Comparison of modelled atmospheric aerosol content and its influence on high-energy laser propagation

Aerosol content of the atmosphere is an important factor in the propagation of high-energy laser (HEL) beams. Aerosol absorption leads to the thermal blooming effect, where the laser beam heats the air and thereby creates a diverging lens. We have used three methods to estimate the aerosol absorption coefficient: (1) a Mie calculation on...

Dip coating of air purifier ceramic honeycombs with photocatalytic TiO2 nanoparticles: A case study for occupational exposure

Nanoscale TiO2 (nTiO2) is manufactured in high volumes and is of potential concern in occupational health. Here, we measured workers exposure levels while ceramic honeycombs were dip coated with liquid photoactive nanoparticle suspension and dried with an air blade. The measured nTiO2 concentration levels were used to assess process specific...

The Advanced Navy Aerosol Model (ANAM): Validation of small-particle modes

The image quality of electro-optical sensors in the (lower-altitude marine) atmosphere is limited by aerosols, which cause contrast reduction due to transmission losses and impact on the thermal signature of objects by scattering solar radiation. The Advanced Navy Aerosol Model (ANAM) aims at providing a quantitative estimate of the aerosol...

The Ångström coefficient as an indicator of non-marine particles in ANAM (Advanced Navy Aerosol Model)

The Advanced Navy Aerosol model (ANAM), being a modified version of the Navy Aerosol Model (NAM), is a wellknown engineering tool providing a quick and reasonable estimate of the aerosol extinction in the marine near-surface environment on the basis of simple meteorological input data. The original NAM consists of 3 lognormal distributions,...

AMARSI: Aerosol modeling and retrieval from multi-spectral imagers

The AMARSI project aims at the development and validation of aerosol retrieval algorithms over ocean. One algorithm will be developed for application with data from the Multi Spectral Imager (MSI) on EarthCARE. A second algorithm will be developed using the combined information from AATSR and MERIS, for application to similar instruments on...

Improvements in the Advanced Navy Aerosol Model (ANAM)

The Navy Aerosol Model (NAM) is widely used as an engineering tool to provide a quick estimate of the aerosol extinction in the marine environment. Since its introduction, several shortcomings of NAM have been identified that are being addressed by the development of the Advanced Navy Aerosol Model (ANAM). At present, the Advanced Navy Aerosol...

ANAM vs. NAM: Is the difference significant?

The Navy Aerosol Model (NAM, available in MODTRAN) is widely used as a tool to assess the aerosol extinction in the marine atmospheric surface layer. NAM was built as a regression model in the 1980s to represent the aerosol extinction at deck height as a function of the meteorological conditions. The recently developed Advanced Navy Aerosol...

Near-surface aerosol transmission in the marine environment

An extensive data set of aerosol vertical concentration profiles (height range 0.5-15 meters, diameter range 10-75 micron), acquired with the Rotorod3 device at various geographical locations has been statistically analyzed. The analysis supplied a parameterization for the 4th (large particle) lognormal mode in the Advanced Navy Aerosol Model ...

Extension of the Navy aerosol model to coastal areas

The performance assessment of electro-optical (EO) systems with propagation prediction codes requires accurate atmospheric models. The model that is most frequently used for the prediction of aerosols and their effect on extinction in the marine atmosphere is the U.S. Navy aerosol model (NAM) (Gathman, 1983). The NAM was developed for open ocean...

Characterizing large aerosols in the lowest level of the marine atmosphere

This paper discusses techniques to describe the aerosol and the electro optical properties of the marine atmosphere from 15 meters down to the tops of the highest wave. Emphasis is placed on the experimental Rotorod technique to measure the concentrations of giant sea salt droplets. Data from these devices are parameterized using a lognormal...

Modeling aerosols and extinction in the marine atmospheric boundary layer

An analysis is presented of aerosol particle size distributions measured over the North Atlantic and extinction coefficients derived from these data. Two empirical models, an aerosol model and an extinction model, are formulated in terms of simple meteorological parameters (wind speed, relative humidity, air temperature and sea temperature). The...

NOVAM evaluation from aerosol and lidar measurements in a tropical marine environment

NOVAM, the Naval Oceanic Vertical Aerosol Model, has been developed to predict the nonuniform and nonlogarithmic extinction profiles that are often observed in the marine atmospheric boundary layer. The kernel of NOVAM is the Navy Aerosol Model (NAM) that calculates the aerosol size distribution at 10 m ASL from meteorological parameters. The...