Moving 10-years analysis of nitrite at Mediterranean Sea for each season :

- winter (January-March),

- spring (April-June),

- summer (July-September),

- autumn (October-December).

Every year of the time dimension corresponds to the 10-year centered average of each season.

Decades span from 1965-1974 until 2004-2013.

Observational data span from 1961 to 2013.

Depth range (IODE standard depths): -1500.0, -1400.0, -1300.0, -1200.0, -1100.0, -1000.0, -900.0, -800.0, -700.0, -600.0, -500.0, -400.0, -300.0, -250.0, -200.0, -150.0, -125.0, -100.0, -75.0, -50.0, -30.0, -20.0, -10.0, -5.0, -0.0.

Data Sources: observational data from SeaDataNet/EMODNet Chemistry Data Network.

Description of DIVA analysis: Geostatistical data analysis by DIVA (Data-Interpolating Variational Analysis) tool. Profiles were interpolated at standard depths using weighted parabolic interpolation algorithm (Reiniger and Ross, 1968). GEBCO 1min topography is used for the contouring preparation. Analyzed filed masked using relative error threshold 0.3 and 0.5.

DIVA settings: A constant value for signal-to-noise ratio was used equal to 3. Correlation length was optimized and filtered vertically and a seasonally-averaged profile was used.

Logarithmic transformation applied to the data prior to the analysis.

Background field: the data mean value is subtracted from the data.

Detrending of data: no.

Advection constraint applied: no.

Originators of Italian data sets-List of contributors:

o Brunetti Fabio (OGS)

o Cardin Vanessa, Bensi Manuel doi:10.6092/36728450-4296-4e6a-967d-d5b6da55f306

o Cardin Vanessa, Bensi Manuel, Ursella Laura, Siena Giuseppe doi:10.6092/f8e6d18e-f877-4aa5-a983-a03b06ccb987

o Cataletto Bruno (OGS)

o Cinzia Comici Cinzia (OGS)

o Civitarese Giuseppe (OGS)

o DeVittor Cinzia (OGS)

o Giani Michele (OGS)

o Kovacevic Vedrana (OGS)

o Mosetti Renzo (OGS)

o Solidoro C.,Beran A.,Cataletto B.,Celussi M.,Cibic T.,Comici C.,Del Negro P.,De Vittor C.,Minocci M.,Monti M.,Fabbro C.,Falconi C.,Franzo A.,Libralato S.,Lipizer M.,Negussanti J.S.,Russel H.,Valli G., doi:10.6092/e5518899-b914-43b0-8139-023718aa63f5

o Celio Massimo (ARPA FVG)

o Malaguti Antonella (ENEA)

o Fonda Umani Serena (UNITS)

o Bignami Francesco (ISAC/CNR)

o Boldrini Alfredo (ISMAR/CNR)

o Marini Mauro (ISMAR/CNR)

o Miserocchi Stefano (ISMAR/CNR)

o Zaccone Renata (IAMC/CNR)

o Lavezza, R., Dubroca, L. F. C., Ludicone, D., Kress, N., Herut, B., Civitarese, G., Cruzado, A., Lefèvre, D., Souvermezoglou, E., Yilmaz, A., Tugrul, S., and Ribera d'Alcala, M.: Compilation of quality controlled nutrient profiles from the Mediterranean Sea, doi:10.1594/PANGAEA.771907, 2011.