nutrients in the indian ocean - integration and …m. dileep kumar national institute of...
TRANSCRIPT
![Page 1: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/1.jpg)
Nutrients in the Indian Ocean
M. Dileep KumarNational Institute of Oceanography
Dona Paula, Goa, India
SIBER
![Page 2: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/2.jpg)
Nitrogen, phosphorus & silicateTrace metals
• Distribution• Processes• Driving forces
SIBER
Monsoon circulationPrimary ProductionNutrients – Nitrogen biogeochemistry
![Page 3: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/3.jpg)
Distance (km)
Dep
th (m
)D
epth
(m)
Meridional variability in nutrients – geographic domains
Monsoon GyreSouthernSubtropicalGyre
Polar
SIBER
![Page 4: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/4.jpg)
Zonal variability in nutrients
SIBER
![Page 5: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/5.jpg)
Monsoons as driving force
Monsoon forcing: North Indian Ocean
SIBER
![Page 6: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/6.jpg)
River discharges & differential vertical mixing
INDIANSUBCONTINENT
Bay ofBengal
ArabianSea
1.6x1012 m3/yWATER 0.3x1012 m3/y
1.4x109 tons/ySPM 0.2x109 tons/y
SIBER
![Page 7: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/7.jpg)
Primary Productivity map
Global Primary production Behrenfeld and Falkowski (1997)
SIBER
![Page 8: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/8.jpg)
Nitrate deficits, global significance of del N and N2O fluxes
Del N = 1/3 Global? N2O flux = ~8% Global
N2OO2
NO3
NO2
19oN, 67oE
N*Gruber &Sarmiento (2002)
NO3 DeficitCodispoti et al. (2001)
from Naqvi (2006)
Excess N2
SIBER
![Page 9: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/9.jpg)
Decoupled active denitrification region
Naqvi (1991)SIBER
![Page 10: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/10.jpg)
-O2: C: N: P Reference
138:106:16:1 Redfield et al (1963)
126:96:15:1 Sen Gupta & Naqvi (1984)172:119:14.9:1 Takahashi et al (1985)118:125:14.2:1 O2>10 μM; Millero et al (1998)145:42:6.3:1 O2<10 μM; Millero et al (1998)139:90:14.4:1 550-1200 m; Hupe & Karstensen (2000)152:107:14.9:1 1200-2000 m; Hupe & Karstensen (2000)Denitrification
130:94:10.3:1 (θ < 12oC) EQIO; Li & Peng (2002)Partial conversion of organic nitrogen to ………..
Redfield ratios – anomalies
SIBER
![Page 11: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/11.jpg)
Bange et al (2005)
Implications to mineral formation
Redfield ratios – phosphate accumulation in O2 deficient waters
Samples collected from < 200 m
SIBER
![Page 12: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/12.jpg)
Nitrate deficits in the East Indian Ocean ?
Kumar (2001)
SIBER
![Page 13: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/13.jpg)
Broecker et al. (1980)
Kumar & Li (1996)
North suppliesmaterials to theSouth Indian Ocean
SIBER
![Page 14: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/14.jpg)
How much do we know about forcings?
Inputs to North Indian Ocean (Naqvi, 2006)
River & groundwater 0.56Atmospheric deposition – trace metals 2.9Fixation 3.8Sedimentary fluxes ???Exchanges with marginal seas 0.7Vertical mixing – upwelling ???
SIBER
![Page 15: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/15.jpg)
Evaluation of nutrient supplies – rivers
1950 1960 1970 1980 1990 2000Year
0
4
8
12
N -
Fert
ilize
r use
d (1
06 ton
s)
0.8
1.2
1.6
2
2.4
2.8
3.2
Mar
ine
Fish
Cat
ch (1
06 ton
s)
Seitzinger et al. (2002)
Naqvi et al. (2000)
Kumar (2004)
SIBER
No reliable dataavailable for realistic estimates
![Page 16: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/16.jpg)
Goes et al. (2005) SIBER
Evaluation of nutrient supplies –Upwelling ……Eurasian Snow Cover !!!
![Page 17: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/17.jpg)
We have reasonable knowledge ondistributions….
BUT …….. very little on the• variability in abundances • quantitative nutrient transfers and
transformations
We NEED to have integrated time-seriesmeasurement systems strategically placed(Process expeditions-moorings-satellites)
SIBER
![Page 18: Nutrients in the Indian Ocean - Integration and …M. Dileep Kumar National Institute of Oceanography Dona Paula, Goa, India SIBER Nitrogen, phosphorus & silicate Trace metals •](https://reader034.vdocuments.net/reader034/viewer/2022050403/5f80f3344b9f68266c3e5567/html5/thumbnails/18.jpg)
Thank You!
SIBER