I downloaded data from the CAMS Global near-real-time archive or other CAMS Global products, and for aerosol optical depth (AOD) and particulate matter (PM10, PM2.5) the values are all zero.
This is a known issue. It is due to a bug that caused AOD and PM to not be computed for Step 0 (analysis time), and zeros were stored instead.
Affected Species are AOD and PM, and only at forecast step 0. Subsequent steps are computed as designed.
Affected datasets are the CAMS Global Near-Real-Time forecasts, the CAMS interim Reanalysis (CAMSiRA), and potentially other CAMS global datasets.
For AOD a fix was implemented, and since 24 January 2017 AOD at forecast step 0 is available.
For PM a fix will be implemented in 2017.
Workaround: Download data with forecast steps other than 0. For example, you need data for validity time 2015-01-01, 00:00. In this case do not download data for 2015-01-01, 00:00, step 0 (base time + 0 hours forecast). Instead, download for example data for 2014-12-13, 12:00, step 12 (base time + 12 hours forecast), which also results in a validity time 2015-01-01, 00:00.
For more information on system changes please see https://atmosphere.copernicus.eu/changes-cams-global-production-system