scholarly journals Preparing the CAMS Radiation Service for MTG

2021 ◽  
Author(s):  
Marion Schroedter-Homscheidt ◽  
Faiza Azam ◽  
Jethro Betcke ◽  
Hartwig Deneke ◽  
Mireille Lefèvre ◽  
...  
Keyword(s):  
Time Series ◽  
Quality Control ◽  
Method Development ◽  
Model Output ◽  
Clear Sky ◽  
Cloud Properties ◽  
Monitoring Service ◽  
Radiation Time ◽  
Insight Into ◽  
Temporal Coverage

<p>The Copernicus Atmospheric Monitoring Service (CAMS) provides a surface solar irradiance service which is currently derived from Meteosat Second Generation (MSG). The service combines satellite data products with numerical model output from CAMS on aerosols, water vapour and ozone in order to provide both clear-sky and all-sky radiation time series with availability from 2004 until yesterday. A regular quality control of input parameters, quarterly benchmarking against ground measurements and automatic consistency checks ensures the data quality. To anticipate the increase in resolution that will occur with the commissioning of MTG, it is necessary to enhance methods currently used in CAMS.</p><p>The recent development focuses on the assessment and improvement of cloud retrieval products from APOLLO_NG in irradiance retrieval schemes. Such a validation against ground-based surface solar irradiances provides insight into the use of probabilistic cloud masking, specific results for pixels with small COD values below 5, as well as in partly cloudy pixel conditions. Such conditions are often neglected in existing cloud retrieval validation studies due to the expected large uncertainties of cloud properties. But they cannot be omitted in irradiance retrieval schemes for solar energy sector users as complete temporal coverage is required.</p><p>Such cloud situations may additionally be better characterized in future with the help of spatially higher resolved channels. Using e.g. SEVIRI’s HRV channel is known to be beneficial in cloud index based irradiance retrieval schemes, but has not been evaluated yet for cloud physical retrieval based irradiance schemes. Results from such a method development for the HRV channel in preparation for MTG, Himawari-8, and GOES-R channels will be presented.</p>

Variability class dependent evaluation of the CAMS Solar Radiation Service

2021 ◽  
Author(s):  
Faiza Azam ◽  
Jethro Betcke ◽  
Marion Schroedter-Homscheidt ◽  
Mireille Lefevre ◽  
Yves-Marie Saint-Drenan ◽  
...  
Keyword(s):  
Time Series ◽  
Quality Control ◽  
Solar Radiation ◽  
Temporal Variability ◽  
Solar Surface ◽  
Model Output ◽  
Energy Applications ◽  
Service Evolution ◽  
Monitoring Service ◽  
The Impact

<p>The Copernicus Atmospheric Monitoring Service (CAMS) offers Solar radiation services (CRS) providing information on surface solar irradiance (SSI). The service is currently derived from Meteosat Second Generation (MSG) and the service evolution includes its extension to other parts of the globe. CRS provides clear and all sky time series combining satellite data products with numerical model output from CAMS on aerosols, water vapour and ozone. These products are available from 2004 until yesterday. A regular quality control of input parameters, quarterly benchmarking against ground measurements and automatic consistency checks ensure the service quality.</p> <p>Variability of solar surface irradiances in the 1-minute range is of interest especially for solar energy applications. The variability classes can be defined based on ground as well as satellite-based measurements. This study will present the evaluation of the CAMS CRS based on the eight variability classes derived from ground observations of direct normal irradiation (DNI) (Schroedter-Homscheidt et al., 2018). Such an analysis will help assess the impact of recent improvements in the derivation of all sky irradiance under different cloudy conditions.</p> <p>References:</p> <p>Schroedter-Homscheidt, M., S. Jung, M. Kosmale, 2018: Classifying ground-measured 1 minute temporal variability within hourly intervals for direct normal irradiances. – Meteorol. Z. 27, 2, 160–179. DOI:10.1127/metz/2018/0875.</p>

scholarly journals Reconstruction of global solar radiation time series from 1933 to 2013 at the Izaña Atmospheric Observatory

2014 ◽  
Vol 7 (9) ◽  
pp. 3139-3150 ◽  
Author(s):  
R. D. García ◽  
E. Cuevas ◽  
O. E. García ◽  
V. E. Cachorro ◽  
P. Pallé ◽  
...  
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
North Atlantic ◽  
Sunshine Duration ◽  
Global Solar Radiation ◽  
Global Scale ◽  
High Mountain ◽  
Atlantic Region ◽  
Clear Sky ◽  
Radiation Time

Abstract. This paper presents the reconstruction of the 80-year time series of daily global solar radiation (GSR) at the subtropical high-mountain Izaña Atmospheric Observatory (IZO) located in Tenerife (The Canary Islands, Spain). For this purpose, we combine GSR estimates from sunshine duration (SD) data using the Ångström–Prescott method over the 1933/1991 period, and GSR observations directly performed by pyranometers between 1992 and 2013. Since GSR measurements have been used as a reference, a strict quality control has been applied based on principles of physical limits and comparison with LibRadtran model. By comparing with high quality GSR measurements, the precision and consistency over time of GSR estimations from SD data have been successfully documented. We obtain an overall root mean square error (RMSE) of 9.2% and an agreement between the variances of GSR estimations and GSR measurements within 92%. Nonetheless, this agreement significantly increases when the GSR estimation is done considering different daily fractions of clear sky (FCS). In that case, RMSE is reduced by half, to about 4.5%, when considering percentages of FCS > 40% (~ 90% of days in the testing period). Furthermore, we prove that the GSR estimations can monitor the GSR anomalies in consistency with GSR measurements and, then, can be suitable for reconstructing solar radiation time series. The reconstructed IZO GSR time series between 1933 and 2013 confirms change points and periods of increases/decreases of solar radiation at Earth's surface observed at a global scale, such as the early brightening, dimming and brightening. This fact supports the consistency of the IZO GSR time series presented in this work, which may be a reference for solar radiation studies in the subtropical North Atlantic region.

scholarly journals Re-construction of global solar radiation time series from 1933 to 2013 at the Izaña Atmospheric Observatory

2014 ◽  
Vol 7 (4) ◽  
pp. 4191-4227 ◽  
Author(s):  
R. D. García ◽  
E. Cuevas ◽  
O. E. García ◽  
V. E. Cachorro ◽  
P. Pallé ◽  
...  
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
North Atlantic ◽  
Sunshine Duration ◽  
Global Solar Radiation ◽  
Global Scale ◽  
High Mountain ◽  
Clear Sky ◽  
Downward Radiation ◽  
Radiation Time

Abstract. This paper presents the re-construction of the 80 year time series of daily global shortwave downward radiation (SDR) at the subtropical high-mountain Izaña Atmospheric Observatory (IZO, Spain). For this purpose, we combine SDR estimates from sunshine duration (SD) data using the Ångström–Prescott method over the 1933/1991 period, and SDR observations directly performed by pyranometers between 1992 and 2013. Since SDR measurements have been used as a reference, a strict quality control has been applied, when it was not possible data have been re-calibrated by using the LibRadtran model. By comparing to high quality SDR measurements, the precision and consistency over time of SDR estimations from SD data have successfully been documented. We obtain a overall root mean square error (RMSE) of 9.2% and an agreement between the variances of SDR estimations and SDR measurements within 92% (correlation coefficient of 0.96). Nonetheless, this agreement significantly increases when the SDR estimation is done considering different daily fractions of clear sky (FCS). In that case, RMSE is reduced by half, up to about 4.5%, when considering percentages of FCS > 40% (90% of days in the testing period). Furthermore, we prove that the SDR estimations can monitor the SDR anomalies in consistency with SDR measurements and, then, can be suitable for re-constructing solar radiation time series. The re-constructed IZO global SDR time series between 1933 and 2013 confirms discontinuities and periods of increases/decreases of solar radiation at Earth's surface observed at a global scale, such as the early brightening, dimming and brightening. This fact supports the consistency of the IZO SDR time series presented in this work, which may be a reference for solar radiation studies in the subtropical North Atlantic region.

Death and Disposal Locations of Serial Homicides: The Effect on Recovery Timeframes

2021 ◽  
pp. 108876792110068
Author(s):  
Brendan Chapman ◽  
Cody Raymer ◽  
David A. Keatley
Keyword(s):  
Time Series ◽  
Exploratory Study ◽  
Serial Killers ◽  
Disposal Site ◽  
Time Since Death ◽  
Forensic Evidence ◽  
Hostile Environments ◽  
Case Data ◽  
Insight Into ◽  
Homicide Case

Many factors affect the solvability of homicides, including body disposal location and time between death and recovery. The aim of this exploratory study was to probe a number of spatiotemporal variables for trends across a subset of solved homicide case data from 54 North American serial killers, active between 1920 and 2016 (125 solved cases) to identify areas for further research. We investigated murder site and body disposal site as location variables with eight subcategories across eight discrete time series, seeking insight into how these factors may affect the early stages of an investigation and (therefore by inference) solvability. The findings showed that bodies recovered after 48 hours are more likely discovered outdoor while those discovered within 24 hours, within the victim’s residence. This has implications for the ability to recover forensic evidence when bodes are located after a prolonged time since death as well as in more hostile environments.

Dynamic Modeling of Solar Radiation Disturbances Based on a Biomimetic Cloud Shading Model

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Jesús García ◽  
Iván Portnoy ◽  
Ricardo Vasquez Padilla ◽  
Marco E. Sanjuan
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
Control Strategies ◽  
Ground Level ◽  
Direct Solar Radiation ◽  
Complex Phenomenon ◽  
Two Dimensional ◽  
Multi Objective Optimization ◽  
Tuning Parameters ◽  
Radiation Time

Variation in direct solar radiation is one of the main disturbances that any solar system must handle to maintain efficiency at acceptable levels. As known, solar radiation profiles change due to earth's movements. Even though this change is not manipulable, its behavior is predictable. However, at ground level, direct solar radiation mainly varies due to the effect of clouds, which is a complex phenomenon not easily predictable. In this paper, dynamic solar radiation time series in a two-dimensional (2D) spatial domain are obtained using a biomimetic cloud-shading model. The model is tuned and compared against available measurement time series. The procedure uses an objective function based on statistical indexes that allow extracting the most important characteristics of an actual set of curves. Then, a multi-objective optimization algorithm finds the tuning parameters of the model that better fit data. The results showed that it is possible to obtain responses similar to real direct solar radiation transients using the biomimetic model, which is useful for other studies such as testing control strategies in solar thermal plants.

Cloud Properties over the North Slope of Alaska: Identifying the Prevailing Meteorological Regimes

2012 ◽  
Vol 25 (23) ◽  
pp. 8238-8258 ◽  
Author(s):  
Johannes Mülmenstädt ◽  
Dan Lubin ◽  
Lynn M. Russell ◽  
Andrew M. Vogelmann
Keyword(s):  
Time Series ◽  
Climate Model ◽  
North Slope ◽  
Test Cases ◽  
Synoptic Scale ◽  
Long Time Series ◽  
The North ◽  
Cloud Properties ◽  
North Slope Of Alaska ◽  
Long Time

Abstract Long time series of Arctic atmospheric measurements are assembled into meteorological categories that can serve as test cases for climate model evaluation. The meteorological categories are established by applying an objective k-means clustering algorithm to 11 years of standard surface-meteorological observations collected from 1 January 2000 to 31 December 2010 at the North Slope of Alaska (NSA) site of the U.S. Department of Energy Atmospheric Radiation Measurement Program (ARM). Four meteorological categories emerge. These meteorological categories constitute the first classification by meteorological regime of a long time series of Arctic meteorological conditions. The synoptic-scale patterns associated with each category, which include well-known synoptic features such as the Aleutian low and Beaufort Sea high, are used to explain the conditions at the NSA site. Cloud properties, which are not used as inputs to the k-means clustering, are found to differ significantly between the regimes and are also well explained by the synoptic-scale influences in each regime. Since the data available at the ARM NSA site include a wealth of cloud observations, this classification is well suited for model–observation comparison studies. Each category comprises an ensemble of test cases covering a representative range in variables describing atmospheric structure, moisture content, and cloud properties. This classification is offered as a complement to standard case-study evaluation of climate model parameterizations, in which models are compared against limited realizations of the Earth–atmosphere system (e.g., from detailed aircraft measurements).

scholarly journals Expanding HadISD: quality-controlled, sub-daily station data from 1931

2016 ◽  
Author(s):  
Robert J. H. Dunn ◽  
Kate M. Willett ◽  
David E. Parker ◽  
Lorna Mitchell
Keyword(s):  
Quality Control ◽  
Wind Speed ◽  
Time Range ◽  
Underlying Structure ◽  
Control Procedure ◽  
Future Projections ◽  
Quality Control Procedure ◽  
Temporal Coverage ◽  
Extremes Of Temperature ◽  
Selection Of

Abstract. HadISD is a sub-daily, station-based, quality-controlled dataset designed to study past extremes of temperature, pressure and humidity and allow comparisons to future projections. Herein we describe the first major update to the HadISD dataset. The temporal coverage of the dataset has been extended to 1931 to present, doubling the time range over which data are provided. Improvements made to the station selection and merging procedures result in 7677 stations being provided in version 2.0.0.2015p of this dataset. The selection of stations to merge together making composites has also been improved and made more robust. The underlying structure of the quality control procedure is the same as for HadISD.1.0.x, but a number of improvements have been implemented in individual tests. Also, more detailed quality control tests for wind speed and direction have been added. The data will be made available as netCDF files at www.metoffice.gov.uk/hadobs/hadisd and updated annually.

scholarly journals A New Method for Fusion of Measured and Model-derived Solar Radiation Time-series

2014 ◽  
Vol 48 ◽  
pp. 1617-1626 ◽  
Author(s):  
Theresa Mieslinger ◽  
Felix Ament ◽  
Kaushal Chhatbar ◽  
Richard Meyer
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
New Method ◽  
Radiation Time

scholarly journals Observing the timescales of aerosol-cloud interactions in snapshot satellite images

2020 ◽  
Author(s):  
Edward Gryspeerdt ◽  
Tom Goren ◽  
Tristan W. P. Smith
Keyword(s):  
Satellite Images ◽  
Strong Impact ◽  
Natural Experiments ◽  
Liquid Water Path ◽  
Clear Sky ◽  
Cloud Properties ◽  
Aerosol Cloud Interactions ◽  
Aerosol Source ◽  
Retrieval Bias ◽  
Ship Emission

Abstract. The response of cloud processes to an aerosol perturbation is one of the largest uncertainties in the anthropogenic forcing of the climate. It occurs at a variety of timescales, from the near-instantaneous Twomey effect, to the longer timescales required for cloud adjustments. Understanding the temporal evolution of cloud properties following an aerosol perturbation is necessary to interpret the results of so-called "natural experiments" from a known aerosol source, such as a ship or industrial site. This work uses reanalysis windfields and ship emission information matched to observations of shiptracks to measure the timescales of cloud responses to aerosol in instantaneous (or "snapshot") images taken by polar-orbiting satellites. As found in previous studies, the local meteorological environment is shown to have a strong impact on the occurrence and properties of shiptracks, but there is a strong time dependence in their properties. The largest droplet number concentration (Nd) responses are found within three hours of emission, while cloud adjustments continue to evolve over periods of ten hours or more. Cloud fraction is increased within the early life of shiptracks, with the formation of shiptracks in otherwise clear skies indicating that around 5–10 % of clear-sky cases in this region may be aerosol-limited. The liquid water path (LWP) enhancement and the Nd-LWP sensitivity are also time dependent and strong functions of the background cloud and meteorological state. The near-instant response of the LWP within shiptracks may be evidence of a retrieval bias in previous estimates of the LWP response to aerosol derived from natural experiments. These results highlight the importance of temporal development and the background cloud field for quantifying the aerosol impact on clouds, even in situations where the aerosol perturbation is clear.

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