Search results for "HM"

Mass levels, crustal component and trace elements in PM10 in Palermo, Italy.

2007

Abstract Results concerning the levels and elemental compositions of daily PM 10 samples collected at four air quality monitoring sites in Palermo (Italy) are presented. The highest mean value of PM 10 concentrations (46 μg m −3 , with a peak value of 158 μg m −3 ) was recorded at the Di Blasi urban station, and the lowest at Boccadifalco station (25 μg m −3 ), considered as a sub-urban background station. Seventeen elements (Al, As, Ba, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Sb, Sr, U, V, Zn) were measured by ICP-MS. Al and Fe showed the highest concentrations, indicating the significant contribution of soil and resuspended mineral particles to atmospheric PM 10 . Ba, Cr, Cu, Mn, Mo, Ni, Pb, …

Investigation of the mixing layer height derived from ceilometer measurements in the Kathmandu Valley and implications for local air quality

2017

Abstract. In this study 1 year of ceilometer measurements taken in the Kathmandu Valley, Nepal, in the framework of the SusKat project (A Sustainable Atmosphere for the Kathmandu Valley) were analysed to investigate the diurnal variation of the mixing layer height (MLH) and its dependency on the meteorological conditions. In addition, the impact of the MLH on the temporal variation and the magnitude of the measured black carbon concentrations are analysed for each season. Based on the assumption that black carbon aerosols are vertically well mixed within the mixing layer and the finding that the mixing layer varies only little during night time and morning hours, black carbon emission fluxe…

AATSR land surface temperature product algorithm verification over a WATERMED site

2007

Abstract A new operational Land Surface Temperature (LST) product generated from data acquired by the Advanced Along-Track Scanning Radiometer (AATSR) provides the opportunity to measure LST on a global scale with a spatial resolution of 1 km 2 . The target accuracy of the product, which utilises nadir data from the AATSR thermal channels at 11 and 12 μm, is 2.5 K for daytime retrievals and 1.0 K at night. We present the results of an experiment where the performance of the algorithm has been assessed for one daytime and one night time overpass occurring over the WATERMED field site near Marrakech, Morocco, on 05 March 2003. Top of atmosphere (TOA) brightness temperatures (BTs) are simulate…

MEASUREMENT AND ANALYSIS OF ULTRAVIOLET SOLAR IRRADIATION IN VALENCIA, SPAIN

1996

Experimental data concerning the integrated total ultraviolet radiation (290–385 nm band) on a horizontal surface measured at Valencia (Spain) during the period March 1991 to December 1994 have been analysed. A study of the most representative statistical indexes: arithmetic mean (M), median (Md), standard deviation (SD), maximum (Mx), minimum (Mn), first (Q1) and third (Q3) quartiles, percentiles 5 (P5) and 95 (P95), interquartile range (Q3 –Q1) and coefficient of quartile variation (V), of the UV radiation for this period has been carried out. The study has focused on both the hourly and the daily values of irradiance. The UV irradiance measured shows quite stable values within the period…

Surface temperature retrieval from Along Track Scanning Radiometer 2 data: Algorithms and validation

2004

[1] A study has been carried out using MODTRAN 3.5 simulations of the Along Track Scanning Radiometer 2 (ATSR-2) data at 3.7, 11, and 12 μm wavelengths to give a range of algorithms for estimating surface. Making use of the dual-angle feature of the ATSR-2, algorithms based on dual-angle, split-window, and mixed structure have been considered. The coefficients of the algorithms are derived by regression analysis using the MATLAB code. The evaluation of the sensitivity of each algorithm shows that in general, dual-angle algorithms provide smaller errors in the estimation of surface temperature than the split-window algorithms and that the algorithms with water vapor dependence give an improv…

2017

Abstract. We present a Monte Carlo genetic algorithm (MCGA) for efficient, automated, and unbiased global optimization of model input parameters by simultaneous fitting to multiple experimental data sets. The algorithm was developed to address the inverse modelling problems associated with fitting large sets of model input parameters encountered in state-of-the-art kinetic models for heterogeneous and multiphase atmospheric chemistry. The MCGA approach utilizes a sequence of optimization methods to find and characterize the solution of an optimization problem. It addresses an issue inherent to complex models whose extensive input parameter sets may not be uniquely determined from limited in…

Assessment of maize nitrogen uptake from PRISMA hyperspectral data through hybrid modelling

2022

Revision of the Single-Channel Algorithm for Land Surface Temperature Retrieval From Landsat Thermal-Infrared Data

2009

This paper presents a revision, an update, and an extension of the generalized single-channel (SC) algorithm developed by Jimenez-Munoz and Sobrino (2003), which was particularized to the thermal-infrared (TIR) channel (band 6) located in the Landsat-5 Thematic Mapper (TM) sensor. The SC algorithm relies on the concept of atmospheric functions (AFs) which are dependent on atmospheric transmissivity and upwelling and downwelling atmospheric radiances. These AFs are fitted versus the atmospheric water vapor content for operational purposes. In this paper, we present updated fits using MODTRAN 4 radiative transfer code, and we also extend the application of the SC algorithm to the TIR channel …

Beating Darwin-Bragg losses in lab-based ultrafast x-ray experiments

2017

The use of low temperature thermal detectors for avoiding Darwin-Bragg losses in lab-based ultrafast experiments has begun. An outline of the background of this new development is offered, showing the relevant history and initiative taken by this work. (C) 2017 Author(s). Funding Agencies|Knut and Alice Wallenberg Foundation; ERC [226136]; Finnish Funding Agency for Technology and Innovation TEKES; Academy of Finland [260880]; NIST Innovations in Measurement Science program; DOE Office of Basic Energy Sciences

Efficient distributed average consensus in wireless sensor networks

2020

International audience; Computing the distributed average consensus in Wireless Sensor Networks (WSNs) is investigated in this article. This problem, which is both natural and important, plays a significant role in various application fields such as mobile agents and fleet vehicle coordination, network synchronization, distributed voting and decision, load balancing of divisible loads in distributed computing network systems, and so on. By and large, the average consensus' objective is to have all nodes in the network converged to the average value of the initial nodes' measurements based only on local nodes' information states. In this paper, we introduce a fully distributed algorithm to a…