New Research

[knocker]

NASA Pinpoints Causes of 2011 Arctic Ozone Hole

Maps of ozone concentrations over the Arctic come from the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite. The left image shows March 19, 2010, and the right shows the same date in 2011. March 2010 had relatively high ozone, while March 2011 has low levels. Credit: NASA/Goddard

A combination of extreme cold temperatures, man-made chemicals and a stagnant atmosphere were behind what became known as the Arctic ozone hole of 2011, a new NASA study finds.

Even when both poles of the planet undergo ozone losses during the winter, the Arctic’s ozone depletion tends to be milder and shorter-lived than the Antarctic’s. This is because the three key ingredients needed for ozone-destroying chemical reactions —chlorine from man-made chlorofluorocarbons (CFCs), frigid temperatures and sunlight— are not usually present in the Arctic at the same time: the northernmost latitudes are generally not cold enough when the sun reappears in the sky in early spring. Still, in 2011, ozone concentrations in the Arctic atmosphere were about 20 percent lower than its late winter average.

http://www.nasa.gov/topics/earth/features/2011-ozone-hole.html

[Gray-Wolf]

http://iopscience.iop.org/1748-9326/8/1/014052

A look at Siberian snow loss over the years.

[Methuselah]

http://phys.org/news...atmosphere.html

New discovery may allow scientists to make fuel from CO2 in the atmosphere

"Basically, what we have done is create a microorganism that does with carbon dioxide exactly what plants do—absorb it and generate something useful," said Michael Adams, member of UGA's Bioenergy Systems Research Institute, Georgia Power professor of biotechnology and Distinguished Research Professor of biochemistry and molecular biology in the Franklin College of Arts and Sciences.

Presumably, that process would require the breaking of two C=O bonds followed by the creation of four C-H plus the hydrolysis of H₂O?? I'm sceptical of its large-scale workability...

[Gray-Wolf]

If it's not been bought up by Koch Bros and co it's a non starter.......

[knocker]

Global ocean storage of anthropogenic carbon

http://www.biogeosciences.net/10/2169/2013/bg-10-2169-2013.pdf

[knocker]

Regional and global projections of twenty-first century glacier mass changes in response to climate scenarios from global climate models

Abstract

A large component of present-day sea-level rise is due to the melt of glaciers other than the ice sheets. Recent projections of their contribution to global sea-level rise for the twenty-first century range between 70 and 180 mm, but bear significant uncertainty due to poor glacier inventory and lack of hypsometric data. Here, we aim to update the projections and improve quantification of their uncertainties by using a recently released global inventory containing outlines of almost every glacier in the world. We model volume change for each glacier in response to transient spatially-differentiated temperature and precipitation projections from 14 global climate models with two emission scenarios (RCP4.5 and RCP8.5) prepared for the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. The multi-model mean suggests sea-level rise of 155 ± 41 mm (RCP4.5) and 216 ± 44 mm (RCP8.5) over the period 2006–2100, reducing the current global glacier volume by 29 or 41 %. The largest contributors to projected global volume loss are the glaciers in the Canadian and Russian Arctic, Alaska, and glaciers peripheral to the Antarctic and Greenland ice sheets. Although small contributors to global volume loss, glaciers in Central Europe, low-latitude South America, Caucasus, North Asia, and Western Canada and US are projected to lose more than 80 % of their volume by 2100. However, large uncertainties in the projections remain due to the choice of global climate model and emission scenario. With a series of sensitivity tests we quantify additional uncertainties due to the calibration of our model with sparsely observed glacier mass changes. This gives an upper bound for the uncertainty range of ±84 mm sea-level rise by 2100 for each projection.

http://link.springer.com/article/10.1007%2Fs00382-013-1719-7

[knocker]

Rising temperature difference between hemispheres could dramatically shift rainfall patterns in tropics

BERKELEY —

One often ignored consequence of global climate change is that the Northern Hemisphere is becoming warmer than the Southern Hemisphere, which could significantly alter tropical precipitation patterns, according to a new study by climatologists from the University of California, Berkeley, and the University of Washington, Seattle.

Edited April 3, 2013 by knocker

[knocker]

Independent confirmation of global land warming without the use of station temperatures

Abstract

[1] Confidence in estimates of anthropogenic climate change is limited by known issues with air temperature observations from land stations. Station siting, instrument changes, changing observing practices, urban effects, land cover, land use variations, and statistical processing have all been hypothesized as affecting the trends presented by the Intergovernmental Panel on Climate Change and others. Any artifacts in the observed decadal and centennial variations associated with these issues could have important consequences for scientific understanding and climate policy. We use a completely different approach to investigate global land warming over the 20^th century. We have ignored all air temperature observations and instead inferred them from observations of barometric pressure, sea surface temperature, and sea-ice concentration using a physically-based data assimilation system called the 20^th Century Reanalysis. This independent dataset reproduces both annual variations and centennial trends in the temperature datasets, demonstrating the robustness of previous conclusions regarding global warming.

http://onlinelibrary.wiley.com/doi/10.1002/grl.50425/abstract

[knocker]

Discovery of 1,800-year-old 'Rosetta Stone' for tropical ice cores

Find offers the most complete picture of Earth's low-latitude climate history to date

COLUMBUS, Ohio—Two annually dated ice cores drawn from the tropical Peruvian Andes reveal Earth's tropical climate history in unprecedented detail—year by year, for nearly 1,800 years.

Researchers at The Ohio State University retrieved the cores from a Peruvian ice cap in 2003, and then noticed some startling similarities to other ice cores that they had retrieved from Tibet and the Himalayas. Patterns in the chemical composition of certain layers matched up, even though the cores were taken from opposite sides of the planet.

In the April 4, 2013 online edition of the journal Science Express, they describe the find, which they call the first annually resolved "Rosetta Stone" with which to compare other climate histories from Earth's tropical and subtropical regions over the last two millennia.

The cores provide a new tool for researchers to study Earth's past climate, and better understand the climate changes that are happening today.

"These ice cores provide the longest and highest-resolution tropical ice core record to date," said Lonnie Thompson, distinguished university professor of earth sciences at Ohio State and lead author of the study.

"In fact, having drilled ice cores throughout the tropics for more than 30 years, we now know that this is the highest-resolution tropical ice core record that is likely to be retrieved."

http://www.eurekalert.org/pub_releases/2013-04/osu-do1040113.php

[knocker]

Physical mechanisms of European winter snow cover variability and its relationship to the NAO

Abstract

Annual snow cover in the Northern Hemisphere has decreased in the past two decades, an effect associated with global warming. The regional scale changes of snow cover during winter, however, vary significantly from one region to another. In the present study, snow cover variability over Europe and its connection to other atmospheric variables was investigated using Cyclostationary Empirical Orthogonal Function (CSEOF) analysis. The evolution of atmospheric variables related to each CSEOF mode of snow cover variability was derived via regression analysis in CSEOF space. CSEOF analysis clearly shows that the North Atlantic Oscillation (NAO) is related to European snow cover, particularly in January and February. A negative NAO phase tends to result in a snow cover increases, whereas a positive NAO phase results in snow cover decreases. The temporal changes in the connection between the NAO and European snow cover are explained by time-dependent NAO-related temperature anomalies. If the NAO phase is negative, the temperature is lower in Europe and snow cover increases; by contrast, when the NAO phase is positive, the temperature is higher and snow cover decreases. Temperature and snow cover variations in Europe are associated with the thermal advection by anomalous wind by NAO. CSEOF analysis also shows an abrupt increase of snow cover in December and January and a decrease in February and March since the year 2000, approximately. This abrupt change is associated with sub-seasonal variations of atmospheric circulation in the study region.

http://link.springer.com/article/10.1007%2Fs00382-012-1365-5

[knocker]

Comment on “The phase relation between atmospheric carbon dioxide and global temperature†by Humlum, Stordahl and Solheim

Abstract

Humlum et al, 2012 conclude that the change in atmospheric CO₂ from January 1980 is natural, rather than human induced. However, their use of differentiated time series removes long term trends such that the presented results cannot support this conclusion. Using the same data sources it is shown that this conclusion violates conservation of mass. Furthermore it is determined that human emissions explain the entire observed long term trend with a residual that is indistinguishable from zero, and that the natural temperature-dependent effect identified by Humlum et al is an important contributor to the variability, but does not explain any of the observed long term trend of + 1.7 ppm yr^{- 1}.

http://www.sciencedirect.com/science/article/pii/S0921818113000908

[keithlucky]

Coral reefs recover from mass bleaching http://www.aims.gov....p_p_col_count=3

[knocker]

Antarctic Octopus Living Testament To Global Warming

The octopus, formerly known as both a delicacy food item and for being thrown onto the ice at hockey games, now has a new recognition: a living testament to the effects of global warming.

Genetic information from an Antarctic octopus species adds to a growing body of evidence of at least a partial collapse of the West Antarctic Ice Sheet (WAIS) during a previous interglacial period (like during the Eemian interglacial some 125,000 years ago).

http://www.skepticalscience.com/news.php?n=1940&utm_source=dlvr.it&utm_medium=twitter

[Gray-Wolf]

Another indicator that a period in history with similar GHG concentrations saw the WAIS gone and open water between Ross and Weddell seas.

My belief is that the partial collapse of Ross (Roosevelt Island end) allows for the opening of the channel between both seas and the total meltout of WAIS follows. As such I would encourage folk to watch Ross Embayment esp. the fractures/moulins into Roosevelt Island. Once that swathe of ice has failed gravity , and not temperature, brings aboput the loss of Ross and the separation of west and east Antarctica.

This is another event in most folks (30yrs) lifetime and has 'sudden sea level rise' implications.

Nature does not lie. The findings from molluscs,bivalves and arthropods point to open water connection between Ross and Weddell 125,000yrs ago. GHG's were slightly below the totals we expect this Sept. Go figure.......

[knocker]

Links between multi- and interdecadal climatic oscillations in the North Atlantic and regional climate variability of Northern France and England since the 17^th century

Abstract

[1] Knowledge of the variability of climate in the past is essential for understanding current climatic changes. Therefore, we investigated two temperature indices and seven rainfall time series of North-Western Europe since the 17^th century. Trends and multi- to interdecadal variability are similar in England and Northern France for temperature, whereas a strong regional contrast is evident between the two regions for rainfall. Multi- and interdecadal variabilities display several periods of enhanced amplitude for both temperature and rainfall that may be related to large-scale climate control. On these scales, temperatures in both England and France display phase opposition with the Atlantic Multidecadal Oscillation (AMO) before 1800, while they are in phase afterwards, as determined by wavelet coherence. On the other hand, the relationships between temperature and the North Atlantic Oscillation (NAO) are weak across multi- and interdecadal scales for the whole period under study. For rainfall, coherence with AMO is observed for scales at around 30–60-year, whereas coherence with NAO is detected on 50–80-year and interdecadal 16–23-year scales. However, relationships between rainfall variability and North Atlantic climate indices are highly contrasted depending on the region considered. Finally, the results of a mixed spectral/EOF analysis of mean sea-level pressure on these co-oscillation time scales highlight not only NAO regimes, but also other patterns explaining a non-negligible amount of variance during certain time periods.

http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50392/abstract

Response of the midlatitude jets and of their variability to increased greenhouse gases in the CMIP5 models

Abstract

This work documents how the midlatitude, eddy-driven jets respond to climate change using model output from the Coupled Model Intercomparison Project, Phase 5 (CMIP5). We consider separately the North Atlantic, the North Pacific and the Southern Hemisphere jets. We do not limit our analysis to annual mean changes in the latitude and speed of the jets, but also explore how the variability of each jet changes with increased greenhouse gases.

We find that all jets migrate poleward with climate change: the Southern Hemisphere jet shifts poleward by 2 degrees of latitude between the Historical period and the end of the 21st century in the RCP8.5 scenario, whereas both Northern Hemisphere jets shift by only 1 degree. In addition, the speed of the Southern Hemisphere jet is found to increase markedly (by 1.2 m/s between 850-700 hPa), while the speed remains nearly constant for both jets in the Northern Hemisphere.

More importantly, we find that the patterns of jet variability are a strong function of the jet position in all three sectors of the globe, and as the jets shift poleward the patterns of variability change. Specifically, for the Southern Hemisphere and the North Atlantic jets, the variability becomes less of a north-south wobbling and more of pulsing (i.e. change in jet speed). In contrast, for the North Pacific jet, the variability becomes less of a pulsing and more of a north-south wobbling. These different responses can be understood in terms of Rossby wave breaking, allowing us to explain most of the projected jet changes with a single dynamical mechanism.

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00536.1

[knocker]

Did the Arctic Ice Recover? Demographics of True and False Climate Facts

Abstract

Beliefs about climate change divide the U.S. public along party lines more distinctly than hot social issues. Research finds that better-educated or informed respondents are more likely to align with their parties on climate change. This information–elite polarization resembles a process of biased assimilation first described in psychological experiments. In nonexperimental settings, college graduates could be prone to biased assimilation if they more effectively acquire information that supports their beliefs. Recent national and statewide survey data show response patterns consistent with biased assimilation (and biased guessing) contributing to the correlation observed between climate beliefs and knowledge. The survey knowledge questions involve key, uncontroversial observations such as whether the area of late-summer Arctic sea ice has declined, increased, or declined and then recovered to what it was 30 years ago. Correct answers are predicted by education, and some wrong answers (e.g., more ice) have predictors that suggest lack of knowledge. Other wrong answers (e.g., ice recovered) are predicted by political and belief factors instead. Response patterns suggest causality in both directions: science information affecting climate beliefs, but also beliefs affecting the assimilation of science information.

 

 

http://journals.ametsoc.org/doi/abs/10.1175/WCAS-D-12-00008.1

[Gray-Wolf]

It just appears to confirm that denialists will believe what serves them best , and argue for such, even when the facts on the ground run contrary to that view.

 

Basically we will end up with a portion of 'vested interests' folk, measurably out of stride with reality, as the broader impacts of AGW become ever more apparent?

[knocker]

Recent Trends in Arctic Sea Ice and the Evolving Role of Atmospheric Circulation Forcing,

 

http://www.cgd.ucar.edu/cas/cdeser/Docs/DeserTeng_AGUchapter.pdf

[knocker]

Rapid thinning of lake-calving Yakutat Glacier and the collapse of the Yakutat Icefield, southeast Alaska, USA

Abstract:

Both lake-calving Yakutat Glacier (337 km²), Alaska, USA, and its parent icefield (810 km²) are experiencing strong thinning, and under current climate conditions will eventually disappear. Comparison of digital elevation models shows that Yakutat Glacier thinned at area-averaged rates of 4.76±0.06 m w.e.a^-1 (2000-07) and 3.66±0.03 m w.e.a^-1 (2007-10). Simultaneously, adjacent Yakutat Icefield land-terminating glaciers thinned at lower but still substantial rates (3.79 and 2.94 m w.e.a^-1 respectively for the same time periods), indicating lake-calving dynamics helps drive increased mass loss. Yakutat Glacier terminates into Harlequin Lake and for over a decade sustained a ∼3 km long floating tongue, which started to disintegrate into large tabular icebergs in 2010. Such floating tongues are rarely seen on temperate tidewater glaciers. We hypothesize that this difference is likely due to the lack of submarine melting in the case of lake-calving glaciers. Floating-tongue ice losses were evaluated in terms of overall mass balance and contribution to sea-level rise. The post-Little Ice Age collapse of Yakutat Icefield was driven in part by tidewater calving retreats of adjacent glaciers, the lake-calving retreat of Yakutat Glacier, a warming climate and by the positive feedback mechanisms through surface lowering.

 

 

http://www.ingentaconnect.com/content/igsoc/jog/2013/00000059/00000213/art00015

[knocker]

Recent variability of the solar spectral irradiance and its impact on climate modelling

Abstract.

The lack of long and reliable time series of solar spectral irradiance (SSI) measurements makes an accurate quantification of solar contributions to recent climate change difficult. Whereas earlier SSI observations and models provided a qualitatively consistent picture of the SSI variability, recent measurements by the SORCE (SOlar Radiation and Climate Experiment) satellite suggest a significantly stronger variability in the ultraviolet (UV) spectral range and changes in the visible and near-infrared (NIR) bands in anti-phase with the solar cycle. A number of recent chemistry-climate model (CCM) simulations have shown that this might have significant implications on the Earth's atmosphere. Motivated by these results, we summarize here our current knowledge of SSI variability and its impact on Earth's climate.

We present a detailed overview of existing SSI measurements and provide thorough comparison of models available to date. SSI changes influence the Earth's atmosphere, both directly, through changes in shortwave (SW) heating and therefore, temperature and ozone distributions in the stratosphere, and indirectly, through dynamical feedbacks. We investigate these direct and indirect effects using several state-of-the art CCM simulations forced with measured and modelled SSI changes. A unique asset of this study is the use of a common comprehensive approach for an issue that is usually addressed separately by different communities.

We show that the SORCE measurements are difficult to reconcile with earlier observations and with SSI models. Of the five SSI models discussed here, specifically NRLSSI (Naval Research Laboratory Solar Spectral Irradiance), SATIRE-S (Spectral And Total Irradiance REconstructions for the Satellite era), COSI (COde for Solar Irradiance), SRPM (Solar Radiation Physical Modelling), and OAR (Osservatorio Astronomico di Roma), only one shows a behaviour of the UV and visible irradiance qualitatively resembling that of the recent SORCE measurements. However, the integral of the SSI computed with this model over the entire spectral range does not reproduce the measured cyclical changes of the total solar irradiance, which is an essential requisite for realistic evaluations of solar effects on the Earth's climate in CCMs.

We show that within the range provided by the recent SSI observations and semi-empirical models discussed here, the NRLSSI model and SORCE observations represent the lower and upper limits in the magnitude of the SSI solar cycle variation.

The results of the CCM simulations, forced with the SSI solar cycle variations estimated from the NRLSSI model and from SORCE measurements, show that the direct solar response in the stratosphere is larger for the SORCE than for the NRLSSI data. Correspondingly, larger UV forcing also leads to a larger surface response.

Finally, we discuss the reliability of the available data and we propose additional coordinated work, first to build composite SSI data sets out of scattered observations and to refine current SSI models, and second, to run coordinated CCM experiments.

 

 

http://www.atmos-chem-phys.net/13/3945/2013/acp-13-3945-2013.pdf

Edited April 18, 2013 by knocker

[knocker]

Massive amounts of charcoal enter the worlds' oceans

 

Wild fire residue is washed out of the soil and transported to the sea by rivers

 

Wild fires turn millions of hectares of vegetation into charcoal each year. An international team of researchers led by Thorsten Dittgar from the Max Planck Institute for Marine Microbiology in Bremen and Rudolf Jaffé from Florida International University's Southeast Environmental Research Center in Miami has now shown that this charcoal does not remain in the soil, as previously thought. Instead, it is transported to the sea by rivers and thus enters the carbon cycle. The researchers analyzed water samples from all over the world. They demonstrated that soluble charcoal accounts for ten percent of the total amount of dissolved organic carbon.

 

 

http://www.mpg.de/7112434/charcoal_oceans

Edited April 19, 2013 by knocker

[knocker]

Exceptionally hot summers in Central and Eastern Europe (1951–2010)

Abstract

The paper focuses on exceptionally hot summers (EHS) as a manifestation of contemporary climate warming. The study identifies EHS occurrences in Central and Eastern Europe and describes the characteristic features of the region’s thermal conditions. Average air temperatures in June, July and August were considered, as well as the number of days with maximum temperatures exceeding 25, 30 and 35 Â°C, and with a minimum temperature greater than >20 Â°C, as recorded at 59 weather stations in 1951–2010. Extremely hot summers are defined as having an average temperature equal to or greater than the long-term average plus 2 SD. A calendar of EHSs was compiled and their spatial extent identified. The region experienced 12 EHSs, which occurred in a given year at 5 % or more stations (1972, 1981, 1988, 1992, 1997, 1998, 1999, 2002, 2003, 2006, 2007 and 2010). The EHS frequency of occurrence was found to be clearly on an increase. Indeed, only one EHS occurred during the first 30 years, but these occurred five times during the last 10 years of the study period. Their geographical extent varied both in terms of location and size. EHSs were observed at 57 out of the total of 59 weather stations in the study (the exceptions were Pecora and Cluj). The average air temperature of EHSs tended to exceed the relevant long-term average by 2–4 Â°C. The summer of 2010 was among the hottest (temperature anomaly 5.5–6 Â°C) and spatially largest.

 

http://link.springer.com/article/10.1007/s00704-012-0757-0/fulltext.html

Edited April 21, 2013 by knocker

[Gray-Wolf]

Hi Knocker! I think that the weaker the Jet gets the easier it is for inner continental highs to build and maintain and , in effect, dictate where any L.P. systems track further amplifying their impacts over the areas they masnifest?

 

I kinda hope that is this is what is ongoing then the scale of ice loss last year will allow the european high to push over us on occasion and allow a more 'gentle' summer than we've seen over the past 6 years?

 

We know that low solar will help with blocking high's so what happens when we enter the next solar min will be interesting? We can be assured of another cold winter but will we also inherit a summer drought?

 

Prior to our deluge summer half the country was in drought. Was the alterations to winter precipitation, at the hands of blocking highs, at play there? any continuation of the H.P. blocking into summer could become very serious for the SE over a period of months?

 

The sight of flooded homes is distressing enough but what of major water restrictions on homes and industry in the SE?

[knocker]

Detection of methane depletion associated with Stratospheric intrusion by Atmospheric Infrared Sounder (AIRS)^†

Abstract

[1] Atmospheric methane (CH₄) concentration in the mid-to-upper troposphere has been retrieved using atmospheric infrared sounder (AIRS) data on NASA EOS/AQUA. By selecting the AIRS strong CH₄ absorption channels near 1306 cm^-1, severe CH₄ depletion was mapped during a stratospheric intrusion event on March 27, 2010. The areas with depleted CH₄ mixing ratio are collocated with enhanced ozone (O₃) and low tropopause height. Aircraft measurements observed the depleted CH₄ and enhanced O₃ down to 550 hPa. An estimate of the depleted CH₄ amount resulted from stratospheric intrusion is -54 to -67 Tg yr^-1. This study suggests that the AIRS and/or other thermal infrared sounders can provide an observation of CH₄ variation associated with stratospheric intrusion, a key unknown in CH₄ budget, and this dataset will be also useful for studying the stratosphere-troposphere exchange (STE).

 

 

http://onlinelibrary.wiley.com/doi/10.1002/grl.50476/abstract

Edited April 21, 2013 by knocker

[knocker]

Continental-scale temperature variability during the past two millennia

Abstract  

Past global climate changes had strong regional expression. To elucidate their spatio-temporal pattern, we reconstructed past temperatures for seven continental-scale regions during the past one to two millennia. The most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century. At multi-decadal to centennial scales, temperature variability shows distinctly different regional patterns, with more similarity within each hemisphere than between them. There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century. The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions. Recent warming reversed the long-term cooling; during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years.

 

 

http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1797.html

 

A comment on the paper.

 

http://www.carbonbrief.org/blog/2013/04/scientists-reconstruct-2,000-year-temperature-history-continent-by-continent

Edited April 22, 2013 by knocker