in their counterparts under ambient temperatures. As is the case with photosynthesis, UV effects on reproduction are much more subtle, if they do exists, and will require more detailed data analysis before conclusions can be made. On 22 February we completed our end of the season analysis of pigment levels in leaves under our field treatments. Along these lines, we have been examining UV-screening compounds (both leaf surface cuticular waxes and internal UV-absorbing flavonoids) along with chlorophyll concentrations. Results from these extractions and spectrophotometric measurements await final data analysis. This month we also characterized soils at our Stepping Stones field site, describing several profiles and collecting samples for further laboratory analyses. Soils consist of a 1-3 cm thick surface horizon of organic material, humus and occasional limpet shells overlaying a B horizon of sand (with some fine clays) which extends down to parent material (granite). On 23 February we began re-censusing several hundred tagged tillers and shoots growing under our field treatments. Completing this growth census is our major field objective before redeployment on March 6; to date this has gone extremely well and the census should be complete before redeployment. This month also saw us complete a census of two contrasting populations of Colobanthus: a previously undocumented population on Gamage Point, which we suspected was newly established, and an older previously documented population on nearby Bonaparte Point. Population age distributions (extrapolated from plant cushion size and allometric relationships) confirm that the population on Gamage Point very likely became established in the past 15 years. This population appears to be expanding rapidly; it already contains 267 individuals. The Bonaparte Point population has a much different size/age distribution, with a far greater proportion of larger, older individuals. Thanks go to all ASA and science event personnel on station as they continued to provide us with excellent, timely support and useful suggestions through our third month at Palmer. S-013 CHANGES IN ADELIE PENGUIN POPULATIONS AT PALMER STATIONS: THE EFFECTS OF LONG-TERM HUMAN DISTURBANCE AND ENVIRONMENTAL CHANGE. William R. Fraser, Montana State Univesity, Bozeman, Montana 59717. PERSONNEL ON STATION: William Fraser, Donna Patterson Annual change in the reproductive biology of Adelie Penguins is thought to be driven primarily by variability in the marine environment. A recent analysis of long-term population trends of Adelie Penguins breeding in the vicinity of Palmer Station, however, has shown high variability between the 5 island rookeries that characterize the local distribution of this species. Thus, although there has been an overall decline of 15% in the Adelie Penguin population as a whole in the last two decades, decreases at the rookery-specific level has varied between 13-43%. A key implication of this analysis is that variability in the terrestrial breeding environment of Adelie Penguins may be an important, but as yet unrecognized determinant of change in the population of this species. The focus of this project, which has a 3-year duration, is to determine what terrestrial variables influence the breeding biology of Adelie Penguins within and between rookeries. Because tourism represents one of these variables, human activity is treated as a component in a matrix. This matrix encompasses several habitat features, and an experimental design structured to permit multiple comparisons between sites to look for effects. Field work on this project, which ended on 15 February, was focused on habitat classification and an assessment of Adelie Penguin reproductive performance at 100 randomly selected sites that encompassed 500 breeding pairs at five rookeries. At this writing, results are preliminary and data analysis incomplete. As a whole, the population exhibited high reproductive success, fledging an average of 1.52 chicks per pair (cpp). Within and between site variability, however, was high, ranging from 1.0 to 1.8 cpp, with sites visited by tourists showing lower but not significantly lower reproductive success (1.45 cpp) relative to the average. In contrast, some sites divorced from this activity but associated with topographic features that, for example, promote high snow deposition, did exhibit significantly lower reproductive success (1.08 cpp). Further data analysis will be required to establish how the various habitat features, including human activity, interact and contribute to Adelie Penguin reproductive performance, and, ultimately, to the factors that determine demographic trends. S-045S LONG-TERM ECOLOGICAL RESEARCH (LTER) ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE DOMINATED ENVIRONMENT. Ray Smith, University of California at Santa Barbara, California 93106. PERSONNEL ON STATION: Janice Jones (shared position with S-045R), Karen Fisher We returned to Palmer Station on 10 February on completion of the annual LTER summer cruise. February 10-12 were spent removing equipment from RV POLAR DUKE and setting it back up on station. February 13-15 were spent setting up the zodiacs and organizing lab 2. The fluorometer was calibrated on 16 February. We did not complete B-E station sampling on 19 February due to weather, only station E was sampled. Full sampling runs were completed from B-E on 21 February and 26 February. We did not complete F-J station sampling on 22 February due to battery failure. A full sampling run was completed from F-J on 27 February. Water collected by S045V from B-E on 15 February, 21 February, 23 February and 26 February was processed for chlorophyll and salinity. Special thanks to Herb Baker for all his help with our sampling zodiac during the season and also during the LTER cruise. Thanks also go to Dave Bell for getting our data back to Santa Barbara so quickly. S-045R LONG-TERM ECOLOGICAL RESEARCH ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINATED SYSTEM. Robin M. Ross and Langdon B. Quetin, University of California, Santa Barbara, California 93106. PERSONNEL ON STATION: Janice Jones (split position with S-045S), Trent Taylor, Christie Lewis We returned to Palmer Station on 10 February on completion of the annual LTER summer cruise. February 10-12 were spent removing equipment from RV POLAR DUKE and setting it back up on station. February 13-15 were spent setting up the zodiacs and organizing Lab 1. We searched for krill unsuccessfully on 17 February. On 18 February, our search was successful. We caught krill near Limitrophe Island, set up an IGR and did a length frequency experiment on the animals. We have searched for krill unsuccessfully since then; 23 February, 24 February and 29 February were all "no krill" days. Acoustics runs from A-E were completed on 19 February, 21 February and 26 February. Runs from F-J were completed on 22 February and 29 February. S-045V LONG TERM ECOLOGICAL RESEARCH ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINATED ENVIRONMENT PHYTOPLANKTON COMPONENT. Maria Vernet, Scripps Institution of Oceanography, La Jolla, California, 92093. PERSONNEL ON STATION: Wendy Kozlowski, Karie Sines, Andrew Greaves The year began for the S-045V on board the Polar Duke; the annual LTER summer cruise was completed on the 11th of February, and all personnel spent the next few days unloading equipment and setting up the labs at Palmer. Maria Vernet, Cristine Moraes and Jonah Rosenfield started the journey home when the ship left Palmer on the 13th. The labs were set up and running shortly after the departure of the Duke. In addition to the usual instruments in Lab 10, a fluorescence detector was added to the HPLC/DAD system for identification of chlorophyll degradation products, and a channel for the analysis of ammonia is currently being added to the nutrient autoanalyzer. The LSC counts were completed for the last of the samples from the cruise, and data analysis continues for HPLC, nutrients and productivity samples from the cruise. Palmer in-shore sampling was resumed on Thursday the thirteenth, with a full run from Stations E to B. Complete sampling at those stations also occurred on the 21st, the 23rd, the 26th and again on the 29th of February. S-O45F LONG-TERM ECOLOGICAL RESEARCH (LTER) ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINATED ENVIRONMENT (SEABIRD COMPONENT). William R. Fraser and Wayne Z. Trivelpiece, Montana State University, Bozeman, Montana, 59717. PERSONNEL ON STATION: William Fraser, Eric Holm Access to nearby islands continued to be good during the month of February with approximately four days lost to poor weather conditions. A sample of 1000 Adelie penguin chicks were banded on Humble Island on 4 February and fledging weights began on the same day. A total of 261 adelie chicks were weighed during the fledging period (2/4-2/23); mean weight did not vary significantly from the 1994-95 season (2921 versus 2961 g). Telemetry continued through 23 February; foraging trip durations averaged approximately 12 hours as compared with 23 hours last season. Diet studies were completed on 19 February with a total of 40 samples collected. Euphausia superba was the dominant dietary component, with size classes exhibiting a bimodal distribution. Censusing of Adelie penguin colonies continued through 16 February to assess fledgling departure rates as part of new protocols introduced this season. Monitoring of Brown and South Polar skuas continued throughout the month of February. Brown skua chicks were banded in early February and fledged during the last week of the month. South Polar skua chick banding continues at this writing. Brown skuas fledged 0.7 chicks per pair this season; the final figure for South Polars is still unknown pending completion of the field season. Chicks are approximately two weeks from fledging and we expect to continue diet and growth studies on Shortcut Island throughout the remainder of the season. Reproductive studies on Blue-eyed shags were completed during the second week of February coincident with fledging of chicks. Kelp gull colonies have been surveyed during the month of February to assess productivity and limpet collection began on 29 February. Giant Petrel banding commenced on 22 February; total number banded for the month was 144 of the approximately 400 chicks within the Palmer Station area. Marine mammal censusing was continuous throughout the month. We would like to thank several members of the Palmer Station community for assistance during the Adelie penguin fledgling work, especially Herb Baker, Carol Crossland, Dave Morehouse and Dave Vella who were instrumental in the chick banding process. S-091 PALMER IRIS SEISMOLOGY. R. Butler/G. Holcomb, U.S. Geological Survey, Albuquerque, NM. PERSONNEL ON STATION: None All USGS operations were normal. S-106 VERY LOW FREQUENCY (VLF) REMOTE SENSING OF THUNDERSTORM AND RADIATION BELT COUPLING TO THE IONOSPHERE. U. Inan, Stanford University. PERSONNEL ON STATION: None On 22 February, the VLF antenna base was repositioned to help stabilize the antenna. All other Stanford VLF operations were normal. S-254 CHLORINE- AND BROMINE-CONTAINING TRACE GASES IN ANTARCTICA. R.A. Rasmussen, Oregon Graduate Institute for Science and Technology, Portland, Oregon, 97291. PERSONNELL ON STATION: None 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. T-257C COLLECTION OF ATMOSPHERIC AIR FOR THE NOAA/CMDL WORLDWIDE FLASK SAMPLING NETWORK. James T. Peterson, Environmental Research Laboratories, National Oceanic and Atmospheric Administration, Boulder, CO 80303-3328. PERSONNEL ON STATION: None 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. J. Prospero/T. Snowdon, University of Miami; C. Sanderson/ N. Chui, EML/DOE N.Y. PERSONNEL ON STATION: None All DEAN/RAMP operations were normal. T-312 TERASCAN SATELLITE IMAGING SYSTEM. R. Whritner, Scripps Institute of Oceanography, La Jolla, CA. PERSONNEL ON STATION: None The TeraScan system collected, archived, and processed DMSP and NOAA telemetry, maintaining a schedule of 15-17 passes per day. DMSP telemetry was archived for S-045S, and imagery was provided to the R/V POLAR DUKE in support of the LTER Cruise. Additionally, AWS data was collected throughout the month from the Hugo Island and Bonaparte Point automatic weather stations. On 04 February, XCAPCON failed to collect 12 of 17 scheduled passes during the night. On 09 February, Dave Menzies of S-045S, the Palmer Station Science Technician, and Instrument Technician Laboratory Operations Ken Earle successfully reinstalled the Bonaparte Point AWS. Normal data collection for the Bonaparte Station resumed on 10 February. On 21 February, the cooling fan on the HR-100 receiver failed and was replaced with the site spare. On 24 February, the Sun SPARCstation automatically rebooted itself. During this reboot, one pass was lost. T-513 UV MONITORING EXPERIMENT. C. Booth, Biospherical Instruments, Inc. PERSONNEL ON STATION: None Preliminary irradiances, integrals, and deduced ozone abundances were calculated on a daily basis in support of science. During the month of February, the 0100, 0200, 0700, and 0800 GMT data scans were removed from the schedule. Throughout the month of January and the first week of February, the UV Monitor was plagued with roofbox temperature alarms. The cause was eventually traced to a bad Fuji temperature controller. On 07 February, the roofbox Fuji controller failed and was replaced with the site spare. After replacing the controller, the temperature regulation problem disappeared. 07122245.325 PLM705.MAR