The paper presents in detail a code developed to solve the vector equation of radiative transfer. It is based on the successive orders of scattering and on the expansion into Fourier series of the ...azimuth; it includes the polarizing effects of aerosol scattering and of reflectance by water or terrestrial surfaces. The code is available from the authors upon request, and this detailed description aims at helping potential users to adapt the code to their own problem. Some examples of applications are given.
The launch of ADEOS in August 1996 with POLDER, TOMS, and OCTS instruments on board and the future launch of EOS‐AM 1 in mid‐1998 with MODIS and MISR instruments on board start a new era in remote ...sensing of aerosol as part of a new remote sensing of the whole Earth system (see a list of the acronyms in the Notation section of the paper). These platforms will be followed by other international platforms with unique aerosol sensing capability, some still in this century (e.g., ENVISAT in 1999). These international spaceborne multispectral, multiangular, and polarization measurements, combined for the first time with international automatic, routine monitoring of aerosol from the ground, are expected to form a quantum leap in our ability to observe the highly variable global aerosol. This new capability is contrasted with present single‐channel techniques for AVHRR, Meteosat, and GOES that although poorly calibrated and poorly characterized already generated important aerosol global maps and regional transport assessments. The new data will improve significantly atmospheric corrections for the aerosol effect on remote sensing of the oceans and be used to generate first real‐time atmospheric corrections over the land. This special issue summarizes the science behind this change in remote sensing, and the sensitivity studies and applications of the new algorithms to data from present satellite and aircraft instruments. Background information and a summary of a critical discussion that took place in a workshop devoted to this topic is given in this introductory paper. In the discussion it was concluded that the anticipated remote sensing of aerosol simultaneously from several space platforms with different observation strategies, together with continuous validations around the world, is expected to be of significant importance to test remote sensing approaches to characterize the complex and highly variable aerosol field. So far, we have only partial understanding of the information content and accuracy of the radiative transfer inversion of aerosol information from the satellite data, due to lack of sufficient theoretical analysis and applications to proper field data. This limitation will make the anticipated new data even more interesting and challenging. A main concern is the present inadequate ability to sense aerosol absorption, from space or from the ground. Absorption is a critical parameter for climate studies and atmospheric corrections. Over oceans, main concerns are the effects of white caps and dust on the correction scheme. Future improvement in aerosol retrieval and atmospheric corrections will require better climatology of the aerosol properties and understanding of the effects of mixed composition and shape of the particles. The main ingredient missing in the planned remote sensing of aerosol are spaceborne and ground‐based lidar observations of the aerosol profiles.
Summary
Background
While overweight and obese children are more likely to have overweight or obese parents, less is known about the effect of parental weight status on children's success in weight ...management programmes.
Objectives
This study was a secondary data analysis of a randomized controlled trial and investigated the impact of having zero, one or two obese parents on children's success in a school‐based weight management programme.
Methods
Sixty‐one Mexican–American children participated in a 24‐week school‐based weight management intervention which took place in 2005–2006. Children's heights and weights were measured at baseline, 3, 6 and 12 months. Parental weight status was assessed at baseline. Repeated measures anova and ancova were conducted to compare changes in children's weight within and between groups, respectively.
Results
Within‐group comparisons revealed that the intervention led to significant decreases in standardized body mass index (zBMI) for children with zero (F = 23.16, P < .001) or one obese (F = 4.99, P < .05) parent. Between‐group comparisons indicated that children with zero and one obese parents demonstrated greater decreases in zBMI compared to children with two obese parents at every time point.
Conclusions
The school‐based weight management programme appears to be most efficacious for children with one or no obese parents compared to children with two obese parents. These results demonstrate the need to consider parental weight status when engaging in childhood weight management efforts.
The title compounds were synthesized by applying the 1,3-dipolar cycloaddition reaction of aldehyde-based poly(benzyl ether) dendrimers and sarcosine (N-methylglycine) to 60fullerene (C60). The ...dendritic building blocks used to functionalize C60 displayed cubic and hexagonal columnar phases. The fullerene derivatives showed rectangular columnar phases of c2mm symmetry.
Spectral UV global irradiance has been measured regularly during the year 2000, in the French Alps, using two UV spectroradiometers. The total ozone column amount is retrieved from the ratio of ...irradiances around 305 and 340 nm, using look up tables based on modeling data. During cloudless days, ozone values from direct sun observations agree to within 5 DU. These ground based values compare reasonably well (to within about 4%, or 12 DU) with TOMS ozone data; this is consistent with the uncertainty of both methods which is estimated to 5 DU for TOMS, and 5–7 DU for clear sky ground based measurements. Generally the ground based ozone values seem to be slightly higher than the TOMS ozone values. For a few cases, the difference between TOMS and ground based values, can reach 10 to 15%. Different possible explanations of the discrepancies are considered.
The International Photolysis Frequency Measurement and Model Intercomparison (IPMMI) took place in Boulder, Colorado, from 15 to 19 June 1998, aiming to investigate the level of accuracy of ...photolysis frequency and spectral downwelling actinic flux measurements and to explore the ability of radiative transfer models to reproduce the measurements. During this period, 2 days were selected to compare model calculations with measurements, one cloud‐free and one cloudy. A series of ancillary measurements were also performed and provided parameters required as input to the models. Both measurements and modeling were blind, in the sense that no exchanges of data or calculations were allowed among the participants, and the results were objectively analyzed and compared by two independent referees. The objective of this paper is, first, to present the results of comparisons made between measured and modeled downwelling actinic flux and irradiance spectra and, second, to investigate the reasons for which some of the models or measurements deviate from the others. For clear skies the relative agreement between the 16 models depends strongly on solar zenith angle (SZA) and wavelength as well as on the input parameters used, like the extraterrestrial (ET) solar flux and the absorption cross sections. The majority of the models (11) agreed to within about ±6% for solar zenith angles smaller than ∼60°. The agreement among the measured spectra depends on the optical characteristics of the instruments (e.g., slit function, stray light rejection, and sensitivity). After transforming the measurements to a common spectral resolution, two of the three participating spectroradiometers agree to within ∼10% for wavelengths longer than 310 nm and at all solar zenith angles, while their differences increase when moving to shorter wavelengths. Most models agree well with the measurements (both downwelling actinic flux and global irradiance), especially at local noon, where the agreement is within a few percent. A few models exhibit significant deviations with respect either to wavelength or to solar zenith angle. Models that use the Atmospheric Laboratory for Applications and Science 3 (ATLAS‐3) solar flux agree better with the measured spectra, suggesting that ATLAS‐3 is probably more appropriate for radiative transfer modeling in the ultraviolet.
The validity of a radiative transfer model can be checked either by comparing its results with measurements or with solutions for artificial cases. Unfortunately, neither type of comparison can ...guarantee that the spectral UV surface irradiance is accurately calculated for real atmospheric cases. There is a need therefore for benchmarks, i.e., standard results that can be used as a validation tool for UV radiation models. In this paper we give such benchmarks for six cloud‐free situations. The chosen cases are characterized by different values of solar zenith angle, ozone column, aerosol loading, and surface albedo. Observations are also available for these cases to allow a further comparison between model results and measurements. An intercomparison of 12 numerical models is used to construct the benchmarks. Each model is supplied with identical input data, and a distinction is made between models that assume a planeparallel geometry and those that use a pseudospherical approximation. Differences remain between the model results, because of different treatments of the input data set. Calculations of direct and global transmission and direct and global irradiance are within 3% for wavelengths longer than 320 nm. For the low‐Sun cases the calculations are within 10% for wavelengths longer than 300 nm. On the basis of these calculations, six benchmark UV spectra (295–400 nm) are established with a standard deviation of 2%. Relative standard deviations are higher for the lowest absolute intensities at low Sun (5% at 300 nm). The variation between models is typically less than the variation seen between model and measurement. Differences between the benchmarks and the observed spectra are mainly due to the uncertainty in the input parameters. In four of the six cases the benchmarks agree with the observed spectra within 13% over the whole UV spectral region.
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