Abstract: The ABLE missions have been designed specifically to study the rate of exchange of material between the Earth's surface and its atmospheric boundary layer, and the processes by which gases and aerosols are moved between the boundary layer and the 'free' troposphere. These expeditions are conducted in ecosystems of the world that are known to exert a major influence ... on global atmospheric chemistry. In some cases, these ecosystems are undergoing profound changes as a consequence of natural processes and/or human impact.ABLE 3A is a component of the NASA Global Tropospheric Experiment (GTE) sponsored by the NASA Tropospheric Chemistry Program.
The Arctic Boundary Layer Expedition (ABLE 3A) was conducted in Arctic and sub-Arctic regions of North America and Greenland during July and August 1988. ABLE 3A was the first comprehensive investigation of the sources, sinks, and distribution of trace gas and aerosol chemical species in a northern high-latitude region during summer months. The ABLE 3A experimental design placed emphasis on the role of biosphere-atmosphere interactions in determining the chemical composition of the troposphere and on processes which influence the tropospheric ozone budget. The suite of chemical species measured included the following gases: methane, carbon monoxide, carbon dioxide, total "reactive" nitrogen gas, nitric acid, peroxyacetyl nitrate, peroxypropionyl nitrate, ozone, and aerosol chemical composition and size distribution. The instruments used included a capacitive sensor, chilled mirror, Differential Absorption Lidar (DIAL), electron capture detector-gas chromatograph, grab samples/gas chromatograph, inertial navigation system, photoelectric cell, resistance temperature detector, two photon/laser induced fluorescence, and a tunable diode laser.
The ABLE 3A results indicate that human activities may have already enhanced total "reactive" nitrogen inputs to the Arctic and Sub-Arctic regions to the extent that the lifetime of ozone against photochemical loss may have already doubled.
This data set consists of the aircraft measurements of chemical species. There are also ABLE 3A data sets for a ground site (GTE_A3A_TOWER), for isentropic back trajectories generated for the program time frame (GTE_A3A_MET_TRAJ) and a data set for airborne flux measurements of trace species (GTE_A3A_ELEC_FLUX). These data sets are also available from the Langley DAAC.