> For the complete documentation index, see [llms.txt](https://brightwind.gitbook.io/brighthub-user-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://brightwind.gitbook.io/brighthub-user-docs/quick-start-guide/download-reanalysis-data.md).

# Download Reanalysis Data

MERRA-2 and ERA-5 global reanalysis datasets are important long term reference datasets for wind resource analysis. 

Although openly available from NASA and ECMWF respectively, the raw source files are typically complicated to download and interrogate for use in a long term analysis. 

BrightHub streamlines this process so you can download reanalysis data in a format tailored for wind resource analysis.

### Download Reanalysis from User Interface

Watch the video below for a demonstration of how to download reanalysis data from the [map page](/brighthub-user-docs/quick-start-guide/navigate-map-page.md) on BrightHub:

{% embed url="<https://www.youtube.com/watch?v=q8-0E4f_BHw>" %}
Download Reanalysis Data via BrightHub UI
{% endembed %}

To download ERA5 or MERRA-2 from BrightHub via the user interface:

{% stepper %}
{% step %}

### Go to the BrightHub [map page](/brighthub-user-docs/quick-start-guide/navigate-map-page.md).

{% endstep %}

{% step %}

### Select a reanalysis node.

Click on your choice of MERRA-2 or ERA5 in the side bar so you can view reanalysis node locations.&#x20;

Zoom into the region for the reanalysis node icons to appear.

Click on the icon of your chosen reanalysis node.
{% endstep %}

{% step %}

### Select variables

Choose the variables you would like to download from wind speed, wind direction, temperature or pressure.
{% endstep %}

{% step %}

### Select date range

Use the slider to select the date range of interest.
{% endstep %}

{% step %}

### Download

Click 'Download' to download a csv with hourly reanalysis data for the node, time period and variables specified.
{% endstep %}
{% endstepper %}

***

### Download Reanalysis using Python

Alternatively, you can download reanalysis data from BrightHub using the open source [brightwind Python library](https://github.com/brightwind-dev/brightwind) as demonstrated in the video below:

{% embed url="<https://www.youtube.com/watch?v=l8zePS8fA0A>" %}
Download Reananalysis Data via brightwind Python library
{% endembed %}

To find out more about using BrightHub in conjunction with the open source brightwind library in Python, see our [BrightHub Python User Guide](/brighthub-user-docs/brighthub-python-user-guide.md).


---

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