Metadata for this dataset is available on the CMAS Dataverse Entry for AMET
The link for the AWS Open Dataset that this readme describes is AMET Dataset on AWS S3 Bucket>

Downloading data from S3 Bucket

This dataset is available as part of the AWS Open Data Program, therefore egress fees are not charged to either the host or the person downloading the data.
The data directories are structured as follows:

AMET
	2000_2023_NAmerican_AQ_Obs_Data
	AMET_Release_Observation_Files_Readme_3_26_2024.txt
	obs_overlay
	v1.5_example
		MET
			metExample_mcip
			metExample_mpas
			metExample_wrf
		AQ
			aqExample
				COMBINE_ACONC_aqExample_201607.nc
				COMBINE_DEP_aqExample_201607.nc
	v1.6_example
		note - the MET has not changed for the AMETv1.6 release, please use the MET files available in v1.5_example above
		AQ
			aqExample
				COMBINE_ACONC_aqExample_201807.nc
				COMBINE_DEP_aqExample_201807.nc
				output

Instructions for downloading the aws command line.

Instructions to Download AWS Command Line
Once you have it installed, you can use it without credentials.
Example commands:
To query how much data is in a bucket:

aws s3 ls --summarize --region=us-east-1 --human-readable --recursive s3://cmas-amet

Tail of Output:

2025-04-28 16:25:29  134.8 KiB AMET/v1.6_example/AQ/output/timeseries_plotly/aqExample_O3_8hrmax_1_timeseries_files/jquery-3.5.1/jquery.min.map
2025-04-28 16:25:30   33.0 KiB AMET/v1.6_example/AQ/output/timeseries_plotly/aqExample_O3_8hrmax_1_timeseries_files/plotly-binding-4.10.4/plotly.js
2025-04-28 16:25:30  173 Bytes AMET/v1.6_example/AQ/output/timeseries_plotly/aqExample_O3_8hrmax_1_timeseries_files/plotly-htmlwidgets-css-2.11.1/plotly-htmlwidgets.css
2025-04-28 16:25:31    3.5 MiB AMET/v1.6_example/AQ/output/timeseries_plotly/aqExample_O3_8hrmax_1_timeseries_files/plotly-main-2.11.1/plotly-latest.min.js
2025-04-28 16:25:31   21.9 KiB AMET/v1.6_example/AQ/output/timeseries_plotly/aqExample_O3_8hrmax_1_timeseries_files/typedarray-0.1/typedarray.min.js
2022-05-12 10:53:20   30.9 KiB index.html
2025-08-25 13:27:24    2.0 KiB readme.html

Total Objects: 16502
   Total Size: 972.1 GiB

Command to copy files from the bucket to your local filesystem (the system where you are running the aws cli) and place it under the path that you specify for /your_local_path.

aws s3 --no-sign-request --region=us-east-1 cp --recursive s3://cmas-amet/AMET/v1.6_example/ /your_local_path/AMET/v1.6_example/

Please submit any questions or difficulties as a new issue on the CMAS User Forum.
CMAS User Forum