Archives par mot-clé : Temperature

Analysis of new NASA AIRS study: 80% of U.S. Warming has been at Night

by Dr. Roy Spencer, April 30, 2019 in WUWT


I have previously addressed the NASA study that concluded the AIRS satellite temperatures “verified global warming trends“. The AIRS is an infrared temperature sounding instrument on the NASA Aqua satellite, providing data since late 2002 (over 16 years). All results in that study, and presented here, are based upon infrared measurements alone, with no microwave temperature sounder data being used in these products.

That reported study addressed only the surface “skin” temperature measurements, but the AIRS is also used to retrieve temperature profiles throughout the troposphere and stratosphere — that’s 99.9% of the total mass of the atmosphere.

Since AIRS data are also used to retrieve a 2 meter temperature (the traditional surface air temperature measurement height), I was curious why that wasn’t used instead of the surface skin temperature. Also, AIRS allows me to compare to our UAH tropospheric deep-layer temperature products.

So, I downloaded the entire archive of monthly average AIRS temperature retrievals on a 1 deg. lat/lon grid (85 GB of data). I’ve been analyzing those data over various regions (global, tropical, land, ocean). While there are a lot of interesting results I could show, today I’m going to focus just on the United States.

The Relationship between Atmospheric Carbon Dioxide Concentration and Global Temperature for the Last 425 Million Years

by William J. Davis, September 2017, in ResearchGate


Assessing human impacts on climate and biodiversity requires an understanding of the relationship between the concentration of carbon dioxide (CO2) in the Earth’s atmosphere and global temperature (T). Here I explore this relationship empirically using comprehensive, recently-compiled databases of stable-isotope proxies from the Phanerozoic Eon (~540 to 0 years before the present) and through complementary modeling using the atmospheric absorption/transmittance code MODTRAN. Atmospheric CO2 concentration is correlated weakly but negatively with linearly-detrended T proxies over the last 425 million years.

UAH, RSS, NOAA, UW: Which Satellite Dataset Should We Believe?

by Dr Roy Spencer, April 23, 2019 in GlobalWarming


This post has two related parts. The first has to do with the recently published study of AIRS satellite-based surface skin temperature trends. The second is our response to a rather nasty Twitter comment maligning our UAH global temperature dataset that was a response to that study.

Furthermore, that period (January 2003 through December 2017) shows significant warming even in our UAH lower tropospheric temperature (LT) data, with a trend 0.01 warmer than the “gold standard” HadCRUT4 surface temperature dataset (all deg. C/decade):

AIRS: +0.24
GISTEMP: +0.22
ECMWF: +0.20
Cowtan & Way: +0.19
UAH LT: +0.18
HadCRUT4: +0.17

I’m pretty sure the Susskind et al. paper was meant to prop up Gavin Schmidt’s GISTEMP dataset, which generally shows greater warming trends than the HadCRUT4 dataset that the IPCC tends to favor more. It remains to be seen whether the AIRS skin temperature dataset, with its “clear sky bias”, will be accepted as a way to monitor global temperature trends into the future.

What Satellite Dataset Should We Believe?

Greenland Temperature Data For 2018

by P. Homewood, April 24, 2019 in NotaLotOfPeopleKnowThat


The DMI has just published its Greenland Climate Data Collection for last year, and it is worth looking at the temperature data:

There are six stations with long records, Upernavik, Nuuk, Ilulissat, Qaqortoq, Narsarsuaq and Tasilaq.

Throughout Greenland we find that temperatures in the last two decades are little different to the 1920s to 60s.

The only exceptions were 2010 on the west coast sites, which was an unusually warm year, and 2016 on the east coast at Tasilaq, another warm year there.

Noticeably, last year was actually colder than the 1981-2010 average at all of the west and south coast stations.

 

Le CO2 belge : que représente-il vraiment ?

by Jean N., 17 avril 2019 in Science-Climat-Energie


Cet article s’inscrit dans le cadre de l’activité actuelle médiatique tout azimut en Belgique, notamment relayée par les marches hebdomadaires des étudiants pour le climat. Comme vous le savez peut-être si vous êtes un lecteur fidèle de SCE, nous avons démontré dans plusieurs articles que l’hypothèse de l’effet de serre radiatif ne tient pas la route (ici, ici et ici) et n’explique pas le léger réchauffement actuel de la basse atmosphère. Les fins connaisseurs savent également qu’il existe de nombreuses publications scientifiques remettant en cause l’hypothèse de l’effet de serre radiatif (plus de 500 publications rien que pour 2018), toutes écrites par des physiciens, des chimistes, des géologues ou des climatologues. Si cette somme d’évidences vous a convaincu, le GIEC aurait alors tort sur toute la ligne et le CO2 d’origine anthropique n’aurait aucun rôle majeur déterminant la température de la basse troposphère. Cependant, admettons un instant que vous ne soyez pas convaincu et admettons donc que le GIEC ait raison. Tout ce qui est écrit dans son dernier rapport spécial devrait alors être vrai… Quelle serait alors la part de la Belgique dans le réchauffement? Asseyez-vous pour ne pas tomber, vous allez être surpris.

Figure 1. Extrait de la Figure SPM.1 du résumé pour décideurs (SPM) du rapport spécial publié par le GIEC fin 2018. Cette figure se trouve en page 8 du rapport du GIEC.

Predicting heat waves? Look half a world away

University of California – Davis, April 12, 2019 in ScienceDaily


When heavy rain falls over the Indian Ocean and Southeast Asia and the eastern Pacific Ocean, it is a good indicator that temperatures in central California will reach 100°F in four to 16 days, according to a collaborative research team from the University of California, Davis, and the Asia-Pacific Economic Cooperation (APEC) Climate Center in Busan, South Korea.

The results were published in Advances in Atmospheric Scienceson April 12.

FROM PREDICTION TO PROTECTION

Heat waves are common in the Central California Valley, a 50-mile-wide oval of land that runs 450 miles from just north of Los Angeles up to Redding. The valley is home to half of the nation’s tree fruit and nut crops, as well as extensive dairy production, and heat waves can wreak havoc on agricultural production. The dairy industry had a heat wave-induced economic loss of about $1 billion in 2006, for instance. The ability to predict heat waves and understand what causes them could inform protective measures against damage.


Scientists Document No Clear Warming Role For CO2 During The Last Deglaciation – Or The Last 10,000 Years

by K. Richard, April 4, 2019 in NoTricksZone


A new paper indicates the rise in CO2 concentration occurred well after the Northern Hemisphere’s ocean circulation changes drove the abrupt warming (~11,700 years ago) that ended the last ice age – a lag that effectively leaves no causal role for CO2 during deglaciation.

 

Australia Surface Temperatures Compared to UAH Satellite Data Over the Last 40 Years

by Roy Spencer, April 3, 2019 in GlobalWarming


Summary: The monthly anomalies in Australia-average surface versus satellite deep-layer lower-tropospheric temperatures correlate at 0.70 (with a 0.57 deg. C standard deviation of their difference), increasing to 0.80 correlation (with a 0.48 deg. C standard deviation of their difference) after accounting for precipitation effects on the relationship. The 40-year trends (1979-2019) are similar for the raw anomalies (+0.21 C/decade for Tsfc, +0.18 deg. C for satellite), but if the satellite and rainfall data are used to estimate Tsfc through a regression relationship, the adjusted satellite data then has a reduced trend of +0.15 C/decade. Thus, those who compare the UAH monthly anomalies to the BOM surface temperature anomalies should expect routine disagreements of 0.5 deg. C or more, due to the inherently different nature of surface versus tropospheric temperature measurements.

Conclusions

The UAH tropospheric temperatures and BOM surface temperatures in Australia are correlated, with similar variability (0.70 correlation).
Accounting for anomalous rainfall conditions increases the correlation to 0.80. The Tsfc trends have a slightly greater warming trend than the tropospheric temperatures, but the reasons for this are unclear. Users of the UAH data should expect monthly differences between the UAH and BOM data of 0.6 deg. C or so on a rather routine basis (after correcting for their different 30-year baselines used for anomalies: BOM uses 1961-1990 and UAH uses 1981-2010).

The Little Ice Age – Back to the Future

by Jim Steele, April 4, 2019 in WUWT


Extreme scientists and politicians warn we will suffer catastrophic climate change if the earth’s average temperature rises 2.7°F above the Little Ice Age average. They claim we are in a climate crisis because average temperature has already warmed by 1.5°F since 1850 AD. Guided by climate fear, politicians fund whacky engineering schemes to shade the earth with mirrors or aerosols to lower temperatures. But the cooler Little Ice Age endured a much more disastrous climate.

The Little Ice Age coincides with the pre-industrial period. The Little Ice Age spanned a period from 1300 AD to 1850 AD, but the exact timing varies. It was a time of great droughts, retreating tree lines, and agricultural failures leading to massive global famines and rampant epidemics. Meanwhile advancing glaciers demolished European villages and farms and extensive sea ice blocked harbors and prevented trade.

CBC Claims Canada Warming Twice As Fast As Globe, Yet Data Tell A Different Story: No Warming In 25 Years!

by P. Gosselin, April 3, 2019 in NoTricksZone


Canada’s CBC here recently cited “a leaked report” which claimed Canada is “warming at twice the global rate.”

According to the “leaked report”, Canada’s annual average temperature over land has warmed 1.7 C when looking at the data since 1948. But that claim is misleading when recent data is considered.

Over the past 25 years, since scientists began to warn that the planet was warming in earnest, there has not been any warming when one looks at the untampered data provided by the Japan meteorology Agency (JMA) that were measured by 9 different stations across Canada. These 9 stations have the data dating back to around 1983 or 1986, so I used their datasats.

Looking at the JMA database and plotting the stations with longer term recording, we have the following chart:

Sizzling March?

by P. Homewood, April 3, 2019 in NotaLotofPeopleKnowThat


According to CET, March 2019 was the 17th warmest on record since 1659, 1.2C higher than the 1981-2010 average.

Sound impressed? No, thought not!

The month as a whole actually seemed to be pretty unremarkable. There was some mild weather at the start of the month, accompanied by very wet weather. The last few days were also pleasant and sunny.

But unusually warm?

The graph at the top gives a bit of perspective.

First of all it is obvious that last month was pretty typical of Marchs during the last 30 years or so.

The fact that it is 1.2C above the 30-year average means little, as natural variability means some years are warmer and others cooler, such as last year. That’s what an average is.

Indeed, in the last 30 years, eleven had March anomalies of 1C or more. Six of these years were warmer than this March.

By far the warmest Marchs were in 1957 and 1938, again suggesting that there was nothing unusual about last month.

 

The other thing which stands out is that most Marchs used to be much colder than normal until the 1980s.

https://www.metoffice.gov.uk/hadobs/hadcet/cetmaxdly1878on_urbadj4.dat

see also here (WUWT)

Fabricating A Warming: NASA Now Altering ‘Unadjusted” Data To Create New, Warmer ‘Unadjusted’ Data

by P. Gosselin, March 31, 2019 in NoTricksZone


By Kirye

and Pierre Gosselin

One fellow climate blogger recently wrote on how he’s been been looking at GHCN ‘unadjusted’ data and noticed that scientists at NASA appear to have been altering them: “This is a fairly disturbing development,” he wrote.

Heating up Reykjavik and Nuuk

Cited as an example is Reykyavik, Iceland. According to Tony Heller here, “The current version V4 has massively cooled the past, to make it look like Iceland is warming.”

Heller then posted a chart showing the difference between v2 unadjusted and the new v4 ‘unadjusted’ for the Reykjavik station.

 

Spreadsheet

Heller also found here that the same appears to be the case for Nuuk, Greenland as well.

New paper: Urbanization has increased minimum temperatures 1.7K in the UK

by Ian L.M. Goddard & S. Bett, Marcy 21, 2019 in WUWT


Abstract

This study aims to estimate the affect of urbanisation on daily maximum and minimum temperatures in the United Kingdom. Urban fractions were calculated for 10 km × 10 km areas surrounding meteorological weather stations. Using robust regression a linear relationship between urban fraction and temperature difference between station measurements and ERA‐Interim reanalysis temperatures was estimated.

For an urban fraction of 1.0, the daily minimum 2‐m temperature was estimated to increase by 1.90 ± 0.88 K while the daily maximum temperature was not significantly affected by urbanisation. This result was then applied to the whole United Kingdom with a maximum T min urban heat island intensity (UHII) of about 1.7K in London and with many UK cities having T min UHIIs above one degree.

This paper finds through the method of observation minus reanalysis that urbanisation has significantly increased the daily minimum 2‐m temperature in the United Kingdom by up to 1.70 K.

Figure 5 Map showing the change in T min due to the urbanisation at the 10 km × 10 km scale over the United Kingdom and Ireland. The colour bar shows the magnitude of the temperature change in K

Nature Unbound III: Holocene climate variability (Part A)

by Javier, April 30, 2017 in ClimateEtc.


First in a two part series on Holocene climate variability.

Summary: Holocene climate is characterized by two initial millennia of fast warming followed by four millennia of higher temperatures and humidity, and a progressively accelerating cooling and drying for the past six millennia. These changes are driven by variations in the obliquity of the Earth’s axis. The four millennia of warmer temperatures are called the Holocene Climatic Optimum which was 1-2°C warmer than the Little Ice Age. This climatic optimum was when global glaciers reached their minimum extent. The Mid-Holocene Transition, caused by orbital variations, brought a change in climatic mode, from solar to oceanic dominated forcing. This transition displaced the climatic equator, ended the African Humid Period and increased El Niño activity.

 

 

Figure 36. Holocene temperature profile. A. Summer (July-August) Central England temperature reconstruction from multiple proxies and sources by H. H. Lamb.Crosses represent dating and temperature uncertainty. Black dots are centennial averages. Red dot is 1900-1965 average. Source: Lamb, H.H. 1977. Climate: Present, past and future. Volume 2. B. Greenland temperature reconstruction based on an average of uplift corrected δ18O isotopic data from Agassiz and Renland ice cores. This average has been corrected for changes in the δ18O of seawater and calibrated to borehole temperature records. Some historical periods are indicated. Source: B. Vinther et al., 2009.

NOAA : “among the eight warmest Februarys on record”

by Tony Heller, March 19, 2019 in TheDeplorableClimSciBLog


NOAA says last month was “among the eight warmest Februarys on record” in much of the Earth.

According to NCEI’s Regional Analysis, South America, Europe and Oceania had a February temperature that ranked among the eight warmest Februarys on record.

There is no such word as “Februarys” – plural for February is Februaries. But besides the fact they are illiterate, they are also lying

It looks like the world is burning up, with just a few slightly cool areas. It has an official government seal on it, so it must be accurate, right?

The map below shows where NOAA actually had surface temperatures in February.