PALMER STATION SCIENCE SITREP APRIL 2000 NEWS FROM THE LAB Rob Edwards, Supervisor, Laboratory Operations April was a transition month in many ways at Palmer Station. On 1 April, Raytheon Polar Services took over the USAP support contract from ASA. While this is no doubt a large overall change for the program, the apparent effects on station were small, as all support staff on station continued with their jobs, largely business-as-usual. The LTER deployed scientists returned home at the end of March, so April was largely devoted to the support of BO-022-O in the labs and the Science Tech projects up in T-5. Most of the winter support staff were already deployed, and work was begun on the winter remodeling projects at the first opportunity. Of course, the most significant changes were those that occur every year as the season changes to winter. The late breeding wildlife rushed to complete it's business, marine and terrestrial plants senesced under the reduced light and temperatures, and snow and ice began to accumulate. The following projects performed research at Palmer Station; BO-022-O CHEMICAL ECOLOGY OF SHALLOW-WATER MARINE MACROALGAE AND INVERTEBRATES ON THE ANTARCTIC PENINSULA. Chuck Amsler, Jim McClintock, University of Alabama at Birmingham, and Bill Baker, Florida Institute of Technology, Co-PI's. Personnel on Station: Chuck Amsler, Bill Baker, Bruce Furrow, Joanna Hubbard (TEA), Katrin Iken, Andy Mahon. The focus of research in April was preparing extracts of marine macroalgae and invertebrates for use in bioassays, conducting bioassays, and continued collecting, observational and photodocumentation diving. Three bioassays were operational, including a sea star feeding deterrence assay, an amphipod feeding preference assay, and a fish feeding preference assay. Resource allocation theories were tested within several invertebrates using bioassay and high-pressure liquid chromatographic methods. Two web sites are being supplied with progress from our efforts (http://WOW.uab.edu and http://tea.rice.edu/tea_hubbardfrontpage.html). Overall, this field season was highly successful in collection of specimens and evaluation of their chemical ecological properties. GO-052-P GPS CONTINUOUS OPERATION REFERENCE STATION. J. Mullins, U.S. Geological Survey The station science technician has monitored the system. During the month, GPS transmissions were collected continuously, converted daily to a RInEx format, compressed, and transmitted to the US Geological Survey in Reston, VA. Several server outages in Reston briefly delayed the transfer of a few data files. Images showing ground control points from Cormorant, Litchfield, and Biscoe Point islands were annotated and sent, along with GCP coordinates and pixel positions, to the USGS in Reston. On 16 April, two epochs of CORS data were lost, and about eight hours of data were of substandard quality, for no apparent reason. The problem appeared and disappeared spontaneously and was only noted retroactively during a cursory data quality check. The roving Z-12 receiver was used for real time kinematic surveys of two plant study plots on Stepping Stones Islands. GO-091-O GLOBAL SEISMOGRAPH STATION AT PALMER STATION. R. Butler, Incorporated Research Institutions for Seismology (IRIS) The station science technician has monitored the system. Global seismic events were recorded throughout the month. All system operations were normal. AO-106-O STUDIES OF LIGHTNING-INDUCED ELECTRON PRECIPITATION OF THE IONOSPHERE. U. Inan, Stanford University Personnel on station: Chris Barrington-Leigh The annual site visit took place this month. A major upgrade to the VLF equipment in the Clean Air/VLF hut was undertaken. Nearly half of the old rack equipment was removed for retrograde and replaced with two new computers, a new piece of software, and an upgrade to existing software. Of the three computers in the hut, two are now surveying narrowband VLF transmitters in order to record ionospheric modifications due primarily to lightning electron precipitation from the inner radiation belts. The third computer will for a year duplicate the function of the reel-to-reel Ampex recorder by recording full-spectrum broadband data for 1 minute of every 15. In 2001, the Ampex unit and programmer clock will be retired, and one of the three equipment racks in the hut can be sent north. The new computer-based system is accompanied by a new filter/interface box which passes twice the frequency bandwidth that was available to the previously existing equipment. This may allow new exploration in the lower LF band. In addition, a new geographic axis alignment was implemented for the VLF antenna on the glacier, and routine maintenance was conducted on the antenna and the feed-line running between the hut and the antenna. The antenna is now ready for winter and is aligned more accurately than ever before. OO-204-O MEASUREMENTS OF ATMOSPHERIC O2 IN RELATION TO THE GLOBAL CARBON CYCLE. Ralph Keeling, Scripps Institution of Oceanography 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. OO-254-O CHLORINE-AND BROMINE-CONTAINING TRACE GASES IN ANTARCTICA. R.A. Rasmussen, Oregon Graduate Institute for Science and Technology 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. OO-264-O COLLECTION OF ATMOSPHERIC AIR FOR THE NOAA\CMDL WORLDWIDE FLASK SAMPLING NETWORK. James T. Peterson, Environmental Research Laboratories, National Oceanic and Atmospheric Administration 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. This data will be used to determine how the rate of change of these parameters affects climate, particularly by including them in climate model studies. OO-275-O DOE-EML REMOTE ATMOSPHERIC MEASUREMENTS PROGRAM. C. Sanderson, Department of Energy, Environmental Measurements Laboratory The station science technician has operated the system. One sample filter was exposed for the duration of each week, and a weekly schedule of calibration, background, and sample counts was maintained. The RAMP system is part of a global network seeking to characterize the quantity and distribution of radionuclide particles occurring both naturally and artificially in the atmosphere. OO-283-P ANTARCTIC AUTOMATED WEATHER STATIONS. Charles Stearns, University of Wisconsin The station science technician has monitored the local sites. Automated Weather Station (AWS) transmissions were monitored from Bonaparte Point, Hugo Island, and RACER Rock using the TeraScan system. The Bonaparte Point unit continued to send an invalid wind speed, presumably due to a CPU failure. TO-312-O TERASCAN SATELLITE IMAGING SYSTEM. R. Whritner, Scripps Institution of Oceanography The station science technician has operated the system. Throughout the month, the TeraScan system collected, archived, and processed DMSP and NOAA satellite pass telemetry, maintaining a schedule of 19-23 passes per day. One or two encrypted SeaWiFS passes were also collected and archived each day until 11 April, at which point the SeaWiFS sensor was shut off over the Antarctic due to low sun angle. NOAA, DMSP, and encrypted SeaWiFS telemetry were archived for BP- 032-O when the LTER grid was clear of clouds. 85 GHz SSM/I ice concentration images were produced and sent to BP-032-O on a weekly basis. When clear skies made it worthwhile, at roughly five to seven day intervals, images showing the area north of the Larsen Ice Shelf were prepared and emailed to the PI of GO-096-O to allow him to track conditions prior to his cruise in May. The TeraScan's failure to automatically update its orbital elements was traced to an unannounced directory change on the SeaSpace ftp server. Automatic updating resumed after the local script was adjusted appropriately. TO-513-O UV MONITORING NETWORK. C. Booth, Biospherical Instruments, Inc. The station science technician has operated the system. Throughout the month, raw irradiance data scans were collected daily and transmitted to BSI, and preliminary irradiances and spectral integrals were produced in support of Science. Absolute calibration scans were performed as scheduled.