ROMS Model

Data on sea level anomaly (SLA), mixed layer depth (MLD), and temperature, salinity, and current velocity were obtained at 3 different depths (surface, below MLD, and bottom) from a Regional Ocean Modelling System (ROMS) model developed by Al Hermann and colleagues (Hermann et al. 2002; Hermann and Stabeno 1996) for the northern Gulf of Alaska. The model uses a rotated coordinate grid with a nominal resolution of 3×3 km2. The data presented are based on a run for the 2001 calendar year, obtained as NetCDF files.

The data are provided as a series of 28 tables in an MS Access database. Each table is comprised of 230,400 records, each representing a model point. Each record contains its geographic coordinate, and a value for all the variables for the specific time period. The tables contain one column per attribute. The column headers are described below. The variables obtained from the ROMS model (Table 1) were provided as 2-week averages for the year 2001 (Table 2).

Table 1: Date ranges for the 2-week averages obtained from the Hermann circulation model output. 

Variable Description
GridID, id GridID: The link to the study area grid; id: The internal ROMS identifier.
lon, lat Geographic coordinates to 2 decimal places.
mask Marine areas masked as valid (1) or invalid (0) based on flags in the velocity fields. The delivered file contains only the valid points, and therefore all values should be 1.
SLA Sea level anomaly (cm)
MLD Mixed layer depth as calculated algorithmically by the ROMS model.
Dmld Depth of model layer below the calculated mixed layer depth.
Tsurf, Tbot, Tmld Temperature (°C) at surface, bottom, and depth below MLD.
Ssurf, Sbot, Smld Salinity (psu) at surface, bottom, and depth below MLD.
Usurf, Vsurf, Wsurf
Ubot, Vbot, Wbot
Uamld, Vamld, Wamld,
Ubmld, Vbmld, Wbmld
Velocity components (U, V, W) at surface, bottom, and at levels both above (amld) and below (bmld) the MLD model level. Velocities are in m/s, but note that vertical (W) velocities are several orders of magnitude smaller.

Table 2: Date ranges for the 2-week averages obtained from the Hermann circulation model output.

Period

Start

End

Period

Start

End

1

2000-12-14

2000-12-27

15

2001-06-28

2001-07-11

2

2000-12-28

2001-01-10

16

2001-07-12

2001-07-25

3

2001-01-11

2001-01-24

17

2001-07-26

2001-08-08

4

2001-01-25

2001-02-07

18

2001-08-09

2001-08-22

5

2001-02-08

2001-02-21

19

2001-08-23

2001-09-05

6

2001-02-22

2001-03-07

20

2001-09-06

2001-09-19

7

2001-03-08

2001-03-21

21

2001-09-20

2001-10-03

8

2001-03-22

2001-04-04

22

2001-10-04

2001-10-17

9

2001-04-05

2001-04-18

23

2001-10-18

2001-10-31

10

2001-04-19

2001-05-02

24

2001-11-01

2001-11-14

11

2001-05-03

2001-05-16

25

2001-11-15

2001-11-28

12

2001-05-17

2001-05-30

26

2001-11-29

2001-12-12

13

2001-05-31

2001-06-13

27

2001-12-13

2001-12-26

14

2001-06-14

2001-06-27

28

2001-12-27

2002-01-09

 

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