Reports from Jasmine
5/11/99 : 5/19/99 : 5/20/99
Sample Data
05/11/99
Got the predictions for 5/19. We are halfway into it and the sun has not
been out yet. We have a special satellite receiver on board that allows us to
pull down the full digital data from NOAA satellites as the pass over us. There
are three NOAA polar orbiting weather satellites and they go over us twice a
day. Based on their pictures, I would say we will be in a rainy region for the
next few days. It may be that the first major monsoon outbreak in the Bay of
Bengal is going to happen now.
I have attached graphs of the rainrate (mm.hr) from yesterday. The
horizontal axis is julian day (Jan. 1 is 1, Jan. 2 is 2, etc). I also attached
a graph of ocean surface temperature and air temperature. Question for the
class: Why does the air get cooler when it rains? Also attached a picture
(taken by Jeff Hare) of myself trying to look intelligent whilst sitting at a
computer in the main lab of the ship. He was testing our digital camera;
otherwise he might have selected a more interesting subject.
Here are some answers.
Are experiments fun?
There are enjoyable parts to most scientific cruises, but on balance they
tend to be monotonous and a long time to be away from your family. Also, I miss
things like being able to go to the Y and play basketball or enjoy a Sunday
morning eating croissants in the garden while listening to music. The time
difference is more difficult to deal with when you travel by air (which is how
we got here). This time, it didn't bother me at all even though it was 12
hours.
How do you know when a monsoon is developing?
The signals of an approaching monsoon are very tricky. We have a genuine
expert on board (Dr. Peter Webster from CU), and he has been puzzled at times.
The main things you look for are a certain wind structure: weakening of strong
westerly winds over the Himalyan plateau, build up of low level westerlies along
and north of the equator, and a buildup of high temperatures in the Bay of
Bengal. The monsoon rains are usually triggered by a large blob of convective
activity moving eastward along the equator. After that moves into Indonesia,
there is a tendency for convection to breakout over India (provided it is
monsoon time of year).
How fast can the Ron Brown move?
This ship can go about 14 kts with all generators on. It is a
diesel-electric powered ship, similar to approach used in diesel electric
trains. A diesel engine runs a generator that makes electricity, then the
electricity is fed to an electric motor that runs the ship's propellors.
What do you do during the day?
I get up at 7, eat breakfast, and start work about 8. I have a long list of
routine chores to do (check instruments, copy the previous days data files from
the acquisiton computer to two other processing computers, run a bunch of
processing programs, check on data quality to spot any failed sensors, etc). I
take a break for lunch and dinner. I usually work out from 330 to about 415.
After dinner I may work a few more hours, watch a movie, or read.
What is a CTD?
CTD stands for Conductivity, Temperature, Depth. I sent back a
picture
showing an example. There are three sensors on the CTD: an electrical
conductivity sensor, a thermometer, and a pressure sensor (that gives depth).
Electrical conductivity is converted to salinity (i.e., the amount of salt in
the seawater). The density of seawater is a function of temperature and
salinity, so precise measurements allow oceanographers to infer vertical
stabililty and large scale current structures.
Why is the ship called the Ronald H. Brown?
The ship is named after a former Secretary of Commerce who was killed in a
plane crash on a diplomatic mission to Bosnia serveral years ago. NOAA is in the
Dept. of Commerce.
What do you do if there is a hurricane?
If a hurricane approaches we will attempt to avoid it. This ship is not
appropriate for battling a hurricane. There is a hurricane in the Arabia Sea
right now (opposite side of India from us).
| 
