# \#conversion **URL:** https://forum.ecmwf.int/tag/conversion/85.md [Latest](https://forum.ecmwf.int/latest.md) · [Categories](https://forum.ecmwf.int/categories.md) · [Tags](https://forum.ecmwf.int/tags.md) --- ## [About snowfall and snowmelt, how to caculate total monthly snowfall and snowmelt?](https://forum.ecmwf.int/t/about-snowfall-and-snowmelt-how-to-caculate-total-monthly-snowfall-and-snowmelt/1637)
**Author:** [@Dango\_Zhang](https://forum.ecmwf.int/u/Dango_Zhang)\ **Replies:** 4\ **Last updated:** [27 July 2026 11:19 UTC](https://forum.ecmwf.int/t/about-snowfall-and-snowmelt-how-to-caculate-total-monthly-snowfall-and-snowmelt/1637 "2026-07-27T11:19:44Z")
Dear all, I am using Snowfall and Snowmelt of ERA5-Land. First of all, I would like to ask, the document (ERA5-Land: data documentation, ERA5-Land: data documentation-Copernicus Knowledge Base-ECMWF Confluence Wiki) sa… --- ## [Geopotential height on model levels](https://forum.ecmwf.int/t/geopotential-height-on-model-levels/1439)
**Author:** [@Amelie\_Mayer](https://forum.ecmwf.int/u/Amelie_Mayer)\ **Replies:** 7\ **Last updated:** [8 April 2026 13:52 UTC](https://forum.ecmwf.int/t/geopotential-height-on-model-levels/1439 "2026-04-08T13:52:32Z")
Hi guys, I used that nice script Compute geopotential on model levels to compute the geopotential height on model levels of some ERA5 data. In doing so, I came across some strange behavior: At those locations on Earth w… --- ## [Using CAMS data from global atmospheric composition forecasts as IC and BC in WRF-Chem. Trouble Converting GRIB to NetCDF](https://forum.ecmwf.int/t/using-cams-data-from-global-atmospheric-composition-forecasts-as-ic-and-bc-in-wrf-chem-trouble-converting-grib-to-netcdf/1135)
**Author:** [@Maria\_Francisca\_Card](https://forum.ecmwf.int/u/Maria_Francisca_Card)\ **Replies:** 3\ **Last updated:** [26 November 2025 15:21 UTC](https://forum.ecmwf.int/t/using-cams-data-from-global-atmospheric-composition-forecasts-as-ic-and-bc-in-wrf-chem-trouble-converting-grib-to-netcdf/1135 "2025-11-26T15:21:40Z")
Dear all, I downloaded CAMS data from global atmospheric composition forecast for a simulation with WRF-Chem following the instructions How to run the WRF-Chem model using CAMS data as initial and boundary conditions (B… --- ## [Convert mass mixing ratio (MMR) to mass concentration or to volume mixing ratio (VMR)](https://forum.ecmwf.int/t/convert-mass-mixing-ratio-mmr-to-mass-concentration-or-to-volume-mixing-ratio-vmr/1253)
**Author:** [@Michela](https://forum.ecmwf.int/u/Michela)\ **Replies:** 8\ **Last updated:** [5 March 2025 13:00 UTC](https://forum.ecmwf.int/t/convert-mass-mixing-ratio-mmr-to-mass-concentration-or-to-volume-mixing-ratio-vmr/1253 "2025-03-05T13:00:03Z")
How do I convert MMR to VMR? --- ## [Surface Radiation Parameters: Joule/m^2 to Watt/m^2](https://forum.ecmwf.int/t/surface-radiation-parameters-joule-m-2-to-watt-m-2/1588)
**Author:** [@Michela](https://forum.ecmwf.int/u/Michela)\ **Replies:** 10\ **Last updated:** [17 January 2025 15:35 UTC](https://forum.ecmwf.int/t/surface-radiation-parameters-joule-m-2-to-watt-m-2/1588 "2025-01-17T15:35:29Z")
Radiation parameters for surface and single levels, as Surface Solar Radiation, are accumulated parameters. Data is Joule per square metre, accumulated over the respective period. To get Watts per square metre, the accu… --- ## [Convert ERA5 pressure levels data to model levels with hybrid coordinate](https://forum.ecmwf.int/t/convert-era5-pressure-levels-data-to-model-levels-with-hybrid-coordinate/1281)
**Author:** [@Delei\_Li](https://forum.ecmwf.int/u/Delei_Li)\ **Replies:** 0\ **Last updated:** [13 September 2023 01:27 UTC](https://forum.ecmwf.int/t/convert-era5-pressure-levels-data-to-model-levels-with-hybrid-coordinate/1281 "2023-09-13T01:27:40Z")
Dear all, I am downscaling ERA5 reanalysis to higher resolution by using the CCLM regional climate model for the latest month (August. 2023- ). Since only pressure vertical coordinate (37 levels) from ERA5 are availabl… --- ## [How to convert "time" in model HadGEM2-ES in real data from 360 days calendar to Gregorian calendar using serial time (I read and select data by MatLab)](https://forum.ecmwf.int/t/how-to-convert-time-in-model-hadgem2-es-in-real-data-from-360-days-calendar-to-gregorian-calendar-using-serial-time-i-read-and-select-data-by-matlab/1051)
**Author:** [@Tatiana\_Lev](https://forum.ecmwf.int/u/Tatiana_Lev)\ **Replies:** 1\ **Last updated:** [10 August 2023 18:51 UTC](https://forum.ecmwf.int/t/how-to-convert-time-in-model-hadgem2-es-in-real-data-from-360-days-calendar-to-gregorian-calendar-using-serial-time-i-read-and-select-data-by-matlab/1051 "2023-08-10T18:51:32Z")
How to convert “time” in model HadGEM2-ES in real data from 360 days calendar to Gregorian calendar using serial time (I read and select data by MatLab) --- ## [GRIB to NetCDF File | Download as NetCDF File](https://forum.ecmwf.int/t/grib-to-netcdf-file-download-as-netcdf-file/1397)
**Author:** [@Kim\_Cholibois](https://forum.ecmwf.int/u/Kim_Cholibois)\ **Replies:** 7\ **Last updated:** [10 July 2023 06:59 UTC](https://forum.ecmwf.int/t/grib-to-netcdf-file-download-as-netcdf-file/1397 "2023-07-10T06:59:21Z")
Dear all, I have been trying to download Arctic regional reanalysis on single levels from 1991 to present for the following parameters: 10m wind direction, 10m wind speed, 2m temperature, Albedo, Surface net solar radia… --- ## [How to convert CAMS \<2,5 µm (PM2,5) data from kg/m2/s to µg m -3](https://forum.ecmwf.int/t/how-to-convert-cams-2-5-m-pm2-5-data-from-kg-m2-s-to-g-m-3/1054)
**Author:** [@Mariana\_Dias](https://forum.ecmwf.int/u/Mariana_Dias)\ **Replies:** 0\ **Last updated:** [31 March 2023 17:17 UTC](https://forum.ecmwf.int/t/how-to-convert-cams-2-5-m-pm2-5-data-from-kg-m2-s-to-g-m-3/1054 "2023-03-31T17:17:33Z")
Hello, I ask for help to convert pm2.5 emission values which are in kgm-2s-1 to µg m -3. Resolution is 0.1x0.1, daily data. I tried at first to multiply by the number of seconds in a month and the area of a cell of 0.1… --- ## [Pressure data from model levels to heights](https://forum.ecmwf.int/t/pressure-data-from-model-levels-to-heights/1284)
**Author:** [@yasmine\_zakari](https://forum.ecmwf.int/u/yasmine_zakari)\ **Replies:** 18\ **Last updated:** [20 February 2023 08:32 UTC](https://forum.ecmwf.int/t/pressure-data-from-model-levels-to-heights/1284 "2023-02-20T08:32:52Z")
Hey, Has anybody managed to successfully use metview for getting pressure data (era5-complete) from model levels to heights? I used the resources available and keep getting NAN values from metview ml\_to\_hl. Also, the m… --- ## [Thermal Resistivity of Soils](https://forum.ecmwf.int/t/thermal-resistivity-of-soils/1828)
**Author:** [@Sergio\_Montana](https://forum.ecmwf.int/u/Sergio_Montana)\ **Replies:** 0\ **Last updated:** [10 February 2023 10:05 UTC](https://forum.ecmwf.int/t/thermal-resistivity-of-soils/1828 "2023-02-10T10:05:11Z")
Two questions: Exists a matrix conversion between ECMWF type of soil classification and USDA? I'm trying to calculate or find the Thermal resistivity for Extra-Tropical Soil and tropical Soil, anyone have it? --- ## [Conversion from gridtype spectral to gaussian\_reduced](https://forum.ecmwf.int/t/conversion-from-gridtype-spectral-to-gaussian-reduced/1270)
**Author:** [@Mario\_Mech](https://forum.ecmwf.int/u/Mario_Mech)\ **Replies:** 0\ **Last updated:** [21 June 2022 17:48 UTC](https://forum.ecmwf.int/t/conversion-from-gridtype-spectral-to-gaussian-reduced/1270 "2022-06-21T17:48:33Z")
Hej, I'm struggeling a bit with bringing together different parameters from ERA5 available as grib files as surface values or on model levels. For example, I have the specific cloud liquid water content (clwc) or specif… --- ## [How to convert the unit of surface runoff from meter to cubic meter per second?](https://forum.ecmwf.int/t/how-to-convert-the-unit-of-surface-runoff-from-meter-to-cubic-meter-per-second/918)
**Author:** [@Behzad\_Navidi](https://forum.ecmwf.int/u/Behzad_Navidi)\ **Replies:** 0\ **Last updated:** [18 August 2021 19:38 UTC](https://forum.ecmwf.int/t/how-to-convert-the-unit-of-surface-runoff-from-meter-to-cubic-meter-per-second/918 "2021-08-18T19:38:13Z")
Hello all, I downloaded reanalysis-era5-land-monthly-means surface runoff data for my study region from https://cds.climate.copernicus.eu/ with the following details: "product\_type": "monthly\_averaged\_reanalysis", "varia… --- ## [ERA5-Land: Surface solar radiation downwards - daily accumulation to hourly accumulation](https://forum.ecmwf.int/t/era5-land-surface-solar-radiation-downwards-daily-accumulation-to-hourly-accumulation/1584)
**Author:** [@Jeffrey\_Rawlyk](https://forum.ecmwf.int/u/Jeffrey_Rawlyk)\ **Replies:** 0\ **Last updated:** [8 July 2021 16:43 UTC](https://forum.ecmwf.int/t/era5-land-surface-solar-radiation-downwards-daily-accumulation-to-hourly-accumulation/1584 "2021-07-08T16:43:03Z")
Hey folks, Let me provide some context before I really get into the details. I have downloaded the following variables from ERA5-Land in an effort to get some information on weather in an area that we are hoping to cond… --- ## [How to convert ERA5 cloud liquid water content from kg kg^-1 to kg m^3?](https://forum.ecmwf.int/t/how-to-convert-era5-cloud-liquid-water-content-from-kg-kg-1-to-kg-m-3/1215)
**Author:** [@Kevin\_Marsh](https://forum.ecmwf.int/u/Kevin_Marsh)\ **Replies:** 2\ **Last updated:** [20 May 2021 14:44 UTC](https://forum.ecmwf.int/t/how-to-convert-era5-cloud-liquid-water-content-from-kg-kg-1-to-kg-m-3/1215 "2021-05-20T14:44:06Z")
For cloud liquid water in ERA5 there are 2 variables: Specific cloud liquid water content (code 246) on pressure (and model) levels. This parameter has units of kg kg-1, see Table 9 in the ERA5 data documentation. You… --- ## [ERA5- Land hourly data shift time](https://forum.ecmwf.int/t/era5-land-hourly-data-shift-time/1028)
**Author:** [@Puri\_Amrish](https://forum.ecmwf.int/u/Puri_Amrish)\ **Replies:** 1\ **Last updated:** [19 May 2021 03:56 UTC](https://forum.ecmwf.int/t/era5-land-hourly-data-shift-time/1028 "2021-05-19T03:56:08Z")
I downloaded ERA5- Land hrs in 0UTC to 23UTC. I would like to calculate daily data but my region is +9UTC then do I need to shift time? And if yes, how to do that? All the best! --- ## [Converting ERA5-Land surface solar radiation downwards from J/m\*\*2 to W/m\*\*2](https://forum.ecmwf.int/t/converting-era5-land-surface-solar-radiation-downwards-from-j-m-2-to-w-m-2/1318)
**Author:** [@Matt\_Jolly](https://forum.ecmwf.int/u/Matt_Jolly)\ **Replies:** 1\ **Last updated:** [31 March 2021 08:06 UTC](https://forum.ecmwf.int/t/converting-era5-land-surface-solar-radiation-downwards-from-j-m-2-to-w-m-2/1318 "2021-03-31T08:06:35Z")
I have downloaded the surface solar radiation downwards data from the ERA5-Land dataset and I need to convert from J/m\*\*2 to W/m\*\*2. I thought I could just divide the values by 3600 since the data are at hourly timestep… --- ## [Convert NetCDF to CSV](https://forum.ecmwf.int/t/convert-netcdf-to-csv/1242)
**Author:** [@Gizem\_Boztas](https://forum.ecmwf.int/u/Gizem_Boztas)\ **Replies:** 1\ **Last updated:** [11 February 2021 18:07 UTC](https://forum.ecmwf.int/t/convert-netcdf-to-csv/1242 "2021-02-11T18:07:00Z")
Hello, I want to convert my netcdf file to CSV. For this, I reviewed the How to convert NetCDF to CSV page and tried the pyhton codes. But time\_dim, lat\_dim, lon\_dim = tcwv.get\_dims () in this code i get the following … --- ## [Data conversion](https://forum.ecmwf.int/t/data-conversion/861)
**Author:** [@LYDCBruce\_Hyman](https://forum.ecmwf.int/u/LYDCBruce_Hyman)\ **Replies:** 0\ **Last updated:** [13 September 2020 17:58 UTC](https://forum.ecmwf.int/t/data-conversion/861 "2020-09-13T17:58:29Z")
Hello, is there any way to convert reported Carbon Monoxide data (shown in maps as "total column of Carbon Monoxide \[10^18 molecules/cm2\] to ground level ppm, since ground level toxicity is of some health importance? tha… --- ## [Conversion from NetCDF file to a TIFF file](https://forum.ecmwf.int/t/conversion-from-netcdf-file-to-a-tiff-file/1217)
**Author:** [@Michela](https://forum.ecmwf.int/u/Michela)\ **Replies:** 0\ **Last updated:** [31 December 2019 11:56 UTC](https://forum.ecmwf.int/t/conversion-from-netcdf-file-to-a-tiff-file/1217 "2019-12-31T11:56:36Z")
Copernicus program doesn't provide tools that would help users converting the NetCDF file into a TIFF file. However, the following online tool may be useful: https://mygeodata.cloud/converter/netcdf-to-tiff --- ## [Longitude conversion 0~360 to -180~180](https://forum.ecmwf.int/t/longitude-conversion-0-360-to-180-180/1152)
**Author:** [@Xiaobo\_Yang](https://forum.ecmwf.int/u/Xiaobo_Yang)\ **Replies:** 0\ **Last updated:** [27 August 2019 09:18 UTC](https://forum.ecmwf.int/t/longitude-conversion-0-360-to-180-180/1152 "2019-08-27T09:18:19Z")
Longitude can be between 0~360 (long3) and -180~180 (long1). To convert from long3 to long1, use the formula below: long1=mod((long3+180),360)-180 Python: long1 = (long3 + 180) % 360 - 180 Or: if long3 \<= 180: lon…