Once you have selected the area for your image and processed it the way you prefer you can optionally add ocean surface current information. The current information will appear on your image as a series of black arrows. The direction of each arrow indicates the direction the current is running and the length of the arrow indicates its relative strength (i.e knots per hour).
9.1 Display Ocean Currents
| To display the currents for your selected area just click on the red Currents On/Off button to the left of the image. The current arrows will then be shown (See Fig 27 below).
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Fig 27
9.2 Read Current Information
| Step 1: |
To read the details for any current arrow in your image hold down the Ctrl and Shift buttons simultaneously on the keyboard and then click on the start of the arrow (the opposite end to the arrow head - See Fig 28 below) with the left mouse button.
Fig 28
A small box with details on the current arrow will open up in the top right corner of your image (See Fig 29 below). At the same time the colour of the particular current arrow that you are querying will change to Purple.
To see the details of another current arrow just repeat the same steps as above.
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Fig 29
| Step 2: |
To move the details box to another location in your image hold the Ctrl and Shift buttons simultaneously again and with the left mouse button click on the box, then with the mouse button still held down, drag the box to another location. To delete the box altogether hold down the Ctrl and Shift buttons simultaneously on the keyboard and then click anywhere in the image away from the box.
The details within the box (See Fig 30 below) indicate the speed of the current in knots per hour (e.g. 1.64 kts) and the compass direction in which the current is running (e.g 193.5 degrees). Also included are the vector components that make up the current (i.e the north, south, east and west components).
Fig 30
Also included in the details box for each current arrow is the geographical position of the current reading (i.e. lat/long in decimal degrees and degrees, minutes and seconds) and the date of the information. Note that the position, current speed and current direction all refer to the position at the start of the arrow where you clicked (i.e the end opposite the arrowhead). The current information is downloaded from NOAA each night at 7pm (AEST) and will always be a couple of days old. You can however look at the previous days information and monitor the changes that are occurring daily.
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Troubleshooter:
If you are clicking on the current arrow and the pop-up information box doesn't appear then it is likely that one of two things has happened, Firstly, perhaps you aren't clicking on the non-arrowhead end or secondly you have not clicked close enough to the start of the arrow. You should try again.
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