Archives par mot-clé : Satellite Data

Which is the Most Accurate Satellite-Derived Temperature Dataset?

by Christy J.R. et al., April  6, 2018, in CO2Science


Monitoring temperature and creating regional and global temperature data sets is a tricky business. There are many factors that can induce spurious trends in the data; and there are multiple protocols to follow to ensure their proper construction. Consequently, many people (including scientists) have found themselves wondering which of all the temperature data sets is the most accurate for use in determining the impact of rising greenhouses gases on atmospheric temperature? Thanks to the recently published work of Christy et al. (2018), we now have a pretty good idea as to the answer.

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UAH finds a warming error in satellite data, lowers “tropical hotspot” temperature trend, contradicts IPCC models

by Anthony Watts, April 6, 2018 in WUWT


Weather Satellite Wanders Through Time, Space, Causing Stray Warming to Contaminate Data

In the late 1990s, the NOAA-14 weather satellite went wandering through time and space, apparently changing the record of Earth’s climate as it went.

Designed for an orbit synchronized with the sun, NOAA-14’s orbit from pole to pole was supposed to cross the equator at 1:30 p.m. on the sunlit side of the globe and at 1:30 a.m. on the dark side, 14 times each day. One of the instruments it carried was a microwave sounding unit (MSU), which looked down at the world and collected data on temperatures in Earth’s atmosphere and how those temperatures changed through time.

Mystery solved : Rain means satellite and surface temps are different. Climate models didn’t predict this…

by JoNova, March 18, 2018


A funny thing happens when you line up satellite and surface temperatures over Australia. A lot of the time they are very close, but some years the surface records from the Australian Bureau of Meteorology (BOM) are cooler by a full half a degree than the UAH satellite readings. Before anyone yells “adjustments”, this appears to be a real difference of instruments, but solving this mystery turns up a rather major flaw in climate models (…)

Where The Warmth Is

by Willis Eschenbach, March 24, 2018 in WUWT


I got to thinking about the “hiatus” in warming in the 21st Century, and I realized that the CERES satellite dataset covers the period since the year 2000. So I’ve graphed up a few views of the temperature changes over the period of the CERES record, which at present is May 2000 to February 2017. No great insights, just a good overview and some interesting findings.

UAH: 2017 was third warmest year in satellite record

by Antony Watts, January 3, 2017 in WUWT


From the University of Alabama, Huntsville.

Global Temperature Report: December 2017
Global climate trend since Nov. 16, 1978: +0.13 C per decade
December temperatures (preliminary)

Global composite temp.: +0.41 C (about 0.74 degrees Fahrenheit) above 30-year average for December.
Northern Hemisphere: +0.50 C (about 0.90 degrees Fahrenheit) above 30-year average for December.
Southern Hemisphere: +0.33 C (about 0.59 degrees Fahrenheit) above 30-year average for December.
Tropics: +0.26 C (about 0.47 degrees Fahrenheit) above 30-year average for November.

Global Temperature Report: November 2017

by UAH and Dr. J. Christy in A. Watts, December 4, 2014 in WUWT


The average global temperature drop between October and November, 2017, tied for the fifth largest one-month-to-the-next drop in the 39-year satellite temperature record, according to Dr. John Christy, director of the Earth System Science Center (ESSC) at The University of Alabama in Huntsville. Compared to seasonal norms, the average temperature around the globe fell 0.27 C (almost 0.49 degrees F) between October and November. (The largest drop was from January to February 2013, when the global average temperature fell 0.32 C.)

German Scientists Call Recent Sea Level Rise Claims “Fijigate”, …Hyped Up To Generate Money

by Dr. Sebastian Lüning and Prof. Fritz Vahrenholt, November 15, 2017 in  NoTricksZone


After a peak in 2012 the level went down by about 10 cm by mid 2017. It is very much related to natural variations, in sync with the El Ninos (low levels) and La Ninas (high levels).

So what remains of the climate change horror stories in connection to the Fiji Islands? (…)

What do we know about Arctic sea ice trends?

by Dr. Ronan Connolly & Dr. Michael Connolly, August 16, 2017 in WUWT

Satellite observations indicate that the average Arctic sea ice extent has generally decreased since the start of the satellite records in October 1978. Is this period long enough to assess whether the current sea level trend is unusual, and to what extent the decline is caused by humans?

This change in Arctic climate is often promoted as evidence that humans are causing drastic climate change. For instance, an April 29th 2017 article in the Economist (“Skating on thin ice”, pg 16) implied that the Arctic is melting unusually, dramatically and worryingly (…)


 

Des corrections aux données satellitaires augmentent de 140% le réchauffement : le commentaire de Roy Spencer

by Uzbek, 7 juillet 2017 in ClimatoRéalistes


Le site carbonbrief  a publié le 30 juin 2017 un article sous le titre : « Des corrections majeures aux données satellitaires augmentent de 140% le réchauffement depuis 1998[1] »

Précisons d’abord que Les satellites ne mesurent pas directement la température. Ils sont équipés de capteurs sensibles à la luminance de l’atmosphère et de la mer dans le spectre des infrarouges.  Pour en dériver  la température, des traitements informatiques sur les données brutes sont nécessaires.

Satellite battle: Five reasons UAH is different (better) to the RSS global temperature estimates

by JoNova, July 10, 2017


There are two main groups that use essentially the same NASA and NOAA satellites to estimate global temperatures. In the last year, they’ve both made adjustments, one down, and one up, getting further apart in their estimates. In ClimateWorld this is a big deal. Believers are excited that now a satellite set agrees a bit better with the maligned “hot” surface thermometers. But UAH still agrees more with millions of weather balloons. The debate continues. Here’s my short synopsis of the  Roy Spencer (and John Christy) from the “Comments on the new RSS lower tropospheric temperature set.” (If something is wrong here, blame me).

RSS Adjust Their Temperatures–Guess Which Way?

by  Paul Homewood, June 30, 2017


For years, RSS have been an embarrassment to the climate establishment. Their satellite data has consistently shown the pause in global temperatures since 1998, which so many scientists have attempted to explain.

At the same time, the surface datasets of GISS, NOAA and HADCRUT have diverged, with the help of adjustments, to show much greater warming.

The pressure on RSS to conform has been immense, and now the inevitable has happened. Highly conveniently they have found huge errors in their previous version, and have now adjusted to a new version, v4, which miraculously finds that global warming has continued unabated after all!

Elévation du niveau de la mer : la précision millimétrique des observations satellitaires est-elle crédible ?

by ‘Uskek’ , 16 juin 2017, in Climato-Réalistes


Les mesures satellitaires  prétendent mesurer l’élévation du niveau de la mer avec une précision millimétrique. Or La précision des radars altimétriques s’exprime en centimètres. Comment  dans ces conditions parvient-on à mesurer un taux d’élévation du niveau de la mer de 3,4 mm par an sur la période 1993-2015 ?