Science!

Some people have been asking what I do on the Palmer. (My parents forward me any comments left on the journal, in case you were wondering.) We collect magnetic, gravity, and multibeam data as we sail. Unfortunately, we're not doing seismics, which would have been a blast (literally...). We also do XBT launches. The XBT (Expendable Bathy Thermograph) looks sort of like a missile with a copper wire extending back to the ship. It collects temperature data as a function of depth.

The multibeam works like sonar. A "ping" is sent out from the ship, and instruments on the bottom of the ship record when it returns. Based on the temperature data from the XBT, the distance to the bottom of the ocean is calculated. The instruments record data from an array of angles, so for each ping we get a line of data. You can hear the ping from most parts of the ship, and the first time I noticed it I thought there was a bird sitting outside the window. You can hear it from the bedrooms... once every few seconds... all night long... Grr.

There are 6 watchstanders, and we each have 4 hour shifts, so that one of us is on duty at any time during the day. C.H. is midnight - 4 AM, R.G. is 4 AM - 8 AM, me 8 AM - noon, M.C. is noon - 4 PM, R.A. is 4 PM - 8 PM, and I.M. is 8 PM - midnight. So it ends up that R.A., I.M. and I hang out together during the day, and C.H. and R.G. hang out together at night just because of how the shifts worked out.

We have to make sure all the instruments are working correctly and recording data. Every 15 minutes we record everything in an Excel spreadsheet and in a written watch log. We also have to watch the multibeam and adjust the angles constantly. When the weather is good and we're getting good data, we set the multibeam at a larger angle, so that we collect the most data we can given the conditions. Just right now the data is lousy, and I keep having to decrease the angle.

When we're not on shift, we edit multibeam files. This mostly involves deleting bad data points. If the temperature data doesn't match the actual ocean temperature, we get smilee and frowny pings (it looks like the topography curves up or down at the edges, when that's not what's actually going on). When the ocean is rough, air mixes with the water, which completely messes up the multibeam, so even though the instruments account for the pitch and roll of the ship, the data's still bad.

That's about it. I'm going to watch V. and S. do a XBT launch this afternoon, so hopefully I can post some shots of them getting drenched on the back deck. (V. does her own XBT launches to collect data for the National Weather Service and for Scripps, and S. is the representative from Raytheon.)

(originally posted on Livejournal)