Sampling Requirements for the Global Ocean

Code

Application

Variable

Hor. Res.

Vert. Res.

Time Res.

#samples

Accuracy

A

NWP, climate, mesoscale ocean

Remote SST

10 km

-

6 h

1

0.1-0.3EK

B

Bias correction, trends

In situ SST

500 km

-

1 week

25

0.2-0.5EC

C

Climate variability

Sea surface salinity

200 km

-

10 day

1

0.1

D

Climate prediction and variability

Surface wind

2E

-

1-2 day

1-4

0.5-1 m/s in components

E

Mesoscale, coastal

Surface wind

50 km

-

1 day

1

1-2 m/s

F

Climate

Heat flux

2E x 5E

-

month

50

Net: 10 W/m²

G

Climate

Precip.

2E x 5E

-

daily

several

5 cm/month

H

Climate change trends

Sea level

30-50gauges + GPS with altimetry, or several 100 gauges + GPS

-

monthly means

1 cm, giving 0.1 mm/yr accuracy trends over 1-2 decades

I

Climate variability

Sea level anomalies

100-200 km

-

10-30 days

~ 10

2 cm

J

Mesoscale variability

Sea level anomalies

25-50 km

-

2 days

1

2-4 cm

K

Climate, short-range prediction

sea ice extent, concentration.

~ 30 km

-

1 day

1

10-30 km
2-5%

L

Climate, short-range prediction

sea ice velocity

200 km

-

Daily

1

cm/s

M

Climate

sea ice volume,

    thickness

500 km

-

monthly

1

~ 30 cm

N

Climate

surface pCO₂

25-100 km

-

daily

1

0.2-0.3 µatm

O

ENSO prediction

      T(z)

1.5E x 15E

15 m over

500 m

5 days

4

0.2EC

P

Climate variability

      T(z)

1.5E x 5E

~ 5 vertical. modes

1 month

1

0.2EC

Q

Mesoscale ocean

      T(z)

50 km

~ 5 modes

10 days

1

0.2EC

R

Climate

      S(z)

large-scale

~ 30 m

monthly

1

0.01

S

Climate, short-range prediction

  U(surface)

600 km

-

month

1

2 cm/s

T

Climate model valid.

      U(z)

a few places

30 m

monthly  means

30

2 cm/s