Surface Pressure drift in BSH Floats

Surface Pressure drift in BSH Floats

0 20 40 60 80 100 120 140 160 180 200-30

-20

-10

0

10

20

30

40

50

147

148149 150

151 152153

169172173

289

290

291

298299

300301

302

2151

550

551

552

553 554555

556

10601061 10621547

1548155015511552155315541555158616371757175817691770177121442145

2146

2147214821492150215221532316231823192320325032513252325332543255327932803281328232833284603060316032 60296033 60356034603660476062

6063

60646200

6078

6202

6203

6204

6205

6075

6076

6077

6167

6168

6169617061866188618961906191

6192

6193621162636319632063216322 161721345748596768 697071727374757677

Cycle

Su

rfa

ce P

ress

ure

[db

ar]

All BSH floats

Paine and Amtec sensors

Druck sensor 2003-2007

Druck sensor 2008

0-1.1 dbar

Surface Pressure drift in BSH Nemo Floats

0 20 40 60 80 100 1200

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

16

1721

34

57

48

59

67

68

69 70

71

72

73

74

7576

77

Surface Pressure measurements from Nemo floats

Cycle

Su

rfa

ce P

ress

ure

[db

ar]

Surface pressure is measured after ascent and before descending

Only positive pressure readings are recorded

Negative pressure readings are truncated

CTD is in self correction mode (reset-offset)

Surface Pressure drift in BSH Nemo Floats: Effects of cumulative correction

0 20 40 60 80 100 120-2

-1

0

1

2

3

4

5

6

7

16

17

21

34

57

4859

6768

69

70

71

727374

757677

Cycle

Cu

mu

lativ

e s

urf

ace

pre

ssu

re [d

ba

r]Surface pressure measurements from Nemo floats, truncated negattive pressures fitted by noise