J. F. Prieto

Ozone Modelling Over A Large City By Using A Mesoscale Eulerian Model: Madrid Case Study

An Air Quality Model has been applied over the mesoscale urban area of Madrid (Spain). The Model is composed on different modules: a mesoscale meteorological module REMEST which solves the Navier-Stokes equation system over the Madrid domain. This model is running under the non-hydrostatic option and is the main code of the system. The model solves the prognostic equations by using an Eulerian approach and integrated an eulerian transport equation which is solved simultaneously. The meteorological module provides the wind speed, direction, temperature and humidity on a three dimensional domain at very short time steps (a few seconds). The model uses a 14 different landuse types which are obtained by using the REMO module which uses the information provided by the LANDUSE satellite image over the area with 30 m spatial resolution. The model transport the emitted pollutants into the domain and deposit them over the domain. The emission module EMIMA takes into account the point, line and area emissions over the area. Special importance is given to the biogenic emissions which are obtained by using the satellite landuse classification for caducous, perenneal and mixed terrain. The emission module considers the EPA and CORINAIR emission factors and is 250x250 m spatial resolution and 1 hour temporal resolution. The deposition module DEPO uses the resistance approach Transactions on Ecology and the Environment vol 10,

GPS monitoring in the N-W part of the volcanic island of Tenerife, Canaries, Spain: Strategy and results

This paper describes design, observation methodology, results and interpretation of the GPS surveys conducted in the áreas of the N-W of Tenerife where deformation was detected using InSAR. To avoid undesirable antenna positioning errors in the stations built using nails, we designed and used calibrated, fixed-length metal poles, allowing us to guarantee that the GPS antenna was stationed with a height repeatability of the order of 1 mm and of less than 3 millimeters on the horizontal plañe. The results demónstrate that this system is ideal for field observation, especially to detect small displacements that might be masked by accidental errors in height measurements or centering when observed with a tripod. When observations were processed, we found that using different antenna models in the same session sometimes causes errors that can lead to rather inaccurate results. We also found that it is advisable to observe one or two stations in all the sessions. The results have reconfirmed the displacement in the Chío deformation zone for the period 1995-2000 and indicate a vertical rebound from 2000 to 2002. They also confirm that the subsidence detected by InSAR to the south of the Garachico village has continued since 2000, although the magnitude of the vertical deformation has increased from around 1 cm to more than 3 cm a year. Detected displacements could be due to groundwater level variation throughout the island. A first attempt of modelling has been made using a simple model. The results indicate that the observed deformation and the groundwater level variation are related in some way. The obtained results are very important because they might affect the design of the geodetic monitoring of volcanic reactivation on the island, which will only be actually useful if it is capable of distinguishing between displacements that might be linked to volcanic activity and those produced by other causes. Even though the study was limited to a given área of Tenerife, in the Canary Islands, some conclusions apply to, and are of general interest in similar geodynamic studies.

Sensitivity Study Of Dry Deposition Fluxes In ANA Air Quality Model Over Madrid Mesoscale Area

The importance of an adequate parameterization of the deposition processes for simulation of three dimensional pollution fields in a mesoscale context is out of any doubt. An accurate parameterization of the deposition flux is essential for having a precise de termination of the flux removal and also for allowing longer simulation periods of the atmospheric processes. In addition, an accurate deposition patterns will allow a much more precise diagnostic of the impact of different pollutants on the different types of terrain actually present in complex environments such as the urban ones and their environs. health and toxic effects are critically dependent on accurate evaluation not only of air concentrations but also on deposition fluxes. In this contribution, we have implemented a complex resistance deposition model into an Air Quality System (ANA) applied over a large city such as Madrid (Spain). The model domain is 80x100 km which is much larger than the actual urban domain. The ANA model is composed on four different modules: a meteorological module which solves numerically the Navier-Stokes equations and predicts the wind, temperature and humidity three dimensional fields every time step; the emission module, which produces the emissions every hour and with a high spatial resolution (250 x 250 m) and with landuse information (for biogenic emissions) from the Landsat-5 satellite image; a photochemical module, which is based on the CBM-IV mechanism and solved numerically by following the SMVGEAR method and finally, a deposition module which is the based on the resistance approach. A dry deposition flux field experiment carried out in the Cuatro Vientos Madrid Military Airport located in the suburban area of Madrid and different pollution monitoring stations are used to compare modelling results with observed data. In addition, measured ozone vertical profiles are compared to ANA simulated ozone vertical profiles in the Madrid University district. Erisman et al (1994) and Wesely (1989) deposition parameterizations are used and compared. Results show a high sensitivity of Air Quality Models to deposition parameterizations. Comparisons show a good agreement between observed and simulated data.

Integrated Environmental Monitoring,Forecasting And Warning Systems InMetropolitan Areas (EMMA): MadridApplication

EMMA project, -an European Union DGXIII project-, is dealing with the development, test and validation of innovative telematics system for the monitoring and forecasting of air pollution in urban areas. Telematics components including multimedia products and services are extensively used in the project: a) specialized networks, b) CIS and Multimedia archiving systems and high definition terminals. Pollution and weather data are collected through highly automated telematics networks from all fixed stations in the metropolitan area. These data are stored in integrated relational databases and are analyzed and distributed according to EMMA architecture and presented in a user-friendly way using graphical tools. Madrid is a demo site in the EMMA project. Observations of SO^ NO*, (%, CO, PM10, Aromatic and radioactivity are used together with humidity, wind, Transactions on Ecology and the Environment vol 13,

Accurate ozone prognostic patterns for Madrid area by using a high spatial and temporal eulerian photochemical model

The ANA Air Quality Model (ANA stands for Atmospheric Mesoscale Numerical Pollution Model for Regional and Urban Areas) has been applied over Madrid during a five day period in June, 1995. The domain is 80 × 100 km2 and the spatial resolution is 2000 m. The ANA system is driven by a meteorological model REMEST and it includes a detailed emission model for anthropogenic and biogenic sources with 250 m spatial resolution and 60 minutes temporal resolution. Different deposition processes are used such as the Wesely (1989) and Erisman et al. (1994) resistance approaches and the simple aerodynamic resistance. The photochemical processes and the general chemistry is based on the CBM-IV mechanism for the organic compounds and solved by the SMVGEAR method (CHEMA module).The model uses 14 different landuse types which are obtained by using the REMO module which uses the information provided by the LANDSAT-5 satellite image over the domain. The emission module EMIMA takes into account the point, line and area emissions over the domain. Special importance is given to the biogenic emissions which are obtained by using the satellite landuse classification for caducous, perenneal and mixed terrain. The emission module considers the EPA and CORINAIR emission factors. The results show an accurate prediction of the ozone maxima for the five days and also the general pattern of the ozone observed data. The five day simulation is characterized by a local low pressure over the Madrid Area and high pressures over Spain and West of Europe. The ozone surface patterns show the diurnal cycle and the maxima concentrations up to 140-160 ppb for suburban areas during afternoon hours. The general performance of the model is considered quite good. The computer power requirements continue to be very high for standard workstations. Future progress on parallel platforms should improve considerably the computer time requirements.

Surface deformation studies of Tenerife Island, Spain from joint GPS-DInSAR observations

This work presents results for the three-dimensional displacement field at Tenerife Island calculated from campaign GPS and ascending and descending ENVISAT DInSAR interferograms. The goal of this work is to provide an example of the flexibility of the technique by fusing together new varieties of geodetic data, and to observe surface deformations and study precursors of potential activity in volcanic regions. Interferometric processing of ENVISAT data was performed with GAMMA software. All possible combinations were used to create interferograms and then stacking was used to increase signal-to-noise ratio. Decorrelated areas were widely observed, particularly for interferograms with large perpendicular baseline and large time span. Tropospheric signal was also observed which significantly complicated the interpretation. Subsidence signal was observed in the NW part of the island and around Mount Teide and agreed in some regions with campaign GPS data. It is expected that the technique will provide better results when more high quality DInSAR and GPS data is available.

Use of the gyrotheodolite in underground networks of long high-speed railway tunnels

The quality of geodetic networks for guiding Tunnel Boring Machines (TBMs) inside long tunnels depends largely on the correct use of a gyroscope. These networks are based on a series of control points at the tunnel entrance, and link each station by means of survey observations as they advance along the tunnel. Once, the networks are used to guide the TBM, they are no longer checked again. It is necessary to perform high accuracy astronomical observations to stars in order to determine the gyrotheodolite constant. Since astronomical observations cannot be made inside tunnels, geodetic azimuths have to be used for the computations. However, these azimuths cannot theoretically be compared with the astronomical azimuths obtained by the gyrotheodolite. An alternative is to compute the instrument constant using the values of the deviation of the vertical derived from a geoid model. That is the approach used in this work where a methodology for the design of underground networks in long tunnels is also presented. This procedure has been implemented during the construction of the Guadarrama and Pajares high-speed railway tunnels (Spain).

Characterization of Cavities Using the GPR, LIDAR and GNSS Techniques

The study of the many types of natural and manmade cavities in different parts of the world is important to the fields of geology, geophysics, engineering, architectures, agriculture, heritages and landscape. Ground-penetrating radar (GPR) is a noninvasive geodetection and geolocation technique suitable for accurately determining buried structures. This technique requires knowing the propagation velocity of electromagnetic waves (EM velocity) in the medium. We propose a method for calibrating the EM velocity using the integration of laser imaging detection and ranging (LIDAR) and GPR techniques using the Global Navigation Satellite System (GNSS) as support for geolocation. Once the EM velocity is known and the GPR profiles have been properly processed and migrated, they will also show the hidden cavities and the old hidden structures from the cellar. In this article, we present a complete study of the joint use of the GPR, LIDAR and GNSS techniques in the characterization of cavities. We apply this methodology to study underground cavities in a group of wine cellars located in Atauta (Soria, Spain). The results serve to identify construction elements that form the cavity and group of cavities or cellars. The described methodology could be applied to other shallow underground structures with surface connection, where LIDAR and GPR profiles could be joined, as, for example, in archaeological cavities, sewerage systems, drainpipes, etc.

A sensitivity analysis of a high resolution emission model under different emission scenarios over Madrid area

Emission models are a key module of the Air Quality Systems particularly in the care of modelling the pollutant air concentrations in urban areas. The necessity of detailed emission models is an essential requirement of having an accurate and sensitive Air Quality System to predict the air concentrations on detailed spatial and temporal distribution. Recently, the biogenic emissions have been incorporated in detailed emission models to take into account its influence on the VOC budget. Different emission scenarios are applied into an Air Quality Model (ANA) over Madrid Area. Anthropogenic and biogenic emissions are included in the 250x250 emission model. The Air Quality System takes into account a detailed resistance deposition approach for different pollutants, a LANDSAT satellite landuse classification, an Eulerian Transport Model and a complex detailed mesoscale non-hydrostatic model REMEST. The different emission scenarios are applied to June, 5-7, 1995 period after validating the emission model with observed concentrations at different urban stations. Results show that increase and decrease simulations produce decrease or increase values of ozone in function of the increase (or decrease) percentages and depending on the absolute values of ozone. The results suggest that important reductions on NO x and VOCs may lead to increments in ozone levels in urban areas. More important reductions in those emissions can lead to reductions in ozone levels. Important increases in those emissions lead to substantial reductions in ozone levels.

Sea Bottom Classification by Means of Bathymetric LIDAR Data

Light Detection and Ranging (LIDAR) provides high horizontal and vertical resolution of spatial data located in point cloud images, and is increasingly being used in a number of applications and disciplines, which have concentrated on the exploit and manipulation of the data using mainly its three dimensional nature. Bathymetric LIDAR systems and data are mainly focused to map depths in shallow and clear waters with a high degree of accuracy. Additionally, the backscattering produced by the different materials distributed over the bottom surface causes that the returned intensity signal contains important information about the reflection properties of these materials. Processing conveniently these values using a Simplified Radiative Transfer Model, allows the identification of different sea bottom types. This paper presents an original method for the classification of sea bottom by means of information processing extracted from the images generated through LIDAR data. The results are validated using a vector database containing benthic information derived by marine surveys.