New Zealand Prepared by: Nancy Bertler
email: nancy.bertler at vuw.ac.nz
Meteorological observations, snow pack temperature flux and radiation balance (incoming and outgoing) were recorded at Victoria Lower Glacier and Baldwin Valley Glacier during two seasons 1999/2000 and 2000/2001. The data are used to link the longer AWS weather records from Scott Base, Marble Point, and Lake Vida with weather pattern at Victoria Lower Glacier to establish transfer functions for our ice core data.
Analytical Measurements
Snow samples, ice cores and dust from the McMurdo Dry Valleys were shipped to Victoria University (NZ) and University of Maine (US). Physical properties of the ice, dust content, flux and mineralogy, diatom concentration and tephra analysis were conducted at Victoria University. Major ion (Na, Mg, Ca, K, NH4, Cl, NO3, and SO4), MS (methane sulfonate), trace elements (Al, Fe, Cu, P, Mn, Sr, Si, and Zn), and isotopic ratios (δ18O and δD) on the water were analysed in collaboration with Prof. Paul Mayewski and Dr. Karl Kreutz at University of Maine.
Major ion concentrations were measured for cations (Na+, K+, Mg2+, Ca2+) using DionexTM ion chromatography with Dionex CS12 column and 20 mM methanesulfonic acid eluant. Anion concentrations (Cl-, NO3-, SO4=) were measured with a Dionex AS11 column, 6.0 mM NaOH eluant. For both measurements a 0.25 mL sample loop was used. Methane sulfonate (MS) content was measured using a Dionex AS11 column with 0.1 mM NaOH eluant and a 1.60 mL sample loop (Sneed, pers. communication 2001, 2002). Control samples of frozen, ultra pure water (18meg? Millipore® water) showed that no significant contamination occurred during sampling and processing of the glacial material. Sample duplicates showed good reproducibility within 3% (n=213) and 10% (n=46) for low concentration (1-10ppb) samples.
Trace elements were measured using a Perkin-Elmer Optima 3000 XL axial inductively coupled plasma optical emission spectroscopy with a CETAC ultrasonic nebuliser (ICP-OES-USN). Rubidium was used as an internal standard for sodium and yttrium for all other elements (Handley, pers. communication 2001, 2002). External quality control samples, run every ten samples, showed that the reproducibility was for most species within <5% (n=130), with the exception of Fe and Mg within <10% (n=130).
Samples were analysed for stable hydrogen isotope radios δD via Cr reduction with a Helium continuous flow Eurovector elemental analyser coupled to a Micromass® Isoprime mass spectrometer. Oxygen isotope ratios were measured using a CO2 dual-inlet system coupled to a Micromass® Isoprime mass spectrometer (Introne, pers. communication 2001, 2002). Sample duplicates and standard measurements showed a precision 0.08‰ (Kreutz, pers. communication, 2002).
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