10 research outputs found
Spatial correlation structures of wind speed and irradiance in Europe as modelled in regional climate models and the ERA5 reanalysis
Objective & Background
For comprehensive energy systems analysis considering high shares of weather-dependent renewables, the spatiotemporal characteristics of meteorological input data (in particular, wind speed and irradiance) are of considerable interest. Studies aiming to evaluate the potential effects of future climate change rely on model-based projections of these variables. In order to reach as high a spatiotemporal resolution as possible, global climate models (GCM) can be used as drivers for regional climate models (RCM). In doing so, global climate effects are considered on large scales, while the higher resolution computations are limited to the domain of interest. Here, we analyse such regional climate model outputs as well as reanalysis data with regards to their suitability in energy systems analysis, using spatial correlation structures of the wind and solar resource anomalies.
Method
Based on 10 years of historical experiments of EURO-CORDEX regional climate model output and ERA5 reanalyses, we compute climate anomalies of both wind speed and irradiance for each point in space and time by subtracting the multi-year mean of each point from the instantaneous values at that point. In doing so, we largely remove effects of seasonal and diurnal cycles, especially in the case of irradiance. From each of these wind speed and irradiance anomaly fields, we sample distinct two-dimensional correlation structures (i.e., maps of the correlation coefficient between each pixel’s time series and a reference pixel’s series). Increasing the number of reference pixels hence increases the number of spatial correlation structures available in the analysis. We finally estimate the degree of similarity between the spatial correlation structures of each EURO-CORDEX member and its corresponding ERA5 counterpart using the coefficient of pattern correlation (i.e., the correlation coefficient of the mapped spatial correlation structures in vector form).
Principal Findings
Kernel density estimates and box-plot statistics of all available pattern correlations show that the wind speed anomaly spatial correlation structures tend to be better represented than their irradiance counterparts. Between different driving global models, the performance is relatively similar for wind speed anomaly correlation structures, while solar irradiance anomaly structures can be associated with a few unusually low pattern correlations for some global models. In terms of regional climate models, these cases of low pattern correlation values are largely associated with the SMHI-RCA4 regional model during the summer.
Discussion
This initial comparison of CORDEX model output and ERA5 reanalysis based on correlation structures in wind speed and solar irradiance anomalies allows to help in the selection of global and regional models when compiling an ensemble for use in energy systems analysis. In this context, the spatial correlation structures of wind speed need less attention when selecting model outputs, while the irradiance anomaly projections of the regional climate model SMHI-RCA4 should be handled with caution. Increasing the number of reference points used in the spatial correlation structure calculations may lead to further insights regarding potential regional differences in CORDEX model performances
M. Adami Historia ecclesiastica : continens Religionis propagatae gesta, quae à temporibus Karoli Magni, vsque ad Henricum IIII acciderunt, in Ecclesia non tam Hamburgensi quàm Bremensi, vicinisque locis Septentrionalibus... / eiusdem auctoris libellus De situ Daniae & reliquarum quae trans Daniam sunt regionum natura...
Marca tip. en port.Grab. calc. en v. de port.Enc. Perg.Sign.: *6, A-Y4, Z
Confrontation de l'évolution de l'Ile d'Helgoland et de ses environs avec les cartes „historiques“ de Johannes Mejer
Code and data used for the study: 'BioDeepTime: a database of biodiversity time series for modern and fossil assemblages'
The repository includes code and data to reproduce the results in the manuscript ‘BioDeepTime: a database of biodiversity time series for modern and fossil assemblages' by Smith et al. (analysis_biodeeptime.zip)
BioDeepTime: database and compilation code
The archive includes copies, compilation code, documentation and temporary data files for the BioDeepTime database. Deposited files: Relational database in SQLite format: biodeeptime_sqlite.zip. Denormalized database in zipped .csv format: biodeeptime_csv.zip Denormalized database in zipped .parquet (v1.0) format: biodeeptime_parquet.zip. Denormalized database in .rds (R version 4.0) format: biodeeptime.rds. Description of tables and columns: biodeeptime.md. Database schema: schema.pdf. Synonymy of sources: Synonymy of sources.xlsx. Change log and known issues: NEWS.md Compilation files: bdt_compilation.zip References in .csv format: references.csv Bchron ages calculated for Neotoma: neotoma_bchron.rds This repository accompanies the study BioDeepTime: a database of biodiversity time series for modern and fossil assemblages by Smith et al. (pending publication) and will be updated after a successful peer-review
Ambiguous pots:Everyday practice, migration and materiality.The case of medieval Baltic ware on the island of Bornholm (Denmark)
Archaeologists routinely deal with the remains of everyday life. Yet the significance and dimensions of daily practices are rarely reflected upon. Merging Bourdieu’s theory of practice, recent theories of everyday life and the materiality approach in archaeology, this study addresses the potential importance of daily practices and mundane objects in dealing with a rupture caused by migration. As a case study I use an example of medieval (eleventh century) Western Slavic migration to the island of Bornholm (Denmark) and production and daily handling of ceramic pots, the so-called Baltic ware. I explore the possible background to the introduction of the new pottery style, its significance for the local population of the island and above all the meanings these types of ceramics could have had for the immigrant Slavs