# High resolution Austrian Re-analysis ensemble with AROME (ARA)

## Overview

This dataset high resolution Austrian re-analysis ensemble data from the Geosphere Austria, AROME model. Reanalysis combines model data with observations across a historical period to create a consistent, best-estimate dataset. This ensemble contains 11 members / 2012-01-01 to 2022-12-31 / 2.5 km equidistant grid centred over Austrian Alps. Over 50, 2D and 10, 3D parameters on height, pressure and model levels are available. Model level data on all 90 models levels is only available for control member (MEM_00). Full list of all available parameters can be provided upon request. This ensemble provides a quantification of uncertainty in the reanalysis through multiple realizations (members).

## How to cite this dataset

If you use this dataset in a publication, please cite it as follows:

Awan, N. K., Wittmann, C., Wastl, C., and Meier, F.: High resolution regional re-analysis ensemble for Austria, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20433, https://doi.org/10.5194/egusphere-egu24-20433, 2024. 


##License: 

This dataset is made available under the Creative Commons Attribution 4.0 International (CC-BY-4.0).

You are free:
- To share: copy and redistribute the material in any medium or format for any purpose, even commercially
- To adapt: remix, transform, and build upon the material for any purpose, even commercially

Under the following conditions:
- Attribution: You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. 

For the full license text, see: https://creativecommons.org/licenses/by/4.0/legalcode.en

## Dataset Details

* Reanalysis System:  AROME cy43t2
* Spatial Coverage:   Greater Alpine Region GAR
* Spatial Resolution: 2.5 km horizontal resolution, netcdf files for each vertical levels i.e. 90 model levels[only for MEM_00], 18-23 pressure levels, 2-7 geometric height above ground levels, height above sea-level, mean sea-level, surface
* Temporal Coverage:  2012-01-01 to 2021-12-31
* Temporal Resolution: 1-hourly
* Ensemble Generation Method: 10-member ensemble generated by perturbing initial conditions, observations and model physics (details in Wastl .et. al)
* Assimilation Method: 3D-Var data assimilation system

## File Structure and Naming Convention

The data is organized by date, forecast run (analysis cycle), and ensemble member number.

The top-level directory structure is:

yyyymmdd/
└── run/
├── MEM_00/
│ └── [model output files for member 0]
├── MEM_01/
│ └── [model output files for member 1]
...
└── MEM_10/
└── [model output files for member 10]


*   `yyyymmdd`: The date of the model analysis/run (e.g., `20231001` for October 1, 2023).
*   `run`: The model run LBC and assimilation update freq/cycle identifier (e.g., `00`, `03`, `06` ... `21` for 00UTC, 03UTC, etc. runs).
*   `MEM_xx`: Directory for each ensemble member, where `xxx` ranges from `000` to `010` (11 members total).

### File Names

For every time step we have 5-6 NetCDF files depending on vertical coordinates i.e. 90 model levels[only for MEM_00], 18-23 pressure levels, 2-7 geometric height above ground levels, height above sea-level, mean sea-level, and surface level.

Individual files within the member directories follow this convention:
`ARA[EnsembleMember]_00[LeadTime]_00_[LevelType]_cf.nc`

## File List
ARA00_0000_00_hybrid_cf.nc [only for MEM_00]
ARA00_0000_00_pressure_cf.nc
ARA00_0000_00_hagl_cf.nc
ARA00_0000_00_hasl_cf.nc
ARA00_0000_00_surface_cf.nc
ARA00_0000_00_meansea_cf.nc

Example:
`ARA04_0001_00_pressure_cf.nc`

*   `20211001`: Date
*   `00`: Run (00UTC)
*   `MEM_00`: Ensemble member 00
*   `pressure`: Vertical coordinate pressure in hPa

## Data Format

*   Format: [NetCDF] (CF-Compliant)
*   Dimensions: Typically `time`, `latitude`, `longitude`, `lev` (3D)
*   Dimensions: Typically `time`, `latitude`, `longitude` (2D)
*   Grid:  Regular latitude-longitude grid

## Variable List

The following primary variables are included in this dataset:
_____________________________________________________________________

*     ****    ARA00_0000_00_hybrid_cf.nc      ****
_____________________________________________________________________
| Short Name | Long Name | Units | Description |
| `longitude` | longitude | degrees_east | longitude |
| `latitude` | latitude | degrees_north | latitude |
| `level` | model_level_number | N/A | model_level_number |
| `time` | time | hours since 1900-01-01 00:00:00.0 | time |
| `u` | U component of wind | m s**-1 | U component of wind |
| `v` | V component of wind | m s**-1 | V component of wind |
| `t` | Temperature | K | Temperature |
| `q` | Specific humidity | kg kg**-1 | Specific humidity |
| `lwc` | Liquid water content | kg kg**-1 | Liquid water content |
| `swc` | Solid water content | kg kg**-1 | Solid water content |
| `z` | Geopotential | m**2 s**-2 | Geopotential |
| `pres` | Pressure | Pa | Pressure |
_____________________________________________________________________

*     ****    ARA00_0000_00_pressure_cf.nc    ****
_____________________________________________________________________
| Short Name | Long Name | Units | Description |
| `longitude` | longitude | degrees_east | longitude |
| `latitude` | latitude | degrees_north | latitude |
| `level` | pressure_level | millibars | pressure_level |
| `time` | time | hours since 1900-01-01 00:00:00.0 | time |
| `u` | U component of wind | m s**-1 | U component of wind |
| `v` | V component of wind | m s**-1 | V component of wind |
| `t` | Temperature | K | Temperature |
| `q` | Specific humidity | kg kg**-1 | Specific humidity |
| `lwc` | Liquid water content | kg kg**-1 | Liquid water content |
| `swc` | Solid water content | kg kg**-1 | Solid water content |
| `snowc` | Snow content | kg kg**-1 | Snow content |
| `rainc` | Rain content | kg kg**-1 | Rain content |
| `grplc` | Graupel 3D | kg kg**-1 | Graupel 3D |
| `tke` | TKE | m**2 s**-2 | TKE |
| `z` | Geopotential | m**2 s**-2 | Geopotential |
| `rh` | Relative Humidity | 0-1 | Relative Humidity |
| `w` | Vertical velocity | Pa s**-1 | Vertical velocity |
_____________________________________________________________________

*     ****    ARA00_0000_00_hagl_cf.nc        ****
_____________________________________________________________________
| Short Name | Long Name | Units | Description |
| `time` | time | days since 1900-01-01 | time |
| `lon` | longitude | degrees_east | longitude |
| `lat` | latitude | degrees_north | latitude |
| `height` | height above surface | m | height above surface |
| `height_2` | height above surface | m | height above surface |
| `height_3` | height above surface | m | height above surface |
| `height_4` | height above surface | m | height above surface |
| `height_5` | height above surface | m | height above surface |
| `height_6` | height above surface | m | height above surface |
| `height_7` | height above surface | m | height above surface |
| `tas` | Near-surface air temperature | K | Near-surface air temperature |
| `rh` | Relative humidity | % | Relative humidity |
| `u` | Eastward wind component | m s^-1 | Eastward wind component |
| `v` | Northward wind component | m s^-1 | Northward wind component |
| `tmax` | Daily maximum temperature | K | Daily maximum temperature |
| `tmin` | Daily minimum temperature | K | Daily minimum temperature |
| `lwc` | Liquid water content | kg kg^-1 | Liquid water content |
| `dbz` | Radar reflectivity | dBZ | Radar reflectivity |
| `ps` | Surface pressure | Pa | Surface pressure |
| `vis` | Visibility | m | Visibility |
_____________________________________________________________________

*     ****    ARA00_0000_00_hasl_cf.nc        ****
_____________________________________________________________________
| Short Name | Long Name | Units | Description |
| `time` | time | days since 1900-01-01 | time |
| `lon` | longitude | degrees_east | longitude |
| `lat` | latitude | degrees_north | latitude |
| `alt` | height_above_mean_sea_level | m | height_above_mean_sea_level |
| `alt_2` | height_above_mean_sea_level | m | height_above_mean_sea_level |
| `htop_stratus` | Cloud top altitude of stratus clouds | m | Cloud top altitude of stratus clouds |
| `hbas_stratus` | Cloud base altitude of stratus clouds | m | Cloud base altitude of stratus clouds |
| `tas` | Near-surface air temperature | K | Near-surface air temperature |
_____________________________________________________________________

*     ****    ARA00_0000_00_meansea_cf.nc     ****
_____________________________________________________________________
| Short Name | Long Name | Units | Description |
| `longitude` | longitude | degrees_east | longitude |
| `latitude` | latitude | degrees_north | latitude |
| `time` | time | hours since 1900-01-01 00:00:00.0 | time |
| `msl` | Mean sea level pressure | Pa | Mean sea level pressure |
_____________________________________________________________________

*     ****    ARA00_0000_00_surface_cf.nc     ****
_____________________________________________________________________
| Short Name | Long Name | Units | Description |
| `longitude` | longitude | degrees_east | longitude |
| `latitude` | latitude | degrees_north | latitude |
| `time` | time | hours since 1900-01-01 00:00:00.0 | time |
| `t` | Temperature | K | Temperature |
| `ssnowa` | Surface snow amount | kg m**-2 | Surface snow amount |
| `sundur` | Sunshine duration | s | Sunshine duration |
| `lsic` | Low Stratus counter |   | Low Stratus counter |
| `insn` | Industrial snow |   | Industrial snow |
| `rain` | Rainfall | kg m**-2 | Rainfall |
| `snow` | Snowfall | kg m**-2 | Snowfall |
| `grpl` | Graupel | kg m**-2 | Graupel |
| `ssr` | Net short-wave radiation flux (surface) | W m**-2 | Net short-wave radiation flux (surface) |
| `str` | Net long-wave radiation flux (surface) | W m**-2 | Net long-wave radiation flux (surface) |
| `grad` | Surface global radiation | Ws m**-2 | Surface global radiation |
 `stri` | Surface thermal radiation at init | Ws m**-2 | Surface thermal radiation at init |
| `csnsr` | clear sky net solar radiance | Ws m**-2 | clear sky net solar radiance |
| `strc` | clear sky net thermal radiation | Ws m**-2 | clear sky net thermal radiation |
| `ligden` | Lightning density | # km**-2 | Lightning density |
| `precdur` | Precipitation duration | s | Precipitation duration |
| `tcc` | Total cloud cover | 0-1 | Total cloud cover |
| `hcc` | High cloud cover | 0-1 | High cloud cover |
| `mcc` | Medium cloud cover | 0-1 | Medium cloud cover |
| `lcc` | Low cloud cover | 0-1 | Low cloud cover |
| `ugust` | u gust | m s**-1 | u gust |
| `vgust` | v gust | m s**-1 | v gust |
| `blh` | Mixed layer depth | m | Mixed layer depth |
| `dhail` | Diagnostic hail | kg m**-2 | Diagnostic hail |
| `mcn` | MOCON | kg kg**-1 s**-1 | MOCON |
| `ptype` | precip type |   | precip type |
| `ptype_sev` | precip type severe |   | precip type severe |
| `zsurf` | Surface Geopotential | m**2 s**-2 | Surface Geopotential |
| `dlsh` | Deep layer shear | m s**-1 | Deep layer shear |
| `llsh` | Low level shear | m s**-1 | Low level shear |
| `hlcy` | Storm relative helicity | J kg**-1 | Storm relative helicity |
| `uphl` | Updraft helicity | J kg**-1 | Updraft helicity |
| `pwat` | Total precipitable water | kg m**-2 | Total precipitable water |
| `sp` | Surface pressure | Pa | Surface pressure |
| `Tw15` | Tw=1.5 isotherm | m | Tw=1.5 isotherm |
| `cape` | CAPE | m**2 s**-2 | CAPE |
| `cin` | CIN | m**2 s**-2 | CIN |
| `lcl` | Lifting condensation level | gpm | Lifting condensation level |
| `lfc` | Level of free convection | gpm | Level of free convection |
| `equlev` | Equilibrium level | gpm | Equilibrium level |
| `snli` | Snowfall line | m | Snowfall line |
| `sai` | Showalter Index |   | Showalter Index |
| `tp` | Total Precipitation | kg m**-2 | Total Precipitation |
| `ct` | Convective Temperature | K | Convective Temperature |
| `gust10m` | 10 m surface wind gust | m s**-1 | 10 m surface wind gust |
| `orog` | Orography | m | Orography |
_____________________________________________________________________


## Ensemble Members

This dataset consists of an 11-member ensemble.
*   MEM_00              : The unperturbed control member.
*   MEM_01 ..... MEM_010: Perturbed ensemble members.

The spread across the ensemble can be used to estimate probabilistic uncertainty in the reanalysis.

## Quality Notes & Known Issues

*   Known issues will be added here. 
*   Progress of data transfer and missing file list can be shared upon request.
*   This dataset is not suitable for investigating short duration extreme convective precipitation events. User's are advised to take into account the spatial and temporal shifts which are present in the hourly precipitation.
*   Please see the accompanying document `Quality_Report.pdf` for a detailed discussion of biases and uncertainties.

## Contact

For reporting issues concerns, or questions regarding this dataset, please contact:
Dr. Nauman Khurshid Awan (Geosphere Austria, CU NWP)
nauman.awan@geosphere.at

## Acknowledgments

This reanalysis was produced by Geosphere Austria Gmbh within the framework of ARA project. This development and production of this regional reanalysis was funded by FFG, ASAP-17, under grant 885351.

## References

WastlC.,Y.Wang,A.Atencia,F.Weidle,C.Wittmann,C.Zingerle,E.Keresturi,2021:CLAEF:Convection-permittingLimited-AreaEnsembleForecastingsystem.QuarterlyJournaloftheRoyalMeteorologicalSociety,147:1431-1451,https://doi.org/10.1002/qj.3986
Wastl,C.,Wang,Y.,Atencia,A.andWittmann,C.(2019a)Inde-pendentperturbationsforphysicsparameterizationtendenciesinaconvectionpermittingensemble.GeoscientificModelDevelopment,12,261–273.https://doi.org/10.5194/gmd-12-261-2019.
Wastl, C., Wang, Y., Atencia, A. and Wittmann, C. (2019b) A hybrid stochastically perturbed parametrization scheme in a convection permitting ensemble. Monthly Weather Review, 147, 2217–2230.https://doi.org/10.1175/MWR-D-18-0415.1