Background

Initiated in 2007, the 7-SEAS project (cf. whitepaper in http://7-seas.gsfc.nasa.gov/; http://www.nrlmry.navy.mil/aerosol_web/7seas/7seas.html; Reid et al., 2013; Lin et al., 2013) seeks to perform interdisciplinary research in the field of aerosol-meteorology and climate interaction from Java through the Malay Peninsula, and Southeast Asia to Taiwan. The primary scientific goal is to investigate the impact of biomass burning on clouds, atmospheric radiation, the hydrological cycle, and ultimately regional weather and climate. Countries with participating scientists and programmatic elements include Indonesia, Malaysia, Philippines, Singapore, Thailand, Taiwan, Vietnam, and the USA (e.g. NASA; Naval Research Laboratory, NRL; Office of Naval Research, ONR; Office of Naval Research-Global, ONRG; and many universities). The 7-SEAS is a grass-roots style program which promotes collaboration, builds capacity, and shares information throughout the region on science, field data, and observing systems. The study region, which ranges from the tropics to subtropics, has significant gradients in air pollution varying from near pristine to heavily-polluted. Thus, SEA’s geography provides a unique natural laboratory for atmospheric measurements.

The Virtual Biomass Burning Experiment (VBBE) in August 2007 (cf. http://www.nrlmry.navy.mil/aerosol/7-SEAS/) was executed to collect and archive a dataset over SEA enabling 7-SEAS participating members to become familiar with experiment protocols and products. Measurements in the southern domain commenced in boreal summer-fall 2009 with the development of the National University of Singapore supersite. During the spring seasons of 2010-2012, a series of pilot IOPs in the northern regions of the 7-SEAS domain were successfully conducted, which included the Dongsha Experiment in 2010 (cf. http://aerosol.atm.ncu.edu.tw/DongSha/ and Wang et al., 2011; Tsay et al., 2013; Lin et al., 2013), and the Son La Campaign I and II during 2011 and 2012 boreal spring seasons, respectively. Furthermore, a joint international effort, named as the 7-SEAS/BASELInE (Biomass-burning Aerosols & Stratocumulus Environment: Lifecycles and Interactions Experiment), has been conducted during February-May 2013 in the same region. The 7-SEAS/BASELInE would provide a basis for a deeper improvement of the understanding of the lifecycles of regional biomass-burning aerosols, and their interactions with stratocumulus clouds during the Asian pre-monsoon season. The results from these planned studies, in turn, would shed new light on the range of potential effects on water cycle due to regional anthropogenic activities.

  • Wang et al. (2011) First detailed observations of long-range transported dust over the northern South China Sea.
  • Lin et al. (2013) An overview of regional experiments on biomass burning aerosols and related pollutants in Southeast Asia: From BASE-ASIA and the Dongsha Experiment to 7-SEAS
  • Reid et al. (2013) Observing and understanding the Southeast Asian aerosol system by remote sensing: An initial review and analysis for the Seven Southeast Asian Studies (7SEAS) program

Main themes 7-SEAS investigates

  • Clouds and precipitation
  • Radiative transfer
  • Anthropogenic and biomass-burning emissions and evolution
  • Natural background atmospheric chemistry
  • Tropical-subtropical meteorology
  • Regional nowcasting, forecasting, and inter-annual/climate outlooks
  • Calibration/validation