Day 1

Day 1

This blog is an attempt to describe the daily events and activities aboard the National Oceanic and Atmospheric Administration (NOAA) ship Ronald H. Brown, a class 1 research vessel. I have been conducting scientific field experiments for the past eight years and leading missions aboard the Brown since 2004. This is not the type of work that I conceived I would be doing when I graduated from college twenty-four years ago, nor what I thought I would be doing when I began my first university position, fifteen years ago. At those junctures, I saw myself in the laboratory developing, testing, and employing laser-based instrumentation for fundamental studies of molecular collisions and their dynamical implications. Times have surely changed.

Field experiments present unique challenges depending on whether you are on land, air, or at sea (and boy, do I have experience with their challenges in all media!). I am no longer involved in flight experiments but participate regularly in observational experiments on land at sea. My chief aim in all of these pursuits is to make observations that will enhance our understanding of space-based (satellite measurements), model predictions, and of basic chemical and physical processes that influence our environment on multiple scales. That sounds like a mouthful but the motivation is quite simple. There are particles in the air, unseen to the naked eye, which influence all aspects of our existence. These particles are commonly known as aerosols and can be either liquid or solid in nature. Aerosols control energy balance, the global water cycle, and human and ecosystem health across the globe. Aerosols are both physically and chemically dynamic, both reacting within the environment and transforming the environment as they change. These complexities are rarely represented accurately, if at all, in current weather, climate, or even air quality models. By understanding the nature and transformations of these ubiquitous particles, we can develop better predictive models that will assist in protecting lives (health, severe weather alerts), quality of life (climate change, air quality), and economy.

The things that we lean about aerosols in the earth’s atmosphere can also be used to explain atmospheres observed throughout our solar system and universe. Thus, these studies may serve as a launch pad for investigations of extraterrestrial atmospheres and the interstellar medium – anywhere that airborne particles exist! The current project is focused on aerosol processes in the tropical Atlantic Ocean.

Today is July 11, 2009, the first day of the 2009 Aerosols and Oceanographic Science Expeditions or AEROSE-links. This is the fifth cruise that we have conducted for the purposes of investigating the properties and impacts of Saharan dust transport in the tropical Atlantic Ocean. Beginning in 2004 and repeating annually since 2006, we have partnered with NOAA, NASA, and several universities to make measurements of atmospheric chemistry, radiation, meteorological and cloud properties, sea surface temperature, and fluxes. We have also collected environmental samples of aerosols for the purposes of examining the physical, chemical, and microbiological characteristics of the aerosols and how they change during long-range (trans-Atlantic) transport. The AEROSE team has partnered with NOAA AOML since 2006. In particular, we have partnered with oceanographers Drs. Rick Lumpkin and Claudia Schmid of the PIRATA-Northeast Extension (PNE) link and Argo-link Science missions, respectively. These missions are designed to investigate critical aspects of physical

During this year’s AEROSE cruise, we bring fewer experienced team members than ever since we first began. Only five of the twelve members of the AEROSE team have sailed aboard the Brown previously. This year’s cruise begins in Bridgetown, Barbados and ends (after a brief refueling in San Juan, Puerto Rico) and ends in Key West, Florida. We will be at sea for 31 days from July 11 until August 10, 2009. Our journey will begin with a nine day “deadhead” southwest to the equator and 23^oW. From there, we will move along the 23^oW longitudinal line to about 25^oN, passing by the Cape Verde Islands along the way.

This being the fifth cruise on this vessel, we are filled with both anticipation and anxiety. Last year’s cruise was wrought with problems stemming from engine and infrastructure issues with the vessel. In previous years, we have been fortunate enough to encounter significant dust storms (2004), biomass outflows (2006), and mixtures dust and smoke (2007). This year’s cruise is scheduled later than any of the previous cruises and the timing coincides with the early hurricane season. Though current projections do not place us in any danger, we do expect to see significant dust activity based on dust storm frequency and intensity observed earlier this summer. While in Barbados, a Saharan dust layer was apparent as haze on both the horizon and during solar zenith. Residents and personnel at the Caribbean Institute for Meteorology and Hydrology (CIMH) also informed me of a recent intense Saharan dust intrusion during the past week. Analysis of the dust forecasts for this week show an existing dust plume approaching us from the east above the inter-tropical convergence zone (ITCZ) and a smoke plume approaching us from below the ITCZ. The ITCZ is a region of converging air masses from the northern and southern hemispheres that leads to near constant convective activity, cloud cover, and intermittent rainfall. It also serves as an effective barrier to transport between hemispheres. The ITCZ migrates northwards of the equator in the summer and southwards (towards the equator) during the northern hemisphere winter. The AEROSE cruises have provided for serendipitous opportunities for in-situ examination of the cruise and chemical characteristics of the ITZC. The cruise tracks planned for this project simultaneously allow for the science missions of three independent but related projects (PIRATA, AEROSE, and Argo) to be achieved.

The close of the first day has been interesting. We held a scientific party briefing at 9am followed by a security briefing at 10am in the main laboratory. During this time the basic introductions are made, safety and security protocols are reviewed, points of contact identified, and points of concern expressed. Afterwards, a ship tour is provided for the first-timers. All of this went well and completed before lunchtime.

Shortly after departure, the ship experienced some choppy waters – partly because of our heading into the trades and partly because of the intensity of the crosswinds. The pitching and rolling of the ship wreaked havoc on the well-being of many of the students – especially those who had been up late the night before. I would estimate that the majority of the science team felt woozy or outright ill at some point over the first twelve hours. Sea sickness is an interesting phenomenon, especially in its mimicry of food poisoning. As bad as food poisoning can be, it is not uniquely combined with the incessant and unpredictable motions making balance a challenge, the inability to escape to a significant change in environment, the plethora of unnatural smells emanating from the ship, and the ever-closing walls of any room on the ship that you might occupy. I know that many of the students probably spent some time today cursing their existence, my existence, or the choice to participate on this cruise. I am confident that their sentiments will change in time. I just hope that the time comes quickly but one never knows.

Since there were so few students in the lab (actually there was only one), I set up my computers, developed the work plan, and typed up some basic instructions on the next few days’ worth of tasks. I stopped to eat a delicious lunch around noon (subs, chicken wings, and salad) and returned to work. The rest of my afternoon was spent unpacking and organizing the container that will house most of our instruments and organizing the workspace in the main laboratory. At night, I checked my emails and watched a couple of movies in the lounge. The lounge is just a small “family” room in which a large screen monitor is located for movies to be shown. This represents one of the three primary sources of recreational activity aboard the ship – exercise, reading, and watching videos – if one discounts eating! I’ll provide photos of each at a later time. Occasionally, we set up a ping pong table for some more competitive recreation. The first day is far too early for that type of diversion.