#6 DOG DAYS IN THE HORSE LATITUDES

From:  David Art[SMTP:SCI7@KNORR.WHOI.EDU]

Sent:    Sunday, July 01, 2001 4:17:44 PM

To:       bgandck@xxx; dtodd@wftxxx; Curtis, Gene; rjustman@xxx; Kerry Ridley; lindseylane@xxx; michael.todd@xxx; raqueen@xxx; sarastevenson@xxx

Subject:           dog days in the horse latitudes

Auto forwarded by a Rule

R/V Knorr
7/1/01

20:36

29'49"N

40'19"W

Routine has established itself.  The novelty of the daily actions is beginning to wane, and a nice pattern of the day has grown.  We awoke this morning to a placid slick sea, with hardly a breath of wind.   We are traveling through the "horse latitudes" which lie between the Mid-Atlantic high pressure system and the equatorial trade winds.  

This is a zone in the mid latitudes where the wind dies down and before the trades develop.  The early sailors, concerned for their water rationing when met with these light winds were known to toss the livestock overboard to preserve water.  Thus the name for the sacrificed horses.  I’ve learned that the Doldrums and horse latitudes are situated in different locations near the equator. Doldrums are placed at five degrees north and south of the equator. Meanwhile, horse latitudes are located at 30 degrees north and south latitude. ... The air existing in doldrums is moist, while horse latitudes' air is dry. 

Placid slick sea with hardly a breath of wind.
This CTD is 10' underwater.

One benefit of this flat sea is the transparency of the water.  We are in extremely clear water and the lack of ripples on the surface provides an unparalleled view into the briny deep.  This became especially useful today as we arrived "on station".  The locations where we perform our sampling routines are referred to as station 1, 2, etc.  We are typically parked in this location from  9am to 3pm performing our various dipping, net dragging and other sampling techniques. As the ship is stationary for a long time, larger fish sometimes congregate in its shadow.  The clarity of the water enhanced our view of the 10' shark that nestled under us today.  Talk of swimming has dropped off considerably.  The clarity is due to these warm stable waters that have little nutrient value to the ocean life forms. We can measure the level of plankton activity by calculating the chloroform content as we lower a meter.   We can measure a layer deep down near the colder water where the plankton percentage is much higher.  The deep, colder waters have the nutrients, but not the light needed for photosynthesis.  Meanwhile,  the shallow waters exposed to the light have had the nutrients eaten up long ago with the plankton and now all the nutrient value is stored in the biomass itself not dissolved in the water.  This line of productivity moves as we cross the ocean and is now at 120m -140m. The deepest some of these oceanographers have ever seen it.  It makes for a tremendously beautiful deep, deep blue when the sun is shining down and from behind one's view. 

I woke this morning to an accidental fire alarm. At 6am. I wasn't sure what kind of alarm it was so I was slipping upstairs to the lab to see if anyone was reacting when I was bowled over by someone charging up the stairs with their life vest, hat, and survival suit.  I returned to my cabin to collect my appropriate gear, with a little more haste than I had been showing.  Safety is taken very seriously and since this boat routinely supports visiting scientists for 1-4 week durations, they perform weekly fire drills and abandon ship drills.  

Everyone is provided with a life preservers, but more importantly, immersion suits, or survival suits.  These are similar to scuba diving "wet suits" but they are completely enclosed, suits, encompassing body, arms, legs, hands, feet, and head.  They keep one from developing hypothermia when exposed to the ocean waters.  The drill was awfully morose, and sobering, as we all practiced getting into these "gumby" suits. But if we ever had an emergency, we are all prepared. 

Tomorrow we are scheduled to arrive at our 1st major station where we are to recover the sediment sampling device which this group left last year.  Today we ran through the rigging routines, and practiced handling the gear and devices we will be deploying tomorrow.  A few of us sat around and practiced our traditional sailor skills by splicing eye holes into 

line holding our gear together. It’s an ancient art and our examples were representative of our experience level.  No seasoned whalers amongst our crowd.  We better stick to our computers. 

  

Feel free to respond to me, with less than a page, plain text, no attachments or pictures. 

KA, pls send on to Sklaven as his email is auto replying he is out of office  and i don't want junk email

From the Mid-Atlantic ridge,

David