Two technicians from Ecuador and Peru will attend a technical training at the facilities of LEONARDO in Neuss, Germany. The training serves to improve understanding of the Radar Hardware, and helps to enable maintenance and repair works at the Radar sites independent of the Manufacturers support. ... This training is part of the after-sales service and focuses on configuration of software setup, Hardware diagnosis and general system understanding. Also, the two scientist will visit the LCRS in Marburg for discussions of project related issues. At this opportunity they will present their recent scientific progress and future plans.
Freezing rain and high windspeeds at the extreme altitude of 4550 m caused a complete icing of the whole Radar station CAXX in the Cajas National park. ... Although the Radar itself is immune to such weather attacks, the high voltage line is not - and was ruptured along its track. In consequence all system went offline and some of the more delicate electronics have been damaged by the induced spikes of voltage. Also the prolonged period without power creates problems with moisture condensing in the high frequency components. The utility company will reestablish electricity as soon as possible to bring the system back into operation. The operator ETAPA EP will then adress required maintenance work.
RadarNetPlus is now complete with the new Radar station in Piura at the Campus of the UDEP. ... After several delays in manufacturing and a
long trip across the Atlantic ocean the new system finally arrived by road transport at its destination.
Assembling Antenna and Radom on the support structure
The Tower was already prepared months earlier, but still some final adjustments had to be made, before the tense moment of lifting the expensive antenna on top of the structure came.
Crane service was required for the assembled antenna with almost 500 kg
Mario Guallpa, the responsible Engineer for the Radar in Cuenca joined the team of UDEP for the initial setup and first operational tests. But as the climate in Piura is extremely arid and the rain season just had passed, the operators had to wait until the mid of May 2019 to see the first rain showers in the radar display:
isolated light rain above the Sechura Desert
Visiting all involved Universities and the operating authorities of the Radars, Rütger Rollenbeck traveled from Cuenca down to Piura. ...
The agenda was packed with presentations and discussions, covering topics like operational issues, the development of a trinational cooperation between Ecuador, Peru and Germany and the
current climatic situation in South-America. With the new Radar in Piura still awaiting arrival, the scientific work focuses on preparing the older Radar station for restart and analyzing
episodes of heavy rainfall observed in 2014 to 2017. While in Cuenca and Loja the urban hydrology is an important topic, the arid south-west of Ecuador is more affected by torrential rain
and the consequent floodings, erosion and water management issues. Actually, the annual mean rainfall in the south-west of Ecuador is sufficient (about 500 mm per year) for agricultural activities
Nevertheless, the temporal and spatial distribution is unfavorable and requires a deeper understanding only possible with the integral observation capabilities of Rain Radar.
Andy Fries studying the configuration
At the Radarsite near Loja (LOXX), the software configuration had to be adapted and some minor components needed replacement. Fortunately, the weather was favorable and in such conditions the mountain Pass El Tiro is always a refreshing and pleasant place to be. After a few tests the Radar was restarted and images were recorded for later analysis.
First raw images: No rain, just clutter and noise
A surprise came, when a few days later the team visited the Radarsite near Celica (GUAXX), some 4 hours to the west of Loja. Winding up the long gravel road from the Panamericana to the mountain top smoke appeared above the hill side. Actually, the whole south side of the peak of Guachaurco had been burnt down and still some flames were smoldering along the track.
The whole mountain flank burned up
To our big relieve, the flames had stopped just short of the many technical installations on that mountain including our weather radar RS 120. What was damaged however, was the power line and so we had to wait a while, before we could test the new UPS (110 kg!) we had brought along. EERSA, the local utility company was busy (while initially not at all lucky) replacing burnt powerlines. After that, guided by our electrician, we reinstalled the whole mains voltage supply for the RS 120 and improved several shortcomings of the initial installation, mainly by cutting out unneeded cable lengths.
The brave guys of EERRSA: breathing smoke in the thin air 3000 m above sea level
The long delay took us into the evening hours before the work was finished, so further issues had to be postponed for the next maintenance visit. After all it´s kind of challenging, going down a gravel road carved into a very steep mountain side with a total drop of almost 1000 m in a heavy Pickup-Truck. Even more so, when darkness falls. There is a reason why the locals use their mules.
The Conference Trip was continued in Piura, where the recently installed tower and the impressive service container installation was inspected. During several meetings and workshops, tasks were, and responsible personnel was introduced and the details of the scientific agenda were defined. Especially the topic of ENSO and its strange behaviour in 2017 with heavy floodings during a normally dry period was discussed. As a final act, the signing of the new cooperation agreement was celebrated and the financial support of the Phillips-Universität Marburg was acknowledged.
Cooperation agreement signed: Universität Marburg gets full acces to future Radar data by contributing financially to the installation
The basis of the RadarNetPlus- Project is the X-Band weather Radar Technology ... The majority of weather Radars
used worldwide operate in the S- and C-band (2.6 to 5.8 GHz). X-band (roughly 8 - 12 GHz) has some advantages for the use-case of RadarNetPlus: Its is economically more feasible
due to smaller antenas and simpler electronic implementation and has a much higher sensitivity for smaller rain droplets (i.e. drizzle). This advantage is also its main drawback: X.band suffers
from a much higher attenuation of the waves traveling through the atmosphere, and hence the range is much more limited. However, in mountain terrain like the Andes, the range of Radar is limited anyway
by blocking the beam, so x-Band is appropriate for this project. Also, the higher sensitivity allows for a better spatial resolution, a fact which supports the observation of the highly heterogeneuos
rainfall distribution in this complex region. And it also is better suited to the needs of small-scale ecological studies, reproducing differences in precipitation on short distances.
Another limitation of the Radars in this economic range is that they supply no Doppler or polarimetric information and have only one scan elevation, so only a constant altitude plan position indicator (CAPPI)
is generated. LEONARDO therefore prefers to call their system a rain scanner.
The DHI LAWR
DHI (Dansk Hydraulisk Institut) of Denmark produced the LAWR (Local area weather Radar) between 1998 and 2015, mainly with the intention to supply a system for the needs of typical urban hydrology applications. Our system was delivered in 2001 and installed in March 2002 above the ecological research site Reserva Biologica San Francisco to monitor rainfall specifically in the Valley of the Rio San Francisco, east of Loja. As a small fun-fact, the system was ordered with a range of 30 km, but shortly after start of operation it turned out, that it offered double the range. During the first years of operation it was constantly upgraded and quite a few software bugs and hardware-shortcomings were corrected. The chosen site offered almost perfect unobstructed view of the eastern escarpment of the Andes in that region. But the site also caused significant stress on all Hardware due to the extremely humid conditions there and the difficult access made maintenance a challenging task. Legal matters forced a longer standstill in 2008 which left the Radar system inoperable. The whole system was dismantled and the new site El Tiro was chosen, where operation could be resumed in 2012.
Antenna and head unit (left), FURUNO Radar display and the two attached Computers
The LAWR (as well as the RS 120) is based on a standard marine Radar of the type FURUNO 1500 and the reflectivity information is derived from the video signal normally going into the navigation display of the Radar. The video-signal is sampled with 20 Mhz and digitized in polar format to a 10-bit numerical resolution. From these raw images, a proprietary software resamples three cartesian images in 8-bit resolution with 500 m resolution and 60 km range, 250 m and 30 km and 100 m 15 km. The sampling card can be adjusted for sensitivity and low-cutoff, to optimize the signal-to-noise ratio. The output signal is proportional to linear reflectivity but strongly varies with technical conditions of the system and atmospheric influences. Hence, the signal as is can not be directly converted to reflectivity (nor rain rate), but needs a complex pre-processing. The limited range of the LAWR is also a consequence of the antena used, which is so robust, that it does not need a radome, but is also not well suited for rainfall observation. With a vertical aperture of 20° (horizontal: 1°), the strong attenuation of X-band-waves is even more expressed and during stronger rain storms the useful range sometimes shrinks to 30 km.
The Gematronik / LEONARDO RS 120
LEONARDO (former: SELEX Gematronik) of Germany improved strongly on the basic marine Radar from FURUNO by combining the basic head unit with a better-suited pencil-beam antenna. This improves the attenuation susceptibility strongly, thus supplying the RS 120 (Rainscanner with 120 cm Antenna diameter) with a nominal range of 100 km, that even in strong rainstroms does not drop below 60 km. Also, the original Radar display from FURUNO is replaced by a newly designed processing and control board and some minor modifications are done to adjust the signal-to noise ration to the requirements of precipitation observation. The system has a much more elaborate scan strategy and uses a slower antenna rotation. The preprocessed output consists of polar 8-bit data of reflectivity (dBZ) where major geometric corrections are already applied in the manufacturer supplied software-tandem of RainView and RainViewAnalyzer. Raw data as well as derived cartesian products (Plan position indicator) for display are stored according to the user-configurable settings. All three systems currently in use in RadarNetPlus are close to identical. Due to the much larger antenna, RS120 needs a Radome and a stronger support structure.
RS 120 Antenna and head unit (left), Control unit and Data processor (right)
Technical specifications of the Radar Systems. The new system in Piura (S05°10' / W080°38' / 42 m) has identical values
In July 2018 the new Project: "High-resolution Radar analysis of precipitation extremes in Ecuador and North Peru and implications of the ENSO-dynamics" was approved by DFG to
Principal Investigator Rütger Rollenbeck for an initial duration of three years ...
RadarNetPlus is the follow-up of RadarNetSur and extends the observed area by almost 35000 square kilometers with the implementation of an additional RS120 Radar instrument in Piura / North Peru.
The aim of RadarNetPlus is the observation and analysis of regional precipitation extremes and the associated atmospheric dynamics of circulation in the meteorologically complex transition zone from the coastal plains of southern Ecuador and northern Peru across the Andes to the eastern foot zone of the mountains. A longer time series from 2014 to 2020 of the weather radar systems of RadarNetSur allows to identify and explain relevant spatio-temporal patterns like persistent, transient end episodic cycles. The diurnal cycle is shaped by small-scale local circulation systems like the mountain-valley-, the land-sea-breeze or the confluence of synoptical flows and katabatic winds. They lead to a characteristic pattern of precipitation genesis, which cannot be registered by point observations. In Radar imagery they show up in detail and their spatial distribution will be visible. This enables to understand the high heterogeneity of the diurnal cycle and the occurrence of extremes as dependent on the topography.
Dependent on the synoptic wind situation such patterns also change their location. This superordinate control in its spatial extent can only be observed by weather radar by deriving typical spatio-temporal patterns in relation to the larger-scale weather situation. As a result, detailed maps of the diurnal and annual cycle of precipitation and areas with a high potential for extreme events are generated.
The arid climate of the coastal regions is caused by large scale subsidence, but episodically deep convection occurs. Convective cells with extreme precipitation are propagating eastwards and cause local flooding, more frequently in the southern sub-regions. Genesis and typical pathways are analyzed by using profiles of precipitation intensity and associated dynamic convergence zones, which form during such events. The movement profile of such dynamic convergence zones is indicative for the relation of their genesis to the synoptical and spatial context and shows areas of elevated risk for extreme events. Also, regional differences of the whole study region caused by topography and general exposition are shown. Regional differences are also an important aspect of the longer-term influence on the genesis of extreme precipitation. For each sub-region the effect of temperature anomalies of the costal (El-Niño-region 1+2) and central pacific (EN-region 3+4) will be analysed, especially their modifying influence on local precipitation enhancement by topographic and synoptic factors.
RadarNetPlus will cover about 90000 square kilometers in Ecuador and Peru
The previous Project RadarNetSur was started in 2012 as Technology Transfer Project. It was aimed to apply knowledge to a wider area which was gained in the very first ecuadorian Project PREDICT (Precipitation dynamics and chemical properties) executed by the Universität Marburg. It scope was to implement Radar Technology at two additional sites in Cuenca and the arid south-west of the Province of Loja. The assignation and preparation of the sites as well as manufacturing and shipping of the Radars took some time. Only the LOXX Radar system, which had been used previously in the PREDICT-Project was ready in the first year, after it was completely refurbished to serve at its new site El Tiro on the mountain pass between Loja and Zamora. This system went online in October 2012 under supervision from the UTPL and supported by LCRS. The site is perfectly chosen to observe the Valley of the Rio San Francisco, where long-term ecological research is executed on behalf of the german research platform RESPECT. The western half of the Radar range allows for a detailed monitoring of precipitation above all of the provincial Capital Loja and also the Muncipial Airport in Catamayo.
Radarsite LOXX shortly after installation
The first additional Radar to come into operation was GUAXX in March 2014. Sited at the Cerro Guachaurco at 3000 m above sea level, this Radar system has a superior overview above the whole area of South-West Ecuador from the Andes to well beyond the Pacific coast, also covering parts of North Peru.
Radarsite GUAXX shortly after installation
Gobierno Provincial de Loja took over the responsibility for the preparation, realization and operation of this system, strongly supported by the local scientific coordinator Andreas Fries affiliated to the LCRS of Universität Marburg and the Universidad Tecnica Particular de Loja. In March 2015, the demanding task of setting up CAXX in the National Park Cajas was finished. The 4550 m high Cerro Paragüillas as chosen site makes this the highest weather Radar in the world - and the extreme conditions there with low air density, high wind speeds and frequent cloudiness with occasional icing fog makes the additional delay understandable. In charge of setup and operation is ETAPA EP the muncipial utility and telecommunication provider of Cuenca. The chief responsible scientist Mario Guallpa was supported by staff of ETAPA, the Universidad de Cuenca and of course Andy Fries.
Radarsite CAXX: Finalizing the installation at 4550 m
After the installation of the Radars, the communication and telemetry was added, passing the received radar images each five minutes to a central server operated by GPL in Loja. Data is also stored in Cuenca at ETAPA, at the UTPL and the LCRS in Germany. The start of operation came just in time, to monitor a heavy flooding event on the Pacific coast in South Ecuador. Although not uncommon in this region, the local population there suffered many fatalities and strong damage to public infrastructure and private property occured. It is one goal of RNP, that Radar monitoring of developing heavy rain events helps to mitigate the impact of such episodes.
The March 2015 flooding event as monitored by RadarNetSur
The first weather Radar installed in Ecuador was the system of the type DHI LAWR now operating as LOXX. In 2002 this was installed with the purpose to improve high resolution rainfall measurement especifically for the ecological research work going on in the 900-hectare area Reserva Biologica San Francisco. Here, a common effort of german Universities together with ecuadorian partners is aimed at studying a broad array of ecological factors and phenomena on multiple scales and for extended periods. The DHI LAWR was deployed to the highest Mountain in that research area, the Cerro de Consuelo (3080 m). The extremely humid climate of this mountain and the semi-prototype state of the instrument made this a difficult task, also considering, that initially data had to be downloaded to CD´s weekly by hand and carried four hours downhill in a backpack to the research station. Nevertheless, six good years of Radar data could be obtained and important methodological progress was made in adressing the operational circumstances of weather Radar in tropical mountains.
Coverage of LOXX Consuelo comparing the interpolated observations of meteorological stations and a calibrated Radar product for 2002 - 2008
RadarNetPlus is build on almost 18 years of experience with weather Radar in South America and hopefully will contribute to a deeper understanding of the regional circumstances that affect temporal and spatial rainfall distribution. Especially, conditions that cause heavy rain events are important to understand in this region of the world which is the one single region most affected by the ENSO-phenomenon. In the meantime, several other entities have joined the projects initiative. Beyond the founding members the Universität Marburg with the LCRS, the National weather service of Ecuador INAMHI and the UTPL, now ETAPA EP in Cuenca is a reliable partner suppported by the Universidad de Cuenca. In Loja GPL has passed operational duties to UTPL, but still contributes with administrative and logistics support. With the association of the Partners at UDEP in Piura North-Peru, a whole array of supporters are now involved: the Ministerio de la Produccion in Lima, who has funded the major part of the new Radar in Piura, SENAMHI, the national weather service of Peru, the instituto Geofisico (IGP) de Peru, the University of Newcastle in the UK, and the national company Petroperu as well as Asociacion Peruana de productores y exportadores de Mango (APEM).
Cooperation Partners in RadarNetPlus
RadarNetPlus is maintained and operated by a Team of scientists and technicians from Universities and authorities in Ecuador, Peru and Germany