PALMER STATION SCIENCE MONTHLY REPORT October 2004 NEWS FROM THE LAB Langdon Quetin, Station Science Leader The summer science season at Palmer Station began with the arrival of Brett Pickering, B-013-P/L (Fraser, PI), and Ryan Said, A-306-P (Inan, PI), on October 3, 2004. Later in the month, October 23, additional personnel representing projects B-013-P/L and B-198-P (Fraser, PI), B-003-P (Day, PI), B-016-L/P (Vernet, PI), B-028-L/P (Ross and Quetin, PIs), B-032-L/P (Smith, PI), B-045-L/P (Ducklow, PI) arrived at Palmer Station. There are presently 14 scientists on station. Research Associate, Johan Booth, continues to oversee data collection for 10 research projects, operate and maintain on-site equipment for the Palmer tide gage, and serve as chief weather observer for the station. Reports specific to these projects and activities are below. Palmer Station continued to be iced in with minimal sea ice travel and boating during October. Periodically the route near the trolley across Hero Inlet to Bonaparte Point was available for foot travel. The Laurence M. Gould cut a track through the fast ice in Arthur Harbor on October 23, which enabled the prevailing north wind to open enough area for 2 days of boating. Then the south wind once again prevailed, sea ice moved back into Arthur Harbor, and water sampling and diving activities were restricted to the vicinity of Hero Inlet and Gamage Point. Water sampling and diving near Gamage Point would not have been possible without the addition of the new aluminum landing craft, affectionately coined the Tin Can, to the stations fleet for the month of October. Though one of the primary missions of the Tin Can is to support field camp deployment, we have found it a very effective sampling and diving platform in light ice. Its ability to move easily in 5 - 8 cm of new ice has allowed us to sample locally earlier than in previous years. We would have been station-bound for the month of October without the use of this craft. Briefly, air temperatures for the month averaged -4.2 degrees C, ranging from -17.7 degrees C to 5.2°C, early in the month. Wind averaged 11 kts and peaked at 66 kts October 1. We have had 51 mm of melted precipitation and 25 cm of snow. Maximum snow stake depth was 69 cm October 23. For this year to date we have had 483 mm of melted precipitation and 236 cm of snow. More weather details can be found in the Meteorology report below. Logistically, this has been an excellent start to the 0405 science season at Palmer Station. We, in the science community, realize this success is due to the planning and efforts of many people, both here at the station and more remotely at the Office of Polar Programs, RPSC headquarters, Port Hueneme, Santiago and Punta Arenas. Thank you. B-003-P: RESPONSE OF TERRESTRIAL ECOSYSTEMS ALONG THE ANTARCTIC PENINSULA TO A CHANGING CLIMATE Thomas A. Day, Principal Investigator, Arizona State University, Tempe, AZ. Personnel on station: Sarah Strauss, David Bryant and Michell Thomey Our main objective for the month of October was to prepare the tundra microcosm boxes behind station for this seasons climate manipulation experiments. We arrived at Palmer Station on October 23 after an extremely smooth crossing. The first three days on station were spent unpacking. Once we had organized our lab, we began removing 8" of snow and at least 4" of ice from the 20 microcosm boxes. The folks at FEMC have cut gray mats to simulate the albedo characteristics of Antarctic granite. We are waiting for better weather to attach the mats to the plywood tops of the plots. The IR heaters, and dummy heater controls, were reattached to the frames, plugged in and found to be operational. We are currently leaving the heaters turned off since the experiment is not starting until the snow melts from the tundra microcosms in the several weeks. Construction of UV filters and the metal frames to hold them still need to be assembled and attached to the boxes. In the lab, we have set up and calibrated the instruments we brought down for measuring photosynthesis and respiration during our experiment. Thanks to Barb Watson for her assistance in setting up the regulators and gauges for our gas cylinders. The persistent snow and ice on and around station have prevented us from beginning our sampling and surveying on the surrounding islands. The snow pack over the microcosm cores we collected last year for our experiment has also prevented us from making baseline measurements of respiration and photosynthesis before the experimental treatments begin. Thanks to all Palmer station personnel who have helped us move in and set up. We would especially like to thank Brad Kuehn and the other workers at FEMC for their help in setting up the heaters and mats. Also thanks to Dan Weisblatt for connecting the heaters. Thanks to Steve Barten and Ken Navarro for their logistics support and Cara Sucher for helping insure that all our equipment arrived safely on station. B-013-L/P: PALMER, ANTARCTICA LONG-TERM ECOLOGICAL RESEARCH PROJECT: Long-Term Ecological Research on the Antarctic marine ecosystem: Climate migration, ECOSYSTEM response and teleconnections in an ice-dominated environment: SEABIRD COMPONENT William R. Fraser, Principal Investigator, Polar Oceans Research Group, Sheridan, MT. Personnel on station: Brett Pickering (Report combined with B-198-P below) B-198-P: MONITORING THE EFFECTS OF TOURISM AND ENVIRONMENTAL VARIABILITY ON ADELIE PENGUINS AT PALMER STATION, ANTARCTICA William R. Fraser, Principal Investigator, Polar Oceans Research Group, Sheridan, MT. Personnel on station: Dan Evans Early season fieldwork has been severely limited by sea ice thus far. During the crossing, bands of pancake ice were encountered at 59.5 degrees south latitude. Ice bands continued to be met sporadically until the LMG came out of the Neumayer Channel when we encountered well formed first year floes and fast ice. Arriving at Palmer Station on the third of October, most of the sea surface was ice covered. Although Arthur Harbor has not yet been ice-free this month, storms and warm temperatures have precluded the possibility of establishing a sea ice route to area islands. When the LMG returned on October 23 with Dan Evans we were met with some luck. Before docking the ship was able to make a pass through Arthur Harbor to break up the ice. A cooperating wind was blowing and swept some of the ice out of the harbor. With the assistance of the Marine Technicians and Boating coordinator in the new landing craft, we reached Torgersen and Dream Islands to take censuses of colonies and measure snow depths. The next day we made it to Christine Island using a Zodiac, but by the time we returned the ice was pushing back into Arthur Harbor. An attempt was made to reach Torgersen subsequently, but ice conditions did not allow us to reach the island. The remainder of the month was spent at the station due to ice. Time spent on station allowed us to get set up for the field season. We were able to process frozen samples from last season; set up lab and office space; prepare field notebooks and gear; and maintain databases. Palm Pilots and databases were set up and tested. R.P.S.C support has been incredible in helping us get set up this year. Special thanks to Toby Koffman and Pete Dalferro for boating support; Cara Sucher, Sonya Wolter and Barb Watson for lab supplies and support; and Chris Vitry and Shayne Clausson for help with computers and software. B-016-L/P: PALMER, ANTARCTICA LONG-TERM ECOLOGICAL RESEARCH PROJECT: Long-Term Ecological Research on the Antarctic marine ecosystem: Climate migration, ECOSYSTEM response and teleconnections in an ice-dominated environment: PHYTOPLANKTON ECOLOGY COMPONENT Dr. Maria Vernet, Principle Investigator, Scripps Institution of Oceanography Personnel on station: Karie Sines, Eli Loomis Personnel arrived on station on October 23 after a smooth and pleasant crossing. Ice remained in the harbor through the end of the month, with the exception of a few short-lived leads allowing for completion of boating one and boating two. During this time the group was able to complete unpacking, laboratory setup and some instrument testing. The phytoplankton component of the core sample set as designated by the Palmer Long Term Ecological Research group scientists includes filtration for particulate carbon and nitrogen, pigment analysis using high performance liquid chromatography, measurement of dissolved inorganic nutrients, and estimation of primary production by measurement of 14C uptake using an on-deck incubator to simulate in situ conditions. Additional samples are being collected for measurements of endpoint 18O levels, for experiments on the effects of microzooplanton grazing on chlorophyll biomass, and for DMSP levels at offshore Station E. Continuous, daily data is collected on photosynthetically available and ultra violet radiation. We would like to thank the Palmer Lab Staff and the IT department for their efficient help in lab move-in and the boating coordinator and carpenters for their assistance in platform setup and maintenance. B-028-L/P: PALMER, ANTARCTICA LONG-TERM ECOLOGICAL RESEARCH PROJECT: Long-Term Ecological Research on the Antarctic marine ecosystem: Climate migration, ECOSYSTEM response and teleconnections in an ice-dominated environment: PREY COMPONENT. Drs. Robin Ross and Langdon Quetin, Principal Investigators, Marine Science Institute, University of California at Santa Barbara Personnel on station: Langdon Quetin, Joshua Sprague We arrived at Palmer Station October 23 aboard the Laurence M. Gould, earlier than originally planned due to a change in the ship schedule. We quickly moved into our labs and the dive locker thanks to the organization and effort of Cara Sucher, Barb Watson and Sonja Wolter prior to our arrival, and the efficiency with which cargo from the ship was distributed by Ken Navarro and Steve Barten. The boating coordinator, Toby Koffman, thankfully made the effort to give us both the Boating I and II checkouts during a short period of open water after the departure of the LMG. We have been iced in since then except for a small area in the vicinity of Gamage Point. To make a long thank you list shorter, thanks to everyone on station, this has been a great start to our Palmer science season and rapid assimilation into station life. October 28 we, LQ, KS and JS, did our first dive from the new aluminum landing craft (dubbed the "Tin Can"" until a more suitable name is coined). The dive went well, and we needed only minor weight adjustments. The extra room aboard the Tin Can and the bow ramp made dressing for a dive and getting in and out of the water much easier than on a Mark V zodiac. The phytoplankton cultures are in good condition. To date we have finished taping and weighing all the vials for the Pal0405 season and Jan05 cruise. We have begun measuring samples from the IGR experiments done during cruise Jan04. The acoustic fish we tow from the Mark V zodiac was modified, thanks to Jeff Gustafson, to accept the larger transducer of the new BioSonics DTX system. Design and construction of the new console for the DTX system will follow. Despite being iced in, we have had a great start to the season and will soon be sampling krill under the pack ice. Thank you to everyone on station and the RPSC folks in Denver. Even with the change in the ship schedule, this season has started without a glitch. B-032-L/P: PALMER, ANTARCTICA LONG-TERM ECOLOGICAL RESEARCH PROJECT: Long-Term Ecological Research on the Antarctic marine ecosystem: Climate migration, ECOSYSTEM response and teleconnections in an ice-dominated environment: BIO-OPTICS, REMOTE SENSING, SEA ICE COMPONENT Dr. Raymond C. Smith, Principle Investigator, ICESS, University of California at Santa Barbara Personnel on station: Austen Thomas, Katherine Schwager Personnel arrived on station on October 23. Ice remained in the harbor through the end of the month. A few days of boating allowed for completion of boating one and boating two. The laboratory is setup and some instrument testing has begun. The bio-optical component of the LTER collects CTD (conductivity, temperature and density, outfitted with a transmissometer and fluorometer also) and PRR (Profiling Reflectance Radiometer) data whenever we sample from the water column. Samples are collected for discrete chlorophyll a levels and analyzed immediately back at Palmer Station. We would like to thank the Palmer Lab Staff and the IT department for their help in lab move-in and the boating coordinator and carpenters for their assistance with platform maintenance and setup. B-045-L/P: PALMER, ANTARCTICA LONG-TERM ECOLOGICAL RESEARCH PROJECT: Long-Term Ecological Research on the Antarctic marine ecosystem: Climate migration, ECOSYSTEM response and teleconnections in an ice-dominated environment: Microbial/biogeochemistry component Dr. Hugh Ducklow, Principal investigator, School of Marine Science, The College of William and Mary Personnel on station: Hugh Ducklow, Michele Cochran and Nicole Middaugh We arrived at Palmer Station in a snowstorm early on 23 October aboard LMG 04-13A. Some icebreaking by the departing LMG and favorable winds opened the sea enough for us to complete Boating II on 25 October, but since then our sampling activities have been limited by sea ice and brash ice all around Hero Inlet, Arthur Harbor and the channels between the Islands. The last week of October was occupied mainly with setting up our lab for the third season of sampling by the LTER Microbial component. Although sea ice cover prevented us from accessing routine LTER sampling Stations B and E, we were able to carry out sampling in Arthur Harbor using the new aluminum landing craft. Boating Coordinator Toby Koffman outfitted her with a davit and winch and piloted her through the ice. We've now sampled the water column 4 times under a 5-10 cm layer of new sea ice. Preliminary results indicate typically low levels of bacterial abundance and activity. Thanks to everyone on station for helping us get set up and sampling promptly. Special thanks to Cara Sucher, Barb Watson and Sonia Wolter for equipping and staging our lab, Ken Navarro and Steve Barten for logistics help and the LMG officers, crew and RPSC team for getting us here safely. G-052-P GPS CONTINUOUSLY OPERATING REFERENCE STATION Jerry Mullins, Principal Investigator, U.S. Geological Survey The Research Associate operates and maintains on-site equipment for the project. Throughout the month, 15-second epoch GPS data files were collected continually at station PALM, compressed, and transmitted to the USGS in Reston, VA. GPS data was captured at a sampling rate of 2 Hz for a full day as a test run of support planned for several upcoming joint NASA - Chilean Navy aerial glacier surveying missions. Operations appeared to proceed smoothly, as only one minor data gap was encountered, and the standard 15second epoch data collection was performed in parallel and was unaffected. When sampling rate of the receiver was returned to 15 seconds, however, approximately eight hours of the standard data collection appeared to be corrupted for no apparent reason. In subsequent periods of highspeed sampling, the return to regular speed will not be performed so close to a day or week boundary, and the data quality will be monitored immediately in hopes of avoiding or handling a recurrence of this problem. G-090-P GLOBAL SEISMOGRAPH NETWORK (GSN) SITE AT PALMER STATION Rhett Butler, Principal Investigator, Incorporated Research Institutions for Seismology (IRIS) The Research Associate operates and maintains on-site equipment for the project. Station PMSA is one of more than 130 sites in the GSN monitoring seismic waves produced by events worldwide. Data files are recorded to tape and also sent real-time to the U.S. Geological Survey. O-202-P ANTARCTIC METEOROLOGICAL RESEARCH CENTER (AMRC) SATELLITE DATA INGESTOR Charles Stearns, Principal Investigator, University of Wisconsin The Research Associate operates and maintains on-site equipment for the project. The AMRC SDI computer processes satellite telemetry received by the Palmer Station TeraScan system, extracting Automated Weather Station information and low-resolution infrared imagery and sending the results to AMRC headquarters in Madison, WI. A new computer was received to replace a unit with a failed hard drive, configured properly for the Palmer network and the default use of the UT time zone, and placed into operation. O-204-O A STUDY OF ATMOSPHERIC OXYGEN VARIABILITY IN RELATION TO ANNUAL TO DECADAL VARIATIONS IN TERRESTRIAL AND MARINE ECOSYSTEMS Ralph Keeling, Principal Investigator, Scripps Institution of Oceanography The station physician collects air samples semiweekly. The goal of this project is to resolve seasonal and inter annual variations in atmospheric O2 (detected through changes in O2/N2 ratio), which can aid in determining rates of marine biological productivity and ocean mixing. The results are also used to help determine the terrestrial and oceanic distribution of the global anthropogenic CO2 sink. The program involves air sampling at a network of sites in both the Northern and Southern Hemispheres. Palmer Station is especially well situated for resolving signals of carbon cycling in the Southern Ocean. Samples taken from the station are sent to Scripps where the analysis of O2 and CO2 content takes place. O-264-O COLLECTION OF ATMOSPHERIC AIR FOR THE NOAA\CMDL WORLDWIDE FLASK SAMPLING NETWORK David Hofmann, Principal Investigator, Climate Monitoring and Diagnostics Laboratory, National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (NOAA) Climate Monitoring and Diagnostics Laboratory continues its long-term measurements of carbon dioxide and other climate relevant atmospheric gases. The Palmer Station air samples are returned to the NOAA laboratory for analysis as part of NOAA's effort to determine and assess the long-term buildup of global pollutants in the atmosphere. Data from this experiment will be used in modeling studies to determine how the rate of change of these parameters affects climate. The station physician collected air samples weekly. O-275-O DOE-EML REMOTE ATMOSPHERIC MEASUREMENTS PROGRAM (RAMP) Colin Sanderson, Principal Investigator, Department of Homeland Security, Environmental Measurements Laboratory 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. One sample filter was exposed for the duration of each week, and a weekly schedule of calibration, background, and sample counts was maintained. The Research Associate operates and maintains on-site equipment for the project. On 01 October, the date on the RAMP sampling equipment (computer and MCA) was adjusted to 1992, in order to avoid further Y2K issues while keeping the leap year cycle in sync. On 10 October, the system clock was advance by one hour to account for Chile's (and Palmer's) shift to daylight savings time; this project keeps local time, not UT. O-283-P ANTARCTIC AUTOMATIC WEATHER STATIONS (AWS) Charles Stearns, Principal Investigator, University of Wisconsin The Research Associate monitors data transmissions for the project. AWS transmissions from Bonaparte Point, Hugo Island, and Racer Rock were monitored using the TeraScan system, with only Bonaparte Point currently operational. AWS data received was also forwarded to UCSB for B032P (Smith). A-306-P GLOBAL THUNDERSTORM ACTIVITY AND ITS EFFECTS ON THE RADIATION BELTS AND THE LOWER IONOSPHERE Umran Inan, Principal Investigator, Stanford University The Research Associate operates and maintains on-site equipment for the project. The Stanford equipment receives and records Very Low Frequency (VLF) radio waves in order to study natural ionosphere and magnetosphere phenomena, as well as to study the distribution of the lightning strikes that are a principle source of natural VLF signals. Broadband synoptic data was recorded on a schedule of three out of every 15 minutes each day, and broadband continuous data was recorded for at least six hours per day. Narrowband continuous data was collected for 12 hours each day. Personnel on station: Ryan Said, for annual site visit. During the annual site visit, which ran from 03 - 25 October: Data acquisition computers were reconfigured, with a fast new machine assuming the broadband continuous data collection, the former narrowband north-south computer taking over broadband synoptic duties, and the former synoptic machine performing narrowband acquisition from both antenna loops, running new software. All computers were equipped with 8X DVD+/-R/RW drives, large hard drives, and Windows XP. It is expected that operations will now be more reliable and user-friendly. Detailed analysis of the data and timing signals was performed to understand signal polarity and sampling timing. The antenna orientation was measured using real-time dGPS; this confirmed that very little shifted had occurred through the winter months. "Hum sniffing" noise measurements were collected at a variety of locations in the backyard and on the glacier. A multi-frequency system response calibration was performed. An initial assessment was performed on old equipment in the VLF hut, with some being discarded immediately, some identified for return to Stanford, and some set aside awaiting a determination from the grantees of whether the parts should be returned or disposed of at Palmer. Broadband continuous data was saved at a much higher rate, with as many as 18 of 24 hours each day being recorded, for a selected period of time. The same ship that brought the site visitor also brought a new supply of DVD-R discs, allowing the backlog of data files stored on hard drive to be burned. Enhanced whistler activity was observed several times outside the site-visit period, and extra DVDs were burned with broadband continuous data from these periods. T-312-O TERASCAN SATELLITE IMAGING SYSTEM Dan Lubin, Principal Investigator, Scripps Institution of Oceanography The Research Associate operates and maintains on-site equipment for the project. Throughout the month, the TeraScan system collected, archived, and processed DMSP, NOAA, and ORBVIEW-2 satellite telemetry, capturing approximately 25-30 passes per day. A weekly 85GHz SSM/I ice concentration image was produced and transferred to UCSB for B032P (Smith). Multiple ice images displaying the northern extent of the pack ice on the western side of the Antarctic Peninsula were provided to the R/V LAURENCE M. GOULD to assist in cruise operations for LMG04-11 and LMG04-12. An ice image showing a broader area west of the peninsula was provided to a grantee with B-013-P. Correspondence with the POC for cruise LMG04-14 led to the definition of an image footprint that will serve the needs of that cruise if ice is still in the area in December, and several images of that region were provided to the POC to be given to the grantees as they prepare for the cruise. After the seasonal switch of the DMSP satellites from high-resolution thermal to highresolution visible operation on 18 October, many F-13 passes appeared to contain a substantial number of dropped lines. After communication with the McMurdo TeraScan operator, it was concluded that the problem is probably due to the software ingestion routine provided by SeaSpace, and that it's been present, with varying degrees of severity, for the past several summers, in data collected at Palmer, McMurdo and on the R/V NATHANIEL B. PALMER. The McMurdo TeraScan operator will take the matter up with SeaSpace; in the meantime, F-13 passes will be scheduled sparingly, with heavier reliance on F-14 (despite its incomplete suite of special sensors) and F-15 (despite its higher noise level at low elevations). T-513-O ULTRAVIOLET SPECTRORADIOMETER NETWORK Charles Booth, Principal Investigator, Biospherical Instruments, Inc The Research Associate operates and maintains on-site equipment for the project. A BSI SUV100 UV spectroradiometer produces full sky irradiance spectra ranging from the atmospheric UV cutoff near 290nm up to 605nm, four times per hour, while the sun is above the horizon. A BSI GUV-511 filter radiometer, which has four channels in the UV and one channel in the visible for measuring Photosynthetically Active Radiation (PAR), is located next to the SUV100. Data from the GUV-511 instrument is made available on a daily basis on the project's website at http://www.biospherical.com/nsf. Scheduled absolute calibrations were performed on 09 and 25 October. A corrupted serial data transfer from the system's auxiliary-sensor digitizer on 17 October caused the UV Monitor to believe that it was overheating, which in turn caused it to abort data acquisition. The alarm condition was manually cleared to restart data collection after about ten hours of idleness. The Syquest data disk was changed on 20 October. At the regular daily GPS clock updating time on 22 October, the clock was erroneously set to 21 October, albeit to the proper time, causing data for the rest of the day to over-write data collected the previous day. The date was then set properly on 23 October. No explanation was determined for the occurrence. Twice this month, on 12 and 18 October, a serial port error prevented the GUV from opening its daily data file; manually stopping and restarting its data collection allowed the file to be opened. A somewhat increased rate of serial errors from the auxiliary-sensor system was experienced throughout the month, so at the end of the month the cabling was examined in search of loose connections (of which none were found). Disabling the link to the digitizer prior to this operation had the unexpected and unexplained effect of briefly disabled the removable Syquest disk on which data is recorded. After testing the Syquest and finding nothing wrong with it, recording was switched back over to it from the local hard drive, and the log file pieces that had accumulated in the different locations were manually unified. TIDE GAGE Tony Amos, Point of Contact, The University of Texas Marine Science Institute The Research Associate operates and maintains on-site equipment for the project. Tide height, seawater temperature, and salinity are monitored on a continual basis by a gage mounted at the Palmer Station pier. During snow removal operations on 02 October, heavy equipment accidentally severed the tide gage's communications cable and the conduit protecting it. A temporary cable splice was performed to restore operations with minimal (less than two hours) data loss; a more permanent repair will be done after the snow melts. In a reprise of a problem encountered in May, the tide gage acquisition computer mysteriously slipped into a twelve-minute sampling mode on 14 October. Rebooting it restored proper two-minute interval sampling, but almost a full day of data was affected. METEOROLOGY The Research Associate acts as chief weather observer, and compiles and distributes meteorological data. At the end of the month a summary report is prepared and sent to interested parties. Weather data collected using the automated electronic system is archived locally and forwarded semimonthly to the University of Wisconsin for archiving and further distribution. Synoptic reports are automatically generated every six hours by the Palmer Meteorological Observing System (PalMOS) and emailed to the NOAA for entry into the Global Telecommunications System (GTS). Current weather observations for all Antarctic stations, including Palmer, are available on the web at: http://www.wunderground.com/global/AA.html. An engineer from Coastal Environmental, the vendor of the automated PalMOS weather station, was on station from 03 - 08 October for a site visit. During this visit: The malfunctioning present weather sensor was replaced. Several changes were made to the Zeno data-logger program, most significantly a switch from one-minute to two-minute sampling intervals. It was determined that the previously reported ceilometer's problems were actually a result of a serial-port conflict in the data logger, which disappeared when the acquisition program was set to passive "listening" mode instead of active "polling"mode. The ceilometer was removed and sent north to be fitted with a blower to allow it to operate better in the rain and snow. Reporting of a flag for large values of "sigma-theta" an indication of short-term variability of wind direction, was enabled. Alternate locations for placement of the optical sensors were evaluated. Shortly after the conclusion of the site visit, it was noted that the visibility sensor readings were stuck on a single value. Investigation showed that the problem was in the data logger, not the sensor, and resetting the data logger restored normal operation, at least for a few hours. Changing various acquisition program settings did not prevent the problem from reappearing, so the reporting of visibility data in the synoptic messages was disabled while investigation continued. Adjusting the number of sampling attempts on various serial sensors had a clear impact on the frequency with which the problem occurred, and eventually a configuration was reached in which the problem disappeared, at which point synoptic visibility reporting was re-enabled. A new version of the synoptic reporting program PS-RG that allows for manual editing of the synoptic messages prior to their transmission was received and installed. A single manual cloud coverage observation is now being performed daily at 1800 UT, with the observed condition then being manually edited into the synoptic message; this will continue until the ceilometer returns and is reinstalled or until its deemed that the information provided by such an observation is unnecessary. A visibility "calibration" was performed on the WIVis present weather sensor after it was increasingly reporting limited visibility and "fog" in clear-air conditions.