Hi @ymcmrs,
The correction from ICAMS assumes altitude levels starting from -200 m, and going upward to 40 km.
In addition, whenever the altitude is below -200 m, it is set to -100 m. Why do we need this checking and why not set it to just -200 m?
The minimum elevation, for most regions, I guess is alright. But I work on the Dead Sea Valley, where the basin's elevation is around -400 m. This results in NaN values for the ICAMS time series at the pixels below -200 m, as the image shows within the valley between latitude 31 deg and 32 deg. (This image is the apparent velocity field of an ICAMS-generated time-series file, representing the trend of the ERA5 model).
a zoom in at the valley where weird values occur. The water body here is masked out.
Can I simply modify the code and let the altitude grids start from -400 m? Is there anything related that I should be aware of?
Side question, I also saw PyAPS having the same min altitude of -200 m. Is -200 m the lower bound of the ERA5 weather models? Or it is a somehow safe way to set for interpolation? From the ECMWF website it seems like the model are down to the Earth's surface.
Thanks for your help!
Hi @ymcmrs,
The correction from ICAMS assumes altitude levels starting from -200 m, and going upward to 40 km.
In addition, whenever the altitude is below -200 m, it is set to -100 m. Why do we need this checking and why not set it to just -200 m?
The minimum elevation, for most regions, I guess is alright. But I work on the Dead Sea Valley, where the basin's elevation is around -400 m. This results in NaN values for the ICAMS time series at the pixels below -200 m, as the image shows within the valley between latitude 31 deg and 32 deg. (This image is the apparent velocity field of an ICAMS-generated time-series file, representing the trend of the ERA5 model).
a zoom in at the valley where weird values occur. The water body here is masked out.
Can I simply modify the code and let the altitude grids start from -400 m? Is there anything related that I should be aware of?
Side question, I also saw PyAPS having the same min altitude of -200 m. Is -200 m the lower bound of the ERA5 weather models? Or it is a somehow safe way to set for interpolation? From the ECMWF website it seems like the model are down to the Earth's surface.
Thanks for your help!