Palmer Station Science Monitoring Programs
There are a variety of science programs housed at Palmer Station that are long term monitoring programs dealing with topics far afield from whales, penguins, macroalgae or krill. In order to gather information on a long term basis, research agencies enlist the assistance of a “science technician” to ensure that the instruments are functioning, can be repaired when necessary, and to ensure that the data being collected is sent back to the user institutions. Palmer Station is proud to be home to such a science technician. Too shy to share his name he is nonetheless brimming with enthusiasm about the coming year he will spend ably assisting in these monitoring programs. Below is a brief overview of the variety of science monitoring programs underway here at Palmer Station, many of which date back to the late 1970’s or early 1980’s.
The “Weather Room”
This little room in Palmer Station is brimming with instruments. The new digital weather system installed in the past several years replaces an older system that relied on humans to collect information. For example the old system required that a technician make manual observations of air temperature every 6 hours, place a plastic bucket outside to gather and measure precipitation, and use paper strip recordings to decipher wind speed from an anemometer (a windmill like instrument). The downside of these types of measurements is that it is almost impossible to prevent periodic human error. The new digital weather system is more accurate and has essentially eliminated human error as well as the need to have someone check instruments regularly to take measurements. But at the same time it is susceptible to power outages and when expensive parts break there can be delays of weeks or months to have new replacement parts shipped down. Weather observation is important here. For example, our research team uses this information to make decisions about the safety of going out to dive from small boats. And when winds reach a sustained 25 knots, the station leader announces that nobody is allowed to go out in a boat period!
Also in the weather room is the tidal gauge that measures daily shifts in local tidal height. The way it works is there is a pipe hung off the pier with two sensors inside it, one that measures conductivity and temperature, and another that measures temperature and pressure. From the temperature and conductivity it is possible to calculate the salinity of the sea water, and if you know the salinity and the sea water temperature you can figure out the density of the sea water. Density and pressure information then yields a measure of depth, and it is through this parameter than one can determine the tidal flux. It turns out that here at Palmer Station we experience about a 2 meter tidal cycle over a lunar cycle. The tide level is important information if you are the captain of a visiting ship wishing to tie up at our dock, and it may also impact the ability of our sea water intake pipe to pump water into our aquaria housing our marine organisms.
Surface Air Sampling Program
The Department of Energy oversees this program that tracks radionucleotides at the level of the surface of the earth. For those not familiar with a “radionucleotide” it is a radioactive particle that gives off a gamma ray when it decays. The radio nucleotides are captured on filters that process air for a period of one week. At the end of the week the filter is placed inside a gamma ray counter and this produces a spectrum that allows one to measure radiation. The only radionucleotide that shows up happens to be called beryllium 7, which has a half life of only 53 days. It is produced when cosmic rays (high energy particles) encounter our atmosphere and break down atoms. Scientists can use the information about changes in the levels of beryllium 7 to better understand patterns of atmospheric mixing.
The United States Geological Service oversees this very sophisticated version of a hand held Global Positioning device. At a cost of about $60,000 it has a very precise internal clock and tuning and processing capability. The instrument is used to pin point the locations of about 12 satellites in polar orbits. This information is an important part of a federal program that has land-based stations positioned all over the globe that assist in tracking the exact position of satellites that provide a network for GPS capability. The GPS installation at the South Pole is especially critical because there is not another station for 850 miles. The instrument here at Palmer Station can also make position determinations to a scale of 2-3 centimeters! Thus when penguin biologists want to use aerial photographs to track the dimensions of penguin colonies over periods of years, or glaciologists want to track the recession of a nearby glacier, this is feasible with very high accuracy.
The United States Geological Service also runs this device which measures seismic activity. There are three sensors attached to the surface of a block of concrete and housed in a small shed that record the earth’s seismic activity. Antarctica is an extremely quiet continent in terms of earthquakes, with most being recorded from the sea floor surrounding the continent. However, this instrument can detect and provide information about earthquakes on or near other continents, especially quakes that are 5 or greater on the Richter scale.
Ultraviolet Radiation Monitoring Instrument
When the famous hole in the ozone over Antarctica was detected in the early 1980’s it became important that instruments be placed around the continent to monitor its size and dynamics. The good news is that the hole is not getting bigger, the bad news is that it is not getting any smaller. This instrument senses UV radiation every 15 minutes when the sun is up. It scans a spectrum of 280-605 nanometers. The harmful radiation (UV-B) falls between the wave lengths of 280-320 nanometers. When the hole in the ozone is at its maximum size during the summer months, the levels of harmful radiation reaching the earth in Antarctica increase greatly.
The National Science Foundation uses this instrument to track polar orbiting satellites and to collect imagery in the infrared, visible and microwave spectra. These images are important to those studying polar meteorology and also to those scientists who track patterns of sea ice coverage and break-up in Antarctica. Moreover, images of sea ice cover are often sent to ships to allow the captain to make informed decisions about how to best plan out a cruise track within a region with sea ice.
VLF Antenna and Receiver
Stanford University uses this instrument to measure very low frequency (VLF) radio waves. These wavelengths are in the frequency of 100-100,000 hertz. Because human hearing overlaps with these wavelengths (20-20,000 hertz) it is possible to amplify these radio waves and listen to them! They sound likes cracks, pops, whistles and even flocks of birds. The radio waves that one hears are actually lightning strikes occurring somewhere on the planet (definitely not Antarctica!). The radio waves created by the lightning bounce back and forth from the earth’s surface to both the ionosphere and magnetosphere. Atmospheric physicists can use this information to learn about the properties of these layers of the atmosphere. Moreover, climatologists can use the radio waves created by lightening strikes to tell them when and where the strikes occur and thus to study global storm systems.