Modelling noise from wind, rain and distant shipping in scenarios of varying complexity

Passive sonars attempt to detect sound radiated by vessels of interest. This detection takes place against a background of noise, with important sources of noise including distant shipping, rain falling on the sea surface and breaking waves and bursting bubbles associated with sea-surface waves. The estimation of these noises is therefore an...

Characterization of precipitation through copulas and expert judgement for risk assessment of infrastructure

In this paper two methodologies are investigated that contribute to better assessment of risks related to extreme rainfall events. Firstly, one-parameter bivariate copulas are used to analyze rain gauge data in the Netherlands. Out of three models considered, the Gumbel copula, which indicates upper tail dependence, represents the data most...

Improving the modeling of road dust levels for Barcelona at urban scale and street level

Road dust emission is an emerging issue in air quality due to the lack of remediation measures in contrast to vehicle exhaust emissions. The evidence of receptor modeling studies allows for quantifying impact on a few receptors, but the high cost of PM chemical speciation data and the questionable representativeness of single monitoring sites,...

The influence of adverse weather conditions on probability of congestion on dutch motorways

Weather conditions are widely acknowledged to contribute to the occurrence of congestion on motorway traffic by influencing both traffic supply and traffic demand. To the best of our knowledge, this is the first paper that explicitly integrates supply and demand effects in predicting the influence of adverse weather conditions on the probability...

Implementation and evaluation of pH-dependent cloud chemistry and wetdeposition in the chemical transport model REM-Calgrid

The Chemistry Transport Model REM-Calgrid (RCG) has been improved by implementing an enhanced description of aqueous-phase chemistry and wet deposition processes including droplet pH. A sensitivity study on cloud and rain droplet pH has been performed to investigate its impact on model sulphate production and gas wet scavenging. Air...

Update on the Status of the On-Going Range Dependent Low Frequency Active Sonar Model Benchmarking Effort: From Cambridge to Kos [abstract]

In April 2010, a symposium in Memory of David Weston was held at Clare College in Cambridge (UK). International researchers from academia and research laboratories met to discuss two sets of test problems for sonar performance models, one aimed at understanding mammal echolocation sonar („Problem AI‟), and the other at benchmarking low frequency...

An Analytical Solution for Signal Background and Signal to background Ratio for a Low Frequency Active Sonar in a Pekerisch Waveguide Satisfying Lambert's Rule

Previously published equations for the time dependence of the echo and reverberation in a Pekeris waveguide are combined with an expression derived for surface-generated noise. These closed form solutions are applied to the calculation of signal to reverberation ratio and signal to total background ratio for three CW pulses with centre...

Non-exhaust emissions of PM and the efficiency of emission reduction by road sweeping and washing in the Netherlands

From research on PM_2.5 and PM₁₀ in 2007/2008 in the Netherlands, it was concluded that the coarse fraction (PM_2.5-10) attributed 60% and 50% respectively, to the urban-regional and street-urban increments of PM₁₀. Contrary to Scandinavian and Mediterranean countries which exhibit significant seasonal...

Development of an algorithm for using weather-dependent dynamic speed limits to enhance safety

This paper describes an ongoing research project in the Netherlands for lowering the speed limit, depending on the weather condition (in particular rain) to enhance traffic safety. The research in this project consists of three main parts. In the first part, research has been conducted on the strategy of speed limits to be displayed: in what...

Comparison of selection methods to deduce natural background levels for groundwater units

Establishment of natural background levels (NBL) for groundwater is commonly performed to serve as reference when assessing the contamination status of groundwater units. We compare various selection methods to establish NBLs using groundwater quality data forfour hydrogeologically different areas in the highly populated and developed...

Xeno-estrogenic compounds in precipitation

The exposure to some chemicals can lead to hormone disrupting effects. Presently, much attention is focused on so-called xeno-estrogens, synthetic compounds that interact with hormone receptors causing a number of reactions that eventually lead to effects related to reproduction and development. The current study was initiated to investigate the...

Geochemistry and flooding as determining factors of plant species composition in Dutch winter-flooded riverine grasslands

Dutch water policy aims for more frequent, controlled flooding of river valley floodplains to avoid unwanted flooding elsewhere; in anticipation of increased flooding risks resulting from climate changes. Controlled flooding usually takes place in winter in parts of the valleys which had not been subject to flooding in the last decades. It may...

Groundwater chemistry of Al under Dutch sandy soils: Effects of land use and depth

Aluminium has received great attention in the second half of the 20th century, mainly in the context of the acid rain problem mostly in forest soils. In this research the effect of land use and depth of the groundwater on Al, pH and DOC concentration in groundwater under Dutch sandy soils has been studied. Both pH and DOC concentration play a...

Track decay rate measurements using the PBA technque

Track decay rates are an important quanty relevant for raiway rolng noise. The vertical and ateral track decay rates are used to characterise he dynamc behaviour of the rack, both as an nput to calculations and for track characterisation given n EU regulations (TSIs). TNO has developed ethods and software capable of deriving he decay rates,...

Two-way multi-band optical/IR transmisson measurement in the Persian Gulf-coastal region

The atmospheric conditions in the Persian Gulf region are significantly different from other places in the world. The particle size distribution may vary daily and during the day. The aerosols can contribute to the amount of rainfall over land, important for the nations around the Gulf. In 2004 NASA/GSFC and NRL (Naval Research Laboratory)...

The aerosol project: Introduction and some background information

This paper provides an introduction to a series of publications in this issue of Atmospheric Environment, all summarising the results of the 'Aerosol project'. The aim of this project was (i) to quantify the contribution of acidifying aerosols to the total acid input in nature areas, (ii) to determine the contribution of aerosol deposition and...