# Converting ERA5-Land surface solar radiation downwards from J/m\*\*2 to W/m\*\*2

**URL:** <https://forum.ecmwf.int/t/converting-era5-land-surface-solar-radiation-downwards-from-j-m-2-to-w-m-2/1318>\
**Category:** C3S - Datasets and Usage\
**Tags:** c3s, conversion, era5-land\
**Created:** [30 March 2021 20:34 UTC](https://forum.ecmwf.int/t/converting-era5-land-surface-solar-radiation-downwards-from-j-m-2-to-w-m-2/1318 "2021-03-30T20:34:24Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Matt\_Jolly](https://forum.ecmwf.int/letter_avatar_proxy/v4/letter/m/dec6dc/32.png) [@Matt\_Jolly](https://forum.ecmwf.int/u/Matt_Jolly)\
**Post date:** [30 March 2021 20:34 UTC](https://forum.ecmwf.int/t/converting-era5-land-surface-solar-radiation-downwards-from-j-m-2-to-w-m-2/1318/1 "2021-03-30T20:34:24Z")

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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.&nbsp; I thought I could just divide the values by 3600 since the data are at hourly timesteps but the results are much too high (about 6 times top of atmosphere radiation). Can someone please share the appropriate accumulation period for these solar radiation data?

Thanks!

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**Author:** ![Anabelle](https://forum.ecmwf.int/user_avatar/forum.ecmwf.int/anabelle/32/360_2.png) [@Anabelle](https://forum.ecmwf.int/u/Anabelle)\
**Post date:** [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-2/1318/2 "2021-03-31T08:06:35Z")

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How about you check this [Conversion table for accumulated variables (total precipitation/fluxes)](https://confluence.ecmwf.int/pages/viewpage.action?pageId=197702790)

Hope this helps!