The land below the wind: Doppler LiDAR observations from the tropical rain forest of Sabah, Borneo, Malaysia

Abstract

Tropical forests account for over half of the world’s forests (1.8 billion hectares) and act as a massive source of matter and energy for the lower atmosphere. The humid tropics exhibit some of the most dynamic yet poorly understood biogeochemical behaviour on Earth. This behaviour is driven by solar radia-tion and mediated by its transformation into latent and sensible heat, with concomitant uptake of carbon by photosynthesis and the resultant emission of reactive and unreactive trace gases, water vapour and energy into the atmosphere. A further important conse-quence of the large solar radiation flux is the vigorous convective uplift that occurs, which results in the rapid movement of chemical species emitted within the forest canopy into the free troposphere. Many aerosols in the upper troposphere contain oxygenated organic material originating from the bound-ary layer, and the influence of these on cloud formation remains to be clarified (Lehieveld