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Regionally refined high-resolution and mass-consistent AH+O de-aliasing coefficients for GRACE/-FO

The dataset (Mielke et al, 2023) consists of daily ASCII-files, each containing the spherical harmonic coefficients (SHCs) for atmosphere, hydrology, and ocean bottom pressure. The files that include the AH+O coefficients are provided in the AOD format of the GFZ with the naming convention TYPE_YYYY-MM-DD_X_01.asc and contain header information (30 lines) and four columns with degree (n) order (m) and Stokes coefficients cnm and snm. Coefficients in each file are split up into different subsets, each corresponding to a subdaily time step (i.e., a daily file with 3-hour temporal resolution is split up into 8 subsets). The entire dataset is organized following the folder structure /TYPE/NEST/coeff_aodFormat_XXX/. We provide regional refined (nested), coarse grained (nested, but with a lower resolution version of the regional model), or global model solutions of SHCs for each datatype. Some datasets are available in different spectral resolutions, with d/o up to 179, 180, or 360. In this release all AH+O coefficients have a temporal resolution of 3 hours, except the non-regional refined atmospheric solution, which is given 6-hourly. Currently, the whole data set is provided for June 2007 and some components for the whole year 2007. Additional months and years will be added with newer versions of the dataset or can be provided by the authors on request. For the atmospheric and hydrological background model, regional models with high spatial and temporal resolution are nested into global models: Therefore, global and regional models must be resampled and interpolated on the same regular grid with equivalent time epochs. For the nesting, the global model is interpolated on the same grid resolution as the regional model. Grid points of the global model are than replaced with the data of the regional model of the CORDEX-EU region. A Gaussian filter is applied in a transition zone with a width of 7.5° to reduce an edge effect (Gibbs effect) between the two combined models.

AOe07 Variance-Covariance-Matrix

The Atmosphere and Ocean non-tidal De-aliasing Level-1B (AOD1B) product is widely used in satellite gravimetry to correct for transient effects of atmosphere-ocean mass variability that would otherwise alias into monthly-mean global gravity fields. The most recent release is based on the global ERA5 reanalysis and ECMWF operational data together with simulations from the general ocean circulation model MPIOM consistently forced with fields of the same atmospheric data-set. As background models are inevitably imperfect, residual errors due to aliasing remain. Accounting for the uncertainties of the background model data has, however, proven to be a useful approach to mitigate the impact of residual aliasing. In light of the changes made in the new release of AOD1B, previous uncertainty assessments are deemed too pessimistic and have been revised in the new time-series of true errors: AOe07. One possible way to include the uncertainty information of background models in gravity field estimation or simulation studies is through the computation and application of a variance-covariance matrix that describes the spatio-temporal error characteristics of the background model. The AOe07 variance-covariance-matrix provides this information through (1) a fully populated matrix up to degree and order 40 as well as (2) a diagonal matrix up to degree and order 180.

Atmosphere and Ocean Non-Tidal Dealiasing Level-1B (AOD1B) Product RL07

The Atmosphere and Ocean De-Aliasing Level-1B (AOD1B) Product provides a priori information about temporal variations in the Earth's gravity field caused by global mass variability in atmosphere and ocean.'It is based on analysis and forecast data of the operational high-resolution global numerical weather prediction (NWP) model from the European Centre for Medium-Range Weather Forecasts (ECMWF) such as ERA5 and ocean bottom pressure from an unconstrained simulation with a global ocean general circulation model that is consistently forced with ECMWF atmospheric data.

Simulation data from GAIA (Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy)

This dataset comprises numerical outputs from the whole atmospheric model GAIA (=Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy) and associated simulations presented in the article "Whole atmosphere model simulations of ultra-fast Kelvin wave effects in the ionosphere and thermosphere" (Yamazaki et al., 2020).GAIA is a numerical model of the Earth’s whole atmosphere (e.g., Jin et al., 2011; Miyoshi et al., 2011). The model consists of mathematical equations appropriate for various physical and chemical processes in the troposphere, stratosphere, mesosphere, and thermosphere. The neutral atmosphere model (Miyoshi & Fujiwara, 2003) is coupled with an ionospheric model (Shinagawa, 2011) and electrodynamics model (Jin et al., 2008). The lower layers of the model below 30 km are constrained by meteorological reanalysis products by the Japan Meteorological Agency (Onogi et al., 2007; Kobayashi, et al., 2015).The model was run for the following three time intervals:1. 15 August 2010 - 15 October 20102. 01 August 2011 - 30 September 20113. 01 December 2012 - 31 January 2013The simulation outputs can be found in GAIA/2010, GAIA/2011, and GAIA/2013, respectively. In each directory, the model data are stored in a MATLAB format (.mat).List of model outputs:GZ: "Geopotential height" in [m] as a function of LONGITUDE [˚], LATITUDE [˚], PRESSURE, and TIMEGU: "Zonal wind" in [m/s] as a function of LONGITUDE, LATITUDE, PRESSURE, and TIME (positive eastward)GV: "Meridional wind" in [m/s] as a function of LONGITUDE, LATITUDE, PRESSURE, and TIME (positive northward)GT: "Temperature" in [K] as a function of LONGITUDE, LATITUDE, PRESSURE, and TIMEEEF: "Equatorial zonal electric field" in [V/m] as a function of LONGITUDE and TIME.TEC: "Total electron content" in [TECU] as a function of LONGITUDE, LATITUDE, and TIMEPRESSURE is given at: 10^2, 10^1, 10^0, 10^(-1), 10^(-2), 10^(-3), 10^(-4), 10^(-5), 10^(-6), 10^(-7), 10^(-8) [hPa]For the time period #1, additional controlled simulations "LARGE_WAVES" and "NO_UFKW" were run. See Yamazaki et al. (2020) for details of these runs. The simulation outputs can be found in LARGE_WAVES/2011 and NO_UFKW/2011, respectively.

Simulation data from GAIA (Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy) for the September 2019 sudden stratospheric warming event

This dataset comprises numerical outputs from the whole atmospheric model GAIA (=Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy) and associated simulations (EXP1, EXP2, and EXP3) presented in the article "Excitation mechanism of ionospheric 6-day oscillation during the 2019 September sudden stratospheric warming event" (Miyoshi and Yamazaki, 2020). Briefly, GAIA is a numerical model of the Earth’s whole atmosphere (e.g., Jin et al., 2011; Miyoshi et al., 2011, 2012). The model consists of mathematical equations that represent various physical and chemical processes in the troposphere, stratosphere, mesosphere, and thermosphere. The neutral atmosphere model (Miyoshi & Fujiwara, 2003) is coupled with an ionospheric model (Shinagawa, 2011) and electrodynamics model (Jin et al., 2008). The lower layers of the model below 40 km are constrained by meteorological reanalysis products by the Japan Meteorological Agency (Kobayashi, et al., 2015). The model was run for the period 1 September-10 October 2019, when there was a sudden stratospheric warming in the Antarctic region (Yamazaki et al., 2020). The GAIA simulation outputs can be found in the directory 'gaia', while the numerical outputs from the controlled simulations EXP1, EXP2, and EXP3 can be found in the directories 'exp1', 'exp2', and 'exp3', respectively. The model data for the temperature, zonal wind, meridional wind, and geopotential heigh are stored separately for each day in the NetCDF format. 'gt', 'gu', 'gv', and 'gz' in file name indicate the temperature, zonal wind, meridional wind, and geopotential heigh, respectively. For instance, the file 'gv20190915gcm.nc' contains the meridional wind data for 15 September 2019. The model data for the eastward current intensity, eastward electric field, and total electron content can be found as text files, namely, 'East_current_gaia.data', 'East_efield_gaia.data', and 'tec_gaia.data'.

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