Jan. 28, 1999
Letter 10: The Dark Sector
The United States, a leader in the establishment of the Antarctic Treaty that was originally signed by 12 nations and came into force in 1961, continues to play a significant role in the treaty's success. The current 42 treaty members forbid military actions and are dedicated to peaceful activities in Antarctica including scientific research and the encouragement of international collaboration. At our briefing by the ASA (Antarctic Support Associates) Director of Science Support in Denver at our Oct. 24th orientation, we learned that there would be 30 science events at the South Pole Station this austral summer involving at various times approximately 130 scientists. Due to logistics and the size of our station, only 50 scientists would be here at any one time. They would be coming from Australia, the United Kingdom, Germany, Spain, Japan, Italy, Sweden, and, of course, the United States. Over various years, science at the South Pole Station has included astronomy and astrophysics, auroral and radio-science studies, meteorology, geomagnetism, earth-tide measurements, seismology, glaciology and biomedical studies.
Because some of the scientists prefer working late into the daylight of our "night" shift when it is a less crowded and hectic time of day, I had the good fortune to meet Roo one evening when I was having my bowl of cereal and tea before going to work at 10 p.m. In our conversation, I boldly asked Roo for a tour of his science event at the Dark Sector, as I'd desperately wanted a personal tour since I'd arrived in November. He was delighted to oblige and even offered to talk to Charlie and others to see if he could have other scientists available to talk about their projects, too, while I was there. We set the date for Jan. 16, Saturday evening, at 8 p.m. because I'd have an extra hour before going to work (I start work 1 hour later on Saturday and work 2 hours longer Sunday morning). On the 16th, I set my alarm clock earlier than usual and was off to meet Roo in the galley before heading from the dome across the aircraft taxiway, straight through the Ceremonial South Pole, across the skiway and onto the hard packed snow trail to the Dark Sector over 1 km from the dome entrance. Although it isn't dark there or anywhere here during austral summer, it is called the Dark Sector because it is restricted ("dark") of radio emissions due to sensitive equipment for scientific events occurring in the area.
Roopesh Ojha, AST/RO project.
Photo by Sandi Kolb.
Dr. Roopesh (Roo) Ojha, post doc fellow at Harvard Smithsonian Center of Astrophysics, and winter-over scientist for the Antarctic Submillimeter Telescope and Remote Observatory (we call it AST/RO) is extremely arcticulate and always ready for conversation interspersed with humor. Roo first lead us to the roof of the AST/RO building to see the main dish (a mirror of 1.7 meters in diameter) of the AST/RO telescope. From the roof-top discussion and view of the telescope, Roo guided us down an outside staircase with incredible panoramas of the station in one direction and infinity in another, then inside the building to the AST/RO control room and receiver room where the light collected by the main mirror on the roof enters the telescope. Interestingly the AST/RO telescope has a minimum of equipment outside. Gradually we found some chairs in a cluttered office area and settled in for an engaging discussion of AST/RO's survey of interstellar gas in support of the Big Bang expansion of the universe. Acoustics at the time of the Big Bang resulted in the formation of parcticles of Cosmic Microwave Background Radiation (CMBR) that can be observed. AST/RO is establishing an understanding of the interrelation of galactic dynamics and the creation of stars. AST/RO concentrates mainly on the molecular clouds created by stars of several generations past and the molecular clouds where stars are born. Because carbon is one of the few elements that can be observed in all of its phases, AST/RO is monitoring its signals for indications of stellar activity. The lowest frequency that AST/RO observes is at 230 gigahertz with the highest being 810 gigahertz. The best submillimeter telescope conditions on earth are at the South Pole with the single most important factor for AST/RO being our low humidity. Since moisture absorbs radiation and produces and scatters sky noise as well as blocks signals, our exceptionally low humidity provides the most transparent site for this observatory. AST/RO works with long wavelengths (the objects are cooler). Nearing the close of our time with Roo, he leaned back in his chair and with a grin creeping across his face said, "Really we are just studying stellar recycling-how stars die and are born. We're stellar pediatricians." For further information see: http://cfa-www.harvard.edu/~adair/AST_RO.
Charles (Charlie) Kaminski, on Sabbatical from the University of Hawaii and now working for the Center for Astrophysical Research in Antarctica (for CARA go to: http://astro.uchicago.edu/cara/) with the University of Chicago and only on Jan. 24th honored with the title of Senior Winter-Over Science Leader for the South Pole, took over the next portion of our Dark Sector tour. Roo joined us as Charlie led the way to the second and larger building, the blue elevated space-age looking Martin A. Pomerantz Observatory (MAPO) that houses the SPIREX and VIPER telescopes. Charlie is with the Abu/SPIREX (The National Optical Astronomy Observatories infrared camera, Abu, on the South Pole InfraRed Explorer telescope) science project. This scientific system is a joint project of CARA at the U. of Chicago, the National Optical Astronomy Observatories (NOAO) in Tucson, Arizona, the U. of New South Wales (UNSW) in Australia and the Rochester Institute of Technology (RIT) in New York. Like Roo, Charlie, directed us first to the roof to admire SPIREX and explain its components. Two years ago Les and I viewed Venus from this telescope on a bright and sunny Antarctic day (it doesn't need to be dark). Once chilled to the bone, Charlie took us inside to find some stools and chairs among computers and technological litter to discuss Abu/SPIREX. Charlie, who is usually quiet and somewhat reserved, obviously delighted in talking to us about his science event. SPIREX is a normal optical telescope that functions in the near infrared and produces more energetic transmissions in shorter and warmer wavelengths than AST/RO. Abu, the camera, uses an Aladdin focal plane array that is a thermal infrared detector. This camera was named Abu for Aladdin's monkey who was a thief, because the scientist who designed it gathered bits and pieces of technology from a wide range of laboratories. By means of using the infrared, the Abu/SPIREX project is able to observe the thermal emissions of thick interstellar clouds, new star formations and nearby galaxies. As the universe is expanding, objects that are far away are more visible in the near infrared. With the Abu and SPIREX teaming together, imaging of wavelengths at 3-5 microns opens the way for what is called wide-field astronomical observations. Charlie asked us, "Why is there astronomy at the South Pole?" and then proceeded to define the 3 conditions best for all astronomical studies: low humidity, low temperatures and atmospheric stability (aided by elevation). Because stars don't set at the South Pole, Charlie went on to add, they can be observed for extended periods of time. For Charlie Kaminski's web site find: http://irtf.ifa.hawaii.edu/~kaminski/kaminski.html and scroll and click on Antarctica. On Jan. 10th, I attended the spirited science lecture, "Abu/SPIREX," by Drs. Nigel Sharp and Al Fowler who captivated a full house galley audience with their enthusiasm, energy and humor. Nigel gave me this web site address for the National Optical Astronomy Observatories: http://www.noao.edu. For further information on Abu/SPIREX go to: http://astro.uchicago.edu/cara/research/ir/spirexabu.html.
John Davis, Roo Ojha, Greg Griffin and Charlie Kaminski
Photo by Sandi Kolb.
The last stop on our tour was to see the Viper telescope (some time ago it was a fad to name our telescopes after snakes), but first we were fortunate to find Greg Griffin, a graduate student at Carnegie-Mellon and the winter-over Viper scientist, in the Viper control room. Greg joined our little group as we went outside to view this submillimeter telescope from 3 different floor levels and ended up on MAPO's roof. Viper is a 2.1 meter telescope created for wavelengths from 10 mm to 0.3 mm and weighs 8,000 lbs. Viper has a total of 4 mirrors in a system that gathers microwave radiation from the sky in a collecting mirror to a 40 gigahertz receiver and back out again. The Viper is a Cosmic Microwave Background Radiation (CMBR) scientific event and is the first such telescope to measure cosmic background objects in the sky. On Jan. 27th, I attended the evening science lecture; "Do We Live in a Flat Universe? Recent Results from Viper", given by Dr. Jeff Peterson of Carnegie-Mellon University and the Principal Investigator (P.I.) of the Viper project. Jeff has the valuable talent of being able to explain highly technical matters to a diverse audience in a patient, organized and arcticulate manner. Only around Thanksgiving time, Jeff presented the first results of Viper data to a world conference in Paris. Viper, the first telescope to measure the size of cosmic background objects, measures temperatures of the young universe at 300,000 years after the start of the Big Bang. The data indicates that the measured size of about half a degree is the predicted size if the cosmological model is flat. This tells us that the Big Bang was forceful enough to perpetually expand the universe. This means that the most distant galaxies are moving away from us faster than the nearer ones (the Hubble Expansion of the universe) and that 12 billion years ago everything was at highest density causing the collapse of the universe (the Big Bang). The Inflation Theory is supported and the Hubble Expansion will never reverse (the universe will become colder). As Greg explained it, Viper is observing the afterglow of the Big Bang. Once we came in from the cold to warm up in the Viper control room, John Davis, the winter-over CARA (Center for Astrophysical Research in Antarctica) machinist/instrument builder joined the group. All 4 of the winter-over CARA personnel were together (Roo, Charlie, Greg and John) so we unanimously decided it was group photo time. Just before I snapped the photo, I caught Greg through my camera lens holding up a dangling grotesque elongated rubber chicken by the neck. I thought, "Oh, well, yet another example of South Pole humor" and clicked the camera. Les and I have had many entertaining breakfast conversations with Jeff Peterson and when I discovered he was a word puzzle fan, the 3 of us periodically join forces to work on the Times Fax crossword. Jeff gave me this web site address to share with you: http://cmbr.phys.cmu.edu. Click on the photo of Viper to bring up a menu of options.
Jeff Peterson (P.I. of Viper project) and Sandi.
Photo by Les Kolb.
Also located in the Dark Sector is a small bright green and gold building housing the AASTO (Automated Astrophysical Site-Testing Observatory) that is patterned after the U.S. AGO (Automated Geophysical Observatory). AASTO is a joint U.S. and Australian project, JACARA (Joint Australian Center for Astrophysical Research in Antarctica), funded out of the U. of New South Wales in Sidney. On Jan. 17th, I attended a lecture entitled "Antarctic Astronomy" by Dr. Michael Burton of the U. of New South Wales and learned about the AASTO scientific event. AASTOs are powered from propane, are self-heated and require only 50 watts of power to take the data. The primary advantages of this observatory are that it fits assembled into a Herc (LC130) for the efficient establishment of remote sites and that it can operate automatically for up to 12 months at a time. Instruments inside the AASTO are near and mid-infrared sky monitors and an Antarctic fiber optic spectrometer including instruments that continually monitor wind speed, wind direction, air pressure and temperature. This season AASTO is also operating SODAR (acoustic radar) to determine the exact amount of turbulence in the surface boundary layer of the atmosphere. As we approached the AASTO building we could hear the audible chirps of the SODAR as signals were sent to reflect off the atmosphere's surface boundary layer for measuring and recording turbulence. SODAR has a range of 600 meters. At the close of his lecture, Michael Burton gave us the following web site addresses. For AASTO's home page: http://www.phys.unsw.edu.au/~mcba/aasto.html; for JACARA's web site: http://www.phys.unsw.edu.au/~mgb/jacara.html; and for the AASTO web camera: http://bat.phys.unsw.edu.au/~aasto/.
The AMANDA (Antarctic Muon and Neutrino Detector Array) project is headquartered on the end of the second floor of the MAPO building and is a dense maze of colorful cables dangling from control panels and computers. AMANDA is a collaboration of more than 60 people coming from Germany, Sweden, Belgium and the United States and uses high-energy neutrino astronomy to map the skies of the Northern Hemisphere. From this data and further extended studies a new map of the universe can be shaped. As high energy neutrinos pass through the earth, they collide with nuclei to create a high energy muon. The earth is a filter to detect these authentic muons coming from neutrinos as they pass upward from the S. Pole. When muons travel through ice, they slow down and create a sonic boom effect resulting in the creation of a purple light (the speed of light in ice is 2/3 of what it is in a vacuum). Since neutrinos hold their course, these flashes of light from muons depict the celestial origin of the neutrino if the path is reversed. AMANDA is sinking 50 photo-multiplier telescopes (sealed in heavy round glass bulbs) in a string to depths of 1,500 to 2,000 meters down into the ice. There are now around 400 of these sensors in the ice retrieving about 5 gigabytes of data per day. These light-sensing detectors can last indefinitely and have only about a 3% failure rate. Neutrino astronomy must be done where the material is transparent making the South Pole the ideal location with its largest and cleanest material, ice, available. Nik Starinsky, the winter-over researcher with AMANDA, is a soft-spoken and engaging conversationalist who is always excited to discuss his project. Nik says that finding the obscure neutrinos is like watching the sky for asteroids and not blinking in order to not miss this most beautiful event. On Jan. 24th, Dr. Steve Barwick, U. of California at Irvine, gave the science lecture "AMANDA: Probing the Frontiers of Parcticle Astrophysics" to a full galley audience. If you would like further information, Steve shared this address with us: http://amanda.berkeley.edu/.
Tonight (Feb. 4) we are in the midst of another Antarctic storm. When I walked to the dome to work this evening I couldn't see the colorful flags surrounding the Ceremonial South Pole nor the Dark Sector. Winds were gusting to 28 knots with visibility at 400 meters as I leaned into the headwinds of rolling waves of white powder stopping periodically for a rest and to admire the tremendous beauty of this frigid Antarctic storm. A C130 circled unseen and unheard at 20-24,000 feet for about 2 hours before returning to McMurdo with the mission being aborted. As I walked through the dome to the Communications building, I heard what we call "dome thunder" which is caused by the winds shuddering the dome. There's the feeling of winter quickly approaching as temperatures are dropping and we are wearing more ECW clothing for our walk to and from the dome. I've been seeing more polar fleece jackets over other layers for inside dressing lately. I shivered in my turtleneck and denim shirt as I ate my midrats dinner in the galley tonight. As I sit here, I've also added my polar fleece jacket to the layers and I'm thinking I'll trade my sports shoes and cotton socks for my hiking boots, polypro sock liners and wool socks for inside wear tomorrow. The Amundsen-Scott South Pole Station winter closing date Feb. 15th. At that point, only the 43 winter-over personnel will remain unsupported (no flights due to the long winter night and extremely cold and severe weather conditions) until mid-October when the first flights arrive in preparation for the next austral summer season station opening.
Les and I are scheduled to redeploy on Feb. 13th to McMurdo and then out of Antarctica to Christchurch, New Zealand on the 14th. It could be a memorable Valentine's Day squashed in a C141 for 5 hours eating those shredded white cheese and chunky pineapple sandwiches, if we're lucky. If we're not, we could be on the LC130 for 8 hours and still have those famous sandwiches! This is all, of course, weather permitting. Two austral summers ago, we were detained in McMurdo for 3 nights and flew at midnight on our last day into our first night in 3 ½ months. I was fortunate to be seated near a tiny window and peered at the gorgeous sunset, the night and the aurora australis for what seemed like hours. It was another "moment in time;" one of many on this awesome continent.
The climate summary for the month of January written by two of our station meteorologists, Dar and John, follows.
amateur radio: NE7V
SOUTH POLE STATION ANTARCTICA. JANUARY 1999 CLIMATE SUMMARY. Temperature: Avg temp................ -26.5(C)/-15.7(F) Departure from normal... +1.6(C)/+2.9(F) Max temp................ -19.2(C)/-2.6(F) on day 21 Min temp................ -35(C)/-31.0(F) on day 31 Sky cover: Avg cloud cover (8ths).... 04 Days clear................ 11 Days partly cloudy........ 05 Days cloudy............... 15 Wind: Avg wind speed............ 9.5 mph or 8.2 kts. Prevailing wind direction..grid north or 360 degrees. Max wind.................. 37 mph or 32 kts on day 21 Max wind direction........ grid north. Avg vectored wind......... 021 degrees at 6.9 knots. Station pressure: Avg pressure........... 691.9 mbs or 20.432 In. Hg. Departure from normal.. +1.9 mbs or +0.056 In. Hg. Highest pressure....... 704.5 mbs or 20.804 In. Hg. on day 20 Lowest pressure........ 681.6 mbs or 20.128 In. Hg. on day 10 Sunshine: Sunset on 21 March, Sunrise on 23 September Average hours/day........ 19.0 Percent of possible...... 79% Snowfall..... trace; avg net change at snow stakes +0.935 inches. Visibility... 2 days with visibility of 1/4 mile or less. Balloon flight data: Number of Soundings for the month... 61 Avg height of Soundings.... 23.3 mbs or 30903 meters above msl. Highest Sounding........... 4.3 mbs or 38394 meters above msl. on the day 2/00z Sounding. Remarks: 1 Sounding was missed. 55 Soundings were terminated above 50 mbs. 2 Soundings were terminated between 50 and 100 mbs. 4 Soundings were terminated below 100 mbs. Records: Day 21 - A maximum temperature of -19.2(C)/-2.6(F) broke the previous record high for the day of -20.2(C)/-4.4(F) set in 1985. Day 21 - A peak wind gust of 32 kts/37 mph broke the previous peak wind record of 29 kts/33 mph set in 1957. Day 21 - The average wind speed of 20.8 kts/24.0 mph broke the previous record of 18.4 kts/21.2 mph set in 1972. Day 22 - The maximum temperature of -20.1(C)/-4.2(F) broke the previous record high for the day of -20.4(C)/-4.7(F) set in 1981. Prepared by: Dar Gibson/John Gallagher Sandra Kolb Amundsen-Scott South Pole Station