68 lines
2.1 KiB
JSON
68 lines
2.1 KiB
JSON
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{
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"title": "Storm Lake Frost-Depth Calculator",
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"author": "Barbara Cintron",
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"location": "Storm Lake, Iowa, USA",
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"model": {
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"name": "Stefan Phase-Change Approximation",
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"equation": "D = K(m) × √(HDD)",
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"variables": {
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"D": {
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"symbol": "D",
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"name": "frost depth",
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"unit": "centimeters",
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"description": "Maximum vertical penetration of ice front into soil matrix"
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},
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"K": {
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"symbol": "K(m)",
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"name": "conductivity factor",
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"unit": "cm/(°C·day)^0.5",
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"formula": "2.2 + (m - 5) × (2.0 / 40)",
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"bounds": {
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"min": {"moisture_percent": 5, "K_value": 2.2, "soil_type": "dry sand"},
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"max": {"moisture_percent": 45, "K_value": 4.2, "soil_type": "saturated clay"}
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},
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"storm_lake_typical": {
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"moisture_percent": 22,
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"K_value": 3.82
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}
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},
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"HDD": {
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"symbol": "HDD",
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"name": "heating degree-days",
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"unit": "°C·days",
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"base_temperature": "0°C",
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"calculation": "Σ(max(0, T_base − T_daily))",
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"typical_iowa_jan_mar": {
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"min": 4500,
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"max": 6800
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}
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}
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}
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},
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"citations": [
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{
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"wikidata": "Q14524610",
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"slug": "heating-degree-day",
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"concept": "sum of temperature deficits driving phase change"
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},
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{
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"wikidata": "Q3775789",
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"slug": "stefan-problem",
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"concept": "moving boundary solution for solidification fronts"
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},
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{
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"wikidata": "Q487005",
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"slug": "thermal-conductivity",
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"concept": "material property scaling heat flux through soil matrix"
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}
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],
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"operational_thresholds": [
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{"depth_cm": 30, "classification": "light freeze", "action": "snow cover sufficient"},
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{"depth_cm": 60, "classification": "moderate freeze", "action": "mulch perennials, 0.9m pipe depth"},
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{"depth_cm": 120, "classification": "deep freeze", "action": "biennial dormancy, 1.5m foundations"},
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{"depth_cm": 200, "classification": "critical freeze", "action": "geothermal displacement required"}
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],
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"version": "1.0.0",
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"compiled": "2026-07-17T06:00:00Z"
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}
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