PALMER STATION SCIENCE SITREP FEBRUARY 1994 S-013 LONG-TERM ECOLOGICAL RESEARCH (LTER) ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINATED ENVIRONMENT (SEABIRD COMPONENT). William R. Fraser/Wayne Z. Trivelpiece, Montana State University, Bozeman, MT. Personnel on station: William Fraser, Donna Patterson Our research at Palmer Station, initiated in October, continued during the month of February with minimal loss of time due to weather. Four field team members (Tracy Mader, Eric Holm, Doug Wallace and Allan Williams) departed Palmer in early February during the SAAM flight evolution. Studies on Adelie Penguins were concluded on 25 February, which marked the end of the chick fledging period on Torgersen and Humble islands. Peak fledging occurred on 15 February. Adelie reproductive success was high this season (1.65 chicks creched per pair), but mean fledging weight did not vary from that recorded last season (3100 grams). The birds weighed included nearly 40% of the chicks from a 1000-chick sample banded on 3 February as part of long-term demographic studies. Krill predominated in the diets of Adelie Penguins throughout the season, although foraging trip durations exhibited considerable week-to-week variation, being shorter at the begining and end of the season (6-8 hours) and longer in the middle (12-18 hours). Based on pelagic seabird censuses conducted as part of the January LTER cruise, Adelies exhibited a highly dispersed distribution within their foraging range, which was not the case last season when most foraging birds were observed withn 5 km of their rookeries. South Polar and Brown skua reproductive sites continued to be studied on six islands at 3-5 day intervals to determine hatching dates, chick growth rates and diets. Results at this writing suggest that both species are experiencing a poor season. Coincident studies related to Kelp Gulls, Cormorants, Giant Petrels, Chinstrap Penguins and marine mammals are continuing with the objective of obtaining basic annual data on reproductive success, breeding chronology, population status and diet. Results of this work will be presented in March. Two tour ships visited Palmer Station during the month of February. As part of a recently funded effort to examine human impacts on certain wildlife populations, tourist visits were monitored on Torgersen Island to obtain preliminary data on tourist flow, and to compare aspects of Adelie reproductive biology and ecology with control sites not visited by tourists. This study is embedded within the ongoing AMLR and LTER programs, meaning identical research methods and the full suite of protocols have been implemented at tourist-visited sites to develop a comparative study. S-014 ENERGETICS OF THE ADULTS AND LARVAE OF ANTARCTIC KRILL, EUPHAUSIA SUPERBA. Langdon Quetin/Robin Ross, U. California at Santa Barbara Personnel on station: Robin Ross, Johana Squier During February one objective was to maintain and increase phytoplankton cultures in preparation for experiments on growth and starvation tolerance of larval krill planned for April and May. In addition assistance was given to the Pal LTER project to allow sampling of the water column at the ten standard Palmer grid stations to continue from mid-February to mid-March. Pigments from these water samples are being determined with HPLC (high pressure liquid chromatography) on station. S-016 LONG-TERM ECOLOGICAL RESEARCH (LTER) ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE DOMINATED ENVIRONMENT. Barbara B. Prezelin, U. California at Santa Barbara Personnel on Station: Sandra Roll, T.J. Evens, Bill Golden, Julie Standish After completion of the LTER January cruise S-016 spent their time preparing for redeployment to the States. Since this is the last season that Barbara Prezelin will be involved with the LTER all of the essential materials for continuing her part of the core data set were turned over to Dr. Robin Ross. T.J. Evens will be staying on station until the 23rd of March to complete HPLC phytoplankton pigment analysis of approximately 600 samples taken on the January cruise. The other members of the group left on the February 18th Polar Duke shuttle. No other sampling by S-016 will be attempted. S-028 LONG-TERM ECOLOGICAL RESEARCH (LTER) IN THE ANTARCTIC: AN ICE DOMINATED ECOSYSTEM - SECONDARY PRODUCTION. Robin Ross/Langdon Quetin, U. California at Santa Barbara Personnel on station: Karen Haberman Feb 1-28; Tim Newberger, Robin Ross and Jen Zamon Feb 8-28, Truc Nguyen Feb 17-28. Experiments on the interaction between a dominant grazer, Antarctic krill, and the phytoplankton community continued throughout February. Grazing experiments in the laboratory contrasted rates on a diatom, Thalassiosira sp., a prymnesiophyte, Phaeocystis sp, and a mixture of the two. The form of the prymnesiophyte, single or colonial, and its physiological state were additional variables. HPLC (high pressure liquid chromatography) analysis of samples from experiments with natural phytoplankton communities suggested that ingestion rates on diatoms were much higher than those on the prymnesiophyte. The different components of the phytoplankton community were identified by chemotaxonomic markers (pigments measured with HPLC). HPLC analysis was delayed until late February when a missing part for the instrument arrived. Most personnel arrived on station Feb 8, after the month long Pal LTER cruise. During the last day of the cruise (Feb 7) we sampled the Palmer grid (nearshore) stations to compare the seasonal cycle observed with the nearshore sampling to the greater spatial scle of the entire Peninsula grid. Growth and spawning experiments started near Adelaide Island on the cruise were completed on station, the laboratory was set up to continue the nearshore sampling of the Palmer grid until mid-March, and preparations for the site review committee visit (Feb 11-14) were completed. Samples from the cruise for total pigment content in krill, an index of immediate food availability to krill were analyzed. Highest values were found in krill collected in Crystal Sound, near the marginal ice zone where high chlorophyll a values were also found. In addition retrograde for UCSB and equipment for storage in the warehouse in Punta Arenas was inventoried and packed. Sets of acoustic transects and standard zooplankton tows for both the transect from Arthur Harbor to outside Laggard Island, and the transect on the outside of Litchfield and Spume Islands were completed during the weeks of Feb 14 and 21. Successful targetted tows for antarctic krill during both weeks yielded enough krill to conduct instantaneous growth rate experiments, measure a subsample for length frequency distributions, and freeze both measured individuals and groups of the same sex for analysis of proximate chemical composition at UCSB. Growth rates were generally low. Most krill were either about 25 mm long or between 35 and 45 mm, and not reproductively mature. During the latter half of February, krill were found at Palmer dock several mornings, with some washed up on the rocks. S-032 LONG-TERM ECOLOGICAL RESEARCH (LTER) ON THE ANTARCTIC MARINE ECOSYSTEM: AN ICE-DOMINATED ENVIRONMENT. Ray C. Smith, U. California at Santa Barbara Personnel on Station: Tim Newberger, Sharon Stammerjohn, Philip Handley The Palmer area field sampling program resumed early this month after our return from the annual January cruise on board the Polar Duke. Three weeks of sampling with the CTD (Conductivity Temperature and Depth) and the OFFI (Optical Free Fall Instrument) have been completed at the 10 LTER nearshore stations as well as collection and analysis of water samples for chlorophyll analysis. Archival and preliminary processing of data is up to date. Packing and retrograde of gear used on board the Polar Duke is nearing completion. S-182 THE ROLE OF FRAZIL AND ANCHOR ICE IN SEDIMENTATION IN SUBPOLAR GLACIAL MARINE ENVIRONMENTS, ANTARCTICA. Gail M. Ashley, Rutgers University, New Brunswick, NJ Norman D. Smith, University of Illinois, Chicago, IL Personnel on Station: Gail Ashley, Norman Smith, Matthew Goss, Peter Smith The objectives of the study are to further understand sedimentation processes near the margins of subpolar tidewater glaciers. Data consist of: (1) video surveys of the ice terminus and the ice-proximal sea bottom with a ROV, (2) CTD profiles, water samples and sediment-trap catches to study processes and patterns of sediment dispersal and sedimentation, and (3) bottom cores and grabs to document the record of recent glacial marine sedimentation. The study tests the hypothesis that frazil ice and anchor ice form in glacial meltwater flowing into subpolar marine water and may produce deposits different from those formed in temperate and polar glacial environments. Field work was completed Feb. 7. During February, the glacier front was resurveyed. No change in position occurred during the 2-month field season. CTD's were collected daily (weather permitting) at 7 stations to monitor structure of the water column under a variety of tide, wind (direction and magnitude) and brash ice conditions. Experiments were conducted in both the laboratory and natural environment to determine melting rates of brash ice of different densities and under different magnitudes of agitation. A series of measurements were made of size distribution of brash ice produced by the calving glacier. An 80 sq meter area was encircled with an oil-spill boom and all ice bergs measured. Gravity cores of bottom sediment were collected and x-rayed. The remote operated vehicle (ROV) powered by a generator was deployed from zodiacs and video recordings were made of the ice- proximal sea bottom and ice front. Swarms of krill were found adjacent to ice front (at 42 m depth). Electronic problems affecting quality and performance of the ROV continued to plague operations and excessive "down time" prevented use of the ROV as a useful research tool. S-210 AN EXPERIMENTAL STUDY OF TROPOSPHERIC SULFUR CHEMISTRY IN ANTARCTICA. Harald Berresheim/Fred L. Eisele, Georgia Institute of Technology, Atlanta, GA/National Center for Atmospheric Research, Boulder, CO. Personnel on Station: Harald Berresheim, Fred Eisele, Robert Thorn, Anne Jefferson. Measurements 1. DMS was continuously measured both in air and in surface seawater. Seawater samples were obtained from Arthur Harbor and from open ocean LTER stations. 2. The selected-ion mass spectrometry system was reconfigured to switch from DMSOx measurements (made in Jan. 1994) to measurements of OH, H2SO4, and MSA(gas) in Feb. 1994, with 30 sec time resolution for each compound. The modified system became fully operative on Feb. 4. 3. Aerosol filter measurements of sulfate, methanesulfonate (MSA,p), chloride, and other particle-associated ions continued. One filter sample each day and one sample each night were obtained, with interruptions only during precipitation and/or heavy pollution events. Aerosol number and size distributions, classified into 32 channels, ranging over 12 nm - 0.6 æm diameter, were continuously scanned. 4. Unfortunately, measurements of atmospheric SO2 suffered from several technical problems. Only a few days of data, mainly in the last third of February, could be recorded. 5. Auxiliary measurements of nitric oxide (NO) at 60 sec resolution, as well as acoustic sounder recordings of mixed layer height and/or cloud ceiling, in situ ozone and high precision water vapor monitoring continued throughout the whole month. Carbon monoxide (CO) was measured on an 'as needed' basis during the second half of February. 6. UV/VIS data and meteorological data were continuously obtained and logged from BSI and Station Met sensors, respectively. Results Preliminary results obtained during the total field period (Jan/Feb 1994) are given in the following section, as far as they can be interpreted at this time. As outlined above, multiple interdependent parameters were being measured during the present field project. Statistical correlations between individual variables as well as final data evaluations for most parameters and post-mission analysis (e.g., for aerosol ions) will be conducted during the forthcoming months. Clearly, atmospheric DMS levels showed a correlation with both wind direction and wind speed. More than 300 measurements have been obtained, mostly on a 2-hourly basis, with values ranging between 6-595 pptv (median: 99 pptv). Lowest levels were correlated with northerly winds and low wind speeds (air passing over glacier). Highest levels correlated with easterly winds (air from productive inshore waters) and southerly wind directions (air from open ocean), and high wind speeds. Overall, the atmospheric levels of DMS showed two major maxima, one right at the beginning of the measurements (Jan. 14), presumably at the end of a major plankton blooming event, and the second on Jan. 30 and 31 (high wind speeds). Surface seawater DMS levels in Arthur Harbor showed no sign of a major phytoplankton bloom (ca. 2 nM). However, samples from productive open ocean stations collected by the ship's crew and the LTER groups showed a factor of 2-4 higher DMS levels. About 10% of the entire measurement period consisted of days with intensive sunshine driving the atmospheric photochemical oxidation of DMS. The DMS oxidation products DMSO and DMSO2 were measured during 5 days in January and, at least on one day, peaked at relatively high levels (up to 20 pptv) suggesting that their formation compared to other products is important in polar latitudes. Though quite low, hydroxyl radical (OH) concentrations were measured under both clear and cloudy skies. These data in conjunction with our ancillary measurements of ozone, water vapor, carbon monoxide, and nitric oxide now provide the basis for testing photochemical models of the Antarctic troposphere. As the primary radical responsible for initating the oxidation of DMS the concentration of OH together with that of DMS provide a measure of the rate of the total product formation from DMS. The two sulfur products of most interest for the February portion of the present study, i.e., gas phase sulfuric acid and MSA, are both believed to be responsible for the size growth of aerosol particles in the marine atmosphere. The former is also thought to be responsible for new particle production through gas-to-particle conversion processes. Both the production of sulfuric acid and MSA and their attachment to or growth of aerosols is thought to be highly temperature dependent. In contrast to our previous studies in the mid-latitudes and tropics, Palmer station offers consistently low temperatures in an overall pristine environment. In the present study we observed MSA concentrations significantly exceeding those of sulfuric acid. This has important ramifications both for understanding the DMS oxidation process and also for determining the relative concentrations of sulfuric acid and MSA incorporated into particles which are eventually deposited onto the Antarctic ice sheet. A better understanding of the variations in the sulfuric acid/MSA concentration ratio as a function of temperature will contribute to using this ratio as a tracer for the origin of air masses which have deposited these compounds on the ice sheet. Preliminary results of this study compared to the above mentioned previous studies at lower latitude sites suggest that this ratio might vary by an order of magnitude with just a 15-20 degree C temperature change. Overall, our measurements at Palmer Station were very successful. They included the first time measurements of OH, gas phase MSA and H2SO4, NO, DMSO, and DMSO2 made in Antarctic latitudes. Unique to the present study was also the fact that, for the first time anywhere, such a complete set of reactant and product sulfur compounds has been measured simultaneously. The results provide a detailed data base for modelling the general atmospheric photochemistry and, in particular the photochemistry of DMS over the coastal Antarctic peninsula. S-212 CLOUD CONDENSATION NUCLEI: A LINK BETWEEN OCEANIC SULFUR AND CLIMATE AT PALMER STATION, ANTARCTICA. V. Saxena, North Carolina State University/ T. DeFelice, U. Wisconsin at Milwaukee Personnel on Station: Tom DeFelice The objectives of the study were to: (1) monitor the activity spectrum of cloud condensation nuclei and relate it to dimethylsulfide (DMS) concentrations in the marine environment of Palmer station, (2) investigate the role of cloud condensation nuclei (CCN) in the cloud-topped marine boundary layer with regard to the extent of cloud coverage and precipitation efficiency of clouds, and (3) collect samples of precipitation and the ice core from the Marr Piedmont Glacier, Anvers Island on days of opportunity. The DMS concentrations were simultaneously monitored by a complementary project, S-210 (Georgia Institute of Technology). The aerosol data collection continued at its "hectic" pace. Cloud active aerosols were monitored around the clock using a combination of the following methods: (1) CCN Spectrometer (Saxena-Fukuta), (2) 47 mm membrane filters, and (3) sequential and event-wise sampling of precipitation. On 02/02/94 a 5 ft. long, 4" diameter ice core was retrieved from the Marr Piedmont Glacier, Anvers Island. The core contains snow samples for the preceding 3 years. The PI will visit the same site next year and recover a similar ice core. The analysis of the core samples will help determine the post-depositional changes in the snow. Briefly, the PI's investigations are aimed at providing information on atmospheric transfer functions and initiate an understanding of the ice core records in terms of the recent climate history by analyzing the ongoing depositional processes. As of this writing, 45 precipitation samples have been collected (13 with collected volumes <5 ml. sampled on a very fine event-wise time scale; i.e. 10-40 min.); 34 membrane filters exposed in addition to monitoring the CCN activity spectrum at regular intervals. The frequency of CCN spectral measurements increased in association with the passage of cloud systems, and the local wind circulations (i.e., sea/land breeze) during February. The increased frequency of the CCN measurements in association with the passage of cloud systems and the local wind circulations led to the detection of the "frontal boundary (mesoscale and synoptic scale)", upper level disturbance, and inhomogeneously mixed areas of the cloud system. This confirms the results of DeFelice (and Saxena, 1994; Atmospheric Research) who found that CCN spectral measurements made before, during and after cloud system passages could detect the actual "frontal boundary" as well as its beginning and end. DeFelice (& Saxena) also reported an example of nuclei generation (termed 'nucleation burst' by the PI) during the drop-to-particle phase of a cloud system. However, the burst was not always found and its occurrence appears to be dependent on the number concentration of evaporating clouddroplets and their chemical composition, the physical and chemical composition of the interstitial nuclei, the gas phase composition and the meteorology of the air-mass. One of the most significant preliminary results to date in the present study is the confirmation of the occurrence of 'nucleation bursts' phenomenon on Jan 19 and 20, and on February 17. The January '94 report detailed the importance of such occurrences despite their rare occurrence (e.g. 3 in 35 days). Thus this climatically important phenomena may easily go undetected. There was also an enhancement of cloud condensation nuclei measured on February 25 in the vicinity of evaporating raindroplets. An additional set of in-situ cloud microphysical and ionic chemistry of cloudwater measurements would be ideal in future trips to Palmer (TD). These would allow for a more quantitative understanding of the physico-chemical process involved with "nucleation bursts", and the potential environmental impact by cloud systems on Palmer. Such measurements could be done with minimal additional cost due to the relatively low frequency of occurrence of cloud events during this period. One closing remark worth recapitulating is that cloud condensation nuclei spectral measurements made in conjunction with meteorological, microphysical, gas phase and aqueous phase chemistry measurements could provide a greater understanding of the climatically important 'nucleation burst' phenomenon, and the environmental impact from cloud systems. The PI feels gratified by the documentation of the 'nucleation bursts phenomenon at Palmer Station. Tom DeFelice would like to thank Professor V Saxena and the office of Polar Programs for an opportunity to participate in this field experiment. S-254 CHLORINE- AND BROMINE-CONTAINING TRACE GASES IN ANTARCTICA. R.A. Rasmussen, Oregon Graduate Institute for Science and Technology. There are no personnel 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-257 SOUTH POLE MONITORING FOR CLIMATE CHANGE. James T. Peterson, Palmer Station, Environmental Research Laboratories, National Oceanic and Atmospheric Administration. There are no personnel 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-091 PALMER IRIS SEISMOLOGY. R. Butler/G. Holcomb, U.S. Geological Survey, Albuquerque, NM No personnel were on station. The system has been monitored by the station science technician. The DP computer restarted well and switched tape drives following a power outage on February 15. The station continued to be plagued by impulsive events of widely variable frequency and intensity, though the frequency of these pulses diminished greatly toward the end of the month. S-106 VERY LOW FREQUENCY (VLF) REMOTE SENSING OF THUNDERSTORM AND RADIATION BELT COUPLING TO THE IONOSPHERE. U. Inan, Stanford University. The PI was on station between February 11-14. During the PI's visit, a software upgrade was performed, possible sites for relocation of the antenna were investigated, and maintenance was performed on the ground cable in Hero Inlet. The PC was demultiplexing the narrow band data when a power outage longer than the capacity of the UPS occurred on February 15, causing the loss of the day's data. Several IF gains and the frequency standard were adjusted near the end of the month. 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. The pump was off for approximately one hour during a power outage on February 15. 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. DMSP and NOAA telemetry were collected, processed, and archived. Large scale weather images were produced in support of Science. T-313 UV MONITORING EXPERIMENT. C. Booth, Biospherical Instruments, Inc. No personnel were on station. The system has been operated by the station science technician. Irradiance data were collected daily and transmitted to ATSVAX for BSI. The 1400 UT scan on February 15 was lost during a power outage. An absolute calibration was performed on February 21 with the standard lamp. The scan schedule was adjusted in response to the darkening sky conditions. Preliminary irradiance data and inferred ozone abundances were produced in support of Science. 01140738.512 PLM043.MAR 04161547.450 PLM174.MAY