Day Ten, March 3, The land-sea breeze, a loud male singer in rough seas, and a trip to Islas Paridas
We are fortunate that the Gulf of Chiriquí is situated in a wind shadow while the Gulf of Panama to the east and the gulfs of Papagayo and Tehuantepec to the west endure sustained strong winds this time of the year.
Chiriquí is located in a shadow of relative calm, while the gulfs of Panama to the east and Papagayo to the west endure sustained “gap winds” crossing from the Caribbean through mountain gaps this time of the year. Image from https://earth.nullschool.net/#current/wind/surface/level/orthographic=-82.62,6.44,2242/loc=-82.312,8.192
However, the high pressure that dominates over Central America this time of year means that a local land-sea breeze develops twice a day very predictably. Like clockwork every morning around 7:30 am we get a breeze from land and around 3:00 pm we get an ocean breeze. This morning the breeze got a little intense while we were on transit to the the Islas Paridas for a survey there so we thought we were going to have to abandon that plan and return to the Secas. But not before doing an acoustic station with our hydrophone. As luck would have it, the song of a male humpback whale came very loudly through our earphones (it probably was within a few hundred meters from us). With a mix of excitement and disappointment (as we knew we would not be able to do much work with this whale in rough seas) we sat still, waiting for it to come to the surface so that we could at least catch a glimpse. But it stopped singing and we were unable to locate it visually at the surface among the white caps, so after about 45 min we decided to move on.
But by then the breeze had quieted down and Chanin, our captain, decided we could resume our original plan to survey the Paridas. We plied these waters in excellent weather conditions but without sign of humpback whales.