 and say hello to the cool oooo this is going to cause some stir http www URL essl msu background html received via URL using satellites to monitor global climate change earth system science laboratory the university of alabama in huntsville for additional information dr john christy associate professor of atmospheric science earth system science laboratory the university of alabama in huntsville phone NUMBER NUMBER NUMBER e mail christy URL dr roy spencer space scientist global hydrology climate center nasa marshall space flight center phone NUMBER NUMBER NUMBER e mail roy spencer URL summary as part of an ongoing nasa uah joint project dr john christy of uah and dr roy spencer of nasa s marshall space flight center use data gathered by microwave sounding units msus on national oceanic and atmospheric administration tiros n satellites to get accurate direct measurements of atmospheric temperatures for almost all regions of the earth including remote deserts rain forests and oceans for which reliable temperature data are not otherwise available the accuracy and reliability of temperature data gathered by the satellites since january NUMBER has been confirmed by comparing the satellite data to independent temperature data a recent study NUMBER found a NUMBER percent agreement between the msu data and temperatures measured by thermometers suspended beneath weather balloons released by meteorologists for weather observations once the monthly temperature data is collected from the satellites and processed it is placed in a public computer file for immediate access by atmospheric scientists in the u s and abroad it has become the basis for a number of major studies in global climate change and is cited in reports from the intergovernmental panel on climate change gathering the data while traditional thermometers measure the temperature at a specific point in the air a microwave sounding unit on a satellite takes readings that are average temperatures in a huge volume of the atmosphere each of the more than NUMBER NUMBER readings per day per satellite is an average temperature for more than NUMBER NUMBER cubic kilometers of air the msu makes a direct measurement of the temperature by looking at microwaves emitted by oxygen molecules in the atmosphere the intensity of the microwave emissions their brightness varies according to temperature christy and spencer developed a method to take the data from several satellites and produce a unified temperature dataset verifying the accuracy of msu measurements a recent comparison NUMBER of temperature readings from two major climate monitoring systems microwave sounding units on satellites and thermometers suspended below helium balloons found a remarkable level of agreement between the two to verify the accuracy of temperature data collected by microwave sounding units christy compared temperature readings recorded by radiosonde thermometers to temperatures reported by the satellites as they orbited over the balloon launch sites he found a NUMBER percent correlation over the NUMBER year period of the study the overall composite temperature trends at those sites agreed to within NUMBER NUMBER degrees celsius about NUMBER NUMBER fahrenheit per decade the same results were found when considering only stations in the polar or arctic regions the idea was to determine the reliability of the satellite data by comparing it to an established independent measurement christy said if satellite data are reliable when the satellites are over the radiosonde sites that means you should be able to trust them everywhere else the NUMBER radiosondes reported an aggregate warming trend of NUMBER NUMBER degrees celsius about NUMBER NUMBER fahrenheit per decade since NUMBER over those NUMBER spots on the globe the satellites also recorded a warming trend NUMBER NUMBER degrees celsius about NUMBER NUMBER fahrenheit per decade globally however the satellite data show a cooling trend of NUMBER NUMBER degrees celsius per decade since the first noaa tiros n satellites went into service these NUMBER radiosonde launch sites are just not distributed evenly around the planet christy said they are not representative of the total globe radiosonde balloons are released from stations around the world usually at noon and midnight greenwich standard time as each balloon climbs from the surface to the stratosphere the temperature is measured and relayed to the ground by radio while there are more than NUMBER NUMBER radiosonde launch sites globally the data from many sites either are not readily available or are not consistently collected christy used data from NUMBER sites at which there has been long term systematic and reliable data collection these NUMBER radiosonde launch sites are in a box bounded by iceland trinidad truk island and alaska in an earlier study an upper air temperature record compiled by noaa from NUMBER daily weather balloon sites around the world indicated a NUMBER year climate trend of NUMBER NUMBER c per decade which was in exact agreement with the satellite data at that time christy said global coverage one advantage of the msu dataset is its global coverage microwave sounding units aboard noaa satellites directly measure the temperature of the atmosphere over more than NUMBER percent of the globe each satellite measures the temperature above most points on earth every NUMBER hours the global temperature that has been frequently reported from surface measurements is neither global in extent nor systematic in measurement method it neglects vast oceanic and continental regions including antarctica the brazilian rain forests the sahara desert and greenland the most commonly cited historical temperature dataset is from ground based thermometers more than NUMBER NUMBER thermometers worldwide provide almost instantaneous local temperature data through links to weather services and scientists most of these thermometers which are usually in small shelters about five feet above the ground are in areas easily accessible to people in the u s and other industrial countries these thermometers are most often found at airports the ground based network is extensive in north america europe russia china and japan it is less comprehensive in africa south america australia and across much of southern asia temperatures on the surface and vertically through the atmosphere are gathered daily by thermometers carried aloft by helium balloons radiosonde balloons are released from stations around the world usually at noon and midnight greenwich standard time while balloon release sites are scattered throughout the world they are concentrated in industrial nations there are more than NUMBER NUMBER radiosonde launch sites globally if they were evenly distributed around the world that would equal approximately one for every NUMBER NUMBER square miles of the earth s surface water temperatures which are used to derive estimates of atmospheric temperatures come from thermometers on piers and buoys and aboard ships of opportunity the ships record the temperature of water drawn in to cool their engines the water temperature data from these instruments is also not global in its coverage tending instead to be concentrated in heavily travelled shipping lanes and in harbors in the past NUMBER years a new system of approximately NUMBER deep ocean buoys has been established gathering both atmospheric and water temperature data instrument accuracy msu with nine satellites measuring the temperature over periods of from one to six years a method was devised to merge all the data into a single consistent time series each satellite has its own bias that if not calculated and removed would introduce spurious trends the biases are calculated by directly comparing each satellite with others in operation at that time periods of overlapping operation ranged from three months to three years and were sufficient to determine these biases because the msu instruments are so stable and have so many thousands of observations the biases between the satellites are known to within NUMBER NUMBER deg the final product removes these biases so that all data are referenced to a common base NUMBER to check the final product comparisons were made over a NUMBER year period with balloon measurements as stated above and the phenomenal agreement provided the independent validation necessary to conclude that the merging technique developed for this dataset was accurate instrument accuracy ground based thermometers of great concern to scientists is the lack of consistency in the way readings are taken and in the thermometer surroundings since most thermometers for which long term records exist are in towns and cities the effects of population growth and the construction of nearby roads parking lots runways and buildings may cause the temperature to rise a little due of urbanization this temperature change may be an artifact of a local asphalt effect rather than a long term widespread climate change instrument accuracy ships of opportunity while the temperature data collected by ships at sea is reported as a sea surface temperature this data reflects water temperatures from about three to NUMBER feet below the surface the level from which water is drawn into the ships the thousands of individual thermometers used to collect this data are not calibrated against a scientific standard nor is there a method for verifying the accuracy of either the thermometers or the reports matching temperature readings to specific times and places only in places where there are many overlapping observations can there be any confidence in their accuracy the scientists in NUMBER spencer and christy received the american meteorological society s special award they were honored for developing a global precise record of the earth s temperature from operational polar orbiting satellites fundamentally advancing our ability to monitor climate ams special awards are given to individuals or organizations not appropriately recognized by more specifically defined awards and who have made important contributions to the science or practice of meteorology or to the society in NUMBER spencer and christy received nasa s exceptional scientific achievement medal dr john christy christy began his scientific career as a senior research associate at uah in NUMBER after earning his b a NUMBER in mathematics from california state university fresno his m div NUMBER from golden gate baptist theological seminary and his m s NUMBER and ph d NUMBER degrees in atmospheric sciences from the university of illinois he was an instructor of mathematics at parkland college in champaign il NUMBER NUMBER an instructor of mathematics at the university of south dakota NUMBER NUMBER and an instructor of mathematical sciences at yankton s d college NUMBER NUMBER he also served as pastor of the grace baptist church in vermillion s d NUMBER NUMBER and as science master at baptist high school nyeri kenya NUMBER NUMBER he has published more than NUMBER refereed scientific papers christy serves on the noaa national scientific review panel for the national climatic data center and on noaa s pathfinder review panel he was an invited key contributor to the NUMBER intergovernmental panel on climate change s scientific assessment of climate change and served as a contributor to the NUMBER and NUMBER ipcc reports dr roy spencer spencer began his career as a research associate at the space science and engineering center in madison wi in NUMBER after earning his b s NUMBER in meteorology at the university of michigan and his m s NUMBER and ph d NUMBER degrees in meteorology from the university of wisconsin madison he was a universities space research association visiting scientist at msfc NUMBER NUMBER before joining the msfc staff in NUMBER he is the u s team leader for the multichannel microwave imaging radiometer team and has served on numerous committees relating to remote sensing he directs a program involving satellite and aircraft passive microwave data to build global climate data sets and to address climate research issues spencer is lead author on sixteen scientific papers bibliography NUMBER j r christy NUMBER climatic change vol NUMBER pp NUMBER NUMBER NUMBER j r christy r w spencer and r t mcnider NUMBER journal of climate vol NUMBER pp NUMBER NUMBER r w spencer j r christy and n c grody NUMBER journal of climate vol NUMBER pp NUMBER NUMBER r w spencer and j r christy NUMBER journal of climate vol NUMBER pp NUMBER see also URL URL URL URL gary lawrence murphy garym URL teledynamics communications blog URL biz URL computers are useless they can only give you answers picasso 