Author(s):
Bordoni, Massimiliano; Vivaldi, Valerio; Ciabatta, Luca; Brocca, Luca; Meisina, Claudia
Publication title: Bulletin of Engineering Geology and the Environment
2023
| Volume: 82 | Issue: 8
2023
Abstract:
ERA5-Land service has been released recently as an integral and operational component of Copernicus Climate Change Service. Within its set of climatol… ERA5-Land service has been released recently as an integral and operational component of Copernicus Climate Change Service. Within its set of climatological and atmospheric parameters, it provides soil moisture estimates at different soil depths, represeting an important tool for retrieving saturation degree for predicting natural hazards as shallow landslides. This paper represents an innovative attempt aiming to exploit the use of saturation degree derived from ERA5-Land soil moisture products in a data-driven model to predict the daily probability of occurence of shallow landslides. The study was carried out by investigating a multi-temporal inventory of shallow landslides occurred in Oltrepò Pavese (northern Italy). The achieved results follow: (i) ERA5-Land-derived saturation degree reconstructs well field trends measured in the study area until 1 m from ground; (ii) in agreement with the typical sliding surfaces depth, saturation degree values obtained since ERA5-Land 28–100 cm layer represent a significant predictor for the estimation of temporal probability of occurrence of shallow landslides, able especially to reduce overestimation of triggering events; (iii) saturation degree estimated by ERA5-Land 28–100 cm layer allows to detect soil hydrological conditions leading to triggering in the study area, represented by saturation degree in this layer close to complete saturation. Even if other works of research are required in different geological and geomorphological settings, this study demonstrates that ERA5-Land-derived saturation degree could be implemented to identify triggering conditions and to develop prediction methods of shallow landslides, thanks also to its free availability and constantly updating with a delay of 5 days. more
Author(s):
Villeneuve, E.; Chambon, P.; Fourrié, N.
Publication title: Atmospheric Measurement Techniques
2024
| Volume: 17 | Issue: 11
2024
Abstract:
In cloudy situations, infrared (IR) and microwave (MW) observations are complementary, with infrared observations being sensitive to small cloud dropl… In cloudy situations, infrared (IR) and microwave (MW) observations are complementary, with infrared observations being sensitive to small cloud droplets and ice particles and with microwave observations being sensitive to precipitation. This complementarity can lead to fruitful synergies in precipitation science (e.g., ). However, several sources of errors do exist in the treatment of infrared and microwave data that could prevent such synergy. This paper studies several of these sources to estimate their impact on retrievals. To do so, simulations from the radiative transfer (RT) for TIROS Operational Vertical Sounder (RTTOV v13) are used to build simulated observations. Indeed, we make use of a fully simulated framework to explain the impacts of the identified errors. A combination of infrared and microwave frequencies is built within a Bayesian inversion framework. Synergy is studied using different experiments: (i) with several sources of errors eliminated, (ii) with only one source of errors considered at a time and (iii) with all sources of errors together. The derived retrievals of frozen hydrometeors for each experiment are examined in a statistical study of 15g d in summer and 15 d in winter over the Atlantic Ocean. One of the main outcomes of the study is that the combination of infrared and microwave frequencies takes advantage of the strengths of both spectral ranges, leading to more accurate retrievals. Each source of error has more or less impact depending on the type of hydrometeor. Another outcome of the study is that, in all cases explored, even though the radiative transfer and numerical modeling errors may decrease the magnitude of benefits generated by the combination of infrared and microwave frequencies, the compromise remains positive. © 2024 Copernicus Publications. All rights reserved. more
Author(s):
Kassem, Youssef; Gokcekus, Hueseyin; Guvensoy, Ali
Publication title: ENERGIES
2021
| Volume: 14 | Issue: 22
2021
Abstract:
The growth of populations and economy in Northern Cyprus has led to continuing utilization of fossil fuels as the primary source of electricity, which… The growth of populations and economy in Northern Cyprus has led to continuing utilization of fossil fuels as the primary source of electricity, which will raise environmental pollution. Thus, utilizing renewable energy, particularly solar energy, might be a solution to minimize this issue. This paper presents the potential of grid-connected solar PV power generation at Near East University Hospital (NEU Hospital), one of the largest and leading medical facilities in Northern Cyprus, to meet the energy demand during the daytime to reduce energy bills. For this purpose, the first objective of the study is to evaluate the solar energy potential as a power source for the NEU Hospital based on four datasets (actual measurement, Satellite Application Facility on Climate Monitoring (CMSAF), Surface Radiation Data Set-Heliosat (SARAH), and ERA-5, produced by the European Centre for Medium-range Weather Forecast). The results showed that the solar resource of the selected location is categorized as excellent (class 5), that is, the global solar radiation is within the range of 1843.8-2035.9 kWH/m(2). The second objective is to investigate the impact of orientation angles on PV output, capacity factor, economic feasibility indicators, and CO2 emissions by using different PV modules. The results are compared with optimum orientation angles found by Photovoltaic Geographical Information System (PVGIS) simulation software. This objective was achieved by using RETScreen Expert software. The results demonstrated that the highest performance of the proposed system was achieved for orientation angles of 180 & DEG; (azimuth angle) and -35 & DEG; (tilt angle). Consequently, it is recommended that orientation angles, PV modules, and market prices are considered to maximize energy production and reduce electricity production costs. more
Author(s):
Dupuis, S.; Göttsche, F.-M.; Wunderle, S.
Publication title: Cryosphere
2024
| Volume: 18 | Issue: 12
2024
Abstract:
Land surface temperature (LST) has gained increased attention in cryospheric research. While various global satellite LST products are available, none… Land surface temperature (LST) has gained increased attention in cryospheric research. While various global satellite LST products are available, none of them is specially designed for the pan-Arctic region. Based on the recently published EUMETSAT Advanced Very High Resolution Radiometer (AVHRR) fundamental data record (FDR), a new LST product (1981-2021) with daily resolution is developed for the pan-Arctic region. Validation shows good accuracy with an average mean absolute error (MAE) of 1.71 K and a MAE range of 0.62-3.07 K against in situ LST data from the Surface Radiation Budget (SURFRAD) network and Karlsruhe Institute of Technology (KIT) sites. Long-term stability, a strong requirement for trend analysis, is assessed by comparing LST with air temperatures from ERA5-Land (T2M) and air temperature data from the EUSTACE (https://www.eustaceproject.org, last access: 17 December 2024) global station dataset. Long-term stability might not be fulfilled mainly due to the orbit drift of the NOAA satellites. Therefore, the analysis is split into two periods: the arctic winter months, which are unaffected by solar illumination and, therefore, orbital drift, and the summer months. The analysis for the winter months results in correlation values (r) of 0.44-0.83, whereas for the summer months (r) values range between 0.37-0.84. Analysis of anomaly differences revealed instabilities for the summer months at a few stations. The same stability analysis for the winter months revealed only one station with instabilities in comparison to station air temperature. Discrepancies between the temperature anomalies recorded at the stations and ERA5-Land T2M were also found. This highlights the limited influence of orbital drift on the LST product, with the winter months presenting good stability across all stations, which makes these data a valuable source for studying LST changes in the pan-Arctic region over the last 40 years. This study concludes by presenting LST trend maps (1981-2021) for the entire region, revealing distinct warming and cooling patterns. © 2024 Sonia Dupuis et al. more
Author(s):
Mol, W.B.; Knap, W.H.; Van Heerwaarden, C.C.
Publication title: Earth System Science Data
2023
| Volume: 15 | Issue: 5
2023
Abstract:
Surface solar irradiance varies on scales down to seconds, and detailed long-Term observational datasets of this variable are rare but in high demand.… Surface solar irradiance varies on scales down to seconds, and detailed long-Term observational datasets of this variable are rare but in high demand. Here, we present an observational dataset of global, direct, and diffuse solar irradiance sampled at 1ĝ€¯Hz as well as fully resolved variability until at least 0.1ĝ€¯Hz over a period of 10 years from the Baseline Surface Radiation Network (BSRN) station at Cabauw, the Netherlands. The dataset is complemented with irradiance variability classifications, clear-sky irradiance and aerosol reanalysis, information about the solar position, observations of clouds and sky type, and wind measurements up to 200ĝ€¯m above ground level. Statistics of variability derived from all time series include approximately 185ĝ€¯000 detected events of both cloud enhancement and cloud shadows. Additional observations from the Cabauw measurement site are freely available from the open-data platform of the Royal Netherlands Meteorological Institute. This paper describes the observational site, quality control, classification algorithm with validation, and the processing method of complementary products. Additionally, we discuss and showcase (potential) applications, including limitations due to sensor response time. These observations and derived statistics provide detailed information to aid research into how clouds and atmospheric composition influence solar irradiance variability as well as information to help validate models that are starting to resolve variability at higher fidelity. The main datasets are available at 10.5281/zenodo.7093164 and 10.5281/zenodo.7462362 ; the reader is referred to the "Code and data availability"section of this paper for the complete list. © Copyright: more
Author(s):
Saunders, Roger W.; Blackmore, Thomas A.; Candy, Brett; Francis, Peter N.; Hewison, Tim J.
Publication title: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
2021
| Volume: 59 | Issue: 6
2021
Abstract:
Satellite sounder infrared radiances are among the most important contributions to the global observing system and have been assimilated into global n… Satellite sounder infrared radiances are among the most important contributions to the global observing system and have been assimilated into global numerical weather prediction (NWP) analyses for many years. They are also used as fundamental climate data records for climate monitoring. Prior to assimilation or producing climate records, the radiances should have all residual instrument biases removed. One way of estimating the mean biases is to continuously monitor the measured radiances against the NWP model equivalent radiances. This article is an extension of one published in 2012 which documented these biases for three years but now the time span of the monitoring has extended to beyond ten years, allowing the long-term stability of the instruments to be assessed. Data from high-resolution infrared sounder (HIRS), Advanced Along Track Scanning Radiometer (AATSR), and Spinning Enhanced Visible and Infrared Imager (SEVIRI), radiometers; atmospheric infrared sounder (AIRS), a spectrometer; and infrared atmospheric sounding interferometer (IASI), an interferometer, were included. Changes in mean biases and standard deviations were used to investigate the temporal stability of the bias and radiometric noise of the instruments over ten years. A double difference technique was employed to remove the effect of changes or deficiencies in the NWP system and radiative transfer (RT) model, which can contribute to the biases. The IASI and AIRS radiances were stable but with a different bias between the two instruments due to different versions of the RT model used. The SEVIRI radiometers were stable in most channels with the exception of the 13.4 mu m channel. The HIRS instruments were subject to sudden changes in bias and increases in standard deviation compared with NWP simulations during the past decade. more
Author(s):
Anwar, Mohammad Ibna; Farhan, Khatib Zada; Alam, M. J. B.; Anwar, Aiyesha
Publication title: International Journal of Environment and Climate Change
2023
| Volume: 13 | Issue: 12
2023
Abstract:
The rising trend in fossil fuel prices and the depletion of natural resource reserves in the future force the authority of any country to find a more … The rising trend in fossil fuel prices and the depletion of natural resource reserves in the future force the authority of any country to find a more sustainable option for energy sources, so that future energy demand can be ensured for sustainable development. Assessing the trend and availability of sunshine duration (SD) at a spatiotemporal scale and the effect of different metrological parameters on the SD change is crucial to ensure the efficient utilization of solar energy, support the growth of renewable energy systems, and contribute to a sustainable future. In Saudi Arabia, The average monthly SD is 283 ± 18 hm<sup>-1</sup>, and there was a rising trend of SD that increased at a rate of 1.48 hy<sup>-1</sup> with a 95% confidence level. Most of the regions experienced an annual mean of SD between 3375 and 3754 hy<sup>-1</sup>, except for the southwest and the middle-eastern part where SD was between 3072 and 3375 hours in a year.  The highest mean monthly SD was 318 ± 39 hm-1 during the summer season, but the trend of SD changes over the years was downward ( -0.21 hy<sup>-1</sup>). The mean monthly SD was lowest (244 ± 38 hm<sup>-1</sup>) in the winter season, and the changing pattern of SD was on the rise at a rate of 0.26 hy<sup>-1</sup> with a 95% confidence level. There was a decline in SD across the country between 1983 and 1998, whereas from 2000 onward the country experienced an upward trend in SD. Relative humidity (R = -0.53, p < 0.01) and cloud cover (R = -0.42, p < 0.05) as potential factors have a strong negative correlation with SD, whereas wind speed (R = 0.06, p > 0.1) and temperature (R = 0.12, p > 0.1) have a positive correlation with SD in the region. more
Author(s):
Bouillon, Marie; Safieddine, Sarah; Hadji-Lazaro, Juliette; Whitburn, Simon; Clarisse, Lieven; Doutriaux-Boucher, Marie; Coppens, Dorothée; August, Thomas; Jacquette, Elsa; Clerbaux, Cathy
Publication title: Remote Sensing
2020
| Volume: 12 | Issue: 15
2020
Abstract:
The Infrared Atmospheric Sounding Interferometers (IASIs) are three instruments flying on board the Metop satellites, launched in 2006 (IASI-A), 2012 … The Infrared Atmospheric Sounding Interferometers (IASIs) are three instruments flying on board the Metop satellites, launched in 2006 (IASI-A), 2012 (IASI-B), and 2018 (IASI-C). They measure infrared radiance from the Earth and atmosphere system, from which the atmospheric composition and temperature can be retrieved using dedicated algorithms, forming the Level 2 (L2) product. The operational near real-time processing of IASI data is conducted by the EUropean organisation for the exploitation of METeorological SATellites (EUMETSAT). It has improved over time, but due to IASI’s large data flow, the whole dataset has not yet been reprocessed backwards. A necessary step that must be completed before initiating this reprocessing is to uniformize the IASI radiance record (Level 1C), which has also changed with time due to various instrumental and software modifications. In 2019, EUMETSAT released a reprocessed IASI-A 2007–2017 radiance dataset that is consistent with both the L1C product generated after 2017 and with IASI-B. First, this study aimed to assess the changes in radiance associated with this update by comparing the operational and reprocessed datasets. The differences in the brightness temperature ranged from 0.02 K at 700 cm−1 to 0.1 K at 2200 cm−1. Additionally, two major updates in 2010 and 2013 were seen to have the largest impact. Then, we investigated the effects on the retrieved temperatures due to successive upgrades to the Level 2 processing chain. We compared IASI L2 with ERA5 reanalysis temperatures. We found differences of ~5–10 K at the surface and between 1 and 5 K in the atmosphere. These differences decreased abruptly after the release of the IASI L2 processor version 6 in 2014. These results suggest that it is not recommended to use the IASI inhomogeneous temperature products for trend analysis, both for temperature and trace gas trends. more
Author(s):
Clerbaux, N.; Akkermans, T.; Baudrez, E.; Blazquez, A.V.; Moutier, W.; Moreels, J.; Aebi, C.
Publication title: Remote Sensing
2020
| Volume: 12 | Issue: 6
2020
Abstract:
Data from the Advanced Very High Resolution Radiometer (AVHRR) have been used to create several long-duration data records of geophysical variables de… Data from the Advanced Very High Resolution Radiometer (AVHRR) have been used to create several long-duration data records of geophysical variables describing the atmosphere and land and water surfaces. In the Climate Monitoring Satellite Application Facility (CM SAF) project, AVHRR data are used to derive the Cloud, Albedo, and Radiation (CLARA) climate data records of radiation components (i.a., surface albedo) and cloud properties (i.a., cloud cover). This work describes the methodology implemented for the additional estimation of the Outgoing Longwave Radiation (OLR), an important Earth radiation budget component, that is consistent with the other CLARA variables. A first step is the estimation of the instantaneous OLR from the AVHRR observations. This is done by regressions on a large database of collocated observations between AVHRR Channel 4 (10.8 μm) and 5 (12 μm) and the OLR from the Clouds and Earth's Radiant Energy System (CERES) instruments. We investigate the applicability of this method to the first generation of AVHRR instrument (AVHRR/1) for which no Channel 5 observation is available. A second step concerns the estimation of daily and monthly OLR from the instantaneous AVHRR overpasses. This step is especially important given the changes in the local time of the observations due to the orbital drift of the NOAA satellites. We investigate the use of OLR in the ERA5 reanalysis to estimate the diurnal variation. The developed approach proves to be valuable to model the diurnal change in OLR due to day/night time warming/cooling over clear land. Finally, the resulting monthly mean AVHRR OLR product is intercompared with the CERES monthly mean product. For a typical configuration with one morning and one afternoon AVHRR observation, the Root Mean Square (RMS) difference with CERES monthly mean OLR is about 2 Wm-2 at 1 x 1 resolution. We quantify the degradation of the OLR product when only one AVHRR instrument is available (as is the case for some periods in the 1980s) and also the improvement when more instruments are available (e.g., using METOP-A, NOAA-15, NOAA-18, and NOAA-19 in 2012). The degradation of the OLR product from AVHRR/1 instruments is also quantified, which is done by "masking" the Channel 5 observations. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. more
Author(s):
Esau, Igor; Pettersson, Lasse H.; Cancet, Mathilde; Chapron, Bertrand; Chernokulsky, Alexander; Donlon, Craig; Sizov, Oleg; Soromotin, Andrei; Johannesen, Johnny A.
Publication title: Remote Sensing
2023
| Volume: 15 | Issue: 5
2023
Abstract:
Arctic climate change has already resulted in amplified and accelerated regional warming, or the Arctic amplification. Satellite observations have cap… Arctic climate change has already resulted in amplified and accelerated regional warming, or the Arctic amplification. Satellite observations have captured this climate phenomenon in its development and in sufficient spatial details. As such, these observations have been—and still are—indispensable for monitoring of the amplification in this remote and inhospitable region, which is sparsely covered with ground observations. This study synthesizes the key contributions of satellite observations into an understanding and characterization of the amplification. The study reveals that the satellites were able to capture a number of important environmental transitions in the region that both precede and follow the emergence of the apparent amplification. Among those transitions, we find a rapid decline in the multiyear sea ice and subsequent changes in the surface radiation balance. Satellites have witnessed the impact of the amplification on phytoplankton and vegetation productivity as well as on human activity and infrastructure. Satellite missions of the European Space Agency (ESA) are increasingly contributing to amplification monitoring and assessment. The ESA Climate Change Initiative has become an essential provider of long-term climatic-quality remote-sensing data products for essential climate variables. Still, such synthesis has found that additional efforts are needed to improve cross-sensor calibrations and retrieval algorithms and to reduce uncertainties. As the amplification is set to continue into the 21st century, a new generation of satellite instruments with improved revisiting time and spectral and spatial resolutions are in high demand in both research and stakeholders’ communities. more