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Observations of anthropogenic global warming

Archive for October, 2009

Papers on atmospheric measurements of GHGs

Posted by Ari Jokimäki on October 5, 2009

This list of papers contains atmospheric measurements of the absorption properties of greenhouse gases. While many of the papers listed here discuss also carbon dioxide along with other gases, the papers devoted to carbon dioxide will have their own list, so they are not included here. The list is not complete, and will most likely be updated in the future in order to make it more thorough and more representative. The quotes or comments I’m including for each paper are not always exactly representative of the paper as a whole (you usually can’t do that with couple of sentences), because I only try to give the main point of the paper as briefly as I can, so if you are interested in the subject, click the given PDF links for the full story.

UPDATE (May 16, 2012): Ivy et al. (2012) added to general papers section.
UPDATE (December 9, 2011): Garcia et al. (2011) added to general papers section.
UPDATE (November 20, 2011): Wassman et al. (2011) added to ozone section.
UPDATE (April 27, 2010): Coheur et al. (2003) added and the list sorted.
UPDATE (April 14, 2010): Roberts et al. (1976) added.
UPDATE (January 26, 2010): Gurney et al. (1988) added.
UPDATE (December 9, 2009): Liu et al. (2005) added.
UPDATE (October 8, 2009): Hartmann (2008) lecture material added. Three papers by Adel & Lampland (1940) added.

Sublists in this category

Atmospheric carbon dioxide concentration measurements
CO2 records from ice cores
Atmospheric CO2 from proxies
1940s dip in atmospheric CO2
Atmospheric water vapor
Stratospheric water vapor
Water vapor feedback observations
Atmospheric methane concentration
N2O atmospheric concentration
Halocarbon concentrations in the atmosphere

Studies of several gases and other general papers

Atmospheric histories and growth trends of C4F10, C5F12, C6F14, C7F16 and C8F18 – Ivy et al. (2012) “Atmospheric observations and trends are presented for the high molecular weight perfluorocarbons (PFCs): decafluorobutane (C4F10), dodecafluoropentane (C5F12), tetradecafluorohexane (C6F14), hexadecafluoroheptane (C7F16) and octadecafluorooctane (C8F18). Their atmospheric histories are based on measurements of 36 Northern Hemisphere and 46 Southern Hemisphere archived air samples collected between 1973 to 2011 using the Advanced Global Atmospheric Gases Experiment (AGAGE) “Medusa” preconcentration gas chromatography-mass spectrometry systems. A new calibration scale was prepared for each PFC, with estimated accuracies of 6.8% for C4F10, 7.8% for C5F12, 4.0% for C6F14, 6.6% for C7F16 and 7.9% for C8F18. Based on our observations the 2011 globally averaged dry air mole fractions of these heavy PFCs are: 0.17 parts-per-trillion (ppt, i.e., parts per 1012) for C4F10, 0.12 ppt for C5F12, 0.27 ppt for C6F14, 0.12 ppt for C7F16 and 0.09 ppt for C8F18. These atmospheric mole fractions combine to contribute to a global average radiative forcing of 0.35 mW m−2, which is 6% of the total anthropogenic PFC radiative forcing (Montzka and Reimann, 2011; Oram et al., 2012). The growth rates of the heavy perfluorocarbons were largest in the late 1990s peaking at 6.2 parts per quadrillion (ppq, i.e., parts per 1015) per year (yr) for C4F10, at 5.0 ppq yr−1 for C5F12 and 16.6 ppq yr−1 for C6F14 and in the early 1990s for C7F16 at 4.7 ppq yr−1 and in the mid 1990s for C8F18 at 4.8 ppq yr−1. The 2011 globally averaged mean atmospheric growth rates of these PFCs are subsequently lower at 2.2 ppq yr−1 for C4F10, 1.4 ppq yr−1 for C5F12, 5.0 ppq yr−1 for C6F14, 3.4 ppq yr−1 for C7F16 and 0.9 ppq yr−1 for C8F18. The more recent slowdown in the growth rates suggests that emissions are declining as compared to the 1980s and 1990s.” Ivy, D. J., Arnold, T., Harth, C. M., Steele, L. P., Mühle, J., Rigby, M., Salameh, P. K., Leist, M., Krummel, P. B., Fraser, P. J., Weiss, R. F., and Prinn, R. G.: Atmospheric histories and growth trends of C4F10, C5F12, C6F14, C7F16 and C8F18, Atmos. Chem. Phys., 12, 4313-4325, doi:10.5194/acp-12-4313-2012, 2012. [Full text]

Near infrared nadir retrieval of vertical column densities: methodology and application to SCIAMACHY – Garcia et al. (2011) “Nadir observations with the shortwave infrared channels of SCIAMACHY on-board the ENVISAT satellite can be used to derive information on atmospheric gases such as CO, CH4, N2O, CO2, and H2O. For the operational level 1b-2 processing of SCIAMACHY data, a new retrieval code BIRRA (Beer InfraRed Retrieval Algorithm) has been developed. BIRRA performs a nonlinear or separable least squares fit (with bound constraints optional) of the measured radiance, where molecular concentration vertical profiles are scaled to fit the observed data. Here we present the forward modeling (radiative transfer) and inversion (least squares optimization) fundamentals of the code along with the further processing steps required to generate higher level products such as global distributions and time series. Moreover, various aspects of level 1 (observed spectra) and auxiliary input data relevant for successful retrievals are discussed. BIRRA is currently used for operational analysis of carbon monoxide vertical column densities from SCIAMACHY channel 8 observations, and is being prepared for methane retrievals using channel 6 spectra. A set of representative CO retrievals and first CH4 results are presented to demonstrate BIRRA’s capabilities.” Gimeno García, S., Schreier, F., Lichtenberg, G., and Slijkhuis, S., Atmos. Meas. Tech., 4, 2633-2657, doi:10.5194/amt-4-2633-2011, 2011. [Full text]

Quantifying sources and sinks of trace gases using space-borne measurements: current and future science – Palmer (2008) “First, I briefly review the theory behind measuring the atmosphere from space, and how these data can be used to infer surface sources and sinks of trace gases. I then present some of the science highlights associated with these data and how they can be used to improve fundamental understanding of the Earth’s climate system. I conclude the paper by discussing the future role of satellite measurements of tropospheric trace gases in mitigating surface air pollution and carbon trading.” [Full text]

Nadir measurements of the Earth’s atmosphere with the ACE FTS: first results – Evans et al. (2008) “Nadir spectra obtained with the ACE FTS are presented and analyzed for methane, ozone and nitrous oxide.” [Full text]

The REFIR-PAD experiment – Palchetti et al. (2008) “The spectrally resolved measurement of the upwelling radiation emitted from the Earth over the relevant spectral region from the far-infrared (FIR) to the mid-infrared is expected to improve the characterisation of the Earth radiation budget as a function of the atmospheric components that are responsible for this emission. In particular, the effect of water vapour in the upper troposphere and of thin clouds as cirrus can be characterised by taking advantage of their FIR signatures.” [Full text]

The Far-infrared Earth – Harries et al. (2008) “The paper presents a review of the far-infrared (FIR) properties of the Earth’s atmosphere and their role in climate. These properties have been relatively poorly understood, and it is one of the purposes of this review to demonstrate that in recent years we have made great strides in improving this understanding.”

A strict test in climate modeling with spectrally resolved radiances: GCM simulation versus AIRS observations – Huang et al. (2007) “The spectrally resolved infrared radiances observed by AIRS provide a strict and insightful test for general circulation models (GCMs). We compare the clear- and total- sky spectra simulated from the Geophysical Fluid Dynamics Laboratory GCM using a high resolution radiation code with the AIRS observations. After ensuring consistency in the sampling of the observed and simulated spectra and a proper representation of clouds in the radiance simulation, the observed and simulated global-mean radiances are shown to agree to within 2 K in the window region.” [Full text]

Remote Sensing of Atmospheric Climate Parameters from the Atmospheric Infrared Sounder – Pagano et al. (2006) “This paper presents the standard and research products from Atmospheric Infrared Sounder (AIRS) and their current accuracies as demonstrated through validation efforts. It also summarizes ongoing research using AlRS data for weather prediction and improving climate models.” [Full text]

AIRS improving weather forecasting and providing new data on greenhouse gases – Chahine et al. (2006) “We describe the science background and the performance of AIRS in terms of the accuracy and stability of its observed spectral radiances. We examine the validation of the retrieved temperature and water vapor profiles against collocated operational radiosondes, and then we assess the impact thereof on numerical weather forecasting of the assimilation of the AIRS spectra and the retrieved temperature. We close the paper with a discussion on the retrieval of several minor tropospheric constituents from AIRS spectra.” [Full text]

Trace gas measurements from infrared satellite for chemistry and climate applications – Clerbaux et al. (2003) Infrared spectrum of Earth measured from a satellite and effects of different greenhouse gases are identified. See their Figure 1 for a very nice and simple presentation. [Full text]

The Retrieval of Planetary Boundary Layer Structure Using Ground-Based Infrared Spectral Radiance Measurements – Smith et al. (1999) You can do atmospheric measurements on ground too. “The surface-based Atmospheric Emitted Radiance Interferometer (AERI) is an important measurement component of the Department of Energy Atmospheric Radiation Measurement Program. The method used to retrieve temperature and moisture profiles of the plantetary boundary layer from the AERI’s downwelling spectral radiance observations is described.” [Full text]

Application of infrared interferometer spectrometer clear sky spectral radiance to investigations of climate variability – Iacono & Clough (1996) It would be nice if papers like this would be freely accessible to everyone. Nice infrared spectrum images here, taken in 1970 from a satellite. This paper would be nice to show to anyone claiming that greenhouse effect doesn’t exist. “Global observations of outgoing longwave radiation during 1970 from the infrared interferometer spectrometer (IRIS) aboard Nimbus 4 cover nearly a full annual cycle, and the spectral content of the data provides unique information for examining regional and seasonal variations of spectral radiance. The IRIS radiances have been validated against a line-by-line radiative transfer model and are found to compare favorably with calculated radiances. … In general, the retrieved seasonal changes in temperature and water vapor parameters are consistent with the known conditions of the 1970 tropical ocean and atmosphere. These variations are detectable as signatures in outgoing spectral radiances and provide significant information relevant to climate change.”

The greenhouse Earth: A view from space – Harries (1996) “The radiative cooling of the Earth in the absence of clouds has recently been shown to be dominated by emission from upper-tropospheric water vapour, in the far infrared portion of the spectrum, and this is illustrated: observations of this radiative flux, and of the distribution of water vapour in the upper troposphere, are urgently needed. The role of clouds is discussed, and it is noted that their response to global warming is not presently unambiguously determined with available models, due to the complexity of competing processes: again, as in the cloud-free case, more accurate global observations are needed. The paper is illustrated by data from satellite experiments, most notably the Earth Radiation Budget Experiment sponsored by NASA.”

Methane and carbon dioxide increases in the urban boundary layer: Inferences from whole‐column infrared absorbance measurements – Gurney et al. (1988) “Using the sun as an infrared source, we determined the total atmospheric column absorbance of methane and carbon dioxide spectral lines in the 8‐ to 10‐µm infrared region. At our laboratory located in an urban region, these absorbances showed fluctuations larger than can be accounted for by known variabilities in the background atmosphere. We interpret these observations in terms of large changes in concentration of methane and carbon dioxide within the urban boundary layer. These increases could affect the radiative balance in urban locations and contribute to the urban heat island.” [Full text]

Atmospheric Absorption of Infrared Solar Radiation at the Lowell Observatory. III and IV. The Spectral Intervals: 8.0-11.0 μ and 11.0-14.0 μ – Adel & Lampland (1940) “The detailed transmission of the earth’s atmosphere throughout the spectral intervals from 8.0 to 11.0 μ and from 11.0 to 14.0 μ is investigated empirically in its dependence upon water vapor, ozone, and carbon dioxide.” [Full text is available in the abstract page]


Ozone profiles from clear sky thermal infrared measurements of the Infrared Atmospheric Sounding Interferometer: A retrieval approach accounting for thin cirrus – Wassman et al. (2011) “In this work we discuss the retrieval of ozone profiles from Infrared Atmospheric Sounding Interferometer (IASI) thermal infrared measurements in the presence of thin cirrus. An algorithm is presented which accounts for optically thin cirrus, described by an absorption layer at fixed altitude, where an effective cirrus optical depth is determined from IASI measurements at the 15 μm CO2 absorption band. Subsequently, the cirrus characteristics are used for the ozone profile retrievals at the 9.6 μm O3 absorption band. To retrieve ozone we employ a Tikhonov regularization scheme in combination with the L curve approach. A sensitivity study shows that neglecting thin cirrus in the ozone profile retrieval leads to errors of >20% in the troposphere for an infrared optical depth of <0.1 (τ550nm < 0.05), while errors are around 5% when accounting for thin cirrus in the proposed manner. Uncertainties on cirrus height are mostly compensated by the retrieval of the effective cloud parameter. The findings are confirmed when we apply the retrieval scheme to IASI measurements which are filtered according to water clouds and optically thick cirrus. The ozone profiles are validated with 193 collocated ozonesonde profiles from nine stations and show good improvement at all altitudes. For the different stations the differences in the mean profiles between IASI ozone profiles and sonde profiles at 5 km altitude improve from (−10)%–(+80)% when cirrus is not accounted for in the retrieval to (−10)%–(+35)% when employing the new retrieval scheme. At the same time the root-mean-square differences between IASI ozone profiles and sonde profiles improve from 30%–100% to 20%–50%.” Wassmann, A., J. Landgraf, and I. Aben (2011), J. Geophys. Res., 116, D22302, doi:10.1029/2011JD016066

Satellite measurements of the clear-sky greenhouse effect from tropospheric ozone – Worden et al. (2008) “Here, we analyse spectrally resolved measurements of infrared radiance from the Tropospheric Emission Spectrometer9 on board the NASA Aura satellite, as well as corresponding estimates of atmospheric ozone and water vapour, to obtain the reduction in clear-sky outgoing long-wave radiation due to ozone in the upper troposphere over the oceans.” [Full text]

Ozone profile and tropospheric ozone retrievals from the Global Ozone Monitoring Experiment: Algorithm description and validation – Liu et al. (2005) “Ozone profiles are derived from back scattered radiance spectra in the ultraviolet (289–339 nm) measured by the Global Ozone Monitoring Experiment (GOME) using the optimal estimation technique.” [Full text]


Spectroscopic measurements of halocarbons and hydrohalocarbons by satellite-borne remote sensors – Coheur et al. (2003) “Infrared spectra recorded by the Atmospheric Trace Molecule Spectroscopy Experiment (ATMOS) and the Interferometric Monitor for Greenhouse Gases (IMG) remote sensors have been analyzed by means of line-by-line radiative transfer calculations in order to evaluate the possibilities offered by solar occultation and by nadir instruments to monitor the cholorofluorocarbons (CFCs) and their substitutes. The reliability of the existing spectroscopic parameters has been examined, and it was found that only laboratory parameters measured at high resolution reproduce the satellite observations well. It is shown that solar occultation spectra can give information regarding the atmospheric abundance of CFC-113, in addition to the usual retrievals of CFC-11, CFC-12 and HCFC-22.” [Full text]

Closely related

Radiative transfer modelling for IASI – Matricardi (2009) Presentation material of IASI atmospheric measurements. Contains lot of interesting commented spectral images. [Full text]

Collisional effects on spectral shapes and remote sensing – Hartmann (2008) Lecture material. Very interesting for those who want to dig deeper into this issue. [Full text]

Fourier Transform Spectroradiometers for the Characterization of the Composition and the Radiative Properties of the Upper Atmosphere – Palchetti et al. (2004) A paper on spectrometer used in atmospheric measurements, including example measurements. [Full text]

Atmospheric Effects on Low-Power Laser Beam Propagation – Tuer et al. (1980) A review article that covers theory, laboratory measurements, and atmospheric measurements. “A detailed discussion is presented of various theories, experiments, and models pertinent to atmospheric effects on the transmission of low-power laser radiation. The effects of molecules, aerosols, and turbulence and their levels in the atmosphere are considered.” [Full text]

These lists contain more atmospheric measurements of GHG’s:
Papers on changes in OLR due to GHG’s
Papers on changes in DLR
Papers on global carbon cycle
Papers on atmospheric carbon dioxide concentration measurements

Also related is this list:
Papers on laboratory measurements of CO2 absorption properties

Posted in AGW evidence | 13 Comments »

Comments on McIntyre’s claims on Briffa

Posted by Ari Jokimäki on October 2, 2009

Those who have followed climate science online have undoubtedly heard about recent claims made by McIntyre about Briffa et al. work on tree ring based reconstructions. Keith Briffa has already responded, and RealClimate has also responded. In addition to these, I have couple of things I would like to point out.

McIntyre started the claims in this post. I’ll quote the first sentence from there:

A few days ago, I became aware that the long-sought Yamal measurement data url had materialized at Briffa’s website – after many years of effort on my part and nearly 10 years after its original use in Briffa (2000).

Note that McIntyre doesn’t give a link to Briffa’s website where Briffa introduces the data, but McIntyre links directly (and only) to the page containing the data. It is of course easy to find it yourself, but it seems to be a common theme in McIntyre’s postings that as little outside information as possible is given. McIntyre also doesn’t give proper reference to Briffa (2000), this has also been left for the reader to find out.

Here is the link to Briffa’s website, where the link to the data page is given:
And the link there leads to more thorough presentation of the data:
There then is the link to the data file McIntyre linked to:

Here is the link and the reference to Briffa (2000):
Briffa, K. R. 2000. Annual climate variability in the Holocene: interpreting the message of ancient trees. Quaternary Science Reviews 19:87-105 (unfortunately this paper doesn’t seem to be freely available online).

Now, looking at Briffa’s website and McIntyre’s quote above, I note that there’s something strange here. McIntyre mentions Briffa (2000) and how it’s been 10 years from that, but there is entirely different paper being given in Briffa’s website:

Briffa et al., 2008 Phil. Trans. R. Soc. B, vol. 363, no. 1501, 2269-2282, “Trends in recent temperature and radial tree growth spanning 2000 years across northwest Eurasia” (click “full text” links on the right to read the whole paper).

So, already the first sentence of McIntyre’s post was false. This is not the data for Briffa (2000) (even if a version of it was used there), but it is the data for Briffa et al. (2008). Briffa et al. (2008) is not discussed by McIntyre, but is mentioned once in the caption of Figure 1:

Figure 1. Comparison of the (smoothed) Yamal reconstruction (Briffa 2000, Briffa et al 2008, Kaufman et al 2009 and many others) to the Polar Urals Update (Esper et al 2002).

It is quite ironic that McIntyre’s Figure 1 only contains two curves, “Briffa (2000)” and “Esper update”. I also wonder what exactly is this “(smoothed) Yamal reconstruction” as McIntyre seems to use only raw data (or at least doesn’t say otherwise) from Briffa et al. (2008). Also, again no proper references for any of the mentioned papers.

So, the data is from Briffa et al. (2008). That means we have to consult Briffa et al. (2008) in order to see what has been the data selection process (which McIntyre didn’t do). On Yamal data, they say:

Siberian larch (Larix sibirica) data from the area immediately east of the northern Ural Mountains, previously used by Hantemirov & Shiyatov (2002), were used as the Yamal regional chronology,…

So, it appears they use data from Hantemirov & Shiyatov (2002). Here is the link to that paper (but not freely accessible for everyone):
Hantemirov & Shiyatov, 2002, The Holocene, Vol. 12, No. 6, 717-726, “A continuous multimillennial ring-width chronology in Yamal, northwestern Siberia”

Curiously enough, McIntyre starts discussing Hantemirov & Shiyatov (2002) paper, and I think he shows that he is not aware that Briffa et al. (2008) used the data of Hantemirov & Shiyatov (2002), McIntyre says:

There is one other version of these series that readers may encounter: Hantemirov and Shiyatov archived a Yamal reconstruction at NCDC that has no hockey stick blade whatever. This version was promoted by a commenter (Lucy Skywalker) at Jeff Id’s as being a priori more valid than Briffa’s. Although the Hantemirov and Briffa chronologies have a very different visual appearance (especially the non_HSness of the Hantemirov version), there is an extremely high correlation between the very different looking Hantemirov-Shiyatov and Briffa Yamal chronologies. (If you regress the Briffa recon against the Hantemirov recon for the pre-1800 version, you get a huge r^2 of 0.81). The two series clearly have the same raw material.

That would go without saying, if McIntyre would have looked at Briffa et al. (2008), where he got the data from.

Posted in Climate claims | 10 Comments »

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