New and On-going Arctic Research at Nevada s Desert

New and On-going Arctic Research at Nevada’s Desert Research Institute 1. Chemical fluxes from a moist tundra ecosystem 2. Ground-based remote sensing of ice-crystal properties in cirrus clouds 3. Automated ultra-trace chemistry of ice cores 4. Testing of luminescence methods for dating Arctic Ocean sediments

A Tundra Isoprene Study at Imnaviat Creek near the Toolik Field Station (NSF-Atmos-Chemistry & NSF-OPP SGER grant to Mark • Tundra ecosystems emit significant amounts of isoprene • Isoprene emissions (though a minor component of tundra carbon dynamics) in the ‘clean’ arctic atmosphere have a major impact on atmospheric chemistry • Data will impact models of Arctic tropospheric chemistry Potosnak)

Measuring Small (< 60 mm) Ice Crystal Concentrations in Arctic Cirrus Clouds (DOE-ARM grant to co-PI David Mitchell) Project will use remote sensing (radiance interferometer, Lidar, local sounding) to estimate optical properties and heat emitted by cirrus clouds • Cirrus clouds may have a strong feedback to temperature forcing by greenhouse gases • This feedback can be +ve or –ve, and depends on the concentrations of small ice crystals in the particle size distribution

Ultra-trace Chemistry from Greenland Ice Cores (NSF-OPP & DRI grants to Ross • • Edwards) Analytical Systems: an ultra-trace, metal, clean, continuous ice-core melter, a low-level continuous-flow Fe-analysis system, 2 high-resolution ICP-MS units, a super-sensitive analytical system for measuring black carbon in ice-core meltwater Project Questions: 1. Has atmospheric Fe become more soluble during the industrial period because of pollution? 2. What has been the impact of boreal forest fires and industrial pollution on the availability of Fe and P?

Developing Small-sample Luminescence Dating Procedures for Arctic Ocean Sediment Cores (NSF-OPP grant to Glenn Using samples of cores from the HOTRAX-05 expeditions Berger)