Il Nam Kim. Department of Marine Science. University o

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EAST SEA STUDY
Implication of biogeochemical change driven by
global warming in the East Sea
Il Nam Kim
Department of Marine Science University of Texas
at Austin
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• INTRODUCTION
• BACKGROUND
• MATERIAL METHOD
• RESULTS
• CONCLUSION

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• INTRODUCTION

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The East Sea
? Study area
depth (m)

• 17 June 21 July
• 22 July 11 August

? a semi-closed marginal sea
? frequently referred to as miniature
ocean
? The maximum depth 4,049m
average depth 1,600m
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Dissolved Oxygen distribution at 1000m
Talley et al. 2006
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Warming evidences
? Temperature changes
Sea Surface Temp.
Vladivostok
Min and Kim, 2006
Kim et al., 2004
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? Oxygen changes
box modeling
Kang et al., 2004
Kim et al., 2001
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• BACKGROUND

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Denitrification
? In the presence of oxygen
? nitrification (NH4 ? NO2- ? NO3-)
? In the absence of oxygen
? denitrification (NO3- ? NO2- ? N2O/N2)
Sarmiento and Gruber, 2006
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? The major areas
The Arabian Sea
Devol, 1978
Hupe and Karstensen, 2000
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• MATERIAL

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Study Map
200 m
300 m
? Cruise CREAMS II expedition (1999)
? Parameters used T, S, DO, nutrients, TAlk,
DIC lat,
long, depth (300m)
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• METHOD

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Linear Inverse Mixing Model
? Model equations
Hupe and Karstensen 2000
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? Matrix form
A
x
d
R
-


Kim and Lee (2004) TMW (Tsushima Middle
Water) LCW (Liman Cold Water) ESIW (East Sea
Intermediate Water) ESPW (East Sea Proper Water)
known
known
unknown
unknown

• A source water types
• x mixing ratio
• d observed data
• R residual

? rD (Gruber and Sarmiento 1997)
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? Redfield ratios
? Solution
? MATLAB is available to calculate non-negative
solutions ? function of NNLS
? Weights
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• RESULTS I

- some evidences
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NP ratio
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Vertical profiles of NO3-, NO2-, O2, and N/P
ratio
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• RESULTS II

- linear inverse modeling
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Expected denitrification locations
? CASE 1
? CASE 2
? CASE 3
? CASE 4
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Vertical profiles of ?Ndeni
? CASE 1
? CASE 2
? CASE 3
? CASE 4
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How to derive the unit of time ?
? Estimation of pseudo-age using oxygen
? Example
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Horizontal distributions of ?Ndeni - CFCs
? CASE 1
? CASE 2
(µmol/m2day)
? CASE 3
? CASE 4
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Horizontal distributions of ?Ndeni - MBBM
? CASE 1
? CASE 2
(µmol/m2day)
? CASE 3
? CASE 4
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SUMMARY
Area 7.0926e3 km2
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• RESULTS III

- feedback loop
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The feedback loop based on biogeochemical
changes
Global Warming ?
Water formation ?
SST ?
Gamo (1999)
Gamo (1999)
Gamo et al. (2001)
Min and Kim (2006)
Kang et al. (2003b)
Chae et al. (2005)
Postlethwaite et al. (2005)
POSITIVE
low Oxygen Environment ?
Denitrification ?
N2O ?
Kim and Kim (1996)
?
Chen et al. (1999)
Kim et al. (2001)
Kang et al. (2004)
Kim et al. (2004)
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• CONCLUSION

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• The denitrification in the East Sea is estimated
  
• approximately to be 9 to 16 µmolm-2d-1
  through the
• linear mixing inverse model.
• New finding ? vs Warming event ?
• Therefore, we need to have deep concern about
  the
• phenomenon that is occurring though the
  oxygen
• content high. It might be a signal of
  global warming.

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Thank you for your time !