Introduction to special section: Outstanding problems in quantifying the radiative impacts of mineral dust

This paper provides an introduction to the special section of the Journal o f Geophysical Research on mineral dust. We briefly review the current exper imental and theoretical approaches used to quantify the dust radiative impa cts, highlight the outstanding issues, and discuss possible strategies to o vercome the emerging problems. We also introduce the contributing papers of this special section. Despite the recent notable advances in dust studies, we demonstrate that the radiative effects of dust remain poorly quantified due to both limited data and incomplete understanding of relative physical and chemical processes. The foremost needs are (1) to quantify the spatial and temporal variations of dust burden in the atmosphere and develop a pre dictive capability for the size- and composition-resolved dust particle dis tribution; (2) to develop a quantitative description of the processes that control the spatial and temporal variabilities of dust physical and chemica l properties and radiative effects; (3) to develop new instrumentation (esp ecially to measure the dust particle size distribution in a wide range from about 0.01 mum to 100 tm, scattering phase function and light absorption b y dust particles); and (4) to develop new techniques for interpreting and m erging the diverse information from satellite remote sensing, in situ and g round-based measurements, laboratory studies, and model simulations. Becaus e dust distribution and effects are heterogeneous, both spatially and tempo rally, a promising strategy to advance our knowledge is to perform comprehe nsive studies at the targeted regions affected by mineral dust of both natu ral and anthropogenic origin.