Total number of measurements of the LIMNADES database. (A) Fully open licence, (b) Fully open-non-commercial licence, (c) Open, attribution licence, (D) Open, attribution licence non-commercial, (E) Open, attribution with co- authorship, (F) Temporary storage and use in internal projects Figure 3. Global distribution of LIMNADES data collection Gaps in data The current version of LIMNADES database stopped collating data in 2019, but will contain additional data sets after the release of a new version in autumn 2021. Types of data use licences are varied, but in many cases, data can only be distributed and used with some limitations (D and E) that required direct permission from data owners, co-authoring if documents or papers are written, and have a strong requirement on non-commercial use. For future datasets, a more open data policy is envisaged. Chapter 5 provides a more detailed overview of the water quality data in LIMNADES. Only chlorophyll-a and TSM have a reasonably good representation in LIMNADES; there is a lot less data available on absorption of CDOM and phycocyanin. Remote sensing reflectance (Rrs) is only available from 2000 to 2015 and most of it has licence E. The release of the new version would need a new assessment of the available data sets. Restrictions in data There are several types of data licences (see Figure 1 and Table 1). Many of the licences held within the LIMNADES database are request only data licences (C-E), meaning that if you are interested in that data you will have to make a request to that particular data owner. A smaller percentage is open access and free to download (A-B). The data base is currently only accessible to users who also provide data to the database. This currently poses a major limitation on access to the data for researchers that cannot contribute to measurements. This is planned to change in the future, when an embargo time (approximately two years) is put in place for new project data contributed, before these data go public.
