Nancy Lewis
Onboard NOAA Ship Ka’imimoana
September 15 – 27, 2003
Mission: Tropical Atmosphere Ocean (TAO)/TRITON
Geographical Area: Western Pacific
Date: September 24, 2003
Sunrise: 0613
Sunset: 1828
0600: All wogs on bow
Transit to Honolulu
Time Change: Set your clocks back one hour to Hawaii time
Weather Observation Log: 0100
Latitude: 9 degrees, 57.8; N
Longitude: 141 degrees, 41.6’ W
Visibility: 12 nautical miles (nm)
Wind direction: 130 degrees
Wind speed: 7 knots
Sea wave height: 2-3 feet
Swell wave height: 4-6 feet
Sea water temperature: 27.8 degrees C
Sea level pressure: 1012.2 mb
Dry bulb pressure: 27.0 degrees C
Wet bulb pressure: 26.0 degrees C
Cloud cover: 7/8 Altocumulus, cumulus, altostrattus
Air temperature: 27.0 degrees C
Science and Technology Log
The phenomenon known as El Nino will be the subject of our discussion today. El Nino is a recurrent weather phenomenon that has been known for years by fisherman along the coasts of South America. During an El Nino, the normally strong easterly tradewinds weaken, bringing warmer than normal currents eastward to the the coasts of Peru and Ecuador. Fishing drops off, and there can be catastrophic effects in weather all the way from Australia and Indonesia to both American continents.
During the unpredicted El Nino of 1982-83, the effects began to be felt in May. West of the dateline, strong westerly winds set in. Sea levels in the mid-Pacific rose several inches, and by October, sea level rises of up to one foot had spread 6000 miles east to Ecuador. As the sea levels rose in the east, it simultaneously dropped in the western Pacific, destroying many fragile coral reefs. Sea temperatures in the Galapagos Islands rose from the low 70 degrees Fahrenheit to well into the 80s. Torrential rains on the coast of Peru changed a dry coastal desert into a grassland. Areas from Ecuador, Chile and Peru suffered from flooding as well as fishing losses, and that winter there were heavy storms pounding the California coast, the rains that normally fall in Indonesia. The effects of this El Nino to the world economy were estimated to be over $8 billion.
During the 1920s, a British scientist, Sir Gilbert Walker, pioneered work in what he called the Southern Oscillation Index. Using data from barometric readings taken on the eastern and the western sides of the Pacific Ocean, Gilbert discovered that when the pressure rises in the east, it falls to the west, and vice-versa. When the pressure is in its high-index, pressure is high on the eastern side. The pressure contrast along the equator is what drives surface winds from east to west. When the pressure is in the low index, the opposite condition occurs. Easterly winds usually disappear completely west of the dateline, and weaken east of that point.
The TAO/Triton array is part of an international effort to be understand, in order to be able to predict and prepare for such events as El Nino and its counterpart, La Nina. Formerly, data was collected from historical records, instruments at tide gauging stations, and also the observations made by ships transiting the ocean. The data that is being collected will be able to help scientists hone their understanding of the complex relationship between the atmosphere and the oceans. We have only recently become aware of the profound effects that climate changes in far flung points on the globe have for many parts of the inhabited world. It is a sobering fact to realize that oceans cover 71% of our planet, and that, next to the sun, the oceans are the biggest determinant of climate and weather.
Personal Log
The buoy operations are over and we are now steaming our way back to the KA’s home port of Honolulu. The ship is basically moving at approximately 10 miles an hour, so in 10 hours, we only travel 100 miles. Our estimated time back is sometime Sunday evening.
Fishing lines have been set out off the fantail, and the crew is beginning to clean up the gear, power washing the deck and acid cleaning the sides for our grand entry back in Hawaii. Tonight in the mess lounge, we had the “wog Olympics” where we competed in such races as rolling olives on the floor with our noses.
My usual routine has calmed down a bit, but we are still making videos. Some of them have to be tossed and redone if I flub my lines too much. It was raining today, the sky a mass of almost evil-looking clouds.
We also had periods of rain and drizzle. I paid a visit to the bridge asking for any old navigation charts, and came away with a bundle.
I am also busy rehearsing my “act” for tomorrow night’s performance on the fantail after a barbecue dinner. We wogs are expected to provide the evening entertainment for the honorable shellbacks.
Tonight for the first time, I watched some television. We have programming provided by the Armed Forces Network. I’d like to take this opportunity to send my best wishes for a safe return to all those men and women serving in the current conflict in the Middle East, and most especially to PFC Noel Lewis and all those in his unit.
Question of the Day: What is the difference between weather and climate?
Aloha from the KA!
Nancy Lewis