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Questions tagged [era5]

ERA5 is a new state-of-the-art gridded reanalysis product covering the period 1979 to the present and available through the Copernicus climate data store through a web interface or a python api. The dataset includes a wide range of climate variables, the most popular including hourly rainfall, 2 meter temperatures and sea surface temperature

ERA5 is a new state-of-the-art gridded reanalysis product covering the period 1979 to the present and available through the Copernicus climate data store through a web interface or a python api. The dataset includes a wide range of climate variables, the most popular including hourly rainfall, 2 meter temperatures and sea surface temperature

58 questions
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Errors when using metpy to calculate specific humidity

I would like to use metpy to calculate the near-surface (i.e. 2m) specific humidity using ERA5 hourly reanalysis data. I just installed metpy locally yesterday via pip, so I'm assuming that my code is up-to-date. My problem is that I keep running…
DanJonesOcean
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How to calculate total precipitation per day using hourly data for whole year?

I have hourly data from ERA5 for each day in a specific year. I want to convert that data from hourly to daily. I know the long and hard way to do it, but I need something which does that easily. Copernicus has a code for this here…
Ep1c1aN
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Extract a time and space variable from a moving ship from the ERA5 reanalysis

I want to extract the measured wind from a station inside a moving ship, which I have the latitude, longitude and time values and the wind value for each time step in space. I can extract a fixed point in space for all time steps but I would like to…
William Jacondino
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Calculating ERA5 Daily Total Precipitation using CDO

Essentially, this is a repost of this question: https://confluence.ecmwf.int/pages/viewpage.action?pageId=149341027 I have downloaded ERA5 from the CDS. The input file has 24 hourly steps (0, 1, 2, 3, 4,..,23) for each calendar day starting from Jan…
Moritz Schwarz
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How manipulate ERA5 land hourly data with Python?

I recently started to use ERA5 land-hourly data and python code. I will use data of 2 variables (total precipitation and 2 metre temperature) from an entire year (2017). Data downloaded are in GRIB or netCDF format. The things I want to do are: 1)…
Brian
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Xarray / Dask - Compute the highest temperature for every coordinate

I have a 17GB GRIB file containing temperature (t2m) data for every hour of year 2020. The dimensions of Dataset are longitude, latitude, and time. My goal is to compute the highest temperature for every coordinate (lon,lat) in data for the whole…
eMad
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Moisture flux divergence using numpy and metpy differ

As described in this question I want to calculate moisture flux divergence at 850 hPa. For this, I have used the code described here, which makes use of the np.gradient function from the numpy package. The code I am using is this: from matplotlib…
Maria Chara Karypidou
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Minor differences in values dependent on queried area size

I noticed that depending on the size of the queried area using CDS API (more specifically the cdsapi Python library), I receive slightly different values of precipitations for the same coordinates. Let's take an example: I want to get daily…
KJarocki
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Is there a way to delete time values in an xarray dataset that does not meet a certain time value?

This ERA5 dataset, made up of netCDF files, comes in time values of %Y-%m-%dT%h:%M%s %p and they are given hourly. So, for 31 days, there are 744-time values. I only want to take the 12:00:00 value for each day so that I have 31 data points.…
Matthew Graber
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Adding unique ID number to heatwave events (tagging consecutive days) in xarray dataset and add as a variable to the dataset

I am working with ERA5 data (daily temperature of 30 years) to identify heatwaves (HW). A HW event is defined as at least 3 consecutive days exceeding the threshold. I have calculated EHF, i.e. Excess Heat Factor and the threshold for HW is set to…
Salit
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cdsapi error while trying to download era5 data using python script

I'm trying to download ERA5 best-track data (hourly, single level) with CDS API. I'm totally new to get this kind of dataset, so I've running into bunch of errors like this. This is the script: import cdsapi import numpy import…
shibashiba
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Discrepancy in data on total precipitation from ERA5 monthly vs daily data

I am using data on total precipitation in January 2015 for an area in Nigeria from the ERA5, but I am getting very different values using each of the following two methods below. What am I doing wrong? Daily mean statistic of ERA hourly data on…
Giorgio Maarrawi
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How to count number of events of length 5<=N<10 days meeting a set condition using CDO?

I need a help regarding CDO operation on a netcdf file. I downloaded dataset for 40 years from ERA5 over a grid region and I masked variable values for a range (30-50) to 1 and other values to 0 using cdo. cdo -expr,'var2=var*(var>=30 && var<50)'…
Nithin Krishna
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Significant increase in file size (x10) after applying function on NetCDF data using xarray

I am working on ERA5 reanalysis data in NetCDF format, and I need to compute wind direction based on U and V components. I already have a working piece of Python code to do so using xarray and pandas, and saving output as NetCDF. While I do not add…
Beinje
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Thoughts on how to speed up replacing a column value when conditions between two objects (dataframe or datatable) are met in a loop?

I'm trying to get some input on how I might speed up a for loop that I've written. Essentially, I have a dataframe (DF1) where each row provides the latitude and longitude/point at a given time. The variables therefore are the lat and long for the…
Tham v
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