【LABS synopsis】Background Explanation

Rapid expansion of urbanization and industrialization has been continuing in East Asia over the last few decades. The growth not only happened in economy, but also brought tremendous amount of air pollutants to this region and spread to the Northern Hemisphere. Meanwhile, remarkable land use change in East Asia largely contributes the sources and sinks of air pollutants. It is therefore vital to characterize the behaviors of the atmospheric constituents and to assess the mechanisms and impacts on regional climate.

Taiwan is situated in a unique position in East Asia in terms of observing pollution outflows from Southeast Asia and the Asian continent. For instance, Chinese haze can be transported to northern Taiwan within the boundary layer along with frontal passages driven by winter monsoon. In the free troposphere, the concentrations of air constituents, e.g. CO, O3, PM, and atmospheric mercury, can be significantly elevated in associated with the polluted air masses induced by the biomass burning activities in Southeast Asia every spring.

Although Taiwan EPA has established a rather high-density ground-level network of air quality stations (79 stations island-wide) over the last two decades, most of them only represent local characteristics. Thus, the Lulin Atmospheric Background Station (LABS; 23.47°N, 120.87°E; 2862 m amsl) has been established through the collaborations of Taiwan EPA, MOST and NCU. The LABS is an ideal site located at the peak of Mt. Front Lulin in Yu-Shan National Park in central Taiwan to monitor the changes in baseline concentrations of various key pollutants released from the Asian continent into the Pacific. The LABS is frequently within the free troposphere in the East Asia region where no other high elevation baseline station is available. The LABS was opened on 13th April, 2006. The design and operation of the LABS follow the WMO/GAW and NOAA/GMD guidelines/protocols.