Simulated 2D residual velocity fields in the inner German Bight were subjected to Principal Component Analysis (PCA). Residual currents were obtained from coastDat2 barotropic 2D simulations with the hydrodynamic model TRIM-NP V2.1.22 in barotropic 2D mode on a Cartesian grid (1.6km spatial resolution) stored on an hourly basis for the years 1948 - 2012 (doi:10.1594/WDCC/coastDat-2_TRIM-NP-2d) and later extended until August 2015. The present analysis refers to the period Jan 1958 - Aug 2015. The spatial domain considered is the region to the east of 6 degrees east and to the south of 55.6 degrees north. All grid nodes with a bathymetry of less than 10m were excluded. Residual velocities were calculated in two different ways: 1.) as 25h means, 2.) as monthly means. Both types of residual current data are available from * RESIDUAL_CURRENTS_195801_201508 The directory contains sub-directories for years and months. Daily residual currents for the 13th of September 1974, for instance, are stored in * RESIDUAL_CURRENTS_195801_201508/YEAR_1974/MONTH_09/TRIM2D_1974_09_13_means.nc while monthly mean residual currents for September 1974 are stored in: * RESIDUAL_CURRENTS_195801_201508/YEAR_1974/TRIM2D_1974_09_means.nc All current fields provided were interpolated from the original Cartesian model grid to a more convenient regular geographical grid (116x76 nodes). Mean residual currents are stored in: * mean_residual_currents.nc This data set contains residual velocities both on original Cartesian grid nodes and interpolated to the geographical grid. An example plot is provided: * mean_residual_currents.png For PCA, two residual velocity components from each of 12133 Cartesian grid nodes were combined into one data vector (length 2x12133), referring to 21061 daily or 692 monthly time levels. Results of two independent PCAs for either daily or monthly mean fields are stored in: * PCA_daily_residual_currents.nc * PCA_monthly_residual_currents.nc Files contain three leading Principal Components (PCs) and corresponding Emipirical Orthogonal Functions (EOFs). Again EOFs were also interpolated to a regular geographical grid. PC time series are also stored in plain ASCII format: * PCs_daily.txt * PCs_monthly.txt For monthly fields the number N of variables (N=2x12133) is much larger than the number T of time levels (T=692). Therefore, to reduce computational demands, the roles of time and space were formally interchanged. Having conducted the PCA the EOFs were then transformed back to the original spatial coordinates (cf. Section 12.2.6 in von Storch and Zwiers (1999), Statistical Analysis in Climate Research, Cambridge University Press). A much larger number of time levels made even this approach prohibitive for the full set of daily data. Therefore, PCAs were performed for six sub-periods (1958-1965, 1966-1975, 1976-1985, 1986-1995, 1996-2005, 2006-2015(Aug)) independently. EOFs obtained from these six sub-periods were then averaged to obtain EOFs representative for the whole period. Corresponding PCs were calculated by projecting daily fields onto these average EOFs. IMPORTANT: In contrast with PCA of monthly data, the PCA of daily data INVOLVES SOME APPROXIMATIONS! EOFs on the original nodes were normalized to have unit lengths. The following figures, * daily_EOF1.png * daily_EOF2.png * daily_EOF3.png show the first three EOFs obtained from daily data, assuming that corresponding PCs have the value of one standard deviation. The following two plots, * monthly_EOF1.png * monthly_EOF2.png show the leading EOFs for monthly mean data. EOF3 is omitted as it represents just a very small percentage of overall variance (1.7%).
Hindcast simulation has been performed for reconstruction of meso-scale weather systems, especially of intense storms by using the global atmospheric model ECHAM6 in its version 6.1.00 (CMIP5), the spectral nudging technique and NCEP reanalysis as forcing data. Horizonatal resolution: (768x384) gridpoints (T255L95), vertical resolution: 95 levels. Time period: 1948 - 2015 april. The output from the model run: /work/gg0301/g260070/ECHAM6/echam-6.1.00/experiments/echam6_t255l95_sn_ncep1/scripts on the HLRE-2 Blizzard and the Original-Outputs of the 8 ECHAM6-streams were named and differed by their suffixes: echam6_t255l95_sn_ncep1_199212.01_co2 echam6_t255l95_sn_ncep1_199212.01_echam echam6_t255l95_sn_ncep1_199212.01_jsbach echam6_t255l95_sn_ncep1_199212.01_land echam6_t255l95_sn_ncep1_199212.01_nudg echam6_t255l95_sn_ncep1_199212.01_surf echam6_t255l95_sn_ncep1_199212.01_veg echam6_t255l95_sn_ncep1_199212.01_vphysc
This is a hydrodynamic hindcast for the Baltic Sea over the period 1958-2011. The simulation has been performed with the hydrodynamic model TRIM-NP V2.1 in barotropic 2D mode. Water level and current component fields are stored hourly. The model is set up on an equidistant Cartesian grid cascade with the center near Helgoland (7.88 E, 54.18 N) for the coarsest grid (12.8km resolution) (http://dx.doi.org/doi:10.1594/WDCC/coastDat-2_TRIM-NP-2d). Further model results from three nested grids (6.4km,3.2km, 1.6km resolution) for the Baltic Sea are hourly available for the period 1958-2011.
This is a hydrodynamic hindcast for the North Sea and the Northeast Atlantic over the period 1948-2015. The simulation has been performed with the hydrodynamic model TRIM-NP V2.1.22 in barotropic 2D mode. Water level and current component fields are stored hourly. The model is set up on an equidistant Cartesian grid cascade with the center near Helgoland (7.88 E, 54.18 N). The coarsest grid with 12.8 km resolution covers the area from 20 W to 30 E and from 42 N to 65 N. Further 3 nested grids better resolve the North Sea (with 6.4km), southern North Sea (with 3.2km) and the German Bight (with 1.6km). Model data from grid 1 and grid 4 are available in this data bank. Please contact the authors for data from grid 2 and grid 3. Time supplement procedure: data over period 2013-2015 appended 04-05-2016
This is a North Sea wave hindcast for the period 1949-2014. The simulation has been performed with the wave model WAM Version 4.5.4. The model domain covers the area from 51N to 59N and 4.75W to 13E, with a spatial resolution of 0.05 degree latitude x 0.075 degree longitude (approx. 3 by 3 nautical miles). Integrated parameter derived from 2D spectra are available every hour. Atmospheric forcing was obtained from an atmospheric hindcast with COSMO-CLM (doi:10.1594/WDCC/coastDat-2_COSMO-CLM) driven by the NCEP/NCAR Reanalysis 1 data set. Lateral boundary conditions were obtained from corresponding coarse grid hindcast covering most of the Northeast Atlantic driven by the same atmospheric forcing.
This is an atmospheric hourly hindcast for the German Bight using COSMO-CLM version 5.00_clm2 from 1948-August 2015 (http://www.cosmo-model.org/content/model/documentation/core/default.htm). The model uses a rotated grid with 250 x 180 grid points and a grid point distance of 0.025 degrees, the rotated North pole is located at 172.97 W, 34.925 N. The forcing is coastDat2 doi:10.1594/WDCC/coastDat-2_COSMO-CLM . In rotated coordinates the model area extends from 2.25 W to 2.25 E, 3.125 S to 3.125 N, in geographical coordinates this corresponds to about 1.3 E to 12.8 E, 52.7 N to 57.3 N.
These are two atmospheric hourly hindcasts for Siberia using COSMO-CLM (CCLM) version 4.8_clm_11 with spectral nudging. The hindcast CCLM_sib_NCEP1 covers a period from 1948-2010 and has been performed using NCEP-R1 Reanalysis as global atmospheric forcing for the initialization and regional boundaries. The hindcast CCLM_sib_ERA40 was driven by ERA-40 from 1959-2001. CCLM uses a rotated grid with 76 x 76 grid points (without the sponge zone) and a grid point distance of 0.44 degrees, the rotated North pole is located at 75 W, 35 N. In rotated coordinates the model area extends from 14.72 W to 18.28 E, 9.72 S to 27.68 N, in geographical coordinates this corresponds to about 41.2 W to 174.9 E, 42 N to 82.7 N. For all variables lon, lat and the value of the 18:00 time record for the last day is added. The output from the model run: Blizzard
This is an atmospheric hourly hindcast for Western Europe and the North Atlantic using COSMO-CLM version 4.8_clm_11 with spectral nudging from 1948-2012. The model uses a rotated grid with 254 x 248 grid points and a grid point distance of 0.22 degrees, the rotated North pole is located at 170 W, 35 N. In rotated coordinates the model area extends from 30.44 W to 25.22 E, 25.72 S to 28.62 N, in geographical coordinates this corresponds to about 68 W to 82 E, 25.6 N to 81.4 N.
This is a hydrodynamic hindcast for the North Sea and the Northeast Atlantic over the period 1948-2015. The simulation has been performed with the hydrodynamic model TRIM-NP V2.1.22 in barotropic 2D mode. Water level and current component fields are stored hourly. The model is set up on an equidistant Cartesian grid cascade with the center near Helgoland (7.88 E, 54.18 N). The coarsest grid with 12.8 km resolution covers the area from 20 W to 30 E and from 42 N to 65 N. Further 3 nested grids better resolve the North Sea (with 6.4km), southern North Sea (with 3.2km) and the German Bight (with 1.6km). Model data from grid 1 and grid 4 are available in this data bank. Please contact the authors for data from grid 2 and grid 3. Time supplement procedure: data over period 2013-2015 appended 04-05-2016
Simulated 2D residual velocity fields in the inner German Bight were subjected to Principal Component Analysis (PCA). Residual currents were obtained from coastDat2 barotropic 2D simulations with the hydrodynamic model TRIM-NP V2.1.22 in barotropic 2D mode on a Cartesian grid (1.6km spatial resolution) stored on an hourly basis for the years 1948 - 2012 (doi:10.1594/WDCC/coastDat-2_TRIM-NP-2d) and later extended until August 2015. The present analysis refers to the period Jan 1958 - Aug 2015. The spatial domain considered is the region to the east of 6 degrees east and to the south of 55.6 degrees north. All grid nodes with a bathymetry of less than 10m were excluded. Residual velocities were calculated in two different ways: 1.) as 25h means, 2.) as monthly means. Both types of residual current data are available from * RESIDUAL_CURRENTS_195801_201508 The directory contains sub-directories for years and months. Daily residual currents for the 13th of September 1974, for instance, are stored in * RESIDUAL_CURRENTS_195801_201508/YEAR_1974/MONTH_09/TRIM2D_1974_09_13_means.nc while monthly mean residual currents for September 1974 are stored in: * RESIDUAL_CURRENTS_195801_201508/YEAR_1974/TRIM2D_1974_09_means.nc All current fields provided were interpolated from the original Cartesian model grid to a more convenient regular geographical grid (116x76 nodes). Mean residual currents are stored in: * mean_residual_currents.nc This data set contains residual velocities both on original Cartesian grid nodes and interpolated to the geographical grid. An example plot is provided: * mean_residual_currents.png For PCA, two residual velocity components from each of 12133 Cartesian grid nodes were combined into one data vector (length 2x12133), referring to 21061 daily or 692 monthly time levels. Results of two independent PCAs for either daily or monthly mean fields are stored in: * PCA_daily_residual_currents.nc * PCA_monthly_residual_currents.nc Files contain three leading Principal Components (PCs) and corresponding Emipirical Orthogonal Functions (EOFs). Again EOFs were also interpolated to a regular geographical grid. PC time series are also stored in plain ASCII format: * PCs_daily.txt * PCs_monthly.txt For monthly fields the number N of variables (N=2x12133) is much larger than the number T of time levels (T=692). Therefore, to reduce computational demands, the roles of time and space were formally interchanged. Having conducted the PCA the EOFs were then transformed back to the original spatial coordinates (cf. Section 12.2.6 in von Storch and Zwiers (1999), Statistical Analysis in Climate Research, Cambridge University Press). A much larger number of time levels made even this approach prohibitive for the full set of daily data. Therefore, PCAs were performed for six sub-periods (1958-1965, 1966-1975, 1976-1985, 1986-1995, 1996-2005, 2006-2015(Aug)) independently. EOFs obtained from these six sub-periods were then averaged to obtain EOFs representative for the whole period. Corresponding PCs were calculated by projecting daily fields onto these average EOFs. IMPORTANT: In contrast with PCA of monthly data, the PCA of daily data INVOLVES SOME APPROXIMATIONS! EOFs on the original nodes were normalized to have unit lengths. The following figures, * daily_EOF1.png * daily_EOF2.png * daily_EOF3.png show the first three EOFs obtained from daily data, assuming that corresponding PCs have the value of one standard deviation. The following two plots, * monthly_EOF1.png * monthly_EOF2.png show the leading EOFs for monthly mean data. EOF3 is omitted as it represents just a very small percentage of overall variance (1.7%).