Merge pull request #384 from GeoscienceAustralia/alert/s2c-21jan2025

Tech alert: Sentinel-2A data switching over to Sentinel-2C

docs/tech-alerts/_content.md

@@ -8,6 +8,12 @@
 Learn more about the [DEA Summary Product Grid](/guides/reference/collection_3_summary_grid/).
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+## 21 Jan 2025: Sentinel-2A data switching over to Sentinel-2C
+
+Digital Earth Australia’s Sentinel-2A data products will stop publishing data updates on 21 January 2025. They will be replaced with equivalent Sentinel-2C data products, which will begin publishing data shortly after. For further information on the precise timing of the transfer, please see [Sentinel Online](https://sentinel.esa.int/web/sentinel/-/precise-timing-of-transfer-of-duty-from-sentinel-2a-to-sentinel-2c-on-21-january). The historical Sentinel-2A data will still be provided as public data. A new ga_s2cm_ard_3 product will begin receiving data for both our NRT and definitive offerings within the coming weeks. 
+
+[View the Tech Alert](https://communication.ga.gov.au/link/id/zzzz678f06dcdfdd9113Pzzzz6567c8b713b5b826/page.html)
+
 ## 08 Jan 2025: DEA Maps data not up-to-date
 
 [DEA Maps](/guides/setup/dea_maps/) and [OWS layers](/guides/setup/gis/README/) are not currently up-to-date with the data available on [DEA AWS](/guides/setup/AWS/data_and_metadata/). We are investigating the cause of this issue.