Saturday, July 8, 2017

Not as hot June troposphere temperatures, with a new version from RSS

Sou | 7:03 PM Go to the first of 14 comments. Add a comment
The troposphere temperatures for June 2017 are out. This report covers the lower troposphere as recorded in UAH v6 and the new RSS TLT v4, and RSS TTT v4 for the troposphere (without the "lower"). It follows pretty much the same format as previous monthly updates.

The troposphere is the part of the atmosphere directly above the surface. The temperatures are estimated from measurements recorded by satellites orbiting the earth.  They are not direct temperature measurements (the satellites don't record thermometer readings). And they are of an average of a depth of the atmosphere - up to several kilometres above the surface. The different versions of reported satellite temperature data tend to vary more than different versions of surface temperature.

For all three different temperature data sets shown, the 12 months to June 2017 is the second hottest 12 months in the record (comparing similar July-June periods).
  • For RSS TTT (troposphere), June itself was the just the eighth hottest June, with June 1998 the hottest.
  • For RSS TLT (lower troposphere), June was the equal fifth hottest June (with June 2014). June 2016 was the hottest.
  • The lower troposphere (UAH v6) June was the eighth hottest June on record. June 1998 was the hottest.

Troposphere temperature (RSS TTT v4) chart

First here is RSS TTT with the latest dataset, version 4. TTT seems to measure more of the troposphere than TLT (that is, it has a greater vertical profile) with less of the stratosphere than the mid-troposphere data (TMT). It shows a higher rate of warming than RSS v3.3 and higher than UAH. Hover the cursor (arrow) over the plots to see the data points, trend etc.

The chart below is the average of the 12 months to June each year from 1979 through to 2017. The annual averaged anomaly was 0.62 °C, which is 0.10 °C lower than the previous hottest 12 month July-June period that ended in June 2016. The rate of warming is 0.18 °C/decade or 1.8 °C/century.
Figure 1 | Troposphere temperature for 12 months to June (TTT). Anomaly is from the 1979-1998 mean. Data source: RSS

From the RSS website, TTT is derived from TMT and TLS with the formula:

TTT = 1.1*TMT - 0.1*TLS. 

This combination reduces the influence of the lower stratosphere, which is cooling at most locations. TLT gives most weight to the temperatures closer to the surface. TTT gives more weight to the troposphere and less to the stratosphere than TMT does, but not as much to the lowest levels of the troposphere as TLT does. For a fuller explanation see the RSS website or the July 16 report here.

Below is the TTT chart just for the month of June. The anomaly for June was 0.39 °C, which is 0.29 °C cooler than June 1998. The rate of warming just for the month of June is 0.16 °C/decade.
Figure 2 | Troposphere temperature for the month of June only (TTT). Anomaly is from the 1979-1998 mean. Data source: RSS

Lower troposphere - RSS TLT version 4

As you might have read, RSS has just released version 4 of the RSS TLT dataset. For more information see the FAQ (and this HotWhopper article about v4 for TTT). Unlike the TTT data (above), TLT is just for the lower troposphere. The chart below is the average for each 12 month period ending in June each year (1979 to 2017). The 12 months to June 2017 is 0.59 °C for RSS TLT, which is the second hottest July-June period on record, 0.15 °C lower than the 12 months ending in June 2016.
Figure 3 | Lower troposphere temperature for 12 months to June. Anomaly is from the 1979-1998 mean. Data source:  RSS

Below is the RSS TLT chart for the month of June only for each year going back to 1979. The anomaly was 0.49 °C above the 1979-1998 mean, which was the equal fifth warmest June in the record, and 0.13 °C cooler than the hottest June in 2016.

Figure 4 | Lower troposphere temperature for the month of June only. Anomaly is from the 1979-1998 mean. Data sources: RSS

Lower troposphere - UAH version 6

The final two charts are from UAH v6. UAH uses a different baseline to RSS. It shows anomalies from the 1981 to 2010 mean, which is higher than the RSS baseline of the 1979 to 1998 average.

UAH has also adjusted the temperature anomalies, with several past temperatures now slightly warmer than were reported in previous months. (The full set of UAH changes aren't yet available.)

The chart below is the average for each 12 month period ending in June each year (1979 to 2017). The 12 months to June 2017 is 0.36 °C for UAH, which is the second hottest July-June period on record, 0.10 °C lower than the 12 months ending in June 2016.
Figure 5 | Lower troposphere temperature for 12 months to June. Anomaly is from the 1981-2010 mean. Data sources: UAH

Below is the UAH chart for the month of June only for each year going back to 1979. The anomaly was 0.21 °C above the 1981-2010 mean, which was the eighth warmest June in the record, and 0.36 °C cooler than the hottest June in 1998.

Figure 6 | Lower troposphere temperature for the month of June only. Anomaly is from the 1981-2010 mean. Data sources: UAH


  1. The thing that stands out in all the data - surface temperature, tropospheric, ocean surface, sea ice volume, etc., is that the trends are firmly saying the same thing. It's extraordinary that after decades of statistics supporting the physics, we still have to defend against the cherry pickers who are desperately looking for some smoke and mirrors with which to blanket their dross.

    It green jellybeans all over again.

  2. Great cartoon making a good statistical point!

    Mind you it is true in this case and here is the proof:

    Green jelly beans are bad for you!

  3. Off topic, but I am sure everyone hopes Anthony takes care to avoid the ill effects of excessive temperatures.

    Southern Californians have flocked to beaches and have gone in search of water, shade and air conditioning to escape the excessive heat.

    1. I'm sure Watts et al. will simply blame the urban heat island effect or suchlike.


    2. Thing is, when they are earnestly preparing for an ice age, a record heat wave is likely to catch citizen scientists wrong footed.

  4. I apologize for having to delete two previous comments. I'm trying to get this right.

    I've noticed denier websites are all a-twitter about the "massive drop" in temperature from May to June.

    I've tried to explain how, well duh, the 2016 El Nino is done, which means temperature (for example, in the UAH TLT data set) is now back to where it was in December of last year, which is hardly a surprise (El Ninos, after all, are temporary transient phenomena).

    But they're not having any of that. Global temps are falling don't'cha know, and no one knows how much farther they're going to fall!

    So, to be helpful, I took the UAH TLT data set and projected out what global temperature is likely to do over the next few months. Feel free to use this graph.

  5. Remember the "pause"? Deniers claim it's back.

    See, some catastrophic event happened sometime in the late 1990s to make the Earth's temperature stop its meteoric rise it had been on since the 1970s. Some incredible event that no one noticed. We'll call this the Great Invisible Temperature Blockage.

    Last time we heard Monckton pretending there was a "pause" was around November of 2015 (if someone has a more recent link, someone let me know). Back then, he claimed the "pause" began in February of 1997, and the Earth's temperature had remained constant (in spite of wandering up and down) until late 2015. So back then, the Great Invisible Temperature Blockage happened in February of 1997.

    Deniers are now claiming the "pause" has returned! But now it started in September of 1997. Somehow, the 2016 El Nino reached back in time and moved the Great Invisible Temperature Blockage to September of 1997. No clue how that happened. Maybe someone can figure it out.

  6. My above two comments were based on a year-old denier article from July of 2016. It was amusing to go back in time and see how well their arguments stood up. They didn't stand at all.

  7. OT: Took a break from Wimbledon to watch another kind of tennis

    Service: MIT president Rafael Reif posts an open letter to his community, deploring Trump's decision to withdraw the US from the Paris climate accords.

    At MIT, we take great care to get the science right. The scientific consensus is overwhelming: As human activity emits more greenhouse gases into the atmosphere, the global average surface temperature will continue to rise, driving rising sea levels and extreme weather.

    Return: A professor of medicine, a professor of marketing, the self-styled 'statisician to the stars', a business researcher, a physicist, a sole climatologist, and Christopher Monckton, special advisor to British Prime Minister Margaret Thatcher, compose a response, based on 'real science' posted at WUWT, sample:

    There is no science unambiguously establishing that the tiny portion of carbon dioxide (CO2) in our Earth’s atmosphere (400 parts per million or 0.04%) is the primary cause of the warming observed since the Little Ice Age ended in the mid-nineteenth century. In fact, science has repeatedly demonstrated he opposite, while also showing the benefits of more carbon dioxide and warming.

    Volley: Maria T. Zuber, Vice President for Research, E.A. Griswold Professor of Geophysics, responds to the response

    Based on the hundreds of conversations that I have had with faculty, students, alumni, and researchers, these statements reflect the consensus view within the MIT community — a consensus grounded in the compelling body of scientific evidence regarding anthropogenic climate change. For example, 22 faculty members from MIT’s Department of Earth, Atmospheric, and Planetary Sciences recently wrote:

    The risks to the Earth system associated with increasing levels of carbon dioxide are almost universally agreed by climate scientists to be real ones. These include, but are not limited to, sea level rise, ocean acidification, and increases in extreme flooding and droughts, all with serious consequences for mankind.

    In summary, we have found strong consensus within the MIT community that the scientific evidence of anthropogenic climate change is compelling; that the risks posed by climate change warrant global action; and that the Paris Agreement represents an important step toward greater global cooperation in responding to this challenge.

    But Monckton's backhand sends the ball smashing into the net:

    There is a natural greenhouse effect, which drives the difference of 33 K between the mean emission temperature of the Earth (255 K) and the mean surface temperature (288 K). That greenhouse effect comprises partly the consequence of forcings and partly the consequence of feedbacks. Assume ad argumentum (and per impossibile) that the 33 K natural greenhouse effect comprises entirely feedbacks.

    You will agree, I think, that the feedbacks acting on today’s climate (before any perturbation by us) cannot by any stretch of the imagination exceed the entire natural greenhouse effect, for otherwise they would be by some magical process materially influencing the Sun itself. Accordingly, elementary feedback theory stipulates that the feedback fraction f, which is the fraction of today’s 288 K surface temperature that is fed back, cannot exceed 33/288, or 0.11, and it is most unlikely to be this large.

    IPCC, however, says reference warming ΔTs in response to doubled CO2 before feedbacks will be 1.2 K, but that equilibrium warming ΔT after feedbacks will fall on [1.5, 4.5] K, implying that its feedback fraction f = (1 – ΔTs/ΔT) will fall on [0.23, 0.74]. But that interval is between twice and seven times the absolute maximum possible value of f, and two orders of magnitude greater than any realistic value.

    Feedbacks are small because I say so. QED.

    1. I seem to recall Monckton was part of a team who wrote a paper proving climate is very stable if you start your analysis by assuming climate is very stable.

    2. How is a feedback fraction of 288 supposed to affect our climate again? How is it related to reference warming delta T? I see a man dealing from the bottom of the deck, and what I would like to see is someone there catching him doing it. What is in the denominator?!! delta or absolute T?

  8. A rinkful of hockey sticks from the PAGES2k Consortium:


    and almost as many independent proxies.

    "A global multiproxy database for temperature reconstructions of the Common Era..." There will be apoplexy and flying shit. And that's just after they read the title...

    1. In R, the workspace contains only the single 16 mb variable--well list--D. But what a variable! Understanding it is not going to be any sort of a quick task!


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