In 1997 a 121 m ice core was retrieved from Lomonosovfonna, the highest ice field in Spitsbergen, Svalbard (1250 m a.s.l.). Radar measurements indicate an ice depth of 126.5 m, and borehole temperature measurements show that the ice is below the melting point, High-resolution sampling of major ions, oxygen isotopes and deuterium has been performed on the core, and the results from the uppermost 36 rn suggest that quasi-annual signals are preserved. The 1963 radioactive layer is situated at 18.5-18.95 m, giving a mean annual accumulation of 0.36 m we. for the period 1963-96. The upper 36 rn of the ice core was dated back to 1920 by counting layers provided by the seasonal variations of the ions in addition to using a constant accumulation rate, with thinning by pure shear according to Nye (1963). The stratigraphy does not seem to have been obliterated by meltwater percolation, in contrast to most previous core sites on Svalbard. The anthropogenic influence on the Svalbard environment is illustrated by increased levels of sulphate, nitrate and acidity. Both nitrate and sulphate levels started to increase in the late 1940s, remained high until the late 1980s and have decreased during the last 15 years. The records of delta O-18, MSA (methanesulphonic acid), and melt features along the core agree with the temperature record from Longycarbyen and the sea-ice record from the Barents Sea at a multi-year resolution, suggesting that this ice core reflects local climatic conditions.

Detailed chemical analysis of the 122 in, relatively high-altitude and low-melt Lomonosovfonna ice core provides the best-dated record of nitrate from Svalbard. A very significant non-linear trend present in the record shows: (a) a rise in concentrations from the 12th to the mid-16th century, (b) reasonably stable concentrations until the mid-19th century, (c) a rise in concentrations into the 20th century, with (d) a rapid rise in the 1950s and (e) a decrease after the mid-1980s. Nitrate is well correlated with ammonium before 1920 and after 1960 but not in the intervening period. The correlation between ammonium and nitrate concentrations indicates that ammonium nitrate (NH(4)NO(3)) has been common at Lomonosovfonna. There are also places in the core where nitrate is very closely associated with calcium.

We present a high-resolution record of water-soluble ion chemistry from a 121 m ice core spanning about 800 years. The core is well dated to 2/3 depth using cycle counting and reference horizons and a simple but close fitting model for the lower 1/3 of the core. This core suffers from modest seasonal melt, and so we present concentration data in decadal running means to minimize percolation effects. Sea-salt ions (Na+, Cl-, Mg2+, and K+) account for more than 70% of all ions. In general, sea-salt ion concentrations are rather variable and have no clear association with climatic variations. Sulfate, with 74% being from non-sea-salt sources, has higher concentrations than seen on Vestfonna ice cap but lower than in Ny-angstrom lesund aerosols, suggesting central Spitsbergen receives more marine (westerly) air masses than Ny-angstrom lesund but more sulfate enriched (easterly) air masses than Nordaustlandet. Clear anthropogenic impacts are found for sulfate, nitrate, and ammonium (and probably excess chloride) after the mid twentieth century, with sulfate showing a significant rise by the end of the nineteenth century. Sulfate and methanesulfonate concentrations correlate well during the twentieth century, and it is clear that most of the preindustrial sulfate is of biogenic origin. Terrestrial component (Ca2+) has the highest concentrations in the coldest part of the Little Ice Age, suggesting more windy conditions, transporting local terrestrial dust to the ice cap. All ion concentrations decrease at the end of the twentieth century, which reflects loss of ions by runoff, with non-sea-salt magnesium being particularly sensitive to melting.

A medium-length ice core was drilled at the ice divide oil the Lomorlosov-fonna plateau (1230 in a.s.l.), Svalbard, in May 1997. As part of this project, temperature measurements were performed in the 120 in deep borehole. At this site the ice thickness based oil radar measurements is 126.5 m and the mean annual accumulation rate is 380 kg m(-3). The measurements over the 15-120 in depth interval show a nearly isothermal profile with a mean value of -2.8degreesC and a standard deviation of 0.2degreesC. The measurements reveal a temperature minimum at approximately 70 in depth and a temperature gradient of 0.011 +/- 0.004degreesC m(-1) near the bottom. The temperature minimum and relatively low temperature gradient cannot be explained in terms of a steady-state climate. Numerical calculations with a simple one-dimensional diffusion-advection model show that the temperature increased at a maximum rate of 0.02-0.025 Ka(-1) over the last 100 years, the total temperature increase amounting to 2.0-3.0 K. Forcing the model with the observed record at Svalbard airport revealed that In the 19th century the surface temperature was at most 2.5 K lower, and that the instrumental observations started during a period with temperatures comparable to the end of the 19th century. The data are of particular interest for historical simulations since often no other temperature data are available in polar areas.