Modeled vertical carbon and nitrogen fluxes in waters of Namibia

Modeled vertical Carbon and Nitrogen fluxes in waters off Namibia N. Osma , L. Postel , I. Fernández-Urruzola, A. Herrera, M. Gómez and T. T. Packard Northern Benguela upwelling: Driving forces and ecosystem responses 18 – 20 September 2012, IOW Warnemünde, Germany Benguela Upwelling MSM 18/5 I. Mooring stations, NAM006 & NAM011 II. 3 Sections 12 ST & 1 Section 21 ST NAM006 NAM011 I. Moorings Stations NAM006 Date: 09/06/2011 Max. depth: 192 m. Mooring depth: 170 m. NAM011 Dates: 09/07/2011 and 09/17/2011 Max. depth: 395 m. Mooring depth: 330 m. NAM006 NAM011 Sampling Methodology Microplankton 9 - 10 depths with the Rosette 4 - 6 liters of SW filtered on board Filters frozen on liquid N2 I. Mooring stations Zooplankton 7 depths with the Multinet Size fractionation on board Cryovials frozen on liquid N2 Back at lab, ETS and GDH activities (Packard et al., 1971; Bidigare and King, 1981) Protein content (Lowry, 1951) Results I. Mooring stations At the 3 stations, the b-value is higher in zooplankton than in microplankton. NAM006 ♦ Microplankton ♦ Zooplankton RNH4+ = 6.0407z-0.618 R² = 0.9902 RNH4+ = 1.3359z-0.613 R² = 0.6187 0 50 100 150 200 0,0 0,2 0,4 0,6 0,8 1,0 DEPTH (m) NH4+ EXCRETION (μmol NH4+·h-1·m-3) RCO2 PRODUCTION (μmol CO2·h-1·m-3) RCO2 = 1724.8z-1.257 R² = 0.8906 RCO2 = 32.61z-0.604 R² = 0.9344 0 50 100 150 200 0 5 10 15 20 25 30 35 Results I. Mooring stations NAM011 (7 Sept.) ♦ Microplankton ♦ Zooplankton NH4+ EXCRETION (μmol NH4+·h-1·m-3) RCO2 PRODUCTION (μmol CO2·h-1·m-3) RNH4+ = 13.988z-0.786 R² = 0.8847 RNH4+ = 6.2352z-0.741 R² = 0.7017 0 100 200 300 400 500 600 0,0 0,2 0,4 0,6 0,8 1,0 1,2 DEPTH (m) RCO2 = 5373.3z-1.548 R² = 0.7936 RCO2 = 30.21z-0.472 R² = 0.8979 0 100 200 300 400 500 600 0 5 10 15 At the 3 stations, the b-value is higher in zooplankton than in microplankton. Results I. Mooring stations NAM011 (17 Sept.) ♦ Microplankton ♦ Zooplankton NH4+ EXCRETION (μmol NH4+·h-1·m-3) RCO2 PRODUCTION (μmol CO2·h-1·m-3) RNH4+ = 7.543z-0.633 R² = 0.87 RNH4+ = 0.9606z-0.237 R² = 0.8919 0 100 200 300 400 500 600 0,0 0,5 1,0 1,5 DEPTH (m) RCO2 = 1393.5z-1.378 R² = 0.863 RCO2 = 4.7737z-0.14 R² = 0.8831 0 100 200 300 400 500 600 0 10 20 30 40 At the 3 stations, the b-value is higher in zooplankton than in microplankton. Results I. Mooring stations Calculate the definite integral from the different depths (za) to the sea floor (zs) Nitrogen Fn = ∫RNH4+ dz = ∫R0z-b Fn = (R0/(1-b))*(zs(1-b) - za(1-b) ) Carbon Fc = ∫RCO2 dz = ∫R0z-b Fc = (R0/(1-b))*(zs(1-b) - za(1-b) ) Plot Fn and Fc versus depth Results Moorings stations Nitrogen Zooplankton Microplankton ● NAM006 ● NAM011 (7 Sept.) ● NAM011 (17 Sept.) 0 100 200 300 400 500 600 0 1000 2000 3000 N - FLUX (μmol N·d-1·m-2) Fn= 204631 z -1.405 Fn= 93320 z -0.996 Fn= 84276 z -0.93 0 100 200 300 400 500 600 0 1000 2000 3000 Fn= 2913 .1z -0.804 Fn= 11566 z -0.735 Fn= 12807 z -0.568 DEPTH (m) N - FLUX (μmol N· d-1 · m-2) II. Sections 0 500 1000 1500 2000 NAM007 Fn= 10636 z -0.735 NAM009 Fn= 10292 z -0.643 N - FLUX (μmol N · d-1 · m-2) Results: Nitrogen II. Sections NAM017 Fn= 10197 z -0.403 NAM018 Fn= 14682 z -0.393 0 1000 2000 3000 4000 N - FLUX (μmol N · d-1 · m-2) Results: Nitrogen II. Sections NAM022 Fn= 14414 z -0.464 NAM024 Fn= 8862.8 z -0.469 0 600 1200 1800 2400 3000 N - FLUX (μmol N · d-1 · m-2) Results: Nitrogen II. Sections Zooplankton associated N flux profile along the section Results: Nitrogen Zooplankton associated C fluxes, based on average values of ETS activities on the 4 sections. Comparison of 4 areas within the section. NAM002 & 003 NAM007 NAM017 NAM022 & 023 II. Sections: Carbon II. Sections NAM002 Fc= 114045 z -1.203 NAM003 Fc= 126793 z -1.069 C - FLUX 0 2000 4000 6000 8000 (μmol C · d-1 · m-2) Results: Carbon II. Sections NAM007 Fc= 116264 z -0.679 0 5000 10000 15000 20000 (μmol C · d-1 · m-2) C - FLUX Results: Carbon II. Sections NAM017 Fc = 90231 z -1.098 0 2000 4000 6000 C - FLUX (μmol C · d-1 · m-2) Results: Carbon II. Sections NAM022 Fc= 60173 z -0.693 NAM023 Fc= 75534 z -0.66 0 2500 5000 7500 10000 C - FLUX (μmol C · d-1 · m-2) Results: Carbon II. Sections Zooplankton associated C flux profile along the section Results: Carbon Results I. Moorings stations Carbon Zooplankton ■ Mooring data ■ C flux model Microplankton 0 500 1000 1500 2000 2500 NAM006 NAM011 (7 Sept.) NAM011 (17 Sept.) μmol C · d-1 · m-2 0 1000 2000 3000 4000 5000 NAM006 NAM011 (7 Sept.) NAM011 (17 Sept.) μmol C · d-1 · m-2