PALMER STATION SCIENCE SITREP October 1997 Deneb Karentz, SSL NEWS FROM THE LAB Rob Edwards, Senior Assistant Supervisor, Laboratory Operations Palmer Station personnel have been happy to see the lengthening of summer daylight and generally warmer temperatures, but unfortunately local ice and weather conditions have hampered researchers' access to the surrounding marine environment. Sea ice and heavy brash have kept the Zodiacs out of the water for a majority of the month, and high winds have limited their use during open water. All groups have been kept busy with the samples and material they were able to collect, but we're all watching the weather with hopes for a short but strong Northeast wind to open things up again. TOMS images have indicated severe ozone depletion overhead for the last few days of the month, with a very high UV Index of 10 calculated from our ground-based radiometer measurements. After years of data collection, several site visits, and a great number of calculations, Dr. Anthony (Tony) Amos is now able to approximate the times and magnitude of the tides at Palmer Station and Arthur Harbor. Comparisons between predicted and measured tides show a minor temporal offset, which Tony hopes is artificial (i.e. a time-zone problem). If you are interested in receiving monthly tables, please contact Tony directly at AFAMOS@UTMSI.ZO.UTEXAS.EDU. Over the last several months, Facilities staff have completed and tested several improvements to the labs. The fume hood in Lab 4 has been significantly quieted, and the exhaust stack height increased. A backup refrigeration system for the cold rooms is in place and functional. In concert with the Boating Coordinator, an additional water sampling platform was built, which will outfit another Mark V Zodiac for research work. The Wednesday Evening Lecture Series has returned for the summer. We've had enthusiastic response to programs on the McMurdo Dry Valleys, adaptations of cold-blooded animals to polar environments (including some hands-on demonstrations), and video from the sinking of the Bahia Paraiso. Deploying scientists are strongly encouraged to bring slides and materials covering their research or topics of general interest. Presentations are 40-50 minutes, and may be attended by the entire range of station staff. We've just recently discovered the extent of our email problems, which have been occurring over the last month. Apparently changes were made with the routing of email from the satellite downlink in Florida, and communications have not been as smooth as we would like. The transfer of mail to certain domains has become bottled up, and some messages have disappeared completely. The major blockages have now been fixed, and currently there are many parties hard at work to solve any remaining problems. S-002 PHOTOCHEMICAL AND OPTICAL PROPERTIES OF ANTARCTIC WATERS IN RESPONSE TO CHANGING UV-B FLUXES. Kenneth Mopper, Washington State University, and David J. Kieber, State University of New York, College of Environmental Science and Forestry PERSONNEL ON STATION: Brendon Hofsetz, Gary Miller, Joseph Jankowski, Kenneth Mopper, David J. Kieber Since the initial report of the ozone hole over Antarctica, research has focused on evaluating the impact of enhanced UV-B radiation on biological systems in this region. However, little is known about the effects of UV-B on marine photochemistry, which may also impact biological systems. The increase in the UV-B flux should result in an increase in steady-state concentrations of highly reactive transients (e.g., free radicals). Depending on the production rates, steady state concentrations, and the type of cellular damage these species incur, extracellular free radical attack may be important, particularly for those antarctic plankton that do not have adequate photo-repair systems. Experiments are being conducted at Palmer Station to determine: 1) the effect of UV-B on the rate of formation of photochemical species in seawater collected at the LTER station B site, 2) UV-B and UV-A light fluxes employing newly developed nitrate and nitrite chemical actinometers, respectively, and 3) the wavelengths responsible for the formation these photochemical species (action spectra). The third set of experiments are being conducted in collaboration with Dr. Patrick Neale and co-workers (S-010) using their recently developed photoinhibitron system. In addition to these experiments, we initiated a study to assess the role of photochemically formed oxidants (hydrogen peroxide and the OH radical) on the rate of photosynthesis, again, using the photoinhibitron system in collaboration with S-010. The photochemically formed species that we are measuring are the OH radical, hydrogen peroxide, and low molecular carbonyl compounds, including formaldehyde, acetaldehyde, and alpha keto acids. Photoproduction rates are in the low nanomolar/day range for most species, except OH which is in the mid-nanomolar/day range. Preliminary results show that there is a good correlation between UV light flux and photoproduction rates of the various species. Production rates that we have measured at Palmer Station are some of the lowest rates that we have seen in Antarctic waters, owing primarily to the extremely low dissolved organic matter absorbance of the Station B seawater. We measured action spectra for the photochemical formation of hydrogen peroxide and the OH radical. The highest apparent quantum yields are in the UV-B portion of the spectrum, although UV-A wavelengths are also clearly active. One difficulty in obtaining reliable quantum yields is the extremely low absorbances of the seawater in the vicinity of Palmer Station, particularly at wavelengths above 340 nm. Absorbances are similar to those measured for low productivity, open ocean waters. To date, most of our measurements have been conducted on one large seawater sample from LTER Station B off Bonaparte Point. We anticipate repeating the above experiments on a second, long term sample, if ice conditions permit sampling. S-007 UV-PHOTOBIOLOGY OF PLANKTONIC DEVELOPMENTAL STAGES OF ANTARCTIC BENTHIC INVERTEBRATES. Deneb Karentz, University of San Francisco and Isidro Bosch, State University of New York, Geneseo PERSONNEL ON STATION: Isidro Bosch, Deneb Karentz, Ross Hein, David Krakowski and Mario Pineda Plankton collection work aimed at determining the distribution of embryos and larvae in the water column has been hampered by ice conditions. This month we were able to complete two depth profiles to determine larval abundance, light penetration in the water column, vertical changes in temperature, conductivity and density, and chlorophyll concentrations. Preliminary observation indicates that substantial numbers of sea star, tunicate, and nemertean worm larvae are present in the top 30 m of the water column, including the surface layer. Our efforts this month were primarily devoted to studies of UV effects on the development of the common sea star Psilaster charcoti. The embryos of this species are easily obtained and cultured in the laboratory. Adults are reproductive primarily in October during the time of ozone depletion. Experiments have shown that the eggs and embryos produced by P. charcoti are highly buoyant and probably float very near the surface of the ocean, where they might be subject to intense UV radiation. We know of many other Antarctic invertebrate species with buoyant eggs. Psilaster is therefore an excellent model for our study of the consequences of ozone depletion. Six SCUBA dives were made under solid pack to collect adults from Arthur Harbor and Hero Inlet. Adults were induced to spawn with 1-methyladenine. Dose response experiments were conducted on a variety of developmental stages to identify the most sensitive periods in the life cycle. Cultures have also been maintained outdoors in running seawater tanks with a variety of filters and neutral density screens. These experiments will provide information on the responses of embryos to different levels of ambient light. The data also indicate a certain degree of variation of UV tolerance within the species. Such intraspecific differences between individuals is of particular interest in evaluating the potential ecological impact of ozone depletion. In the few days where our study site at Hero Inlet was free of ice we carried out field exposures by suspending cultures at fixed depths within the water column on a buoyed array for 1 to 4 days. Experimental cultures are being monitored for survivorship and time of development. In addition to these measures of gross morphology, assays for protein ubiquitination (a mediator of cytoplasmic repair mechanisms) are currently under way. One of the most interesting aspects of the species Psilaster is a tremendous variation in egg size and color within the population. These differences in egg type may be responsible for the significant variation in response to UV we have seen within this species. Samples for the determination of egg size, dry and organic weight, protein, lipid and carotenoid content of 23 females used in our UV experiments have been collected and are now being analyzed. The results of these analyses will be compared to the results of our light exposure experiments to test for the correlation between egg quality and UV tolerance. The spawning period of Psilaster has essentially ended. We have already started working on our next model system, the sea urchin Sterechinus neumayeri, which becomes reproductive in November and will serve as the focus of our work throughout the month of November. A major effort that has already been initiated is the application of an immunofluorescent technique for the quantitation of DNA damage sites in sea urchin embryos. The adaptation of this technique to invertebrate embryos will provide a powerful tool for our studies of UV-related damage in field collected larvae. Other work on Sterechinus has focus on the spawning behavior of the adults. With the new digital video system and underwater housing on station we have been documenting the potential aggregation of this species at spawning. A coordinated spawning response would maximize fertilization success and limit the exposure of the highly vulnerable egg stage to ultraviolet light. Additional work has been continuing on the MAA content of various tissues of the limpet Nacella concinna. Weekly collections of adults are being analyzed for the presence of specific UV-absorbing compounds, the mycosporine-like amino acids. This monitoring program will help us in documenting the responses of this dominant shallow water species to UV stress. S-010 NEW APPROACHES TO MEASURING AND UNDERSTANDING THE EFFECTS OF ULTRAVIOLET RADIATION ON PHOTOSYNTHESIS OF ANTARCTIC PHYTOPLANKTON. Patrick J. Neale, Smithsonian Environmental Research Center PERSONNEL ON STATION: Richard F. Davis, Jennifer J. Fritz, Patrick J. Neale This project uses new techniques to measure and interpret the spectral and temporal dependence of phytoplankton photosynthetic response to ultraviolet radiation (UV, 280-400 nm). Field activities at Palmer Station began on October 1, 1997. A new spectral incubator ("photoinhibitron") was set up in the Bio Lab. In this incubator, eighty aliquots of as much as 15 ml can be simultaneously incubated in eight different broad-band spectral regimes. The irradiance source is a 2.5 kW Xenon lamp, which is directed through long-pass cutoff filters with nominal cutoff wavelengths of 280, 295, 305, 320, 335, 350, 370 and 395 nm. Spectral irradiance in the incubator is measured using a spectroradiometer system with a fiber optic probe that is calibrated on site with a 1000W standard lamp. The incubator is an improvement over the original photoinhibitron previously used in studies at McMurdo and the Weddell-Scotia Confluence which had a maximum sample size of 2 ml. As of October 30th, Arthur Harbor waters have been sampled four times at approximately weekly intervals and photosynthetic rate (radiocarbon incorporation) was determined over one hour incubations in the new photoinhibitron. On the only day (October 21st) when zodiac operations were possible, LTER station B was sampled. On other days, bucket samples were obtained near the seawater intake on Gamage Point or off Bonaparte Point. Preliminary results suggest that the incubator performs quite well, with acceptable levels of sample variation despite a substantial representation in the flora of large (greater than 100 micron) forms such as the diatom Corethron sp. and Phaeocystis antarctica colonies. The temporal dependence of photosynthetic response to UV is being studied using the recently developed technique of pulse amplitude modulated (PAM) fluorometry, which measures the time variation of photosynthetic quantum yield during UV illumination with minutes resolution. This instrument is performing well on Arthur Harbor samples, however we have had to concentrate samples (using Nitex screens) to obtain sufficient signal levels. The chlorophyll concentration in our samples has been less than 1 milligram per cubic meter. An overall goal of our work is to refine models for predicting the effect of UV, in particular the variation in UV-B (280 to 320 nm) due to ozone depletion, on Antarctic primary productivity. Implementation of the model requires high-resolution spectral data on incident UV, as well as spectral attenuation through water and ice. The Biospherical Instruments (BSI) SUV-100 monitors the long-term variation of incident spectral UV at Palmer Station, and is currently operating at a 15 min sampling interval. During S-010 deployment October through December 1997, this record is being supplemented by a Smithsonian Institution SR-18 UV-B spectroradiometer, situated next to the SUV-100. This radiometer measures incident insulation over the spectral range of 290 to 324 nm with 2 nm resolution (FWHM) and at 330 nm at 10 nm resolution. The sample rate is fourteen spectra per minute which are averaged over one minute periods. The SR18 is also calibrated on site using a portable calibrator with a 1000W standard lamp. Solar intercomparisons were also conducted between the SUV, the SR-18, the Palmer Station PUV-500 and GUV-511 (BSI medium resolution instruments), and another S-010 instrument, the Satlantic OCP-100. Attenuation coefficients for downwelling UV and PAR were obtained using the PUV instrument in collaboration with S-007 (Karentz and Bosch), open water conditions permitting (two occasions). We are also collaborated with S-007 to deploy PUV with divers under the ice and compare with the OCP-100 at the surface to measure spectral transmission through the pack ice which has covered Hero Inlet since October 22. During October we also conducted measurements of the diurnal variation of photosynthesis in Arthur Harbor samples incubated in outside tanks that either transmit UV, block UV or transmit UV-A (320 to 400 nm) but block UV-B. We also collaborated with S-002 (Mopper and Kieber) to measure rates of photochemical peroxide production in sample water from Arthur Harbor under exposure to irradiance in the photoinhibitron. This data will be used to construct a polychromatic action spectra for peroxide production. We also conducted several tests of a system to scrub radioactive carbon dioxide gas produced during the photosynthesis measurements. We would like to thank the Palmer Station staff for helping out in all phases of operations, particularly Rob Edwards and John Powell for instrument support, William Arens for getting the data acquisition computers going, and Steve Navarro for skillful construction with plexiglas. S-035 LONG-TERM ECOLOGICAL RESEARCH (LTER) ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINATED ENVIRONMENT (SEABIRD COMPONENT). William R Fraser Montana State University, Bozeman, MT. PERSONNEL ON STATION: Peter Duley and Matt Irinaga We arrived at Palmer on the first of October. Arthur Harbor and the surrounding waters out to Bisco Bay were frozen over with pack ice. The NBP had to break up the ice in Hero Inlet in order to offload cargo and crew. Access to local islands and study sites have been kept to a minimum during the month of October. Heavy pack ice moving in and out of the area as well as high winds made it possible to boat on only 4 days this month. The ice broke up on October 7 with winds out of the North East at 25 with gusts to 50. October 7 was also the first day Adelie penguins were noted on Torgerson Island. Upon our arrival we began the tasks of preparing the materials necessary to conduct our field work. The field notebooks have been set up and the Adelie penguin bands have been color-coded for use in the reproductive success in control and impact study sites on Torgerson Island. All of the limpet size distribution analysis has been completed and cormorant diet analysis was finished as well. Boating and Islands courses have been completed. Arrival dates, indicator counts, and band reading were done for Adelies on Torgerson, Litchfield, Humble, Cormorant, and Christine Islands on the days in which we were able to get out. Marine mammal surveys were also conducted on these ice free days. New born Weddell, and elephant seals have been noted in Hero inlet and on Litchfield Island respectively. Our first brown skua was spotted on October 17th. S-013 CHANGES IN ADELIE PENGUIN POPULATIONS AT PALMER STATION: EFFECTS OF LONGTERM HUMAN DISTURBANCE AND ENVIRONMENTAL CHANGE. William R Fraser Montana State University, Bozeman,MT. PERSONNEL ON STATION: Peter Duley and Matt Irinaga We arrived at Palmer on the first of October. Arthur Harbor and the surrounding waters out to Bisco Bay were frozen over with pack ice. The NBP had to break up the ice in Hero Inlet in order to offload cargo and crew. Access to local islands and study sites have been kept to a minimum during the month of October. Heavy pack ice moving in and out of the area as well as high winds made it possible to boat on only 4 days this month. The ice broke up on October 7 with winds out of the North East at 25 with gusts to 50. October 7 was also the first day Adelie penguins were noted on Torgerson Island. Upon our arrival we began the tasks of preparing the materials necessary to conduct our field work. The field notebooks have been set up and the Adelie penguin bands have been color-coded for use in the reproductive success in control and impact study sites on Torgerson Island. All of the limpet size distribution analysis has been completed and cormorant diet analysis was finished as well. Boating and Islands courses have been completed. Arrival dates, indicator counts, and band reading were done for Adelies on Torgerson, Litchfield, Humble, Cormorant, and Christine Islands on the days in which we were able to get out. Marine mammal surveys were also conducted on these ice free days. New born Weddell, and elephant seals have been noted in Hero inlet and on Litchfield Island respectively. Our first brown skua was spotted on October 17th. S-085 GPS CONTINUOUS OPERATION REFERENCE STATION. J. Mullins, U.S. Geological Survey The system has been monitored by the station science technician. For the month of October, GPS data was collected nearly continuously. Daily data was converted to a RINEX format, compressed, and FTPed to Reston, VA. The average daily data transfer to Reston was 2.27 MB. On 03 October, the end time was changed on the RINEX converter from 12:00:00 AM to 11:59:45 PM. This change was required to eliminate duplicate records in the daily RINEX files. On October 07 and 09, extensive work was done on the S-085 Windows NT PC. This included reconfiguring the CPI cards, replacing a questionable ethernet card, replacing a faulty CPU and motherboard, and upgrading to 32 MB of RAM. As a result of this work, the DGPS system's reliability was improved dramatically, and no data loss occurred for the remainder of the month. 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. On 29 October, the vault was entered between 1830 - 1842 UT to perform scheduled battery maintenance. 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 October 29, synoptic recordings were halted from 1930 - 1945 UT in order to perform maintenance on the Ampex recorder. During this down time, the scrape-flutter idler was cleaned, lubricated, and the bearing tension was adjusted. S-204 MEASUREMENTS OF ATMOSPHERIC O2 IN RELATION TO THE GLOBAL 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. On 13 October, the systems PC clock was advanced one hour to follow Palmer Station's change to Daylight Savings Time. 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 October, 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. Additionally, one TOVS ozone concentration map was produced and provided to local science groups on station. During the month, communications with Denver and SeaSpace were initiated regarding the upcoming TeraScan upgrade. During the first half of the month of October, occasional dropout of DMSP telemetry was noted. 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. Scheduled absolute calibration scans were performed on 08 October and 22 October. On 10 October, the Fuji monochromator temperature controller failed. The failed controller was replaced with the site spare.