Days 7 and 8 AEROSE-V

I am starting to have fun out here now. Over the last couple of days, we have begun to collect a data stream, “sniffing” the sky through passive and active measurements for the first evidences of distant fires and dust storms traversing the oceans. The passive measurements include the radiometers, spectrometers, atmospheric profilers, and gas sensors. The active measurements include the samplers and soundings. We are beginning to see some traces of new types of aerosols than we have been encountering but cannot be certain that they are not coming from ship activities (trash incineration and routine deck operations) or from the environment. The satellite images show a mixture of dust and smoke in our vicinity. The models predict that there is dust aloft and smoke near the surface. Here in the middle of the ocean, nothing but a light haze is visible to the naked eye and even that has been clearing over the past few days. We have not picked up any significant discoloration on our filters and the ozone and carbon monoxide levels have been fairly low and constant. The main indicator that we may actually be intersecting something is the laser particle counter and condensation nuclei sensors. Their counts have doubled or tripled over the last twenty-four hours… but we don’t really know why.

The main quandary is whether we are seeing dust, smoke, a combination of both, or neither in the aerosol instruments. We actually have too little data (and time) to figure this out but the discussions and opportunity to compare instrument responses over the last three days has been interesting. Apparently, the atmospheric motions have sandwiched three distinctive layers of aerosols: an aged smoke plume originating from fires in Angola and the Congo, urban air from coastal megacities in west Africa being circulated around the Gulf of Guinea, and dust from Saharan storms to the north of the ITCZ . (Sometimes, atmospheric sciences field research is like a geography crash course!) My feeling, based on experience and some eyeballing of the filters (they are grayish to black), is that we have little or no dust at the surface but some aged biomass aerosol and urban outflow. The measurements of our handheld sunphotometers tend to support this interpretation, as do and the aerosol size distributions and gaseous pollutant concentrations. The main thing missing is confirmation of the chemical composition of the aerosols that we are collecting. We will see as we progress towards the east. The signals that we are tracking should all increase if I am correct.

We have entered the EEZ (exclusive economic zone) of Brazil near the Saint Peter and Saint Paul archipelago just north of the equator. This is just a lonely a patch of rocks with a lighthouse situated in the middle of the Atlantic Ocean. However, because of international politics, we are restricted to a certain suite of activities while within 200 miles of its coastline. This means no balloons or oceanographic operations for nearly two days as we enter and exit its territorial waters. This will allow some boredom to creep into the psyches of the folks whose instruments are “detained” but there are plenty of other demands on our time.

I have been spending less and less time sleeping in anticipation of a “big” event. We have been hosting “midnight matinees” starting at about 11:30pm each night. These are planned down-times where we break from the monotony of our computers to go and watch a blockbuster, eat popcorn, and offer critiques over the soundtrack of some bombastic movie – usually action or comedy. Already, we have watched Body of Lies, Hancock, Gran Torino, The Changeling, Gladiator, Quantum of Solace, and Jumper over the last few days. This is good for me, since I do not watch much TV or go to mainstream movies. It also rejuvenates me for the home stretch of 2-3 hours additional work after the movie. Yes, that means I’m hitting the rack between 4:00am and 5:00 am each morning. I have grown accustomed to this but I can see the students who are attempting to keep up failing due to lack of stamina. The key is to take your power naps during the daytime, fuel up constantly (snack), and get your exercise. Once we get to 23^oW, the ship will be buzzing with activity on both ends. Moorings will be recovered, repaired and deployed. Multiple types of ocean and hydrographic profilers will be launched around the clock. Weather balloons and special sensors for ozone (called ozonesondes) will be launched at a minimum rate of four times daily. Radiometric measurements with the hand-held sunphotometer will be taken every thirty minutes. In addition, my group records data continuously from twelve different instruments. These data have to be quality-controlled, screened for contamination, recorded, instrument diagnostics checked, and cleaned almost on a daily basis.

We will arrive at 23^oW tomorrow. I anticipate visible smoke on the horizon (call me an optimist!) and a busy day for all of the science team. I have a growing concern that the students in my group are getting fatigued. This happens to everyone, but during the first week in a four and one-half week cruise is not a good sign. Two of the students are still seasick. One is almost constantly bed-ridden and the other is often incapacitated, even while in the lab. Two other students are experiencing recurring bouts of seasickness but are working through it. A fifth student is suffering from MADness. I am trying to talk him through but it is not yet sinking in. Wow! That is five of our eight students suffering. In fact, we may soon have to make an assignment change to account for the labor shortage on the ozonesonde preparation. Each day is a new challenge.