World Library  


Add to Book Shelf
Flag as Inappropriate
Email this Book

Estimating Mixed Layer Nitrate in the North Atlantic Ocean : Volume 6, Issue 5 (03/09/2009)

By Steinhoff, T.

Click here to view

Book Id: WPLBN0004005377
Format Type: PDF Article :
File Size: Pages 31
Reproduction Date: 2015

Title: Estimating Mixed Layer Nitrate in the North Atlantic Ocean : Volume 6, Issue 5 (03/09/2009)  
Author: Steinhoff, T.
Volume: Vol. 6, Issue 5
Language: English
Subject: Science, Biogeosciences, Discussions
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Historic
Publication Date:
2009
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

Citation

APA MLA Chicago

Oschlies, A., Körtzinger, A., Hartman, S. E., Friedrich, T., R. Wallac, D. W., & Steinhoff, T. (2009). Estimating Mixed Layer Nitrate in the North Atlantic Ocean : Volume 6, Issue 5 (03/09/2009). Retrieved from http://www.ebooklibrary.org/


Description
Description: Leibniz Institut für Meereswissenschaften (IFM-GEOMAR), Kiel, Germany. Here we present an equation for the estimation of nitrate in surface waters of the North Atlantic Ocean (40° N to 52° N, 10° W to 60° W). The equation was derived by multiple linear regression (MLR) from nitrate, sea surface temperature (SST) observational data and model mixed layer depth (MLD) data. The observational data were taken from merchant vessels that have crossed the North Atlantic on a regular basis in 2002/2003 and from 2005 to present. It is important to find a robust and realistic esitmate of MLD because the deepening of the mixed layer is crucial for nitrate supply to the surface. We compared model data from two models (FOAM and Mercator) with MLD derived from float data (using various criteria). The Mercator model gives a MLD estimate that is close to the MLD derived from floats. MLR was established using SST, MLD from Mercator, time and latitude as predictors. Additionally a neural network was trained with the same dataset and the results were validated against both model data as a ground truth and an independent observational dataset. This validation produced RMS errors of the same order for MLR and the neural network approach. We conclude that it is possible to estimate nitrate concentrations with an uncertainty of ±1.5 μmol L−1 in the North Atlantic.

Summary
Estimating mixed layer nitrate in the North Atlantic Ocean

Excerpt
Castellaro, S., Mulargia, F., and Kagan, Y.: Regression problems for magnitudes, Geophys. J. Int., 165, 913–930, doi:10.1111/j.1365-246X.2006.02955.x, 2006.; Bates, N. R.: Interannual variability of the oceanic {CO}2 sink in the subtropical gyre of the {N}orth {A}tlantic {O}cean over the last 2 decades, J. Geophys. Res., 112, C09013, doi:10.1029/2006JC003759, 2007.; Chierici, M., Olsen, A., Johannessen, T., Trina{ñ}es, J., and Wanninkhof, R.: Algorithms to estimate the carbon dioxide uptake in the northern North Atlantic using shipboard observations, satellite and ocean analysis data, Deep-Sea Res. II, 56, 630–639, 2009.; Cianca, A., Helmke, P., Mouri{ñ}o, B., Rueda, M. J., Llin{á}s, O., and Neuer, S.: Decadal analysis of hydrography and in situ nutrient budgets in the western and eastern North Atlantic subtropical gyre, J. Geophys. Res., 112, C07025, doi:10.1029/2006JC003788, 2007.; de Boyer Mont{égut}, C., Madec, G., Fischer, A. S., Lazar, A., and Iudicone, D.: Mixed layer depth over the global ocean: An examination of profile data and profile-based climatology, J. Geophys. Res., 109, C12003, doi:10.1029/2004JC002378, 2004.; de Co{ë}tlogon, G. and Frankignoul, C.: The persistence of Winter Sea Surface Temperature in the North Atlantic, J. Climate, 16, 1364–1377, 2003.; Dore, J. E., Houlihan, T., Hebel, D. V., Tien, G., Tupas, L., and Karl, D. M.: Freezing as a method of sample preservation for the analysis of dissolved inorganic nutrients in seawater, Mar. Chem., 53, 173–185, 1996.; Eden, C. and Oschlies, A.: Adiabatic reduction of circulation-related {CO}2 air-sea flux biases in a {N}orth {A}tlantic carbon-cycle model, Global Biogeochem. Cy., 20, GB2008, doi:10.1029/2005GB002521, 2006.; Emery, W., Brandt, P., Funk, A., and B{ö}ning, C.: A comparison of sea surface temperatures from microwave remote sensing of the Labrador Sea with in situ measurements and model simulations, J. Geophys. Res., 111, C12013, doi:10.1029/2006JC003578, 2006.; Koeve, W.: Wintertime nutrients in the Noth Atlantic – new approaches and implications for new production estimates, Mar. Chem., 74, 245–260, 2001.; Friedrich, T. and Oschlies, A.: Neural network-based estimates of N}orth {A}tlantic surface p{CO}2 from satellite data: A methodological study, J. Geophys. Res., 114, C03020, doi:10.1029/2007JC004646, 2009{a.; Friedrich, T. and Oschlies, A.: Basin-scale \it p}{CO}2 maps estimated from {ARGO float data – a model study, J. Geophys. Res., submitted, 2009{b}.; Garcia, H., Locarnini, R., Boyer, T., and Antonov, J.: Volume 4: Nutrients (phosphate, nitrate, silicate), in: World Ocean Atlas 2005, edited by Ed. NOAA Atlas NESDIS 64, U. G. P. O., S. Levitus, 396 pp., 2006.; Garside, C. and Garside, J. C.: Euphotic-zone nutrient algorithms for the NABE and EqPac study site, Deep-Sea Res.II, 42, 335–347, 1995.; Glover, D. M. and Brewer, P. G.: Estimates of wintertime mixed layer nutrient concentration in the North Atlantic, Deep-Sea Res., 35, 1525–1546, 1988.; Goes, J. I., Saino, T., Oaku, H., Ishizaka, J., Wong, C. S., and Nojiri, Y.: Basin scale estimates of sea surface nitrate and new production from remotely sensed sea surface temperature and chlorophyll, Geophys. Res. Lett., 27, 1263–1266, 2000.; Gonz{á}lez-D{á}vila, M., Santana-Casiano, J. M., and Gonz{á}lez-D{á}vila, E. F.: Interannual variability of the upper ocean carbon cycle in the northeast {A}tlantic {O}cean, Geophys. Res. Lett., 34, L07608, doi:10.1029/2006GL028145, 2007.; Hansen, H. and Koroleff, F.: Determination of nutrients, in: Methods of seawater analysis, edited by Grasshoff, K., Kremling, K., and Erhardt, M., Verlag Chemie, Weinheim, Germany, 159–228, 1999.; Hartman, S. E., Larkin, K. E., Lampitt, R. S., Lankhorst, M., and Hydes, D. J.: Seasonal and inter-annual biogeochemical variations at PAP (49°N, 16.5°W) 2003–2005 associated

 

Click To View

Additional Books


  • Estimating Carbon Emissions from African... (by )
  • Seasonal Survey of the Composition and D... (by )
  • Relative Effects of Precipitation Variab... (by )
  • Revisiting Mt. Kilimanjaro: Do N-alkane ... (by )
  • Imprint of a Dissolved Cobalt Basaltic S... (by )
  • Photoproduction of Ammonium in the South... (by )
  • Temperate Carbonate Cycling and Water Ma... (by )
  • After Trees Die: Quantities and Determin... (by )
  • Modelling Basin-wide Variations in Amazo... (by )
  • Governing Processes for Reactive Nitroge... (by )
  • Summer Upwelling at the Boknis Eck Time ... (by )
  • Modeling the Dynamic Chemical Interactio... (by )
Scroll Left
Scroll Right

 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.