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WP2: Data products generation in Mediterranean Sea EMODNET Chemistry Data Products, Experts Workshop Split (Croatia), 17-18 June 2014 Sissy Iona, HCMR-HNODC.

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Presentation on theme: "WP2: Data products generation in Mediterranean Sea EMODNET Chemistry Data Products, Experts Workshop Split (Croatia), 17-18 June 2014 Sissy Iona, HCMR-HNODC."— Presentation transcript:

1 WP2: Data products generation in Mediterranean Sea EMODNET Chemistry Data Products, Experts Workshop Split (Croatia), 17-18 June 2014 Sissy Iona, HCMR-HNODC

2 Outline  Regional data processing and QC  Data aggregation  Products generation-Diva Analysis

3 Regional pool  Current chemical data availability :  29.583 stations (of vertical profiles and time series)  231 parameters  25 Organizations/NODCs from 12 countries An example below of grouping of phosphate data (different methods, instruments, names, usage codes, units)

4 Data processing – QA/QC (1/2)  Use of Ocean Data View tool  We keep only the “good” originator’s data and apply additional QC checks  Create Individual collections for each initial parameter: 1. Perform QC (e.g. scatter plots and range checks) 2. Remaining errors flagged from “good” to “bad” (e.g. negative values, default values, etc) 3. Derived parameters prepared -for conversion to preferred products units (after step 1,2) 4. Each initial parameter and derives exported in separate ODV spreadsheets (export only “good “ data)

5 Data processing – QA/QC (2/2)  Reports of QC flag changes & format corrections were kept and sent to data originators/providers  No duplicates checks (was done before from SDN/MyOcean)  Units conversion:  PHOS/NO2/NO2+NO3/NO3/NH4 in µg/l converted in µmol/l by division by the atomic weight of phosphorus/nitrogen (most likely be µg N/l)  SiO4 data in µg/l converted using the molecular weight of the compound (from collocated comparisons)  µmol/kg converted to µmol/l automatically by ODV

6 Data aggregation  The good & clean data of previous step 4 are finally merged at the first 5 priority data products:  NH4, NO2, NO3, NOX (NO2+NO3), PO4, SiO4  in the preferred unit [µmol/l]  4 digits  SeaDataNet QC flag scale

7 QC of aggregated data  QC of previous steps (1,2) are repeated for any remaining errors  Information related with the data origin (e.g. LOCAL_CDI_ID and EDMO ) kept in the final aggregated data sets for further contact with the originators if necessary during the next stages of the analysis

8 Nutrients Data Ammonium, 12706 vertical profiles, 1970 - 2013 NO2+NO3, 3821 vertical profiles, 1979 - 2012

9 Nutrients Data Nitrate, 20246 vertical profiles, 1961 - 2013 Nitrite, 20820 vertical profiles, 1961 - 2013

10 Nutrients Data Phosphate, 23535 vertical profiles, 1952 - 2013 SiO4, 19892 vertical profiles, 1957 - 2013

11 Some scatter plots  Mediter., PO4  Mean: 0.162±0.254  Min: 0  Max: 17.013  130566 total meas.,  Summer: 45632 meas  Winter: 31702meas

12 Some scatter plots  Mediter., PO4  Mean: 0.162±0.254  Min: 0  Max: 17.013  130566 total meas.,  Summer: 45632 meas  Winter: 31702 meas

13 Some scatter plots  Adriatic, SiO4  Mean: 4.566±6.621  Min: 0  Max: 361.01  29691 total meas.,  Summer: 9191 meas  Winter: 6531 meas

14 Some scatter plots  Adriatic, SiO4  Mean: 4.566±6.621  Min: 0  Max: 361.01  29691 total meas.,  Summer: 9191 meas  Winter: 6531 meas

15 Exclude zeros (~6%) from DIVA analysis ? total meas.zerosDefault flaggedNegatives PO41236677933123317 SiO411909113745 NO3117006101144044 NH4487042600766 NO2334505166346 NOx2016480 Total46208227187954407 Results of QC

16  4 MSFD regions in Mediterranean  First results in Adriatic and Western Med  Nitrates, Phosphates, Silicates, NH4 (not shown here) Diva Analysis

17 Analysis & errors fields  We will mask areas of poor data coverage

18 Analysis & errors fields  Disregard these areas also?

19 Other results

20 Detection of trends  10 years moving windows (or other time frame) to reveal long term variabilities  Centered in the middle of the decade  1970 until 1979 as 1975  1971 until 1980 as 1976  ….  Seasonal Analysis  January to March as winter  April to June as spring  ….  Reference field  Climatic seasonal from all available years (with detrending for removal of uneven spatial distribution in time)  Without detrending

21 Mean: 0.6000 Std: 0.0736 Detection of trends Mean summer NO3 at first 10 m, over the area N43.5-46, E12-15


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