Tag: weather data

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Sue White, May 26, 2008

NOAA Teacher at Sea
Terry Welch
Onboard NOAA Ship David Starr Jordan
May 27 – June 7, 2008

Mission: Juvenile Rockfish Assessment
Geographical Area: Central California Coast
Date: June 27, 2008

The wet lab's wind direction and wind speed instrumentation. Original to when the ship was built in the 1960's??
The wet lab’s wind direction and wind speed instrumentation. Original to when the ship was built in the 1960’s??

Science and Technology Log 

The DAVID STARR JORDAN (DSJ) departed from San Diego, CA this morning to begin Leg 3 of the Juvenile Rockfish Survey research cruise.  The seas have been rough and Leg 2 of this cruise was cut short because of the weather conditions.  Since weather has been such a huge influence in the last few weeks in this area of the Pacific and led to a loss of days at sea for the research scientists, here is some background for understanding the abbreviations and terms found in the “Weather Data from the Bridge” section above:

GMT = Greenwich Mean Time, international time which is the basis of time in each time zone around the world. Greenwich, England is located at Longitude 0° 0′ 0″, Latitude 51° 28′ 38″N (North of the Equator) or where the east meets the west.  The DSJ is on Pacific Time which is 7 hours earlier.

Latitude is the distance the DSJ is north of the equator, expressed in degrees (or hours), minutes, and seconds.

Longitude is the distance the DSJ is west of the prime meridian which runs through Greenwich, England, expressed in degrees (or hours), minutes, and seconds.

(Ship) Speed / Wind Speed refers to how fast the ship is moving or how fast the wind is blowing. Speeds on water or in the air are measured in knots (kts). One knot is one nautical mile per hour. A nautical mile (6076 feet) is a little longer than a mile here on land (5280 feet).  Use this conversion factor to change speed in the weather data to speeds on land:  1 knot = 1.16 mph.  Here is a fun visual that connects wind speed in knots to our more familiar miles per hour.  It also gives a more qualitative description of what different wind speeds are like.

(Ship’s) Course refers to the direction the ship is traveling to and is based on a 360o compass.

Wind Direction refers to the direction the wind is coming from.  It is also based on a 60o compass.

oC = degree Celsius

  • The conversion factor to change metric temperature to our more familiar Fahrenheit scale is: [(°C X 9) / 5] + 32 = °F 
  • An easy way to estimate, that you can do in your head, is to take °C and multiply it by 2 and then add 30 to get approximate °F: (°C X 2) + 30 = approx. °F 
  • Want to do it the other way?  Take your temperature at home, subtract 30 and divide by 2 to get the temperature in degree Celsius:  (°F – 30) / 2 = approx. °C 

Surface Water Salinity simply stated, describes how salty the ocean water is at the surface and can be referred to in PSUs (Practical Salinity Units).  It is based on the understanding that the electrical conductivity of seawater is related to its salinity.  A special conductivity meter is used at sea and the PSU value is calculated from the data.  PSU is not a unit of measurement, but a calculated value. The average world ocean salinity is around 35 PSU.

Relative Humidity is a measure of the amount of water in the air compared with the amount of water the air can hold at the temperature it happens to be when you measure it.  At the temperature given in the weather data above, the air has 71% of the moisture it can hold.  If the temperature decreases while the number of molecules of water is the same, then the relative humidity would increase.  The cooler air molecules are closer together and cannot hold as much water between them.

Barometric Pressure is the force the atmosphere is exerting on a given place, measured by an instrument called a barometer.  Think of it as being the “weight of air”.  Air pressure is recorded onboard using the unit mb, which stands for millibar.  A millibar is 1/1000th of a bar. A bar is a force equal to 100,000 Newtons pressing on a square meter.  You can feel the change in pressure in your ears when you are flying in an airplane.  High pressure usually means good weather and dropping pressure means the weather is changing. Low pressure often brings precipitation.

Vlad and Sam prepare to lift our link to land.
Vlad and Sam prepare to lift our link to land.

After being in port since Friday, the ship officers and crew are busy with a flurry of preparation to be at sea again. Bags of groceries were brought aboard this morning while a steady stream of people came aboard too.  The ship went from being asleep to bustling in a matter of hours.  Engines were started and soot flakes billowed.  Deck crew began the tasks of taking up the walkway and casting off. Ship officers were stationed on the port side (left hand side if you are facing towards the front of the ship) to report ship positions as we began to move away from the pier.  We headed out to sea, passing what looked like a series of empty boat slips. As we got closer I could see dolphins there and trainers were putting them through their paces.  The ship’s electronics technician, Kim Belveal (U.S.Navy, ret.), explained that this was a Navy training facility and the dolphins were trained to do very specific tasks, often tasks that reduced risk to people. We passed a Coast Guard ship truly under sail, rigged with huge sails. The lead fisherman, Jose’ Coito, has a son who is in the Coast Guard. He proudly told about his son’s training on that grand ship.

Personal Log 

It has been a whirlwind time in the last week for me.  I gave my last final exam for the school year on Friday morning, wrapped up the last details for school that afternoon, and headed home to pack. Since the last leg of the cruise was cut short, my travel plans changed within the last few days as well, meaning that I was going to be a NOAA Teacher at Sea one day earlier than planned and flying to a new destination as well. I flew to San Diego on Sunday and got to the ship Sunday evening. After settling into my stateroom, I felt a little like Goldilocks walking around the ship and making myself at home.  It was very quiet, but eventually I met the ship’s electronics technician and Sam Brandal, an able fisherman, who had also just arrived on the DAVID STARR JORDAN to fill in for someone on vacation.  It has been nice to have some down time to make the transition from school to my time as a Teacher at Sea.  I spent today on the fly bridge with my binoculars.  Chico Gomez, the chief bosun (also spelled boatswain), and Jose’ helped me spot whales on the horizon.  I also saw seals and dolphins closer in to the ship.  Sea jellies which ranged in size from about 2” to 10” floated by from time to time.  Work starts tomorrow when we pick up the scientists at Avila and do the first transect schedule for this leg of the cruise at Point Sal, CA . . .

Challenge Yourself 

Can you compile your own weather data from your home or school?  Use measuring instruments you already have, or research in your local newspaper or online.  Fill in the table below, converting your data to match the units and values from the DAVID STARR JORDAN bridge:

Screen shot 2013-04-20 at 5.04.07 AM

Here’s a quote from Rachel Carson that pretty much sums up what it’s like to look off the side of the ship: “We can only sense that in the deep and turbulent recesses of the sea are hidden mysteries far greater than any we have solved.” What mysteries will I see?

Sue

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Thomas Nassif, July 21, 2005

NOAA Teacher at Sea
Thomas Nassif
Onboard NOAA Ship Nancy Foster
July 15 – 24, 2005

Mission: Invasive Lionfish Survey
Geographical Area: Southeast U.S.
Date: July 21, 2005

Thomas Nassif on the Bridge gathering measurements from the ship’s weather log.
Thomas Nassif on the Bridge gathering measurements from the ship’s weather log.

Weather Data

Latitude: 33°30’N
Longitude: 77°09’W
Visibility: 10 nautical miles (nm)
Wind direction: 290°
Wind speed: 15 kts
Sea wave height: 3′
Swell wave height: 3-5′
Sea water temperature: 28.9°C (84°F)
Sea level pressure: 1019.9 mb
Cloud cover: overcast, cumulus and stratus

Science & Technology Log

The day began with rocky seas, gusty winds, strong ocean currents, and the tallest swells we’ve had since our departure from port last week.  These ocean conditions are nothing extraordinary for the ship’s crew, but extremely tough for the divers.  The diving site for this morning was Southeast Tower 2, not far from the old Frying Pan Tower that was used by the Coastguard to collect and transmit ocean conditions.  The Tower’s location 35 miles off the Atlantic coast atop a 45-foot deep rock formation made it among the most valuable navigational aids for collecting ocean data such as wave height and water temperature.

The 187-foot NANCY FOSTER in the Atlantic. The Bridge is located on the very top level of the ship.
The 187-foot NANCY FOSTER in the Atlantic. The Bridge is located on the very top level of the ship.

The first dive of the morning went smoothly.  But the second dive team was not so fortunate. After jumping off the ship they were swiftly pulled past the dive site buoy by strong ocean currents. Having missed the dive site, the divers ended up at an entirely different location on the ocean floor! This is why it is so important for ships to record the weather conditions and their location at sea.  These measurements take place on the Bridge, the command center of the ship.

Every day, I walk to the Bridge to get the weather data that appears at the top of my daily logs. Here is an explanation of the terms:  Latitude tells you how far north or south you are from the equator (which is 0° latitude), while Longitude tells you how far east or west you are from Greenwich, England (0° longitude).  Together, Latitude and Longitude give the exact location of the ship. Visibility is how far ahead you can see from the ship.  On a very foggy day you may only have a visibility of 10 feet, whereas on a clear day you can see all the way to the horizon, or 10 nautical miles.  Wind direction tells you which way the wind is blowing from – 0° is north, 90° is east, 180° is south, and 270° is west. Sea wave height and Swell wave height are height estimates of the smaller ripples and larger waves, respectively. Sea level pressure (or barometric pressure) indicates what the trend of the weather has been. High barometric pressures (like today – 1019mb) usually mean sunny weather; rain cannot build up in clouds if they are being squeezed together by high pressure. Low barometric pressures tell you that rain or stormy weather is on the way. Inside the eye of a hurricane barometric pressures can be as low as 875mb!  Under low pressures clouds can expand and fill up with rain.  Cloud cover is a number between 0 and 1 that describes how much of the sky is covered with clouds.  4/8 means that half of the sky is covered with clouds, 1/8 means very few clouds, 7/8 is mostly clouds, and overcast (or 8/8) is all clouds.

A lionfish has many fins. The outstretched pectoral fins are not venomous. The shorter, pointier spines are venomous. From right to left they are: dorsal, pelvic, and anal spines. Photo courtesy of Christine Addison.
A lionfish has many fins. The outstretched pectoral fins are not venomous. The shorter, pointier spines are venomous. From right to left they are: dorsal, pelvic, and anal spines. Photo courtesy of Christine Addison.

Every day the ship sends all of this weather information to the National Weather Service (NWS) by satellite.  The NWS will in turn fax this information to other ships that will be traveling in our area so they can get a better idea of what the weather is like at our location. And when our ship steams ahead to a new dive site tomorrow, we will be grateful if another ship was in the same area.  The weather information that ship collected will help us know more about the weather!

Question of the day

How many sets of venomous spines do lionfish have?  Where are they found on its body?

Lionfish (like most fish) have five different types of fins.  But in Lionfish, some fins have sharp, venomous spines. The dorsal (back), pelvic (waist), and anal fins all have pointy, venomous spines that look like injection needles. The caudal and pectoral fins, on the other hand, are not venomous and look more like ordinary fish fins.

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Mary Cook, January 2, 2005

NOAA Teacher at Sea
Mary Cook
Onboard NOAA Ship Ronald H. Brown
December 5, 2004 – January 7, 2005

Mission: Climate Prediction for the Americas
Geographical Area: Chilean Coast
Date: January 2, 2005

Location: Latitude 41°47.12’S, Longitude 73°33.42’W
Time: 0830

Weather Data from the Bridge
Air Pressure (millibars) 1012.81
Relative Humidity (percent) 93.61
Wind Direction (degrees) 354.55
Wind Speed (knots) 7.03
Air Temperature (Celsius) 14.46
Water Temperature (Celsius) 11.62
Sunrise 0624
Sunset 2132

Question of the Day

What is a fjord?

Quote of the Day

“Withhold not good from them to whom it is due, when it is in the power of thine hand to do it.” King Solomon

Science Log

It’s raining! I haven’t seen rain since last year. The sky is thick with dark, billowing clouds and gray mist. Occasionally a patch of bright blue breaks through. But it only takes a few minutes until it’s eclipsed by a rain cloud. The land on both sides of the channel is shrouded in the mist and looks mysteriously enchanting. Only a few people onboard have ever been this way before and everyone is excited. Even these salty sailors are energized. Seals are popping up and playing all around. It looks like they’re chasing each other. We’ve passed a couple of small fishing villages and there are some ferryboats in the channel. The Chilean pilot told me that we’re in a very interesting place because of the strong current. Our ship is traveling against a three knot current at this time and they’ve brought more engines online just in case we need them. He said the current can get as high as eight knots! I heard Captain Wright say that the last time he was through here the ship was going with the current and traveling at 21 knots!

Bruce, the boatswain is now on constant anchor alert. There are many potential hazards when traveling the narrow channels so all hands must be prepared for anything.

I’ve been standing outside in a sheltered place under the ladderways for about an hour. At first it didn’t seem cold but as time went by I felt the chilly dampness in my muscles and had to zip up my jacket and put on my hood.

Something I’ve learned about this ship is that even when the scientists aren’t actively conducting research projects, science is always going on aboard the RONALD H. BROWN. At the top of every hour they always record the weather data, which includes about 50 entries, and then send it in to the National Weather Service every six hours. If the ship is within 200 miles of the coast of the United States or Canada or within 300 miles of a named tropical storm or hurricane they report every three hours. They record the ship’s location and speed, plus wind factors, temperatures, pressure, clouds, precipitation, wave size and directions, swells, and presence of ice. It seems to me that everything is written in code. They have the “Ship’s Synoptic Code Ready Reference” lying nearby and make use of it when filling out the charts. This information is entered into the National Weather Service computers and used for weather forecasting.

Personal Log

There’s a festive atmosphere throughout the entire ship. Everyone’s smiling and walking with a little extra spring in their step. These seasoned sailors are like little kids on Christmas morning, their eyes sparkling with anticipation. They’re out on the deck with their binoculars looking over the pastoral scenes of green rolling hills dotted with colorful houses and farms and churches connected by winding dirt roads. One of them said, “Just give me ten acres with a little house and I could settle down and live right here.” Several nodded in agreement. Then they spotted the big snow-capped mountains in the distance! Their dreams of settling down seemed to evaporate into thin air as their attention had been captured by the majestic and forbidding.

Our course is taking us through the Gulf of Corcovado and we’re just now passing the volcanic mountain for which the gulf is named. The pointy, snow-capped mountain is Mt. Corcovado and it stands 2300 meters in elevation which is about 7000 feet high.

The water is so smooth in this gulf that I can barely tell the ship is moving. It’s great! Seasickness is but a distance memory.

Officer Ayers just told me that I missed a fabulous display of bioluminescence last night about 0200. I said that I’d just stay up all night tonight so I could see that for myself. Then watch-stander Melton says, “Oh, now you want to be awake and out at 0600 tomorrow because we’ll be entering an extremely narrow channel. You can’t be sleeping through that.”

Decisions. Decisions.

Whales on the starboard bow! I ran out and saw three waterspouts and one tail. Pretty cool.

Tomorrow, my students and co-workers will be returning to school from their Christmas break. I hope they’ve all had a good vacation and come back with renewed energy and smiles. I can’t help thinking about them and wishing they could be out here in this never-ending, ever-unfolding story of exploration.

Until tomorrow,

Mary

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Diane Stanitski: Days 20-25, September 4, 2002

NOAA Teacher at Sea

Diane Stanitski

Aboard NOAA Ship Ka’imimoana

August 16-30, 2002

Day 20: Friday, August 30

We arrived in Nuku Hiva with a bright sun beginning to set behind a band of gorgeous clouds. There was an air of excitement flowing through the group as land came into view. Because it’s customary to raise the flag of the country that you’re visiting, Steve, the ablebodied seaman and the XO, Doug, raised the French flag before arriving in port. We had a morning all hands (all on board) meeting to collect passports and explain procedures for docking. I spent most of the afternoon answering emails and working on lesson plans, two things I hadn’t had time to do this week because of the daily broadcasts that we completed. I also packed my books and clothes and began taking more pictures of all the spaces and people I hoped to remember on the ship. Aaaahhhh, I had such mixed feelings about leaving. We slowly made our way into the middle of Taihoae Bay, anchored, and raised a round black flag on the front mast designating that the ship is anchored. As we were waiting to hear from the gendarmerie, Nemo spotted three manta rays off the port side of the bow. They sailed through the water with kite-like bodies. Rain began to fall and we were finally told that we could take the RHIB to shore and that our passports would be stamped the next morning. A group of us decided to visit one of few local restaurants, a place that serves pizza, and we all enjoyed an evening together on land. Many people said that they still felt the rocking of the ship, even though we were on land, but I felt firmly planted. Don Shea and I felt so good that we decided to run back to the pier after dinner. Oh, what a feeling to run on solid ground!

Day 21: Saturday, August 31

I awoke early on the ship to depart on the 7:00 AM boat taxi to town. We wanted to make sure that we received the appropriate departure paperwork so we wouldn’t have a challenging time leaving French Polynesia in four days. With all paperwork complete a group of us walked along the one main road in the small fishing village to the bungalows at Pearl Lodge where John Kermond and I would stay. Wow, what a wonderful place! It overlooked the bay and had a beautiful (very small) pool with a pretty patio. I filled out the necessary paperwork for my room, but it wasn’t quite ready so I decided to return to the ship to gather my luggage. After a final goodbye to the KA (or so I thought), John and I returned to the Pearl Lodge, found our rooms, and were able to unpack and settle in for two nights. The Captain led a group hike over the mountain behind the lodge to beautiful Colette Bay where we swam in the waves and imagined that we were part of the Survivor series. We then scaled the volcanic cliffs to the end of the peninsula where a group of people were fishing for barracuda. Upon return to the hotel, I showered and decided to return to the KA one last time to check and reply to emails from my students. The ship was quiet because almost everyone was cherishing the last moments on shore before ship departure the next morning. I walked around the ship and a real feeling of sadness came over me. I was very surprised at my response to bidding farewell to this ship and the people I’d learned so much from during the last two weeks. I could really get used to life at sea. With a wave to the XO and Fred Bruns on the ship deck, I hopped back onto the boat taxi around 9:00 PM, was whisked away into the night air, and then returned to the bungalows for a much needed rest.

Day 22: Sunday, September 1

Nuku Hiva is predominantly Catholic and so the 8:00 AM Catholic service in town was the place to be on Sunday morning. The entire town was there. The church was absolutely beautiful and the music lifted the roof (as John said) off the building. The service was in both French and Tahitian, but very traditional and so easy to follow. Everyone, I mean EVERYONE sang the songs and that made it very powerful. After the Mass, we walked back to the bungalows to film the ship’s departure, however, it didn’t leave until nearly noon and so we waited for 2 hours on the hotel’s patio while the weather changed from hot and sunny to a torrential downpour with strong winds. After its departure we were then invited to take an afternoon jeep tour to the Typeevai, the valley where Herman Melville wrote his book Typee. We hiked to a ceremonial site with 11 Tikis carved in 1200 AD from the volcanic rock of the island – beautiful! It poured on us and our guide broke off a huge banana leaf that we used as an umbrella. I managed to receive about forty mosquito bites on my legs and arms and our guide picked a lime, cut it open, and applied it to the bites to relieve the itch – marvelous. What a gorgeous island.

Day 23: Monday, September 2

After a few hours making final arrangements for our flights and filming the last shots of Taihoae, we departed by four-wheel drive Land Rover later in the morning for a two-hour exciting trip to the airport northwest across the mountains and valleys of the remote, rugged island of Nuku Hiva. In the pouring rain the trip was treacherous. At times, the mud was up to the top of the tires and, although we had a difficult time seeing through the fog, we could tell there were steep cliffs on one side. Our driver had clearly made this trip before. We arrived safely and waited for our 3-hour flight to Papeete, Tahiti. We flew over atolls and through beautiful trade wind clouds.

Day 24: Tuesday, September 3

This was our only day in Tahiti. We awoke early and called Meteo France to see if we could have a tour of the weather station at the airport. We were trying to discover where the meteorological readings had been taken for the 100+ years of data recorded and now used to determine the Southern Oscillation Index. After a challenging conversation half in French, half in English, we were finally able to ask the necessary questions and receive a historical summary of the station. We were given a tour of the airport’s weather station and pamphlets to provide to my classes. John filmed the entire meeting. I was especially excited about this side trip because I’d always wanted to visit this specific weather station. Next on my list is Darwin, Australia, the sister site to the Tahiti station – maybe in a few years.

This experience has been like no other for me. I am so grateful to Dr. John Kermond, Jennifer Hammond, Rear Admiral Evelyn Fields, NOAA, NSF, Shippensburg University and all those responsible for my incredible journey. I will use the information that I learned on this trip in my classes, but more importantly, I hope to share the excitement and wonder of science with my students and my teaching colleagues so that they can understand the importance of conducting scientific research to discover more about our world and ourselves. Thank you to all!

Signing off for now, but I hope to hear from you again at dmstan@ship.edu.
Best wishes,
Diane