Archive for August 7th, 2011

Mystery Eddy

Sunday, August 7th, 2011

Good Afternoon everybody,


Well, it looks like Challenger has succumbed to a mysterious eddy that we did not think would have as much of an effect on us as it has.

As of yesterday, the general path of the currents seen in both the hycom model and the model provided to us by our good friends at ULPGC both showed currents flowing in a south-easterly direction, while Challenger has been reporting the currents moving in a 180° difference to the North West.  Today, the ULPGC model continues to show the same flow, while now the hycom is agreeing more closely with the currents that Challenger is reporting.

Fig. 1: SSHa with Current Vectors from ULPGC

In Figure 1, there shows that there is a difference in sea level to the south west of Challenger, but the currents show that there is a strong south east movement in our vicinity.

Fig. 2: Location of a cold core eddy to the South West

Fig. 3: HYCOM model of currents and Sea Surface Height

Figures 2 & 3 show today's imagery from ULPGC and HYCOM respectfully.  Although the eddy in question is not very clear in the SSH model, the currents do show a slight circular movement to show where the eddy lies, while the ULPGC model shows currents moving in a clear south east direction.   This discrepancy may be due to only receiving daily updates from both models, and with the most recent storm that has going through, I am sure the seas are all jumbled up.

Fig. 4: The 18 (?) storm Challenger has flown through

Oceanweather's wave forecast also gives us some insight on how the storms are effecting the area:

Fig. 5: Oceanweather's wave forcast for today

For now, we will wait to see where we surface to see how the current conditions are effecting our flight.  When we surface, if it looks like we are being dragged too far to the west, we may change the way point to try and follow a path along these lines:

Fig. 6: Possible path for Challenger 1 to follow. Depicted in both the ULPGC and HYCOM model respectively

Stay tuned for tomorrows update!