ARISE - Atmospheric Dynamics Research InfraStructure in Europe

<p>The Atmospheric dynamics Research InfraStructure in Europe (ARISE) project has integrated different meteorological and geophysical station networks and technologies providing observations from the ground to the lower thermosphere. A particular emphasis is on improving observations in the middle atmosphere, as this is a crucial region affecting tropospheric weather and climate. Besides supporting innovative prototypes of mobile lidars and microwave radiometers, ARISE utilized the global infrasound network developed for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification, the lidar Network for the Detection of Atmospheric Composition Change (NDACC), meteor radars, wind radiometers, ionospheric sounders and satellites.</p> <p>This presentation highlights the objectives and results as well as perspectives of the first two project phases – one within the European Union’s 7th Framework Programme and the second within the Horizon 2020 programme. ARISE has facilitated multi-instrument stations and collocated measurement campaigns at different latitudes in Europe, including the observatories ALOMAR in northern Norway, OHP in southern France and Maïdo on Reunion Island (France), as well as the infrasound station in southern Germany. One ARISE study, for instance, analyzed different ground-based and space-borne observation technologies, revealing systematic biases for temperature and wind in both analysis and reanalysis models. Such biases are critical to the CTBT verification when validating infrasound signal detections by propagation modelling. Also, the potential of infrasound to be assimilated in weather or climate models was proposed, as infrasound can be used to probe winds and cross-wind effects in the middle atmosphere. Meanwhile, offline assimilation tests relying on infrasound data from ground-truth explosion events and wind data of ECMWF’s ERA5 model have been conducted. Overall, the interest of ARISE is to provide atmospheric data products and services for both scientific and civilian-security applications, including the monitoring of extreme events that have an atmospheric signature, such as meteors, thunderstorms or volcanic eruptions. For early warnings on volcanic eruptions, the Volcano Information System (VIS) was proposed as an ARISE product in cooperation with the CTBT organization and the Toulouse Volcanic Ash Advisory Center (VAAC).</p>

The National Data Centre Preparedness Exercise NPE 2019 - Scenario design and expert technical analyses

<p>For detection of non-compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT) the global International Monitoring System (IMS) is being built up and nearly complete. The IMS is designed to detect and identify nuclear explosions through their seismic, hydroacoustic, infrasound, and radionuclide signature. The IMS data are collected, processed to analysis products, and distributed to the signatory states by the International Data Centre (IDC) in Vienna. The member states themselves may operate National Data Centers (NDC) giving technical advice concerning CTBT verification to their government. NDC Preparedness Exercises (NPE) are regularly performed to practice the verification procedures for the detection of nuclear explosions in the framework of CTBT monitoring. The NPE 2019 scenario was developed in close cooperation between the Italian NDC-RN (ENEA) and the German NDC (BGR). The fictitious state RAETIA announced a reactor incident with release of unspecified radionuclides into the atmosphere. Simulated concentrations of particulate and noble gas isotopes at IMS stations were given to the participants. The task was to check the consistency with the announcement and to serach for waveform events in the potential source region of the radioisotopes. In a next step, the fictitious neighbour state EASTRIA provided further national (synthetic) measurements and requested assistance from IDC with so called Expert Technical Analysis (ETA) about the origin of those traces. The presentation shows aspects of scenario design, event selection, and forward amospheric transport modelling as well as radionuclide and seismological analyses.   </p>

IDC events related to volcanic activity at Kamchatka Peninsula

<p>International Monitoring System (IMS) is designed to detect and locate nuclear test explosions as part of Comprehensive Nuclear Test-Ban Treaty (CTBT) verification regime. This network can be also used for civil applications, such as the remote monitoring of volcanic activity.</p><p>Events related to volcanic eruptions, which are listed in the International Data Centre (IDC) bulletins, are typically detected by infrasound stations of the IMS network. Infrasound station IS44 and primary seismic station PS36 are situated in Kamchatka, Russian Federation, in the vicinity of several active volcanoes. These two stations recorded seismo-acoustic events generated by volcanic eruptions. In addition to atmospheric events, the IMS network has the potential of detecting underwater volcanic activity. Under favourable conditions, the hydroacoustic stations located in the Pacific Ocean and PS36 may detect underwater events close to the shore of Kamchatka Peninsula.</p><p>The aim of this presentation is to show examples of volcanic eruptions at Kamchatka Peninsula recorded by the IMS network. Supplementary information obtained by other observing networks can be found in reports issued by Kamchatkan Volcanic Eruption Response Team (KVERT) or Tokyo Volcanic Ash Advisory Center (VAAC). Such information can be compared with events listed in IDC bulletins.</p>

The Mount Meron infrasound array: an infrasound array without a noise reduction system

SUMMARY Measurements of seismo-acoustic events by collocated seismic and infrasound arrays allow for studying the two wavefields that were produced by the same event. However, some of the scientific and technical constraints on the building of the two technologies are different and may be contradicting. For the case of a new station, an optimal design that will satisfy the constraints of the two technologies can be found. However, in the case of upgrading an existing array by adding the complementing technology, the situation is different. The site location, the array configuration and physical constraints are fixed and may not be optimal for the complementing technology, which may lead to rejection of the upgrade. The International Monitoring System (IMS) for the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) includes 37 seismic arrays and 51 infrasound arrays. Although the CTBT verification regime is fixed in the treaty, an upgrade of the existing arrays by adding more technologies is possible. The Mount Meron seismic array (MMAI), which is part of the IMS, is composed of 16 sites. Microbarometers were installed at five MMAI sites to form the Mount Meron infrasound array. Due to regulation and physical constraints, it was not possible to relocate the sites nor to install analogue noise reduction filters (i.e. a pipe array). In this study, it is demonstrated that the installation of the MMAI infrasound array is beneficial despite the non-optimal conditions. It is shown that the noise levels of the individual array sites are between the high and median global noise levels. However, we claim that the more indicative measures are the noise levels of the beams of interest, as demonstrated by analysing the microbaroms originated from the Mediterranean Sea. Moreover, the ability to detect events relevant to the CTBT is demonstrated by analysing man-made events during 2011 from the Libya region.