Atmospheric Measurement Techniques最新文献

{"title":"Cloud top heights and aerosol layer properties from EarthCARE lidar observations: the A-CTH and A-ALD products","authors":"U. Wandinger, M. Haarig, H. Baars, D. Donovan, Gerd-Jan van Zadelhoff","doi":"10.5194/amt-16-4031-2023","DOIUrl":"https://doi.org/10.5194/amt-16-4031-2023","url":null,"abstract":"Abstract. The high-spectral-resolution Atmospheric Lidar (ATLID) on the Earth Cloud, Aerosol and Radiation Explorer (EarthCARE)\u0000provides vertically resolved information on aerosols and clouds with unprecedented accuracy. Together with the Cloud Profiling Radar (CPR), the Multi-Spectral Imager (MSI), and the Broad-Band Radiometer (BBR) on the same platform, it allows for a new synergistic view on atmospheric processes related to the interaction of aerosols, clouds, precipitation, and radiation at the global scale.\u0000This paper describes the algorithms for the determination of cloud top height and aerosol layer information from ATLID Level 1b (L1b) and Level 2a (L2a) input data. The ATLID L2a Cloud Top Height (A-CTH) and Aerosol Layer Descriptor (A-ALD) products are developed to ensure the provision of atmospheric layer products in continuation of the heritage from the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Moreover, the products serve as input for synergistic algorithms that make use of data from ATLID and MSI. Therefore, the products are provided on the EarthCARE joint standard grid (JSG).\u0000A wavelet covariance transform (WCT) method with flexible thresholds is applied to determine layer boundaries from the ATLID Mie co-polar signal.\u0000Strong features detected with a horizontal resolution of 1 JSG pixel (approximately 1 km) or 11 JSG pixels are classified as thick or thin clouds, respectively. The top height of the uppermost cloud layer together with information on cloud layering are stored in the A-CTH product for further use in the generation of the ATLID-MSI Cloud Top Height (AM-CTH) synergy product. Aerosol layers are detected as weaker features at a resolution of 11 JSG pixels. Layer-mean optical properties are calculated from the ATLID L2a Extinction, Backscatter and Depolarization (A-EBD) product and stored in the A-ALD product, which also contains the aerosol optical thickness (AOT) of each layer, the stratospheric AOT, and the AOT of the entire atmospheric column. The latter parameter is used to produce the synergistic ATLID-MSI Aerosol Column Descriptor (AM-ACD) later in the processing chain. Several quality criteria are applied in the generation of A-CTH and A-ALD, and respective information is stored in the products. The functionality and performance of the algorithms are demonstrated by applying them to common EarthCARE test scenes. Conclusions are drawn for the application to real-world data and the validation of the products after the launch of EarthCARE.\u0000","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44671270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An extraction method for nitrogen isotope measurement of ammonium in a low-concentration environment","authors":"Alexis Lamothe, J. Savarino, P. Ginot, Lison Soussaintjean, E. Gautier, P. Akers, N. Caillon, J. Erbland","doi":"10.5194/amt-16-4015-2023","DOIUrl":"https://doi.org/10.5194/amt-16-4015-2023","url":null,"abstract":"Abstract. Ammonia (NH3) participates in the nucleation and growth\u0000of aerosols and thus plays a major role in atmospheric transparency,\u0000pollution, health, and climate-related issues. Understanding its emission\u0000sources through nitrogen stable isotopes is therefore a major focus of\u0000current work to mitigate the adverse effects of aerosol formation. Since ice\u0000cores can preserve the past chemical composition of the atmosphere for\u0000centuries, they are a top tool of choice for understanding past NH3\u0000emissions through ammonium (NH4+), the form of NH3 archived\u0000in ice. However, the remote or high-altitude sites where glaciers and ice\u0000sheets are typically localized have relatively low fluxes of atmospheric\u0000NH4+ deposition, which makes ice core samples very sensitive to\u0000laboratory NH3 contamination. As a result, accurate techniques for\u0000identifying and tracking NH3 emissions through concentration and\u0000isotopic measurements are highly sought to constrain uncertainties in\u0000NH3 emission inventories and atmospheric reactivity unknowns. Here, we\u0000describe a solid-phase extraction method for NH4+ samples of low\u0000concentration that limits external contamination and produces precise\u0000isotopic results. By limiting NH3atm exposure with a scavenging fume\u0000hood and concentrating the targeted NH4+ through ion exchange\u0000resin, we successfully achieve isotopic analysis of 50 nmol NH4+\u0000samples with a 0.6 ‰ standard deviation. This extraction\u0000method is applied to an alpine glacier ice core from Col du Dôme,\u0000Mont Blanc, where we successfully demonstrate the analytical approach\u0000through the analysis of two replicate 8 m water equivalent ice cores\u0000representing 4 years of accumulation with a reproducibility of ±2.1 ‰. Applying this methodology to other ice cores in\u0000alpine and polar environments will open new opportunities for understanding\u0000past changes in NH3 emissions and atmospheric chemistry.\u0000","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46122880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of electromagnetic interference on the evaluation of lidar-derived aerosol properties from Ny-Ålesund, Svalbard","authors":"Tim Poguntke, Christoph Ritter","doi":"10.5194/amt-16-4009-2023","DOIUrl":"https://doi.org/10.5194/amt-16-4009-2023","url":null,"abstract":"Abstract. Possible interference sources for our aerosol lidar setup with transient recorders have been assessed. This was done by two methods: a spectrum\u0000analysis of the lidar signals in order to detect radio-frequency interference and measurements of the electromagnetic interference caused by the\u0000laser power supply. We found disturbances in the analog channels of the transient recorders, presumably caused by aging effects of our older\u0000recorders. An easy method on how the signal-to-noise ratio can be improved retrospectively is presented. We also show that the usage of two-way\u0000radio at our location leads to a noticeable radio-frequency interference in the lidar profiles. Further, we present measurements of the\u0000electromagnetic interference caused by the laser power supply, which may lead to disturbances in the lidar profiles if the transient recorders are\u0000placed next to it.\u0000","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41410420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A retrieval of xCO2 from ground-based mid-infrared NDACC solar absorption spectra and comparison to TCCON","authors":"Rafaella Chiarella, M. Buschmann, J. Laughner, I. Morino, J. Notholt, C. Petri, G. Toon, V. Velazco, T. Warneke","doi":"10.5194/amt-16-3987-2023","DOIUrl":"https://doi.org/10.5194/amt-16-3987-2023","url":null,"abstract":"Abstract. Two global networks of ground-based Fourier transform spectrometers are measuring abundances of atmospheric trace gases that absorb in the near infrared and mid-infrared: the Network for the Detection of Atmospheric Composition Change (NDACC) and the Total Carbon Column Observing Network (TCCON). The first lacks a CO2 product; therefore, this study focuses on developing an xCO2 retrieval method for NDACC from a spectral window in the 4800 cm−1 region. This retrieval will allow extending ground-based measurements back in time, which we will demonstrate with historical data available from Ny-Ålesund, Svalbard. At this site, both TCCON and NDACC measurements are routinely performed, which is an advantage for collocated comparisons. The results are compared with collocated TCCON measurements of column-averaged dry-air mole fractions of CO2 (denoted by xCO2) in Ny-Ålesund, Svalbard, and only TCCON in Burgos, Philippines. We found that it is possible to retrieve xCO2 from NDACC spectra with a precision of 0.2 %. The comparison between the new retrieval and TCCON showed that the sensitivity of the new retrieval is high in the troposphere and lower in the upper stratosphere, similar to TCCON, as seen in the averaging kernels, and that the seasonality is well captured as seen in the retrieved time series. Additionally, we have included a retrieval strategy suggestion to improve the quality of the xCO2 product.\u0000","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41556218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mapping the performance of a versatile water-based condensation particle counter (vWCPC) with numerical simulation and experimental study","authors":"Weixing Hao, Fan Mei, Susanne Hering, Steven Spielman, Beat Schmid, Jason Tomlinson, Yang Wang","doi":"10.5194/amt-16-3973-2023","DOIUrl":"https://doi.org/10.5194/amt-16-3973-2023","url":null,"abstract":"Abstract. Accurate airborne aerosol instrumentation is required to determine the\u0000spatial distribution of ambient aerosol particles, particularly when dealing\u0000with the complex vertical profiles and horizontal variations of atmospheric\u0000aerosols. A versatile water-based condensation particle counter (vWCPC) has\u0000been developed to provide aerosol concentration measurements under various\u0000environments with the advantage of reducing the health and safety concerns\u0000associated with using butanol or other chemicals as the working fluid.\u0000However, the airborne deployment of vWCPCs is relatively limited due to the\u0000lack of characterization of vWCPC performance at reduced pressures. Given\u0000the complex combinations of operating parameters in vWCPCs, modeling studies\u0000have advantages in mapping vWCPC performance. In this work, we thoroughly investigated the performance of a laminar-flow\u0000vWCPC using COMSOL Multiphysics® simulation coupled with\u0000MATLAB™. We compared it against a modified vWCPC (vWCPC model 3789, TSI,\u0000Shoreview, MN, USA). Our simulation determined the performance of particle\u0000activation and droplet growth in the vWCPC growth tube, including the\u0000supersaturation, Dp,kel,0 (smallest size of particle that can\u0000be activated), Dp,kel,50 (particle size activated with 50 %\u0000efficiency) profile, and final growth particle size Dd under\u0000wide operating temperatures, inlet pressures P (30–101 kPa), and growth\u0000tube geometry (diameter D and initiator length Lini). The\u0000effect of inlet pressure and conditioner temperature on vWCPC 3789\u0000performance was also examined and compared with laboratory experiments. The\u0000COMSOL simulation result showed that increasing the temperature difference\u0000(ΔT) between conditioner temperature Tcon and\u0000initiator Tini will reduce Dp,kel,0 and the\u0000cut-off size Dp,kel,50 of the vWCPC. In addition, lowering\u0000the temperature midpoint\u0000(Tmid=Tcon+Tini2) increases\u0000the supersaturation and slightly decreases the Dp,kel. The\u0000droplet size at the end of the growth tube is not significantly dependent on\u0000raising or lowering the temperature midpoint but significantly decreases at\u0000reduced inlet pressure, which indirectly alters the vWCPC empirical cut-off\u0000size. Our study shows that the current simulated growth tube geometry (D=6.3 mm and Lini=30 mm) is an optimized choice for\u0000current vWCPC flow and temperature settings. The current simulation can more\u0000realistically represent the Dp,kel for 7 nm vWCPC and also\u0000achieved good agreement with the 2 nm setting. Using the new simulation\u0000approach, we provide an optimized operation setting for the 7 nm setting.\u0000This study will guide further vWCPC performance optimization for\u0000applications requiring precise particle detection and atmospheric aerosol\u0000monitoring.\u0000","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45196411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First-time comparison between NO2 vertical columns from Geostationary Environmental Monitoring Spectrometer (GEMS) and Pandora measurements","authors":"Serin Kim, Daewon Kim, H. Hong, L. Chang, Hanlim Lee, Deok-Rae Kim, Donghee Kim, Jeong-Ah Yu, Dong-Won Lee, U. Jeong, C. Song, Sang-Woo Kim, Sang-Seo Park, Jhoon Kim, T. Hanisco, Junsung Park, W. Choi, Kwangyul Lee","doi":"10.5194/amt-16-3959-2023","DOIUrl":"https://doi.org/10.5194/amt-16-3959-2023","url":null,"abstract":"Abstract. The Geostationary Environmental Monitoring Spectrometer (GEMS) is a UV-visible (UV-Vis) spectrometer on board the GEO-KOMPSAT-2B (Geostationary Korea Multi-Purpose Satellite 2B) satellite launched into a geostationary orbit in February 2020. To evaluate the GEMS NO2 total column data, a comparison was carried out using the NO2 vertical column density (VCD) that measured direct sunlight using the Pandora spectrometer system at four sites in Seosan, South Korea, from November 2020 to January 2021. Correlation coefficients between GEMS and Pandora NO2 data at four sites ranged from 0.35 to 0.48, with root mean square errors (RMSEs) from 4.7×1015 to 5.5×1015 molec. cm−2 for a cloud fraction (CF) <0.7. Higher correlation coefficients of 0.62–0.78 with lower RMSEs from 3.3×1015 to 5.0×1015 molec. cm−2 were found with CF <0.3, indicating the higher sensitivity of GEMS to atmospheric NO2 in less cloudy conditions. Overall, the GEMS NO2 total column data tended to be lower than the Pandora data, owing to differences in the representative spatial coverage, with a large negative bias under high CF conditions. With a correction for horizontal representativeness in the Pandora measurement coverage, correlation coefficients ranging from 0.69 to 0.81, with RMSEs from 3.2×1015 to 4.9×1015 molec. cm−2, were achieved for CF <0.3, showing a better correlation with the correction than without the correction.\u0000","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46483171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retrieving 3D distributions of atmospheric particles using Atmospheric Tomography with 3D Radiative Transfer – Part 2: Local optimization","authors":"J. Loveridge, Aviad Levis, L. Di Girolamo, Vadim Holodovsky, Linda Forster, A. Davis, Y. Schechner","doi":"10.5194/amt-16-3931-2023","DOIUrl":"https://doi.org/10.5194/amt-16-3931-2023","url":null,"abstract":"Abstract. Our global understanding of clouds and aerosols relies on the remote sensing of their optical, microphysical, and macrophysical properties using, in part, scattered solar radiation. Current retrievals assume clouds and aerosols form plane-parallel, homogeneous layers and utilize 1D radiative transfer (RT) models. These assumptions limit the detail that can be retrieved about the 3D variability in the cloud and aerosol fields and induce biases in the retrieved properties for highly heterogeneous structures such as cumulus clouds and smoke plumes. In Part 1 of this two-part study, we validated a tomographic method that utilizes multi-angle passive imagery to retrieve 3D distributions of species using 3D RT to overcome these issues. That validation characterized the uncertainty in the approximate Jacobian used in the tomographic retrieval over a wide range of atmospheric and surface conditions for several horizontal boundary conditions. Here, in Part 2, we test the algorithm's effectiveness on synthetic data to test whether the retrieval accuracy is limited by the use of the approximate Jacobian. We retrieve 3D distributions of a volume extinction coefficient (σ3D) at 40 m resolution from synthetic multi-angle, mono-spectral imagery at 35 m resolution derived from stochastically generated cumuliform-type clouds in (1 km)3 domains. The retrievals are idealized in that we neglect forward-modelling and instrumental errors, with the exception of radiometric noise; thus, reported retrieval errors are the lower bounds. σ3D is retrieved with, on average, a relative root mean square error (RRMSE) &lt; 20 % and bias &lt; 0.1 % for clouds with maximum optical depth (MOD) &lt; 17, and the RRMSE of the radiances is &lt; 0.5 %, indicating very high accuracy in shallow cumulus conditions. As the MOD of the clouds increases to 80, the RRMSE and biases in σ3D worsen to 60 % and −35 %, respectively, and the RRMSE of the radiances reaches 16 %, indicating incomplete convergence. This is expected from the increasing ill-conditioning of the inverse problem with the decreasing mean free path predicted by RT theory and discussed in detail in Part 1. We tested retrievals that use a forward model that is not only less ill-conditioned (in terms of condition number) but also less accurate, due to more aggressive delta-M scaling. This reduces the radiance RRMSE to 9 % and the bias in σ3D to −8 % in clouds with MOD ∼ 80, with no improvement in the RRMSE of σ3D. This illustrates a significant sensitivity of the retrieval to the numerical configuration of the RT model which, at\u0000least in our circumstances, improves the retrieval accuracy. All of these\u0000ensemble-averaged results are robust in response to the inclusion of radiometric noise during the retrieval. However, individual realizations can have large deviations of up to 18 % in the mean extinction in clouds with MOD ∼ 80, which indicates large uncertainties in the retrievals in the optically thick limit. Using less ill-conditi","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47063086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of Aeolus winds on near-surface wind forecasts over tropical ocean and high-latitude regions","authors":"Haichen Zuo, C. Hasager","doi":"10.5194/amt-16-3901-2023","DOIUrl":"https://doi.org/10.5194/amt-16-3901-2023","url":null,"abstract":"Abstract. To detect global wind profiles and improve numerical weather prediction (NWP), the European Space Agency (ESA) launched the Aeolus satellite carrying a spaceborne Doppler wind lidar in 2018. After the successful launch, the European Centre for Medium-Range Weather Forecasts (ECMWF) performed the observing system experiments (OSEs) to evaluate the contribution of Aeolus data to NWP. This study aims to assess the impact of Aeolus wind assimilation in the ECMWF model on near-surface (10 m height) wind forecasts over tropical ocean regions by taking buoy measurements for reference and over high-latitude regions by taking weather station data for reference for the year 2020. The assessments were conducted mainly through inter-comparison analysis. The results show that Aeolus data assimilation has a limited impact on sea surface wind forecasts for tropical regions when compared with buoy measurements. For the high-latitude regions in the Northern Hemisphere, Aeolus is able to improve near-surface wind forecasts. This positive impact is more evident as the forecast time step is extended, during the first half year of 2020 and during the winter months. In addition, the v component tends to benefit more from the Aeolus observations than the u component. For the Southern Hemisphere, a few error reductions are observed but exist randomly. Overall, this in situ data-based assessment expands our understanding of the role of Aeolus data assimilation with the global NWP model in predicting near-surface wind for tropical oceans and high-latitude regions.\u0000","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41528688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retrieval of snow layer and melt pond properties on Arctic sea ice from airborne imaging spectrometer observations","authors":"Sophie Rosenburg, Charlotte Lange, E. Jäkel, M. Schäfer, A. Ehrlich, M. Wendisch","doi":"10.5194/amt-16-3915-2023","DOIUrl":"https://doi.org/10.5194/amt-16-3915-2023","url":null,"abstract":"Abstract. A melting snow layer on Arctic sea ice, as a composition of ice, liquid water, and air, supplies meltwater that may trigger the formation of melt ponds. As a result, surface reflection properties are altered during the melting season and thereby may change the surface energy budget. To study these processes, sea ice surface\u0000reflection properties were derived from airborne measurements using imaging spectrometers. The data were collected over the closed and marginal Arctic sea ice zone north of Svalbard in May–June 2017. A retrieval approach based\u0000on different absorption indices of pure ice and liquid water in the near-infrared spectral range was applied to the campaign data. The technique enabled us to retrieve the spatial distribution of the liquid water\u0000fraction of a snow layer and the effective radius of snow grains. For observations from three research flights, liquid water fractions between 6.5 % and 17.3 % and snow grain sizes between 129 and 414 µm were derived. In addition, the melt pond depth was\u0000retrieved based on an existing approach that isolates the dependence of a melt pond reflection spectrum on the pond depth by eliminating the reflection contribution of the pond ice bottom. The application of the approach to several case studies revealed a high variability of melt pond depth, with maximum depths of 0.33 m.\u0000The results were discussed considering uncertainties arising from the airborne reflection measurements, the setup of radiative transfer simulations, and the retrieval method itself.\u0000Overall, the presented retrieval methods show the potential and the limitations of airborne measurements with imaging spectrometers to map the transition phase of the Arctic sea ice surface, examining the snow layer\u0000composition and melt pond depth.\u0000","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48255486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of error components in rainfall retrieval from collocated commercial microwave links","authors":"Anna Spackova, M. Fencl, V. Bareš","doi":"10.5194/amt-16-3865-2023","DOIUrl":"https://doi.org/10.5194/amt-16-3865-2023","url":null,"abstract":"Abstract. Opportunistic rainfall sensing using commercial microwave links (CMLs) operating in telecommunication networks has the potential to complement conventional rainfall monitoring; however, the diversity of sensors and their errors are difficult to handle. This analysis empirically evaluates errors in CML observations that manifest discrepancies between collocated sensors without reference to rainfall measurements. Collocated CMLs are evaluated as independent rainfall sensors and enable us to assess the effect of hardware homogeneity and measurement consistency using CML observations at 12 sites within a real telecommunication network in Prague. The evaluation considers 33 rainfall events distinguishing between stratiform and convective rainfall types in the period of 2014–2016, monitored at 1 min temporal resolution. Collocated CMLs of identical and different frequencies are evaluated, and different rainfall types are discussed. The collocated CMLs are in excellent agreement. The inherent error in rain-induced attenuation for paired independent CMLs is 0.4 dB. The high correlation of the rainfall intensity measurements between the collocated sensors was obtained in a range of 0.96 to 0.99, and the root mean square error ranges from 0.4 to 1.7 mm h−1. This confirms the homogeneous behaviour of the hardware in a real network. Therefore, the data of CMLs of the same characteristics can be processed with identical parameters for rainfall retrieval models.\u0000","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43415514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}