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Arnoud Apituley

Bio: Arnoud Apituley is an academic researcher from Royal Netherlands Meteorological Institute. The author has contributed to research in topics: Lidar & Aerosol. The author has an hindex of 26, co-authored 106 publications receiving 3092 citations.


Papers
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Journal ArticleDOI
TL;DR: The European Aerosol Research Lidar Network (EARLINET) as mentioned in this paper was founded as a research project for establishing a quantitative, comprehensive, and statistically significant database for the horizontal, vertical, and tempo-ral distribution of aerosols on a continental scale.
Abstract: The European Aerosol Research Lidar Network, EARLINET, was founded in 2000 as a research project for establishing a quantitative, comprehensive, and statistically significant database for the horizontal, vertical, and tempo- ral distribution of aerosols on a continental scale. Since then EARLINET has continued to provide the most extensive col- lection of ground-based data for the aerosol vertical distribu- tion over Europe. This paper gives an overview of the network's main de- velopments since 2000 and introduces the dedicated EAR- LINET special issue, which reports on the present innova- tive and comprehensive technical solutions and scientific re- sults related to the use of advanced lidar remote sensing tech- niques for the study of aerosol properties as developed within the network in the last 13 years. Since 2000, EARLINET has developed greatly in terms of number of stations and spatial distribution: from 17 sta- tions in 10 countries in 2000 to 27 stations in 16 countries in 2013. EARLINET has developed greatly also in terms of technological advances with the spread of advanced multi- wavelength Raman lidar stations in Europe. The develop- ments for the quality assurance strategy, the optimization of instruments and data processing, and the dissemination of data have contributed to a significant improvement of the net- work towards a more sustainable observing system, with an increase in the observing capability and a reduction of oper- ational costs. Consequently, EARLINET data have already been ex- tensively used for many climatological studies, long-range transport events, Saharan dust outbreaks, plumes from vol- canic eruptions, and for model evaluation and satellite data validation and integration. Future plans are aimed at continuous measurements and near-real-time data delivery in close cooperation with other ground-based networks, such as in the ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) www.actris.net, and with the modeling and satellite commu- nity, linking the research community with the operational world, with the aim of establishing of the atmospheric part of the European component of the integrated global observ- ing system.

417 citations

Journal ArticleDOI
TL;DR: In this article, a new numerical module is proposed to compute the optical properties for 5 complex aerosol particles at low numerical cost so that it can be implemented in atmospheric models, which is validated for observations acquired during the EUCAARI campaign on the Cabauw tower during May 2008 and its computing cost is also estimated.
Abstract: Obtaining a good description of aerosol optical properties for a physically and chemically complex evolving aerosol is computationally very expensive at present. The goal of this work is to propose a new numerical module computing the optical properties for 5 complex aerosol particles at low numerical cost so that it can be implemented in atmospheric models. This method aims to compute the optical properties online as a function of a given complex refractive index deduced from the aerosol chemical composition and the size parameters corresponding to the particles. The construction of look-up tables from the imaginary and the real part of the com10 plex refractive index and size parameters will also be explained. This approach is validated for observations acquired during the EUCAARI campaign on the Cabauw tower during May 2008 and its computing cost is also estimated. These comparisons show that the module manages to reproduce the scattering and absorbing behaviour of the aerosol during most of the fifteen-day period of observation 15 with a very cheap computationally cost.

409 citations

Journal ArticleDOI
TL;DR: The Ozone Monitoring Instrument (OMI) on board the Aura satellite spanning a period of nearly 14 years has been used in a wide range of applications and research resulting in many new findings as mentioned in this paper.
Abstract: This overview paper highlights the successes of the Ozone Monitoring Instrument (OMI) on board the Aura satellite spanning a period of nearly 14 years. Data from OMI has been used in a wide range of applications and research resulting in many new findings. Due to its unprecedented spatial resolution, in combination with daily global coverage, OMI plays a unique role in measuring trace gases important for the ozone layer, air quality, and climate change. With the operational very fast delivery (VFD; direct readout) and near real-time (NRT) availability of the data, OMI also plays an important role in the development of operational services in the atmospheric chemistry domain.

266 citations

Journal ArticleDOI
TL;DR: In this paper, a major Saharan dust outbreak lasting from 26 to 31 May 2008 has been used as a case study for showing first results in terms of comparison with CALIPSO level 2 data.
Abstract: [1] A strategy for European Aerosol Research Lidar Network (EARLINET) correlative measurements for Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) has been developed. These EARLINET correlative measurements started in June 2006 and are still in progress. Up to now, more than 4500 correlative files are available in the EARLINET database. Independent extinction and backscatter measurements carried out at high-performance EARLINET stations have been used for a quantitative comparison with CALIPSO level 1 data. Results demonstrate the good performance of CALIPSO and the absence of evident biases in the CALIPSO raw signals. The agreement is also good for the distribution of the differences for the attenuated backscatter at 532 nm ((CALIPSO-EARLINET)/EARLINET (%)), calculated in the 1–10 km altitude range, with a mean relative difference of 4.6%, a standard deviation of 50%, and a median value of 0.6%. A major Saharan dust outbreak lasting from 26 to 31 May 2008 has been used as a case study for showing first results in terms of comparison with CALIPSO level 2 data. A statistical analysis of dust properties, in terms of intensive optical properties (lidar ratios, Angstrom exponents, and color ratios), has been performed for this observational period. We obtained typical lidar ratios of the dust event of 49 ± 10 sr and 56 ± 7 sr at 355 and 532 nm, respectively. The extinction-related and backscatter-related Angstrom exponents were on the order of 0.15–0.17, which corresponds to respective color ratios of 0.91–0.95. This dust event has been used to show the methodology used for the investigation of spatial and temporal representativeness of measurements with polar-orbiting satellites.

238 citations

Journal ArticleDOI
TL;DR: In this article, the authors used LIDAR observations to detect residual cloud contamination in the AERONET L1.5 data at Cabauw and showed a low correlation between the two properties.
Abstract: To acquire daily estimates of PM2.5 distributions based on satellite data one depends critically on an established relation between AOD and ground level PM2.5. In this study we aimed to experimentally establish the AOD-PM2.5 relationship for the Netherlands. For that purpose an experiment was set-up at the AERONET site Cabauw. The average PM 2.5 concentration during this ten month study was 18 μg/m 3, which confirms that the Netherlands are characterised by a high PM burden. A first inspection of the AERONET level 1.5 (L1.5) AOD and PM2.5 data at Cabauw showed a low correlation between the two properties. However, after screening for cloud contamination in the AERONET L1.5 data, the correlation improved substantially. When also constraining the dataset to data points acquired around noon, the correlation between AOD and PM2.5 amounted to R2=0.6 for situations with fair weather. This indicates that AOD data contain information about the temporal evolution of PM2.5. We had used LIDAR observations to detect residual cloud contamination in the AERONET L1.5 data. Comparison of our cloud-screed L1.5 with AERONET L2 data that became available near the end of the study showed favorable agreement. The final relation found for Cabauw is PM 2.5=124.5*AODĝ€"0.34 (with PM2.5 in μg/m3) and is valid for fair weather conditions. The relationship determined between MODIS AOD and ground level PM2.5 at Cabauw is very similar to that based on the much larger dataset from the sun photometer data, after correcting for a systematic overestimation of the MODIS data of 0.05. We applied the relationship to a MODIS composite map to assess the PM2.5 distribution over the Netherlands. Spatial dependent systematic errors in the MODIS AOD, probably related to variability in surface reflectance, hamper a meaningful analysis of the spatial distribution of PM2.5 using AOD data at the scale of the Netherlands.

225 citations


Cited by
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Journal ArticleDOI
03 Sep 2015-Nature
TL;DR: As a computational problem, global weather prediction is comparable to the simulation of the human brain and of the evolution of the early Universe, and it is performed every day at major operational centres across the world.
Abstract: Advances in numerical weather prediction represent a quiet revolution because they have resulted from a steady accumulation of scientific knowledge and technological advances over many years that, with only a few exceptions, have not been associated with the aura of fundamental physics breakthroughs. Nonetheless, the impact of numerical weather prediction is among the greatest of any area of physical science. As a computational problem, global weather prediction is comparable to the simulation of the human brain and of the evolution of the early Universe, and it is performed every day at major operational centres across the world.

1,475 citations

Journal ArticleDOI
TL;DR: Satellite-derived total-column AOD, when combined with a chemical transport model, provides estimates of global long-term average PM2.5 concentrations, with significant spatial agreement with ground-based in situ measurements.
Abstract: BackgroundEpidemiologic and health impact studies of fine particulate matter with diameter < 2.5 μm (PM2.5) are limited by the lack of monitoring data, especially in developing countries. Satellite...

1,401 citations

Journal ArticleDOI
TL;DR: In this article, a survey of sensors and sensor systems for gaseous ammonia is presented, where the authors present different application areas for ammonia sensors or measurement systems and different techniques available for making selective ammonia sensing devices.
Abstract: Many scientific papers have been written concerning gas sensors for different sensor applications using several sensing principles. This review focuses on sensors and sensor systems for gaseous ammonia. Apart from its natural origin, there are many sources of ammonia, like the chemical industry or intensive life-stock. The survey that we present here treats different application areas for ammonia sensors or measurement systems and different techniques available for making selective ammonia sensing devices. When very low concentrations are to be measured, e.g. less than 2 ppb for environmental monitoring and 50 ppb for diagnostic breath analysis, solid-state ammonia sensors are not sensitive enough. In addition, they lack the required selectivity to other gasses that are often available in much higher concentrations. Optical methods that make use of lasers are often expensive and large. Indirect measurement principles have been described in literature that seems very suited as ammonia sensing devices. Such systems are suited for miniaturization and integration to make them suitable for measuring in the small gas volumes that are normally available in medical applications like diagnostic breath analysis equipment.

1,351 citations

Journal ArticleDOI
TL;DR: In this article, the authors present a recommended terminology to clarify the terms used for black carbon in atmospheric research, with the goal of establishing unambiguous links between terms, targeted material properties and associated measurement techniques.
Abstract: . Although black carbon (BC) is one of the key atmospheric particulate components driving climate change and air quality, there is no agreement on the terminology that considers all aspects of specific properties, definitions, measurement methods, and related uncertainties. As a result, there is much ambiguity in the scientific literature of measurements and numerical models that refer to BC with different names and based on different properties of the particles, with no clear definition of the terms. The authors present here a recommended terminology to clarify the terms used for BC in atmospheric research, with the goal of establishing unambiguous links between terms, targeted material properties and associated measurement techniques.

817 citations