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The latest generation of active and passive ground-based remote sensing instruments, often called “profilers”, has shown its potential for continuous and high-resolution measurements of thermodynamic and kinematic vertical profiles as well as particle-related profiles. It is precisely these observations of the atmospheric boundary layer that are increasingly needed to improve the forecast quality of high-resolution numerical weather prediction (NWP) and nowcasting.

For this purpose, the DWD has initiated the project “Pilotstation” to evaluate options for a qualitative network expansion with suitable surface remote sensing profilers. Currently, we assess the following profilers in a dedicated testbed at Lindenberg Observatory: Doppler lidar, microwave radiometer, water vapor broadband-DIAL, and cloud radar. Furthermore, we plan to evaluate a compact Raman lidar in the future. At DWD, the assessment of candidate systems takes place holistically focusing on all aspects of instrument reliability, operational sustainability, data quality, and on the potential benefit for the NWP using assimilation experiments. This implies efforts to standardize data processing steps and data formats, the development of software tools to support network operations and the proper integration of the observations in the data assimilation system. After the initial testing and evaluation at the Lindenberg Observatory, a suite of instruments will be installed at the weather station in Aachen-Orsbach to enable an end-to-end testing in an operational framework.

We give an overview of the ongoing project and present results regarding the various aspects: operations and sustainability, data quality and assimilation tests for the different testbed instruments and observations. This contribution complements the efforts of network development for future operational use within the frame of the EUMETNET's E-PROFILE observations program and the COST action PROBE.

How to cite: Knist, C., Kayser, M., Löffler, M., Vural, J., Schomburg, A., Görsdorf, U., Lauermann, F., Leinweber, R., Klink, S., and Lehmann, V.: DWD Pilotstation – Evaluating ground-based remote sensing systems for future observing networks, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-119, https://doi.org/10.5194/ems2022-119, 2022.

EUMETNET's E-PROFILE programme aims to gather, centrally process and deliver profiles of wind, temperature, humidity and aerosols including volcanic ash in near real-time. It consists of a data hub to collect process and distribute data while the instruments are owned and operated by EUMETNET members as well as partners from academia and industry. As of today, E-PROFILE integrates operationally 30 radar wind profilers and more than 400 automatic lidars and ceilometers (ALC) producing profiles of wind speed and direction and attenuated backscatter coefficient, respectively. Most radar wind profilers are assimilated into ECMWF's Integrated Forecasting System (IFS) and an extensive analysis of Forecast Sensitivity to Observation (FSO) data from ECMWF confirms the positive impact of those data on the forecast quality.  ALC data are calibrated centrally by E-PROFILE using natural atmospheric targets and provide a basic yet quantitative information of aerosols including volcanic ash and durst, which are considered airborne hazards for aviation. With more than 400 operational sites, E-PROFILE's ALC network is a valuable complement to satellite observations and surface based research lidar networks. In the current programme phase (2019 - 2023) we are working on an advanced processing chain to retrieve aerosol extinction coefficients and aerosol mass concentration from ALCs to better meet the user requirements. Finally, E-PROFILE has been tasked to integrate microwave radiometers and Doppler lidars and to collect, process and distribute temperature, humidity and wind measurements from these instruments. This new component of the E-PROFILE programme aims at filling the observational gap in the atmospheric boundary layer.  We present briefly the operational components of E-PROFILE, give a detailed update on the ongoing developments and highlight how E-PROFILE serves NWP and informs about airborne hazards.

How to cite: Haefele, A., Bircher-Adrot, S., Rüfenacht, R., Lehmann, V., Mattis, I., Mortier, A., Cimini, D., and Turp, M.: EUMETNET's E-PROFILE network for thermodynamic profiling and the detection of airborne hazards, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-623, https://doi.org/10.5194/ems2022-623, 2022.

The depth of the aerosol layer at the Villum Research Station at Station Nord in the high Arctic is analyzed based on eight years of observations from a ceilometer. The depth of the aerosol layer is assigned to the inflection point in the attenuated backscatter profile by two methods; one is based on polynomial approximation of the profile and the other is direct numeric differentiation. The analysis is based on two types of hourly profiles; one consists of averaging the attenuated backscatter observations and the other by computing the median. It is noted that the depth of the aerosol layer in the Arctic might be different from the depth of the turbulent layer near the ground.

Near the ground, the observed backscatter exhibits a pronounced seasonal variation, having low values during the summer and high values during the winter. The strength of the seasonal variability decreases with height and is virtually absent at 1 km.

Due to sporadic occurrence of outliers in the range between 50 m and 80 m in the ceilometer observations, this part of the profile is not used in this study. Restricting the observations to heights above100 m, the depths of the aerosol layer are found to be typically 230-250 m. It varies little between winter and summer, but the spread in the depth was larger during the winter as compared to summer.

To extend the profile of the attenuated backscatter below 100 m, the ceilometer measurements were combined with Carrier-To-Noise-Ratio observations from a Doppler wind Lidar. Thus, hourly profiles of attenuated backscatter starting at 40 m, are obtained. The results are available for 2018 only and they show aerosol-layer depths below 100 m as well as depths around 230-250 m and they show few observations of aerosol-layer depths between 100 m and 230 m.

Acknowledgement: This article is based upon work from COST Action CA18235 PROBE, supported by COST (European Cooperation in Science and Technology). www.cost.eu.

How to cite: Gryning, S.-E., Batchvarova, E., Floors, R., Münkel, C., Sørensen, L. L., and Skov, H.: Long-term ceilometer/wind-lidar observations of aerosol-layer depth in the Arctic, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-234, https://doi.org/10.5194/ems2022-234, 2022.

Air quality and meteorology in urban environments are strongly affected by dynamical processes occurring in the atmospheric boundary layer. Vertical ventilation, horizontal advection, and atmospheric stratification, largely driven by surface-atmosphere exchanges influence the transport of momentum, heat, moisture, gases, and aerosols.

To improve the understanding of these exchange processes in the urban atmosphere and the implications of spatial variations in topography, surface roughness, and surface cover; the 3-dimensional wind field is studied. In this work, we are reporting results of the novel “volume wind processing (VW)” software to retrieve horizontal wind information on a 3D spatial grid from observations of a single scanning Doppler wind lidar (Vaisala Windcube 400s). In the framework of the PANAME initiative (PAris region urbaN Atmospheric observations and models for Multidisciplinary rEsearch), the Doppler wind lidar is deployed on the rooftop of a tall building in central Paris, France, for the duration of two years. It is set to perform a series of scan strategies to monitor the vertical and horizontal variations of the mean wind field across the city center.

In addition to classical vertical wind profiling at the location of the lidar in Doppler Beam Swinging mode (DBS), 2D maps of horizontal wind speed are obtained from zero-elevation Plan Position Indicator (PPI) scans to assess spatial heterogeneity of the wind field. Further, the VW provides vertical profiles of horizontal wind to be derived at large distances (up to 7km) from the sensor using sector PPI scans at multiple elevation angles. It is the objective of this work to quantify the uncertainties in the VW products, to optimize the scan strategies considering spatial and temporal variations of the wind field, and to finally demonstrate their potential for a variety of applications.

Observations describing the horizontal and vertical variations in wind speed and direction, at high spatial resolution and continuous temporal coverage, are expected to greatly advance the process of understanding the urban atmosphere dynamics. These new generation data are also valuable for the evaluation of numerical simulations (weather and air quality), the quantification of wind energy resources, air traffic (e.g., drones) and sustainable urban design.

How to cite: Cespedes, J., Kotthaus, S., Thobois, L., and Haeffelin, M.: Deriving 3D wind fields in the Paris urban atmosphere from scanning Doppler lidar observations, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-676, https://doi.org/10.5194/ems2022-676, 2022.

The energy reaching the earth surface in form of solar radiation during the daytime is partly reflected as outgoing radiation, partly conducted into the ground and partly trans- ported into the atmosphere by turbulent eddies of various scales forming the convective boundary layer (CBL) during the daytime. The latter energy flux partitions into sensible heat flux H and latent heat flux L. The understanding of H and L profiles is decisive for correct atmospheric simulations with models since these profiles rule the heat and water budgets, the distribution of humidity and temperature, and thus the atmospheric stability and furthermore the formation of clouds and precipitation (Behrendt et al. 2020).

In recent years, it has been demonstrated that lidar, is capable of not only determining mean profiles and gradients in the daytime CBL, the interfacial layer, and the lower free troposphere above but also higher-order-moment profiles of turbulent fluctuations for more and more variables, like vertical wind, moisture, temperature, aerosol backscatter, horizontal wind and dissipation rate, taking advantage of the synergy between a Raman lidar (temperature, moisture and aerosol backscatter) and Doppler lidars (vertical and horizontal wind) (Wulfmeyer, et al. 2016).

In this regard, the Institute of Physics and Meteorology of the University of Hohenheim has developed a thermodynamic profiler based on the Raman lidar technique, namely the Atmospheric Raman Temperature and Humidity Sounder (ARTHUS) (Lange et al. 2019). ARTHUS can be operated on ground-based, ship-borne and airborne platforms.

Stable 24/7 operations over long periods were achieved during several field campaigns and at the Land Atmosphere Feedback Observatory (LAFO) at the University of Hohenheim accumulating almost a year of data until now and covering a huge variety of weather conditions. Two collocated Doppler lidars (one in vertically staring mode and a second one in a 6-beam scanning mode) give the horizontal and vertical wind components, needed for H and L calculations, as well as dissipation rate.

ARTHUS has been also deployed during the EUREC4A field campaign (Stevens et al, 2020), on board RV Maria S Merian, to study ocean-atmosphere interaction, (18 Jan to 18 Feb 2020), along with two Doppler lidars.

Between 15th July and 20th September 2021, ARTHUS was deployed at Lindenberg Observatory from the German Weather Service (DWD).

At the conference, L, H and dissipation rate case examples from these campaigns will be presented.

References

Behrendt et al. 2020, https://doi.org/10.5194/amt-13-3221-2020

Lange et al. 2019, https://doi.org/10.1029/2019GL085774

Stevens et al. 2021, https://doi.org/10.5194/essd-2021-18

Wulfmeyer et al. 2016, https://doi.org/10.1175/JAS-D-14-0392.1

How to cite: Lange Vega, D., Späth, F., Abbas, S., Behrendt, A., and Wulfmeyer, V.: Observation of turbulence profiles with lidar synergy, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-439, https://doi.org/10.5194/ems2022-439, 2022.

The overall objective of the Land surface Interactions with the Atmosphere over the Iberian Semi-arid Environment (LIAISE) project is to improve the understanding of land-atmosphere and hydrology interactions in a semi-arid region characterized by strong surface heterogeneity owing to contrasts between the natural landscape and intensive, irrigated agriculture. It is known that irrigation can potentially impact the local atmospheric boundary layer (ABL) characteristics, thereby modifying near surface atmospheric conditions within and downwind of irrigated areas (e.g., Lawston et al., 2020) and potentially the recycling of precipitation. The understanding of the impact of anthropization and its representation in models have been inhibited due to a lack of consistent and extensive observations. In recent years, land surface and atmospheric observation capabilities have advanced while irrigated surfaces have been increasing, leading to a renewed need for dedicated field campaigns over contrasting (climate) regions.

We present a summary of the LIAISE field campaign intensive phase between July 15–29 2021, which took place over the Catalan counties of Urgell and Pla d'Urgell within the Ebro basin in north-eastern Spain. LIAISE is located in a semi-arid hot, dry Mediterranean climate, with a very sharp delineation between a vast, nearly continuous intensively-irrigated region and the generally much more dry rain-fed zone to the east of the study domain. Intensive, spatially distributed surface-based and airborne measurements of the atmospheric boundary layer were made, along with intensive eco-physiological observations and remotely-sensed high spatial resolution mesoscale measures of surface variables from aircraft and unmanned aerial vehicles (UAVs). Two energy budget sites were extended with a network of soil moisture sensors since they were used to evaluate remote sensing data from aircraft. More than 30 institutions took part in the campaign covering a wide range of expertise and spatiotemporal scales in the methods involved, be it through modelling or measurements.

In this contribution we will elaborate on the spatial and temporal scales involved in the processes of evapotranspiration. We will make a strong case for integrated approaches combining observation and modelling techniques to further develop our understanding of evapotranspiration. This will be illustrated with a case study using a mixed layer column model heavily guided and constrained by measurements. 

How to cite: Hartogensis, O., Boone, A., Mangan, M.-R., Bellvert, J., Best, M., Brooke, J., Canut-Rocafot, G., Cuxart, J., Le Moigne, P., Miro, J. R., Polcher, J., Price, J., and Quintana Segui, P.: LIAISE campaign: Measuring and Modelling Evapotranspiration over Irrigated Terrain in a Semi-Arid Environment, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-616, https://doi.org/10.5194/ems2022-616, 2022.

The variability of vertical profiles of the normalized vertical velocity variance was examined to characterize turbulence and to investigate its dependence on meteorological parameters in the convective boundary layer. The vertical profiles of the vertical velocity variance were calculated using the Doppler lidar dataset from the FESSTVaL measurement campaign collected during two consecutive summer periods. The measurements took place around the Lindenberg meteorological observatory (MOL-RAO), near Berlin, Germany, representative of a flat-terrain covered with crops and patches of forest. The variability of a daily average of the normalized variance was analyzed during a period of a well-developed boundary layer. We classified the dataset into three main categories based on the presence of clouds and extracting only the periods without precipitation: clear-sky, cloud-topped, and rainy days. The mean profile of the normalized variance of the vertical velocity systematically increases from the rainy, cloud-topped to clear-sky days categories. The magnitude of the mean profile during the clear-sky and cloud-topped days is similar to the reference profile of Lenschow et al. (1980), although the variability among the days is large. The dependence of this variability of the normalized variance on the meteorological parameters was examined. We found that the relative humidity, Bowen ratio, surface latent heat flux, and cloud fraction relate to the variability of the normalized variance. A closer look at the cloud fraction during the cloud-topped days shows an increment of the normalized variance with a decrease of humidity in the boundary layer similar to the increment from rainy to cloudy and clear-sky days.

How to cite: Dewani, N., Sakradzija, M., Schmidli, J., and Schlemmer, L.: Vertical velocity variance and its dependency on meteorological parameters in the convective boundary layer, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-581, https://doi.org/10.5194/ems2022-581, 2022.

Cosmic-ray neutron albedo sensing (CRNS) is a modern technology that can be used to continuously measure the average water content in the environment (i.e., in soil, snow, or vegetation). The sensor footprint encompasses an area of 10-15 hectares and extends to 20-50 decimeters deep into the soil. This method might be an alternative to conventional in-situ sensors or to expensive sampling of soil or snow. It also has the potential to bridge the scale gap between point-scale measurements and remote-sensing data in both, the horizontal and the vertical domain.

Currently, more than 200 sensors are operated in the growing networks of national and continental observatories. CRNS stations are continuously monitoring the local water dynamics at various field sites worldwide. They require almost no maintenance over the years due to a solar module, battery and telemetry. Since the method works non-invasively, the soil is left undisturbed. The passive sensing technique measures natural cosmogenic background radiation which interacts with hydrogen in the ground independent of temperature, frost, or wind effects. CRNS can also be used on mobile platforms for on-demand soil moisture mapping at the field- or regional scale. The sensors are rapidly operational on any ground- or airborne vehicle.

In this presentation we will show various examples of stationary CRNS and their performance compared to traditional sensors at various sites in Germany, Europe, and beyond. We will discuss applications for hydrological modeling and new spatial mapping approaches. The data is particularly useful to study hydrological extreme events, droughts, heatwaves, floods, snow melt/accumulation, and it can be applied as a lower boundary condition in atmospheric models, in hydrological models, or agricultural irrigation management.

How to cite: Schrön, M., Zacharias, S., Beyrich, F., Böttcher, F., Boeing, F., Marx, A., Fatima, E., Kumar, R., Kaluza, M., Samaniego, L., Attinger, S., and Dietrich, P.: Autonomous Monitoring of Soil Moisture & Snow Water Equivalent with Stationary and Mobile Cosmic-Ray Neutron Sensors, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-577, https://doi.org/10.5194/ems2022-577, 2022.

The Multipurpose Airborne Sensor Carrier (MASC) is a fixed-wing unmanned aircraft system (UAS) that has been continuously developed and used for in-situ, high-resolution flight measurements of atmospheric variables such as wind, temperature, humidity as well as trace gas and particle concentrations by the Environmental Physics group at University of Tübingen. The most recent innovation in the MASC-series is the MASC-V type vertical takeoff and landing UAS. It has been designed in cooperation with ElevonX d.o.o.. Compared to its predecessor, MASC-3, it can automatically takeoff and land on small patches of land while carrying an identical atmospheric measurement payload. This capability, complemented by an enhanced safety and operational concept, allows for deployment in offshore applications. Particularily, MASC-V has demonstrated safe operation beyond visual line of sight (BVLOS) from the remote safety pilot in offshore applications within the EUs new legal framework introduced in 2020.

Before its first offshore mission, MASC-V underwent a system validation against a meteorological tower at the German Weather Service (DWD) Observatory site at Falkenberg, Germany. Offshore measurements were conducted from the German offshore island Heligoland at the Testfield for Maritime Technologies in cooperation with the Fraunhofer Institute for Applied Material Science in September 2021. The goal of the Heligoland campaign was to validate the remote sensing of sea surface wind measurements by Synthetic Aperture Radar (SAR) satellites of the Sentinel-1 formation at low flight altitudes (20 m - 30 m). SAR satellites can deliver detailed wind data over large areas such as the German Bight including for example wind farm wake effects. Direct validation of these results is difficult with other in-situ techniques. Buoys and measurement towers or platforms can provide stationary data. Aerial measurements with manned aircraft are only possible at higher altitudes. The new UAS data provide the first aerial in-situ SAR validation measurement at low altitude. Additionally, we have demonstrated the capabilities of VTOL fixed-wing UAS for vertical profiling as well as to operate tens of kilometers away from ground personell over open water.

How to cite: Weber, I., Platis, A., zum Berge, K., Schön, M., Boventer, J., Bamati, M., Savvakis, V., Miranda Garcia, G., Sajidi, M., Wang, Y., and Bange, J.: The Unmanned Multipurpose Airborne Sensor Carrier MASC-V for Offshore Wind Energy Research, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-371, https://doi.org/10.5194/ems2022-371, 2022.

Doppler wind lidar systems are an indispensable tool for the observation of the atmospheric boundary layer. With varying atmospheric conditions in the boundary layer the performance and availability of these systems varies. In order to ensure their quality measurements are needed to validate the lidar measurements.

During the FESSTVaL field measurement campaign in summer 2021 airborne meteorological measurements in the atmospheric boundary layer above the measuring field Falkenberg of the German Weather Service measurements were recorded for this purpose.

The focus was on the validation of Doppler lidar measurements of the wind speed, wind direction and turbulence kinetic energy in the altitude range from 90 m to 600 m above ground. The obtained data will be used to show in how far the lidar data quality is depending on the altitude the measurements have been taken from.

The validation data were collected with an unmanned aerial system (UAS) of type MASC-3 (Multipurpose Airborne SensorCarrier 3) operated by the University of tuebingen.

The UAS MASC-3 is used for in-situ meteorological measurements of turbulent variables (three-dimensional wind vector, temperature, humidity and turbulence) as well as aerosol particles in the lower atmosphere. [1]

With the help of our UAS measurements, the quality, spatial resolution, and significance of lidar data is investigated and will be assessed in different measurement configurations and under different atmospheric conditions, such as thermal stratification, water vapor content, concentration of aerosol particles and aerosol particle size distribution.

Suitable scanning strategies for the lidar systems can thus be determined, characterized, and the measurement error as well as the representativeness and availability of the lidar wind and turbulence data will be quantified.

The result of the assessment will help to determine the initially mentioned performance and availability of lidar more accurately, as well as to better integrate remote sensing instrumentation into an operational measurement network.

[1] A. Rautenberg et al., MDPI Sensors doi:10.3390/s19102292 (2019)

How to cite: Boventer, J., Weber, I., Schön, M., zum Berge, K., Platis, A., Bange, J., Beyrich, F., Detring, C., and Päschke, E.: Validation of Doppler wind LiDARs of the German Weather Service (DWD) using small unmanned aerial systems ( UAS ), EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-237, https://doi.org/10.5194/ems2022-237, 2022.

Ground-based microwave radiometers (MWRs) which operate within the K-band and V-band (22 – 32 GHz and 51 – 58 GHz) are used to obtain temperature profiles (T) and rather coarse humidity profiles (H) of the troposphere. MWRs measure microwave radiances, expressed as brightness temperatures (TB), in zenith and other angles over an area of ~10 km radius. The brightness temperatures can be used to retrieve the T-profiles and H-profiles. Ground-based MWRs are also among the best instruments to measure path integrated values like IWV (Integrated Water Vapor) and LWP (Liquid Water Path), with excellent uncertainties below 0.5 kg/m² and 20 g/m², respectively. Besides zenith observations which provide these variables with a high temporal resolution (up to 1 second), elevation scans are used to retrieve more precise temperature profiles close to the ground, as well as to assess horizontal water vapor and cloud inhomogeneities.

Driven by the E-PROFILE program, a business case proposal was accepted by EUMETNET last year to continuously provide MWR data to the European meteorological services for boundary layer monitoring and assimilation to numerical weather prediction (NWP) models. Also, the European Research Infrastructure for the observation of Aerosol, Clouds, and Trace gases ACTRIS and the European COST action PROBE (PROfiling the atmospheric Boundary layer at European scale) currently focus on establishing continent-wide quality and observation standards for MWR networks for research as well as for NWP applications.

When installing a MWR, it has to be kept in mind that external error sources like physical obstacles and radio frequency interference (RFI) can have an impact on observations and the quality of the obtained atmospheric profiles when they are within the range of the MWR. Therefore, identifying and coping with these kinds of errors is one important part of the quality control, especially while searching for a suitable measurement location with low disturbances. If physical obstacles like trees, towers, masts and walls are too close to the MWR they can have significant repercussions in elevation scans which are necessary for deriving accurate T-profiles. That is why it is crucial to pinpoint the exact location of these obstacles and to determine a minimum distance at which they do not interfere with the MWR anymore. We will present a sensitivity study which uses a line-by-line (LBL) radiative transfer (RT) model and in which obstacles at any distance from the profiler can be simulated. Output comparisons with and without these simulated obstacles provide a theoretical atmospheric penetration depth per frequency channel and elevation.

How to cite: Böck, T., Pospichal, B., and Löhnert, U.: Characterizing the influence of obstacles on scanning microwave profilers, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-682, https://doi.org/10.5194/ems2022-682, 2022.

The size, shape and ground-impact location of each hailstone is characterised by its trajectory through the parent hailstorm. This trajectory determines whether the hailstone passes through regions of the storm that are more favorable for growth or even miss out entirely. Recent simulation-based studies have demonstrated the diversity of trajectories and how certain pathways exist in response to storm processes. Hail trajectories can also be simulated from radar observations, and this has been shown to significantly improve the accuracy of the estimated ground hail swath for case studies. Operational hail analysis techniques currently do not consider trajectories, leaving a degree of uncertainty when estimating ground impact. The lack of robust observational datasets to verify trajectories is one factor that limits the transition of this new science into operations.

This talk will introduce an innovative approach to measuring trajectories within a hailstorm using hailstone-shaped probes called “HailSondes”. Improvements in low-energy radio, energy storage and electronics miniaturization are combined to make this new sensor possible, which, until recently, was the realm of fantasy for meteorologists. HailSonde measurements will provide critical validation for the practical application radar-derived trajectories for hailstorm analysis and nowcasting, supporting the transition to future hail services and benefiting a wide range of sectors from aviation, risk management, transport and public safety. The design challenges, simulations, prototype development and deployment of HailSondes within field experiments are discussed.

How to cite: Soderholm, J., Kumjian, M., Peterson, A., Brook, J., and Protat, A.: Measuring Hailstone Trajectories with the HailSonde, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-511, https://doi.org/10.5194/ems2022-511, 2022.

Continuous water vapor profiling within the atmospheric boundary layer is a major unmet measurement requirement for real-time monitoring of humidity profiles and improving numerical weather prediction. Water vapor mixing ratio profile information can be used in mesoscale numerical models for severe weather prediction, flash flood prediction, energy management, and other applications. Vaisala has been developing broadband Water Vapor Differential Absorption Lidar (DIAL) to meet with the need of lacking humidity profile observations. Vaisala broadband DIAL not only reports water vapor mixing ratio in the boundary layer, but also serves as an atmospheric profiler offering attenuated backscatter profile to obtain information on scatterers in the atmosphere including clouds, precipitation, and aerosols.

In this presentation, the latest hardware and software improvements on our broadband DIAL are presented with case examples. In recent years, we have been continuously testing our prototypes with different scientific partners in different climates as well as on our test field. Based on the vital feedback from our scientific partners we have been able to focus and develop solutions to improve the prototype performance incrementally. We have been developing features based on the user feedback, as well as improving data format and data visualization. Most importantly, the performance of the instrument has been improved, including the reduction of instrument-related biases in various situations. Our target is to meet the needs of the community to better serve the field of numerical weather prediction and use of broadband DIAL in networks.

In addition, we will present our vision of the finalized product that can help with meteorological applications from numerical weather prediction improvements to atmospheric boundary layer research and unattended operation in all-weather situations.

How to cite: Tuononen, M., Lehtinen, R., Tuominen, P., and Roininen, R.: Latest developments on Vaisala broadband DIAL with examples, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-559, https://doi.org/10.5194/ems2022-559, 2022.

For many applications, such as ensuring efficiency of future wind farms and characterizing wind hazards at ports, airports, or industrial plants, measuring accurate and precise wind is critical. Scanning Wind Lidars provide a solution to deliver demanding wind measurements, measuring in full hemisphere at multiple ranges around its location with multiple scanning patterns (azimuthal scans, elevation scans, etc.). Since their implementation, user feedbacks called for more flexibility in measurement modes, limitation of range ambiguities, and longer acquisition distances. For these reasons, a new version of the Windcube Scan was designed to overcome these limitations. An internal and external validation was performed over the last year to ensure acceptable behaviors and measurement performances of hardware/software components of outdoor/indoor measurements for established regulations.

The internal validation conducted within Vaisala France site near Paris consists of both an indoor and outdoor validation protocol. The indoor verification test, characterized as a patented indoor bench, aims at testing radial wind speed precision with intrinsic lidar parameters such as pulse shape, energy, etc. The outdoor validation follows guidelines set by the ISO 28902-2 as the lidar wind speed was compared to an ultrasonic anemometer on a meteorological tower 2.5km away. The instantaneous wind speed measurements from both devices are then compared for precision and accuracy with proper filtering of unsuitable weather conditions.  

External validation prompted collaboration with MeteoSwiss and DWD, both pioneers in the PROBE European project for large-scale remote-sensing deployment and data-sharing. Both organizations received the new version of WindCube Scan for a beta test. They gathered wind data at their sites and compared radial data to other remote sensing devices. All scanning patterns (PPI, RHI, DBS, VAD, fixed) were tested to verify the performances of different resolutions, data retrieval, and wind speed precision.

The results of this validation thus far show positive performance and noticeable improvements of the new version of the Windcube Scan. Additionally, the external validation collaboration with other PROBE members highlights the importance of fortifying and understanding remote sensing device precision and data collection methods for large-scale observational network integration.

How to cite: Benzo, C. and Thobois, L.: Validation of the New Version of the WindCube Scan Lidar, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-633, https://doi.org/10.5194/ems2022-633, 2022.

Most of the world’s population now lives in urban areas that have different urban climates and environmental characteristics with elevated temperatures, frequent heat stress, and air pollution due to urbanization and climate change. These processes affect the daily lives of citizens worldwide, however, detailed spatial and temporal meteorological and environmental data in cities are often lacking. In order to address this problem, the Novi Sad Urban Climate Research Team (NSUCRT) has developed a Mobile Micrometeorological Carts (MMCs) to enable detailed spatial and temporal measurements in urban and non-urban areas. MMCs consist of sensors that measure air temperature, relative humidity, wind speed and direction, globe temperature, global radiation, and six-directional short- and long-wave radiation. The measurement time resolution is two minutes. In addition, a desktop application was created for the transfer of data from MMCs to a computer. This type of detailed and precise equipment will enable researchers and practitioners to obtain micrometeorological data in diverse urban (and non-urban) areas, such as urban squares, streets, parks, river quays, forests, etc. Based on the obtained micrometeorological data, hot and cool spots in the city can be identified, which can be used for the development of climate-friendly planning and design guidelines tackling heat-health issues in cities. In addition, the obtained micrometeorological data can be used for the calculation of mean radiant temperature and outdoor thermal comfort indices, which are important for assessing the comfort and health of citizens in diverse urban environments. Finally, MMCs measurements can be applied for the validation of microclimate models, such as ENVI-met, PALM-4U, SOLWEIG, and RayMan.

Acknowledgment: The research was supported by a project (number 142-451-2557/2021-01) financed by the Autonomous Province of Vojvodina (regional government).

How to cite: Milošević, D., Savić, S., Šećerov, I., and Dunjić, J.: Introducing Mobile Micrometeorological Carts (MMCs) for urban and non-urban micrometeorological measurements, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-59, https://doi.org/10.5194/ems2022-59, 2022.