In this paper, we discuss the measurements of spectral surface reflectance (rholambdas) in the wavelength range 350-2500 nm measured using a spectroradiometer onboard a low-flying aircraft over Bangalore (12.95degN, 77.65deg E), an urban site in southern India. The large discrepancies in the retrieval of aerosol properties over land by the Moderate-Resolution Imaging Spectroradiometer (MODIS), which could be attributed to the inaccurate estimation of surface reflectance at many sites in India and elsewhere, provided motivation for this paper. The aim of this paper was to verify the surface reflectance relationships assumed by the MODIS aerosol algorithm for the estimation of surface reflectance in the visible channels (470 and 660 nm) from the surface reflectance at 2100 nm for aerosol retrieval over land. The variety of surfaces observed in this paper includes green and dry vegetations, bare land, and urban surfaces. The measured reflectance data were first corrected for the radiative effects of atmosphere lying between the ground and aircraft using the Second Simulation of Satellite Signal in the Solar Spectrum (6S) radiative transfer code. The corrected surface reflectance in the MODIS's blue (rho470s), red (rho660s), and shortwave-infrared (SWIR) channel (rho2100s) was linearly correlated. We found that the slope of reflectance relationship between 660 and 2100 nm derived from the forward scattering data was 0.53 with an intercept of 0.07, whereas the slope for the relationship between the reflectance at 470 and 660 nm was 0.85. These values are much higher than the slope ( ~0.49) for either wavelengths assumed by the MODIS aerosol algorithm over this region. The reflectance relationship for the backward scattering data has a slope of 0.39, with an intercept of 0.08 for 660 nm, and 0.65, with an intercept of 0.08 for 470 nm. The large values of the intercept (which is very small in the MODIS reflectance relationships) result in larger values of absolute surface reflectance in the visible channels. The discrepancy between the measured and assumed surface reflectances could lead to error in the aerosol retrieval. The reflectance ratio (rho660s/rho2100s) showed a clear dependence on theNDVISWIRwhere the ratio increased from 0.5 to 1 with an increase inNDVISWIRfrom 0 to 0.5. The high correlation between the reflectance at SWIR wavelengths (2100, 1640, and 1240 nm) indicated an opportunity to derive the surface reflectance and, possibly, aerosol properties at these wavelengths. We need more experiments to characterize the surface reflectance and associated inhomogeneity of land surfaces, which play a critical role in the remote sensing of aerosols over land.

There is a large uncertainty in the estimation of dust radiative forcing due to the lack of adequate data about complex spatial and temporal pattern of the radiative properties of dust. Here, we examine the temporal and spatial variability of dust absorption in the thermal infrared over the Afro-Asian regions using satellite data. Large dust absorption (nearly double compared to that of pure dust) was observed in regions with large anthropogenic influence, possibly due to deposition of black carbon on dust particles. While most of the recent estimates of global mean dust radiative forcing predicted net cooling, our studies indicate that there could be large heating due to dust over vast Afro-Asian regions. It appears that large dust heating is due to its interaction with anthropogenic black carbon

OdeView is the graphical front end for Ode, an object-oriented database system and environment. Ode's data model supports data encapsulation, type inheritance, and complex objects. OdeView provides facilities for examining the database schema (i.e., the object type or class hierarchy), examining class definitions, browsing objects, following chains of references starting from an object, synchronized browsing, displaying selected portions of objects (projection), and retrieving objects with specific characteristics (selection).

OdeView is the graphical front end for Ode, an object-oriented database system and environment. It is intended for users who do not want to write programs in Ode's database programming language O++ to interact with Ode but instead want to use a friendlier interface to Ode. OdeView is based on the graphical direct manipulation paradigm that involves selection of items from pop-up menus and icons that can be clicked on and dragged. OdeView provides facilities for examining the database schema examining class definitions, browsing objects, following chains of references, displaying selected portions of objects or selecting a subset of the ways in which an object can be displayed (projection), and retrieving specific objects (selection).