Author(s):
Loew, Alexander; Bell, William; Brocca, Luca; Bulgin, Claire E.; Burdanowitz, Jörg; Calbet, Xavier; Donner, Reik V.; Ghent, Darren; Gruber, Alexander; Kaminski, Thomas; Kinzel, Julian; Klepp, Christian; Lambert, Jean-Christopher; Schaepman-Strub, Gabriela; Schröder, Marc; Verhoelst, Tijl
Publication title: Reviews of Geophysics
2017
| Volume: 55 | Issue: 3
2017
Abstract:
Assessing the inherent uncertainties in satellite data products is a challenging task. Different technical approaches have been developed in the Earth… Assessing the inherent uncertainties in satellite data products is a challenging task. Different technical approaches have been developed in the Earth Observation (EO) communities to address the validation problem which results in a large variety of methods as well as terminology. This paper reviews state-of-the-art methods of satellite validation and documents their similarities and differences. First, the overall validation objectives and terminologies are specified, followed by a generic mathematical formulation of the validation problem. Metrics currently used as well as more advanced EO validation approaches are introduced thereafter. An outlook on the applicability and requirements of current EO validation approaches and targets is given. more
Author(s):
Ahmad, Momina; Zeeshan, Muhammad
Publication title: Energy Conversion and Management
2022
| Volume: 256
2022
Abstract:
Accelerating the decarbonization of power sector requires strategic planning and multi-aspectual feasibility analysis of renewable energy systems incl… Accelerating the decarbonization of power sector requires strategic planning and multi-aspectual feasibility analysis of renewable energy systems including, but not limited to, meteorological, land-use, techno-economic and environmental parameters. In this study, at first, the suitability of reanalysis datasets of Direct Normal Irradiance, air temperature, wind speed, relative humidity and air pressure was investigated at different timescales and locations over Pakistan. High correlation (R > 0.9) and low bias is found for Surface Solar Radiation Data records – Heliosat East, after preprocessing, among radiation datasets in consideration. Likewise, Modern-Era Retrospective analysis for Research and Applications version 2 datasets of temperature and air pressure strongly correlate with ground measurements whereas wind speed and relative humidity show peculiarity. Afterwards, resource maps from long-term timeseries are developed for each of the aforementioned parameters. In the second part, spatial feasibility and Analytical Hierarchy Process based site suitability is assessed utilizing site-specific meteorological, socio-economic and environmental parameters. Moreover, multi-parametric evaluation of techno-economic potential is performed using bias-corrected datasets. For technical potential, System Advisor Model’s Physical Trough Collector model is used for exclusively selected points. Additionally, cost of water usage is introduced in estimation of Levelized Cost of Electricity besides other parameters. Cumulative power capacity potential of 10,035 GW is identified for country, with net cost estimated below 0.096 USD/kWh. Nine sites are found to have generation potential greater than 1200 TWh/year, the individual capacity to fulfil total predicted energy demand of the country for year 2030. Around 6.5% of viable regions are found to be highly suitable for plant deployment. Land cover and lack of access to transmission network act as limiting barriers in installation of concentrated solar power plants at many potential sites across the country. more
Author(s):
Lavergne, Thomas; Sørensen, Atle Macdonald; Kern, Stefan; Tonboe, Rasmus; Notz, Dirk; Aaboe, Signe; Bell, Louisa; Dybkjær, Gorm; Eastwood, Steinar; Gabarro, Carolina; Heygster, Georg; Killie, Mari Anne; Brandt Kreiner, Matilde; Lavelle, John; Saldo, Roberto; Sandven, Stein; Pedersen, Leif Toudal
Publication title: The Cryosphere
2019
| Volume: 13 | Issue: 1
2019
Abstract:
Abstract. We introduce the OSI-450, the SICCI-25km and the SICCI-50km climate data records of gridded global sea-ice concentration. These three record… Abstract. We introduce the OSI-450, the SICCI-25km and the SICCI-50km climate data records of gridded global sea-ice concentration. These three records are derived from passive microwave satellite data and offer three distinct advantages compared to existing records: first, all three records provide quantitative information on uncertainty and possibly applied filtering at every grid point and every time step. Second, they are based on dynamic tie points, which capture the time evolution of surface characteristics of the ice cover and accommodate potential calibration differences between satellite missions. Third, they are produced in the context of sustained services offering committed extension, documentation, traceability, and user support. The three records differ in the underlying satellite data (SMMR & SSM/I & SSMIS or AMSR-E & AMSR2), in the imaging frequency channels (37 GHz and either 6 or 19 GHz), in their horizontal resolution (25 or 50 km), and in the time period they cover. We introduce the underlying algorithms and provide an evaluation. We find that all three records compare well with independent estimates of sea-ice concentration both in regions with very high sea-ice concentration and in regions with very low sea-ice concentration. We hence trust that these records will prove helpful for a better understanding of the evolution of the Earth's sea-ice cover. more
Author(s):
Gao, Q.; Zeman, C.; Vergara-Temprado, J.; Lima, D.C.A.; Molnar, P.; Schär, C.
Publication title: Weather and Climate Dynamics
2023
| Volume: 4 | Issue: 1
2023
Abstract:
Atmospheric vortex streets are a widely studied dynamical effect of isolated mountainous islands. Observational evidence comes from case studies and s… Atmospheric vortex streets are a widely studied dynamical effect of isolated mountainous islands. Observational evidence comes from case studies and satellite imagery, but the climatology and annual cycle of vortex shedding are often poorly understood. Using the non-hydrostatic limited-area COSMO model driven by the ERA-Interim reanalysis, we conducted a 10-year-long simulation over a mesoscale domain covering the Madeira and Canary archipelagos at high spatial (grid spacing of 1 km) and temporal resolutions. Basic properties of vortex streets were analysed and validated through a 6 d long case study in the lee of Madeira Island. The simulation compares well with satellite and aerial observations and with existing literature on idealised simulations. Our results show a strong dependency of vortex shedding on local and synoptic-flow conditions, which are to a large extent governed by the location, shape and strength of the Azores high. As part of the case study, we developed a vortex identification algorithm. The algorithm is based on a set of criteria and enabled us to develop a climatology of vortex shedding from Madeira Island for the 10-year simulation period. The analysis shows a pronounced annual cycle with an increasing vortex-shedding rate from April to August and a sudden decrease in September. This cycle is consistent with mesoscale wind conditions and local inversion height patterns. © 2023 Qinggang Gao et al. more
Author(s):
Araveti, Sandeep; Quintana, Cristian Aguayo; Kairisa, Evita; Mutule, Anna; Adriazola, Juan Pablo Sepulveda; Sweeney, Conor; Carroll, Paula
Publication title: Wind
2022
| Volume: 2 | Issue: 2
2022
Abstract:
Renewable and local energy communities are viewed as a key component to the success of the energy transition. In this paper, we estimate wind power po… Renewable and local energy communities are viewed as a key component to the success of the energy transition. In this paper, we estimate wind power potential for such communities. Acquiring the most accurate weather data is important to support decision-making. We identify the most reliable publicly available wind speed data and demonstrate a case study for typical energy community scenarios such as a single commercial turbine at coastal and inland locations in Ireland. We describe our assessment methodology to evaluate the quality of the wind source data by comparing it with meteorological observations. We make recommendations on which publicly available wind data sources, such as reanalysis data sources (MERRA-2, ERA-5), PVGIS, and NEWA are best suited to support Renewable Energy Communities interested in exploring the possibilities of renewable wind energy. ERA5 is deemed to be the most suitable wind data source for these locations, while an anomaly is noted in the NEWA data. more
Author(s):
Petty, Alek A.; Keeney, Nicole; Cabaj, Alex; Kushner, Paul; Bagnardi, Marco
Publication title: Cryosphere
2023
| Volume: 17 | Issue: 1
2023
Abstract:
NASA's ICESat-2 mission has provided near-continuous, high-resolution estimates of sea ice freeboard across both hemispheres since data collection sta… NASA's ICESat-2 mission has provided near-continuous, high-resolution estimates of sea ice freeboard across both hemispheres since data collection started in October 2018. This study provides an impact assessment of upgrades to both the ICESat-2 freeboard data (ATL10) and NASA Eulerian Snow On Sea Ice Model (NESOSIM) snow loading on estimates of winter Arctic sea ice thickness. Misclassified leads were removed from the freeboard algorithm in the third release (rel003) of ATL10, which generally results in an increase in freeboards compared to rel002 data. The thickness increases due to increased freeboards in ATL10 improved comparisons of Inner Arctic Ocean sea ice thickness with thickness estimates from ESA's CryoSat-2. The upgrade from NESOSIM v1.0 to v1.1 results in only small changes in snow depth and density which have a less significant impact on thickness compared to the rel002 to rel003 ATL10 freeboard changes. The updated monthly gridded thickness data are validated against ice draft measurements obtained by upward-looking sonar moorings deployed in the Beaufort Sea, showing strong agreement (r2 of 0.87, differences of 11 ± 20 cm). The seasonal cycle in winter monthly mean Arctic sea ice thickness shows good agreement with various CryoSat-2 products (and a merged ICESat-2-CryoSat-2 product) and PIOMAS (Pan-Arctic Ice-Ocean Modeling and Assimilation System). Finally, changes in Arctic sea ice conditions over the past three winter seasons of data collection (November 2018-April 2021) are presented and discussed, including a 50 cm decline in multiyear ice thickness and negligible interannual differences in first-year ice. Interannual changes in snow depth provide a notable impact on the thickness retrievals on regional and seasonal scales. Our monthly gridded thickness analysis is provided online in a Jupyter Book format to increase transparency and user engagement with our ICESat-2 winter Arctic sea ice thickness data. © 2023 Alek A. Petty et al. more
Author(s):
Yang, Dazhi; Bright, Jamie M.
Publication title: SOLAR ENERGY
2020
| Volume: 210 | Issue: SI
2020
Abstract:
Gridded solar radiation products, namely satellite-derived irradiance and reanalysis irradiance, are key to the next-generation solar resource assessm… Gridded solar radiation products, namely satellite-derived irradiance and reanalysis irradiance, are key to the next-generation solar resource assessment and forecasting. Since their accuracies are generally lower than that of the ground-based measurements, providing validation of the gridded solar radiation products is necessary in order to understand their qualities and characteristics. This article delivers a worldwide validation of hourly global horizontal irradiance derived from satellite imagery and reanalysis. The accuracies of 6 latest satellite-derived irradiance products (CAMS-RAD, NSRDB, SARAH-2, SARAH-E, CERES-SYN1deg, and Solcast) and 2 latest global reanalysis irradiance products (ERAS and MERRA-2) are verified against the complete records from 57 BSRN stations, over 27 years (1992-2018). This scope of validation is unprecedented in the field of solar energy. Moreover, the importance of using distribution-oriented verification approaches is emphasized. Such approaches go beyond the traditional measure-oriented verification approach, and thus can offer additional insights and flexibility to the verification problem. more
Author(s):
Kenny, Darragh; Fiedler, Stephanie
Publication title: SOLAR ENERGY
2022
| Volume: 232
2022
Abstract:
Model estimates of expected photovoltaic (PV) power production rely on accurate irradiance data. Reanalysis and satellite products freely provide irra… Model estimates of expected photovoltaic (PV) power production rely on accurate irradiance data. Reanalysis and satellite products freely provide irradiance data with a high temporal and spatial resolution including locations for which no ground-based measurements are available. We assess differences in such gridded irradiance data and quantify the subsequent bias propagation from individual radiation components to capacity factors in a contemporary PV model. PV power production is simulated based on four reanalysis (ERAS, COSMO-REA6, COSMO-REA6pp, COSMO-REA2) and three satellite products (CAMS, SARAH-2, CERES Syn1Deg). The results are compared against simulations using measurements from 30 weather stations of the German Weather Service. We compute metrics characterizing biases in seasonal and annual means, day-to-day variability and extremes in PV power. Our results highlight a bias of -1.4% (COSMO-REA6) to +8.2% (ERAS) in annual and spatial means of PV power production for Germany. No single data set is best in all metrics, although SARAH-2 and the postprocessed COSMO-REA6 data (COSMO-REA6pp) outperform the other products for many metrics. SARAH-2 yields good results in summer, but overestimates PV output in winter by 16% averaged across all stations. COSMO-REA6pp represents day-to-day variability in the PV power production of a simulated PV fleet best and has a particularly small bias of 0.5% in annual means. This is at least in parts due to compensating biases in local and seasonal means. Our results imply that gridded irradiance data should be used with caution for site assessments and ideally be complemented by local measurements. more