Temperature Observing Tips

The study of the two different types of temperature sensor housings for official co-op and National Weather Service temperature readings has always been a penchant of mine. Accuracy is of the utmost importance as scientists strive for good, quality, reliable and accurate data on a timely basis. The question, which has always intrigued me, is what good is studying temperature data if it is not gathered in a consistent manner? How can one come up with a legitimate logical hypothesis with "bad" data? What if we are not comparing the proverbial "apples to apples"? Does or can the design of a temperature shelter or shield effect the readings? I will try to briefly explain my personal thoughts and opinions on this matter. First, I must tellyou that I am an official co-op observer for the National Weather Service and take daily readings of temperature and precipitation of both rain and snow. The snow is always melted down to get the liquid equivalent during the winter. Station identification is: Sussex 8 NNW 28-8648. The 8 NNW after the name Sussex means that my location where the readings are taken is 8 miles north-northwest as the crow flies from our Post Office. I also happen to be the furthest northwestern official station in New Jersey living in extreme northwestern Sussex County. Recently, I was asked by the National Weather Service to take the official readings at High Point State Park as well. The station established by myself there is a two mile drive yet higher in elevation by 500 feet. Although not at the highest point, which reaches 1,803 feet, there is many times a big disparity in snowfall amounts just between my location. This of course is due to elevation. Let's first look at the Cotton Region Shelter (CRS). Although these wooden louvered boxes are airy, roomy and easily accessible there are several problems that I have experienced over the years. First, the fact that they are made of wood means that they MUST be constantly well cleaned and most of all painted. I paint mine on an average of twice per year. This is messy and costly as the observer doesnxt get reimbursed for purchasing much needed paint. The second very important aspect of these shelters is since they are made of wood, the wood does deteriorate no matter how many coats of paint you apply. My oldest shelter came apart at the seams as the internal wood became soft and was unable to maintain the hardware holding the shelter together. The CRS is also obtrusive to many people because of its size. It obviously was designed that way to allow room to mount the horizontal liquid in glass (LIG) thermometers. There is also room for a thermograph. One thing I discovered with this shelter is if you are using the liquid-in-glass thermometers inside, because of the little bit of giving on the front door when it is windy the vibration from the front door moving back and forth causes the index in the minimum LIG to slide downwards. I actually found this out by "mistake" when I was taking a reading during a windy day. If your front door has any play in it when the door is closed you probably have had some artificially induced false lower minimum temperatures. You can test this yourself if you have the CRS and a horizontally mounted minimum LIG thermometer by setting the index to the current temperature on the thermometer, closing the front door as normal and then push and pull on the front door handle gently. Then check if the index slid to a lower reading then the present temperature or set point. If your front door happens to have no play in it, you're okay. One other negative is the attraction of birds,wasps and other unknowns from the insect world to the shelter, especially building nests. They must be moved as soon as possible. Last, but not least is an important heating that takes place when snow is on the
ground when the winds are calm and it is sunny. The reflection of solar radiation from the snow to inside the instrument shelter because of the large slot openings on the bottom of the shelter causes an increase in temperature when the solar angle is right. The M.M.T.S. Multi plated shield does have some good qualities. First, since it is made of plastic it does not require any painting. When the housing gets dirty you simply wipe the unit off as needed with a damp cloth with a very mild soap. Because it only houses a temperature probe it does not have to be large. One negative is this; it is the removing of the temperature sensor for any reason. It takes time and you must be careful with the wiring. Solar radiation from the reflected snow cover during sunny days is nil because of the design of the system. Remember, it does only hold a temperature sensing probe. There is room for nothing else. Well, almost. On occasion I opened a couple of shields and seen small spiders and insects mount themselves on the silver probe with some even making webs on them.This is not as easy to clean and impossible to see without removing the layers of shield and opening it up. The probe cannot be seen from outside without removing the shields. Because of its size, it is easy to remove and is less obtrusive then the CRS. I personally like them over the CRS. For long term studies though, we must compare apples to apples. If one has been taking daily readings of temperatures using the same CRS and the same accurate LIG in the same location for years, why change? That is a perfect location to study climatology. That way there is minimal margin of error and no questions about the archived data. We are only comparing types of shelters here, not instruments or instrumentation accuracy. That will come at a later date. My personal conclusion is as technology changes and we get more sophisticated ways of measuring our atmosphere with more accuracy, things will always
continue to change. Who has the absolute correct answer? GOD is the only one. Not me! My goal is to maintain daily accurate readings of temperature and precipitation at the same location using the same equipment with the same type of instrument shelter whether it be the MMTS or the CRS for the rest of my reliable weather observing days. This way 100 years from now some student, forecaster, teacher, or climatologist can say that these are records we can rely on.

Nick Stefano Sussex 8NNW 28-8648 New Jersey U.S.A.