# 📐  L2 Spec — Numerical Weather Prediction Data Assimilation — Nominal + Mismatch Specs

**ID:** `L2-418-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-418`](/artifact/l1/L1-418)

> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.5 · **Delta tier:** 5
> **⛓ On-chain block:** 41555241

---

## 1. Domain Ω

**Type:** `range`

| Parameter | Unit | Range |
|---|---|---|
| Window hours | — | 3 – 12 |
| N observations | — | 100000 – 5000000 |
| Obs error ratio | — | 0.5 – 5.0 |
| Model resolution km | km | 2 – 50 |

## 2. Tolerance (ε)

**Type:** `fn`

```
0.3 + 0.2 * (model_resolution_km / 10) ** 0.2
```

## 3. Difficulty

| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |

## 4. Fingerprint

`8e6d79470cf0349a2e59e8f746d3408222d28d01003195b0136b574f51dcfd79`

## 5. On-chain Registration

- **Chain hash:** `0xde48e7591498d6a945d1ad86f55a3e8012ac1c5a1cb16bac77cebd7c6eac7510`
- **Chain tx hash:** `0x203654f0f24ef036e96ce81bacb4061e8921836d4b788b2b80601bc38b5eba05`
- **Chain block:** `41555241`

---

## File Mapping

This bundle consists of: `L2-418-001.md`, `L2-418-001.json`.

| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-418-001.md` | Source of truth — edit this | Human or LLM |
| `L2-418-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |

**Prompt for your LLM after editing this Markdown:**

> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.

_This Markdown was auto-synthesized from the catalog row for `L2-418-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._