Surface Temperature Datasets for the 21st Century 4.8.2010
The UK Met Office is leading a multi-institutional initiative on producing a new suite of surface temperature datasets to characterise changes at finer space and time scales. A workshop is planned in September 2010 in Exeter, UK, and several white papers have been solicited ahead for broad input thought a moderated blog. Read more.
State of the Climate in 2009 - NOAA Report 30.7.2010
This 20th annual report evaluates 10 key indicators of the Earth's climate including air and sea temperatures, sea level, sea-ice extension, ice and snow cover on land. The document has been published in BAMS (vol. 91), June 2010.
Regional Variability of Sea-Level change in the Indian Ocean 27.7.2010
The warming of the Indo-Pacific warm pool in the past 50 years seems the cause of an unevenly rising of Indian Ocean Sea levels affecting some densely populated costal areas. The study, published in Nature Geosciences, is co-authored by scientists from U. Colorado at Boulder and NCAR, among these authors is Dr G. Meehl, Co-chair of the WCRP WGCM.
Special JGR issue on Global Dimming and Brightening 20.7.2010
Recent evidence indicates that solar radiation at the Earth's surface is not stable over time, but undergoes significant decadal variations. The papers of this special issue of JGR discuss several aspects of global dimming and brightening including their representation in climate models and their impacts on the global climate system.
GRL article: Atmospheric aerosols and precipitation 16.7.2010
Aerosols affect precipitation in opposing ways. To find out the net effect, the scientists at GFDL, including WCRP JSC member V. Ramaswamy, simulated the response to increased black carbon levels. They found a small reduction in global mean precipitation. Read more.
WCRP effort to understand Low Cloud Feedback in Climate Models 12.7.2010
The WGCM Cloud Feedback Model Intercomparison Project (CFMIP) and the GEWEX Cloud System Study (GCSS) have initiated a joint project on the intercomparison of Large Eddy Models and Single Column Models (CGILS) to understand the physical mechanisms of low cloud feedback in climate models. Read more.
MJO dynamical forecast Intercomparison web resource 1.7.2010
NCEP has established an experimental operational MJO forecast intercomparison activity that was initiated by the US CLIVAR MJO working group. In 2010, the group was reformulated as the WCRP/WWRP THORPEX YOTC Task Force. For more information visit the website.
Sea-level Rise and its impacts on society 25.6.2010
The awaited book on Understanding Sea-Level Rise and Variability by J. Church, former WCRP/JSC Chair, P. Woodworth, former GLOSS Chair, T. Aarup, UNESCO/IOC, and W.S. Wilson, NOAA NESDIS, will be available in August 2010. The book provides a concise summary of past, present and future sea-level rise and its impacts on society. Download the order form.
Science special issue on Changing Oceans 22.6.2010
The science magazine publishes a series of review articles on the changes that are affecting the oceans. The articles provide an overview of recent discoveries as well as identify some of the challenges for preserving the oceans' resources. The editorial of the current Science issue features an introduction by John Church, former WCRP/JSC Chair.
WCRP Review article on global warming impacts on El Nino 27.5.2010
The WCRP/CLIVAR Panel on the Pacific Ocean concludes, in a review article published in Nature Geosciences, that the changes in the Pacific region due to the rising of global temperatures will affect the character of ENSO and the impacts that ENSO has on the Pacific countries. However, it remains hard to identify whether ENSO variability will be enhanced or moderated, or how the frequency of the events will change. Read the article.
Upper Ocean Warming 21.5.2010
A recent article in Science reports on a major international joint effort in comparing upper-ocean heat content datasets and identifying the sources of uncertainties attached to them. The study shows a robust evidence for a warming trend in the last decade. Read the article and news&views by K. Trenberth (GEWEX Chair).
Strong deep current in the Southern Ocean 11.5.2010
In a paper published in Nature Geoscience, Japanese and Australian scientists including Dr J. Church, former WCRP JSC Chair, show evidence of a deep ocean current with a volume equivalent to 40 Amazon Rivers. This is an important pathway in the global network of ocean currents that influence climate patterns. Read more.
2009 Highlights from Environmental Research Letters 6.5.2010
A collection of highlights from volume 4 of Environmental Research Lettersincludes contributions on sea-level rise, climate and energy, geoengineering. The collection will be free to read throughout 2010. ERL has also recently launched its latest focus issue, “Anticipated changes in the global atmospheric water cycle”.
Science article - Where has the energy from global warming gone? 30.4.2010
In a recent article in Science, Kevin Trenberth, former WOAP Chair and newly appointed GEWEX Chair, addresses the challenges of obtaining a closure of the Earth's energy budget. They suggest that state-of-the-art observations are unable to fully account for recent energy variability. Read more.
SPARC CCMVal Report now available 15.4.2010
The CCMVal activity of the WCRP SPARC project has just completed a comprehensive assessment of stratosphere-resolving chemistry-climate models, using process-oriented performance metrics. This assesssment is the result of the efforts of many scientists over the last two years, and has been extensively peer-reviewed. The final accepted version of the components of the report is now available to download.
CLIVAR Report: Earth System Initialization for Decadal Predictions 15.4.2010
In November 2009, an international group of 50 scientists gathered together to address some of the technical challenges that decadal prediction poses. The workshop, sponsored by WCRP/CLIVAR, was directed at making an inventory of initialization and perturbation techniques in earth system models and providing a roadmap to make skillful decadal predictions. Further information on the workshop outcomes can be found in the recently published report.
The Year of El Niño 07.4.2010
The ongoing El Niño event continues to have significant and widespread impacts. The signature of this event, which started in June 2009, is seen in basin-wide Pacific Ocean conditions, and in many of the climate patterns around the world that are typically impacted by an El Niño event. Read the WMO ENSO update.
GEWEX: Is There a Missing Low Cloud Feedback in Current Climate Models? 07.4.2010
An analysis by Prof. Graeme Stephen published in the last issue of GEWEX News suggests that solar radiation reflected by low clouds is significantly enhanced in models compared to real cloud observations. This finding has major implications for the cloud-climate feedback problem in model.
AMS Special Issues on Drought and Western Boundary Currents 18.3.2010
Two special collections of papers published in selected AMS peer-reviewed journals are drawn from research coordinated by WCRP/CLIVAR and US CLIVAR. The list of papers on Drought and the list on Western Boundary Currents can be access throught the AMS webpage
Science article: Decadal climate change caused by Stratospheric Water Vapor 10.3.2010
This study led by Susan Solomon, IPCC WG1 Co-chair for AR4, highlights the role of stratospheric water vapour concentrations in driving decadal variability in the global surface temperature. Read the article.
Article in Science: Hurricanes intensify Under Global Warming, Models Suggest 24.2.2010
A model study, led by US scientists (some of them members of the WCRP/CLIVAR panel) suggests that less, but more-distructive, hurricanes will cross the Atlantic Ocean in this century under greenhouse gas emissions as usual. Read the article.
Article on Nature Geoscience: IOD and ENSO Linkages 23.2.2010
The article, co-authored by members of the WCRP/CLIVAR Pacific and Indian Oceans Panels, suggests an influence of the State of the Indian Ocean Dipole on the following year's El Niño. Read the article.
BAMS article: A Unified Modeling Approach to Climate System Prediction 20.1.2010
In a recent BAMS article, J. Hurrell (WCRP CLIVAR SSG Co-chair) and colleagues discuss different strategies for a more unified approach to climate system prediction. At the heart of this new approach is the realization that all climate system predictions, regardless of time scale, share common processes and mechanisms; moreover, interactions across time and space scales are fundamental to the climate system itself. Read the article.
Article on Nature Reports Climate Change: More Knowledge, Less Certainty 26.1.2010
Kevin Trenberth, WOAP Chair, anticipates that the uncertainty in AR5's climate predictions and projections will be much greater than in previous IPCC reports, primarily because models will attempt new and better representations of important climate processes and their feedbacks . While our knowledge of certain factors does increase, so does our understanding of factors we previously did not account for or even recognize. This could present a major problem for public understanding of climate change. Read the article.
Article: Sea level budget from space gravimetry, satellite altimetry and Argo 12.1.2010
In an article published in the Global and Planetary Change, Anny Cazenave of the Laboratory for Studies in Space Geophysics and Oceanography (LEGOS) in Toulouse, France, and her colleagues quantified the contributions of melting land ice and thermal expansion to sea-level rise. They used gravity data from the GRACE satellites and temperature records collected by the Argo network of buoys. Read more.
Journal of Climate article: Application of MJO simulation diagnostics to climate models 4.1.2010
The ability of eight climate models to simulate the Madden–Julian oscillation (MJO) is examined using diagnostics developed by the U.S. Climate Variability and Predictability (CLIVAR) MJO Working Group. Read more.
Nature article: The Agulhas leakage contributing to the stability of the Atlantic Meridional Overturning Circulation (AMOC) 11.12.09
A new high-resolution ocean model study shows that the transport of warm, salty Indian Ocean water into the South Atlantic has increased during the past decades. The authors, who are members of the WCRP/CLIVAR Working Group on Ocean Development, suggest that the increase of the co-called Agulhas leakage is due to the southward shift of the westerly winds - probably anthropogenically influenced. This might have potential implications for the future evolution of the AMOC. Read the article. WCRP together with SCOR and IAPSO is co-sponsoring an ad hoc working group on the climatic Importance of the Greater Agulhas System.
BAMS article: Measuring Decadal prediction skills 8.12.09
A recent article published by G. Meehl, WGCM co-chair, and colleagues explores the factors that contribute to increasing predictive skills on decadal timescale. At least three factors influence time-evolving regional climate at the decadal time scale: 1) climate change commitment (further warming as the coupled climate system comes into adjustment with increases of greenhouse gases that have already occurred), 2) external forcing, particularly from future increases of greenhouse gases and recovery of the ozone hole, and 3) internally generated variability. Read the article.
GRL article: Evidence of long-term warming in the USA 19.11.09
A research team lead by Gerry Meehl, WGCM Co-chair, showed that the daily record high temperatures occurred twice as often as record lows over the last decade across the continental United States. By using computer simulation they predict that the US ratio of daily record high to record low temperatures would increase to about 20 to 1 by midcentury and 50 to 1 by 2100. The midcentury ratio could be much higher if emissions rose at an even greater pace, or it could be about 8 to 1 if emissions were reduced significantly, the model showed. This study will soon appear in Geophysical Research Letters. Read more.
SPARC and the Montreal Protocol 2.11.09
The recent published book "Twenty Years of Ozone Decline:Proceeding of the Symposium for the 20th Anniversary of the Montreal Protocol" features a chapter on SPARC Science supporting the Montreal Protocol by M. A. Geller and M.-L. Chanin. The chapter lists few examples of the SPARC contributions to the WMO/UNEP Ozone Assessments that provides the scientific bases for changes in the Montreal Protocol as well as its future role relating the same protocol. Download and read the chapter.
Tracking Changes in Earth's Global Energy: an Imperative for Adaptation 27.10.09
The first issue of Current Opinion in Environmental Sustainability features an article by Dr Kevin Trenberth, Chair of WCRP/WOAP, on the importance of tracking changes of energy within the Earth's climate system. The article tries to assess the current ability to track changes in reservoirs and flows of energy and argue that such ability is important for interpreting global and regional climate change, and prospect for the future. Read more.
GRL article: Indian Ocean Dipole preconditioning Australia bush fires 23.10.09
A shift in the Indian Ocean pattern can be the cause of the bush fires that swept across southeastern Australia in February, killing more than 170 people. Wenju Cai (Chair of WCRP/CLIVAR Pacific Ocean Panel) and his colleagues showed a link between the Indian Ocean sea-surface temperature anomaly and the severe drought in southeastern Australia in a recent paper published in Geophysical Research Letter. Read the article.
Special Collection J. Climate: US CLIVAR Drought Initiative 12.10.09
This special collection focuses on the physical mechanisms that produce drought, in particular multi-season, multi-year droughts, and in a broader sense provides a coordinated assessment of our current modeling capabilities and understanding of hydroclimatic variabiliy throughout the world. Several articles are expected to appear in J. Climate over the next
several months. The first of these are now downloadable from AMS Journals Online.
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