PALMER STATION SCIENCE SITREP APRIL 1996 The following science projects were active at Palmer Station during the month: S-013 SEABIRD INVESTIGATIONS AT PALMER STATION AS PART OF THE NMFS/AMLR ECOSYSTEM MONITORING PROGRAM. William R. Fraser, Montana State University, Bozeman, MT. 59717 No personnel were on station. Station personnel continued weighing and measuring Giant Petrel (Macronectes giganteus) chicks on Humble Island on a weekly or, weather permitting, twice weekly basis. S-016 LONG TERM ECOLOGICAL RESEARCH (LTER) ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE DOMINATED ENVIRONMENT. PHYTOPLANKTON COMPONENT. Maria Vernet, Scripps Institution of Oceanography, Marine Research Division, La Jolla, CA 92093-0218. No personnel were on station. Station personnel collected and filtered weekly water samples for later analysis of chlorophyll content. S-091 PALMER IRIS SEISMOLOGY. R. Butler, U.S. Geological Survey, Albuquerque, NM. No personnel were on station. The system has been monitored by the station science technician. On 17 April, the vault was accessed to re-evacuate the bell jars and recenter mass positions on the seismometers. All other USGS operations were normal for the month of April. S-106 VERY LOW FREQUENCY (VLF) REMOTE SENSING OF THUNDERSTORM AND RADIATION BELT COUPLING TO THE IONOSPHERE. U. Inan, Stanford University. No personnel were on station. The system has been monitored by the station science technician. On 25 April, someone from the dump cleanup crew inadvertently cycled power to the Clean Air building while resetting a tripped breaker in the T-5 circuit panel. The Stanford VLF system recovered normally and no data was lost. 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, OR 97291 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. J.T. Peterson, Environmental Research Laboratories, National Oceanic and Atmospheric Administration, Boulder, CO 80303-3328. 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. J. Prospero/T. Snowdon, University of Miami; C. Sanderson/N. Chui, EML/DOE N.Y. 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 16 April, the DEAN pump was turned off for several minutes to get power from a different circuit. The pump had been on the same circuit as the outside outlet, which was being used by the dump cleanup crew. There was concern that some of the dump crew's equipment might trip the breaker. On 25 April, while resetting a tripped breaker, someone from the dump cleanup crew inadvertently cycled power to the DEAN/RAMP equipment from the breaker panel. It was necessary to manually restore the MCA HV power and restart calibration counting. The MCA HV power was off for one hour during this time before the problem was discovered. T-312 TERASCAN SATELLITE IMAGING SYSTEM. R. Whritner, Scripps Institute of Oceanography, La Jolla, CA. No personnel were on station. The system has been operated by the station science technician. Throughout the month of April, 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-032, and AWS data was collected from the Hugo Island and Bonaparte Point automatic weather stations in support of the LTER project. Additionally, 85 GHz SSMI data was collected and provided to Bob Whritner in support of the R/V POLAR DUKE's operations in the Weddell Sea. Also, several DMSP infrared images of the Weddell Sea were collected and provided to the R/V POLAR DUKE. During the month, the TeraScan 2.6 software upgrade was installed. On 22 April, the TeraScan officially began collecting data using the new software. T-513 UV MONITORING EXPERIMENT. C. Booth, Biospherical Instruments, Inc. No personnel were on station. The system has been operated by the science technician. All UV Monitor operations were normal. Preliminary irradiances, integrals, and deduced ozone abundances were calculated on a daily basis in support of science. During the month, an absolute calibration scan was performed using the site standard lamp. Additionally, PMT high voltage levels were increased and the 1000, 1100, 2100, 2200, and 2300 Z data scans were removed from the schedule in response to decreasing sun elevations. 03130637.450 PLM154.MAY