92nd American Meteorological Society Annual Meeting (January 22-26, 2012)

Monday, 23 January 2012: 11:15 AM
MISR Perspective on Spatial and Temporal Variability in East Asian Deserts: Relation to Climate Factors
Room 257 (New Orleans Convention Center )
Olga V. Kalashnikova, JPL, Pasadena, CA; and J. N. Lee, D. I. N. Sokolik, M. J. Garay, O. Torres, and M. de la Torre Juárez

Despite its well-recognized importance, the impact of mineral aerosol (dust) on the environment and its relation to climate factors remains difficult to quantify. The 11+ years of data from Multi-angle Imaging SpectroRadiometer (MISR) instrument on the polar-orbiting Terra satellite provide a unique, independent source of data for studying dust emissions. MISR's multiple view angles allow the retrieval of aerosol properties over bright surfaces, and such retrievals have been shown to be sensitive to the non-sphericity of dust aerosols over both land and water. We provide a satellite prospective on Asian dust source climatology and relation to climate factors using aerosol data from MISR supplemented by available records from Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue aerosol products, and Ozone Monitoring Instrument (OMI) aerosol products. We evaluate the realism of the satellite climatological characterization of Asian dust against AERONET and meteorological data, and will discuss observed differences between the space-based sensors' aerosol products. Utilizing the strengths and accounting for the biases of the current satellite products over the desert areas, we investigate multi-year spatial and temporal behavior of Asian dust in terms of aerosol optical depth (AOD) and aerosol index (AI). In particular, we examine the multi-annual mean pattern, seasonal cycle, inter-annual variability, and trends of Asian dust emissions. Combined satellite observations do not show statistically significant trends over the natural deserts; natural aerosol loadings seem to be predominantly affected by large-scale climatological factors. We analyze the combined effects of the Arctic Oscillation (AO) and El Niño/Southern Oscillation (ENSO) on inter-annual variability of dust occurrence in Asian deserts. We find a strong correlation between satellite-observed aerosol loadings and the Nino 3.4 index during the boreal spring months. The results of composite analysis of negative and positive phases of AO show clearly that negative AO enhances dust storm activities as suggested by previous modeling studies. The reasons for the correlations are analyzed in terms of temperature, precipitation, and wind fields.

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