Oceanography Expert

---
name: oceanography-expert
version: 1.0.0
description: Expert-level oceanography covering physical, chemical, biological, and geological oceanography, ocean circulation, thermohaline circulation, tides, and ocean-climate interactions.
author: luo-kai
tags: [oceanography, ocean circulation, thermohaline, tides, marine chemistry]
---

# Oceanography Expert

## Before Starting
1. Physical, chemical, biological, or geological oceanography?
2. Deep ocean or coastal/shelf?
3. Observational or modeling focus?

## Core Expertise Areas

### Ocean Structure
Zones: epipelagic (0-200m), mesopelagic (200-1000m), bathypelagic (1000-4000m), abyssal (4000m+).
Thermocline: layer of rapid temperature decrease separating warm surface from cold deep water.
Halocline: layer of rapid salinity change.
Pycnocline: layer of rapid density change — stabilizes water column against mixing.

### Ocean Circulation
Surface currents: wind-driven, Ekman transport, geostrophic gyres.
Thermohaline circulation: density-driven deep circulation, global conveyor belt.
AMOC: Atlantic Meridional Overturning Circulation — critical for European climate.
Upwelling: cold nutrient-rich water rises, driven by Ekman divergence.
El Nino: weakening trade winds, warm water shifts east, global climate impacts.

### Chemical Oceanography
Major ions: chloride, sodium, sulfate, magnesium, calcium, potassium.
Dissolved gases: oxygen (biological consumption), CO2 (carbonate system), N2.
Ocean acidification: CO2 absorption lowers pH, impacts carbonate organisms.
Nutrient cycles: nitrogen, phosphorus, silicon — limit primary production.

### Tides
Tidal forcing: gravitational pull of Moon and Sun on ocean water.
Spring tides: Sun and Moon aligned, larger range.
Neap tides: Sun and Moon at right angles, smaller range.
Tidal constituents: M2 (semidiurnal), K1 (diurnal), harmonic analysis.

## Best Practices
- Correct for tidal signal when analyzing sea level records
- Account for freshwater inputs in coastal salinity analysis
- Use Argo float data for subsurface temperature and salinity profiles
- Consider seasonal thermocline in productivity studies

## Common Pitfalls
| Pitfall | Fix |
|---|---|
| Confusing upwelling and downwelling | Upwelling brings nutrients up, increases productivity |
| Ignoring seasonal mixed layer depth | Mixed layer depth varies greatly by season |
| Confusing La Nina with El Nino | Opposite phases of ENSO cycle |
| Missing buoyancy flux in circulation | Both heat and freshwater affect density |

## Related Skills
- meteorology-expert
- marine-biology-expert
- climatology-expert