Adinrichs et al. 
DD. 
7.05 
D.1 
3.05 
A 
KNSCvV2 
3= a9101)7 
-0.01+0.2 
0 
ATI°C] 
a) 
KNSCv2 
Z= 352002 
» -0.00+0.1 
DD. 
D.05 
- 
J 
0.1 
0.05 
Sa] 
BALTIC 
Z = 207508 
| 0.01+0.36[ 
0 
ATIT°C] 
IE 
BALTIC 
| X = 19913 
0.02+0.12 
| 
Baltic and North Seas Climatology 
0.1 
CC 
BSRA 
3 = 439773 
-0.00+0.47' 
0.05 
I 
.L 
0 
ATT°C] 
F 
BSRA 
S = 384675 
0.05 * -0.01+0.21' 
0.1 
|) man“ 0 0° 
-0.5 0 0.5 -0.5 0 0.5 -0.5 0 0.5 
AS[PSU] AS[PSU] AS[PSU] 
FIGURE 9 | Relative frequency distributions of absolute differences between the BNSC data product and KNSCv2 [temperature: (A) and salinity: (D)], the Baltic 
ATLAS [temperature: (B) and salinity: (E)] and BSRA [temperature: (C) and salinity: (F)]. Additional information are the number of collocated boxes (i.e., 4910187 in the 
case of KNSCV?} and the mean and standard deviation of the absolute differences. 
TABLE 4 | Dimensions of the BNSChydr and BNSCatm data products, 
Variable Explanation 
8NSChydr 
at 
Vector of latitude values defining the box center 
47.125°N—65,875°N, edge length 0.25°, length of vector: 76) 
Yector of longitude values defining the box center 
14.875°W—29.875°E, edge length 0.25°, length of vector: 180} 
Standard depth levels (0-4985 m, 5 m-distance up to 50 m depth, 
after that, continuous increase of distance bv 1m. 105 depth 
evels In total 
Zn 
depth 
BNSCatm 
at 
Vector of latitude values defining the box center 
47.5°N—65.5°N, edge length 1°, length of vector: 19} 
Vector of longitude values defining the box center 
14.5°W—30.5°E. edae lenath 1°, lenath of vector: 46) 
In 
well as in temperature. After that, the data density increases (see 
also Figure 1) and also the deeper layers are populated. 
Decadal Box Averages 
For the decades determined in section Creation of mean values, 
a temporal mean over the box averages is created together 
with the corresponding standard deviation. Every populated box 
is considered for this. An example, the decadal temperature 
mean of August, is shown in Figure 8A at 10m depth for the 
decade 1976-1985. 
To be able to estimate the representativeness of the temporal 
mean for the respective decade, further statistics are made 
available together with the decadal monthly mean and the 
corresponding standard deviation. This is, on the one hand, the 
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number of years that went into the decadal monthly mean with 
the maximum number consequently accounting to 10. On the 
other hand, information about the coverage of the time window 
of the decade is provided. For this purpose, an average and 
corresponding standard deviation are calculated of the years that 
contribute to the decadal mean. This defines the temporal center 
and spread of the decadal box average. A decadal monthly mean, 
for which all of the 10 years contribute, yields a mean value of, 
for example, 1990.5 (for the decade 1986-1995) and a standard 
deviation of 3.0. 
interpolated Fields 
Based on the decadal box averages, as described in section 
Aorizontally interpolated fields, the interpolated fields of the 
decadal monthly means are created. An example is displayed 
in Figure 8B. Besides other statistical parameters that are not 
explicitly shown here, a relative interpolation error is made 
available and is shown for the example in Figure 8C. For 
the definition of the interpolation error, see Gouretski and 
Koltermann (2004). The relative interpolation error differs 
between 0 and 1 and should always be considered together with 
the interpolated field. It can be used to mask field values. One 
example would be to use only interpolated values that correspond 
to a relative interpolation error of < 0.5. 
Sensitivity Study 
'n contrast to the BNSCatm, the sensitivity study for BNSChydr 
was done on different depth horizons, thus yielding of up to 
105 different fluctuation ranges, depending on the region in 
focus. For the display of the results, Table 3 is restricted to 
three exemplary depth levels for each region for temperature 
Alb 2019 1 Valııme 7 1 Article 15%