Friday, October 14, 2011

A visit to AMF2 site

We are modelers in a field program. It is one of our goals to understand how the observation data we use is made. I'd like to share what I experienced in my visiting to the second ARM mobile facility (AMF2) site. AMF2 is a part of AMIE (ARM MJO investigation experiment) project, which is a brother field campaign with DYNAMO. Dr. Charles Long from Pacific Northwest National Laboratory kindly introduced all the instruments in AMF2 to DYNAMO scientists including me.
An overview of the AMF2 site.
Dr. Charles Long (right) is giving an introduction to instruments to DYNAMO scientists.
An observation tower that measures wind, radiative fluxes, rain, and others.
This total sky imager takes a picture of whole sky in every few seconds. So later on we know how much cloud was there on a certain day.
This microwave radiometer measures the amount of three phases of water, those are vapor, liquid, and ice, in the atmosphere.
I found there were two ways to measure surface shortwave radiation from Sun.
This machine measures direct and diffuse shortwave radiative fluxes in a modern(?) way.
This small crystal ball measures the strength of sunshine too, how is it possible?
The crystal ball concentrates sunlight into one point beneath it and it burns the paper under the ball. The paper is burned severely in a day of strong sunshine. Note that this instrument belongs to Maldivian Meteorological Service and is not a part of AMF2.
Guess what? This measures rain rate! In the inner hole, there are two cameras that take picture with very short time interval. When it rains, fingerprints of rain drops are in those pictures, and from that we know how dense the rain drops are as well as a size distribution of the drops.
After all introductions, it was a time to launch a radiosonde. In AMF2, people launch the radiosonde 8 times a day, so in every 3 hours. Luckily, I got a chance to do that and waiting for a sign to launch a radiosonde. The helmet is just for biking and not necessary for a person who launches a sonde.
The radiosonde is consist of a balloon and this part. It contains several instruments that measures atmospheric temperature, humidity, pressure. It also has a GPS receiver so that we could track the location of the sonde.

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