Heat, water vapor and momentum exchanges at the Dasan Station in Ny-Alesund, Svalbard, the Arctic

Abstract

The four potential feedbacks between the impacts of climate change on the Arctic and the global climate systems have identified as follows based on the Paleoclimate studies and the contemporary Arctic ones (Terry et al., 2004): 1) albedo, 2) greenhouse gas emissions and/or uptake through biological response to warming, 3) greenhouse gas emissions from methane hydrates released from thawing permafrost and 4) increased freshwater fluxes that could affect thermohaline circulations. The Ny-Alesund science town in Svalbard, Norway is suitable for the researches related with the feedbacks due to its north most location (~79N), where anthropogenic effects may be minimized. Turbulent fluxes of sensible heat, water vapor and CO2 have been measured at a semi-desert of Ny-Alesund since summer of 2003. These data can be used to better understand 1) the thermal properties at the active layer and the permafrost, 2) the response of polar ecosystem to the environmental changes, and 3) the impact of atmospheric boundary layer on the aerosol formation. Due to system failure and weak but frequent rain event, flux data retrieval rate was not so high but data was available to evaluate and compare turbulent exchanges of heat and water vapor at the site for four summer seasons. Based on the preliminary results, the magnitudes of evaporative fraction and ground heat flux were similar to the results reported previously near our site. However, energy imbalance was relatively larger and changed with wind direction. The effects of different averaging time and coordinate rotation on turbulent fluxes were not significant. Concomitant measurements at two heights did not make any significant difference in turbulent fluxes. Additional analyses will be made and reported in detail at the presentation. This study was supported by &#47703

ntegrated research on the Composition of Polar Atmosphere and Climate Change (COMPAC)?(PE07030 of Korea Polar Research Institute).