# Licence of the Dibble climate grid

This file covers `climate-grid-v2.dbcg`, the global grid of typical monthly weather that Dibble 2.0 uses to work out frost
dates and planting windows for a place. It does not cover the Dibble app, its code, or its other content.

## The licence

The grid is a derived database. It is built from the Climatic Research Unit's CRU TS data, whose publisher offers it under the
Open Database License, and that licence asks anyone who adapts the database to offer the result under the same terms. So Handler
Labs LLC offers `climate-grid-v2.dbcg` to everyone under the **Open Database License (ODbL) 1.0**:

* Licence text: https://opendatacommons.org/licenses/odbl/1.0/
* Plain summary: https://opendatacommons.org/licenses/odbl/summary/

The individual values in the grid (a temperature or a rainfall figure for one cell and month) are offered under the Database
Contents License 1.0, https://opendatacommons.org/licenses/dbcl/1.0/, as CRU states for its own data.

In short, you may copy, share, use, and adapt the grid, for any purpose including commercial use, as long as you:

1. **Attribute it.** Credit the sources below and say that the grid comes from Dibble (Handler Labs LLC).
2. **Share alike.** If you publish an adapted version of the grid, offer your version under the ODbL too, and keep this notice.
3. **Keep it open.** If you redistribute the grid in a form that uses technical measures to restrict others, also offer a version
   without them.

The plantings, dates and calendars an app shows from the grid are works produced from it. They need the attribution, not the
share-alike.

## Where the grid is published

Alongside the website, so that the licence terms are met by anyone who has the app:

* https://dibblegarden.com/data/climate/climate-grid-v2.dbcg
* https://dibblegarden.com/data/climate/LICENSE-climate-grid.md

The file format is described in `content/climate/README.md`, and the scripts that build the grid from the sources below are in
`scripts/climate/`. The file in the app is byte for byte the file published on the website.

* File: `climate-grid-v2.dbcg`, 2,857,054 bytes
* SHA-256: `db455ef5026d99cf8fc8c1feef9a0e1bc73d9b10e23997085632276af692fd0e`

## What it is made from, and the credits

**CRU TS v4.10 (monthly temperature and rainfall)**
Climatic Research Unit, University of East Anglia. The variables tmx (mean daily maximum temperature), tmn (mean daily minimum
temperature) and pre (rainfall), 1991 to 2020 monthly normals, 0.5 degree cells over land. Harris, I., Osborn, T.J., Jones, P. and
Lister, D., 2020, "Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset", Scientific Data 7, 109,
https://doi.org/10.1038/s41597-020-0453-3. Published at https://crudata.uea.ac.uk/cru/data/hrg/ under the Open Database License.
Attribution requested by the publisher: "Climatic Research Unit, University of East Anglia".

**GHCN-Daily (station correction)**
NOAA National Centers for Environmental Information. Monthly means from weather stations, 1991 to 2020, used to correct the CRU
values toward what stations record (629 stations, each cell moved by a smoothed field of station minus grid differences). Menne,
M.J. et al., 2012, "Global Historical Climatology Network Daily (GHCN-Daily), Version 3", NOAA NCEI,
https://doi.org/10.7289/V5D21VHZ. A United States government work, in the public domain.

**GMTED2010 (elevation)**
US Geological Survey. Mean elevation of the land in each cell, so that Dibble can adjust the grid for the height of a garden.
Danielson, J.J. and Gesch, D.B., 2011, "Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010)", US Geological Survey
Open-File Report 2011-1073. A United States government work, in the public domain.

**NASA POWER (fallback for open water and small islands)**
The file also carries a coarser grid, used only for places with no land cell within 30 km. The data was obtained from National
Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project
funded through the NASA Earth Science Division, https://power.larc.nasa.gov/docs/referencing/.

## What was changed

The CRU values were averaged to monthly normals, paired with the GMTED2010 elevation of each cell's land, moved by the GHCN-Daily
station correction, and packed into the compact binary format `climate-grid-v2.dbcg` (temperatures in steps of 0.3 C and rainfall
within 2 percent of the source). The NASA POWER grid is embedded unchanged as the fallback. The values are typical weather for
a 0.5 degree cell, not a measurement at a point: mountains, coasts and cities can differ by several degrees.

## No warranty

The grid is provided as is, without warranty of any kind, under the terms of the ODbL. Questions about the grid or this licence:
support@handlerlabs.app.