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Add CMIP6 files #323

Merged
merged 11 commits into from
Oct 6, 2023
1 change: 1 addition & 0 deletions .env
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Expand Up @@ -12,6 +12,7 @@ API_RASTER_ENDPOINT='https://staging-raster.delta-backend.com'

# Endpoint for the STAC server. No trailing slash.
API_STAC_ENDPOINT='https://staging-stac.delta-backend.com'
API_XARRAY_ENDPOINT='https://dev-titiler-xarray.delta-backend.com/tilejson.json'

MAPBOX_STYLE_URL='mapbox://styles/covid-nasa/ckb01h6f10bn81iqg98ne0i2y'

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81 changes: 81 additions & 0 deletions datasets/cmip6-tas.data.mdx
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---
id: combined_CMIP6_daily_GISS-E2-1-G_tas_kerchunk_DEMO
name: 'CMIP6 Daily GISS-E2-1-G Near-Surface Air Temperature (demo subset)'
featured: false
description: "Daily near-surface air temperature from the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6) Project."
media:
src: ::file ./cmip6-tas.png
alt: CMIP6 Near-Surface Air Temperature Screenshot
author:
name: NASA
url:
taxonomy:
- name: Topics
values:
- Climate
layers:
- id: combined_CMIP6_daily_GISS-E2-1-G_tas_kerchunk_DEMO
stacCol: combined_CMIP6_daily_GISS-E2-1-G_tas_kerchunk_DEMO
name: CMIP6 Daily GISS-E2-1-G Near-Surface Air Temperature (demo subset)
type: zarr
description: "Historical (1950-2014) daily-mean near-surface (usually, 2 meter) air temperature in Kelvin."
zoomExtent:
- 0
- 20
sourceParams:
reference: "true"
resampling_method: bilinear
variable: tas
colormap_name: coolwarm
rescale: 232,312
maxzoom: 12
legend:
unit:
label: K
type: gradient
min: 232
max: 312
stops:
- '#3b4cc0'
- '#7b9ff9'
- '#c0d4f5'
- '#f2cbb7'
- '#ee8468'
- '#b40426'
---

<Block>
<Prose>
# NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6)

The NEX-GDDP-CMIP6 dataset provide a set of global, high resolution, bias-corrected climate change projections that can be used to evaluate climate change impacts on processes that are sensitive to finer-scale climate gradients and the effects of local topography on climate conditions.

NEX-GDDP-CMIP6 is comprised of global downscaled climate scenarios derived from the General Circulation Model (GCM) runs conducted under the Coupled Model Intercomparison Project Phase 6 (CMIP6) and across all four “Tier 1” greenhouse gas emissions scenarios known as Shared Socioeconomic Pathways (SSPs). The CMIP6 GCM runs were developed in support of the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR6). This dataset includes downscaled projections from ScenarioMIP model runs for which daily scenarios were produced and distributed through the Earth System Grid Federation.

### Summary

* Format: [kerchunk (metadata)](https://fsspec.github.io/kerchunk/) for netCDF4
* Spatial Coverage: 180° W to 180° E, 60° S to 90° N
* Temporal: 1950-01-01 to 1951-12-31
* _As noted below, this dataset is a subset all available data. The full dataset includes data from 1950 to 2100._
* Data Resolution:
* Latitude Resolution: 0.25 degrees (25 km)
* Longitude Resolution: 0.25 degrees (25 km)
* Temporal Resolution: daily

Source: [https://www.nccs.nasa.gov/services/data-collections/land-based-products/nex-gddp-cmip6](https://www.nccs.nasa.gov/services/data-collections/land-based-products/nex-gddp-cmip6)

## AWS Public Dataset

There are 2 datasets listed on the AWS Registry of Open Data for [NEX-GDDP-CMIP6](https://registry.opendata.aws/nex-gddp-cmip6/). First, there is an archive of NetCDF files from about 35 different climate models, each supplying historical and predicted values for up to 9 environment variables, daily, from 1950 to 2100. Second, there is an archive of COGs generated from the corresponding NetCDFs to support visualization via dynamic tiling using COGs. COGs are only available for 2 models. The COG archive also includes monthly aggregatations across those models.

## Dataset Preparation

### This dataset represents a subset of NEX-GDDP-CMIP6

VEDA is hosting a single JSON file which references a subset of the NEX-GDDP-CMIP6 data in NetCDF. We used the [kerchunk](https://fsspec.github.io/kerchunk/) python library to create a JSON file - often called a reference file - which is an index of the chunks of the data stored in the original [NetCDF](https://www.unidata.ucar.edu/software/netcdf/) files. This can be considered a "virtual" Zarr dataset. The virtual Zarr dataset (aka the kerchunk reference file) is used by a dynamic tiling library ([titiler-xarray](https://github.com/developmentseed/titiler-xarray)) to create image tiles from the underlying data. The indexes were generated for the near-surface air temperature variable (TAS) for years 1950-2014, the historical extent of the NEX-GDDP-CMIP6 project.

We are using these methods to demonstrate a method for visualizing a "virtual" Zarr dataset which allows for dynamic visualization without having to create and maintain any additional copies of data.

</Prose>
</Block>
Binary file added datasets/cmip6-tas.png
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