ECOMIP

Welcome to ECOMIP

If you would like to participate in ECOMIP, or if you wish to receive related information, please submit this form, or contact the coordinators (Masaki Satoh, Robin Hogan).  

Experimental protocol

Please refer to this info for the latest protocol, or see below:

Simulations

Two types of simulations are envisaged for the ORCESTRA period from 9 August to 29 September 2024.

1. 2-day simulation: For selected cases listed below, simulations should be initialized at 00 UTC one day prior to the case date. Comparisons with EarthCARE observations and across models will be conducted using data from the second day of each forecast. Operational NWP centers may alternatively provide their standard operational forecasts for this period.

2. A free-running simulation: A continuous simulation initialized at 00 UTC on 1 August 2024 and run through the end of September 2024.

Strategy of the experiments

• Phase 1 – Case studies (2-day simulations), submission by the end of 2025

Target specific events aligned with EarthCARE and ORCESTRA observations.

Mandatory case: 3 Sep 2024 for convection; 13 Aug 2024 for aerosol

Optional cases: additional events selected based on participant interest.

• Phase 2 – Free run, submission in 2026

Continuous simulations of at least two months, and additional optional cases (continued), or repear of the mandatory case.

• Phase 3 – Constrained free run in 2026 or afterwards

Free runs with prescribed terminal velocity and other improved settings derived from EarthCARE/ORCESTRA insights.

A common configuration is applied across all participating models.

Cases

The 18 dates with HALO aircraft flights are listed here. 

Candidate cases in terms of deep convection are the following:

• 18 August

• 22 August

• 27 August

• 3 September: a golden case in terms of observations from EarthCARE, the HALO aircraft and the Meteor ship

• 19 September

• 21 September

Candidates for aerosol transport

• 11 August

• 13 August: Best case for aerosol

• 25 August

• 27 Augsut

• 29 August

• 31 August

• 3 September

Note that the simulations themselves should be initialized at the beginning of the previous day.

Note also that no CPR data were taken on 29 August and 22 September, and the CPR collection was incomplete for 28 and 30 August, and 2, 3, 12, 20, 21 and 23 September.

Initial data

Ideally the simulations would be initialized from ECMWF's operational 9-km analyses, which may be obtained by making an archive order here. Note that research access is free of charge - if this is questioned, please contact Robin Hogan. A second option is to initialize from ECMWF's ERA5 reanalysis, which is also freely available. Generally this is an inferior option as it uses an older version of the model and is at lower resolution. If your model has its own analysis system or is normally initialized from different analysis dataset to the above, then if easier, this may be used instead.

For the case 3 Sep. 2025: IFS operational data provided by Robin Hogan:

https://aux.ecmwf.int/ecpds/home/earthcare_public/earthcare-orcestra-mip/ifs_od-0001_orcestra_domain/

https://aux.ecmwf.int/ecpds/home/earthcare_public/earthcare-orcestra-mip/ifs_od-0001_global_analyses/

Output data

Since high resolution simulations are computationally intensive, some models may not be able to simulate the entire period, in which case the dates corresponding to the most interesting ORCESTRA case studies should be prioritized. 

The following output datasets are envisaged from each model:

1. Three-dimensional model fields extracted over the Tropical Atlantic domain of ORCESTRA, bounded in longitude between 64°W and 8°W, and latitude between 4°S and 24°N. Ideally the output frequency would be 30 minutes for the 3D fields and 10 minutes for the 1D fields, but it is recognised that some models (and certainly archives of operational forecasts) are tricky to archive more frequently than every hour. Focus should be placed on the most interesting ORCESTRA case studies listed above, but storing the entire 24 hour period starting at 00 UTC. Output from ICON-MPI at 1.25 km for this region can be visualized here.

2. Optionally, the full global dataset could be shared, which would provide a dataset similar to previous global storm-resolving model intercomparisons such as DYAMOND. Such a dataset is particularly requested by JAXA and would benefit the satellite community, who could use it for future applications of satellite projects.

3. Model slices corresponding to each EarthCARE "frame", which is an eighth of an orbit. The Mini JSG files here define the times and locations of each frame in the ECOMIP period. The model data should be taken from the closest archiving time of the simulation and interpolated to the longitude and latitude grid from the JSG file, which is around 1-km resolution. The models own levels should be used in the vertical. One file per frame should be produced. 

Because the location and timing of cloud systems may differ slightly between observations and model simulations, it may be necessary to shift the locations of the model data slices when comparing them with the EarthCARE data. Additionally, a larger sample size is necessary to assess the robustness of the model's results. Therefore, we recommend Option 1 or 2 rather than Option 3. 

The output fields should ideally include:

• 3D data

Temperature, pressure, vertical winds, mixing ratio of water vapor and all hydrometeors (cloud ice, cloud water, rain, snow, graupel); horizontal wind components (u, v)

For a double-moment microphysics scheme: the number concentration of each hydrometeor  

• 2D data

Surface temperature, horizontal winds at 10m height, sea level pressure; surface elevation (topography), land use data, soil moisture; OLR, OSR, OLR_clearsky, OSR_clearsky, insolated solar radiation at TOA, precipitation (snapshot & 30min-average), IWP, LWP, precipitable 

The above data includes both input data for a satellite simulator and those for diagnosis. Details of cloud microphysics data are required for a specific cloud microphysics scheme. If applicable, also store cloud fraction, precipitation fraction, and convective mass flux. For rain rate, split into convective and large-scale, if available.

Meteorological variables on model levels: height above the surface. 

• Aerosol transport case

mass and number concentration of black carbon/organic carbon, dust, sulfate, sea salts, and so on; speciated mass concentration in ug m-3 (for sulfate mass of S only)  lumping aerosol bins/modes as needed; 3D extinction (at 550nm (MODIS) and 355nm (EarthCARE)); 3D extinction due to absorption (extinction x (1-SSA))  (at 550nm (MODIS) and 355nm (EarthCARE)); CCN at several supersaturations (need to check which supersaturations were CCNs measured at during ORCESTRA); Cloud hydrometeors and 3D winds at aerosol output intervals; Desireable: hydrometor fall speeds and/or simulated EarthCARE reflectivity weighted crystal vertical velocity at same intervals (harmonise with non-aerosol protocol); Additional output should include key aerosol measurements from ORCESTRA (check!)

• Data frequency and format

Two-day simulations: Output all data at 30-minute intervals for the second day (e.g., 49 snapshot times).

Optional: Provide 5-minute data only for 2-D fields of OLR, OSR, and precipitation (both snapshots and 5-minute averages).

2-month simulations: TBD.

Grid and Vertical Levels:

Latitude–longitude grids and standard vertical levels are the preferred format. Optionally, data may also be provided on the original model grid and native model levels. HEALPix-format output is encouraged, but not required at this stage.

• Microphysics Scheme information

Number and definitions of hydrometeor categories (density, shape, etc); size distribution; mass-dimension relationship; terminal velocity with a diameter

• Output format

The output format should be netCDF (either netCDF3 or netCDF4/HDF5). 

While we are not prescriptive on variable names, dimension orders etc, some sample netCDF files from ECMWF's Integrated Forecasting System may be found here.

A README file must be provided to describe the data format and relevant model details.

• Remarks on data for simulator input (two-moment bulk scheme)

When using the simulator input with the two-moment bulk microphysics scheme, please be aware of the following critical points:

Lat–Lon Conversion Method
Use the nearest-neighbor method for latitude–longitude conversion.
Interpolation methods (e.g., bilinear interpolation) can introduce inconsistencies between mass and number concentrations at cloud edges. This may result in unrealistic radar reflectivity, particularly near cloud boundaries.

Vertical Layer Settings
Use the model’s native vertical layers rather than interpolated pressure levels.  Vertical interpolation can distort cloud-top and cloud-base structures, leading to inaccurate representations of cloud profiles.

Data submission

JAXA will provide a data server for archiving the model output. Due to security requirements, data cannot be uploaded directly to the JAXA server. Instead, an intermediate server at The University of Tokyo is available for data transfer.

Please contact Takuji Kubota (JAXA; kubota.takuji@jaxa.jp) and Masaki Satoh (The University of Tokyo) for instructions on data submission.

Data analysis

Once the model data are shared, participants may intercompare models and evaluate using EarthCARE as they see fit, although care needs to be taken to ensure the correct microphysical interpretation of the model fields, and indeed to the strengths and weaknesses of the various EarthCARE products. Generally speaking we may compare model fields against retrievals of the same quantities, as illustrated in the preliminary model evaluation shown here, or compare in observation space by "forward modelling" the observations from model fields. 

ECOMIP data archive

To collect ECOMIP model data and share with ECOMIP researchers in a password-protected manner, JAXA has prepared a server for ECOMIP. The ftp/sftp server for ECOMIP has already been in operation under “ftp.eorc.jaxa.jp” (UID: ecomip) and users can download the data from the server.​

Satellite simulator analysis

An important part of ECOMIP will need to be an intercomparison of the various satellite simulators in order to understand their differences. This is challenging as they need to make assumptions about the particle size distributions and particle shapes and densities, as well as sub-grid cloud structure. These assumptions are typically different in each model. Satellite simulators used by the individual ECOMIP participants are:

• The Joint Simulator for Satellite Sensors (J-Sim): Developed by JAXA for the EarthCARE mission

• PAMTRA: Passive and active microwave radiative transfer tool

• ECSIM: used to simulate EarthCARE observations for the pre-launch special issue of AMT

• RTTOV: used for simulating microwave, infrared and most recently solar radiances for data assimilation, used by European NWP centres. A radar simulator is under development.

• COSP: used to simulate radar, lidar and radiometer data targeted at low-resolution climate models used in IPCC.

• JEDI/CRTM: used to simulate radiances for data assimilation.

• ZMVar: used by ECMWF for assimilating radar and lidar backscatter profiles.

• The Spaceborne Radar Simulator (SR-SIM)

Researchers who are not familiar with satellite simulators may instead analyze model fields in physical space and compare them with the corresponding retrieved quantities, such as ice and liquid water content. JAXA plans to apply J-Sim to the updated model variables.