Proposal Plan

PI Name:	MH Bergin
Co-Investigators:	WL Chameides, GR Cass
Proposal Title:	Measurement of aerosol chemical, physical, and radiative properties related to climate forcing in the Yangtze delta region of China
Proposal Synopsis:	As part of ACE-ASIA we propose to measure a variety of aerosol chemical, physical, and radiative properties at a location in the Yangtze delta region of China. We will take advantage of the facilities and experience we have at Georgia Tech in aerosol measurements as a result of our lead role in EPA-sponsored projects such as the Atlanta SuperSite Experiment and SCISSAP, and in conducting field measurements in China as a result of activities related to CHINA-MAP. We will conduct a basic set of measurements over a 2-year period, with a more sophisticated suite of measurements taking place during the ACE-ASIA intensive sampling period. The measurements will focus on the estimation of the magnitude of direct shortwave radiative forcing by aerosols in this region. In order to do this we will make continuous measurements of aerosol light scattering, and absorption coefficients at the surface as well as routine measurements of aerosol optical depth. We will use these measurements, along with measurements of size-resolved chemical composition which will be used to estimate the aerosol upscatter fraction, to estimate the impact of aerosols on the shortwave radiation balance at the surface and top of the atmosphere using a multistream radiative transfer model (MODTRAN). We will also measure the total downwelling shortwave irradiance and downwelling photosynthetically active radiation (PAR), and will compare model estimates of surface irradiances with measurements. In addition, we will measure aerosol mass, inorganic ion, organic carbon, elemental carbon, and trace metal concentrations. In particular, we will examine the relative contributions of organic carbon, sulfate, and wind blown dust to the light extinction budget. Overall, the study will result in a better understanding of the temporal variability of aerosol properties in this region, as well as the relationship between anthropogenic aerosols and direct shortwave radiative forcing. The data will be integrated with other aerosol measurements being made during ACE-ASIA to better understand the spatial variability of aerosol properties in Asia. In addition, the data will prove useful in future modeling efforts focusing on the emission, transport, and transformation of Asian aerosol.