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Plotting ERA5 U/V Wind Data Using Python

First off very few people are using Basemap from Matplotlib these days. From this link matplot basemap Basemap is deprecated in favor of the Cartopy project. See notes in Cartopy, New Management, ...
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8 votes
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difference between different meteorological models

In general, the relation between the three datasets is as follows: The simulation model is initiated with a set of boundary and initial conditions, and will on the long-term provide good mean ...
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  • 98
6 votes
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ERA Interim, how to handle total precipitation

First of all, these netCDF files follow the CF Metadata Conventions, which describe the use of scale_factor and add_offset in ...
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6 votes
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What is the meaning of step in ERA reanalysis data?

The "step" is the number of hours the ERA re-forecast has been run into the future from the "time" of the re-analysis. For example, asking for ERA data with time = 12:00 and step = 0 means asking for ...
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  • 1,662
6 votes
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ERA5 mean evaporation rates data - Why is that negative?

Just leaving this for future readers. I finally found in some ECMWF documentation (referring to a different variable) that: "The ECMWF Integrated Forecasting System convention is that downward fluxes ...
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5 votes
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Extracting Regional Data from ERA5

To me I am not sure why the subset option should not work with a python script. According to me it does work. Here is a sample script. ...
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  • 6,257
5 votes
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How to calculate 3-hour flux values in ERA-Interim?

After my original answer, and some back and forth in the comments, turns out I got the answer right by a bit of fools luck, and we sorted it out... The thing is, despite flux being commonly thought ...
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5 votes

Why is radiation and total precipitation not available in ERA Interim Reanalysis at step 0?

The ERA archive description document, Berrisford et al (2011) "The ERA-Interim archive Version 2.0", provides additional information about what is available. It's less explicit on the why, but we can ...
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  • 3,133
5 votes

Uncertainty In ERA-Interim data

There is no traceable uncertainty associated with each datum in the ERA-Interim reanalysis. However, in ERA-5 there is an ensemble. This multiplies the data volume, but it means you can use the ...
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4 votes
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Why is ferret giving me error that the region is not 2D while plotting

You need to use the following syntax yes? fill 't'[k=1,l=1] This is because ferret treats t variable name as time and to distinguish your variable name (if it is ...
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4 votes
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ERA Interim problem with Waves

I haven't looked into ERA-Interim wave data a huge amount but I know around 1991 it started to assimilate ocean wave data from satellite altimeters (ERS-1). See the first figure here https://...
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3 votes
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Can we call the Precambrian eons (i.e. Archaic and Proterozoic) eras?

It is and is not an an error depending on how it is used. They are Eons but in older literature they were also, sort of, eras as the Eons were not subdivided as they are now. Especially in literature ...
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3 votes
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Error trying to download ERA5 data: Exception: Missing/incomplete configuration file: C:\Users\username/.cdsapirc

I had the same problem but have just found the solution after an hour or so of trawling through forums! The problem was that the code 'api.py' could not find the '.cdsapirc' file. The file type has to ...
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2 votes

ERA-Interim how to select only grid-points over land area?

The simplest way is to download another variable in which data is only available over the ocean, such as Sea Surface Temperature (SST). You should be able to download it in the very same way you do ...
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  • 587
2 votes

How to calculate Lifted Index from ERA5 pressure level data?

Metpy 1.0 has a lifted_index function, which requires a profile temperature parameter, which in turn can be calculated using the parcel_profile function. That requires having the dew point temperature,...
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2 votes

downloading ERA5 netCDF daily data for a decade, how to restrict location to reduce data size?

There are two ways to get this done: 1- you can select the specific domain of interest when downloading the files. This is highly preferred when you have to download a large number of variables and ...
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  • 1,248
2 votes
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How accurate is ERA5 weather data?

The paper that describes ERA-5 (Hersbach et al., 2020) includes an entire section (Section 7) on the accuracy of the model after data assimilation. As the model assimilates a considerable amount of ...
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1 vote
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What is the correct way to report historical daily Max / Min / Avg Temperature by City?

I don't know if ERA5 data has some weird format, as I'm really not familiar with working with such data directly. But it's vital to realize that the greatest hourly temp is rarely the daily max, and ...
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1 vote

What is the correct way to report historical daily Max / Min / Avg Temperature by City?

Yes, daily minima, maxima and precipitation totals are calculated simply as you suggested in your question. Take care that there aren't missing values,, but that's more of an issue calculating means. ...
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  • 1,206
1 vote

Direct and Diffused component of shortwave radiation in ERA5 data

This paper By Fiddes & Gruber (TopoSCALE: downscaling gridded climate data in complex terrain) provides a method to partition direct and diffuse from ERA-Interim. The results could easily be ...
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1 vote

How to calculate 'real-world' geometric height from ERA reanalysis data

I have two solutions. Use MetPy to calculate the height from the geopotential height. Use the hypsometric equation, averaging the temperature below the level.
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1 vote

How to calculate 'real-world' geometric height from ERA reanalysis data

If I understood the question right: CDO can interpolate from model level to height level with the operator ml2hl infile.nc outfile.nc additionally, for the lower atmospheric levels, you can add an ...
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1 vote

How reliable is sea-ice concentration (fraction) data in ERA-Interim?

I would recommend changing from ERA-Interim to ERA-5, since ERA-Interim will be outdated soon. This is the information currently given by the data provider: ERA Interim is being phased out. Users ...
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  • 387
1 vote

ERA-Interim how to select only grid-points over land area?

The land-sea mask for ERA Interim is available here.
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  • 387
1 vote

Extracting Regional Data from ERA5

Any Python/R packages that can extract and plot these data in an efficient way? I can highly recommend using the Python package xarray or iris for data analysis and Cartopy for plotting.
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  • 387
1 vote

run the WRF model using ERA5

Did you use the right Vtable? That error message is saying that the soil temperature variable is missing/couldn't be read.
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1 vote

ERA Interim problem with Waves

This doesn't answer your question but I can't comment; It is worth noting that there are several changes in SST packages which drive the models. The most significant is the difference from before ...
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1 vote

What is the meaning of step in ERA reanalysis data?

Some confusion comes from the mixture of analysis data (such as 2m-air temperature) and reanalysis products (such as downward radiation) in the final reanalysis product. The following text directly ...
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