{ "cells": [ { "cell_type": "markdown", "id": "md0", "metadata": {}, "source": [ "# AtmosPair \u2014 paired ERA5 / WRF downscaling walkthrough\n", "\n", "A hands-on guide for loading the **AtmosPair** dataset: paired ERA5 (input) and WRF (target) atmospheric fields over the U.S. Mid-Atlantic for **2007\u20132015**, designed for supervised downscaling.\n", "\n", "| | |\n", "| --- | --- |\n", "| **Dataset** | [`era5wrf/atmospair`](https://huggingface.co/datasets/era5wrf/atmospair) on Hugging Face |\n", "| **License** | CC-BY-4.0 |\n", "| **Format** | Zarr (consolidated) |\n", "| **Shape** | 26,296 timesteps \u00b7 68 ERA5 + 49 WRF channels \u00b7 112 \u00d7 112 grid |\n", "\n", "---\n", "\n", "**What this notebook covers**\n", "\n", "1. Open the Zarr store with xarray and inspect its layout\n", "2. Read the ERA5 / WRF **variable manifests** (channel index, variable name, pressure level, center, scale)\n", "3. Build **train** and **validation** `Dataset` / `DataLoader` objects for supervised downscaling\n", "4. Verify the **normalization round-trip** (`normalize_*` \u2194 `denormalize_*`)\n", "5. Visualise a **paired sample** interactively with channel dropdowns and a timestep slider" ] }, { "cell_type": "markdown", "id": "md1", "metadata": {}, "source": [ "## Where to get the data\n\nThree ways to point the notebook at a data source. Pick one and assign to `DATA` further down.\n\n| Option | Size | How to get it |\n| --- | --- | --- |\n| **Stream the sample from HF** (no download) | ~1 GB | `DATA = \"hf://datasets/era5wrf/atmospair/atmospair_sample.zarr\"` |\n| **Download the sample** (July 2015) | ~1 GB | `huggingface-cli download era5wrf/atmospair atmospair_sample.zarr --repo-type dataset --local-dir ./atmospair_data` |\n| **Download the full corpus** (tar archive) | ~95 GB | `huggingface-cli download era5wrf/atmospair atmospair.zarr.tar --repo-type dataset --local-dir ./atmospair_data` |\n\nAfter downloading the full corpus, untar it once locally:\n\n```bash\ntar -xf ./atmospair_data/atmospair.zarr.tar -C ./atmospair_data\n```\n\nThen point `DATA` at the extracted folder:\n\n```python\nDATA = Path(\"./atmospair_data/atmospair.zarr\")\n```\n\nThe reference `Dataset` class lives in the same HF repo as `example_dataset.py`. To grab it programmatically:\n\n```python\nfrom huggingface_hub import hf_hub_download\nhf_hub_download(\"era5wrf/atmospair\", \"example_dataset.py\", repo_type=\"dataset\")\n```\n\n> **Tip.** Start with the sample subset to verify the pipeline end-to-end, then download and untar the full corpus for training." ] }, { "cell_type": "markdown", "id": "md_intro_deps", "metadata": {}, "source": [ "## Dependencies\n", "\n", "`xarray` \u00b7 `zarr<3` \u00b7 `numpy` \u00b7 `pandas` \u00b7 `matplotlib` \u00b7 `torch` \u00b7 `ipywidgets` \u00b7 `huggingface_hub`\n", "\n", "Uncomment the install line below if running in a fresh environment." ] }, { "cell_type": "code", "execution_count": 1, "id": "cd2", "metadata": { "execution": { "iopub.execute_input": "2026-05-04T22:45:16.680076Z", "iopub.status.busy": "2026-05-04T22:45:16.679837Z", "iopub.status.idle": "2026-05-04T22:45:16.684217Z", "shell.execute_reply": "2026-05-04T22:45:16.683432Z" } }, "outputs": [], "source": [ "# !pip install --quiet xarray 'zarr<3' numpy pandas matplotlib torch ipywidgets huggingface_hub" ] }, { "cell_type": "code", "execution_count": 2, "id": "cd3", "metadata": { "execution": { "iopub.execute_input": "2026-05-04T22:45:16.686034Z", "iopub.status.busy": "2026-05-04T22:45:16.685887Z", "iopub.status.idle": "2026-05-04T22:45:18.238726Z", "shell.execute_reply": "2026-05-04T22:45:18.238374Z" } }, "outputs": [], "source": [ "from pathlib import Path\n", "\n", "import numpy as np\n", "import pandas as pd\n", "import xarray as xr\n", "import matplotlib.pyplot as plt\n", "import torch\n", "from torch.utils.data import DataLoader\n", "from ipywidgets import interact, Dropdown, IntSlider" ] }, { "cell_type": "markdown", "id": "md4", "metadata": {}, "source": [ "## Locate the dataset\n", "\n", "Three options. Pick one and assign to `DATA`." ] }, { "cell_type": "code", "execution_count": 3, "id": "cd5", "metadata": { "execution": { "iopub.execute_input": "2026-05-04T22:45:18.240322Z", "iopub.status.busy": "2026-05-04T22:45:18.240184Z", "iopub.status.idle": "2026-05-04T22:45:18.243496Z", "shell.execute_reply": "2026-05-04T22:45:18.243147Z" } }, "outputs": [ { "data": { "text/plain": [ "PosixPath('atmospair_sample.zarr')" ] }, "execution_count": 3, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# (a) local sample subset\n", "DATA = Path(\"atmospair_sample.zarr\")\n", "\n", "# (b) local full store\n", "# DATA = Path(\"atmospair.zarr\")\n", "\n", "# (c) stream directly from Hugging Face\n", "# DATA = \"hf://datasets/era5wrf/atmospair/atmospair_sample.zarr\"\n", "\n", "DATA" ] }, { "cell_type": "markdown", "id": "md6", "metadata": {}, "source": [ "## Open and inspect" ] }, { "cell_type": "code", "execution_count": 4, "id": "cd7", "metadata": { "execution": { "iopub.execute_input": "2026-05-04T22:45:18.244620Z", "iopub.status.busy": "2026-05-04T22:45:18.244551Z", "iopub.status.idle": "2026-05-04T22:45:18.769562Z", "shell.execute_reply": "2026-05-04T22:45:18.769032Z" } }, "outputs": [ { "data": { "text/html": [ "
<xarray.Dataset> Size: 1GB\n",
"Dimensions: (time: 248, era5_channel: 68, south_north: 112,\n",
" west_east: 112, wrf_channel: 45, west_east_stag: 112,\n",
" south_north_stag: 112)\n",
"Coordinates: (12/13)\n",
" * time (time) datetime64[ns] 2kB 2015-07-01 ... 2015-07-31T21:00:00\n",
" * era5_channel (era5_channel) int64 544B 0 1 2 3 4 5 6 ... 62 63 64 65 66 67\n",
" era5_pressure (era5_channel) float64 544B dask.array<chunksize=(68,), meta=np.ndarray>\n",
" era5_variable (era5_channel) <U26 7kB dask.array<chunksize=(68,), meta=np.ndarray>\n",
" XLAT (south_north, west_east) float32 50kB dask.array<chunksize=(112, 112), meta=np.ndarray>\n",
" XLAT_V (south_north_stag, west_east) float32 50kB dask.array<chunksize=(112, 112), meta=np.ndarray>\n",
" ... ...\n",
" XLONG_V (south_north_stag, west_east) float32 50kB dask.array<chunksize=(112, 112), meta=np.ndarray>\n",
" * wrf_channel (wrf_channel) int64 360B 0 1 2 3 4 5 6 ... 39 40 41 42 43 44\n",
" wrf_pressure (wrf_channel) float64 360B dask.array<chunksize=(24,), meta=np.ndarray>\n",
" wrf_variable (wrf_channel) <U26 5kB dask.array<chunksize=(24,), meta=np.ndarray>\n",
" XLAT_U (south_north, west_east_stag) float32 50kB dask.array<chunksize=(112, 112), meta=np.ndarray>\n",
" XLONG_U (south_north, west_east_stag) float32 50kB dask.array<chunksize=(112, 112), meta=np.ndarray>\n",
"Dimensions without coordinates: south_north, west_east, west_east_stag,\n",
" south_north_stag\n",
"Data variables:\n",
" era5 (time, era5_channel, south_north, west_east) float32 846MB dask.array<chunksize=(1, 68, 112, 112), meta=np.ndarray>\n",
" era5_center (era5_channel) float32 272B dask.array<chunksize=(68,), meta=np.ndarray>\n",
" era5_scale (era5_channel) float32 272B dask.array<chunksize=(68,), meta=np.ndarray>\n",
" era5_valid (time, era5_channel) bool 17kB dask.array<chunksize=(1, 68), meta=np.ndarray>\n",
" wrf (time, wrf_channel, south_north, west_east) float32 560MB dask.array<chunksize=(1, 45, 56, 56), meta=np.ndarray>\n",
" wrf_center (wrf_channel) float32 180B dask.array<chunksize=(24,), meta=np.ndarray>\n",
" wrf_scale (wrf_channel) float32 180B dask.array<chunksize=(24,), meta=np.ndarray>\n",
" wrf_valid (time) bool 248B dask.array<chunksize=(1,), meta=np.ndarray>| \n", " | channel_index | \n", "variable | \n", "pressure_level | \n", "center | \n", "scale | \n", "
|---|---|---|---|---|---|
| 0 | \n", "0 | \n", "t | \n", "0.0 | \n", "287.130524 | \n", "9.599604 | \n", "
| 1 | \n", "1 | \n", "t | \n", "1.0 | \n", "283.516174 | \n", "9.576634 | \n", "
| 2 | \n", "2 | \n", "t | \n", "2.0 | \n", "280.106903 | \n", "8.702713 | \n", "
| 3 | \n", "3 | \n", "t | \n", "3.0 | \n", "273.134033 | \n", "7.102574 | \n", "
| 4 | \n", "4 | \n", "t | \n", "4.0 | \n", "266.655945 | \n", "6.621786 | \n", "
| ... | \n", "... | \n", "... | \n", "... | \n", "... | \n", "... | \n", "
| 63 | \n", "63 | \n", "z_pl | \n", "11.0 | \n", "160372.375000 | \n", "2079.970459 | \n", "
| 64 | \n", "64 | \n", "z_pl | \n", "12.0 | \n", "202335.734375 | \n", "2018.924561 | \n", "
| 65 | \n", "65 | \n", "t2m | \n", "NaN | \n", "286.980408 | \n", "9.648900 | \n", "
| 66 | \n", "66 | \n", "u10 | \n", "NaN | \n", "0.942892 | \n", "2.931440 | \n", "
| 67 | \n", "67 | \n", "v10 | \n", "NaN | \n", "0.020502 | \n", "3.360456 | \n", "
68 rows \u00d7 5 columns
\n", "| \n", " | channel_index | \n", "variable | \n", "pressure_level | \n", "center | \n", "scale | \n", "
|---|---|---|---|---|---|
| 0 | \n", "0 | \n", "T2 | \n", "NaN | \n", "284.995850 | \n", "10.891022 | \n", "
| 1 | \n", "1 | \n", "U10 | \n", "NaN | \n", "0.677727 | \n", "3.221539 | \n", "
| 2 | \n", "2 | \n", "V10 | \n", "NaN | \n", "-0.049391 | \n", "3.498643 | \n", "
| 3 | \n", "3 | \n", "U | \n", "0.0 | \n", "0.809392 | \n", "3.776051 | \n", "
| 4 | \n", "4 | \n", "U | \n", "1.0 | \n", "1.177182 | \n", "4.810004 | \n", "
| 5 | \n", "5 | \n", "U | \n", "2.0 | \n", "1.470120 | \n", "5.548637 | \n", "
| 6 | \n", "6 | \n", "U | \n", "3.0 | \n", "1.723451 | \n", "6.060884 | \n", "
| 7 | \n", "7 | \n", "U | \n", "4.0 | \n", "1.960289 | \n", "6.417025 | \n", "
| 8 | \n", "8 | \n", "U | \n", "5.0 | \n", "2.202434 | \n", "6.667762 | \n", "
| 9 | \n", "9 | \n", "U | \n", "6.0 | \n", "2.483363 | \n", "6.844941 | \n", "
| 10 | \n", "10 | \n", "V | \n", "0.0 | \n", "0.005848 | \n", "4.069026 | \n", "
| 11 | \n", "11 | \n", "V | \n", "1.0 | \n", "0.163601 | \n", "5.336325 | \n", "
| 12 | \n", "12 | \n", "V | \n", "2.0 | \n", "0.273564 | \n", "6.256277 | \n", "
| 13 | \n", "13 | \n", "V | \n", "3.0 | \n", "0.351190 | \n", "6.852526 | \n", "
| 14 | \n", "14 | \n", "V | \n", "4.0 | \n", "0.414801 | \n", "7.201840 | \n", "
| 15 | \n", "15 | \n", "V | \n", "5.0 | \n", "0.483226 | \n", "7.382185 | \n", "
| 16 | \n", "16 | \n", "V | \n", "6.0 | \n", "0.574123 | \n", "7.449575 | \n", "
| 17 | \n", "17 | \n", "TK | \n", "0.0 | \n", "285.245911 | \n", "10.731544 | \n", "
| 18 | \n", "18 | \n", "TK | \n", "1.0 | \n", "285.329254 | \n", "10.574802 | \n", "
| 19 | \n", "19 | \n", "TK | \n", "2.0 | \n", "285.143402 | \n", "10.547438 | \n", "
| 20 | \n", "20 | \n", "TK | \n", "3.0 | \n", "284.810577 | \n", "10.556077 | \n", "
| 21 | \n", "21 | \n", "TK | \n", "4.0 | \n", "284.361481 | \n", "10.563418 | \n", "
| 22 | \n", "22 | \n", "TK | \n", "5.0 | \n", "283.832947 | \n", "10.551333 | \n", "
| 23 | \n", "23 | \n", "TK | \n", "6.0 | \n", "283.209839 | \n", "10.504847 | \n", "
| 24 | \n", "24 | \n", "QVAPOR | \n", "0.0 | \n", "0.007722 | \n", "0.005057 | \n", "
| 25 | \n", "25 | \n", "QVAPOR | \n", "1.0 | \n", "0.007487 | \n", "0.004966 | \n", "
| 26 | \n", "26 | \n", "QVAPOR | \n", "2.0 | \n", "0.007314 | \n", "0.004876 | \n", "
| 27 | \n", "27 | \n", "QVAPOR | \n", "3.0 | \n", "0.007157 | \n", "0.004781 | \n", "
| 28 | \n", "28 | \n", "QVAPOR | \n", "4.0 | \n", "0.007011 | \n", "0.004686 | \n", "
| 29 | \n", "29 | \n", "QVAPOR | \n", "5.0 | \n", "0.006867 | \n", "0.004592 | \n", "
| 30 | \n", "30 | \n", "QVAPOR | \n", "6.0 | \n", "0.006715 | \n", "0.004496 | \n", "
| 31 | \n", "31 | \n", "Z | \n", "0.0 | \n", "1567.967529 | \n", "1836.498413 | \n", "
| 32 | \n", "32 | \n", "Z | \n", "1.0 | \n", "2104.729980 | \n", "1833.161377 | \n", "
| 33 | \n", "33 | \n", "Z | \n", "2.0 | \n", "2739.828369 | \n", "1829.536011 | \n", "
| 34 | \n", "34 | \n", "Z | \n", "3.0 | \n", "3472.869385 | \n", "1825.880005 | \n", "
| 35 | \n", "35 | \n", "Z | \n", "4.0 | \n", "4303.501953 | \n", "1822.423218 | \n", "
| 36 | \n", "36 | \n", "Z | \n", "5.0 | \n", "5231.985840 | \n", "1819.470947 | \n", "
| 37 | \n", "37 | \n", "Z | \n", "6.0 | \n", "6306.720215 | \n", "1817.239746 | \n", "
| 38 | \n", "38 | \n", "WPD | \n", "0.0 | \n", "172.018723 | \n", "362.259369 | \n", "
| 39 | \n", "39 | \n", "WPD | \n", "1.0 | \n", "324.692261 | \n", "488.129272 | \n", "
| 40 | \n", "40 | \n", "WPD | \n", "2.0 | \n", "505.466492 | \n", "657.061035 | \n", "
| 41 | \n", "41 | \n", "WPD | \n", "3.0 | \n", "670.813538 | \n", "875.464722 | \n", "
| 42 | \n", "42 | \n", "WPD | \n", "4.0 | \n", "800.661682 | \n", "1095.526367 | \n", "
| 43 | \n", "43 | \n", "WPD | \n", "5.0 | \n", "895.937744 | \n", "1293.620117 | \n", "
| 44 | \n", "44 | \n", "WPD | \n", "6.0 | \n", "964.707214 | \n", "1466.284546 | \n", "