WorldWideScience

Sample records for monsoon climate research

  1. The Joint Aerosol-Monsoon Experiment: A New Challenge to Monsoon Climate Research

    Science.gov (United States)

    Lau, William K. M.

    2008-01-01

    Aerosol and monsoon related droughts and floods are two of the most serious environmental hazards confronting more than 60% of the population of the world living in the Asian monsoon countries. In recent years, thanks to improved satellite and in-situ observations, and better models, great strides have been made in aerosol, and monsoon research respectively. There is now a growing body of evidence suggesting that interaction of aerosol forcing with water cycle dynamics in monsoon regions may substantially alter the redistribution of energy at the earth surface and in the atmosphere, and therefore significantly impact monsoon rainfall variability and long term trends. In this talk, I will describe issues related to societal needs, scientific background, and challenges in studies of aerosol-water cycle interaction in Asian monsoon regions. As a first step towards addressing these issues, the authors call for an integrated observation and modeling research approach aimed at the interactions between aerosol chemistry and radiative effects and monsoon dynamics of the coupled ocean-atmosphere-land system. A Joint Aerosol-Monsoon Experiment (JAMEX) is proposed for 2007-2011, with an enhanced observation period during 2008-09, encompassing diverse arrays of observations from surface, aircraft, unmanned aerial vehicles, and satellites of physical and chemical properties of aerosols, long range aerosol transport as well as meteorological and oceanographic parameters in the Indo-Pacific Asian monsoon region. JAMEX will leverage on coordination among many ongoing and planned national programs on aerosols and monsoon research in China, India, Japan, Nepal, Italy, US, as well as international research programs of the World Climate Research Program (WCRP) and the World Meteorological Organization (WMO).

  2. Bay of Bengal Monsoon Experiment (BOBMEX) — A component of the Indian Climate Research Programme (ICRP)

    Indian Academy of Sciences (India)

    D R Sikka; P Sanjeeva Rao

    2000-06-01

    The Indian Climate Research Programme (ICRP) focuses on the study of climate variability and its impact on agriculture. To address the role of the Bay of Bengal in monsoon variability, a process study was organised during July-August 1999, deploying research ships, buoys, INSAT, coastal radar and conventional observational systems to collect information about the coupled ocean-atmosphere system over the warm waters of the Bay of Bengal. The paper gives the background of the ICRP and the organisation and implementation of the Bay of Bengal Monsoon Experiment (BOBMEX) in its field phase.

  3. Thrusts and Prospects on Understanding and Predicting Asian Monsoon Climate

    Institute of Scientific and Technical Information of China (English)

    WANG Bin

    2008-01-01

    Development of monsoon climate prediction through integrated research efforts to improve our understanding of monsoon variability and predictability is a primary goal of the Asian Monsoon Years (2007-2011) and International Monsoon Study under the leadership of the World Climate Research Programme.The present paper reviews recent progress in Asian monsoon research focusing on (1) understanding and modeling of the monsoon variability, (2) determining the sources and limits of predictability, and (3) assessing the current status of climate prediction, with emphasis on the weekly to interannual time scales. Particular attention is paid to identify scientific issues and thrust areas, as well as potential directions to move forward in an attempt to stimulate future research to advance our understanding of monsoon climate dynamics and improve our capability to forecast Asian monsoon climate variation.

  4. Aerosol and monsoon climate interactions over Asia

    Science.gov (United States)

    Li, Zhanqing; Lau, W. K.-M.; Ramanathan, V.; Wu, G.; Ding, Y.; Manoj, M. G.; Liu, J.; Qian, Y.; Li, J.; Zhou, T.; Fan, J.; Rosenfeld, D.; Ming, Y.; Wang, Y.; Huang, J.; Wang, B.; Xu, X.; Lee, S.-S.; Cribb, M.; Zhang, F.; Yang, X.; Zhao, C.; Takemura, T.; Wang, K.; Xia, X.; Yin, Y.; Zhang, H.; Guo, J.; Zhai, P. M.; Sugimoto, N.; Babu, S. S.; Brasseur, G. P.

    2016-12-01

    The increasing severity of droughts/floods and worsening air quality from increasing aerosols in Asia monsoon regions are the two gravest threats facing over 60% of the world population living in Asian monsoon regions. These dual threats have fueled a large body of research in the last decade on the roles of aerosols in impacting Asian monsoon weather and climate. This paper provides a comprehensive review of studies on Asian aerosols, monsoons, and their interactions. The Asian monsoon region is a primary source of emissions of diverse species of aerosols from both anthropogenic and natural origins. The distributions of aerosol loading are strongly influenced by distinct weather and climatic regimes, which are, in turn, modulated by aerosol effects. On a continental scale, aerosols reduce surface insolation and weaken the land-ocean thermal contrast, thus inhibiting the development of monsoons. Locally, aerosol radiative effects alter the thermodynamic stability and convective potential of the lower atmosphere leading to reduced temperatures, increased atmospheric stability, and weakened wind and atmospheric circulations. The atmospheric thermodynamic state, which determines the formation of clouds, convection, and precipitation, may also be altered by aerosols serving as cloud condensation nuclei or ice nuclei. Absorbing aerosols such as black carbon and desert dust in Asian monsoon regions may also induce dynamical feedback processes, leading to a strengthening of the early monsoon and affecting the subsequent evolution of the monsoon. Many mechanisms have been put forth regarding how aerosols modulate the amplitude, frequency, intensity, and phase of different monsoon climate variables. A wide range of theoretical, observational, and modeling findings on the Asian monsoon, aerosols, and their interactions are synthesized. A new paradigm is proposed on investigating aerosol-monsoon interactions, in which natural aerosols such as desert dust, black carbon from

  5. Aerosol and monsoon climate interactions over Asia: AEROSOL AND MONSOON CLIMATE INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhanqing [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Lau, W. K. -M. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Ramanathan, V. [Department of Atmospheric and Climate Sciences, University of California, San Diego California USA; Wu, G. [Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing China; Ding, Y. [National Climate Center, China Meteorological Administration, Beijing China; Manoj, M. G. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Liu, J. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Qian, Y. [Pacific Northwest National Laboratory, Richland Washington USA; Li, J. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Zhou, T. [Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing China; Fan, J. [Pacific Northwest National Laboratory, Richland Washington USA; Rosenfeld, D. [Institute of Earth Sciences, Hebrew University, Jerusalem Israel; Ming, Y. [Geophysical Fluid Dynamic Laboratory, NOAA, Princeton New Jersey USA; Wang, Y. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena California USA; Huang, J. [College of Atmospheric Sciences, Lanzhou University, Lanzhou China; Wang, B. [Department of Atmospheric Sciences, University of Hawaii, Honolulu Hawaii USA; School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing China; Xu, X. [Chinese Academy of Meteorological Sciences, Beijing China; Lee, S. -S. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Cribb, M. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Zhang, F. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Yang, X. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Zhao, C. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Takemura, T. [Research Institute for Applied Mechanics, Kyushu University, Fukuoka Japan; Wang, K. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Xia, X. [Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing China; Yin, Y. [School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing China; Zhang, H. [National Climate Center, China Meteorological Administration, Beijing China; Guo, J. [Chinese Academy of Meteorological Sciences, Beijing China; Zhai, P. M. [Chinese Academy of Meteorological Sciences, Beijing China; Sugimoto, N. [National Institute for Environmental Studies, Tsukuba Japan; Babu, S. S. [Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram India; Brasseur, G. P. [Max Planck Institute for Meteorology, Hamburg Germany

    2016-11-15

    Asian monsoons and aerosols have been studied extensively which are intertwined in influencing the climate of Asia. This paper provides a comprehensive review of ample studies on Asian aerosol, monsoon and their interactions. The region is the primary source of aerosol emissions of varies species, influenced by distinct weather and climatic regimes. On continental scale, aerosols reduce surface insolation and weaken the land-ocean thermal contrast, thus inhibiting the development of monsoons. Locally, aerosol radiative effects alter the thermodynamic stability and convective potential of the lower atmosphere leading to reduced temperatures, increased atmospheric stability, and weakened wind and atmospheric circulation. The atmospheric thermodynamic state may also be altered by the aerosol serving as cloud condensation nuclei or ice nuclei. Many mechanisms have been put forth regarding how aerosols modulate the amplitude, frequency, intensity, and phase of numerous monsoon climate variables. A wide range of theoretical, observational, and modeling findings on the Asian monsoon, aerosols, and their interactions are synthesized. A new paradigm is proposed on investigating aerosol-monsoon interactions, in which natural aerosols such as desert dust, black carbon from biomass burning, and biogenic aerosols from vegetation are considered integral components of an intrinsic aerosol-monsoon climate system, subject to external forcings of global warming, anthropogenic aerosols, and land use and change. Future research on aerosol-monsoon interactions calls for an integrated approach and international collaborations based on long-term sustained observations, process measurements, and improved models, as well as using observations to constrain model simulations and projections.

  6. Aerosol-Water Cycle Interaction: A New Challenge in Monsoon Climate Research

    Science.gov (United States)

    Lau, William K. M.

    2006-01-01

    Long recognized as a major environmental hazard, aerosol is now known to have strong impacts on both regional and global climate. It has been estimated that aerosol may reduce by up to 10% of the seasonal mean solar radiation reaching the earth surface, producing a global cooling effect that opposes global warming (Climate Change 2001). This means that the potential perils that humans have committed to global warming may be far greater than what we can detect at the present. As a key component of the Earth climate system, the water cycle is profoundly affected by the presence of aerosols in the atmosphere. Through the so-called "direct effect", aerosol scatters and/or absorbs solar radiation, thus cooling the earth surface and changing the horizontal and vertical radiational heating contrast in the atmosphere. The heating contrast drives anomalous atmospheric circulation, resulting in changes in convection, clouds, and rainfall. Another way aerosol can affect the water cycle is through the so-called "indirect effects", whereby aerosol increases the number of cloud condensation nuclei, prolongs life time of clouds, and inhibits the growth of cloud drops to raindrops. This leads to more clouds, and increased reflection of solar radiation, and further cooling at the earth surface. In monsoon regions, the response of the water cycle to aerosol forcing is especially complex, not only because of presence of diverse mix of aerosol species with vastly different radiative properties, but also because the monsoon is strongly influenced by ocean and land surface processes, land use, land change, as well as regional and global greenhouse warming effects. Thus, sorting out the impacts of aerosol forcing, and interaction with the monsoon water cycle is a very challenging problem. In this talk, I will offer some insights into how aerosols may impact the Asian monsoon based on preliminary results from satellite observations and climate model experiments. Specifically, I will

  7. The First Pan-WCRP Workshop on Monsoon Climate Systems: Toward Better Prediction of the Monsoons

    Energy Technology Data Exchange (ETDEWEB)

    Sperber, K R; Yasunari, T

    2005-07-27

    In 2004 the Joint Scientific Committee (JSC) that provides scientific guidance to the World Climate Research Programme (WCRP) requested an assessment of (1) WCRP monsoon related activities and (2) the range of available observations and analyses in monsoon regions. The purpose of the assessment was to (a) define the essential elements of a pan-WCRP monsoon modeling strategy, (b) identify the procedures for producing this strategy, and (c) promote improvements in monsoon observations and analyses with a view toward their adequacy, and addressing any undue redundancy or duplication. As such, the WCRP sponsored the ''1st Pan-WCRP Workshop on Monsoon Climate Systems: Toward Better Prediction of the Monsoons'' at the University of California, Irvine, CA, USA from 15-17 June 2005. Experts from the two WCRP programs directly relevant to monsoon studies, the Climate Variability and Predictability Programme (CLIVAR) and the Global Energy and Water Cycle Experiment (GEWEX), gathered to assess the current understanding of the fundamental physical processes governing monsoon variability and to highlight outstanding problems in simulating the monsoon that can be tackled through enhanced cooperation between CLIVAR and GEWEX. The agenda with links to the presentations can be found at: http://www.clivar.org/organization/aamon/WCRPmonsoonWS/agenda.htm. Scientific motivation for a joint CLIVAR-GEWEX approach to investigating monsoons includes the potential for improved medium-range to seasonal prediction through better simulation of intraseasonal (30-60 day) oscillations (ISO's). ISO's are important for the onset of monsoons, as well as the development of active and break periods of rainfall during the monsoon season. Foreknowledge of the active and break phases of the monsoon is important for crop selection, the determination of planting times and mitigation of potential flooding and short-term drought. With a few exceptions simulations of ISO are

  8. The Aerosol-Monsoon Climate System of Asia

    Science.gov (United States)

    Lau, William K. M.; Kyu-Myong, Kim

    2012-01-01

    In Asian monsoon countries such as China and India, human health and safety problems caused by air-pollution are worsening due to the increased loading of atmospheric pollutants stemming from rising energy demand associated with the rapid pace of industrialization and modernization. Meanwhile, uneven distribution of monsoon rain associated with flash flood or prolonged drought, has caused major loss of human lives, and damages in crop and properties with devastating societal impacts on Asian countries. Historically, air-pollution and monsoon research are treated as separate problems. However a growing number of recent studies have suggested that the two problems may be intrinsically intertwined and need to be studied jointly. Because of complexity of the dynamics of the monsoon systems, aerosol impacts on monsoons and vice versa must be studied and understood in the context of aerosol forcing in relationship to changes in fundamental driving forces of the monsoon climate system (e.g. sea surface temperature, land-sea contrast etc.) on time scales from intraseasonal variability (weeks) to climate change ( multi-decades). Indeed, because of the large contributions of aerosols to the global and regional energy balance of the atmosphere and earth surface, and possible effects of the microphysics of clouds and precipitation, a better understanding of the response to climate change in Asian monsoon regions requires that aerosols be considered as an integral component of a fully coupled aerosol-monsoon system on all time scales. In this paper, using observations and results from climate modeling, we will discuss the coherent variability of the coupled aerosol-monsoon climate system in South Asia and East Asia, including aerosol distribution and types, with respect to rainfall, moisture, winds, land-sea thermal contrast, heat sources and sink distributions in the atmosphere in seasonal, interannual to climate change time scales. We will show examples of how elevated

  9. Dynamics of Projected Changes in South Asian Summer Monsoon Climate

    Science.gov (United States)

    Kulkarni, A.; Sabade, S.; Kripalani, R.

    2011-12-01

    South Asian summer monsoon (June through September) rainfall simulation and its potential future changes are evaluated in a multi-model ensemble of global coupled climate models outputs under World Climate Research Program Coupled Model Intercomparison Project (WCRP CMIP3) data set. The response of South Asian summer monsoon to a transient increase in future anthropogenic radiative forcing is investigated for two time slices , middle (2031-2050) and end of the 21st century (2081-2100) in the non-mitigated Special Report on Emission Scenarios (SRES) B1, A1B and A2 .There is large inter-model variability in simulation of spatial characteristics of seasonal monsoon precipitation. Ten out of 25 models are able to simulate space-time characteristics of South Asian monsoon precipitation reasonably well. The response of these selected 10 models have been examined for projected changes in seasonal monsoon rainfall. The multi-model ensemble of these 10 models project significant increase in monsoon precipitation with global warming. The substantial increase in precipitation is observed over western equatorial Indian Ocean and southern parts of India. However the monsoon circulation weakens significantly under all the three climate change experiments. Possible mechanisms for projected increase in precipitation and for precipitation-wind paradox have been discussed. The surface temperature over Asian landmass increases in pre-monsoon months due to global warming and heat low over north-west India intensifies. The dipole snow configuration over Eurasian continent strengthens in warmer atmosphere which is conducive for enhancement in precipitation over Indian landmass. The increase in precipitation is mainly contributed by the substantial increase in water vapor content in the atmosphere. No notable changes have been projected in the El Nino-Monsoon relationship.

  10. East Asian monsoon climate simulated in the PlioMIP

    Directory of Open Access Journals (Sweden)

    R. Zhang

    2013-02-01

    Full Text Available Based on the simulations with fifteen climate models in the Pliocene Model Intercomparison Project (PlioMIP, the regional climate of East Asia (focusing on China during the mid-Pliocene is investigated in this study. Compared to the pre-industrial, the multi-model ensemble mean (MMM of all models shows the East Asian summer wind (EASW largely strengthens in monsoon China, and the East Asian winter wind (EAWW strengthens in south monsoon China but slightly weakens in north monsoon China in mid-Pliocene. The MMM of all models also illustrates a warmer and wetter mid-Pliocene climate in China. The simulated weakened mid-Pliocene EAWW in north monsoon China and intensified EASW in monsoon China agree well with geological reconstructions. However, the model-model discrepancy in simulating mid-Pliocene East Asian monsoon climate, in particular EAWW, should be further addressed in the future work of PlioMIP.

  11. Book Review: Late Cenozoic Climate Change in Asia: Loess, Monsoon and Monsoon-arid Environment Evolution

    Science.gov (United States)

    Clemens, Steven C.

    2015-01-01

    Loess-Paleosol deposits drape >500,000 km2 of eastern China, spanning environments from the humid, monsoon-influenced regions near the coast to the arid, westerlies-dominated regions inland. Sections, up to hundreds of meters thick, are exposed in deeply incised river valleys and can be accessed as well by drilling. Combined, the high sedimentation rates and extensive geographic coverage make these sections unique among global terrestrial sediment archives. The Chinese loess-paleosol sequences, and the arid interior regions to the northwest, record diverse aspects of geologic and environmental change ranging from the tectonic evolution of the Tibetan Plateau (106 year time scale) through glacial-interglacial scale changes in global ice volume and greenhouse gasses (105 year time scale) on down through the orbital (104 years) to millennial and centennial scale events (103-102 year) relevant to the underpinnings of human interactions with changing environmental pressures. 'Late Cenozoic Climate Chang in Asia: Loess, Monsoon and Monsoon-arid Environment Evolution' is a timely contribution that synthesizes findings derived from the extensive work in these areas, places the findings in the broader context of global climate change and helps to define avenues for future research.

  12. Examining Impact of Global warming on the summer monsoon system using regional Climate Model (PRECIS)

    Science.gov (United States)

    Patwardhan, S. K.; Kundeti, K.; Krishna Kumar, K.

    2011-12-01

    Every year, southwest monsoon arrives over Indian region with remarkable regularity. It hits the southern state of Kerala first by the end of May or the early June. More than 70% of the annual precipitation is received during the four monsoon months viz. June to September. This monsoon rainfall is vital for the agriculture as well as for the yearly needs of Indian population. The performance of the monsoon depends on the timely onset over southern tip of India and its progress along the entire country. This northward progression of monsoon to cover the entire Indian landmass, many times, is associated with the formation of synoptic scale system in the Bay of Bengal region and their movement along the monsoon trough region. The analysis of the observed cyclonic disturbances show that their frequency has reduced in recent decades. It is, therefore, necessary to assess the effect of global warming on the monsoon climate of India. A state-of-art regional climate modelling system, known as PRECIS (Providing REgional Climates for Impacts Studies) developed by the Hadley Centre for Climate Prediction and Research, U.K. is applied over the South Asian domain to investigate the impact of global warming on the cyclonic disturbances. The PRECIS simulations at 50 km x 50 km horizontal resolution are made for two time slices, present (1961-1990) and the future (2071-2100), for two socio-economic scenarios A2 and B2. The model skills are evaluated using observed precipitation and surface air temperature. The model has shown reasonably good skill in simulating seasonal monsoon rainfall, whereas cold bias is seen in surface air temperature especially in post-monsoon months. The typical monsoon features like monsoon trough, precipitation maxima over west coast and northeast India are well simulated by the model. The model simulations under the scenarios of increasing greenhouse gas concentrations and sulphate aerosols are analysed to study the likely changes in the quasi

  13. Interconnections between the Asian monsoon, ENSO, and high northern latitude climate during the Holocene

    Institute of Scientific and Technical Information of China (English)

    HONG Bing; LIN Qinghua; HONG Yetang

    2006-01-01

    The article emphatically reviews the research progress in interconnections between the East Asian and Indian Ocean summer monsoons, between the Asian monsoon and the El Nino-Southern Oscillation (ENSO) activity, and between the monsoon, ENSO and the changing of the North Atlantic climate during the Holocene. According to the studies of recent years, it is found that the intensity variations of the East Asian and Indian Ocean summer monsoons show an opposite relationship, which may be closely related to the phenomena of ENSO in the equatorial Pacific Ocean and the variation of the deep-water formation of the North Atlantic Ocean on the interannual to orbital time scales. The 4k and 8k events occurring at around 4200 and 8200 a BP, respectively, might be the two in a series of severe paleo-El Nino events during the Holocene, strongly reflecting the interactions and influences of the monsoons, ENSO and the North Atlantic climate. In order to better understand the relationships between these paleoclimatic phenomena, scientists need to strengthen the research work on the Asian monsoon division and the comparison between monsoon proxy records, and the study on the proxy record of sea surface temperature with high time-resolution in the equatorial Pacific Ocean and the simulation research of paleoclimate condition.

  14. History and variability of East Asian monsoon climate since the late Miocene

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ The variability and dynamic mechanism of the East Asian monsoon climate is a major scientific puzzle in the exploration of global change.As early as in the late 1990s,a research team led by Prof.AN Zhisheng from the CAS Institute of Earth Environment started their work in this topic,with an objective of improving the hypothesis of monsoon-controlled East Asian environment and advancing the basic studies of past global changes in eastern Asia.

  15. The once and future pulse of Indian monsoonal climate

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, K.K.; Patwardhan, S.K.; Goswami, B.N. [Indian Institute of Tropical Meteorology, Pune (India); Kamala, K. [Universiti Pierre et Marie Curie, LOCEAN-IPSL, Paris (France); Rajagopalan, Balaji [University of Colorado, Boulder, CO (United States); Hoerling, Martin P.; Eischeid, Jon K. [NOAA/ESRL/PSD, Boulder, CO (United States); Srinivasan, G. [RIMES, Pathunthani (Thailand); Nemani, Ramakrishna [NASA-Ames Research Center, Moffett Field, CA (United States)

    2011-06-15

    We present a comprehensive assessment of the present and expected future pulse of the Indian monsoon climate based on observational and global climate model projections. The analysis supports the view that seasonal Indian monsoon rains in the latter half of the 21th century may not be materially different in abundance to that experienced today although their intensity and duration of wet and dry spells may change appreciably. Such an assessment comes with considerable uncertainty. With regard to temperature, however, we find that the Indian temperatures during the late 21st Century will very likely exceed the highest values experienced in the 130-year instrumental record of Indian data. This assessment comes with higher confidence than for rainfall because of the large spatial scale driving the thermal response of climate to greenhouse gas forcing. We also find that monsoon climate changes, especially temperature, could heighten human and crop mortality posing a socio-economic threat to the Indian subcontinent. (orig.)

  16. Effect of climate change on seasonal monsoon in Asia and its impact on the variability of monsoon rainfall in Southeast Asia

    Directory of Open Access Journals (Sweden)

    Yen Yi Loo

    2015-11-01

    Full Text Available Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment. Although there are enough historical evidence to support the theory that climate change is a natural phenomenon, many research scientists are widely in agreement that the increase in temperature in the 20th century is anthropologically related. The associated effects are the variability of rainfall and cyclonic patterns that are being observed globally. In Southeast Asia the link between global warming and the seasonal atmospheric flow during the monsoon seasons shows varying degree of fuzziness. This study investigates the impact of climate change on the seasonality of monsoon Asia and its effect on the variability of monsoon rainfall in Southeast Asia. The comparison of decadal variation of precipitation and temperature anomalies before the 1970s found general increases which were mostly varying. But beyond the 1970s, global precipitation anomalous showed increases that almost corresponded with increases in global temperature anomalies for the same period. There are frequent changes and a shift westward of the Indian summer monsoon. Although precipitation is observed to be 70% below normal levels, in some areas the topography affects the intensity of rainfall. These shifting phenomenon of other monsoon season in the region are impacting on the variability of rainfall and the onset of monsoons in Southeast Asia and is predicted to delay for 15 days the onset of the monsoon in the future. The variability of monsoon rainfall in the SEA region is observed to be decadal and the frequency and intensity of intermittent flooding of some areas during the monsoon season have serious consequences on the human, financial, infrastructure and food security of the region.

  17. Effect of climate change on seasonal monsoon in Asia and its impact on the variability of monsoon rainfall in Southeast Asia

    Institute of Scientific and Technical Information of China (English)

    Yen Yi Loo; Lawal Billa; Ajit Singh

    2015-01-01

    Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment. Although there are enough historical evidence to support the theory that climate change is a natural phenomenon, many research scientists are widely in agreement that the increase in temperature in the 20th century is anthropologically related. The associated effects are the variability of rainfall and cyclonic patterns that are being observed globally. In Southeast Asia the link between global warming and the seasonal atmospheric flow during the monsoon seasons shows varying degree of fuzziness. This study investigates the impact of climate change on the seasonality of monsoon Asia and its effect on the variability of monsoon rainfall in Southeast Asia. The comparison of decadal variation of precipitation and temperature anomalies before the 1970s found general increases which were mostly varying. But beyond the 1970s, global precipitation anomalous showed increases that almost corresponded with increases in global temperature anomalies for the same period. There are frequent changes and a shift westward of the Indian summer monsoon. Although precipitation is observed to be 70%below normal levels, in some areas the topography affects the intensity of rainfall. These shifting phenomenon of other monsoon season in the region are impacting on the variability of rainfall and the onset of monsoons in Southeast Asia and is predicted to delay for 15 days the onset of the monsoon in the future. The variability of monsoon rainfall in the SEA region is observed to be decadal and the frequency and intensity of intermittent flooding of some areas during the monsoon season have serious consequences on the human, financial, infrastructure and food security of the region.

  18. Future projection of mean and variability of the Asian Summer Monsoon and Indian Ocean Climate systems

    Energy Technology Data Exchange (ETDEWEB)

    Annamalai, H [IPRC, University of Hawaii

    2014-09-15

    The overall goal of this project is to assess the ability of the CMIP3/5 models to simulate the Indian-Ocean monsoon systems. The PI along with post-docs investigated research issues ranging from synoptic systems to long-term trends over the Asian monsoon region. The PI applied diagnostic tools such as moist static energy (MSE) to isolate: the moist and radiative processes responsible for extended monsoon breaks over South Asia, precursors in the ENSO-monsoon association, reasons for the drying tendency over South Asia and the possible effect on tropical Indian Ocean climate anomalies influencing certain aspects of ENSO characteristics. By diagnosing various observations and coupled model simulations, we developed working hypothesis and tested them by carrying out sensitivity experiments with both linear and nonlinear models. Possible physical and dynamical reasons for model sensitivities were deduced. On the teleconnection front, the ability of CMIP5 models in representing the monsoon-desert mechanism was examined recently. Further more, we have applied a suite of diagnostics and have performed an in depth analysis on CMIP5 integrations to isolate the possible reasons for the ENSO-monsoon linkage or lack thereof. The PI has collaborated with Dr. K.R. Sperber of PCMDI and other CLIVAR Asian-Australian monsoon panel members in understanding the ability of CMIP3/5 models in capturing monsoon and its spectrum of variability. The objective and process-based diagnostics aided in selecting models that best represent the present-day monsoon and its variability that are then employed for future projections. Two major highlights were an invitation to write a review on present understanding monsoons in a changing climate in Nature Climate Change, and identification of an east-west shift in observed monsoon rainfall (more rainfall over tropical western Pacific and drying tendency over South Asia) in the last six decades and attributing that shift to SST rise over the tropical

  19. Applications of monsoon research: Opportunities to inform decisionmaking and reduce regional vulnerability

    Science.gov (United States)

    Ray, A. J.; Garfin, G. M.; Wilder, M.; Lenart, M.; Vásquez-León, M.; Comrie, A. C.

    2007-05-01

    This presentation will describe ongoing efforts to understand interactions between the North American Monsoon and society, in order to develop applications for monsoon research in a highly complex, multicultural and binational region. The North American Monsoon is an annual precipitation regime that begins in early June in Mexico and progresses northward to the southwestern United States. The region includes stakeholders in large urban complexes, productive agricultural areas, and sparsely populated arid and semi-arid ecosystems. The political, cultural, and socioeconomic divisions between the U.S. and Mexico create a broad range of sensitivities to climate variability as well as capacities to use forecasts and other information to cope with climate. We will highlight methodologies to link climate science with society and analyze opportunities for monsoon science to benefit society in four sectors: natural hazards management, agriculture, public health, and water management. We present a synthesized list of stakeholder needs and a calendar of decisions to help scientists link user needs to potential forecasts and products. To ensure usability of forecasts and other research products, we recommend iterative scientist-stakeholder interactions, through integrated assessments. These knowledge- exchange interactions can improve the capacity for stakeholders to use forecasts thoughtfully and inform the development of research, and for the research community to obtain feedback on climate-related products and receive insights to guide research direction. We expect that integrated assessments can capitalize on the opportunities for monsoon science to inform decisionmaking, in the best instances, reduce regional climate vulnerabilities and enhance regional sustainability

  20. Evidence for signiifcant climate impacts in monsoonal Asia at 8.2 ka from multiple proxies and model simulations

    Institute of Scientific and Technical Information of China (English)

    MORRILL Carrie; WAGNER Amy J; OTTO-BLIESNER Bette L; ROSENBLOOM Nan

    2011-01-01

    Given the likelihood of future reductions in the strength of the Atlantic Meridional Overturning Circulation (AMOC), it is important to document how changes in the AMOC have altered climate patterns in the past and to assess the skill of coupled climate models in reproducing these teleconnections. Of past abrupt changes in the AMOC, the 8.2 ka event provides a particularly useful case study because its duration, magnitude of AMOC reduction and background climate state are closest to conditions expected in the future. In this research, we present an expanded proxy synthesis of the 8.2 ka event in monsoonal Asia, including new high-resolution lake and bog records, more sites from the East Asia monsoon region and proxies of winter monsoon strength. We compare proxy evidence with a new simulation of the 8.2 ka event using the Community Climate System Model version 3 (CCSM3) and prescribing North Atlantic freshwater forcing according to the latest reconstructions. We ifnd clear and objectively-determined evidence for 8.2 ka climate anomalies at nearly all of the fourteen proxy sites, emphasizing the strong and widespread impacts of the event in monsoonal Asia during both summer and winter seasons. The model simulation corroborates that these anomalies, described generally as a weakening of the summer monsoon and strengthening of the winter monsoon, were likely caused by a reduction of the AMOC. Examination of regional anomalies in East Asia reveals some spatial heterogeneity, however, that in the model simulation is caused by contraction of the seasonal migration of the subtropical monsoon front. The duration of climate anomalies at 8.2 ka in monsoonal Asia, both in proxy records and the model simulation, generally matches the duration of the event in Greenland ice core δ18O, further supporting a tight connection to the North Atlantic.

  1. Impact of Climate Change on the Characteristics of Indian Summer Monsoon Onset

    Directory of Open Access Journals (Sweden)

    Savita Patwardhan

    2014-01-01

    Full Text Available A high resolution regional climate modeling system, known as PRECIS (Providing REgional Climate for Impact Studies, developed by Hadley Centre for Climate Prediction and Research, UK, is applied for Indian subcontinent to assess the impact of climate change on the summer monsoon onset characteristics. The present day simulation (1961–1990 with PRECIS is evaluated for the characteristics of onset over Kerala, southernmost part of India, where the monsoon sets in over Indian landmass. The meteorological parameters like precipitation, outgoing long wave radiation (OLR, and low level winds are analysed to study the monsoon onset over Kerala. The model is able to capture the sudden and sharp increase of rainfall associated with the onset. The rapid built-up of convective activity over the southeastern Arabian Sea and Bay of Bengal is well represented by the model. PRECIS simulations, under scenarios of increasing greenhouse gas concentrations and sulphate aerosols, are analysed to study the likely changes in the onset characteristics in future, towards the end of present century (2071–2100. The analysis does not indicate significant difference in the mean onset dates in A2 and B2 scenarios. However, the variability of onset date is likely to be more towards the end of the 21st century especially in A2 scenario.

  2. Asian Monsoon Variability from the Monsoon Asia Drought Atlas (MADA) and Links to Indo-Pacific Climate

    Science.gov (United States)

    Ummenhofer, Caroline; D'Arrigo, Rosanne; Anchukaitis, Kevin; Hernandez, Manuel; Buckley, Brendan; Cook, Edward

    2014-05-01

    Drought patterns across monsoon and temperate Asia over the period 1877-2005 are linked to Indo-Pacific climate variability associated with the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). Using the Monsoon Asia Drought Atlas (MADA) composed of a high-resolution network of hydroclimatically sensitive tree-ring records with a focus on the June-August months, spatial drought patterns during El Niño and IOD events are assessed as to their agreement with an instrumental drought index and consistency in the drought response amongst ENSO/IOD events. Spatial characteristics in drought patterns are related to regional climate anomalies over the Indo-Pacific basin, using reanalysis products, including changes in the Asian monsoon systems, zonal Walker circulation, moisture fluxes, and precipitation. A weakening of the monsoon circulation over the Indian subcontinent and Southeast Asia during El Niño events, along with anomalous subsidence over monsoon Asia and reduced moisture flux, is reflected in anomalous drought conditions over India, Southeast Asia and Indonesia. When an IOD event co-occurs with an El Niño, severe drought conditions identified in the MADA for Southeast Asia, Indonesia, eastern China and central Asia are associated with a weakened South Asian monsoon, reduced moisture flux over China, and anomalous divergent flow and subsidence over Indonesia. Variations in the strength of the South Asian monsoon can also be linked to the Strange Parallels Drought (1756-1768) affecting much of Southeast Asia and the Indian subcontinent in the mid-18th Century. Large-scale climate anomalies across the wider region during years with an anomalously strengthened/weakened South Asian monsoon are discussed with implications for severe droughts prior to the instrumental period. Insights into the relative influences of Pacific and Indian Ocean variability for Asian monsoon climate on interannual to decadal and longer timescales, as recorded in the

  3. Workshop on Monsoon Climate Systems: Toward Better Prediction of the Monsoon

    Energy Technology Data Exchange (ETDEWEB)

    Sperber, K R; Yasunari, T

    2005-12-20

    The Earth's monsoon systems are the life-blood of more than two-thirds of the world's population through the rainfall they provide to the mainly agrarian societies they influence. More than 60 experts gathered to assess the current understanding of monsoon variability and to highlight outstanding problems simulating the monsoon.

  4. The effects of monsoons and climate teleconnections on the Niangziguan Karst Spring discharge in North China

    Science.gov (United States)

    Zhang, Juan; Hao, Yonghong; Hu, Bill X.; Huo, Xueli; Hao, Pengmei; Liu, Zhongfang

    2017-01-01

    Karst aquifers supply drinking water for 25 % of the world's population, and they are, however, vulnerable to climate change. This study is aimed to investigate the effects of various monsoons and teleconnection patterns on Niangziguan Karst Spring (NKS) discharge in North China for sustainable exploration of the karst groundwater resources. The monsoons studied include the Indian Summer Monsoon, the West North Pacific Monsoon and the East Asian Summer Monsoon. The climate teleconnection patterns explored include the Indian Ocean Dipole, E1 Niño Southern Oscillation, and the Pacific Decadal Oscillation. The wavelet transform and wavelet coherence methods are used to analyze the karst hydrological processes in the NKS Basin, and reveal the relations between the climate indices with precipitation and the spring discharge. The study results indicate that both the monsoons and the climate teleconnections significantly affect precipitation in the NKS Basin. The time scales that the monsoons resonate with precipitation are strongly concentrated on the time scales of 0.5-, 1-, 2.5- and 3.5-year, and that climate teleconnections resonate with precipitation are relatively weak and diverged from 0.5-, 1-, 2-, 2.5-, to 8-year time scales, respectively. Because the climate signals have to overcome the resistance of heterogeneous aquifers before reaching spring discharge, with high energy, the strong climate signals (e.g. monsoons) are able to penetrate through aquifers and act on spring discharge. So the spring discharge is more strongly affected by monsoons than the climate teleconnections. During the groundwater flow process, the precipitation signals will be attenuated, delayed, merged, and changed by karst aquifers. Therefore, the coherence coefficients between the spring discharge and climate indices are smaller than those between precipitation and climate indices. Further, the fluctuation of the spring discharge is not coincident with that of precipitation in most

  5. Model Interpretation of Climate Signals: Application to the Asian Monsoon Climate

    Science.gov (United States)

    Lau, William K. M.

    2002-01-01

    This is an invited review paper intended to be published as a Chapter in a book entitled "The Global Climate System: Patterns, Processes and Teleconnections" Cambridge University Press. The author begins with an introduction followed by a primer of climate models, including a description of various modeling strategies and methodologies used for climate diagnostics and predictability studies. Results from the CLIVAR Monsoon Model Intercomparison Project (MMIP) were used to illustrate the application of the strategies to modeling the Asian monsoon. It is shown that state-of-the art atmospheric GCMs have reasonable capability in simulating the seasonal mean large scale monsoon circulation, and response to El Nino. However, most models fail to capture the climatological as well as interannual anomalies of regional scale features of the Asian monsoon. These include in general over-estimating the intensity and/or misplacing the locations of the monsoon convection over the Bay of Bengal, and the zones of heavy rainfall near steep topography of the Indian subcontinent, Indonesia, and Indo-China and the Philippines. The intensity of convection in the equatorial Indian Ocean is generally weaker in models compared to observations. Most important, an endemic problem in all models is the weakness and the lack of definition of the Mei-yu rainbelt of the East Asia, in particular the part of the Mei-yu rainbelt over the East China Sea and southern Japan are under-represented. All models seem to possess certain amount of intraseasonal variability, but the monsoon transitions, such as the onset and breaks are less defined compared with the observed. Evidences are provided that a better simulation of the annual cycle and intraseasonal variability is a pre-requisite for better simulation and better prediction of interannual anomalies.

  6. Impacts of Land Process on the Onset and Evolution of Asian Summer Monsoon in the NCEP Climate Forecast System

    Institute of Scientific and Technical Information of China (English)

    Song YANG; WEN Min; Rongqian YANG; Wayne HIGGINS; ZHANG Renhe

    2011-01-01

    Impacts of land models and initial land conditions (ICs) on the Asian summer monsoon,especially its onset,were investigated using the NCEP Climate Forecast System (CFS).Two land models,the Oregon State University (OSU) land model and the NCEP,OSU,Air Force,and Hydrologic Research Laboratory (Noah) land model,were used to get parallel experiments.The experiments also used land ICs from the NCEP/Department of Energy (DOE) Global Reanalysis 2 (GR2) and the Global Land Data Assimilation System (GLDAS).Previous studies have demonstrated that,a systematic weak bias appears in the modeled monsoon,and this bias may be related to a cold bias over the Asian land mass.Results of the current study show that replacement of the OSU land model by the Noah land model improved the model's cold bias and produced improved monsoon precipitation and circulation patterns.The CFS predicted monsoon with greater proficiency in El Ni(n)o years,compared to La Ni(n)a years,and the Noah model performed better than the OSU model in monsoon predictions for individual years.These improvements occurred not only in relation to monsoon onset in late spring but also to monsoon intensity in summer.Our analysis of the monsoon features over the India peninsula,the Indo-China peninsula,and the South Chinese Sea indicates different degrees of improvement.Furthermore,a change in the land models led to more remarkable improvement in monsoon prediction than did a change from the GR2 land ICs to the GLDAS land ICs.

  7. Mid-Pliocene East Asian monsoon climate simulated in the PlioMIP

    Directory of Open Access Journals (Sweden)

    R. Zhang

    2013-09-01

    Full Text Available Based on simulations with 15 climate models in the Pliocene Model Intercomparison Project (PlioMIP, the regional climate of East Asia (focusing on China during the mid-Pliocene is investigated in this study. Compared to the pre-industrial, the multi-model ensemble mean (MMM of all models shows the East Asian summer winds (EASWs largely strengthen in monsoon China, and the East Asian winter winds (EAWWs strengthen in south monsoon China but slightly weaken in north monsoon China in the mid-Pliocene. The MMM of all models also illustrates a warmer and wetter mid-Pliocene climate in China. The simulated weakened mid-Pliocene EAWWs in north monsoon China and intensified EASWs in monsoon China agree well with geological reconstructions. However, there is a large model–model discrepancy in simulating mid-Pliocene EAWW, which should be further addressed in the future work of PlioMIP.

  8. Subseasonal features of the Asian summer monsoon in the NCEP climate forecast system

    Institute of Scientific and Technical Information of China (English)

    Song YANG; WEN Min; R Wayne HIGGINS

    2008-01-01

    The operational climate forecast system (CFS) of the US National Centers for Environmental Prediction provides climate predic-tions over the world, and CFS products are becoming an important source of information for regional climate predictions in many Asian countries where monsoon climate dominates. Recent studies have shown that, on monthly-to-seasonal time-scales, the CFS is highly skillful in simulating and predicting the variability of the Asian monsoon. The higher-frequency variability of the Asian summer monsoon in the CFS is analyzed, using output from a version with a spectral triangular truncation of 126 waves in horizon-tal and 64 sigma layers in vertical, focusing on synoptic, quasi-biweekly, and intraseasonal time-scales. The onset processes of different regional monsoon components were investigated within Asia. Although the CFS generally overestimates variability of mon-soon on these time-scales, it successfully captures many major features of the variance patterns, especially for the synoptic time-scale. The CFS also captures the timing of summer monsoon onsets over India and the Indo-China Peninsula. However, it encoun-ters difficulties in simulating the onset of the South China Sea monsoon. The success and failure of the CFS in simulating the onset of monsoon precipitation can also be seen from the associated features of simulated atmospheric circulation processes. Overall, the CFS is capable of simulating the synoptic-to-intraseasonal variability of the Asian summer monsoon with skills. As for seasonal-to-interannual time-scales shown previously, the model is expected to possess a potential for skillful predictions of the high-frequencyvariability of the Asian monsoon.

  9. Mid-Pliocene East Asian monsoon climate simulated in the PlioMIP

    OpenAIRE

    Zhang, R.; Yan, Q.; Z. S. Zhang; Jiang, D.; B. L. Otto-Bliesner; A. M. Haywood; D. J. Hill; Dolan, A. M.; Stepanek, C.; Lohmann, G.; Contoux, C.; F. Bragg; Chan, W.-L.; Chandler, M. A.; A. Jost

    2013-01-01

    Based on the simulations with fifteen climate models in the Pliocene Model Intercomparison Project (PlioMIP), the regional climate of East Asia (focusing on China) during the mid-Pliocene is investigated in this study. Compared to the pre-industrial, the multi-model ensemble mean (MMM) of all models shows the East Asian summer wind (EASW) largely strengthens in monsoon China, and the East Asian winter wind (EAWW) strengthens in south monsoon China but slightly weakens in north monsoon China i...

  10. Mid-Holocene Climate Variations Recorded by Palaeolake in Marginal Area of East Asian Monsoon: A Multi-proxy Study

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Traditionally, the mid-Holocene in most parts of China was thought to be warmer with higher precipitation,resulting from a strong Asian summer monsoon. However, some recent researches have proposed a mid-Holocene drought interval of millennial-scale in East Asian monsoon margin areas. Thus whether mid-Holocene was dry or humid remains an open issue. Here, Zhuyeze palaeolake, the terminal lake of the Shiyang River Drainage lying in Asian monsoon marginal areas, was selected for reconstructing the details of climate variations during the Holocene, especially mid-Holocene,on the basis ora sedimentological analysis. Qingtu Lake (QTL) section of 6.92m depth was taken from Zhuyeze palaeolake. Multi-proxy analysis of QTL section, including grain size, carbonate, TOC, C/N and δ13C of organic matter, was used to document regional climatic changes during 9-3 cal ka B.P. The record shows a major environmental change at 9.0-7.8 cal ka B.P., attributed to a climate trend towards warmth and humidity. This event was followed by a typical regional drought event which occurred during 7.8-7.5 cal ka B.P. And a warm and humid climate prevailed from 7.5 to 5.0 cal ka B.P., attributed to the warm/humid Holocene Optimum in this region. After that, the climate gradually became drier.Moreover, comparison of the climate record from this paper with the summer insolation at 30°N indicates that the climate pattern reflecting the Asian monsoon changes was caused by insolation change.

  11. A study on the role of land-atmosphere coupling on the south Asian monsoon climate variability using a regional climate model

    Science.gov (United States)

    Unnikrishnan, C. K.; Rajeevan, M.; Vijaya Bhaskara Rao, S.

    2017-02-01

    Land-atmosphere coupling over the south Asian monsoon region is examined using a regional climate model. For this purpose, the Weather Research and Forecasting (WRF) model with a resolution of 45 km was used. In the control experiment (CTL), the model was integrated from the year 2000 to 2011 and allowed the soil moisture interaction with the atmosphere using a coupled land surface model. In the second experiment (CSM), the soil moisture evolution at each time step was replaced with the climatology of soil moisture taken from the control run. The results reveal that land-atmosphere coupling plays a critical role in influencing the south Asian monsoon climate variability. Soil moisture is found to have stronger impacts on daily maximum temperature compared to minimum temperature. Soil moisture also makes a significant contribution to monsoon rainfall variability over the monsoon region. The coupling strength for large-scale rainfall is found to be higher compared to that of cumulus rainfall. Soil moisture is found more strongly coupled to sensible heat flux over most of the monsoon region.

  12. THE CLIMATIC CHARACTERISTICS OF SUMMER MONSOON ONSET OVER THE SOUTH CHINA SEA I.40-YEAR AVERAGE

    Institute of Scientific and Technical Information of China (English)

    冯瑞权; 王安宇; 吴池胜; 林建恒; 古志明; 林文实; 谭志文

    2002-01-01

    By using 40-year NCEP reanalysis daily data (1958-1997),we have analyzed the climatic characteristics of summer monsoon onset in the South China Sea (105(E ~120(E,5(N~20(N,to be simplified as SCS in the text followed) pentad by pentad (5 days).According to our new definition,in the monsoon area of the SCS two of the following conditions should be satisfied:1) At 850hPa,the southwest winds should be greater than 2m/s.2) At 850 hPa,should be greater than 335(K.The new definition means that the summer monsoon is the southwest winds with high temperature and high moisture.The onset of the SCS summer monsoon is defined to start when one half of the SCS area (105(E~120(E,5(N~20(N) is controlled by the summer monsoon.The analyzed results revealed the following:1) The summer monsoon in the SCS starts to build up abruptly in the 4th pentad in May.2) The summer monsoon onset in the SCS is resulted from the development and intensification of southwesterly monsoon in the Bay of Bengal.3) The onset of the summer monsoon and establishment of the summer monsoon rainfall season in the SCS occur simultaneously.4) During the summer monsoon onset in the SCS,troughs deepen and widen quickly in the lower troposphere of the India;the subtropical high in the Western Pacific moves eastward off the SCS in the middle troposphere;the easterly advances northward over the SCS in the upper troposphere.

  13. Reduction of uncertainty associated with future changes in Indian summer monsoon projected by climate models and assessment of monsoon teleconnections

    Science.gov (United States)

    Rajendran, Kavirajan; Surendran, Sajani; Kitoh, Akio; Varghese, Stella Jes

    2016-05-01

    Coupled Model Intercomparison Project phase 5 (CMIP5) coupled global climate model (CGCM) Representative Concentration Pathway (RCP) simulations project clear future temperature increase but diverse changes in Indian summer monsoon rainfall (ISMR) with substantial inter-model spread. Robust signals of projected changes are derived based on objective criteria and the physically consistent simulations with the highest reliability suggest future reduction in the frequency of light rainfall but increase in high to extreme rainfall. The role of equatorial Indian and Pacific Oceans on the projected changes in monsoon rainfall is investigated. The results of coupled model projections are also compared with the corresponding projections from high resolution AGCM time-slice, multi-physics and multi-forcing ensemble experiments.

  14. THE EAST ASIAN SUBTROPICAL SUMMER MONSOON INDEX AND ITS RELATION WITH THE CLIMATE ANOMALIES IN CHINA

    Institute of Scientific and Technical Information of China (English)

    LIU Xuan-fei; WANG-Jing

    2007-01-01

    A new East Asian subtropical summer monsoon circulation index is defined, where the barotropic and baroclinic components of circulation are included. Results show that this index can well indicate the interannual variability of summer precipitation and temperature anomalies in China. A strong monsoon is characterized by more rainfall in the Yellow River basin and northern China, less rainfall in the Yangtze River basin, and more rainfall in south and southeast China, in association with higher temperature in most areas of China. Furthermore, comparison is made between the index proposed in this paper and other monsoon indexes in representing climate anomalies in China.

  15. Links between Indo-Pacific climate variability and drought in the Monsoon Asia Drought Atlas

    Science.gov (United States)

    Ummenhofer, Caroline C.; D'Arrigo, Rosanne D.; Anchukaitis, Kevin J.; Buckley, Brendan M.; Cook, Edward R.

    2013-03-01

    Drought patterns across monsoon and temperate Asia over the period 1877-2005 are linked to Indo-Pacific climate variability associated with the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). Using the Monsoon Asia Drought Atlas (MADA) composed of a high-resolution network of hydroclimatically sensitive tree-ring records with a focus on the June-August months, spatial drought patterns during El Niño and IOD events are assessed as to their agreement with an instrumental drought index and consistency in the drought response amongst ENSO/IOD events. Spatial characteristics in drought patterns are related to regional climate anomalies over the Indo-Pacific basin, using reanalysis products, including changes in the Asian monsoon systems, zonal Walker circulation, moisture fluxes, and precipitation. A weakening of the monsoon circulation over the Indian subcontinent and Southeast Asia during El Niño events, along with anomalous subsidence over monsoon Asia and reduced moisture flux, is reflected in anomalous drought conditions over India, Southeast Asia and Indonesia. When an IOD event co-occurs with an El Niño, severe drought conditions identified in the MADA for Southeast Asia, Indonesia, eastern China and central Asia are associated with a weakened South Asian monsoon, reduced moisture flux over China, and anomalous divergent flow and subsidence over Indonesia. Insights into the relative influences of Pacific and Indian Ocean variability for Asian monsoon climate on interannual to decadal and longer timescales, as recorded in the MADA, provide a useful tool for assessing long-term changes in the characteristics of Asian monsoon droughts in the context of Indo-Pacific climate variability.

  16. The South American monsoon variability over the last millennium in climate models

    Science.gov (United States)

    Rojas, Maisa; Arias, Paola A.; Flores-Aqueveque, Valentina; Seth, Anji; Vuille, Mathias

    2016-08-01

    In this paper we assess South American monsoon system (SAMS) variability in the last millennium as depicted by global coupled climate model simulations. High-resolution proxy records for the South American monsoon over this period show a coherent regional picture of a weak monsoon during the Medieval Climate Anomaly and a stronger monsoon during the Little Ice Age (LIA). Due to the small external forcing during the past 1000 years, model simulations do not show very strong temperature anomalies over these two specific periods, which in turn do not translate into clear precipitation anomalies, in contrast with the rainfall reconstructions in South America. Therefore, we used an ad hoc definition of these two periods for each model simulation in order to account for model-specific signals. Thereby, several coherent large-scale atmospheric circulation anomalies are identified. The models feature a stronger monsoon during the LIA associated with (i) an enhancement of the rising motion in the SAMS domain in austral summer; (ii) a stronger monsoon-related upper-tropospheric anticyclone; (iii) activation of the South American dipole, which results in a poleward shift of the South Atlantic Convergence Zone; and (iv) a weaker upper-level subtropical jet over South America. The diagnosed changes provide important insights into the mechanisms of these climate anomalies over South America during the past millennium.

  17. Understanding land surface response to changing South Asian monsoon in a warming climate

    Directory of Open Access Journals (Sweden)

    M. V. S. Ramarao

    2015-05-01

    Full Text Available Recent studies have drawn attention to a significant weakening trend of the South Asian monsoon circulation and an associated decrease in regional rainfall during the last few decades. While surface temperatures over the region have steadily risen during this period, most of the CMIP (Coupled Model Intercomparison Project global climate models have difficulties in capturing the observed decrease of monsoon precipitation, thus limiting our understanding of the regional land surface response to monsoonal changes. This problem is investigated by performing two long-term simulation experiments, with and without anthropogenic forcing, using a variable resolution global climate model having high-resolution zooming over the South Asian region. The present results indicate that anthropogenic effects have considerably influenced the recent weakening of the monsoon circulation and decline of precipitation. It is seen that the simulated increase of surface temperature over the Indian region during the post-1950s is accompanied by a significant decrease of monsoon precipitation and soil moisture. Our analysis further reveals that the land surface response to decrease of soil moisture is associated with significant reduction in evapotranspiration over the Indian land region. A future projection, based on the representative concentration pathway 4.5 (RCP4.5 scenario of the Intergovernmental panel on Climate Change (IPCC, using the same high-resolution model indicates the possibility for detecting the summer-time soil drying signal over the Indian region during the 21st century, in response to climate change. While these monsoon hydrological changes have profound socioeconomic implications, the robustness of the high-resolution simulations provides deeper insights and enhances our understanding of the regional land surface response to the changing South Asian monsoon.

  18. Three centuries of Myanmar monsoon climate variability inferred from teak tree rings

    Science.gov (United States)

    D'Arrigo, Rosanne; Palmer, Jonathan; Ummenhofer, Caroline C.; Kyaw, Nyi Nyi; Krusic, Paul

    2011-12-01

    Asian monsoon extremes critically impact much of the globe’s population. Key gaps in our understanding of monsoon climate remain due to sparse coverage of paleoclimatic information, despite intensified recent efforts. Here we describe a ring width chronology of teak, one of the first high-resolution proxy records for the nation of Myanmar. Based on 29 samples from 20 living trees and spanning from 1613-2009, this record, from the Maingtha forest reserve north of Mandalay, helps fill a substantial gap in spatial coverage of paleoclimatic records for monsoon Asia. Teak growth is positively correlated with rainfall and Palmer Drought Severity Index variability over Myanmar, during and prior to the May-September monsoon season (e.g., r = 0.38 with Yangon rainfall, 0.001, n 68). Importantly, this record also correlates significantly with larger-scale climate indices, including core Indian rainfall (23°N, 76°E a particularly sensitive index of the monsoon), and the El Niño-Southern Oscillation (ENSO). The teak ring width value following the so-called 1997-98 El Niño of the Century suggests that this was one of the most severe droughts in the past ˜300 years in Myanmar. Evidence for past dry conditions inferred for Myanmar is consistent with tree-ring records of decadal megadroughts developed for Thailand and Vietnam. These results confirm the climate signature related to monsoon rainfall in the Myanmar teak record and the considerable potential for future development of climate-sensitive chronologies from Myanmar and the broader region of monsoon Asia.

  19. Regional climate model experiments to investigate the Asian monsoon in the Late Miocene

    Directory of Open Access Journals (Sweden)

    H. Tang

    2011-08-01

    Full Text Available The Late Miocene (11.6–5.3 Ma is a crucial period in the history of the Asian monsoon. Significant changes in the Asian climate regime have been documented for this period, which saw the formation of the modern Asian monsoon system. However, the spatiotemporal structure of these changes is still ambiguous, and the associated mechanisms are debated. Here, we present a simulation of the average state of the Asian monsoon climate for the Tortonian (11–7 Ma using the regional climate model CCLM3.2. We employ relatively high spatial resolution (1° × 1° and adapt the physical boundary conditions such as topography, land-sea distribution and vegetation in the regional model to represent the Late Miocene. As climatological forcing, the output of a Tortonian run with a fully-coupled atmosphere-ocean general circulation model is used. Our regional Tortonian run shows a stronger-than-present East Asian winter monsoon wind as a result of the enhanced mid-latitude westerly wind of our global forcing and the lowered present-day northern Tibetan Plateau in the regional model. The summer monsoon circulation is generally weakened in our regional Tortonian run compared to today. However, the changes of summer monsoon precipitation exhibit major regional differences. Precipitation decreases in northern China and northern India, but increases in southern China, the western coast and the southern tip of India. This can be attributed to the changes in both the regional topography (e.g. the lower northern Tibetan Plateau and the global climate conditions (e.g. the higher sea surface temperature. The spread of dry summer conditions over northern China and northern Pakistan in our Tortonian run further implies that the monsoonal climate may not have been fully established in these regions in the Tortonian. Compared with the global model, the high resolution regional model highlights the spatial differences of the Asian monsoon climate in the Tortonian, and better

  20. Prediction of Monthly Summer Monsoon Rainfall Using Global Climate Models Through Artificial Neural Network Technique

    Science.gov (United States)

    Nair, Archana; Singh, Gurjeet; Mohanty, U. C.

    2017-08-01

    The monthly prediction of summer monsoon rainfall is very challenging because of its complex and chaotic nature. In this study, a non-linear technique known as Artificial Neural Network (ANN) has been employed on the outputs of Global Climate Models (GCMs) to bring out the vagaries inherent in monthly rainfall prediction. The GCMs that are considered in the study are from the International Research Institute (IRI) (2-tier CCM3v6) and the National Centre for Environmental Prediction (Coupled-CFSv2). The ANN technique is applied on different ensemble members of the individual GCMs to obtain monthly scale prediction over India as a whole and over its spatial grid points. In the present study, a double-cross-validation and simple randomization technique was used to avoid the over-fitting during training process of the ANN model. The performance of the ANN-predicted rainfall from GCMs is judged by analysing the absolute error, box plots, percentile and difference in linear error in probability space. Results suggest that there is significant improvement in prediction skill of these GCMs after applying the ANN technique. The performance analysis reveals that the ANN model is able to capture the year to year variations in monsoon months with fairly good accuracy in extreme years as well. ANN model is also able to simulate the correct signs of rainfall anomalies over different spatial points of the Indian domain.

  1. Orbital control on late Miocene climate and the North African monsoon : Insight from an ensemble of sub-precessional simulations

    NARCIS (Netherlands)

    Marzocchi, A.; Lunt, D. J.; Flecker, R.; Bradshaw, C. D.; Farnsworth, A.; Hilgen, F. J.

    2015-01-01

    Orbital forcing is a key climate driver over multi-millennial timescales. In particular, monsoon systems are thought to be driven by orbital cyclicity, especially by precession. Here, we analyse the impact of orbital forcing on global climate with a particular focus on the North African monsoon, by

  2. Future projection of Indian summer monsoon variability under climate change scenario: An assessment from CMIP5 climate models

    Science.gov (United States)

    Sharmila, S.; Joseph, S.; Sahai, A. K.; Abhilash, S.; Chattopadhyay, R.

    2015-01-01

    In this study, the impact of enhanced anthropogenic greenhouse gas emissions on the possible future changes in different aspects of daily-to-interannual variability of Indian summer monsoon (ISM) is systematically assessed using 20 coupled models participated in the Coupled Model Inter-comparison Project Phase 5. The historical (1951-1999) and future (2051-2099) simulations under the strongest Representative Concentration Pathway have been analyzed for this purpose. A few reliable models are selected based on their competence in simulating the basic features of present-climate ISM variability. The robust and consistent projections across the selected models suggest substantial changes in the ISM variability by the end of 21st century indicating strong sensitivity of ISM to global warming. On the seasonal scale, the all-India summer monsoon mean rainfall is likely to increase moderately in future, primarily governed by enhanced thermodynamic conditions due to atmospheric warming, but slightly offset by weakened large scale monsoon circulation. It is projected that the rainfall magnitude will increase over core monsoon zone in future climate, along with lengthening of the season due to late withdrawal. On interannual timescales, it is speculated that severity and frequency of both strong monsoon (SM) and weak monsoon (WM) might increase noticeably in future climate. Substantial changes in the daily variability of ISM are also projected, which are largely associated with the increase in heavy rainfall events and decrease in both low rain-rate and number of wet days during future monsoon. On the subseasonal scale, the model projections depict considerable amplification of higher frequency (below 30 day mode) components; although the dominant northward propagating 30-70 day mode of monsoon intraseasonal oscillations may not change appreciably in a warmer climate. It is speculated that the enhanced high frequency mode of monsoon ISOs due to increased GHG induced warming

  3. Earth as diode: monsoon source of the orbital ~100 ka climate cycle

    Directory of Open Access Journals (Sweden)

    R. Y. Anderson

    2010-08-01

    Full Text Available A potential source for Earth's enigmatic ~100 ka climate cycle, which is found in many ancient geological records at low latitudes and also in the pacing of glaciation during the late Pleistocene, is traced to a climatic rectifying process inherent in the monsoon. Seasonal information needed to identify the rectifying mechanism is preserved within varves of a continuous, 200 ka recording of annual maximum surface temperature (Tmax from the equator of Western Pangea. Specific seasonal reactions recorded in varves show how the monsoon reacted to seasonal differences in insolation at equinox to produce a 11.7 ka semi-precession cycle in Tmax. At solstice, anti-phasing of insolation in the Northern and Southern Hemispheres, intensified and focused by a highly asymmetric Pangea relative to the equator, produced a strong equatorial maritime monsoon that performed a nonlinear rectifying function similar to that of a simple rectifying diode. Expressed in the resulting varve series are substantial cycles in Tmax of 100 ka, 23.4 ka, and 11.7 ka. Importantly, any external or internal forcing of the tropical (monsoon climate system at higher-than-orbital frequencies (e.g. solar, ENSO should also be amplified at Milankovitch frequencies by the monsoon.

  4. Impact of Anthropogenic Climate Change on the East Asian Summer Monsoon

    Science.gov (United States)

    Burke, Claire; Stott, Peter

    2017-07-01

    The East Asian summer monsoon (EASM) is important for bringing rainfall to large areas of China. Historically, variations in the EASM have had major impacts including flooding and drought. We present an analysis of the impact of anthropogenic climate change on EASM rainfall in Eastern China using a newly updated attribution system. Our results suggest that anthropogenic climate change has led to an overall decrease in total monsoon rainfall over the past 65 years, and an increased number of dry days. However the model also predicts that anthropogenic forcings have caused the most extreme heavy rainfall events to become shorter in duration and more intense. With the potential for future changes in aerosol and greenhouse gas emissions, historical trends in monsoon rainfall may not be indicative of future changes, although extreme rainfall is projected to increase over East Asia with continued warming in the region.

  5. Climatic Changes and Evaluation of Their Effects on Agriculture in Asian Monsoon Region- A project of GRENE-ei programs in Japan

    Science.gov (United States)

    Mizoguchi, M.; Matsumoto, J.; Takahashi, H. G.; Tanaka, K.; Kuwagata, T.

    2015-12-01

    It is important to predict climate change correctly in regional scale and to build adaptation measures and mitigation measures in the Asian monsoon region where more than 60 % of the world's population are living. The reliability of climate change prediction model is evaluated by the reproducibility of past climate in general. However, because there are many developing countries in the Asian monsoon region, adequate documentations of past climate which are needed to evaluate the climate reproducibility have not been prepared. In addition, at present it is difficult to get information on wide-area agricultural meteorological data which affect the growth of agricultural crops when considering the impact on agriculture of climate. Therefore, we have started a research project entitled "Climatic changes and evaluation of their effects on agriculture in Asian monsoon region (CAAM)" under the research framework of the Green Network of Excellence (GRENE) for the Japanese fiscal years from 2011 to 2015 supported by the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT). This project aims to improve the reliability of future climate prediction and to develop the information platform which will be useful to design adaptation and mitigation strategies in agriculture against the predicted climatic changes in Asian monsoon regions. What is GRENE?Based on the new growth strategy which was approved by the Cabinet of Japan in June 2010, Green Network of Excellence program (GRENE) has started under MEXT from FY 2011. The objectives of this program are that the domestic leading universities work together strategically and promote a comprehensive human resource development and research of the highest level in the world while sharing research resources and research goals. In the field of environmental information, it is required that universities and research institutions, which are working on issues such as adaptation to climate change, cooperate to

  6. Regional climate model experiments to investigate the Asian monsoon in the Late Miocene

    Directory of Open Access Journals (Sweden)

    H. Tang

    2011-03-01

    Full Text Available The Late Miocene (11.6–5.3 Ma is a crucial period for the Asian monsoon evolution. However, the spatiotemporal changes of the Asian monsoon system in the Late Miocene are still ambiguous, and the mechanisms responsible for these changes are debated. Here, we present a simulation of the Asian monsoon climate (0 to 60° N and 50 to 140° E in the Tortonian (11–7 Ma using the regional climate model CCLM3.2. We employ relatively high spatial resolution (1° × 1° and adapt the physical boundary conditions such as topography, land-sea distribution and vegetation in the regional model to represent the Late Miocene. As climatological forcing, the output of a Tortonian run with a fully-coupled atmosphere-ocean general circulation model is used. Our results show a stronger-than-present E-Asian winter monsoon wind in the Tortonian, as a result of the enhanced mid-latitude westerly wind of our global forcing and the lowered northern Tibetan Plateau in the regional model. The summer monsoon circulation is generally weakened in our regional Tortonian run compared to today. However, the changes of summer monsoon precipitation exhibit major regional differences. The precipitation decreases in N-China and N-India, but increases in S-China, the western coast and the southern tip of India. This can be attributed to the combined effect of both the regional topographical changes and the other forcings related to our global model. The spread of the dry summer conditions over N-China and NW-India further implies that the monsoonal climate may not be fully established over these regions in the Tortonain. Compared with the global model, the high resolution regional model highlights the spatial differences of the Asian monsoon climate in the Tortonian, and better characterizes the convective activity and its response to topographical changes. It therefore provides a useful and compared to global models complementary tool to improve our understanding of the Asian

  7. A mechanism for land-ocean contrasts in global monsoon trends in a warming climate

    Energy Technology Data Exchange (ETDEWEB)

    Fasullo, J. [National Center for Atmospheric Research, CAS/NCAR, Boulder, CO (United States)

    2012-09-15

    A central paradox of the global monsoon record involves reported decreases in rainfall over land during an era in which the global hydrologic cycle is both expected and observed to intensify. It is within this context that this work develops a physical basis for both interpreting the observed record and anticipating changes in the monsoons in a warming climate while bolstering the concept of the global monsoon in the context of shared feedbacks. The global-land monsoon record across multiple reanalyses is first assessed. Trends that in other studies have been taken as real are shown to likely be spurious as a result of changes in the assimilated data streams both prior to and during the satellite era. Nonetheless, based on satellite estimates, robust increases in monsoon rainfall over ocean do exist and a physical basis for this land-ocean contrast remains lacking. To address the contrast's causes, simulated trends are therefore assessed. While projections of total rainfall are inconsistent across models, the robust land-ocean contrast identified in observations is confirmed. A feedback mechanism is proposed rooted in the facts that land areas warm disproportionately relative to ocean, and onshore flow is the chief source of monsoonal moisture. Reductions in lower tropospheric relative humidity over land domains are therefore inevitable and these have direct consequences for the monsoonal convective environment including an increase in the lifting condensation level and a shift in the distribution of convection generally towards less frequent and potentially more intense events. The mechanism is interpreted as an important modulating influence on the ''rich-get-richer'' mechanism. Caveats for regional monsoons exist and are discussed. (orig.)

  8. A model perspective on orbital forcing of monsoons and Mediterranean climate using EC-Earth

    NARCIS (Netherlands)

    Bosmans, J.H.C.|info:eu-repo/dai/nl/344765490

    2014-01-01

    This thesis focuses on orbitally forced changes of monsoons and Mediterranean climate. Changes in the shape of the Earths orbit around the Sun and its rotational axis govern the seasonal and latitudinal distribution of incoming solar radiation on time scales of thousands to millions of years. The

  9. A model perspective on orbital forcing of monsoons and Mediterranean climate using EC-Earth

    NARCIS (Netherlands)

    Bosmans, J.H.C.

    2014-01-01

    This thesis focuses on orbitally forced changes of monsoons and Mediterranean climate. Changes in the shape of the Earths orbit around the Sun and its rotational axis govern the seasonal and latitudinal distribution of incoming solar radiation on time scales of thousands to millions of years. The th

  10. Effects of crop growth and development on regional climate: a case study over East Asian monsoon area

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Feng [Chinese Academy of Sciences, LASG, Institute of Atmospheric Physics, Beijing (China); Zhejiang Institute of Meteorological Sciences, Hangzhou (China); Xie, Zhenghui [Chinese Academy of Sciences, LASG, Institute of Atmospheric Physics, Beijing (China)

    2012-06-15

    In this study, the CERES phenological growth and development functions were implemented into the regional climate model, RegCM3 to give a model denoted as RegCM3{sub C}ERES. This model was used to represent interactions between regional climate and crop growth processes. The effects of crop growth and development processes on regional climate were then studied based on two 20-year simulations over the East Asian monsoon area conducted using the original regional climate model RegCM3, and the coupled RegCM3{sub C}ERES model. The numerical experiments revealed that incorporating the crop growth and development processes into the regional climate model reduced the root mean squared error of the simulated precipitation by 2.2-10.7% over north China, and the simulated temperature by 5.5-30.9% over the monsoon region in eastern China. Comparison of the simulated results obtained using RegCM3{sub C}ERES and RegCM3 showed that the most significant changes associated with crop modeling were the changes in leaf area index which in turn modify the aspects of surface energy and water partitions and lead to moderate changes in surface temperature and, to some extent, rainfall. Further analysis revealed that a robust representation of seasonal changes in plant growth and developmental processes in the regional climate model changed the surface heat and moisture fluxes by modifying the vegetation characteristics, and that these differences in simulated surface fluxes resulted in different structures of the boundary layer and ultimately affected the convection. The variations in leaf area index and fractional vegetation cover changed the distribution of evapotranspiration and heat fluxes, which could potentially lead to anomalies in geopotential height, and consequently influenced the overlying atmospheric circulation. These changes would result in redistribution of the water and energy through advection. Nevertheless, there are significant uncertainties in modeling how monsoon

  11. Eocene prevalence of monsoon-like climate over eastern China reflected by hydrological dynamics

    Science.gov (United States)

    Wang, Dehai; Lu, Shicong; Han, Shuang; Sun, Xiaoyan; Quan, Cheng

    2013-01-01

    Hydrological dynamics of sedimentary basins are essential for understanding regional climatic pattern in the geological past. In previous qualitative studies lithologically depending on the occurrence of featured sedimentary rocks, the Eocene climate of China had been subdivided into three latitudinal zones, with one subtropical high-controlled arid zone throughout middle China, and two humid zones respectively in the north and south. However, recent advances on mammalian fauna distribution, plant fossil-based quantitative paleoclimatic reconstruction, and modeling experiment jointly suggest that the relatively humid monsoonal climate might have prevailed over the territory. Here we examine and compare sedimentary sequences of 10 Eocene sections across eastern China, and hence the lake level fluctuations, to discuss the nature of climate type. Our results show that, instead of the categorically zonal pattern, the hydroclimate dynamics is intensified landward. This is demonstrated by the fact that, in contrast to the wide developed coal layers around the periphery, evaporites are growingly occurred endocentrically to the central part of middle China. However, although we have had assumed that all evaporites are indicator of extreme aridity, the highly oscillated climate in the central part of middle China was humid in the majority of the Eocene, distinct from permanent arid as seen in deserts or steppe along modern horse latitude. From the upcountry distribution pattern of the Eocene hydrological dynamics, it appears that the relatively dry climate in central China was caused by the impact of continentality or rain shadow effect under monsoonal, or monsoon-like climate.

  12. Uncertainties in the regional climate models simulations of South-Asian summer monsoon and climate change

    Science.gov (United States)

    Syed, F. S.; Iqbal, Waheed; Syed, Ahsan Ali Bukhari; Rasul, G.

    2014-04-01

    The uncertainties in the regional climate models (RCMs) are evaluated by analyzing the driving global data of ERA40 reanalysis and ECHAM5 general circulation models, and the downscaled data of two RCMs (RegCM4 and PRECIS) over South-Asia for the present day simulation (1971-2000) of South-Asian summer monsoon. The differences between the observational datasets over South-Asia are also analyzed. The spatial and the quantitative analysis over the selected climatic regions of South-Asia for the mean climate and the inter-annual variability of temperature, precipitation and circulation show that the RCMs have systematic biases which are independent from different driving datasets and seems to come from the physics parameterization of the RCMs. The spatial gradients and topographically-induced structure of climate are generally captured and simulated values are within a few degrees of the observed values. The biases in the RCMs are not consistent with the biases in the driving fields and the models show similar spatial patterns after downscaling different global datasets. The annual cycle of temperature and rainfall is well simulated by the RCMs, however the RCMs are not able to capture the inter-annual variability. ECHAM5 is also downscaled for the future (2071-2100) climate under A1B emission scenario. The climate change signal is consistent between ECHAM5 and RCMs. There is warming over all the regions of South-Asia associated with increasing greenhouse gas concentrations and the increase in summer mean surface air temperature by the end of the century ranges from 2.5 to 5 °C, with maximum warming over north western parts of the domain and 30 % increase in rainfall over north eastern India, Bangladesh and Myanmar.

  13. From monsoon to marine productivity in the Arabian Sea: insights from glacial and interglacial climates

    Science.gov (United States)

    Le Mézo, Priscilla; Beaufort, Luc; Bopp, Laurent; Braconnot, Pascale; Kageyama, Masa

    2017-07-01

    The current-climate Indian monsoon is known to boost biological productivity in the Arabian Sea. This paradigm has been extensively used to reconstruct past monsoon variability from palaeo-proxies indicative of changes in surface productivity. Here, we test this paradigm by simulating changes in marine primary productivity for eight contrasted climates from the last glacial-interglacial cycle. We show that there is no straightforward correlation between boreal summer productivity of the Arabian Sea and summer monsoon strength across the different simulated climates. Locally, productivity is fuelled by nutrient supply driven by Ekman dynamics. Upward transport of nutrients is modulated by a combination of alongshore wind stress intensity, which drives coastal upwelling, and by a positive wind stress curl to the west of the jet axis resulting in upward Ekman pumping. To the east of the jet axis there is however a strong downward Ekman pumping due to a negative wind stress curl. Consequently, changes in coastal alongshore stress and/or curl depend on both the jet intensity and position. The jet position is constrained by the Indian summer monsoon pattern, which in turn is influenced by the astronomical parameters and the ice sheet cover. The astronomical parameters are indeed shown to impact wind stress intensity in the Arabian Sea through large-scale changes in the meridional gradient of upper-tropospheric temperature. However, both the astronomical parameters and the ice sheets affect the pattern of wind stress curl through the position of the sea level depression barycentre over the monsoon region (20-150° W, 30° S-60° N). The combined changes in monsoon intensity and pattern lead to some higher glacial productivity during the summer season, in agreement with some palaeo-productivity reconstructions.

  14. Changes in the Asian monsoon climate during 1700-1850 induced by preindustrial cultivation.

    Science.gov (United States)

    Takata, Kumiko; Saito, Kazuyuki; Yasunari, Tetsuzo

    2009-06-16

    Preindustrial changes in the Asian summer monsoon climate from the 1700s to the 1850s were estimated with an atmospheric general circulation model (AGCM) using historical global land cover/use change data reconstructed for the last 300 years. Extended cultivation resulted in a decrease in monsoon rainfall over the Indian subcontinent and southeastern China and an associated weakening of the Asian summer monsoon circulation. The precipitation decrease in India was marked and was consistent with the observational changes derived from examining the Himalayan ice cores for the concurrent period. Between the 1700s and the 1850s, the anthropogenic increases in greenhouse gases and aerosols were still minor; also, no long-term trends in natural climate variations, such as those caused by the ocean, solar activity, or volcanoes, were reported. Thus, we propose that the land cover/use change was the major source of disturbances to the climate during that period. This report will set forward quantitative examination of the actual impacts of land cover/use changes on Asian monsoons, relative to the impact of greenhouse gases and aerosols, viewed in the context of global warming on the interannual, decadal, and centennial time scales.

  15. Changes in the Asian monsoon climate during 1700–1850 induced by preindustrial cultivation

    Science.gov (United States)

    Takata, Kumiko; Saito, Kazuyuki; Yasunari, Tetsuzo

    2009-01-01

    Preindustrial changes in the Asian summer monsoon climate from the 1700s to the 1850s were estimated with an atmospheric general circulation model (AGCM) using historical global land cover/use change data reconstructed for the last 300 years. Extended cultivation resulted in a decrease in monsoon rainfall over the Indian subcontinent and southeastern China and an associated weakening of the Asian summer monsoon circulation. The precipitation decrease in India was marked and was consistent with the observational changes derived from examining the Himalayan ice cores for the concurrent period. Between the 1700s and the 1850s, the anthropogenic increases in greenhouse gases and aerosols were still minor; also, no long-term trends in natural climate variations, such as those caused by the ocean, solar activity, or volcanoes, were reported. Thus, we propose that the land cover/use change was the major source of disturbances to the climate during that period. This report will set forward quantitative examination of the actual impacts of land cover/use changes on Asian monsoons, relative to the impact of greenhouse gases and aerosols, viewed in the context of global warming on the interannual, decadal, and centennial time scales. PMID:19487669

  16. Severe weather during the North American monsoon and its response to rapid urbanization and a changing global climate within the context of high resolution regional atmospheric modeling

    Science.gov (United States)

    Luong, Thang Manh

    The North American monsoon (NAM) is the principal driver of summer severe weather in the Southwest U.S. With sufficient atmospheric instability and moisture, monsoon convection initiates during daytime in the mountains and later may organize, principally into mesoscale convective systems (MCSs). Most monsoon-related severe weather occurs in association with organized convection, including microbursts, dust storms, flash flooding and lightning. The overarching theme of this dissertation research is to investigate simulation of monsoon severe weather due to organized convection within the use of regional atmospheric modeling. A commonly used cumulus parameterization scheme has been modified to better account for dynamic pressure effects, resulting in an improved representation of a simulated MCS during the North American monsoon experiment and the climatology of warm season precipitation in a long-term regional climate model simulation. The effect of urbanization on organized convection occurring in Phoenix is evaluated in model sensitivity experiments using an urban canopy model (UCM) and urban land cover compared to pre-settlement natural desert land cover. The presence of vegetation and irrigation makes Phoenix a "heat sink" in comparison to its surrounding desert, and as a result the modeled precipitation in response to urbanization decreases within the Phoenix urban area and increase on its periphery. Finally, analysis of how monsoon severe weather is changing in association with observed global climate change is considered within the context of a series of retrospectively simulated severe weather events during the period 1948-2010 in a numerical weather prediction paradigm. The individual severe weather events are identified by favorable thermodynamic conditions of instability and atmospheric moisture (precipitable water). Changes in precipitation extremes are evaluated with extreme value statistics. During the last several decades, there has been

  17. Insolation and Abrupt Climate Change Effects on the Western Pacific Maritime Monsoon

    Science.gov (United States)

    Partin, J. W.; Quinn, T. M.; Shen, C.; Cardenas, M.; Siringan, F. P.; Hori, M.; Okumura, Y.; Banner, J. L.; Lin, K.; Jiang, X.; Taylor, F. W.

    2013-12-01

    Many monsoon-sensitive paleoclimate archives capture the response of the Asian-Australian monsoon system to changes in summer insolation, as well as abrupt climate changes such as the Younger Dryas (YD). The response is commonly a direct one in Holocene and YD archives. In the case of insolation, increased summer insolation leads to increased monsoon rainfall over land, as captured in stalagmite δ18O records from Oman and China. We evaluate this direct response using maritime stalagmite records from the island of Palawan, Philippines (10 N, 119 E). The wet season in Palawan occurs over the same months (June-October) as in Oman, India and China. Therefore, we expected the Palawan stalagmite δ18O record, a proxy of rainfall, to have a similar response to changing insolation and hence, a trend of decreasing monsoon rainfall over the Holocene. However, the Holocene trend in two partially replicated stalagmite δ18O records is opposite to that expected: rainfall increases over the Holocene, despite the decrease of summer insolation over the Holocene. We interpret the Holocene trend observed at Palawan to be the result of an increase in the maritime monsoon that balances the reduction in the land monsoon; an interpretation that is consistent with previously published results from coupled ocean-atmosphere general circulation model runs. Seawater δ18O reconstructions from marine sediment cores in the western tropical Pacific contain a freshening trend over the Holocene, also supporting the hypothesis of increase maritime monsoon rainfall. The direct relationship between monsoon rainfall over land as recorded in the YD interval in Chinese stalagmite records is also observed in maritime monsoon rainfall during the YD at Palawan: both records get drier during the YD cold interval. This agreement between YD stalagmite records from China and Palawan contrasts sharply with the inverse relationship between these records over the Holocene. We further investigate the nature of

  18. Regulation of the monsoon climate by two different orbital rhythms and forcing mechanisms

    Science.gov (United States)

    Nakagawa, Takeshi; Okuda, Masaaki; Yonenobu, Hitoshi; Miyoshi, Norio; Fujiki, Toshiyuki; Gotanda, Katsuya; Tarasov, Pavel E.; Morita, Yoshimune; Takemura, Keiji; Horie, Shoji

    2008-06-01

    The East Asian monsoon is responsible for transferring hugeamounts of heat and moisture between the land and the adjacentocean. Significant changes in its capacity to do this will havedirect impacts on regional climatic gradients and global atmosphericcirculation. Determining the mechanisms that force long-termvariation in monsoon behavior is therefore important for understandingglobal climate change. Competing theories vary in the degreeof importance attached to glacial forcing, other orbital rhythms,and internal feedback mechanisms as primary drivers of change.There is, however, no convincing explanation as to why differentproxy records from closely neighboring regions are tuned todifferent orbital rhythms. Here we present quantitative climaticreconstructions for the past 450 k.y. based on a long pollenrecord from Lake Biwa in Japan. The data suggest that continentaland oceanic air mass temperatures respond predominantly to the100 k.y. orbital rhythm, whereas the land-ocean temperaturegradient and monsoon vigor oscillate mainly at the 23 k.y. insolationcycle. We suggest that the mechanisms for this behavior liein the differential response of land and ocean to solar forcing,and conclude that the 100 k.y. signal dominates monsoon intensityonly when the amplitude of solar forcing falls below a thresholdlevel.

  19. Contribution of oceanic and vegetation feedbacks to Holocene climate change in monsoonal Asia

    Directory of Open Access Journals (Sweden)

    A. Dallmeyer

    2010-04-01

    Full Text Available The impact of vegetation-atmosphere and ocean-atmosphere interactions on the mid- to late Holocene climate change as well as their synergy is studied for different parts of the Asian monsoon region, giving consideration to the large climatic and topographical heterogeneity in that area. We concentrate on temperature and precipitation changes as the main parameters describing monsoonal influenced climates. For our purpose, we analyse a set of coupled numerical experiments, performed with the comprehensive Earth system model ECHAM5/JSBACH-MPIOM under present-day and mid-Holocene (6 k orbital configurations (Otto et al., 2009b. The temperature change caused by the insolation forcing reveals an enhanced seasonal cycle, with a pronounced warming in summer (0.58 K and autumn (1.29 K and a cooling in the other seasons (spring: -1.32 K; winter: -0.97 K. Most of this change can be attributed to the direct response of the atmosphere, but the ocean, whose reaction has a lagged seasonal cycle (warming in autumn and winter, cooling in the other seasons, strongly modifies the signal. The simulated contribution of dynamic vegetation is small and most effective in winter, where it slightly warms the near-surface atmosphere (approx. 0.03 K. The temperature difference attributed to the synergy is on average positive, but also small. Concerning the precipitation, the most remarkable change is the postponement and enhancement of the Asian monsoon (0.46 mm/day in summer, 0.53 mm/day in autumn, mainly related to the direct atmospheric response. On regional average, the interactive ocean (ca. 0.18 mm/day amplifies the direct effect, but tends to weaken the East Asian summer monsoon and strongly increases the Indian summer monsoon rainfall rate (0.68 mm/day. The influence of dynamic vegetation on precipitation is comparatively small (<0.04 mm/day. The synergy effect has no influence, on average.

  20. Future of West African Monsoon in A Warming Climate

    Science.gov (United States)

    Raj, Jerry; Kunhu Bangalath, Hamza; Stenchikov, Georgiy

    2016-04-01

    West Africa is the home of more than 300 million people whose agriculture based economy highly relies on West African Monsoon (WAM), which produces a mean annual rainfall of 150 - 2,500 mm and variability and change of which have devastating impact on the local population. The observed widespread drought in West Africa during the 1970s and 1980s was the most significant drought at regional scale during the twentieth century. In this study, a high resolution AGCM, High Resolution Atmospheric Model (HiRAM), is used to study the effects of anthropogenic greenhouse warming on WAM. HiRAM is developed at GFDL based on AM2 and employs a cubed-sphere finite volume dynamical core and uses shallow convective scheme (for moist convection and stratiform cloudiness) instead of deep convective parameterization. Future projections are done using two representative concentration pathways, RCP 4.5 and RCP 8.5 from 2007 to 2050 at C360 (~25 km) resolution. Both RCP 4.5 and RCP 8.5 scenarios predict warming over West Africa during boreal summer, especially over Western Sahara. Also, both scenarios predict southward shift in WAM rainfall pattern and drying over Southern Sahara, while RCP 8.5 predicts enhanced rainfall over Gulf of Guinea. The intensification of rainfall over tropical latitudes is caused by increased low level winds due to warm SST over Gulf of Guinea.

  1. Hydrological changes of DOM composition and biodegradability of rivers in temperate monsoon climates

    Science.gov (United States)

    Shin, Yera; Lee, Eun-Ju; Jeon, Young-Joon; Hur, Jin; Oh, Neung-Hwan

    2016-09-01

    The spatial and hydrological dynamics of dissolved organic matter (DOM) composition and biodegradability were investigated for the five largest rivers in the Republic of Korea (South Korea) during the years 2012-2013 using incubation experiments and spectroscopic measurements, which included parallel factor analysis (PARAFAC). The lower reaches of the five rivers were selected as windows showing the integrated effects of basin biogeochemistry of different land use under Asian monsoon climates, providing an insight on consistency of DOM dynamics across multiple sites which could be difficult to obtain from a study on an individual river. The mean dissolved organic carbon (DOC) concentrations of the five rivers were relatively low, ranging from 1.4 to 3.4 mg L-1, due to the high slope and low percentage of wetland cover in the basin. Terrestrial humic- and fulvic-like components were dominant in all the rivers except for one, where protein-like compounds were up to ∼80%. However, terrestrial components became dominant in all five of the rivers after high precipitation during the summer monsoon season, indicating the strong role of hydrology on riverine DOM compositions for the basins under Asian monsoon climates. Considering that 64% of South Korea is forested, our results suggest that the forests could be a large source of riverine DOM, elevating the DOM loads during monsoon rainfall. Although more DOM was degraded when DOM input increased, regardless of its sources, the percent biodegradability was reduced with increased proportions of terrestrially derived aromatic compounds. The shift in DOM quality towards higher percentages of aromatic terrestrial compounds may alter the balance of the carbon cycle of coastal ecosystems by changing microbial metabolic processes if climate extremes such as heavy storms and typhoons become more frequent due to climate change.

  2. NUMERICAL SIMULATION OF INFLUENCE OF INDIAN OCEAN SSTA ON WEATHER AND CLIMATE IN ASIAN MONSOON REGION

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Sea surface temperature anomaly (SSTA) exerts great influence on the generation of global weather and climate. Much progress has been made with respect to SSTA in the Pacific Ocean region in contrast to the Indian Ocean. The IAP9L model, which is developed at the Institute of Atmospheric Physics of the Chinese Academy of Science, is used to simulate the influence of the Indian Ocean SSTA on the general circulation and weather/climate anomalies in the monsoon region of Asia. It is found that the warm (cool) SSTA in the equatorial low latitudes of the Indian Ocean triggers winter (summer) teleconnection patterns in middle and higher latitudes of the Northern Hemisphere that are similar to PNA or EAP. They play a very important role in the anomaly of circulation or weather and climate in the middle and lower latitudes of the Asian summer monsoon region. With the warm (cool) SSTA forcing in the Indian Ocean, the Asian summer monsoon sets up at a late (early) date and withdraws at a early (late) date, lasting for a short (long) duration at a weak (strong) intensity. The Indian Ocean SSTA is shown to be an indicator for precipitation variation in China.

  3. Large-scale urbanization effects on eastern Asian summer monsoon circulation and climate

    Science.gov (United States)

    Chen, Haishan; Zhang, Ye; Yu, Miao; Hua, Wenjian; Sun, Shanlei; Li, Xing; Gao, Chujie

    2016-07-01

    Impacts of large-scale urbanization over eastern China on East Asian summer monsoon circulation and climate are investigated by comparing three 25-year climate simulations with and without incorporating modified land cover maps reflecting two different idealized large-scale urbanization scenarios. The global atmospheric general circulation model CAM4.0 that includes an urban canopy parameterization scheme is employed in this study. The large-scale urbanization over eastern China leads to a significant warming over most of the expanded urban areas, characterized by an increase of 3 K for surface skin temperature, 2.25 K for surface air temperature, significant warming of both daily minimum and daily maximum air temperatures, and 0.4 K for the averaged urban-rural temperature difference. The urbanization is also accompanied by an increase in surface sensible heat flux, a decrease of the net surface shortwave and long-wave radiation, and an enhanced surface thermal heating to the atmosphere in most Eastern Asia areas. It is noted that the responses of the East Asian summer monsoon circulation exhibits an evident month-to-month variation. Across eastern China, the summer monsoon in early summer is strengthened by the large-scale urbanization, but weakened (intensified) over southern (northern) part of East Asia in late summer. Meanwhile, early summer precipitation is intensified in northern and northeastern China and suppressed in south of ~35°N, but late summer precipitation is evidently suppressed over northeast China, the Korean Peninsula and Japan with enhancements in southern China, the South China Sea, and the oceanic region south and southeast of the Taiwan Island. This study highlights the evidently distinct month-to-month responses of the monsoon system to the large-scale urbanization, which might be attributed to different basic states, internal feedbacks (cloud, rainfall) as well as a dynamic adjustment of the atmosphere. Further investigation is required

  4. The influence of land cover change in the Asian monsoon region on present-day and mid-Holocene climate

    Directory of Open Access Journals (Sweden)

    A. Dallmeyer

    2011-02-01

    Full Text Available Using the general circulation model ECHAM5/JSBACH, we investigate the biogeophysical effect of large-scale afforestation and deforestation in the Asian monsoon domain on present-day and mid-Holocene climate. We demonstrate that the applied land cover change does not only modify the local climate but also change the climate in North Africa and the Middle East via teleconnections. Deforestation in the Asian monsoon domain enhances the rainfall in North Africa. In parts of the Sahara summer precipitation is more than doubled. In contrast, afforestation strongly decreases summer rainfall in the Middle East and even leads to the cessation of the rainfall-activity in some parts of this region.

    Regarding the local climate, deforestation results in a reduction of precipitation and a cooler climate as grass mostly has a higher albedo than forests. However, in the core region of the Asian monsoon the decrease of evaporative cooling in the monsoon season overcompensates this signal and results in a net warming. Afforestation has mainly the opposite effect, although the pattern of change is less clear. It leads to more precipitation in most parts of the Asian monsoon domain and a warmer climate except for the southern regions where a stronger evaporation decreases near-surface temperatures in the monsoon season.

    When prescribing mid-Holocene insolation, the pattern of local precipitation change differs. Afforestation particularly increases monsoon rainfall in the region along the Yellow River which was the settlement area of major prehistoric cultures. In this region, the effect of land cover change on precipitation is half as large as the orbitally-induced precipitation change. Thus, our model results reveal that mid- to late-Holocene land cover change could strongly have contributed to the decreasing Asian monsoon precipitation during the Holocene known from reconstructions.

  5. The influence of land cover change in the Asian monsoon region on present-day and mid-Holocene climate

    Science.gov (United States)

    Dallmeyer, A.; Claussen, M.

    2011-06-01

    Using the general circulation model ECHAM5/JSBACH, we investigate the biogeophysical effect of large-scale afforestation and deforestation in the Asian monsoon domain on present-day and mid-Holocene climate. We demonstrate that the applied land cover change does not only modify the local climate but also change the climate in North Africa and the Middle East via teleconnections. Deforestation in the Asian monsoon domain enhances the rainfall in North Africa. In parts of the Sahara summer precipitation is more than doubled. In contrast, afforestation strongly decreases summer rainfall in the Middle East and even leads to the cessation of the rainfall-activity in some parts of this region. Regarding the local climate, deforestation results in a reduction of precipitation and a cooler climate as grass mostly has a higher albedo than forests. However, in the core region of the Asian monsoon the decrease in evaporative cooling in the monsoon season overcompensates this signal and results in a net warming. Afforestation has mainly the opposite effect, although the pattern of change is less clear. It leads to more precipitation in most parts of the Asian monsoon domain and a warmer climate except for the southern regions where a stronger evaporation decreases near-surface temperatures in the monsoon season. When prescribing mid-Holocene insolation, the pattern of local precipitation change differs. Afforestation particularly increases monsoon rainfall in the region along the Yellow River which was the settlement area of major prehistoric cultures. In this region, the effect of land cover change on precipitation is half as large as the orbitally-induced precipitation change. Thus, our model results reveal that mid- to late-Holocene land cover change could strongly have contributed to the decreasing Asian monsoon precipitation during the Holocene known from reconstructions.

  6. Indian monsoon variations during three contrasting climatic periods: the Holocene, Heinrich Stadial 2 and the last interglacial-glacial transition

    Science.gov (United States)

    Zorzi, Coralie; Fernanda Sanchez Goñi, Maria; Anupama, Krishnamurthy; Prasad, Srinivasan; Hanquiez, Vincent; Johnson, Joel; Giosan, Liviu

    2016-04-01

    In contrast to the East Asian and African monsoons the Indian monsoon is still poorly documented throughout the last climatic cycle (last 135,000 years). Pollen analysis from two marine sediment cores (NGHP-01-16A and NGHP-01-19B) collected from the offshore Godavari and Mahanadi basins, both located in the Core Monsoon Zone (CMZ) reveals changes in Indian summer monsoon variability and intensity during three contrasting climatic periods: the Holocene, the Heinrich Stadial (HS) 2 and the Marine Isotopic Stage (MIS) 5/4 during the ice sheet growth transition. During the first part of the Holocene between 11,300 and 4,200 cal years BP, characterized by high insolation (minimum precession, maximum obliquity), the maximum extension of the coastal forest and mangrove reflects high monsoon rainfall. This climatic regime contrasts with that of the second phase of the Holocene, from 4,200 cal years BP to the present, marked by the development of drier vegetation in a context of low insolation (maximum precession, minimum obliquity). The historical period in India is characterized by an alternation of strong and weak monsoon centennial phases that may reflect the Medieval Climate Anomaly and the Little Ice Age, respectively. During the HS 2, a period of low insolation and extensive iceberg discharge in the North Atlantic Ocean, vegetation was dominated by grassland and dry flora indicating pronounced aridity as the result of a weak Indian summer monsoon. The MIS 5/4 glaciation, also associated with low insolation but moderate freshwater fluxes, was characterized by a weaker reduction of the Indian summer monsoon and a decrease of seasonal contrast as recorded by the expansion of dry vegetation and the development of Artemisia, respectively. Our results support model predictions suggesting that insolation changes control the long term trend of the Indian monsoon precipitation, but its millennial scale variability and intensity are instead modulated by atmospheric

  7. Global Monsoon and Long-Term climate Changes

    Institute of Scientific and Technical Information of China (English)

    WANG Pinxian

    2009-01-01

    @@ The core in the current "Global Warming" debate is how to discriminate the anthropogenic from natural warming. To answer this question, we have to know the natural trend of climate changes, an issue on which scientists' opinions diverge incredibly. Some scientists tell us that the next ice age will not come in some 50 thousands years (Berger & Loutre, 2002), but others believe that new glaciation would have been upon us several thousands years ago, should it be not postponed by early human impact (Ruddiman, 2003). Climatologists now talking on "global warming" warned about "global cooling" over 30 years ago.

  8. Miocene climate seasonality in southern India - first direct evidence for a weak Indian monsoon during the Middle Miocene Climate Optimum

    Science.gov (United States)

    Piller, W. E.; Reuter, M.; Kern, A. K.; Harzhauser, M.

    2012-04-01

    The Asian monsoon is an integral component of the global climate system. This large-scale atmospheric circulation comprises the East Asian summer and winter monsoon and the Indian monsoon subsystems, all characterized by seasonal reversing winds and precipitation changes associated with asymmetric heating of land and sea. The Neogene monsoon history is mainly reconstructed from chemical and physical weathering rates recorded in widely continuous marine sequences of the Indus Fan, Bengal Fan and South China Sea, which, depending on the source, physiography and sediment, indicate drier or wetter climates. These indirect climate proxies display an unusually dry period during the Middle Miocene Climate Optimum (MMCO, 16.5-15 Ma). As part of the FWF-projects P18189, P21414 and P23492, we present an Early/Middle Miocene coastal palynoflora record from the siliciclastic Ambalapuzha Formation at the coastal cliff of Varkala (Kerala Basin, SW India). Pollen assemblages and facies document a coastal wetland with mangrove vegetation. The Coexistence Approach was applied for palaeoclimatic reconstructions. This method uses climatic tolerances of all nearest living relatives known for a fossil flora by assuming that the tolerances of a fossil taxon are not significantly different from its modern counterpart. The maximum overlap of the environmental tolerances of all nearest living relatives (coexistence interval) is then regarded as being indicative of the most likely palaeoenvironment. By enquiring the Palaeoflora Database (http://www.palaeoflora.de/), the palaeoclimatic parameters of the pollen flora were calculated. The reconstructed climatic parameters for the MMCO show a seasonal precipitation pattern with a dry and a wet period and moderate rainfalls during the warmest period, which is comparable to the present day annual precipitation cycle in coastal Kerala, and affirms the presence of a monsoon-like atmospheric circulation over South India during the MMCO. However, the

  9. Impact of high resolution land surface initialization in Indian summer monsoon simulation using a regional climate model

    Science.gov (United States)

    Unnikrishnan, C. K.; Rajeevan, M.; Rao, S. Vijaya Bhaskara

    2016-06-01

    The direct impact of high resolution land surface initialization on the forecast bias in a regional climate model in recent years over Indian summer monsoon region is investigated. Two sets of regional climate model simulations are performed, one with a coarse resolution land surface initial conditions and second one used a high resolution land surface data for initial condition. The results show that all monsoon years respond differently to the high resolution land surface initialization. The drought monsoon year 2009 and extended break periods were more sensitive to the high resolution land surface initialization. These results suggest that the drought monsoon year predictions can be improved with high resolution land surface initialization. Result also shows that there are differences in the response to the land surface initialization within the monsoon season. Case studies of heat wave and a monsoon depression simulation show that, the model biases were also improved with high resolution land surface initialization. These results show the need for a better land surface initialization strategy in high resolution regional models for monsoon forecasting.

  10. Assessing reliability of regional climate projections: the case of Indian monsoon.

    Science.gov (United States)

    Ramesh, K V; Goswami, Prashant

    2014-02-12

    Projections of climate change are emerging to play major roles in many applications. However, assessing reliability of climate change projections, especially at regional scales, remains a major challenge. An important question is the degree of progress made since the earlier IPCC simulations (CMIP3) to the latest, recently completed CMIP5. We consider the continental Indian monsoon as an example and apply a hierarchical approach for assessing reliability, using the accuracy in simulating the historical trend as the primary criterion. While the scope has increased in CMIP5, there is essentially no improvement in skill in projections since CMIP3 in terms of reliability (confidence). Thus, it may be necessary to consider acceptable models for specific assessment rather than simple ensemble. Analysis of climate indices shows that in both CMIP5 and CMIP3 certain common processes at large and regional scales as well as slow timescales are associated with successful simulation of trend and mean.

  11. THE CLIMATIC CHARACTERISTICS OF SUMMER MONSOON ONSET OVER THE SOUTH CHINA SEA Ⅰ40—YEAR AVERAGE

    Institute of Scientific and Technical Information of China (English)

    冯瑞权; 林建恒

    2002-01-01

    By using 40-year NCEP reanalysis daily data91958-1997),we have analyzed the climatic characteristics of summer monsoon onset in the South China Sea(1050°E-120°E,5°N-20°N,to be simplified as SCS in the text followed) pentad y pentad(5 days),According to our new definition,in the monsoon area of the SCS two of the following conditions should be satistied:1)At 850hPa,the southwest winds should be greater than 2m/s.2)At 850 hPa.θse should e greater than 335°K.The new definition means that the summermonsoon is the southwest winds high temperature and high moisture.The onset of the SCS summer monsoon is defined to start when one half of the SCS area(105°E-120°E,5°N-20°N)is controlled by the summer monsoon.The analyzed results revealed the following:1) The summer monsoon in the SCS starts to build up abruptly in the 4th pentad in May.2) The summer monsoon onset in the SCS is resulted from the development and intensification of southwesterly monsoon in the Bay of Bengal.3) The onset of the summer monsoon and establishment of the summer monsoon rainfall season in the SCS occur simultaneously.4) During the summer monsoon onset in the SCS,troughs deepen and widen quickly in the lower troposphere of the India:the subtropical high in the Western pacific moves eastward off the SCS in the middle troposphere:the easterly advances northward over the SCS in the upper troposphere.

  12. Role of the tropical Pacific Ocean in strengthening the East Asian Monsoon: Climate model study of MIS-13

    Science.gov (United States)

    Karami, M.; Herold, N.; Yin, Q.; Berger, A.

    2012-12-01

    Studying past climates is a valuable approach to improve our understanding of the present and future climate systems. Among the significant events in the history of climate, the interglacial periods are good candidates for representation of the future climate because of their astronomical characteristics and their similarity to predicted anthropogenic warming. Moreover, some interglacials exhibited significant changes in atmospheric and oceanic properties due to only small changes in their climatic forcing (greenhouse gases and solar insolation) which also make them a good case for investigating past climates. For instance, the interglacial stage of around 0.5 Ma identified as Marine Isotopic stage 13 (MIS-13), the focus of this study, was characterized by extremely strong East Asian and Indian summer monsoons while the CO2 and CH4 levels were lower and seasonal radiation energy could reach up to 50 Wm-2 higher than today. The extreme monsoon precipitation is quite unexpected for a climate with such forcing. To understand the physics-based mechanism that enhances the East Asian Summer Monsoon (EASM) during MIS-13, we used two fully coupled general circulation models, the HadCM3 and CCSM3. In MIS-13 experiments, concentrations of greenhouse gases were prescribed lower than in pre-industrial and seasonal insolation characterised by Northern-Hemisphere (NH) summer occurring at perihelion instead of aphelion as it does today. Results of both models confirm increased summer precipitation in the monsoon regions. We find that the tropical Pacific Ocean plays a major role in strengthening the EASM in MIS-13. Simulations of MIS-13 show stronger easterly surface winds along the equatorial Pacific and a subsequent increase in the mean thermocline tilt, in addition to a westward shift of the cold tongue. These changes alter the background climatic state of the equatorial Pacific towards a La Niña-type state. The interannual variability around the La Niña-like background

  13. Revised cloud processes to improve the mean and intraseasonal variability of Indian summer monsoon in climate forecast system: Part 1

    Science.gov (United States)

    Abhik, S.; Krishna, R. P. M.; Mahakur, M.; Ganai, Malay; Mukhopadhyay, P.; Dudhia, J.

    2017-06-01

    The National Centre for Environmental Prediction (NCEP) Climate Forecast System (CFS) is being used for operational monsoon prediction over the Indian region. Recent studies indicate that the moist convective process in CFS is one of the major sources of uncertainty in monsoon predictions. In this study, the existing simple cloud microphysics of CFS is replaced by the six-class Weather Research Forecasting (WRF) single moment (WSM6) microphysical scheme. Additionally, a revised convective parameterization is employed to improve the performance of the model in simulating the boreal summer mean climate and intraseasonal variability over the Indian summer monsoon (ISM) region. The revised version of the model (CFSCR) exhibits a potential to improve shortcomings in the seasonal mean precipitation distribution relative to the standard CFS (CTRL), especially over the ISM region. Consistently, notable improvements are also evident in other observed ISM characteristics. These improvements are found to be associated with a better simulation of spatial and vertical distributions of cloud hydrometeors in CFSCR. A reasonable representation of the subgrid-scale convective parameterization along with cloud hydrometeors helps to improve the convective and large-scale precipitation distribution in the model. As a consequence, the simulated low-frequency boreal summer intraseasonal oscillation (BSISO) exhibits realistic propagation and the observed northwest-southeast rainband is well reproduced in CFSCR. Additionally, both the high and low-frequency BSISOs are better captured in CFSCR. The improvement of low and high-frequency BSISOs in CFSCR is shown to be related to a realistic phase relationship of clouds.type="synopsis">type="main">Plain Language SummaryThis study attempts to demonstrate the impact of better representation of cloud processes on simulating the mean and intraseasonal variability of Indian summer monsoon in a revised version of CFSv2 called CFSCR. The CFSCR shows

  14. Projected hydrologic changes in monsoon-dominated Himalaya Mountain basins with changing climate and deforestation

    Science.gov (United States)

    Neupane, Ram P.; White, Joseph D.; Alexander, Sara E.

    2015-06-01

    In mountain headwaters, climate and land use changes affect short and long term site water budgets with resultant impacts on landslide risk, hydropower generation, and sustainable agriculture. To project hydrologic change associated with climate and land use changes in the Himalaya Mountains, we used the Soil and Water Assessment Tool (SWAT) calibrated for the Tamor and Seti River basins located at eastern and western margins of Nepal. Future climate change was modeled using averaged temperature and precipitation for 2080 derived from Special Report on Emission Scenarios (SRES) (B1, A1B and A2) of 16 global circulation models (GCMs). Land use change was modeled spatially and included expansion of (1) agricultural land, (2) grassland, and (3) human settlement area that were produced by considering existing land use with projected changes associated with viability of elevation and slope characteristics of the basins capable of supporting different land use type. From these simulations, higher annual stream discharge was found for all GCM-derived scenarios compared to a baseline simulation with maximum increases of 13 and 8% in SRES-A2 and SRES-A1B for the Tamor and Seti basins, respectively. On seasonal basis, we assessed higher precipitation during monsoon season in all scenarios that corresponded with higher stream discharge of 72 and 68% for Tamor and Seti basins, respectively. This effect appears to be geographically important with higher influence in the eastern Tamor basin potentially due to longer and stronger monsoonal period of that region. However, we projected minimal changes in stream discharge for the land use scenarios potentially due to higher water transmission to groundwater reservoirs associated with fractures of the Himalaya Mountains rather than changes in surface runoff. However, when combined the effects of climate and land use changes, discharge was moderately increased indicating counteracting mechanisms of hydrologic yield in these mountains

  15. Intraseasonal Variability of the Indian Summer Monsoon in the Regional Climate Model COSMO-CLM

    Science.gov (United States)

    Befort, Daniel J.; Leckebusch, Gregor C.; Cubasch, Ulrich

    2015-04-01

    The regional climate model COSMO-CLM driven by ERA-Interim reanalysis data with a spatial resolution of 55km is used to simulate observed features of the intraseasonal variability of the Indian summer monsoon (ISM) during the period 1979 until 2011. One of these features is the northward propagation of the monsoon intraseasonal oscillations. We find, that the temporal evolution of this oscillation between model and observation is in good agreement, but the strength is less well simulated. Additionally, the models capability to simulate observed dry and wet events on a weekly time scale is investigated using the standardized precipitation index. In general, the model is capable to simulate these events with a similar magnitude at the same time, but we find a higher ability for dry compared to wet events. We hypothesize this is related to differences in the atmospheric circulation during dry and wet events. Analyses show, that dry events are characterized by a cyclonic vortex over India as well as an anti-cyclonic vortex over Pakistan region in 500hPa, whereas wet events are characterized by an anti-cyclonic vortex over India, only. It is found that COSMO-CLM has a higher ability to simulate the observed anomalous circulation over Pakistan region compared to observed anomalous circulation patterns over India. Overall, this study shows that the current configuration of COSMO-CLM is able to simulate key features of the intraseasonal variability of the Indian summer monsoon. Thus, under consideration of its limitations, COSMO-CLM is suitable to investigate possible changes of the intraseasonal variability of ISM under changed climate conditions.

  16. Temporal derivative of Total Solar Irradiance and anomalous Indian summer monsoon: An empirical evidence for a Sun–climate connection

    Digital Repository Service at National Institute of Oceanography (India)

    Agnihotri, R.; Dutta, K.; Soon, W.

    timescale. & 2011 Elsevier Ltd. All rights reserved. populated countries of of the global climate (Khandekar, 2010 to global warm- inconsistencies have acts as a key player in governing decadal to millennial scale climate variation (Verschuren et al., 2000....D., Murray, D.W., 2004. A solar (irradiance) trigger for millennial-scale abrupt changes in the southwest monsoon. Paleoceanography 19, PA3015. doi:10.1029/2004PA001031. Hiremath, K.M., Mandi, P.I., 2004. Influence of the solar activity on the Indian monsoon...

  17. Late quaternary climate, precipitation δ18O, and Indian monsoon variations over the Tibetan Plateau

    Science.gov (United States)

    Li, Jingmin; Ehlers, Todd A.; Werner, Martin; Mutz, Sebastian G.; Steger, Christian; Paeth, Heiko

    2017-01-01

    The Himalaya-Tibet orogen contains one of the largest modern topographic and climate gradients on Earth. Proxy data from the region provide a basis for understanding Tibetan Plateau paleo climate and paleo elevation reconstructions. Paleo climate model comparisons to proxy data compliment sparsely located data and can improve climate reconstructions. This study investigates temporal changes in precipitation, temperature and precipitation δ18O (δO18p) over the Himalaya-Tibet from the Last Glacial Maximum (LGM) to present. We conduct a series of atmospheric General Circulation Model (GCM, ECHAM5-wiso) experiments at discrete time slices including a Pre-industrial (PI, Pre-1850 AD), Mid Holocene (MH, 6 ka BP) and LGM (21 ka BP) simulations. Model predictions are compared with existing proxy records. Model results show muted climate changes across the plateau during the MH and larger changes occurring during the LGM. During the LGM surface temperatures are ∼ 2.0- 4.0 °C lower across the Himalaya and Tibet, and >5.0 °C lower at the northwest and northeast edge of the Tibetan Plateau. LGM mean annual precipitation is 200-600 mm/yr lower over on the Tibetan Plateau. Model and proxy data comparison shows a good agreement for the LGM, but large differences for the MH. Large differences are also present between MH proxy studies near each other. The precipitation weighted annual mean δ18Op lapse rate at the Himalaya is about 0.4 ‰ /km larger during the MH and 0.2 ‰ /km smaller during the LGM than during the PI. Finally, rainfall associated with the continental Indian monsoon (between 70°E-110°E and 10°N-30°N) is about 44% less in the LGM than during PI times. The LGM monsoon period is about one month shorter than in PI times. Taken together, these results document significant spatial and temporal changes in temperature, precipitation, and δ18Op over the last ∼21 ka. These changes are large enough to impact interpretations of proxy data and the intensity of

  18. Simulation skill of APCC set of global climate models for Asian summer monsoon rainfall variability

    Science.gov (United States)

    Singh, U. K.; Singh, G. P.; Singh, Vikas

    2015-04-01

    The performance of 11 Asia-Pacific Economic Cooperation Climate Center (APCC) global climate models (coupled and uncoupled both) in simulating the seasonal summer (June-August) monsoon rainfall variability over Asia (especially over India and East Asia) has been evaluated in detail using hind-cast data (3 months advance) generated from APCC which provides the regional climate information product services based on multi-model ensemble dynamical seasonal prediction systems. The skill of each global climate model over Asia was tested separately in detail for the period of 21 years (1983-2003), and simulated Asian summer monsoon rainfall (ASMR) has been verified using various statistical measures for Indian and East Asian land masses separately. The analysis found a large variation in spatial ASMR simulated with uncoupled model compared to coupled models (like Predictive Ocean Atmosphere Model for Australia, National Centers for Environmental Prediction and Japan Meteorological Agency). The simulated ASMR in coupled model was closer to Climate Prediction Centre Merged Analysis of Precipitation (CMAP) compared to uncoupled models although the amount of ASMR was underestimated in both models. Analysis also found a high spread in simulated ASMR among the ensemble members (suggesting that the model's performance is highly dependent on its initial conditions). The correlation analysis between sea surface temperature (SST) and ASMR shows that that the coupled models are strongly associated with ASMR compared to the uncoupled models (suggesting that air-sea interaction is well cared in coupled models). The analysis of rainfall using various statistical measures suggests that the multi-model ensemble (MME) performed better compared to individual model and also separate study indicate that Indian and East Asian land masses are more useful compared to Asia monsoon rainfall as a whole. The results of various statistical measures like skill of multi-model ensemble, large spread

  19. Middle Miocene pedological record of monsoonal climate from NW Himalaya (Jammu & Kashmir State), India

    Science.gov (United States)

    Ganjoo, R. K.; Shaker, Som

    2007-03-01

    The Lower Siwalik Subgroup represented by the Dodenal (Kamlial Formation) and Ramnagar Members (Chinji Formation) is well exposed at Ramnagar, District Udhampur, Jammu & Kashmir State. The Ramnagar Member consists of an alternating sequence of silt and mudstone formed under crevasse-splay and flood-plain environments of deposition. Argillisol and gleysol soils are developed on the Ramnagar Member deposits. Argillisols formed under well-drained conditions at high levels, whereas gleysols formed under poorly drained conditions at low levels of the palaeo-landscape. Geochemical and micromorphological studies of the Ramnagar Member palaeosols suggest formation under wet and humid climatic conditions. Early uplift of the Tibetan Plateau/Himalaya resulted in a contemporaneous change in precipitation and monsoonal climate conditions within the Indian region beginning in Middle Miocene.

  20. Winter climate changes over East Asian region under RCP scenarios using East Asian winter monsoon indices

    Science.gov (United States)

    Hong, Ja-Young; Ahn, Joong-Bae; Jhun, Jong-Ghap

    2017-01-01

    The changes in the winter climatology and variability of the East Asian winter monsoon (EAWM) for the late 21st century (2070-2099) under the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios are projected in terms of EAWM indices (EAWMIs). Firstly, the capability of the climate models participating in the Coupled Model Intercomparison Project phase 5 (CMIP5) in simulating the boreal winter climatology and the interannual variability of the EAWM for the late 20th century (1971-2000) is examined. Nine of twenty-three climate models are selected based on the pattern correlations with observation and a multi-model ensemble is applied to the nine model data. Three of twelve EAWMIs that show the most significant temporal correlations between the observation and CMIP5 surface air temperatures are utilized. The ensemble CMIP5 is capable of reproducing the overall features of the EAWM in spite of some biases in the region. The negative correlations between the EAWMIs and boreal winter temperature are well reproduced and 3-5 years of the major interannual variation observed in this region are also well simulated according to power spectral analyses of the simulated indices. The fields regressed onto the indices that resemble the composite strong winter monsoon pattern are simulated more or less weakly in CMIP5 compared to the observation. However, the regressed fields of sea level pressure, surface air temperature, 500-hPa geopotential height, and 300-hPa zonal wind are well established with pattern correlations above 0.83 between CMIP5 and observation data. The differences between RCPs and Historical indicate strong warming, which increases with latitude, ranging from 1 to 5 °C under RCP4.5 and from 3 to 7 °C under RCP8.5 in the East Asian region. The anomalous southerly winds generally become stronger, implying weaker EAWMs in both scenarios. These features are also identified with fields regressed onto the indices in RCPs. The future projections reveal

  1. Winter climate changes over East Asian region under RCP scenarios using East Asian winter monsoon indices

    Science.gov (United States)

    Hong, Ja-Young; Ahn, Joong-Bae; Jhun, Jong-Ghap

    2016-03-01

    The changes in the winter climatology and variability of the East Asian winter monsoon (EAWM) for the late 21st century (2070-2099) under the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios are projected in terms of EAWM indices (EAWMIs). Firstly, the capability of the climate models participating in the Coupled Model Intercomparison Project phase 5 (CMIP5) in simulating the boreal winter climatology and the interannual variability of the EAWM for the late 20th century (1971-2000) is examined. Nine of twenty-three climate models are selected based on the pattern correlations with observation and a multi-model ensemble is applied to the nine model data. Three of twelve EAWMIs that show the most significant temporal correlations between the observation and CMIP5 surface air temperatures are utilized. The ensemble CMIP5 is capable of reproducing the overall features of the EAWM in spite of some biases in the region. The negative correlations between the EAWMIs and boreal winter temperature are well reproduced and 3-5 years of the major interannual variation observed in this region are also well simulated according to power spectral analyses of the simulated indices. The fields regressed onto the indices that resemble the composite strong winter monsoon pattern are simulated more or less weakly in CMIP5 compared to the observation. However, the regressed fields of sea level pressure, surface air temperature, 500-hPa geopotential height, and 300-hPa zonal wind are well established with pattern correlations above 0.83 between CMIP5 and observation data. The differences between RCPs and Historical indicate strong warming, which increases with latitude, ranging from 1 to 5 °C under RCP4.5 and from 3 to 7 °C under RCP8.5 in the East Asian region. The anomalous southerly winds generally become stronger, implying weaker EAWMs in both scenarios. These features are also identified with fields regressed onto the indices in RCPs. The future projections reveal

  2. Post-Pliocene establishment of the present monsoonal climate in SW China: evidence from the late Pliocene Longmen megaflora

    Science.gov (United States)

    Su, T.; Jacques, F. M. B.; Spicer, R. A.; Liu, Y.-S.; Huang, Y.-J.; Xing, Y.-W.; Zhou, Z.-K.

    2013-08-01

    The paleoclimate of the late Pliocene Longmen flora from Yongping County located at the southeastern boundary of the Qinghai-Tibet Plateau was reconstructed using two leaf-physiognomy-based methods, i.e., leaf margin analysis (LMA) and Climate Leaf Analysis Multivariate Program (CLAMP), to understand the paleoclimate condition and geographical pattern of monsoonal climate in southwestern China during the late Pliocene. The mean annual temperatures (MATs) estimated by LMA and CLAMP are 17.4 ± 3.3 °C and 17.4 ± 1.3 °C, respectively, compared with 15.9 °C at present. Meanwhile, the growing season precipitation (GSP) estimated by CLAMP is 1735.5 ± 217.7 mm in the Longmen flora, compared with 986.9 mm nowadays. The calculated monsoon intensity index (MSI) of the Longmen flora is significantly lower than that of today. These results appear consistent with previous studies on the late Pliocene floras in western Yunnan based on the coexistence approach (CA), and further suggest that there was a slightly warmer and much wetter climate during the late Pliocene than the present climate in western Yunnan. We conclude that the significant change of the monsoonal climate might have been resulted from the continuous uplift of mountains in western Yunnan, as well as the intensification of the eastern Asian winter monsoon, both occurring concurrently in the post-Pliocene period.

  3. Post-Pliocene establishment of the present monsoonal climate in SW China: evidence from the late Pliocene Longmen megaflora

    Directory of Open Access Journals (Sweden)

    T. Su

    2013-04-01

    Full Text Available The paleoclimate of the late Pliocene Longmen flora from Yongping County located at the southeastern boundary of the Qinghai-Tibet Plateau was reconstructed using two leaf physiognomy based methods, i.e. Leaf Margin Analysis (LMA and Climate Leaf Analysis Multivariate Program (CLAMP, to understand the paleoclimate condition and geographical pattern of monsoonal climate in southwestern China during the late Pliocene. The mean annual temperatures (MATs estimated by LMA and CLAMP are 17.4 ± 3.3 °C and 17.4 ± 1.3 °C, respectively, compared with 15.9 °C at present. Meanwhile, the growing season precipitation (GSP estimated by CLAMP is 1735.5 ± 217.7 mm in the Longmen flora, compared with 986.9 mm nowadays. The calculated monsoon index (MSI of the Longmen flora is significantly lower than that of today. These results appear consistent with previous studies based on the coexistence approach (CA, and further suggest that there was a slightly warmer and much wetter climate during the late Pliocene than the present climate in western Yunnan. We conclude that the significant change of the monsoonal climate might have been resulted from the continuous uplift of mountains in western Yunnan, as well as the intensification of eastern Asian winter monsoon, both occurring concurrently in the post-Pliocene period.

  4. Performance evaluation of regional climate model to simulate sub-seasonal variability of Indian Summer Monsoon

    Science.gov (United States)

    Umakanth, U.; Kesarkar, Amit P.

    2017-07-01

    The study aims to evaluate the regional climate model (RegCM) over South Asian (SA) CORDEX domain to represent seasonal and sub-seasonal variability of Indian Summer Monsoon (ISM). The model's ability is evaluated by conducting two sets of experiments using one-tier approach of coupling the RegCM with a simple mixed-layer slab ocean model (SOM) and the two-tier approach of prescribing sea surface temperature (SST) to RegCM. Two model experiments are initialized at 1st January 2000 for a period of 13 year continuous simulation at a spatial resolution of 50 km. It is found that, one-tier approach realistically represents the spatial distribution of precipitation with significant improvement noticed over central India (CI) and head Bay of Bengal (BoB) regions. In addition, it also fairly reproduced the observed mean meridional circulation response to the diabatic heating produced during ISM. Most importantly, in one-tier approach the model could able to represent the observed SST and precipitation (P) relationship with significant improvement in correlation and model response time. An important result is the representation of northwest-southeast tilt of precipitation anomalies during active/break phase of monsoon. Additionally, the lagged response of vertical profiles of specific humidity, omega, vorticity and divergence over CI with respect to peak rainfall anomaly (active phase) are relatively better represented in one-tier approach. In brief, coupling improves the performance of RegCM in simulating the space-time characteristics of monsoon ISO mode.

  5. Sediment concentration rating curves for a monsoonal climate: upper Blue Nile

    Science.gov (United States)

    Moges, Mamaru A.; Zemale, Fasikaw A.; Alemu, Muluken L.; Ayele, Getaneh K.; Dagnew, Dessalegn C.; Tilahun, Seifu A.; Steenhuis, Tammo S.

    2016-07-01

    Information on sediment concentration in rivers is important for design of reservoirs and for environmental applications. Because of the scarcity of continuous sediment data, methods have been developed to predict sediment loads based on few discontinuous measurements. Traditionally, loads are being predicted using rating curves that relate sediment load to discharge. The relationship assumes inherently a unique relationship between concentration and discharge and therefore although performing satisfactorily in predicting loads, it may be less suitable for predicting concentration. This is especially true in the Blue Nile Basin of Ethiopia where concentrations decrease for a given discharge with the progression of the rainy monsoon phase. The objective of this paper is to improve the sediment concentration predictions throughout the monsoon period for the Ethiopian highlands with a modified rating type equation. To capture the observed sediment concentration pattern, we assume that the sediment concentration was at the transport limit early in the rainy season and then decreases linearly with effective rainfall towards source-limited concentration. The modified concentration rating curve was calibrated for the four main rivers in the Lake Tana basin where sediment concentrations affect fish production and tourism. Then the scalability of the rating type equation was checked in three 100 ha watersheds for which historic data were available. The results show that for predicting sediment concentrations, the (modified) concentration rating curve was more accurate than the (standard) load rating curve as expected. In addition loads were predicted more accurately for three of the four rivers. We expect that after more extensive testing over a wider geographical area, the proposed concentration rating curve will offer improved predictions of sediment concentrations in monsoonal climates.

  6. The West African monsoon: Contribution of the AMMA multidisciplinary programme to the study of a regional climate system.

    Science.gov (United States)

    Lebel, T.; Janicot, S.; Redelsperger, J. L.; Parker, D. J.; Thorncroft, C. D.

    2015-12-01

    The AMMA international project aims at improving our knowledge and understanding of the West African monsoon and its variability with an emphasis on daily-to-interannual timescales. AMMA is motivated by an interest in fundamental scientific issues and by the societal need for improved prediction of the WAM and its impacts on water resources, health and food security for West African nations. The West African monsoon (WAM) has a distinctive annual cycle in rainfall that remains a challenge to understand and predict. The location of peak rainfall, which resides in the Northern Hemisphere throughout the year, moves from the ocean to the land in boreal spring. Around the end of June there is a rapid shift in the location of peak rainfall between the coast and around 10°N where it remains until about the end of August. In September the peak rainfall returns equatorward at a relatively steady pace and is located over the ocean again by November. The fact that the peak rainfall migrates irregularly compared to the peak solar heating is due to the interactions that occur between the land, the atmosphere and the ocean. To gain a better understanding of this complex climate system, a large international research programme was launched in 2002, the biggest of its kind into environment and climate ever attempted in Africa. AMMA has involved a comprehensive field experiment bringing together ocean, land and atmospheric measurements, on timescales ranging from hourly and daily variability up to the changes in seasonal activity over a number of years. This presentation will focus on the description of the field programme and its accomplishments, and address some key questions that have been recently identified to form the core of AMMA-Phase 2.

  7. Climate implications of major geochemical elements in the Holocene sediments of the North and East China monsoonal regions

    Institute of Scientific and Technical Information of China (English)

    Qianli SUN; Zhanghua WANG; Jing CHEN; Wu FENG

    2009-01-01

    Two Holocene sediment cores were retrieved respectively from the enclosed Lake Daihai in the monsoon/arid transition zone of North China and the Taihu Lake coast in the monsoonal area of the Yangtze delta, Eastern China. Distribution of major geochemical elements and their ratios were employed to reveal the characteristics of Holocene climate and associated envir-onmental implications in the two regions. It is suggested that the temporal distribution of major elements serve as a useful indicator to denote the variations of monsoon effective precipitation for the enclosed lake area. High values of resistant elements such as Al2O3, SiO2, TiO2, (FeO + Fe2O3), MnO in the lake sediments correspond to the depressed chemical weathering and weakened mon-soon effective precipitation, while the highs of mobile and easy soluble elements such as MgO, CaO, Na2O reflect the enhanced chemical weathering and increased monsoon effective precipitation in the lake basin. In comparison, the behaviors of the major elements in sediments of the Taihu Lake coast were largely controlled by the changes both in sea transgression in the different Holocene time periods and the monsoon precipitation. The relatively highs of Al2O3, TiO2, (FeO + Fe2O3), in marine-influenced sedi-ments suggest relatively strong coastal hydrodynamics and chemical weathering, and vice versa. Meanwhile, the lows of SiO2, Na2O and CaO in the non-marine-influenced sediments also denote relatively strong hydrodynamics and chemical weathering due to enhanced monsoon precipita-tion, and vice versa. Sedimentary environment should be taken into account when achieving a full understanding of their climate implications.

  8. Heterodynes dominate precipitation isotopes in the East Asian monsoon region, reflecting interaction of multiple climate factors

    Science.gov (United States)

    Thomas, Elizabeth K.; Clemens, Steven C.; Sun, Youbin; Prell, Warren L.; Huang, Yongsong; Gao, Li; Loomis, Shannon; Chen, Guangshan; Liu, Zhengyu

    2016-12-01

    For the past decade, East Asian monsoon history has been interpreted in the context of an exceptionally well-dated, high-resolution composite record of speleothem oxygen isotopes (δ18Ocave) from the Yangtze River Valley. This record is characterized by a unique spectral response, with variance concentrated predominantly within the precession band and an enigmatic lack of variance at the eccentricity and obliquity bands. Here we examine the spectral characteristics of all existing >250-kyr-long terrestrial water isotope records in Asia, including a new water isotope record using leaf wax hydrogen isotope ratios from the Chinese Loess Plateau. There exist profound differences in spectral characteristics among all orbital-scale Asian water isotope records. We demonstrate that these differences result from latitudinal gradients in the influence of the winter and summer monsoons, both of which impact climate and water isotopes throughout East Asia. Water isotope records therefore do not reflect precipitation during a single season or from a single circulation system. Rather, water isotope records in East Asia reflect the complex interplay of oceanic and continental moisture sources, operating at multiple Earth-orbital periods. These non-linear interactions are reflected in water isotope spectra by the presence of heterodynes. Although complex, we submit that water isotope records, when paired with rapidly developing isotope-enabled model simulations, will have the potential to elucidate mechanisms causing seasonal precipitation variability and moisture source variability in East Asia.

  9. Representation of the West African Monsoon System in the aerosol-climate model ECHAM6-HAM2

    Science.gov (United States)

    Stanelle, Tanja; Lohmann, Ulrike; Bey, Isabelle

    2017-04-01

    The West African Monsoon (WAM) is a major component of the global monsoon system. The temperature contrast between the Saharan land surface in the North and the sea surface temperature in the South dominates the WAM formation. The West African region receives most of its precipitation during the monsoon season between end of June and September. Therefore the existence of the monsoon is of major social and economic importance. We discuss the ability of the climate model ECHAM6 as well as the coupled aerosol climate model ECHAM6-HAM2 to simulate the major features of the WAM system. The north-south temperature gradient is reproduced by both model versions but all model versions fail in reproducing the precipitation amount south of 10° N. A special focus is on the representation of the nocturnal low level jet (NLLJ) and the corresponding enhancement of low level clouds (LLC) at the Guinea Coast, which are a crucial factor for the regional energy budget. Most global climate models have difficulties to represent these features. The pure climate model ECHAM6 is able to simulate the existence of the NLLJ and LLC, but the model does not represent the pronounced diurnal cycle. Overall, the representation of LLC is worse in the coupled model. We discuss the model behaviors on the basis of outputted temperature and humidity tendencies and try to identify potential processes responsible for the model deficiencies.

  10. A climate model study of an intense Asian Monsoon in a La Niña-like climate of MIS-13

    Science.gov (United States)

    Karami, M. P.; Berger, A.; Herold, N.; Yin, Q. Z.

    2012-04-01

    Studying the paleo-monsoon during past interglacials is a valuable approach to improve our understanding of the monsoon system in present-day and future climates. We focus on Marine Isotopic stage 13 (MIS-13; ~0.5 Ma) which was a relatively cool interglacial, but with a paradoxically intense monsoonal precipitation over eastern and southern Asia. Our main goal is to understand the physics-based mechanism driving the intense monsoon, specifically the East Asian Summer Monsoon (EASM), during MIS-13. We applied both an intermediate complexity model (LOVECLIM) as well as fully coupled general circulation models (HadCM3 and CCSM3) to simulate pre-industrial and MIS-13 climates. The boundary conditions for MIS-13 were chosen for 506 ka with Northern-Hemisphere (NH) summer at perihelion and a CO2 concentration of 240 ppm. For pre-industrial, NH-winter occurring at perihelion and a CO2 concentration of 280 ppm were prescribed. Preliminary analysis of the model results shows different atmospheric and oceanic features in MIS-13 compared to the pre-industrial which could affect the EASM. The Northern Pacific Subtropical High (NPSH), which is an important factor in controlling the EASM, strengthened and extended to the northwest in MIS-13 partially due to cooling of the central Pacific Ocean. This in turn brought more moisture from the Central Pacific to the EASM-region and caused a northwestward shift and bending of the low-level jet along East Asia. The change in the low-level jet subsequently increased the meridional wind velocity at 850 mbar in the EASM-region providing more moisture from the tropical Pacific and Indian Oceans. In addition, higher sea-surface temperature in the Indian Ocean during MIS-13 further increased the source of moisture for the EASM. The Asian low, which is another component of the EASM-system, also shifted eastward moving the rain band northward. Moreover, it was found that MIS-13 had a dominant La Niña condition in the tropical Pacific. La Ni

  11. Twenty-first century projected summer mean climate in the Mediterranean interpreted through the monsoon-desert mechanism

    Science.gov (United States)

    Cherchi, Annalisa; Annamalai, H.; Masina, Simona; Navarra, Antonio; Alessandri, Andrea

    2016-10-01

    The term "monsoon-desert mechanism" indicates the relationship between the diabatic heating associated with the South Asian summer monsoon rainfall and the remote response in the western sub-tropics where long Rossby waves anchor strong descent with high subsidence. In CMIP5 twenty-first century climate scenarios, the precipitation over South Asia is projected to increase. This study investigates how this change could affect the summer climate projections in the Mediterranean region. In a linear framework the monsoon-desert mechanism in the context of climate change would imply that the change in subsidence over the Mediterranean should be strongly linked with the changes in South Asian monsoon precipitation. The steady-state solution from a linear model forced with CMIP5 model projected precipitation change over South Asia shows a broad region of descent in the Mediterranean, while the results from CMIP5 projections differ having increased descent mostly in the western sector but also decreased descent in parts of the eastern sector. Local changes in circulation, particularly the meridional wind, promote cold air advection that anchors the descent but the barotropic Rossby wave nature of the wind anomalies consisting of alternating northerlies/southerlies favors alternating descent/ascent locations. In fact, the local mid-tropospheric meridional wind changes have the strongest correlation with the regions where the difference in subsidence is largest. There decreased rainfall is mostly balanced by changes in moisture, omega and in the horizontal advection of moisture.

  12. Impact of modified soil thermal characteristic on the simulated monsoon climate over south Asia

    Indian Academy of Sciences (India)

    Pankaj Kumar; Ralf Podzun; Stefan Hagemann; Daniela Jacob

    2014-02-01

    In the present study, the influence of soil thermal characteristics (STC) on the simulated monsoon climate over south Asia is analyzed. The study was motivated by a common warm temperature bias over the plains of northern India that has been noticed in several global and regional climate models. To address this warm bias and its relation to STC, two sensitivity experiments have been performed with the regional climate model REMO of the Max Planck Institute for Meteorology. The control experiment uses the standard soil thermal characteristic of the model that corresponds to a moist soil. The second experiment uses modified STC that characterize a dry soil, which is more representative of the considered region, as a large part of the region has arid, semi-arid or subtropical summer wet conditions. Both experiments were conducted over 20 years using re-analysis data as lateral boundary conditions. Results show that using the modified STC the predominant regional warm bias has reduced substantially, leading to a better and more realistic surface temperature compared to observations over south Asia. Although, the magnitude of bias has reduced, the warm bias still exists over the region suggesting that other atmospheric and land surface processes also play a role, such as aerosols and irrigation. These need to be addressed adequately in future modeling studies over the region.

  13. The West African Monsoon simulated by global and regional climate models

    Science.gov (United States)

    Nikulin, Grigory; Jones, Colin; Kjellström, Erik; Gbobaniyi, Emiola

    2013-04-01

    We present results from two ensembles of global and regional climate simulations with a focus on the West African Monsoon (WAM). The first ensemble includes eight coupled atmosphere ocean general circulation models (AOGCMs) from the CMIP5 project, namely: CanESM2, CNRM-CM5, HadGEM2-ES, NorESM1-M, EC-EARTH, MIROC5, GFDL-ESM2M and MPI-ESM-LR. The second ensemble consists of corresponding downscaling of all 8 AOGCMs by a regional climate model - RCA4 produced at the Rossby Centre (SMHI) in the Africa-CORDEX activities. Spatial resolution varies from about 1° to 3° in the AOGCM ensemble while all regional simulations are at the same 0.44° resolution. To see what added value higher resolution can provide ability of the eight AOGCMs and the downscaled RCA4(AOGCMs) to simulate the key characteristics of the WAM rainy season are evaluated and then inter-compared between the global and regional ensembles. The main focus in our analysis is on the WAM rainy season onset, cessation, length, total precipitation, its mean intensity and intraseasonal variability. Future climate projections under the RCP45 and RCP85 scenarios are analyzed and again inter-compared for both ensembles in order to assess uncertainties in the future projections of the WAM rainy season from the global and regional ensembles.

  14. Evaluation of MODIS Vegetation Products in Regions of Complex Terrain and Monsoon Climates

    Science.gov (United States)

    Gebremichael, M.; Barros, A. P.

    2004-12-01

    An evaluation of the Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation products through comparison against independent surface observations is essential to establish quantitative measures of uncertainty and the confidence level of these satellite-based products for use in land-data assimilation models, for land-use change detection and attribution studies, and for process oriented research. Here, we focus specifically on Photosynthesis and Primary Productivity, Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR), Land Surface Temperature and Emissivity, and Evapotranspiration data sets. Our objective is to perform extensive quantitative assessment of the accuracy and statistical properties of these products against independent estimates in tropical mountainous regions at two climatologically distinct sites. The first site, the Sonora river basin in northern Mexico, is a semi-arid region characterized by complex topography and highly heterogeneous vegetation cover, which exhibits dramatic and fast response to rainfall forcing at the onset of the North-American Monsoon. The second site, the Marsyandi river basin in central Nepal, is a humid region characterized by strong ecohydrological gradients on steep orography, which remain generally stable subsequent to the onset of the Indian Monsoon. Atmospheric soundings, flux tower measurements, and raingauge observations are available for both sites. We evaluate the MODIS products in two ways: 1) comparison with tower-based observations, and 2) evaluation of hydrological response and diurnal cycles of surface water and energy budgets prior, during and post monsoon onset as simulated by a 3D hydroecological model with assimilation of MODIS data. Statistical analysis of the scaling behavior of the variables, both in space and time, is also performed to address the scale discrepancy between flux tower observations and the resolution of MODIS data.

  15. Representation of monsoon intraseasonal oscillations in regional climate model: sensitivity to convective physics

    KAUST Repository

    Umakanth, U.

    2015-11-07

    The aim of the study is to evaluate the performance of regional climate model (RegCM) version 4.4 over south Asian CORDEX domain to simulate seasonal mean and monsoon intraseasonal oscillations (MISOs) during Indian summer monsoon. Three combinations of Grell (G) and Emanuel (E) cumulus schemes namely, RegCM-EG, RegCM-EE and RegCM-GE have been used. The model is initialized at 1st January, 2000 for a 13-year continuous simulation at a spatial resolution of 50 km. The models reasonably simulate the seasonal mean low level wind pattern though they differ in simulating mean precipitation pattern. All models produce dry bias in precipitation over Indian land region except in RegCM-EG where relatively low value of dry bias is observed. On seasonal scale, the performance of RegCM-EG is more close to observation though it fails at intraseasonal time scales. In wave number-frequency spectrum, the observed peak in zonal wind (850 hPa) at 40–50 day scale is captured by all models with a slight change in amplitude, however, the 40–50 day peak in precipitation is completely absent in RegCM-EG. The space–time characteristics of MISOs are well captured by RegCM-EE over RegCM-GE, however it fails to show the eastward propagation of the convection across the Maritime Continent. Except RegCM-EE all other models completely underestimates the moisture advection from Equatorial Indian Ocean onto Indian land region during life-cycle of MISOs. The characteristics of MISOs are studied for strong (SM) and weak (WM) monsoon years and the differences in model performances are analyzed. The wavelet spectrum of rainfall over central India denotes that, the SM years are dominated by high frequency oscillations (period <20 days) whereas little higher periods (>30 days) along with dominated low periods (<20 days) observed during WM years. During SM, RegCM-EE is dominated with high frequency oscillations (period <20 days) whereas in WM, RegCM-EE is dominated with periods >20

  16. Representation of monsoon intraseasonal oscillations in regional climate model: sensitivity to convective physics

    Science.gov (United States)

    Umakanth, U.; Kesarkar, Amit P.; Raju, Attada; Vijaya Bhaskar Rao, S.

    2016-08-01

    The aim of the study is to evaluate the performance of regional climate model (RegCM) version 4.4 over south Asian CORDEX domain to simulate seasonal mean and monsoon intraseasonal oscillations (MISOs) during Indian summer monsoon. Three combinations of Grell (G) and Emanuel (E) cumulus schemes namely, RegCM-EG, RegCM-EE and RegCM-GE have been used. The model is initialized at 1st January, 2000 for a 13-year continuous simulation at a spatial resolution of 50 km. The models reasonably simulate the seasonal mean low level wind pattern though they differ in simulating mean precipitation pattern. All models produce dry bias in precipitation over Indian land region except in RegCM-EG where relatively low value of dry bias is observed. On seasonal scale, the performance of RegCM-EG is more close to observation though it fails at intraseasonal time scales. In wave number-frequency spectrum, the observed peak in zonal wind (850 hPa) at 40-50 day scale is captured by all models with a slight change in amplitude, however, the 40-50 day peak in precipitation is completely absent in RegCM-EG. The space-time characteristics of MISOs are well captured by RegCM-EE over RegCM-GE, however it fails to show the eastward propagation of the convection across the Maritime Continent. Except RegCM-EE all other models completely underestimates the moisture advection from Equatorial Indian Ocean onto Indian land region during life-cycle of MISOs. The characteristics of MISOs are studied for strong (SM) and weak (WM) monsoon years and the differences in model performances are analyzed. The wavelet spectrum of rainfall over central India denotes that, the SM years are dominated by high frequency oscillations (period 30 days) along with dominated low periods (20 days. Except RegCM-EE, all other models fail to capture the observed spectral features for SM and WM years.

  17. Pre-monsoon aerosol characteristics over the Indo-Gangetic Basin: implications to climatic impact

    Science.gov (United States)

    Srivastava, A. K.; Tiwari, S.; Devara, P. C. S.; Bisht, D. S.; Srivastava, Manoj K.; Tripathi, S. N.; Goloub, P.; Holben, B. N.

    2011-05-01

    Sun/sky radiometer observations over the Indo-Gangetic Basin (IGB) region during pre-monsoon (from April-June 2009) have been processed to analyze various aerosol characteristics in the central and eastern IGB region, represented by Kanpur and Gandhi College, respectively, and their impacts on climate in terms of radiative forcing. Monthly mean aerosol optical depth (AOD at 500 nm) and corresponding Angstrom Exponent (AE at 440-870 nm, given within the brackets) was observed to be about 0.50 (0.49) and 0.51 (0.65) in April, 0.65 (0.74) and 0.67 (0.91) in May and 0.69 (0.45) and 0.77 (0.71) in June at Kanpur and Gandhi College, respectively. Results show a positive gradient in AOD and AE from central to eastern IGB region with the advancement of the pre-monsoon, which may be caused due to diverse geographical location of the stations having different meteorological conditions and emission sources. Relatively lower SSA was observed at the eastern IGB (0.89) than the central IGB (0.92) region during the period, which suggests relative dominance of absorbing aerosols at the eastern IGB as compared to central IGB region. The absorbing aerosol optical properties over the station suggest that the atmospheric absorption over central IGB region is mainly due to dominance of coarse-mode dust particles; however, absorption over eastern IGB region is mainly due to dominance of fine-particle pollution. The derived properties from sun/sky radiometer during pre-monsoon period are used in a radiative-transfer model to estimate aerosol radiative forcing at the top-of-the atmosphere (TOA) and at the surface over the IGB region. Relatively large TOA and surface cooling was observed at the eastern IGB as compared to the central IGB region. This translates into large heating of the atmosphere ranging from 0.45 to 0.55 K day-1 at Kanpur and from 0.45 to 0.59 K day-1 at Gandhi College.

  18. Sensitivity of a regional climate model to land surface parameterization schemes for East Asian summer monsoon simulation

    Science.gov (United States)

    Li, Wenkai; Guo, Weidong; Xue, Yongkang; Fu, Congbin; Qiu, Bo

    2016-10-01

    Land surface processes play an important role in the East Asian Summer Monsoon (EASM) system. Parameterization schemes of land surface processes may cause uncertainties in regional climate model (RCM) studies for the EASM. In this paper, we investigate the sensitivity of a RCM to land surface parameterization (LSP) schemes for long-term simulation of the EASM. The Weather Research and Forecasting (WRF) Model coupled with four different LSP schemes (Noah-MP, CLM4, Pleim-Xiu and SSiB), hereafter referred to as Sim-Noah, Sim-CLM, Sim-PX and Sim-SSiB respectively, have been applied for 22-summer EASM simulations. The 22-summer averaged spatial distributions and strengths of downscaled large-scale circulation, 2-m temperature and precipitation are comprehensively compared with ERA-Interim reanalysis and dense station observations in China. Results show that the downscaling ability of RCM for the EASM is sensitive to LSP schemes. Furthermore, this study confirms that RCM does add more information to the EASM compared to reanalysis that imposes the lateral boundary conditions (LBC) because it provides 2-m temperature and precipitation that are with higher resolution and more realistic compared to LBC. For 2-m temperature and monsoon precipitation, Sim-PX and Sim-SSiB simulations are more consistent with observation than simulations of Sim-Noah and Sim-CLM. To further explore the physical and dynamic mechanisms behind the RCM sensitivity to LSP schemes, differences in the surface energy budget between simulations of Ens-Noah-CLM (ensemble mean averaging Sim-Noah and Sim-CLM) and Ens-PX-SSiB (ensemble mean averaging Sim-PX and Sim-SSiB) are investigated and their subsequent impacts on the atmospheric circulation are analyzed. It is found that the intensity of simulated sensible heat flux over Asian continent in Ens-Noah-CLM is stronger than that in Ens-PX-SSiB, which induces a higher tropospheric temperature in Ens-Noah-CLM than in Ens-PX-SSiB over land. The adaptive

  19. Response of Groundwater table to Eucalyptus Plantations in a Tropical Monsoon Climate, Lake Tana Basin, Ethiopia

    Science.gov (United States)

    Enku, Temesgen; Melesse, Assefa; Ayana, Essaya; Tilahun, Seifu; Abate, Mengiste; Steenhuis, Tammo

    2017-04-01

    Given the increasing demand for water resources and the need for better management of regional water resources, it is essential to quantify the groundwater use by phreatophytes in tropical monsoon climates. Phreatophytes, like eucalyptus plantations are reported to be a groundwater sink and it could significantly affect the regional groundwater resources. In our study, the consumptive groundwater use of a closed eucalyptus plantation was calculated based on the diurnal water table fluctuations observed in monitoring wells for two dry monsoon phases in the Fogera plain, northwest of Ethiopia. Automated recorders were installed to monitor the hourly groundwater table fluctuations. The groundwater table fluctuates from maximum at early in the morning to minimum in the evening daily and generally declined linearly during the dry phase averaging 3.1 cm/day during the two year period under the eucalyptus plantations. The hourly eucalypts transpiration rate over the daylight hours follows the daily solar irradiance curve for clear sky days. It is minimal during the night and reaches maximum of 1.65mm/hour at mid-day. The evapotranspiration from the groundwater by eucalyptus plantations during the dry phases was estimated at about 2300mm from October 1 to 31 May, in 2015 compared to about 900mm without eucalyptus trees. The average daily evapotranspiration was 9.6mm. This is almost twice of the reference evapotranspiration in the area and 2.5 times the actual rate under fallow agricultural fields. Thus, water resources planning and management in the region needs to consider the effect of eucalyptus plantations on the availability of groundwater resources in the highlands of Ethiopia. Key words: Eucalyptus, Evapotranspiration, Groundwater, Ethiopia, Lake Tana

  20. Assessment of two versions of regional climate model in simulating the Indian Summer Monsoon over South Asia CORDEX domain

    Science.gov (United States)

    Pattnayak, K. C.; Panda, S. K.; Saraswat, Vaishali; Dash, S. K.

    2017-07-01

    This study assess the performance of two versions of Regional Climate Model (RegCM) in simulating the Indian summer monsoon over South Asia for the period 1998 to 2003 with an aim of conducting future climate change simulations. Two sets of experiments were carried out with two different versions of RegCM (viz. RegCM4.2 and RegCM4.3) with the lateral boundary forcings provided from European Center for Medium Range Weather Forecast Reanalysis (ERA-interim) at 50 km horizontal resolution. The major updates in RegCM4.3 in comparison to the older version RegCM4.2 are the inclusion of measured solar irradiance in place of hardcoded solar constant and additional layers in the stratosphere. The analysis shows that the Indian summer monsoon rainfall, moisture flux and surface net downward shortwave flux are better represented in RegCM4.3 than that in the RegCM4.2 simulations. Excessive moisture flux in the RegCM4.2 simulation over the northern Arabian Sea and Peninsular India resulted in an overestimation of rainfall over the Western Ghats, Peninsular region as a result of which the all India rainfall has been overestimated. RegCM4.3 has performed well over India as a whole as well as its four rainfall homogenous zones in reproducing the mean monsoon rainfall and inter-annual variation of rainfall. Further, the monsoon onset, low-level Somali Jet and the upper level tropical easterly jet are better represented in the RegCM4.3 than RegCM4.2. Thus, RegCM4.3 has performed better in simulating the mean summer monsoon circulation over the South Asia. Hence, RegCM4.3 may be used to study the future climate change over the South Asia.

  1. Holocene South Asian Monsoon Climate Change - Potential Mechanisms and Effects on Past Civilizations

    Science.gov (United States)

    Staubwasser, M.; Sirocko, F.; Grootes, P. M.; Erlenkeuser, H.; Segl, M.

    2002-12-01

    Planktonic oxygen isotope ratios from the laminated sediment core 63KA off the river Indus delta dated with 80 AMS radiocarbon ages reveal significant climate changes in the south Asian monsoon system throughout the Holocene. The most prominent event of the early-mid Holocene occurred after 8.4 ka BP and is within dating error of the GISP/GRIP event centered at 8.2 ka BP. The late Holocene is generally more variable, and shows non-periodic cycles in the multi-centennial frequency band. The largest change of the entire Holocene occurred at 4.2 ka BP and is concordant with the end of urban Harappan civilization in the Indus valley. Opposing isotopic trends across the northern Arabian Sea surface indicate a reduction in Indus river discharge at that time. Consequently, sustained drought may have initiated the archaeologically recorded interval of southeastward habitat tracking within the Harappan cultural domain. The hemispheric significance of the 4.2 ka BP event is evident from concordant climate change in the eastern Mediterranean and the Middle East. The late Holocene cycles in South Asia, which most likely represent drought cycles, vary between 250 and 800 years and are coherent with the evolution of cosmogenic radiocarbon production rates in the atmosphere. This suggests that solar variability is the fundamental cause behind late Holocene rainfall changes at least over south Asia.

  2. Effect of cloud microphysics on Indian summer monsoon precipitating clouds: A coupled climate modeling study

    Science.gov (United States)

    Hazra, Anupam; Chaudhari, Hemantkumar S.; Saha, Subodh K.; Pokhrel, Samir

    2017-04-01

    The quest for one of the most dominant processes controlling the large-scale circulations in the tropics is unraveled. The impact of cloud microphysical processes is known to have effects on rainfall and local atmospheric thermodynamics; however, its effect on the prevailing mean circulations is not yet studied. Two sets of coupled global climate model experiments (ICE and NO ICE microphysics) reveal that ice microphysics improves the strength of the Hadley circulation with respect to observation. Results pinpoint that ICE simulation enhances high cloud fraction (global tropics: 59%, India: 51%) and stratiform rain (global tropics: 5%, India: 15%) contribution. ICE and NO ICE cloud microphysics impacts differently on the outgoing longwave radiation (OLR), tropospheric temperature, and surface shortwave and longwave radiation. The effect of ice microphysics reduces OLR, which signifies deeper convection in the ICE run. The global annual average of the net radiation flux (shortwave and longwave) at the surface in ICE run (108.1 W/m2) is close to the observation (106 W/m2), which is overestimated in NO ICE run (112 W/m2). The result of apparent heat source term over the land and ocean surface eventually modifies regional Hadley circulation. Thus, the effect of ice microphysics in the global coupled model is important not only because of microphysics but also due to the radiation feedbacks. Therefore, better ice-phase microphysics is required in the new generation of climate forecast model, which may lead to improvements in the simulation of monsoon.

  3. Contrasting effects of winter and summer climate on alpine timberline evolution in monsoon-dominated East Asia

    Science.gov (United States)

    Cheng, Ying; Liu, Hongyan; Wang, Hongya; Piao, Shilong; Yin, Yi; Ciais, Philippe; Wu, Xiuchen; Luo, Yao; Zhang, Caina; Song, Yaqiong; Gao, Yishen; Qiu, Anan

    2017-08-01

    Alpine timberline is particularly sensitive to global climate change, with the danger of losing essential ecosystem services in high elevational regions. Its evolution is generally linked to annual average thermal regimes, and is regarded as an indicator of climate warming. However, the effect of uneven seasonal climate change stressed by the Hijioka et al. (2014) on alpine timberline dynamics in terms of both position migration and species composition remains unclear. Here, we documented approximately 6000 years of postglacial alpine timberline evolution on Mt. Tabai in the monsoon-dominated East Asian subtropical-temperate transition. We analyzed three high-resolution lacustrine sediment sequences located below, within, and above the current alpine timberline, an ecotone between the forest line and treeline, respectively. The timberline position appears to have varied coincidently with the temperature effect of cold East Asian Winter Monsoon (EAWM), implying that enhanced EAWM shortened the duration of the growing season and reduced forest survival at the alpine timberline. Unlike position migration, however, timberline species composition depends on summer precipitation. We found that drought-tolerant herb and shrub species were much more sensitive to variations in the water-bearing East Asian Summer Monsoon (EASM) than mesophytic trees at the alpine timberline. Our results suggest that prediction of future timberline dynamics should consider uneven seasonal climate changes.

  4. High Resolution Projections of Indian Summer Monsoon Synoptic Activity in a Warming Climate

    Science.gov (United States)

    Sukumaran, Sandeep; Ravindran, Ajayamohan; Thazhe Purayil, Sabin; Veluthedathekuzhiyil, Praveen

    2016-04-01

    The cyclonic systems of varying intensity, collectively known as Low Pressure Systems (LPS) are responsible more than 50% of the precipitation over Central India. Despite its importance, the future variability of LPS is poorly understood mainly due to the inadequate representation of these systems in global climate models. Insufficient spatial resolution of the current generation coupled models is a hindrance to resolve these storms properly. In order to overcome this problem, we use the Geophysical Fluid Dynamics Laboratory's (GFDL) High Resolution Atmospheric Model (HiRAM) to simulate current and future climate, with a model grid spacing of ~50km. The time slice experiments for current (1981 - 2005) and future (2071 - 2095) climate are forced with bias-corrected SSTs from Coupled Model Inter-comparison Project (CMIP5) historical and RCP8.5 simulations respectively. Four ensembles of the experiments are conducted with SST forcing taken from four different CMIP5 models. A benchmark simulation of the HiRAM model with observed SSTs shows that the model is capable of simulating the life cycle of the observed LPS reasonably well. In addition, HiRAM realistically simulates the observed LPS track density. Further, the track density in the historical ensemble is comparable with both observations and benchmark simulation. In the RCP8.5 simulations, an overall decline in the LPS activity is seen which is found to be related to the decrease in the high intensity systems in a warming environment. Consistent with the decrease in LPS activity, the seasonal mean monsoon precipitation is also declining in RCP8.5 simulations.

  5. A regional climate study of aerosol impacts on Indian monsoon and precipitations over the Himalayas

    Science.gov (United States)

    Solmon, F.; Von Hardenberg, J.; Nair, V.; Palazzi, E.

    2013-12-01

    In the context of the PAPRIKA program we are studying the potential effects of aerosol particle on Indian climate and Himalayan region. Using the RegCM4 regional climate model we performed some experiments including on-line representation of natural and anthropogenic aerosols for present day and future conditions over the CORDEX-India domain. Dynamical boundary forcing is taken for ERAI-Interim over the period 2000-2010, and chemical boundary-conditions are prescribed as a monthly climatology form an ECEARTH/CAM simulation for present day. Different set of anthropogenic emissions (SO2, carbonaceous aerosols) are considered (IPCC RCP4.5 and REAS) whereas natural aerosol (dust and sea-salt) are calculated on line. In order to account for aerosol radiative feedback on surface energy budget over the oceans, we also implemented a 'q-flux' slab ocean model as an alternative to pure SST forcing. After a step of validation of aerosol simulation against observations, we investigate through a series of experiments the dynamical feedback of direct radiative effect of aerosol over this domain, focusing specifically on Indian Monsoon and precipitation over the Himalayas. We discriminate the effect of anthropogenic vs. natural aerosol while outlining the main mechanism of the regional climate response, as well as the sensitivity to emissions inventory. Our results will be discussed notably against previous GCM based studies. Finally we will possibly discuss future projections based on RCP4.5 EC-EARTH forcing and including aerosol effects, as well as the potential radiative effects of absorbing aerosol deposition on the Himalayan snow covers.

  6. SUNYA Regional Climate Model Simulations of East Asia Summer Monsoon: Effects of Cloud Vertical Structure on the Surface Energy Balance

    Directory of Open Access Journals (Sweden)

    Wei Gong Wei-Chyung Wang

    2007-01-01

    Full Text Available We used the State University of New York at Albany (SUNYA regional climate model to study the effect of cloud vertical distribution in affecting the surface energy balance of the East Asia summer monsoon (EASM. Simulations were conducted for the summers of 1988 and 1989, during which large contrast in the intra-seasonal cloud radiative forcing (CRF was observed at the top of the atmosphere.

  7. The Preboreal-like Asian monsoon climate in the early last interglacial period recorded from the Dark Cave, Southwest China

    Science.gov (United States)

    Jiang, Xiuyang; He, Yaoqi; Wang, Xiaoyan; Sun, Xiaoshuang; Hong, Hui; Liu, Juan; Yu, Tsai-Luen; Li, Zhizhong; Shen, Chuan-Chou

    2017-08-01

    Transitions of glacial-interglacial cycles are critical periods for Quaternary climate shifts. Here, we present new, decadal resolution Asian summer monsoon (ASM) record from three stalagmites obtained from the Dark Cave in southwestern China over 130-114 thousand years ago (ka, before CE 1950). Chronology was anchored by 28 230Th dates with typical uncertainties of ±0.3-1.0 kyr, allowing an assessment of timing and transition of climate changes during the onset and end of the last interglacial. An agreement between this new and previous stalagmite δ18O records supports that summer insolation predominates orbital-scale ASM evolution. A 2-3 kyr-long gradually increasing ASM period, analogous to the classical Preboreal episode in the early Holocene, follows the termination of a weak monsoon interval at 129.0 ± 0.8 ka. This finding suggests a strong influence of high-latitude ice-sheet dynamics on Asian monsoonal conditions during the early interglacial period. An abrupt end of the marine isotope stage 5e at 118.8 ± 0.6 ka was probably caused by the internal climate system threshold effects.

  8. Impact of GCM boundary forcing on regional climate modeling of West African summer monsoon precipitation and circulation features

    Science.gov (United States)

    Kebe, Ibourahima; Sylla, Mouhamadou Bamba; Omotosho, Jerome Adebayo; Nikiema, Pinghouinde Michel; Gibba, Peter; Giorgi, Filippo

    2017-03-01

    In this study, the latest version of the International Centre for Theoretical Physics Regional Climate Model (RegCM4) driven by three CMIP5 Global Climate Models (GCMs) is used at 25 km grid spacing over West Africa to investigate the impact of lateral boundary forcings on the simulation of monsoon precipitation and its relationship with regional circulation features. We find that the RegCM4 experiments along with their multimodel ensemble generally reproduce the location of the main precipitation characteristics over the region and improve upon the corresponding driving GCMs. However, the provision of different forcing boundary conditions leads to substantially different precipitation magnitudes and spatial patterns. For instance, while RegCM4 nested within GFDL-ESM-2M and HadGEM2-ES exhibits some underestimations of precipitation and an excessively narrow Intertropical Convergence Zone, the MPI-ESM-MR driven run produces precipitation spatial distribution and magnitudes more similar to observations. Such a superior performance originates from a much better simulation of the interactions between baroclinicity, temperature gradient and African Easterly Jet along with an improved connection between the Isentropic Potential Vorticity, its gradient and the African Easterly Waves dynamics. We conclude that a good performing GCM in terms of monsoon dynamical features (in this case MPI-ESM-MR) is needed to drive RCMs in order to achieve a better representation of the West Africa summer monsoon precipitation.

  9. The Asian monsoon's role in atmospheric heat transport responses to orbital and millennial-scale climate change

    Science.gov (United States)

    McGee, D.; Green, B.; Donohoe, A.; Marshall, J.

    2015-12-01

    Recent studies have provided a framework for understanding the zonal-mean position of the tropical rain belt by documenting relationships between rain belt latitude and atmospheric heat transport across the equator (Donohoe et al., 2013). Modern seasonal and interannual variability in globally-averaged rain belt position (often referred to as 'ITCZ position') reflects the interhemispheric heat balance, with the rain belt's displacement toward the warmer hemisphere directly proportional to atmospheric heat transport into the cooler hemisphere. Model simulations suggest that rain belt shifts are likely to have obeyed the same relationship with interhemispheric heat transport in response to past changes in orbital parameters, ice sheets, and ocean circulation. This relationship implies that even small (±1 degree) shifts in the mean rain belt require large changes in hemispheric heat budgets, placing tight bounds on mean rain belt shifts in past climates. This work has primarily viewed tropical circulation in two dimensions, as a pair of zonal-mean Hadley cells on either side of the rain belt that are displaced north and south by perturbations in hemispheric energy budgets, causing the atmosphere to transport heat into the cooler hemisphere. Here we attempt to move beyond this zonal-mean perspective, motivated by arguments that the Asian monsoon system, rather than the zonal-mean circulation, plays the dominant role in annual-mean heat transport into the southern hemisphere in the modern climate (Heaviside and Czaja, 2012; Marshall et al., 2014). We explore a range of climate change experiments, including simulations of North Atlantic cooling and mid-Holocene climate, to test whether changes in interhemispheric atmospheric heat transport are primarily driven by the mean Hadley circulation, the Asian monsoon system, or other regional-scale atmospheric circulation changes. The scalings that this work identifies between Asian monsoon changes and atmospheric heat

  10. Predictability during active break phases of Indian summer monsoon in an ensemble prediction system using climate forecast system

    Science.gov (United States)

    Abhilash, S.; Sahai, A. K.; Pattnaik, S.; De, S.

    2013-08-01

    This study examines the phase dependant temporal and spatial error evolution and prediction of active break spells of Indian summer monsoon rainfall in an ensemble prediction system (EPS) on a pentad time scale using climate forecast system (CFS). The EPS system shows systematic wet bias (overestimation) over west coast over the Arabian Sea and Myanmar coast and dry bias (underestimation) over Indian land mass even at pentad 1 lead and these biases consistently increase up to 4 pentad lead and saturate thereafter. Irrespective of the phases of the monsoon, the lower bound of predictability is 2 pentads, while upper bound of predictability for initial conditions starting from active phase saturates at 3 pentads and for break and transition phases predictability error saturates at a later stage at about 5 pentad. Initial conditions started from transition phase shows higher potential predictability followed by break phase and then active phase.

  11. Simulation of Asian Monsoon Seasonal Variations with Climate Model R42L9/LASG

    Institute of Scientific and Technical Information of China (English)

    王在志; 吴国雄; 吴统文; 宇如聪

    2004-01-01

    The seasonal variations of the Asian monsoon were explored by applying the atmospheric general circulation model R42L9 that was developed recently at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences (LASG/IAP/CAS). The 20-yr (1979-1998) simulation was done using the prescribed20-yr monthly SST and sea-ice data as required by Atmospheric Model Intercomparison Project (AMIP)Ⅱ in the model. The monthly precipitation and monsoon circulations were analyzed and compared with the observations to validate the model's performance in simulating the climatological mean and seasonal variations of the Asian monsoon. The results show that the model can capture the main features of the spatial distribution and the temporal evolution of precipitation in the Indian and East Asian monsoon areas. The model also reproduced the basic patterns of monsoon circulation. However, some biases exist in this model. The simulation of the heating over the Tibetan Plateau in summer was too strong. The overestimated heating caused a stronger East Asian monsoon and a weaker Indian monsoon than the observations. In the circulation fields, the South Asia high was stronger and located over the Tibetan Plateau. The western Pacific subtropical high was extended westward, which is in accordance with the observational results when the heating over the Tibetan Plateau is stronger. Consequently, the simulated rainfall around this area and in northwest China was heavier than in observations, but in the Indian monsoon area and west Pacific the rainfall was somewhat deficient.

  12. A Possible Impact of Cooling over the Tibetan Plateau on the Mid-Holocene East Asian Monsoon Climate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    By using a 9-level global atmospheric general circulation model developed at the Institute of Atmospheric Physics (IAP9L-AGCM) under the Chinese Academy of Sciences, the authors investigated the response of the East Asian monsoon climate to changes both in orbital forcing and the snow and glaciers over the Tibetan Plateau at the mid-Holocene, about 6000 calendar years before the present (6kyr BP). With the Earth's orbital parameters appropriate for the mid-Holocene, the IAP9L-AGCM computed warmer and wetter conditions in boreal summer than for the present day. Under the precondition of continental snow and glacier cover existing over part of the Tibetan Plateau at the mid-Holocene, the authors examined the regional climate response to the Tibetan Plateau cooling. The simulations indicated that climate changes in South Asia and parts of central Asia as well as in East Asia are sensitive to the Tibetan Plateau cooling at the mid-Holocene, showing a significant decrease in precipitation in northern India, northern China and southern Mongolia and an increase in Southeast Asia during boreal summer.The latter seems to correspond to the weakening, southeastward shift of the Asian summer monsoon system resulting from reduced heat contrast between the Eurasian continent and the Pacific and Indian Oceans when a cooling over the Tibetan Plateau was imposed. The simulation results suggest that the snow and glacier environment over the Tibetan Plateau is an important factor for mid-Holocene climate change in the areas highly influenced by the Asian monsoon.

  13. Asian Eocene monsoons as revealed by leaf architectural signatures

    Science.gov (United States)

    Spicer, Robert A.; Yang, Jian; Herman, Alexei B.; Kodrul, Tatiana; Maslova, Natalia; Spicer, Teresa E. V.; Aleksandrova, Galina; Jin, Jianhua

    2016-09-01

    The onset and development of the Asian monsoon systems is a topic that has attracted considerable research effort but proxy data limitations, coupled with a diversity of definitions and metrics characterizing monsoon phenomena, have generated much debate. Failure of geological proxies to yield metrics capable of distinguishing between rainfall seasonality induced by migrations of the Inter-tropical Convergence Zone (ITCZ) from that attributable to topographically modified seasonal pressure reversals has frustrated attempts to understand mechanisms underpinning monsoon development and dynamics. Here we circumvent the use of such single climate parameter metrics in favor of detecting directly the distinctive attributes of different monsoon regimes encoded in leaf fossils. Leaf form adapts to the prevailing climate, particularly under the extreme seasonal stresses imposed by monsoons, so it is likely that fossil leaves carry a unique signature of past monsoon regimes. Leaf form trait spectra obtained from fossils from Eocene basins in southern China were compared with those seen in modern leaves growing under known climate regimes. The fossil leaf trait spectra, including those derived from previously published fossil floras from northwestern India, were most similar to those found in vegetation exposed to the modern Indonesia-Australia Monsoon (I-AM), which is largely a product of seasonal migrations of the ITCZ. The presence of this distinctive leaf physiognomic signature suggests that although a monsoon climate existed in Eocene time across southern Asia the characteristics of the modern topographically-enhanced South Asia Monsoon had yet to develop. By the Eocene leaves in South Asia had become well adapted to an I-AM type regime across many taxa and points to the existence of a pervasive monsoon climate prior to the Eocene. No fossil trait spectra typical of exposure to the modern East Asia monsoon were seen, suggesting the effects of this system in southern

  14. East Asian monsoon variation and climate changes in Jeju Island, Korea, during the latest Pleistocene to early Holocene

    Science.gov (United States)

    Lee, Seung Hyoun; Lee, Yong Il; Yoon, Ho Il; Yoo, Kyu-Cheul

    2008-09-01

    A 4.96-m-long sediment core from the Hanon paleo-maar in Jeju Island, Korea was studied to investigate the paleoclimatic change and East Asian monsoon variations during the latest Pleistocene to early Holocene (23,000-9000 cal yr BP). High-resolution TOC content, magnetic susceptibility, and major element composition data indicate that Jeju Island experienced the coldest climate around 18,000 cal yr BP, which corresponds to the last glacial maximum (LGM). Further, these multi-proxy data show an abrupt shift in climatic regime from cold and arid to warm and humid conditions at around 14,000 cal yr BP, which represents the commencement of the last major deglaciation. After the last major deglaciation, the TOC content decreased from 13,300 to 12,000 cal yr BP and from 11,500 to 9800 cal yr BP, thereby reflecting the weakening of the summer monsoon. The LGM in Jeju Island occurred later in comparison with the Chinese Loess Plateau. Such a disparity in climatic change events between central China and Jeju Island appears to be caused by the asynchrony between the coldest temperature event and the minimum precipitation event in central China and by the buffering effect of the Pacific Ocean.

  15. Multi-year simulation of the East Asian Monsoon and Precipitation in China using a Regional Climate Model and Evaluation

    Institute of Scientific and Technical Information of China (English)

    LI Qiaoping; DING Yihui

    2005-01-01

    By using the regional climate model (RegCM_NCC), East Asian monsoon and precipitation over China during 1998 to 2002 are simulated. Results show that the model can well reproduce the seasonal patterns of mean circulation as well as the intensity and seasonal march of the East Asian monsoon. The simulated onset or retreat time of the West Pacific subtropical high, and the intensity and location of the South Asian high are consistent with the fact. The spatial distribution and transport of moisture in lower layer are also well simulated. The seasonal variations of regional rainfall and temperature are reproduced in the model, with three northward shift time and intensity of the rain belts over the sub-regions (such as Mid-Lower Yangtze basins and South China) well corresponding to the observation. However, the simulated summer monsoon is stronger compared with NCEP reanalysis fields, with the location of subtropical high being further north by 2-3 degrees than normal. Error evaluation shows that there is a discernible systematic bias in the simulated mean circulation pattern, with air temperature bias being positive over the land and negative over the ocean in the lower troposphere in summer. The systematic bias exaggerates the summer temperature difference between the land and ocean, which may be a main responsible factor for the stronger simulated summer monsoon, thus resulting in the overestimated rainfall in North China and it can not reflect well the abnormal rainfall distribution in these 5 years. The deficiency may be mainly contributed to the complex topography and cloud-radiation parameterization scheme. The analyses also indicate that it is difficult to simulate the persistent abnormal precipitation pattern over China. It is necessary to improve the model's capability further.

  16. Climate@Home: Crowdsourcing Climate Change Research

    Science.gov (United States)

    Xu, C.; Yang, C.; Li, J.; Sun, M.; Bambacus, M.

    2011-12-01

    Climate change deeply impacts human wellbeing. Significant amounts of resources have been invested in building super-computers that are capable of running advanced climate models, which help scientists understand climate change mechanisms, and predict its trend. Although climate change influences all human beings, the general public is largely excluded from the research. On the other hand, scientists are eagerly seeking communication mediums for effectively enlightening the public on climate change and its consequences. The Climate@Home project is devoted to connect the two ends with an innovative solution: crowdsourcing climate computing to the general public by harvesting volunteered computing resources from the participants. A distributed web-based computing platform will be built to support climate computing, and the general public can 'plug-in' their personal computers to participate in the research. People contribute the spare computing power of their computers to run a computer model, which is used by scientists to predict climate change. Traditionally, only super-computers could handle such a large computing processing load. By orchestrating massive amounts of personal computers to perform atomized data processing tasks, investments on new super-computers, energy consumed by super-computers, and carbon release from super-computers are reduced. Meanwhile, the platform forms a social network of climate researchers and the general public, which may be leveraged to raise climate awareness among the participants. A portal is to be built as the gateway to the climate@home project. Three types of roles and the corresponding functionalities are designed and supported. The end users include the citizen participants, climate scientists, and project managers. Citizen participants connect their computing resources to the platform by downloading and installing a computing engine on their personal computers. Computer climate models are defined at the server side. Climate

  17. Siliceous microplankton fluxes and seasonal variations in the central South China Sea during 1993-1995:monsoon climate and El Ni(n)o responses

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Seasonal variations of radiolarian and diatom fluxes in the central South China Sea during 1993-1995 were overwhelmingly controlled by monsoon climate. Radiolarian and diatom increased obviously during the Northeast (from November to February) and Southwest (from June to September) monsoons and decreased during the periods between the monsoons. The change of circulation driven by the monsoons improved water exchange in the different areas that brought rich nutrient materials for the surface microplankton, thereby enhancing radiolarian and diatom fluxes. Variation of radiolarian flux coincided with organic carbon flux, surface primary and export productivities. High radiolarian flux corresponded to high surface primary productivity. Radiolarian and diatom fluxes raised abnormally during 1994-1995 could be attributed to the El Ni(n)o event during the period.

  18. Measuring the monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaswamy, V.; Nair, R.R.

    of the monsoons, there are also fluctuations arising from human activities. Most scientists believe that large-scale deforestation and burning of fossil fuels will alter global climatic patterns significantly. For the sake of those people whose lives...

  19. Simulation of the future change of East Asian monsoon climate using the IPCC SRES A2 and B2 scenarios

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper, we applied the newest emission scenarios of the sulfur and greenhouse gases, i.e. Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES) A2 and B2 scenarios, to investigating the change of the East Asian climate in the last three decades of the 21st century with an atmosphere-ocean coupled general circulation model. The global warming enlarges the land-sea thermal contrast and, hence, enhances (reduces) the East Asian summer (winter) monsoon circulation. The precipitation from the Yangtze and Huaihe river valley to North China increases significantly. In particular, the strong rainfall increase over North China implies that the East Asian rainy area would expand northward. In addition, from the southeastern coastal area to North China, the rainfall would increase significantly in September, implying that the rainy period of the East Asian monsoon would be prolonged about one month. In July, August and September, the interannual variability of the precipitation enhances evidently over North China, meaning a risk of flooding in the future.

  20. A Possible Role of Solar Radiation and Ocean in the Mid-Holocene East Asian Monsoon Climate

    Institute of Scientific and Technical Information of China (English)

    魏江峰; 王会军

    2004-01-01

    An atmospheric general circulation model (AGCM) and an oceanic general circulation model (OGCM) are asynchronously coupled to simulate the climate of the mid-Holocene period.The role of the solarradiation and ocean in the mid-Holocene East Asian monsoon climate is analyzed and some mechanisms are revealed.At the forcing of changed solar radiation induced by the changed orbital parameters and the changed SST simulated by the OGCM,compared with when there is orbital forcing alone,there is more precipitation and the monsoon is stronger in the summer of East Asia,and the winter temperature increases over China.These agree better with the reconstructed data.It is revealed that the change of solar radiation can displace northward the ITCZ and the East Asia subtropical jet,which bring more precipitation over the south of Tibet and North and Northeast China.By analyzing the summer meridional latent heat transport,it is found that the influence of solar radiation change is mainly to increase the convergence of atmosphere toward the land,and the influence of SST change is mainly to transport more moisture to the sea surface atmosphere.Their synergistic effect on East Asian precipitation is much stronger than the sum of their respective effects.

  1. Norwegian climate research. An evaluation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    From the executive summary; Based on our evaluation, we make six major recommendations and provide suggestions for how these might be implemented. 1. Establish a clear and coherent national strategy for climate research and its funding. 2. The Research Council of Norway should develop a new integrated long-term climate research programme. 3. Build on strengths and develop capacities in areas where Norway currently lacks sufficient scientific expertise. 4. Ensure societal relevance as well as inter- and transdisciplinarity in research. 5. Emphasise collaboration and cooperation as a basis for successful climate research. 6. Prioritise outreach and stakeholder interaction.(Author)

  2. Norwegian climate research. An evaluation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-06-15

    [English] In early 2011, the Norwegian Research Council (RCN) appointed a committee to review Norwegian climate research. The aim of the evaluation was to provide a critical review of Norwegian climate research in an international perspective and to recommend measures to enhance the quality, efficiency and relevance of future climate research. The Evaluation Committee met three times: in August and December 2011, and March 2012. RCN sent an invitation to 140 research organisations to participate by delivering background information on their climate research. Based on the initial response, 48 research units were invited to submit self-assessments and 37 research units responded. These were invited to hearings during the second meeting of the Evaluation Committee in December. In our judgement, a great majority of the most active research units are covered by this evaluation report. It should be emphasised that the evaluation concerned the Norwegian landscape of climate research rather than individual scientists or research units. Bibliometric analyses and social network analyses provided additional information. We are aware of problems in making comparisons across disciplinary publishing traditions, especially with regard to the differences between the natural and social sciences and the humanities. The Evaluation Committee also reviewed a number of governmental and RCN policy documents and conducted interviews with the chairs of the NORKLIMA Programme Steering Board and the Norwegian IPY Committee, as well as with staff members of RCN. Additional information was received from hearings organised by RCN with the science communities and various stakeholders in January 2012. For the purpose of this evaluation, climate research was divided into three broad thematic areas: 1. The climate system and climate change: research on climate variability and change in order to improve our capability of understanding climate and of projecting climate change for different time

  3. Holocene climatic change in Hunshandake Desert

    Institute of Scientific and Technical Information of China (English)

    JIN Heling; SU Zhizhu; SUN Liangying; SUN Zhong; ZHANG Hong; JIN Liya

    2004-01-01

    Research on the geological data of Hunshandake Desert in China monsoon region revealed that Holocene summer monsoon had experienced six prevailing periods and seven weakening periods. The climatic humidity and the vegetation had also undergone the similar periodical variation influenced by the monsoon periodicity. The period when summer monsoon prevailed or winter monsoon weakened and climatic humidity and vegetation coverage relatively increased, corresponded to the global warming events;whereas the period when summer monsoon weakened or winter monsoon prevailed and climatic humidity and vegetation coverage relatively decreased, corresponded to the arid events in middle to low latitudes and the cold events in North Atlantic. As for the changing regularity of summer monsoon intensity there were two distinct periodicities of 1456 years and 494 years, also these two periodicities had global significance.

  4. West African monsoon intraseasonal activity and its daily precipitation indices in regional climate models: diagnostics and challenges

    Science.gov (United States)

    Poan, E. D.; Gachon, P.; Dueymes, G.; Diaconescu, E.; Laprise, R.; Seidou Sanda, I.

    2016-11-01

    The West African monsoon intraseasonal variability has huge socio-economic impacts on local populations but understanding and predicting it still remains a challenge for the weather prediction and climate scientific community. This paper analyses an ensemble of simulations from six regional climate models (RCMs) taking part in the coordinated regional downscaling experiment, the ECMWF ERA-Interim reanalysis (ERAI) and three satellite-based and observationally-constrained daily precipitation datasets, to assess the performance of the RCMs with regard to the intraseasonal variability. A joint analysis of seasonal-mean precipitation and the total column water vapor (also called precipitable water— PW) suggests the existence of important links at different timescales between these two variables over the Sahel and highlights the relevance of using PW to follow the monsoon seasonal cycle. RCMs that fail to represent the seasonal-mean position and amplitude of the meridional gradient of PW show the largest discrepancies with respect to seasonal-mean observed precipitation. For both ERAI and RCMs, spectral decompositions of daily PW as well as rainfall show an overestimation of low-frequency activity (at timescales longer than 10 days) at the expense of the synoptic (timescales shorter than 10 days) activity. Consequently, the effects of the African Easterly Waves and the associated mesoscale convective systems are substantially underestimated, especially over continental regions. Finally, the study investigates the skill of the models with respect to hydro-climatic indices related to the occurrence, intensity and frequency of precipitation events at the intraseasonal scale. Although most of these indices are generally better reproduced with RCMs than reanalysis products, this study indicates that RCMs still need to be improved (especially with respect to their subgrid-scale parameterization schemes) to be able to reproduce the intraseasonal variance spectrum adequately.

  5. Exploring recent and projected climate change in a steep monsoonal catchment in the middle Himalaya through innovative synthesis of local observations, gridded datasets and community engagement

    Science.gov (United States)

    Forsythe, Nathan; Pritchard, Davis; Tiwari, Prakash; Fowler, Hayley; Kumaun, Bhagwati

    2016-04-01

    Under the auspices of an "Innovation Partnerships" programme research exchange grant jointly funded by the India Department of Science and Technology and the British Council, Kumaun University and Newcastle University have been collaboratively exploring the recorded historical and projected future climate change implications for a case study catchment, the Ramgad river, in the Kumaon Lesser Himalaya (Uttarakhand state, India). This work weaves together diverse research strands with the aim of producing a coherent thorough characterisation of the impacts of recent/on-going and likely climate evolution on local communities. Participatory research activities in multiple villages in the case study catchment have yielded a consistent narrative of changes posed by the increasingly erratic monsoonal rainfall as well as upward displacement and replacement crops in their historical elevation ranges due to temperature change. Multi-decadal climate records from both local observations and global meteorological records reveal a more complex picture with strong seasonal asymmetry of changes in both temperature and precipitation: a) trend analysis shows mild weakening of the early phase (May, July) but strengthen in the later stages (August, September); b) temperature trends show much stronger warming in late winter and early spring (February to April) than the rest of the year with additional asymmetry in both sign and magnitude of change between individual components (Tmax, Tmin) of the diurnal temperature cycle. On-going research seeks to associate this asymmetry with causal mechanisms (cloud radiative effect, atmospheric circulation). Analysis of historical records will provide the basis for validation and assessment of individual regional climate model projections from the CORDEX South Asia domain ensemble. For the terraced agricultural communities of the Kumaon Himalaya, the most directly consequential effects of climate variability and change are impacts on crop yields

  6. Volcanic Eruptions and Climate: Outstanding Research Issues

    Science.gov (United States)

    Robock, Alan

    2016-04-01

    Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about one year. The radiative and chemical effects of this aerosol cloud produce responses in the climate system. Based on observations after major eruptions of the past and experiments with numerical models of the climate system, we understand much about their climatic impact, but there are also a number of unanswered questions. Volcanic eruptions produce global cooling, and are an important natural cause of interannual, interdecadal, and even centennial-scale climate change. One of the most interesting volcanic effects is the "winter warming" of Northern Hemisphere continents following major tropical eruptions. During the winter in the Northern Hemisphere following every large tropical eruption of the past century, surface air temperatures over North America, Europe, and East Asia were warmer than normal, while they were colder over Greenland and the Middle East. This pattern and the coincident atmospheric circulation correspond to the positive phase of the Arctic Oscillation. While this response is observed after recent major eruptions, most state-of-the-art climate models have trouble simulating winter warming. Why? High latitude eruptions in the Northern Hemisphere, while also producing global cooling, do not have the same impact on atmospheric dynamics. Both tropical and high latitude eruptions can weaken the Indian and African summer monsoon, and the effects can be seen in past records of flow in the Nile and Niger Rivers. Since the Mt. Pinatubo eruption in the Philippines in 1991, there have been no large eruptions that affected climate, but the cumulative effects of small eruptions over the past decade have had a small effect on global temperature trends. Some important outstanding research questions include: How much seasonal, annual, and decadal predictability is possible following a large volcanic eruption? Do

  7. Holocene climate changes in the mid-high-latitude-monsoon margin reflected by the pollen record from Hulun Lake, northeastern Inner Mongolia

    Science.gov (United States)

    Wen, Ruilin; Xiao, Jule; Chang, Zhigang; Zhai, Dayou; Xu, Qinghai; Li, Yuecong; Itoh, Shigeru; Lomtatidze, Zaur

    2010-03-01

    Pollen-assemblage data from a sediment core from Hulun Lake in northeastern Inner Mongolia describe the changes in the vegetation and climate of the East Asian monsoon margin during the Holocene. Dry steppe dominated the lake basin from ca. 11,000 to 8000 cal yr BP, suggesting a warm and dry climate. Grasses and birch forests expanded 8000 to 6400 cal yr BP, implying a remarkable increase in the monsoon precipitation. From 6400 to 4400 cal yr BP, the climate became cooler and drier. Chenopodiaceae dominated the interval from 4400 to 3350 cal yr BP, marking extremely dry condition. Artemisia recovered 3350-2050 cal yr BP, denoting an amelioration of climatic conditions. Both temperature and precipitation decreased 2050 to 1000 cal yr BP as indicated by decreased Artemisia and the development of pine forests. During the last 1000 yr, human activities might have had a significant influence on the environment of the lake region. We suggest that the East Asian summer monsoon did not become intensified until 8000 cal yr BP due to the existence of remnant ice sheets in the Northern Hemisphere. Changes in the monsoon precipitation on millennial to centennial scales would be related to ocean-atmosphere interactions in the tropical Pacific.

  8. A model perspective on orbital forcing of monsoons and Mediterranean climate using EC-Earth (Utrecht Studies in Earth Sciences 055)

    NARCIS (Netherlands)

    Bosmans, J.H.C.

    2014-01-01

    This thesis focuses on orbitally forced changes of monsoons and Mediterranean climate. Changes in the shape of the Earths orbit around the Sun and its rotational axis govern the seasonal and latitudinal distribution of incoming solar radiation on time scales of thousands to millions of years. The th

  9. The mechanism and scenarios of how mean annual runoff varies with climate change in Asian monsoon areas

    Science.gov (United States)

    Chen, Junxu; Xia, Jun; Zhao, Changsen; Zhang, Shifeng; Fu, Guobin; Ning, Like

    2014-09-01

    Understanding the effects of climate change on runoff is important for the sustainable management of water resources. However, the mechanism of such effects in the Asian monsoon region remains unclear. This study revisits Fu's two-parameter climate elasticity index and enhances it by using the Gardner function to strengthen the former's prediction reliability when the future climate condition is beyond the historical range. Then the improved method was applied to study the elasticity change with temperature and precipitation in the eastern monsoon basins of China, whereas to explore the mechanism of climate change on runoff. Furthermore, the runoff change and the elasticity of the study area from 2020 to 2050 under representative concentration pathways (RCPs) were predicted. Results show that the trend of elasticity change assumes a centrosymmetric picture with the symmetric point (0, 0). Different catchments respond differently to the same climate change scenario: the sensitivity of the Haihe Basin is the highest; those of Yellow, Huaihe, Liaohe, Songhua, Pearl, Yangtze, and Southeast Rivers are lower, in descending order. The changing mode of precipitation and temperature differs greatly to keep the runoff unchanged. For semi-humid regions in which the mean annual temperature ranges from 0.71 °C to 9.0 °C, such as the basins of Songhua, Liaohe, Haihe, and Yellow, a 1 °C increase in temperature requires a corresponding 3.2-4.0% increase in precipitation to keep the runoff unchanged. However, in wet regions, such as the basins of Yangtze, Southeast Rivers, and Pearl, the same change in temperature requires a less than 2.8% increase in precipitation to keep the runoff unchanged. In the future, the runoff in most basins may decrease in different degrees. The decreasing velocity of the runoff is the fastest in the RCP8.5 scenario and the decreasing trend of the runoff slows down under the RCP4.5 and RCP2.6 scenarios. The proposed method can be applied to other

  10. A road map for improving dry-bias in simulating the South Asian monsoon precipitation by climate models

    Science.gov (United States)

    Goswami, Bidyut Bikash; Goswami, B. N.

    2017-09-01

    An outstanding problem of climate models is the persistent dry bias in simulating precipitation over the south Asian summer monsoon region. Guided by observations, it is hypothesized that the dry-bias in simulating precipitation by the models is related to underestimation of high pass variance by most models. An analysis of the simulated mean and variance in precipitation by 36 coupled models show that the dry bias in simulating the mean precipitation by the models is indeed proportional to the underestimation of the variance. Models also indicate that the underestimation of the high-pass variance arise due to the underestimation of the intense rainfall events by models. Further, it is found that the higher resolution models simulate increasingly reduced dry bias by simulating high-frequency variance better through better simulation probability of intense rainfall events. The robustness of our findings over different regions and during both boreal summer and winter seasons indicates the universality of the hypothesis.

  11. The representation of low-level clouds during the West African monsoon in weather and climate models

    Science.gov (United States)

    Kniffka, Anke; Hannak, Lisa; Knippertz, Peter; Fink, Andreas

    2016-04-01

    The West African monsoon is one of the most important large-scale circulation features in the tropics and the associated seasonal rainfalls are crucial to rain-fed agriculture and water resources for hundreds of millions of people. However, numerical weather and climate models still struggle to realistically represent salient features of the monsoon across a wide range of scales. Recently it has been shown that substantial errors in radiation and clouds exist in the southern parts of West Africa (8°W-8°E, 5-10°N) during summer. This area is characterised by strong low-level jets associated with the formation of extensive ultra-low stratus clouds. Often persisting long after sunrise, these clouds have a substantial impact on the radiation budget at the surface and thus the diurnal evolution of the planetary boundary layer (PBL). Here we present some first results from a detailed analysis of the representation of these clouds and the associated PBL features across a range of weather and climate models. Recent climate model simulations for the period 1991-2010 run in the framework of the Year of Tropical Convection (YOTC) offer a great opportunity for this analysis. The models are those used for the latest Assessment Report of the Intergovernmental Panel on Climate Change, but for YOTC the model output has a much better temporal resolution, allowing to resolve the diurnal cycle, and includes diabatic terms, allowing to much better assess physical reasons for errors in low-level temperature, moisture and thus cloudiness. These more statistical climate model analyses are complemented by experiments using ICON (Icosahedral non-hydrostatic general circulation model), the new numerical weather prediction model of the German Weather Service and the Max Planck Institute for Meteorology. ICON allows testing sensitivities to model resolution and numerical schemes. These model simulations are validated against (re-)analysis data, satellite observations (e.g. CM SAF cloud and

  12. Quantifying climatic variability in monsoonal northern China over the last 2200 years and its role in driving Chinese dynastic changes

    Science.gov (United States)

    Li, Jianyong; Dodson, John; Yan, Hong; Zhang, David D.; Zhang, Xiaojian; Xu, Qinghai; Lee, Harry F.; Pei, Qing; Cheng, Bo; Li, Chunhai; Ni, Jian; Sun, Aizhi; Lu, Fengyan; Zong, Yongqiang

    2017-03-01

    Our understanding on the spatial-temporal patterns of climatic variability over the last few millennia in the East Asian monsoon-dominated northern China (NC), and its role at a macro-scale in affecting the prosperity and depression of Chinese dynasties is limited. Quantitative high-resolution, regionally-synthesized palaeoclimatic reconstructions as well as simulations, and numerical analyses of their relationships with various fine-scale, numerical agro-ecological, social-economic, and geo-political historical records during the period of China's history, are presented here for NC. We utilize pollen data together with climate modeling to reconstruct and simulate decadal- to centennial-scale variations in precipitation or temperature for NC during the last 2200 years (-200-2000 AD). We find an overall cyclic-pattern (wet/warm or dry/cold) in the precipitation and temperature anomalies on centennial- to millennial-scale that can be likely considered as a representative for the entire NC by comparison with other related climatic records. We suggest that solar activity may play a key role in driving the climatic fluctuations in NC during the last 22 centuries, with its quasi ∼100, 50, 23, or 22-year periodicity clearly identified in our climatic reconstructions. We employ variation partitioning and redundancy analysis to quantify the independent effects of climatic factors on accounting for the total variation of 17 fine-grained numerical Chinese historical records. We quantitatively illustrate that precipitation (67.4%) may have been more important than temperature (32.5%) in causing the overall agro-ecological and macro-geopolitical shifts in imperial China with NC as the central ruling region and an agricultural heartland over the last 2200 years.

  13. Late Holocene (~ 2 ka) East Asian Monsoon variations inferred from river discharge and climate interrelationships in the Pearl River Estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Nan, Q.; Li, T.; Chen, J.; Nigam, R.

    -size distributions, TOC contents, and δ13Corg variations appear to be directly related to monsoon precipitation in the sediment source area. An increased East Asian summer monsoon rainfall (EASM) and/or an enhanced East Asian winter monsoon rainfall could...

  14. Assessment of Seasonal Energy Efficiency Strategies of a Double Skin Façade in a Monsoon Climate Region

    Directory of Open Access Journals (Sweden)

    Choongwan Koo

    2013-08-01

    Full Text Available As climate change and global warming have become two of the most significant environmental issues today, the double-skin façade (DSF is getting considerable attention as an energy-efficient passive design. This study is aimed at assessing the seasonal energy efficiency strategies of a DSF targeting library facilities in the climate region with hot summers and cold winters. Toward this end, this study was conducted in four steps: (i establishment of seasonal energy-efficient strategies; (ii application of seasonal energy-efficient strategies; (iii analysis of energy saving effect by season; and (iv life cycle cost and life cycle CO2 analyses for selecting an optimal DSF. Results show that a shaft box DSF energy model (EMS #2, which applied winter strategies, was optimal with an energy saving rate of 4.13%, while a multi-story DSF energy model (EMM #5, which applied summer strategies, was optimal with an energy saving rate of 12.67%. In terms of savings to investment ratio (SIR40 and breakeven point (BEP40, the multi-story DSF (3.20; 9 years was superior. The results of this study can be used for (i seasonal energy efficiency strategies of a DSF in East Asian monsoon climates, and (ii as a guideline for the application of a DSF both in existing and new buildings.

  15. Sensitivity studies on the impacts of Tibetan Plateau snowpack pollution on the Asian hydrological cycle and monsoon climate

    Directory of Open Access Journals (Sweden)

    Y. Qian

    2010-10-01

    Full Text Available The Tibetan Plateau (TP, the highest and largest plateau in the world, has long been identified to be critical in regulating the Asian monsoon climate and hydrological cycle. The snowpack and glaciers over the TP provide fresh water to billions of people in Asian countries, but the TP glaciers have been retreating faster than those anywhere else in the world. In this modeling study a series of numerical experiments with a global climate model are designed to simulate radiative forcing of black carbon (BC and dust in snow, and to assess the relative impacts of anthropogenic CO2 and carbonaceous particles in the atmosphere and snow on the snowpack over the TP and subsequent impacts on the Asian monsoon climate and hydrological cycle. Simulations results show a large BC content in snow over the TP, especially the southern slope, with concentration larger than 100 μg/kg. Because of the high aerosol content in snow and large incident solar radiation in the low latitude and high elevation, the TP exhibits the largest surface radiative forcing induced by aerosols (e.g. BC, Dust in snow compared to other snow-covered regions in the world.

    Simulation results show that the aerosol-induced snow albedo perturbations generate surface radiative forcing of 5–25 W m−2 during spring, with a maximum in April or May. BC-in-snow increases the surface air temperature by around 1.0 °C averaged over the TP and reduces spring snowpack over the TP more than pre-industrial to present CO2 increase and carbonaceous particles in the atmosphere. As a result, runoff increases during late winter and early spring but decreases during late spring and early summer (i.e. a trend toward earlier melt dates. The snowmelt efficacy, defined as the snowpack reduction per unit degree of warming induced by the forcing agent, is 1–4 times larger for BC-in-snow than CO2 increase during April–July, indicating that BC-in-snow more

  16. Science Matters Podcast: Climate Change Research

    Science.gov (United States)

    Listen to a podcast with Dr. Andy Miller, the Associate Director for Climate for the Agency's Air, Climate, and Energy Research Program, as he answers questions about climate change research, or read some of the highlights from the conversation here.

  17. Predicting Monsoonal-Driven Stream Discharge and Sediment Yield in Himalaya Mountain Basins with Changing Climate and Deforestation

    Science.gov (United States)

    Neupane, R. P.; White, J. D.

    2014-12-01

    Short and long term effects of site water availability impacts the spectrum of management outcomes including landslide risk, hydropower generation, and sustainable agriculture in mountain systems heavily influenced by climate and land use changes. Climate change and land use may predominantly affect the hydrologic cycle of mountain basins as soil precipitation interception is affected by land cover. Using the Soil and Water Assessment Tool, we estimated stream discharge and sediment yield associated with climate and land use changes for two Himalaya basins located at eastern and western margins of Nepal that included drainages of the Tamor and Seti Rivers. Future climate change was modeled using average output of temperature and precipitation changes derived from Special Report on Emission Scenarios (B1, A1B & A2) of 16 global circulation models for 2080 as meteorological inputs into SWAT. Land use change was modeled spatially and included 1) deforestation, 2) expansion of agricultural land, and 3) increased human settlement that were produced by considering current land use with projected changes associated with viability of elevation and slope characteristics of the basins capable of supporting different land use types. We found higher annual stream discharge in all GCM-derived scenarios compared to the baseline with maximum increases of 13 and 8% in SRES-A2 and SRES-A1B for the Tamor and Seti basins, respectively. With 7% of original forest land removed, sediment yield for Tamor basin was estimated to be 65% higher, but increased to 124% for the SRES-B1 scenario. For the Seti basin, 4% deforestation yielded 33% more sediment for the SRES-A1B scenario. Our results indicated that combined effects of future, intensified monsoon rainfall with deforestation lead to dramatic potential for increased stream discharge and sediment yield as rainfall on steep slopes with thin exposed soils increases surface runoff and soil erosion in the Himalayas. This effect appears to

  18. Climate strength: a new direction for climate research.

    Science.gov (United States)

    Schneider, Benjamin; Salvaggio, Amy Nicole; Subirats, Montse

    2002-04-01

    Climate strength was conceptualized within D. Chan's (1998) discussion of compositional models and the concept of culture strength from the organizational culture literature. Climate strength was operationalized in terms of within-group variability in climate perceptions-the less within-group variability, the stronger the climate. The authors studied climate strength in the context of research linking employee service climate perceptions to customer satisfaction. The hypothesis was tested that climate strength moderates the relationship between employee perceptions of service climate and customer satisfaction experiences. Partial support for the hypothesis was reported in both a concurrent and predictive (3-year) test across 118 branches of a bank. In the predictive study only the interaction of climate and climate strength predicted customer satisfaction. Implications for future research on climate and climate strength are discussed.

  19. Water Vapor Transport and Cross-Equatorial Flow over the Asian-Australia Monsoon Region Simulated by CMIP5 Climate Models

    Institute of Scientific and Technical Information of China (English)

    SONG Yajuan; QIAO Fangli; SONG Zhenya; JIANG Chunfei

    2013-01-01

    The summer mean water vapor transport (WVT) and cross-equatorial flow (CEF) over the AsianAustralian monsoon region simulated by 22 coupled atmospheric-oceanic general circulation models (AOGCMs)from the World Climate Research Programme's Coupled Model Intercomparison Project Phase 5 (CMIP5)were evaluated.Based on climatology of the twentieth-century simulations,most of models have a reasonably realistic representation of summer monsoon WVT characterized by southeast water vapor conveyor belt over the South Indian Ocean and southwest belt from the Arabian Sea to the East Asian.The correlation coefficients between NCEP reanalysis and simulations of BCC-CSM1-1,BNU-ESM,CanESM2,FGOALS-s2,MIROC4h and MPI-ESM-LR are up to 0.8.The simulated CEF depicted by the meridional wind along the equator includes the Somali jet and eastern CEF in low atmosphere and the reverse circulation in upper atmosphere,which were generally consistent with NCEP reanalysis.Multi-model ensemble means (MME) can reproduce more reasonable climatological features in spatial distribution both of WVT and CEF.Ten models with more reasonable WVT simulations were selected for future projection studies,including BCCCSM1-1,BNU-ESM,CanESM2,CCSM4,FGOALS-s2,FIO-ESM,GFDL-ESM2G,MRIOC5,MPI-ESM-LR and NorESM-1M.Analysis based on the future projection experiments in RCP (Representative Concentration Pathway) 2.6,RCP4.5,RCP6 and RCP8.5 show that the global warming forced by different RCP scenarios will results in enhanced WVT over the Indian area and the west Pacific and weaken WVT in the low latitudes of tropical Indian Ocean.

  20. Parametric Sensitivity Analysis for the Asian Summer Monsoon Precipitation Simulation in the Beijing Climate Center AGCM Version 2.1

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ben; Zhang, Yaocun; Qian, Yun; Wu, Tongwen; Huang, Anning; Fang, Yongjie

    2015-07-15

    In this study, we apply an efficient sampling approach and conduct a large number of simulations to explore the sensitivity of the simulated Asian summer monsoon (ASM) precipitation, including the climatological state and interannual variability, to eight parameters related to the cloud and precipitation processes in the Beijing Climate Center AGCM version 2.1 (BCC_AGCM2.1). Our results show that BCC_AGCM2.1 has large biases in simulating the ASM precipitation. The precipitation efficiency and evaporation coefficient for deep convection are the most sensitive parameters in simulating the ASM precipitation. With optimal parameter values, the simulated precipitation climatology could be remarkably improved, e.g. increased precipitation over the equator Indian Ocean, suppressed precipitation over the Philippine Sea, and more realistic Meiyu distribution over Eastern China. The ASM precipitation interannual variability is further analyzed, with a focus on the ENSO impacts. It shows the simulations with better ASM precipitation climatology can also produce more realistic precipitation anomalies during El Niño decaying summer. In the low-skill experiments for precipitation climatology, the ENSO-induced precipitation anomalies are most significant over continents (vs. over ocean in observation) in the South Asian monsoon region. More realistic results are derived from the higher-skill experiments with stronger anomalies over the Indian Ocean and weaker anomalies over India and the western Pacific, favoring more evident easterly anomalies forced by the tropical Indian Ocean warming and stronger Indian Ocean-western Pacific tele-connection as observed. Our model results reveal a strong connection between the simulated ASM precipitation climatological state and interannual variability in BCC_AGCM2.1 when key parameters are perturbed.

  1. South Asian climate change at the end of urban Harappan (Indus valley) civilization and mechanisms of Holocene monsoon variability

    Science.gov (United States)

    Staubwasser, M.; Sirocko, F.; Erlenkeuser, H.; Grootes, P. M.; Segl, M.

    2003-04-01

    Planktonic oxygen isotope ratios from the well-dated laminated sediment core 63KA off the river Indus delta are presented. The record reveals significant climate changes in the south Asian monsoon system throughout the Holocene. The most prominent event of the early-mid Holocene occurred after 8.4 ka BP and is within dating error of the GISP/GRIP event centered at 8.2 ka BP. The late Holocene is generally more variable and the largest change of the entire Holocene occurred at 4.2 ka BP. This event is concordant with the end of urban Harappan civilization in the Indus valley. Opposing isotopic trends across the northern Arabian Sea surface indicate a reduction in Indus river discharge at that time. Consequently, sustained drought may have initiated the archaeologically recorded interval of southeastward habitat tracking within the Harappan cultural domain. The hemispheric significance of the 4.2 ka BP event is evident from concordant climate change in the eastern Mediterranean and the Middle East. The remainder of the late Holocene shows drought cycles of approximately 700 years that are coherent with the evolution of cosmogenic radiocarbon production rates in the atmosphere. This suggests that solar variability is one fundamental cause behind late Holocene rainfall changes over south Asia.

  2. Decadal shifts of East Asian summer monsoon in a climate model free of explicit GHGs and aerosols

    Science.gov (United States)

    Lin, Renping; Zhu, Jiang; Zheng, Fei

    2016-12-01

    The East Asian summer monsoon (EASM) experienced decadal transitions over the past few decades, and the associated "wetter-South-drier-North" shifts in rainfall patterns in China significantly affected the social and economic development in China. Two viewpoints stand out to explain these decadal shifts, regarding the shifts either a result of internal variability of climate system or that of external forcings (e.g. greenhouse gases (GHGs) and anthropogenic aerosols). However, most climate models, for example, the Atmospheric Model Intercomparison Project (AMIP)-type simulations and the Coupled Model Intercomparison Project (CMIP)-type simulations, fail to simulate the variation patterns, leaving the mechanisms responsible for these shifts still open to dispute. In this study, we conducted a successful simulation of these decadal transitions in a coupled model where we applied ocean data assimilation in the model free of explicit aerosols and GHGs forcing. The associated decadal shifts of the three-dimensional spatial structure in the 1990s, including the eastward retreat, the northward shift of the western Pacific subtropical high (WPSH), and the south-cool-north-warm pattern of the upper-level tropospheric temperature, were all well captured. Our simulation supports the argument that the variations of the oceanic fields are the dominant factor responsible for the EASM decadal transitions.

  3. The middle Holocene climatic records from Arabia: Reassessing lacustrine environments, shift of ITCZ in Arabian Sea, and impacts of the southwest Indian and African monsoons

    Science.gov (United States)

    Enzel, Yehouda; Kushnir, Yochanan; Quade, Jay

    2015-06-01

    A dramatic increase in regional summer rainfall amount has been proposed for the Arabian Peninsula during the middle Holocene (ca. 9-5 ka BP) based on lacustrine sediments, inferred lake levels, speleothems, and pollen. This rainfall increase is considered primarily the result of an intensified Indian summer monsoon as part of the insolation-driven, northward shift of the boreal summer position of the Inter-Tropical Convergence Zone (ITCZ) to over the deserts of North Africa, Arabia, and northwest India. We examine the basis for the proposed drastic climate change in Arabia and the shifts in the summer monsoon rains, by reviewing paleohydrologic lacustrine records from Arabia. We evaluate and reinterpret individual lake-basin status regarding their lacustrine-like deposits, physiography, shorelines, fauna and flora, and conclude that these basins were not occupied by lakes, but by shallow marsh environments. Rainfall increase required to support such restricted wetlands is much smaller than needed to form and maintain highly evaporating lakes and we suggest that rainfall changes occurred primarily at the elevated edges of southwestern, southern, and southeastern Arabian Peninsula. These relatively small changes in rainfall amounts and local are also supported by pollen and speleothems from the region. The changes do not require a northward shift of the Northern Hemisphere summer ITCZ and intensification of the Indian monsoon rainfall. We propose that (a) latitudinal and slight inland expansion of the North African summer monsoon rains across the Red Sea, and (b) uplifted moist air of this monsoon to southwestern Arabia highlands, rather than rains associated with intensification of Indian summer monsoon, as proposed before, increased rains in that region; these African monsoon rains produced the modest paleo-wetlands in downstream hyperarid basins. Furthermore, we postulate that as in present-day, the ITCZ in the Indian Ocean remained at or near the equator all

  4. Synchronicity of the East Asian Summer Monsoon variability and Northern Hemisphere climate change since the last deglaciation

    Directory of Open Access Journals (Sweden)

    T. Shinozaki

    2011-06-01

    Full Text Available Understanding of the mechanism of the East Asian Summer Monsoon (EASM is required for the prediction of climate change in East Asia in a scenario of modern global warming. In this study, we present high-resolution climate records from peat sediments in Northeast Japan to reconstruct the EASM variability based on peat bulk cellulose δ13C since the last deglaciation. We used a 8.8 m long peat sediment core collected from the Tashiro Bog, Northeast Japan. Based on 42 14C measurements, the core bottom reaches ~15.5 ka. δ13C, accumulation rate and accumulation flux time-series correlate well to Greenland ice core δ18O variability, suggesting that the climate record in Northeast Japan is linked to global climate changes. The δ13C record at Tashiro Bog and other paleo-EASM records at Northeast and Southern China consistently demonstrate that hydrological environments were spatially different in mid-high and mid-low latitude regions over the last 15.5 kyr. During global cooling (warming periods, mid-high and mid-low latitude regions were characterized by wet (dry and dry (wet environments, respectively. We suggest that these climatic patterns are related to the migration of the EASM-related rain belt during global climate changes, as a consequence of variations in intensity and location of both the Intertropical Convergence Zone (ITCZ and the Western Pacific Subtropical High (STH. The location of the rain belt largely influences the East Asian hydrological environment. Our δ13C time-series are characterized by a 1230 yr throughout the Holocene and a 680 yr periodicity during the early Holocene. The 1230 yr periodicity is in agreement with North Atlantic ice-rafted debris (IRD events, suggesting a teleconnection between the Northeast Japan and the North Atlantic during the Holocene. In addition, it is the first evidence that the Bond events were recorded in terrestrial sediment in

  5. Climate Change Communication Research: Trends and Implications ...

    African Journals Online (AJOL)

    Climate Change Communication Research: Trends and Implications. ... journal articles in the areas communication, climate change and agriculture. ... climate change communication to farmers have been purely elitist and quantitative, which ...

  6. Application of regional climate models to the Indian winter monsoon over the western Himalayas.

    Science.gov (United States)

    Dimri, A P; Yasunari, T; Wiltshire, A; Kumar, P; Mathison, C; Ridley, J; Jacob, D

    2013-12-01

    The Himalayan region is characterized by pronounced topographic heterogeneity and land use variability from west to east, with a large variation in regional climate patterns. Over the western part of the region, almost one-third of the annual precipitation is received in winter during cyclonic storms embedded in westerlies, known locally as the western disturbance. In the present paper, the regional winter climate over the western Himalayas is analyzed from simulations produced by two regional climate models (RCMs) forced with large-scale fields from ERA-Interim. The analysis was conducted by the composition of contrasting (wet and dry) winter precipitation years. The findings showed that RCMs could simulate the regional climate of the western Himalayas and represent the atmospheric circulation during extreme precipitation years in accordance with observations. The results suggest the important role of topography in moisture fluxes, transport and vertical flows. Dynamical downscaling with RCMs represented regional climates at the mountain or even event scale. However, uncertainties of precipitation scale and liquid-solid precipitation ratios within RCMs are still large for the purposes of hydrological and glaciological studies. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Climatic control on extreme sediment transfer from Dokriani Glacier during monsoon, Garhwal Himalaya (India)

    Science.gov (United States)

    Kumar, Amit; Verma, Akshaya; Dobhal, Dwarika Prasad; Mehta, Manish; Kesarwani, Kapil

    2014-02-01

    In the Himalayas, most of the glaciers are covered by thick debris, especially in the ablation zone. Supraglacial debris cover might play an important role for sediment budget of the glaciated area or for the ablation of ice masses mantled in debris. During summer season, proglacial meltwater carries considerable amount of suspended sediment. The deglaciated area provides a ready source of sediment during Indian Summer Monsoon (ISM). The heavy sediment load from the glaciers affects the hydropower generation, irrigation and drinking water supply. Therefore, to understand the sediment delivery from glaciated basins, characteristics and variation of the suspended sediment concentrations in the proglacial meltwater stream, Dokriani Glacier, have been monitored during the ablation season (May-September). Suspended sediment samples were collected near the snout of Dokriani Glacier, Garhwal Himalaya, in 2010 and 2011. Results show that mean monthly suspended sediment concentrations (SSC) were 1499, 2303, 3845 and 1649 mg/l for the months June, July, August, and September, respectively, indicating highest concentration in August followed by July. Over the period of recording, daily mean suspended concentration in the melt stream varied from 13-9798.2 mg/l, which is very high, caused due to a flash flood event during the monitoring period. The mean daily suspended sediment concentration was computed to be 2196 mg/l. The suspended sediment concentration begins to increase with discharge from May and reduces in September. Present study provides TRMM (Tropical Rainfall Measuring Mission) derived and field based hydro-meteorological insight about severe rainstorms during the years 2010 and 2011 in the study area, which transported large amounts of sediment.

  8. Climatic control on extreme sediment transfer from Dokriani Glacier during monsoon, Garhwal Himalaya (India)

    Indian Academy of Sciences (India)

    Amit Kumar; Akshaya Verma; Dwarika Prasad Dobhal; Manish Mehta; Kapil Kesarwani

    2014-02-01

    In the Himalayas, most of the glaciers are covered by thick debris, especially in the ablation zone. Supraglacial debris cover might play an important role for sediment budget of the glaciated area or for the ablation of ice masses mantled in debris. During summer season, proglacial meltwater carries considerable amount of suspended sediment. The deglaciated area provides a ready source of sediment during Indian Summer Monsoon (ISM). The heavy sediment load from the glaciers affects the hydropower generation, irrigation and drinking water supply. Therefore, to understand the sediment delivery from glaciated basins, characteristics and variation of the suspended sediment concentrations in the proglacial meltwater stream, Dokriani Glacier, have been monitored during the ablation season (May– September). Suspended sediment samples were collected near the snout of Dokriani Glacier, Garhwal Himalaya, in 2010 and 2011. Results show that mean monthly suspended sediment concentrations (SSC) were 1499, 2303, 3845 and 1649 mg/l for the months June, July, August, and September, respectively, indicating highest concentration in August followed by July. Over the period of recording, daily mean suspended concentration in the melt stream varied from 13–9798.2 mg/l, which is very high, caused due to a flash flood event during the monitoring period. The mean daily suspended sediment concentration was computed to be 2196 mg/l. The suspended sediment concentration begins to increase with discharge from May and reduces in September. Present study provides TRMM (Tropical Rainfall Measuring Mission) derived and field based hydro-meteorological insight about severe rainstorms during the years 2010 and 2011 in the study area, which transported large amounts of sediment.

  9. Abrupt climate change of East Asian Monsoon at 130 kaBP inferred from a high resolution stalagmite δ18O record

    Institute of Scientific and Technical Information of China (English)

    JIANG Xiuyang; WANG Yongjin; KONG Xinggong; WU Jiangying; SHAO Xiaohua; XIA Zhifeng; CHENG Hai

    2005-01-01

    230Th ages and oxygen isotope data of a stalagmite from Shanbao Cave in Hubei Province characterize the East Asian Monsoon precipitation from 133 to127 ka. The decadal-scale high-resolution δ18O record reveals a detailed transitional process from the Penultimate Glaciation to the Last Interglaciation. As established with 230Th dates, the age of the Termination II is determined to be 129.5±1.0 kaBP, which supports the Northern Hemisphere insolation as the triggers for the ice-age cycles. In our δ18O record, the glacial/ interglacial fluctuation reaches about 4‰, almost the same level as in other Asian Monsoon cave stalagmite δ18O records. The transition of the glacial/interglacial period in our record can be recognized as four stepwise stages, among which, a rapid rise of monsoon precipitation follows the stage of "Termination II pause". The rapid rise is synchronous with the abrupt change of global methane concentration, which reflects that an increase in both Asian Monsoon precipitation and tropical wetland plays an important role in the global climate changes.

  10. Influence of upper ocean on Indian summer monsoon rainfall: studies by observation and NCEP climate forecast system (CFSv2)

    Science.gov (United States)

    Chaudhari, Hemantkumar S.; Pokhrel, Samir; Rahman, H.; Dhakate, A.; Saha, Subodh K.; Pentakota, S.; Gairola, R. M.

    2016-08-01

    This study explores the role played by ocean processes in influencing Indian summer monsoon rainfall (ISMR) and compares the observed findings with National Centers for Environmental Prediction (NCEP)-coupled model Climate Forecast System, version 2 (CFSv2). The excess and deficit ISMR clearly brings out the distinct signatures in sea surface height (SSH) anomaly, thermocline and mixed layer depth over north Indian Ocean. CFSv2 is successful in simulating SSH anomalies, especially over Arabian Sea and Bay of Bengal region. CFSv2 captures observed findings of SSH anomalies during flood and drought (e.g., Rossby wave propagation which reaches western Bay of Bengal (BoB) during flood years, Rossby wave propagation which did not reach western BoB during drought). It highlights the ability of CFSv2 to simulate the basic ocean processes which governs the SSH variability. These differences are basically generated by upwelling and downwelling caused by the equatorial and coastal Kelvin and Rossby waves, thereby causing difference in SSH anomaly and thermocline, and subsequently modifying the convection centers, which dictates precipitation over the Indian subcontinent region. Since the observed SSH anomaly and thermal structure show distinct characteristic features with respect to strong and weak ISMR variability, the assimilation of real ocean data in terms of satellite products (like SSHA from AVISO/SARAL) bestow great promise for the future improvement.

  11. Terrestrial selenium distribution in China is potentially linked to monsoonal climate

    NARCIS (Netherlands)

    Blazina, T.; Sun, Y.; Voegelin, A.; Lenz, M.; Berg, M.; Winkel, L.H.E.

    2014-01-01

    The prevalence of terrestrial environments low in the essential trace element selenium (Se) results in large-scale Se deficiency worldwide. However, the underlying processes leading to Se-depleted environments have remained elusive. Here we show that over the last 6.8 million years (Ma) climatic fac

  12. Terrestrial selenium distribution in China is potentially linked to monsoonal climate

    NARCIS (Netherlands)

    Blazina, T.; Sun, Y.; Voegelin, A.; Lenz, M.; Berg, M.; Winkel, L.H.E.

    2014-01-01

    The prevalence of terrestrial environments low in the essential trace element selenium (Se) results in large-scale Se deficiency worldwide. However, the underlying processes leading to Se-depleted environments have remained elusive. Here we show that over the last 6.8 million years (Ma) climatic fac

  13. Investigation of dominant hydrological processes in a tropical catchment in a monsoonal climate via the downward approach

    Science.gov (United States)

    Montanari, L.; Sivapalan, M.; Montanari, A.

    2006-10-01

    This study explores the dominant processes that may be responsible for the observed streamflow response in Seventeen Mile Creek, a tropical catchment located in a monsoonal climate in Northern Territory, Australia. The hydrology of this vast region of Australia is poorly understood due to the low level of information and gauging that are available. Any insights that can be gained from the few well gauged catchments that do exist can be valuable for predictions and water resource assessments in other poorly gauged or ungauged catchments in the region. To this end, the available rainfall and runoff data from Seventeen Mile Creek catchment are analyzed through the systematic and progressive development and testing of rainfall-runoff models of increasing complexity, by following the "downward" or "top-down" approach. This procedure resulted in a multiple bucket model (4 buckets in parallel). Modelling results suggest that the catchment's soils and the landscape in general have a high storage capacity, generating a significant fraction of delayed runoff, whereas saturation excess overland flow occurs only after heavy rainfall events. The sensitivity analyses carried out with the model with regard to soil depth and temporal rainfall variability revealed that total runoff from the catchment is more sensitive to rainfall variations than to soil depth variations, whereas the partitioning into individual components of runoff appears to be more influenced by soil depth variations. The catchment exhibits considerable inter-annual variability in runoff volumes and the greatest determinant of this variability turns out to be the seasonality of the climate, the timing of the wet season, and temporal patterns of the rainfall. The water balance is also affected by the underlying geology, nature of the soils and the landforms, and the type, density and dynamics of vegetation, although information pertaining to these is lacking.

  14. Investigation of dominant hydrological processes in a tropical catchment in a monsoonal climate via the downward approach

    Directory of Open Access Journals (Sweden)

    L. Montanari

    2006-01-01

    Full Text Available This study explores the dominant processes that may be responsible for the observed streamflow response in Seventeen Mile Creek, a tropical catchment located in a monsoonal climate in Northern Territory, Australia. The hydrology of this vast region of Australia is poorly understood due to the low level of information and gauging that are available. Any insights that can be gained from the few well gauged catchments that do exist can be valuable for predictions and water resource assessments in other poorly gauged or ungauged catchments in the region. To this end, the available rainfall and runoff data from Seventeen Mile Creek catchment are analyzed through the systematic and progressive development and testing of rainfall-runoff models of increasing complexity, by following the "downward" or "top-down" approach. This procedure resulted in a multiple bucket model (4 buckets in parallel. Modelling results suggest that the catchment's soils and the landscape in general have a high storage capacity, generating a significant fraction of delayed runoff, whereas saturation excess overland flow occurs only after heavy rainfall events. The sensitivity analyses carried out with the model with regard to soil depth and temporal rainfall variability revealed that total runoff from the catchment is more sensitive to rainfall variations than to soil depth variations, whereas the partitioning into individual components of runoff appears to be more influenced by soil depth variations. The catchment exhibits considerable inter-annual variability in runoff volumes and the greatest determinant of this variability turns out to be the seasonality of the climate, the timing of the wet season, and temporal patterns of the rainfall. The water balance is also affected by the underlying geology, nature of the soils and the landforms, and the type, density and dynamics of vegetation, although information pertaining to these is lacking.

  15. Summer monsoon circulation and precipitation over the tropical Indian Ocean during ENSO in the NCEP climate forecast system

    Science.gov (United States)

    Chowdary, J. S.; Chaudhari, H. S.; Gnanaseelan, C.; Parekh, Anant; Suryachandra Rao, A.; Sreenivas, P.; Pokhrel, S.; Singh, P.

    2014-04-01

    This study investigates the El Niño Southern Oscillation (ENSO) teleconnections to tropical Indian Ocean (TIO) and their relationship with the Indian summer monsoon in the coupled general circulation model climate forecast system (CFS). The model shows good skill in simulating the impact of El Niño over the Indian Oceanic rim during its decay phase (the summer following peak phase of El Niño). Summer surface circulation patterns during the developing phase of El Niño are more influenced by local Sea Surface Temperature (SST) anomalies in the model unlike in observations. Eastern TIO cooling similar to that of Indian Ocean Dipole (IOD) is a dominant model feature in summer. This anomalous SST pattern therefore is attributed to the tendency of the model to simulate more frequent IOD events. On the other hand, in the model baroclinic response to the diabatic heating anomalies induced by the El Niño related warm SSTs is weak, resulting in reduced zonal extension of the Rossby wave response. This is mostly due to weak eastern Pacific summer time SST anomalies in the model during the developing phase of El Niño as compared to observations. Both eastern TIO cooling and weak SST warming in El Niño region combined together undermine the ENSO teleconnections to the TIO and south Asia regions. The model is able to capture the spatial patterns of SST, circulation and precipitation well during the decay phase of El Niño over the Indo-western Pacific including the typical spring asymmetric mode and summer basin-wide warming in TIO. The model simulated El Niño decay one or two seasons later, resulting long persistent warm SST and circulation anomalies mainly over the southwest TIO. In response to the late decay of El Niño, Ekman pumping shows two maxima over the southern TIO. In conjunction with this unrealistic Ekman pumping, westward propagating Rossby waves display two peaks, which play key role in the long-persistence of the TIO warming in the model (for more than a

  16. Shifting covariability of North American summer monsoon precipitation with antecedent winter precipitation

    Science.gov (United States)

    McCabe, G.J.; Clark, M.P.

    2006-01-01

    Previous research has suggested that a general inverse relation exists between winter precipitation in the southwestern United states (US) and summer monsoon precipitation. In addition, it has been suggested that this inverse relation between winter precipitation and the magnitude of the southwestern US monsoon breaks down under certain climatic conditions that override the regional winter/monsoon precipitation relations. Results from this new study indicate that the winter/monsoon precipitation relations do not break down, but rather shift location through time. The strength of winter/monsoon precipitation relations, as indexed by 20-year moving correlations between winter precipitation and monsoon precipitation, decreased in Arizona after about 1970, but increased in New Mexico. The changes in these correlations appear to be related to an eastward shift in the location of monsoon precipitation in the southwestern US. This eastward shift in monsoon precipitation and the changes in correlations with winter precipitation also appear to be related to an eastward shift in July/August atmospheric circulation over the southwestern US that resulted in increased monsoon precipitation in New Mexico. Results also indicate that decreases in sea-surface temperatures (SSTs) in the central North Pacific Ocean also may be associated with th changes in correlations between winter and monsoon precipitation. Copyright ?? 2006 Royal Meteorological Society.

  17. Reply to 'Influence of cosmic ray variability on the monsoon rainfall and temperature': a false-positive in the field of solar-terrestrial research

    CERN Document Server

    Laken, Benjamin A

    2015-01-01

    A litany of research has been published claiming strong solar influences on the Earth's weather and climate. Much of this work includes documented errors and false-positives, yet is still frequently used to substantiate arguments of global warming denial. This manuscript reports on a recent study by Badruddin & Aslam (2014), hereafter BA14, which claimed a highly significant ($p=1.4\\times10^{-5}$) relationship between extremes in the intensity of the Indian monsoon and the cosmic ray flux. They further speculated that the relationship they observed may apply across the entire tropical and sub-tropical belt, and be of global importance. However, their statistical analysis---and consequently their conclusions---were wrong. Specifically, their error resulted from an assumption that their data's underlying distribution was Gaussian. But, as demonstrated in this work, their data closely follow an ergodic chaotic distribution biased towards extreme values. From a probability density function, calculated using a...

  18. Mangrove forest degradation indicated by mangrove-derived organic matter in the Qinzhou Bay, Guangxi, China, and its response to the Asian monsoon during the Holocene climatic optimum

    Institute of Scientific and Technical Information of China (English)

    MENG Xianwei; XIA Peng; LI Zhen; LIU Lejun

    2016-01-01

    The response of mangrove ecosystems to the Asian monsoon in the future global warming can be understood by reconstructing the development of mangrove forests during the Holocene climatic optimum (HCO), using proxies preserved in coastal sediments. The total organic matter in sediments of a segmented core, with calibrated age ranges between 5.6 and 7.7 cal. ka BP and corresponding to the HCO, from the Qinzhou Bay in Guangxi, China, is quantitatively partitioned into three end-members according to their sources: mangrove-derived, terrigenous, and marine phytoplanktonic, using a three-end-member model depicted by organic carbon isotope (δ13Corg) and the molar ratio of total organic carbon to total nitrogen (C/N). The percentage of mangrove-derived organic matter (MOM) contribution is used as a proxy for mangrove development. Three visible drops in MOM contribution occurred at ca. 7.3, ca. 6.9, and ca. 6.2 cal. ka BP, respectively, are recognized against a relatively stable and higher MOM contribution level, indicating that three distinct mangrove forest degradations occurred in the Qinzhou Bay during the HCO. The three mangrove forest degradations approximately correspond to the time of the strengthened/weakened Asian winter/summer monsoon. This indicates that even during a period favorable for the mangrove development, such as the HCO, climatic extremes, such as cold and dry events driven by the strengthened/weakened Asian winter/summer monsoon, can trigger the degradation of mangrove forests.

  19. Abrupt Holocene changes of the Asian monsoon at millen-nial- and centennial-scales:Evidence from lake sediment document in Minqin Basin,NW China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Considerable research is now focusing on abrupt Holocene changes at millennial- and centennial-scales all over the world. This study shows that the changes in the Holocene summer monsoon can be divided into two main periods, based on climatic proxy records of lake sediments from the Sanjiaocheng section located at the NW boundary of the summer monsoon, Gansu Province. The early and middle Holocene was humid with stronger summer monsoon, while the late Holocene is dry with weak summer monsoon. Detailed results also show a series of millennial- and centennial-scale changes in the intensity of the summer monsoon, with a periodicity of 1600 years during the whole Holocene, and with a periodicity of 800 years during the early Holocene. Ten dry events during the Holocene are associated with the weakening of the summer monsoon. These rapid climatic changes may be representative of a global climatic change pattern during the Holocene.

  20. Contrasting sedimentation patterns in two semi-enclosed mesotidal bays along the west and south coasts of Korea controlled by their orientation to the regional monsoon climate

    Science.gov (United States)

    Hong, Seok Hwi; Chun, Seung Soo; Chang, Tae Soo; Jang, Dae Geon

    2017-08-01

    Sedimentation patterns of tidal flats along the Korean west coast have long been known to be largely controlled by the monsoon climate. On the other hand, much less is known about the effect of the monsoon on sedimentation in coastal embayments with mouths of different geographic orientations. Good examples are Hampyeong and Yeoja bays along the west and south coasts, respectively. Both have narrow entrances, but their mouths open toward the northwest and the south, respectively. With mean tidal ranges of 3.46 and 3.2 m, respectively, the two bays experience similar tidal regimes and are hence excellent candidates to compare the effect of different exposure to the same regional monsoon climate on their respective sediment distribution patterns. The winter monsoon, in particular, is characterized by strong northwesterly winds that directly impact the west coast, but blow offshore along the south coast. For the purpose of this study, surficial sediment samples were collected from intertidal and subtidal flats of the two bays, both in summer and winter. Grain-size analyses were carried out by sieving (sand fraction) and Sedigraph (mud fraction). In the case of Yeoja Bay, the sediments consist mostly of mud (mean grain sizes of 5.4 to 8.8 phi). Seasonal changes are very subtle, the sediments being slightly coarser in summer when silt-dominated sediments are supplied by two streams to the northern parts of the bay in response to heavy rainfall. With the exception of the deeper tidal channels, Yeoja Bay is characterized by a thick mud blanket the year round, which is modulated by processes associated with the summer monsoon that predominantly blows from the east. Textural parameters suggest severely restricted sediment mixing on the subtidal and intertidal flats, the overall low energy situation preventing sands from reaching the tidal flats. The sediments of Hampyeong Bay, by contrast, are characterized by a distinct shoreward fining trend. Mean grain sizes average

  1. Contrasting sedimentation patterns in two semi-enclosed mesotidal bays along the west and south coasts of Korea controlled by their orientation to the regional monsoon climate

    Science.gov (United States)

    Hong, Seok Hwi; Chun, Seung Soo; Chang, Tae Soo; Jang, Dae Geon

    2016-11-01

    Sedimentation patterns of tidal flats along the Korean west coast have long been known to be largely controlled by the monsoon climate. On the other hand, much less is known about the effect of the monsoon on sedimentation in coastal embayments with mouths of different geographic orientations. Good examples are Hampyeong and Yeoja bays along the west and south coasts, respectively. Both have narrow entrances, but their mouths open toward the northwest and the south, respectively. With mean tidal ranges of 3.46 and 3.2 m, respectively, the two bays experience similar tidal regimes and are hence excellent candidates to compare the effect of different exposure to the same regional monsoon climate on their respective sediment distribution patterns. The winter monsoon, in particular, is characterized by strong northwesterly winds that directly impact the west coast, but blow offshore along the south coast. For the purpose of this study, surficial sediment samples were collected from intertidal and subtidal flats of the two bays, both in summer and winter. Grain-size analyses were carried out by sieving (sand fraction) and Sedigraph (mud fraction). In the case of Yeoja Bay, the sediments consist mostly of mud (mean grain sizes of 5.4 to 8.8 phi). Seasonal changes are very subtle, the sediments being slightly coarser in summer when silt-dominated sediments are supplied by two streams to the northern parts of the bay in response to heavy rainfall. With the exception of the deeper tidal channels, Yeoja Bay is characterized by a thick mud blanket the year round, which is modulated by processes associated with the summer monsoon that predominantly blows from the east. Textural parameters suggest severely restricted sediment mixing on the subtidal and intertidal flats, the overall low energy situation preventing sands from reaching the tidal flats. The sediments of Hampyeong Bay, by contrast, are characterized by a distinct shoreward fining trend. Mean grain sizes average

  2. Impact of high resolution land surface initialization in Indian summer monsoon simulation using a regional climate model

    Indian Academy of Sciences (India)

    C K Unnikrishnan; M Rajeevan; S Vijaya Bhaskara Rao

    2016-06-01

    The direct impact of high resolution land surface initialization on the forecast bias in a regional climatemodel in recent years over Indian summer monsoon region is investigated. Two sets of regional climatemodel simulations are performed, one with a coarse resolution land surface initial conditions and secondone used a high resolution land surface data for initial condition. The results show that all monsoonyears respond differently to the high resolution land surface initialization. The drought monsoon year2009 and extended break periods were more sensitive to the high resolution land surface initialization.These results suggest that the drought monsoon year predictions can be improved with high resolutionland surface initialization. Result also shows that there are differences in the response to the land surfaceinitialization within the monsoon season. Case studies of heat wave and a monsoon depression simulationshow that, the model biases were also improved with high resolution land surface initialization. Theseresults show the need for a better land surface initialization strategy in high resolution regional modelsfor monsoon forecasting.

  3. Sub-seasonal behaviour of Asian summer monsoon under a changing climate: assessments using CMIP5 models

    Science.gov (United States)

    Sooraj, K. P.; Terray, Pascal; Xavier, Prince

    2016-06-01

    Numerous global warming studies show the anticipated increase in mean precipitation with the rising levels of carbon dioxide concentration. However, apart from the changes in mean precipitation, the finer details of daily precipitation distribution, such as its intensity and frequency (so called daily rainfall extremes), need to be accounted for while determining the impacts of climate changes in future precipitation regimes. Here we examine the climate model projections from a large set of Coupled Model Inter-comparison Project 5 models, to assess these future aspects of rainfall distribution over Asian summer monsoon (ASM) region. Our assessment unravels a north-south rainfall dipole pattern, with increased rainfall over Indian subcontinent extending into the western Pacific region (north ASM region, NASM) and decreased rainfall over equatorial oceanic convergence zone over eastern Indian Ocean region (south ASM region, SASM). This robust future pattern is well conspicuous at both seasonal and sub-seasonal time scales. Subsequent analysis, using daily rainfall events defined using percentile thresholds, demonstrates that mean rainfall changes over NASM region are mainly associated with more intense and more frequent extreme rainfall events (i.e. above 95th percentile). The inference is that there are significant future changes in rainfall probability distributions and not only a uniform shift in the mean rainfall over the NASM region. Rainfall suppression over SASM seems to be associated with changes involving multiple rainfall events and shows a larger model spread, thus making its interpretation more complex compared to NASM. Moisture budget diagnostics generally show that the low-level moisture convergence, due to stronger increase of water vapour in the atmosphere, acts positively to future rainfall changes, especially for heaviest rainfall events. However, it seems that the dynamic component of moisture convergence, associated with vertical motion, shows a

  4. SUNYA Regional Climate Model Simulations of East Asia Summer Monsoon: Effects of Cloud Vertical Structure on the Surface Energy Balance

    Directory of Open Access Journals (Sweden)

    Wei Gong and Wei-Chyung Wang

    2007-01-01

    Full Text Available We used the State University of New York at Albany (SUNYA regional climate model to study the effect of cloud vertical distribution in affecting the surface energy balance of the East Asia summer monsoon (EASM. Simulations were conducted for the summers of 1988 and 1989, during which large contrast in the intra-seasonal cloud radiative forcing (CRF was observed at the top of the atmosphere. The model results indicate that both the high and low clouds are persistent throughout the summer months in both years. Because of large cloud water, low clouds significantly reduce the solar radiation flux reaching the surface, which nevertheless still dominate the surface energy balance, accounting for more than 50% of the surface heating. The low clouds also contribute significantly the downward longwave radiation to the surface with values strongly dependent on the cloud base temperature. The presence of low clouds effectively decreases the temperature and moisture gradients near surface, resulting in a substantial decrease in the sensible and latent heat fluxes from surface, which partially compensate the decrease of the net radiative cooling of the surface. For example, in the two days, May 8 and July 11 of 1988, the total cloud cover of 80% is simulated, but the respective low cloud cover (water was 63% (114 gm-2 and 22% (21 gm-2. As a result, the downward solar radiation is smaller by 161 Wm-2 in May 8. On the other hand, the cloud temperature was _ lower, yielding 56 Wm-2 smaller downward longwave radiation. The near surface temperature and gradient is more than _ smaller (and moisture gradient, leading to 21 and 81 Wm-2 smaller sensible heat and latent heat fluxes. It is also demonstrated that the model is capable to reproduce the intraseasonal variation of shortwave CRF, and catches the relationship between total cloud cover and SW CRF. The model results show the dominance of high cloud on the regional mean longwave CRF and low cloud on the intra

  5. The evol ution of coupling of Asian winter monsoon and high latitude climate of Northern Hemisphere——Grain evidence from 8.1 Ma loess-red clay sequence on the Chinese central Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    吕连清; 方小敏; JosephA.Mason; 李吉均; 安芷生

    2001-01-01

    The evolution and driving mechanism of the Asian winter monsoon system are of great importance to understanding the present-day climate. Through high-resolution particle size analysis of the oldest loess-red clay sequence known so far (with a basal age of about 8 Ma) and comparison of the results with oxygen isotope curves from North Atlantic marine sediments, 4 stages of the evolution of the Asian winter monsoon were clearly demonstrated. During the first stage, between about 8.1 and 4.3 Ma, there was no relation between Asian winter monsoon and Northern Hemisphere ice volume and high latitude climate inferred from marine sediments. A weak relation developed during the second stage, about 4.3 to 3.5 Ma. During the third stage (3.5 to 2.6 Ma) an Asian winter monsoon system similar to the present formed, initiating a stronger relation between the winter monsoon and Northern Hemisphere ice volume and high latitude climate. In the final stage (2.6 to 0 Ma) the present Asian winter monsoon system was fortifi

  6. Groundwater and climate change research scoping study

    OpenAIRE

    Jackson, C. R.; Cheetham, M.; Guha, P

    2006-01-01

    This scoping study has reviewed much of the published literature in the field of climate change and groundwater research. Whilst it is not exhaustive with regard to groundwater quality issues, most of the published literature relating to climate change and groundwater resources, particularly in the UK, is covered. Further work is required to identify current research needs relating to the effects of climate change on groundwater quality. The study of the effects of climate chan...

  7. CMIP5 model-simulated onset, duration and intensity of the Asian summer monsoon in current and future climate

    Science.gov (United States)

    Dong, Guangtao; Zhang, H.; Moise, A.; Hanson, L.; Liang, P.; Ye, H.

    2016-01-01

    A number of significant weaknesses existed in our previous analysis of the changes in the Asian monsoon onset/retreat from coupled model intercomparison project phase 3 (CMIP3) models, including a lack of statistical significance tests, a small number of models analysed, and limited understanding of the causes of model uncertainties. Yet, the latest IPCC report acknowledges limited confidence for projected changes in monsoon onset/retreat. In this study we revisit the topic by expanding the analysis to a large number of CMIP5 models over much longer period and with more diagnoses. Daily 850 hPa wind, volumetric atmospheric precipitable water and rainfall data from 26 CMIP5 models over two sets of 50-year periods are used in this study. The overall model skill in reproducing the temporal and spatial patterns of the monsoon development is similar between CMIP3 and CMIP5 models. They are able to show distinct regional characteristics in the evolutions of Indian summer monsoon (ISM), East Asian summer monsoon (EASM) and West North Pacific summer monsoon (WNPSM). Nevertheless, the averaged onset dates vary significantly among the models. Large uncertainty exists in model-simulated changes in onset/retreat dates and the extent of uncertainty is comparable to that in CMIP3 models. Under global warming, a majority of the models tend to suggest delayed onset for the south Asian monsoon in the eastern part of tropical Indian Ocean and Indochina Peninsula and nearby region, primarily due to weakened tropical circulations and eastward shift of the Walker circulation. The earlier onset over the Arabian Sea and part of the Indian subcontinent in a number of the models are related to an enhanced southwesterly flow in the region. Weak changes in other domains are due to the offsetting results among the models, with some models showing earlier onsets but others showing delayed onsets. Different from the analysis of CMIP3 model results, this analysis highlights the importance of SST

  8. A climate change-induced threat to the ecological resilience of a subtropical monsoon evergreen broad-leaved forest in Southern China.

    Science.gov (United States)

    Zhou, Guoyi; Peng, Changhui; Li, Yuelin; Liu, Shizhong; Zhang, Qianmei; Tang, Xuli; Liu, Juxiu; Yan, Junhua; Zhang, Deqiang; Chu, Guowei

    2013-04-01

    Recent studies have suggested that tropical forests may not be resilient against climate change in the long term, primarily owing to predicted reductions in rainfall and forest productivity, increased tree mortality, and declining forest biomass carbon sinks. These changes will be caused by drought-induced water stress and ecosystem disturbances. Several recent studies have reported that climate change has increased tree mortality in temperate and boreal forests, or both mortality and recruitment rates in tropical forests. However, no study has yet examined these changes in the subtropical forests that account for the majority of China's forested land. In this study, we describe how the monsoon evergreen broad-leaved forest has responded to global warming and drought stress using 32 years of data from forest observation plots. Due to an imbalance in mortality and recruitment, and changes in diameter growth rates between larger and smaller trees and among different functional groups, the average DBH of trees and forest biomass have decreased. Sap flow measurements also showed that larger trees were more stressed than smaller trees by the warming and drying environment. As a result, the monsoon evergreen broad-leaved forest community is undergoing a transition from a forest dominated by a cohort of fewer and larger individuals to a forest dominated by a cohort of more and smaller individuals, with a different species composition, suggesting that subtropical forests are threatened by their lack of resilience against long-term climate change.

  9. Orbitally-paced variations of water availability in the SE Asian Monsoon region following the Miocene Climate Transition

    Science.gov (United States)

    Heitmann, Emma O.; Ji, Shunchuan; Nie, Junsheng; Breecker, Daniel O.

    2017-09-01

    Middle Miocene Earth had several boundary conditions similar to those predicted for future Earth including similar atmospheric pCO2 and substantial Antarctic ice cover but no northern hemisphere ice sheets. We describe a 12 m outcrop of the terrestrial Yanwan Section in the Tianshui Basin, Gansu, China, following the Miocene Climate Transition (13.9-13.7 Ma). It consists of ∼25 cm thick CaCO3-cemented horizons that overprint siltstones every ∼1 m. We suggest that stacked soils developed in siltstones under a seasonal climate with a fluctuating water table, evidenced by roots, clay films, mottling, presence of CaCO3 nodules, and stacked carbonate nodule δ13 C and δ18 O profiles that mimic modern soils. We suggest that the CaCO3-cemented horizons are capillary-fringe carbonates that formed in an arid climate with a steady water table and high potential evapotranspiration rates (PET), evidenced by sharp upper and basal contacts, micrite, sparite, and root-pore cements. The CaCO3 of the cemented horizons and the carbonate nodules have similar mean δ18 O and δ13 C values but the cements have significantly smaller variance in δ13 C and δ18 O values and a different δ18 O versus δ13 C slope, supporting the conclusion that these carbonates are from different populations. The magneto-stratigraphic age model indicates obliquity pacing of the arid conditions required to form the CaCO3-cemented horizons suggesting an orbital control on water availability. We suggest two possible drivers for the obliquity pacing of arid conditions: 1) variability in the cross-equatorial pressure gradient that controls summer monsoon (ASM) strength and is influenced by obliquity-paced variations of Antarctic ice volume and 2) variability in Western Pacific Ocean-East Asian continent pressure gradient controlled by the 25-45°N meridional insolation gradient. We also suggest that variations in aridity were influenced by variations in PET and sensible heating of the regional land

  10. Projected changes in South Asian summer monsoon by multi-model global warming experiments

    Science.gov (United States)

    Sabade, S. S.; Kulkarni, Ashwini; Kripalani, R. H.

    2011-03-01

    South Asian summer monsoon (June through September) rainfall simulation and its potential future changes are evaluated in a multi-model ensemble of global coupled climate models outputs under World Climate Research Program Coupled Model Intercomparison Project (WCRP CMIP3) dataset. The response of South Asian summer monsoon to a transient increase in future anthropogenic radiative forcing is investigated for two time slices, middle (2031-2050) and end of the twenty-first century (2081-2100), in the non-mitigated Special Report on Emission Scenarios B1, A1B and A2 .There is large inter-model variability in the simulation of spatial characteristics of seasonal monsoon precipitation. Ten out of the 25 models are able to simulate space-time characteristics of the South Asian monsoon precipitation reasonably well. The response of these selected ten models has been examined for projected changes in seasonal monsoon rainfall. The multi-model ensemble of these ten models projects a significant increase in monsoon precipitation with global warming. The substantial increase in precipitation is observed over western equatorial Indian Ocean and southern parts of India. However, the monsoon circulation weakens significantly under all the three climate change experiments. Possible mechanisms for the projected increase in precipitation and for precipitation-wind paradox have been discussed. The surface temperature over Asian landmass increases in pre-monsoon months due to global warming and heat low over northwest India intensifies. The dipole snow configuration over Eurasian continent strengthens in warmer atmosphere, which is conducive for the enhancement in precipitation over Indian landmass. No notable changes have been projected in the El Niño-Monsoon relationship, which is useful for predicting interannual variations of the monsoon.

  11. Atmospheric Radiation Measurement Climate Research (ARM)

    Data.gov (United States)

    Federal Laboratory Consortium — With heavily instrumented field sites around the globe, the ARM Climate Research Facility provides the world's most comprehensive outdoor laboratory and data archive...

  12. Atmospheric Radiation Measurement Climate Research (ARM)

    Data.gov (United States)

    Federal Laboratory Consortium — With heavily instrumented field sites around the globe, the ARM Climate Research Facility provides the world's most comprehensive outdoor laboratory and data archive...

  13. An Assessment on the Performance of IPCC AR4 Climate Models in Simulating Interdecadal Variations of the East Asian Summer Monsoon

    Institute of Scientific and Technical Information of China (English)

    SUN Ying; DING Yihui

    2008-01-01

    Observations from several data centers together with a categorization method are used to evaluate the IPCC AR4 (Intergovernmental Panel on Climate Change, the Fourth Assessment Report) climate models' performance in simulating the interdecadal variations of summer precipitation and monsoon circulation in East Asia. Out of 19 models under examination, 9 models can relatively well reproduce the 1979-1999 mean June-July-August (JJA) precipitation in East Asia, but only 3 models (Category-1 models) can capture the interdecadal variation of precipitation in East Asia. These 3 models are: GFDL-CM2.0, MIROC3.2 (hires), and MIROC3.2 (medres), among which the GFDL-CM2.0 gives the best performance. The reason for the poor performance of most models in simulating the East Asian summer monsoon interdecadal variation lies in that the key dynamic and thermal-dynamic mechanisms behind the East Asian monsoon change are missed by the models, e.g., the large-scale tropospheric cooling and drying over East Asia. In contrast, the Category-1 models relatively well reproduce the variations in vertical velocity and water vapor over East Asia and thus show a better agreement with observations in simulating the pattern of "wet south and dry north" in China in the past 20 years.It is assessed that a single model's performance in simulating a particular variable has great impacts on the ensemble results. More realistic outputs can be obtained when the multi-model ensemble is carried out using a suite of well-performing models for a specific variable, rather than using all available models. This indicates that although a multi-model ensemble is in general better than a single model, the best ensemble mean cannot be achieved without looking into each member model's performance.

  14. Link between western Arabian sea surface temperature and summer monsoon strength and high-latitude abrupt climate events

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, P.D.

    from Oman and China also show a decrease of monsoon rainfall during the 8.2 cal ka event (Neff et al. 2001; Wang et al. 2005). Similarly, speleothem isotopic record of Costa Rica JOUR.GEOL.SOC.INDIA, VOL.68, SEPT. 2006 LINK BETWEEN WESTERN ARABIAN SEA...

  15. Why do global climate models struggle to represent low-level clouds in the West African summer monsoon?

    Science.gov (United States)

    Knippertz, Peter; Hannak, Lisa; Fink, Andreas H.; Kniffka, Anke; Pante, Gregor

    2017-04-01

    Climate models struggle to realistically represent the West African monsoon (WAM), which hinders reliable future projections and the development of adequate adaption measures. Low-level clouds over southern West Africa (5-10°N, 8°W-8°E) during July-September are an integral part of the WAM through their effect on the surface energy balance and precipitation, but their representation in climate models has so far received little attention. These clouds usually form during the night near the level of the nocturnal low-level jet ( 950 hPa), thicken and spread until the mid-morning ( 09 UTC), and then break up and rise in the course of the day, typically to about 850 hPa. The low thermal contrast to the surface and the frequent presence of obscuring higher-level clouds make detection of the low-level clouds from space rather challenging. Here we use 30 years of output from 18 models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5) as well as 20 years of output from 8 models participating in the Year of Tropical Convection (YoTC) experiments to identify cloud biases and their causes. A great advantage of the YoTC dataset is the 6-hourly output frequency, which allows an analysis of the diurnal cycle, and the availability of temperature and moisture tendencies from parameterized processes such as convection, radiation and boundary-layer turbulence. A comparison to earlier analyses based on CMIP3 output reveals rather limited improvements with regard to the represenation of low-level cloud and winds. Compared to ERA-Interim re-analyses, which shows satisfactory agreement with surface observations, many of the CMIP5 and YoTC models still have large biases in low-level cloudiness of both signs and a tendency to too high elevation and too weak diurnal cycles. At the same time, these models tend to have too strong low-level jets, the impact of which is unclear due to concomitant effects on temperature and moisture advection as well as turbulent

  16. GMMIP (v1.0) contribution to CMIP6: Global Monsoons Model Inter-comparison Project

    OpenAIRE

    Zhou, Tianjun; Turner, Andrew G.; Kinter, James L.; Qian, Yun; Chen, Xiaolong; Bo WU; Wang, Bin; Liu, Bo; Zou, Liwei; He, Bian

    2016-01-01

    The Global Monsoons Model Inter-comparison Project (GMMIP) has been endorsed by the panel of Coupled Model Inter-comparison Project (CMIP) as one of the participating model inter-comparison projects (MIPs) in the sixth phase of CMIP (CMIP6). The focus of GMMIP is on monsoon climatology, variability, prediction and projection, which is relevant to four of the “Grand Challenges” proposed by the World Climate Research Programme. At present, 21 international modeling groups are ...

  17. Gridded daily Indian monsoon rainfall for 14 seasons: Merged TRMM and IMD gauge analyzed values

    Indian Academy of Sciences (India)

    Ashis K Mitra; I M Momin; E N Rajagopal; S Basu; M N Rajeevan; T N Krishnamurti

    2013-10-01

    Indian monsoon is an important component of earth’s climate system. Daily rainfall data for longer period is vital to study components and processes related to Indian monsoon. Daily observed gridded rainfall data covering both land and adjoining oceanic regions are required for numerical model validation and model development for monsoon. In this study, a new gridded daily Indian rainfall dataset at 1° × 1° latitude/longitude resolution covering 14 monsoon seasons (1998–2011) are described. This merged satellite gauge rainfall dataset (NMSG) combines TRMM TMPA rainfall estimates with gauge information from IMD gridded data. Compared to TRMM and GPCP daily rainfall data, the current NMSG daily data has more information due to inclusion of local gauge analysed values. In terms of bias and skill scores this dataset is superior to other daily rainfall datasets. In a mean climatological sense and also for anomalous monsoon seasons, this merged satellite gauge data brings out more detailed features of monsoon rainfall. The difference of NMSG and GPCP looks significant. This dataset will be useful to researchers for monsoon intraseasonal studies and monsoon model development research.

  18. A Bibliometric Analysis of Climate Engineering Research

    Science.gov (United States)

    Belter, C. W.; Seidel, D. J.

    2013-12-01

    The past five years have seen a dramatic increase in the number of media and scientific publications on the topic of climate engineering, or geoengineering, and some scientists are increasingly calling for more research on climate engineering as a possible supplement to climate change mitigation and adaptation strategies. In this context, understanding the current state of climate engineering research can help inform policy discussions and guide future research directions. Bibliometric analysis - the quantitative analysis of publications - is particularly applicable to fields with large bodies of literature that are difficult to summarize by traditional review methods. The multidisciplinary nature of the published literature on climate engineering makes it an ideal candidate for bibliometric analysis. Publications on climate engineering are found to be relatively recent (more than half of all articles during 1988-2011 were published since 2008), include a higher than average percentage of non-research articles (30% compared with 8-15% in related scientific disciplines), and be predominately produced by countries located in the Northern Hemisphere and speaking English. The majority of this literature focuses on land-based methods of carbon sequestration, ocean iron fertilization, and solar radiation management and is produced with little collaboration among research groups. This study provides a summary of existing publications on climate engineering, a perspective on the scientific underpinnings of the global dialogue on climate engineering, and a baseline for quantitatively monitoring the development of climate engineering research in the future.

  19. Non-stationary analysis of dry spells in monsoon season of Senegal River Basin using data from Regional Climate Models (RCMs)

    Science.gov (United States)

    Giraldo Osorio, J. D.; García Galiano, S. G.

    2012-07-01

    SummaryThe Senegal River Basin, located in West Africa, has been affected by several droughts since the end of the 1960s. In its valley, which is densely populated and highly vulnerable to climate variability and water availability, agricultural activities provide the livelihood for thousands of people. Increasing the knowledge about plausible trends of drought events will allow to improve the adaptation and mitigation measures in order to build "adaptive capacity" to climate change in West Africa. An innovative methodology for the non-stationary analysis of droughts events, which allows the prediction of regional trends associated to several return periods, is presented. The analyses were based on Regional Climate Models (RCMs) provided by the European ENSEMBLES project for West Africa, together with observed data. A non-stationary behaviour of the annual series of maximum length of dry spells (AMDSL) in the monsoon season is reflected in temporal changes in mean and variance. The non-stationary nature of hydrometeorological series, due to climate change and anthropogenic activities, is the main criticism to traditional frequency analysis. Therefore, in this paper, the modelling tool GAMLSS (Generalized Additive Models for Location, Scale and Shape), is applied to develop regional probability density functions (pdfs) fitted to AMDSL series for the monsoon season in the Senegal River Basin. The skills of RCMs in the representation of maximum length of dry spells observed for the period 1970-1990, are evaluated considering observed data. Based on the results obtained, a first selection of the RCMs with which to apply GAMLSS to the AMDSL series identified, for the time period 1970-2050, is made. The results of GAMLSS analysis exhibit divergent trends, with different value ranges for parameters of probability distributions being detected. Therefore, in the second stage of the paper, regional pdfs are constructed using bootstrapping distributions based on probabilistic

  20. The Norwegian Climate and Ozone Research Programme

    Energy Technology Data Exchange (ETDEWEB)

    Dahlin, E. [ed.

    1996-03-01

    This report includes abstracts from a workshop arranged by the Norwegian Climate and Ozone Research Programme 11-12 March 1996. The abstracts are organized according to the sessions: (1) Regional effects of climate change with emphasis on ecology, (2) Climate research related to the North Atlantic, (3) What lessons can be drawn from paleoclimatology about changes in the current climate?, (4) Changes in the ozone layer and their effect on UV and biology. Abstracts of a selection of papers presented at the workshop can be found elsewhere in the present data base. 70 refs., 19 figs., 2 tabs.

  1. Gordon Research Conference on Radiation & Climate in 2009, July 5 -10

    Energy Technology Data Exchange (ETDEWEB)

    Quiang Fu

    2009-07-10

    The 2009 Gordon Research Conference on Radiation and Climate will present cutting-edge research on the outstanding issues in global climate change with focus on the radiative forcing and sensitivity of the climate system and associated physical processes. The Conference will feature a wide range of topics, including grand challenges in radiation and climate, radiative forcing, climate feedbacks, cloud processes in climate system, hydrological cycle in changing climate, absorbing aerosols and Asian monsoon, recent climate changes, and geo-engineering. The invited speakers will present the recent most important advances and future challenges in these areas. The Conference will bring together a collection of leading investigators who are at the forefront of their field, and will provide opportunities for scientists especially junior scientists and graduate students to present their work in poster format and exchange ideas with leaders in the field. The collegial atmosphere of this Conference, with programmed discussion sessions as well as opportunities for informal gatherings in the afternoons and evenings, provides an avenue for scientists from different disciplines to brainstorm and promotes cross-disciplinary collaborations in the various research areas represented.

  2. Impacts of warm and cold situations in the Mediterranean basins on the West African monsoon: observed connection patterns (1979-2006) and climate simulations

    Energy Technology Data Exchange (ETDEWEB)

    Fontaine, Bernard; Roucou, Pascal; Sijikumar, Sivarajan [CNRS/University of Burgundy, Centre de Recherches de Climatologie, Dijon (France); Garcia-Serrano, Javier; Rodriguez-Fonseca, Belen; Losada, Teresa [Universidad Complutense de Madrid, Madrid (Spain); Chauvin, Fabrice [CNRS/Meteo-France, Centre National de Recherches Meteorologiques, Toulouse (France); Gervois, Sebastien; Janicot, Serge [CNRS/IRD/Paris VI, Institut Pierre-Simon Laplace/LOCEAN, Paris (France); Ruti, Paolo [Environmental and Energy Research Institute, Rome (Italy)

    2010-07-15

    Using both empirical and numerical ensemble approaches this study focuses on the Mediterranean/West African relationship in northern summer. Statistical analyses utilize skin temperature, sea surface temperature, in situ and satellite rainfall, outgoing longwave radiation (OLR) observations and reanalyzed data winds and specific humidity on isobaric surfaces. Numerical investigations are based on a large set of sensitivity experiments performed on four atmospheric general circulation models (AGCM): ARPEGE-Climat3, ECHAM4, LMDZ4 and UCLA7.3. Model outputs are compared to observations, discussed model by model and with an ensemble (multi-model) approach. As in previous studies the anomalous Mediterranean warm events are associated with specific impacts over the African monsoon region, i.e., a more intense monsoon, enhanced flux convergence and ascendances around the ITCZ, a strengthening of low level moisture advection and a more northward location of ascending motion in West Africa. The results show also new features (1) thermal variability observed in the two Mediterranean basins has unalike impacts, i.e. the western Mediterranean covaries with convection in Gulf of Guinea, while the eastern Mediterranean can be interpreted as Sahelian thermal-forcing; (2) although observations show symmetry between warming and cooling, modelling evidences only support the eastern warming influence; (3) anomalous East warm situations are associated with a more northward migration of the monsoon system accompanied by enhanced southwertely flow and weakened northeasterly climatological wind; (4) the multi-model response shows that anomalous East warm surface temperatures generate an enhancement of the overturning circulation in low and high levels, an increase in TEJ (Tropical Eeasterly Jet) and a decrease in AEJ (African Eeasterly Jet). (orig.)

  3. A Harassing Climate? Sexual Harassment and Campus Racial Climate Research

    Science.gov (United States)

    Lundy-Wagner, Valerie; Winkle-Wagner, Rachelle

    2013-01-01

    In this conceptual paper, the authors discuss how research about sexual harassment and campus racial climates for undergraduate students is relegated to separate silos. Drawing on intersectionality and critical race feminist frameworks, the authors juxtapose these strands of research with attention to ethnicity/race and gender, highlighting how…

  4. FEATURES AND COMPARISONS OF THE QUASI-BIENNIAL VARIATIONS IN THE ASIA-PACIFIC MONSOON SUBSYSTEMS

    Institute of Scientific and Technical Information of China (English)

    ZHENG Bin; LI Chun-hui; LIN Ai-lan; GU De-jun

    2009-01-01

    The National Centers for Environmental Prediction (NCEP) reanalysis data Climate Diagnostics Center Merged Analysis of Precipitation (CMAP) results,and NOAA Extended Reconstructed Sea Surface Temperature (SST),have been utilized in this paper to study the quasi-biennial variations in Asia-Pacific monsoon subsystems and associated SST anomalies (SSTA) and wind anomalies. Four monsoon indices are computed fi,om NCEP/National Center for Atmospheric Research (NCAR) reanalysis to represent the South Asian monsoon (SAM),South China Sea summer monsoon (SCSSM),Western North Pacific monsoon (WNPM) and East Asian monsoon (EAM),respectively. The quasi-biennial periods are very significant in Asia-Pacific monsoons (as discovered by power spectrum analysis),and for SAM and EAM---with moderate effects by EI Ni(n)o-Southern Oscillation (ENSO)---the quasi-biennial periods are the most important factor. For SCSSM and WNPM (once again due to the effects of ENSO),the quasi-biennial periods are of secondary durations. There are obvious interdecadal variations in the quasi-biennial modes of the Asia-Pacific monsoon,so in the negative phase the biennial modes will not be significant or outstanding. The wind anomalies and SSTA associated with the biennial modes are very different in the SAM. WNPM and EAM regions. Since the WNPM and SCSSM are very similar in the biennial modes,they can be combined into one subsystem,called SCS/WNPM.

  5. Effect of precession on the Asian summer monsoon evolution: A systematic review

    Institute of Scientific and Technical Information of China (English)

    LIU XiaoDong; SHI ZhengGuo

    2009-01-01

    Geological climatic records and model simulations on the Asian summer monsoon climate change induced by insolation forcing of the Earth's precession are systematically reviewed in this paper. The presentation of the questions on the mechanism of the Asian monsoon evolution at the precession band, currently existing debates and future research directions are discussed. Since the early 1980s, more and more observed evidence and simulated results, especially the absolute-dated stalagmite re-cords and orbital-scale transient model runs in the last few years, have indicated that the quasi-20ka period in the Quaternary monsoon climate change is caused by precession. However, debates still exist on the dynamic mechanism how precession affects the Asian monsoon. The "zero phase" hypothesis says that the Asian monsoon is merely controlled by summer insolation in the Northern Hemisphere (NH) while the "latent heat" hypothesis emphasizes the dominant effect of latent heat transport from the Southern Hemisphere (SH) besides the role of the northern insolation. The two hypotheses have separately been supported by some evidence. Although we are cognizant of the importance of northern solar radiation and the remote effect of southern insolation, it has still a long way to go before com-prehensively understanding the evolutionary mechanism of the Asian monsoon. In view of the prob-lems existing in present researches of monsoon-dominated climate change at the precession scale, we propose that studies on the environmental significance of geological monsoon proxies, feedback processes in the long-term transient simulations and intercomparisons between observations and modeling results should be strengthened in the future.

  6. Monsoon Country

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Heavy rains have battered areas of south China this year,causing death and destruction For most areas south of the Yangtze River,this year’s monsoon season has come early, with heavy rains triggering floods,damaging crops,threatening reservoirs and causing deaths.

  7. Simulation of Indian summer monsoon intraseasonal oscillations in a superparameterized coupled climate model: need to improve the embedded cloud resolving model

    Science.gov (United States)

    Goswami, Bidyut B.; Mukhopadhyay, P.; Khairoutdinov, Marat; Goswami, B. N.

    2013-09-01

    The characteristic features of Indian summer monsoon (ISM) and monsoon intraseasonal oscillations (MISO) are analyzed in the 25 year simulation by the superparameterized Community Climate System Model (SP-CCSM). The observations indicate the low frequency oscillation with a period of 30-60 day to have the highest power with a dominant northward propagation, while the faster mode of MISO with a period of 10-20 day shows a stationary pattern with no northward propagation. SP-CCSM simulates two dominant quasi-periodic oscillations with periods 15-30 day and 40-70 day indicating a systematic low frequency bias in simulating the observed modes. Further, contrary to the observation, the SP-CCSM 15-30 day mode has a significant northward propagation; while the 40-70 day mode does not show prominent northward propagation. The inability of the SP-CCSM to reproduce the observed modes correctly is shown to be linked with inability of the cloud resolving model (CRM) to reproduce the characteristic heating associated with the barotropic and baroclinic vertical structures of the high-frequency and the low-frequency modes. It appears that the superparameterization in the General Circulation Model (GCM) certainly improves seasonal mean model bias significantly. There is a need to improve the CRM through which the barotropic and baroclinic modes are simulated with proper space and time distribution.

  8. Considerations in Starting Climate Change Research

    Science.gov (United States)

    Long, J. C. S.; Morgan, G.; Hamburg, S.; Winickoff, D. E.

    2014-12-01

    Many have called for climate engineering research because the growing risks of climate change and the geopolitical and national security risks of climate remediation technologies are real. As the topic of climate engineering remains highly controversial, national funding agencies should evaluate even modest outdoor climate engineering research proposals with respect to societal, legal, and risk considerations in making a decision to fund or not to fund. These concerns will be extremely difficult to coordinate internationally if they are not first considered successfully on a national basis. Assessment of a suite of proposed research projects with respect to these considerations indicates we would learn valuable lessons about how to govern research by initiating a few exemplar projects. The first time an issue arrives it can be very helpful if it there are specific cases, not a broad class of projects. A good first case should be defensible and understandable, fit within the general mandate of existing research programs, have negligible physical risk, small physical scale and short duration. By focusing on a specific case, the discussion can be held with limits and help to establish some track record in dealing with a controversial subject and developing a process for assigning appropriate scrutiny and outreach. Even at an early stage, with low risk, small-scale experiments, obtaining broad-based advice will aid in dealing with the controversies. An independent advisory body can provide guidance about a wide spectrum of physical and social risks of funding the experiment compared to societal benefit of gaining understanding. Clearly identifying the research as climate engineering research avoids sending research down a path that might violate public trust and provide an important opportunity to grow governance and public engagement at an early stage. Climate engineering research should be seen in the context of all approaches to dealing with the climate problem

  9. Climate Change Research in View of Bibliometrics.

    Science.gov (United States)

    Haunschild, Robin; Bornmann, Lutz; Marx, Werner

    2016-01-01

    This bibliometric study of a large publication set dealing with research on climate change aims at mapping the relevant literature from a bibliometric perspective and presents a multitude of quantitative data: (1) The growth of the overall publication output as well as (2) of some major subfields, (3) the contributing journals and countries as well as their citation impact, and (4) a title word analysis aiming to illustrate the time evolution and relative importance of specific research topics. The study is based on 222,060 papers (articles and reviews only) published between 1980 and 2014. The total number of papers shows a strong increase with a doubling every 5-6 years. Continental biomass related research is the major subfield, closely followed by climate modeling. Research dealing with adaptation, mitigation, risks, and vulnerability of global warming is comparatively small, but their share of papers increased exponentially since 2005. Research on vulnerability and on adaptation published the largest proportion of very important papers (in terms of citation impact). Climate change research has become an issue also for disciplines beyond the natural sciences. The categories Engineering and Social Sciences show the strongest field-specific relative increase. The Journal of Geophysical Research, the Journal of Climate, the Geophysical Research Letters, and Climatic Change appear at the top positions in terms of the total number of papers published. Research on climate change is quantitatively dominated by the USA, followed by the UK, Germany, and Canada. The citation-based indicators exhibit consistently that the UK has produced the largest proportion of high impact papers compared to the other countries (having published more than 10,000 papers). Also, Switzerland, Denmark and also The Netherlands (with a publication output between around 3,000 and 6,000 papers) perform top-the impact of their contributions is on a high level. The title word analysis shows that

  10. Statistical bias correction method applied on CMIP5 datasets over the Indian region during the summer monsoon season for climate change applications

    Science.gov (United States)

    Prasanna, V.

    2016-11-01

    This study makes use of temperature and precipitation from CMIP5 climate model output for climate change application studies over the Indian region during the summer monsoon season (JJAS). Bias correction of temperature and precipitation from CMIP5 GCM simulation results with respect to observation is discussed in detail. The non-linear statistical bias correction is a suitable bias correction method for climate change data because it is simple and does not add up artificial uncertainties to the impact assessment of climate change scenarios for climate change application studies (agricultural production changes) in the future. The simple statistical bias correction uses observational constraints on the GCM baseline, and the projected results are scaled with respect to the changing magnitude in future scenarios, varying from one model to the other. Two types of bias correction techniques are shown here: (1) a simple bias correction using a percentile-based quantile-mapping algorithm and (2) a simple but improved bias correction method, a cumulative distribution function (CDF; Weibull distribution function)-based quantile-mapping algorithm. This study shows that the percentile-based quantile mapping method gives results similar to the CDF (Weibull)-based quantile mapping method, and both the methods are comparable. The bias correction is applied on temperature and precipitation variables for present climate and future projected data to make use of it in a simple statistical model to understand the future changes in crop production over the Indian region during the summer monsoon season. In total, 12 CMIP5 models are used for Historical (1901-2005), RCP4.5 (2005-2100), and RCP8.5 (2005-2100) scenarios. The climate index from each CMIP5 model and the observed agricultural yield index over the Indian region are used in a regression model to project the changes in the agricultural yield over India from RCP4.5 and RCP8.5 scenarios. The results revealed a better

  11. Gaps in agricultural climate adaptation research

    Science.gov (United States)

    Davidson, Debra

    2016-05-01

    The value of the social sciences to climate change research is well recognized, but notable gaps remain in the literature on adaptation in agriculture. Contributions focus on farmer behaviour, with important research regarding gender, social networks and institutions remaining under-represented.

  12. Modeling sensitivity study of the possible impact of snow and glaciers developing over Tibetan Plateau on Holocene African-Asian summer monsoon climate

    Directory of Open Access Journals (Sweden)

    L. Jin

    2008-12-01

    Full Text Available The impacts of various scenarios of snow and glaciers developing over the Tibetan Plateau on climate change in Afro-Asian monsoon region and other regions during the Holocene (9 kyr BP–0 kyr BP are studied by using the coupled climate model of intermediate complexity, CLIMBER-2. The simulations show that the imposed snow and glaciers over the Tibetan Plateau in the mid-Holocene induce global summer temperature decreases, especially in the northern parts of Europe, Asia, and North America. At the same time, with the imposed snow and glaciers, summer precipitation decreases strongly in North Africa and South Asia as well as northeastern China, while it increases in Southeast Asia and the Mediterranean. For the whole period of Holocene (9 kyr BP–0 kyr BP, the response of vegetation cover to the imposed snow and glaciers cover over the Tibetan Plateau is not synchronous in South Asia and in North Africa, showing an earlier and a more rapid decrease in vegetation cover in North Africa from 9 to 6 kyr BP while it has only minor influence on that in South Asia until 5 kyr BP. Imposed gradually increased snow and glacier cover over the Tibetan Plateau causes temperature increases in South Asia and it decreases in North Africa and Southeast Asia during 6 kyr BP to 0 kyr BP. The precipitation decreases rapidly in North Africa and South Asia while it decreases slowly or unchanged during 6 kyr BP to 0 kyr BP with imposed snow and glacier cover over the Tibetan Plateau. The different scenarios of snow and glacier developing over the Tibetan Plateau would result in differences in variation of temperature, precipitation and vegetation cover in North Africa, South Asia and Southeast Asia. The model results show that the response of climate change in African-Asian monsoon region to snow and glacier cover over the Tibetan Plateau is in the way that the snow and glaciers amplify the effect of vegetation feedback and, hence, further amplify orbital forcing.

  13. The Response of the South Asian Summer Monsoon Circulation to Intensified Irrigation in Global Climate Model Simulations

    Science.gov (United States)

    Shukla, Sonali P.; Puma, Michael J.; Cook, Benjamin I.

    2013-01-01

    Agricultural intensification in South Asia has resulted in the expansion and intensification of surface irrigation over the twentieth century. The resulting changes to the surface energy balance could affect the temperature contrasts between the South Asian land surface and the equatorial Indian Ocean, potentially altering the South Asian Summer Monsoon (SASM) circulation. Prior studies have noted apparent declines in the monsoon intensity over the twentieth century and have focused on how altered surface energy balances impact the SASM rainfall distribution. Here, we use the coupled Goddard Institute for Space Studies ModelE-R general circulation model to investigate the impact of intensifying irrigation on the large-scale SASM circulation over the twentieth century, including how the effect of irrigation compares to the impact of increasing greenhouse gas (GHG) forcing. We force our simulations with time-varying, historical estimates of irrigation, both alone and with twentieth century GHGs and other forcings. In the irrigation only experiment, irrigation rates correlate strongly with lower and upper level temperature contrasts between the Indian sub-continent and the Indian Ocean (Pearson's r = -0.66 and r = -0.46, respectively), important quantities that control the strength of the SASM circulation. When GHG forcing is included, these correlations strengthen: r = -0.72 and r = -0.47 for lower and upper level temperature contrasts, respectively. Under irrigated conditions, the mean SASM intensity in the model decreases only slightly and insignificantly. However, in the simulation with irrigation and GHG forcing, inter-annual variability of the SASM circulation decreases by *40 %, consistent with trends in the reanalysis products. This suggests that the inclusion of irrigation may be necessary to accurately simulate the historical trends and variability of the SASM system over the last 50 years. These findings suggest that intensifying irrigation, in concert with

  14. Interweaving climate research and public understanding

    Science.gov (United States)

    Betts, A. K.

    2016-12-01

    For the past 10 years I have been using research into land-atmosphere-cloud coupling to address Vermont's need to understand climate change, and develop plans for greater resilience in the face of increasing severe weather. The research side has shown that the fraction of days with snow cover determines the cold season climate, because snow acts as a fast climate switch between non-overlapping climates with and without snow cover. Clouds play opposite roles in warm and cold seasons: surface cooling in summer and warming in winter. The later fall freeze-up and earlier spring ice-out on lakes, coupled to the earlier spring phenology, are clear markers both of a warming climate, as well as the large interannual variability. Severe flooding events have come with large-scale quasi-stationary weather patterns. This past decade I have given 230 talks to schools, business and professional groups, as well as legislative committees and state government. I have written 80 environmental columns for two Vermont newspapers, as part of a weekly series I helped start in 2008. Commentaries and interviews on radio and TV enable me to explain directly the issues we face, as the burning of fossil fuels destabilizes the climate system. The public in Vermont is eager to learn and understand these issues since many have roots in the land; while professional groups need all the information and guidance possible to prepare for the future. My task as a scientist is to map out what we know in ways that can readily be grasped in terms of past experience, even though the climate system is already moving outside this range - and at the same time outline general principles and hopeful strategies for dealing with global and local climate change.

  15. Enhanced climate variability in the tropics: a 200 000 yr annual record of monsoon variability from Pangea's equator

    Directory of Open Access Journals (Sweden)

    R. Y. Anderson

    2011-07-01

    Full Text Available A continuous series of 209 000 evaporite varves from the equator of arid western Pangea (age = −255 ma, as a proxy for surface temperature, has a complete suite of Milankovitch cycles and harmonics as expected for a rectified reaction to precession-modulated insolation at the equator. Included are modes of precession (23.4 kyr, 18.2 kyr, semi-precession (11.7 kyr, 9.4 kyr, and harmonics at ~7 kyr and 5.4 kyr. An oscillation of ~100 kyr, with 35 % of total variance, originates as an amplitude modulation of precession cycles. An exceptionally strong 2.3 kyr quasi-bi-millennial oscillation (QBMO appears to have had its own source of forcing, possibly solar, with its amplitude enhanced at Milankovitch frequencies. Seasonal information in varves traces the rectifying process to asymmetrical distribution of Pangea relative to the equator, and its effect on monsoonal circulation and heat flow near the equator during summer solstices in the hemispheres.

  16. Investigating the impact of land-use land-cover change on Indian summer monsoon daily rainfall and temperature during 1951–2005 using a regional climate model

    Directory of Open Access Journals (Sweden)

    S. Halder

    2015-07-01

    Full Text Available Daily moderate rainfall events, that constitute a major portion of seasonal summer monsoon rainfall over central India, have decreased significantly during the period 1951 till 2005. Mean and extreme near surface daily temperature during the monsoon season have also increased by a maximum of 1–1.5 °C. Using simulations made with a high-resolution regional climate model (RegCM4 with prescribed vegetation cover of 1950 and 2005, it is demonstrated that part of the above observed changes in moderate rainfall events and temperature have been caused by land-use land-cover change (LULCC which is mostly anthropogenic. Model simulations show that the increase in seasonal mean and extreme temperature over central India coincides with the region of decreased (increased forest (crop cover. The results also show that land-use land-cover alone causes warming in the extremes of daily mean and maximum temperatures by maximum of 1–1.2 °C, that is comparable with the observed increasing trend in the extremes. Decrease (increase in forest (crop cover reduces the evapotranspiration over land and large-scale convective instability, apart from decreasing the moisture convergence. These factors act together not only in reducing the moderate rainfall events over central India but also the amount of rainfall in that category, significantly. This is the most interesting result of this study. Additionally, the model simulations are repeated by removing the warming trend in sea surface temperatures. As a result, there is enhanced warming at the surface and decrease in moderate rainfall events over central India. Results from the additional experiments corroborate our initial findings and confirm the contribution of land-use land-cover change on increase in daily mean and extreme temperature and decrease in moderate rainfall events. This study not only demonstrates the important implications of LULCC over India, but also shows the necessity for inclusion of projected

  17. Integrated Assessments of the Impact of Climate Change on Agriculture: An Overview of AgMIP Regional Research in South Asia

    Science.gov (United States)

    McDermid, Sonali P.; Dileepkumar, Guntuku; Murthy, K. M. Dakshina; Nedumaran, S.; Singh, Piara; Srinivasa, Chukka; Gangwar, B.; Subash, N.; Ahmad, Ashfaq; Zubair, Lareef; Nissanka, S. P.

    2015-01-01

    South Asia encompasses a wide and highly varied geographic region, and includes climate zones ranging from the mountainous Himalayan territory to the tropical lowland and coastal zones along alluvial floodplains. The region's climate is dominated by a monsoonal circulation that heralds the arrival of seasonal rainfall, upon which much of the regional agriculture relies. The spatial and temporal distribution of this rainfall is, however, not uniform over the region. Northern South Asia, central India, and the west coast receive much of their rainfall during the southwest monsoon season, between June and September. These rains partly result from the moisture transport accompanying the monsoonal winds, which move in the southwesterly direction from the equatorial Indian Ocean. Regions further south, such as south/southeast India and Sri Lanka, may receive rains from both the southwest monsoon, and also during the northeast monsoon season between October and December (with northeasterly monsoon wind flow and moisture flux), which results in a bi- or multi-modal rainfall distribution. In addition, rainfall across South Asia displays a large amount of intraseasonal and interannual variability. Interannual variability is influenced by many drivers, both natural (e.g., El Ni-Southern Oscillation; ENSO) and man-made (e.g., rising temperatures due to increasing greenhouse gas concentrations), and it is challenging to obtaining accurate time-series of annual rainfall, even amongst various observed data products, which display inconsistencies amongst themselves. These climatic and rainfall variations can further complicate South Asia's agricultural and water management. Agriculture employs at least 65 of the workforce in most South Asian countries, and nearly 80 of South Asia's poor inhabit rural areas. Understanding the response of current agricultural production to climate variability and future climate change is of utmost importance in securing food and livelihoods for

  18. Retrospect and prospect: advances and future strategies in climate research

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A brief review of the progress in climate research and a prospect on its further development in the 21st century is presented. Some key findings including the concept of climate system, the discovery of climatic multi-equilibrium and abrupt climate changes, and the recognition of human activities as an important force of climate change made breakthroughs in climatology possible during last few decades. The adaptation to climatic and global change emerged as a new aspect of climatic research during the 1990s. Climate research will break through in the observation of the global system, in the analysis of mass data, in the deepening of research on the mechanism of climatic change, and in the improvement of models. In the applied fields of climate research, there will be substantial progress in the research on adaptation to global change and sustainable development, on orderly human activities, and climate modification.

  19. Getting African climate change research recognised

    Energy Technology Data Exchange (ETDEWEB)

    Denton, Fatima; Anderson, Simon; Ayers, Jessica

    2011-11-15

    Across Africa, programmes such as the Climate Change Adaptation in Africa initiative are investigating what it means for countries and communities to effectively adapt to climate change, and how this can be achieved in practice. But research results are not always recognised by policymakers or the global research community — in part because they are not visible within the traditional hallmark of scientific scholarship and credibility, peer-reviewed literature. Greater efforts are required to encourage African scientists to engage in the peer-review process and give their research the credibility it needs to convince decision makers that robust scientific findings support the solutions offered. At the same time, decision makers themselves must find ways of assessing and making use of robust research outside the peer-review arena.

  20. The research in climate system modeling, simulating and forecasting

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ The major point of the World Climate Research Program (WCRP) is to predict the real-time climate change in seasons and years. Climate disasters in China occurred frequently, and resulted in a 200 billion RMB lost annually.

  1. GMMIP (v1.0) contribution to CMIP6: Global Monsoons Model Inter-comparison Project

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Tianjun; Turner, Andrew G.; Kinter, James L.; Wang, Bin; Qian, Yun; Chen, Xiaolong; Wu, Bo; Wang, Bin; Liu, Bo; Zou, Liwei; He, Bian

    2016-10-10

    The Global Monsoons Model Inter-comparison Project (GMMIP) has been endorsed by the panel of Coupled Model Inter-comparison Project (CMIP) as one of the participating model inter-comparison projects (MIPs) in the sixth phase of CMIP (CMIP6). The focus of GMMIP is on monsoon climatology, variability, prediction and projection, which is relevant to four of the “Grand Challenges” proposed by the World Climate Research Programme. At present, 21 international modeling groups are committed to joining GMMIP. This overview paper introduces the motivation behind GMMIP and the scientific questions it intends to answer. Three tiers of experiments, of decreasing priority, are designed to examine (a) model skill in simulating the climatology and interannual-to-multidecadal variability of global monsoons forced by the sea surface temperature during historical climate period; (b) the roles of the Interdecadal Pacific Oscillation and Atlantic Multidecadal Oscillation in driving variations of the global and regional monsoons; and (c) the effects of large orographic terrain on the establishment of the monsoons. The outputs of the CMIP6 Diagnostic, Evaluation and Characterization of Klima experiments (DECK), “historical” simulation and endorsed MIPs will also be used in the diagnostic analysis of GMMIP to give a comprehensive understanding of the roles played by different external forcings, potential improvements in the simulation of monsoon rainfall at high resolution and reproducibility at decadal timescales. The implementation of GMMIP will improve our understanding of the fundamental physics of changes in the global and regional monsoons over the past 140 years and ultimately benefit monsoons prediction and projection in the current century.

  2. GMMIP (v1.0) contribution to CMIP6: Global Monsoons Model Inter-comparison Project

    Science.gov (United States)

    Zhou, Tianjun; Turner, Andrew G.; Kinter, James L.; Wang, Bin; Qian, Yun; Chen, Xiaolong; Wu, Bo; Wang, Bin; Liu, Bo; Zou, Liwei; He, Bian

    2016-10-01

    The Global Monsoons Model Inter-comparison Project (GMMIP) has been endorsed by the panel of Coupled Model Inter-comparison Project (CMIP) as one of the participating model inter-comparison projects (MIPs) in the sixth phase of CMIP (CMIP6). The focus of GMMIP is on monsoon climatology, variability, prediction and projection, which is relevant to four of the "Grand Challenges" proposed by the World Climate Research Programme. At present, 21 international modeling groups are committed to joining GMMIP. This overview paper introduces the motivation behind GMMIP and the scientific questions it intends to answer. Three tiers of experiments, of decreasing priority, are designed to examine (a) model skill in simulating the climatology and interannual-to-multidecadal variability of global monsoons forced by the sea surface temperature during historical climate period; (b) the roles of the Interdecadal Pacific Oscillation and Atlantic Multidecadal Oscillation in driving variations of the global and regional monsoons; and (c) the effects of large orographic terrain on the establishment of the monsoons. The outputs of the CMIP6 Diagnostic, Evaluation and Characterization of Klima experiments (DECK), "historical" simulation and endorsed MIPs will also be used in the diagnostic analysis of GMMIP to give a comprehensive understanding of the roles played by different external forcings, potential improvements in the simulation of monsoon rainfall at high resolution and reproducibility at decadal timescales. The implementation of GMMIP will improve our understanding of the fundamental physics of changes in the global and regional monsoons over the past 140 years and ultimately benefit monsoons prediction and projection in the current century.

  3. Latitudinal gradients in tree ring stable carbon and oxygen isotopes reveal differential climate influences of the North American Monsoon System

    Science.gov (United States)

    Szejner, Paul; Wright, William E.; Babst, Flurin; Belmecheri, Soumaya; Trouet, Valerie; Leavitt, Steven W.; Ehleringer, James R.; Monson, Russell K.

    2016-07-01

    The arrival of the North American Monsoon System (NAMS) terminates a presummer hyperarid period in the southwestern United States (U.S.), providing summer moisture that is favorable for forest growth. Montane forests in this region rely on winter snowpack to drive much of their growth; the extent to which they use NAMS moisture is uncertain. We addressed this by studying stable carbon and oxygen isotopes in earlywood and latewood from 11 sites along a latitudinal gradient extending from Arizona and New Mexico to Utah. This study provides the first regional perspective on the relative roles of winter versus summer precipitation as an ecophysiological resource. Here we present evidence that Ponderosa pine uses NAMS moisture differentially across this gradient. 13C/12C ratios suggest that photosynthetic water use efficiency during latewood formation is more sensitive to summer precipitation at the northern than at the southern sites. This is likely due to the fact that NAMS moisture provides sufficiently favorable conditions for tree photosynthesis and growth during most years in the southern sites, whereas the northern sites experience larger summer moisture variability, which in some years is limiting growth. Cellulose δ18O and δ13C values revealed that photoassimilates in the southern sites were produced under higher vapor pressure deficit conditions during spring compared to summer, demonstrating a previously underappreciated effect of seasonal differences in atmospheric humidity on tree ring isotope ratios. Our findings suggest that future changes in NAMS will potentially alter productivity and photosynthetic water use dynamics differentially along latitudinal gradients in southwestern U.S. montane forests.

  4. High-resolution peat records for Holocene monsoon history in the eastern Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    YU; Xuefeng; ZHOU; Weijian; Lars; G.Franzen; XIAN; Feng; CHENG; Peng; A.J.; Tim; Jull

    2006-01-01

    The variations of summer and winter monsoons during the Holocene in the eastern Tibetan Plateau are shown to follow two basic models based on the reliable dating and high-resolution monsoon proxies determinations, one being a synchronous model in that both summer and winter monsoons are strengthening or decreasing, and the other to form a complementary pattern. These two different patterns evenly interact with each other on different time scales and together compose a complicated monsoon climatic model in this region. The climatic condition integrated by winter and summer monsoons is synchronous to the global pattern, which also shows the instability of the Holocene climate on centennial-millennial timescale. The abrupt monsoon event in about 6.2 ka cal.BP is much more severe than that in ca. 8.0 ka cal. BP, which indicates the regional character of the Asian monsoon and that the Asian monsoon climate is indeed a window on the global climate system.

  5. Uncertainty and global climate change research

    Energy Technology Data Exchange (ETDEWEB)

    Tonn, B.E. [Oak Ridge National Lab., TN (United States); Weiher, R. [National Oceanic and Atmospheric Administration, Boulder, CO (United States)

    1994-06-01

    The Workshop on Uncertainty and Global Climate Change Research March 22--23, 1994, in Knoxville, Tennessee. This report summarizes the results and recommendations of the workshop. The purpose of the workshop was to examine in-depth the concept of uncertainty. From an analytical point of view, uncertainty is a central feature of global climate science, economics and decision making. The magnitude and complexity of uncertainty surrounding global climate change has made it quite difficult to answer even the most simple and important of questions-whether potentially costly action is required now to ameliorate adverse consequences of global climate change or whether delay is warranted to gain better information to reduce uncertainties. A major conclusion of the workshop is that multidisciplinary integrated assessments using decision analytic techniques as a foundation is key to addressing global change policy concerns. First, uncertainty must be dealt with explicitly and rigorously since it is and will continue to be a key feature of analysis and recommendations on policy questions for years to come. Second, key policy questions and variables need to be explicitly identified, prioritized, and their uncertainty characterized to guide the entire scientific, modeling, and policy analysis process. Multidisciplinary integrated assessment techniques and value of information methodologies are best suited for this task. In terms of timeliness and relevance of developing and applying decision analytic techniques, the global change research and policy communities are moving rapidly toward integrated approaches to research design and policy analysis.

  6. Soil-vegetation-climate interactions in arid landscapes: Effects of the North American monsoon on grass recruitment

    Science.gov (United States)

    We used a daily time step, multi-layer simulation model of soil water dynamics to integrate effects of soils, vegetation, and climate on the recruitment of Bouteloua eriopoda (black grama), the historically dominant grass in the Chihuahuan Desert. We simulated landscapes at the Jornada ARS-LTER site...

  7. An Assessment of the South Asian Summer Monsoon Variability for Present and Future Climatologies Using a High Resolution Regional Climate Model (RegCM4.3 under the AR5 Scenarios

    Directory of Open Access Journals (Sweden)

    Mujtaba Hassan

    2015-11-01

    Full Text Available We assessed the present and future climatologies of mean summer monsoon over South Asia using a high resolution regional climate model (RegCM4 with a 25 km horizontal resolution. In order to evaluate the performance of the RegCM4 for the reference period (1976–2005 and for the far future (2070–2099, climate change projections under two greenhouse gas representative concentration pathways (RCP4.5 and RCP8.5 were made, the lateral boundary conditions being provided by the geophysical fluid dynamic laboratory global model (GFDL-ESM2M. The regional climate model (RCM improves the simulation of seasonal mean temperature and precipitation patterns compared to driving global climate model (GCM during present-day climate conditions. The regional characteristic features of South Asian summer monsoon (SASM, like the low level jet stream and westerly flow over the northern the Arabian Sea, are well captured by the RegCM4. In spite of some discrepancies, the RegCM4 could simulate the Tibetan anticyclone and the direction of the tropical easterly jet reasonably well at 200 hPa. The projected temperature changes in 2070–2099 relative to 1976–2005 for GFDL-ESM2M show increased warming compared to RegCM4. The projected patterns at the end of 21st century shows an increase in precipitation over the Indian Peninsula and the Western Ghats. The possibilities of excessive precipitation include increased southwesterly flow in the wet period and the effect of model bias on climate change. However, the spatial patterns of precipitation are decreased in intensity and magnitude as the monsoon approaches the foothills of the Himalayas. The RegCM4-projected dry conditions over northeastern India are possibly related to the anomalous anticyclonic circulations in both scenarios.

  8. Climate change under a scenario near 1.5 °C of global warming: monsoon intensification, ocean warming and steric sea level rise

    Directory of Open Access Journals (Sweden)

    M. Meinshausen

    2010-10-01

    Full Text Available We present climatic consequences of the Representative Concentration Pathways (RCPs using the coupled climate model CLIMBER-3α, which contains a statistical-dynamical atmosphere and a three-dimensional ocean model. We compare those with emulations of 19 state-of-the-art atmosphere-ocean general circulation models (AOGCM using MAGICC6. The RCPs are designed as standard scenarios for the forthcoming IPCC Fifth Assessment Report to span the full range of possible future greenhouse gas (GHG concentrations pathways. The lowest of the RCP scenarios, RCP3-PD, is projected in CLIMBER-3α to imply a maximal warming by the middle of the 21st century slightly above 1.5 °C and a slow decline of temperatures thereafter, approaching today's level by 2500. We identify two mechanisms that slow down global cooling after GHG concentrations peak: The known inertia induced by mixing-related oceanic heat uptake; and a change in oceanic convection that enhances ocean heat loss in high latitudes, reducing the surface cooling rate by almost 50%. Steric sea level rise under the RCP3-PD scenario continues for 200 years after the peak in surface air temperatures, stabilizing around 2250 at 30 cm. This contrasts with around 2 m of steric sea level rise by 2500 under the highest scenario, RCP8.5. Maximum oceanic warming at intermediate depth (300–800 m is found to exceed that of the sea surface by the second half of the 21st century under RCP3-PD. This intermediate-depth warming persists for centuries even after surface temperatures have returned to present-day values, with potential consequences for marine ecosystems, oceanic methane hydrates, and ice-shelf stability. Due to an enhanced land-ocean temperature contrast, all scenarios yield an intensification of monsoon rainfall under global warming.

  9. Climate change under a scenario near 1.5 °C of global warming: monsoon intensification, ocean warming and steric sea level rise

    Directory of Open Access Journals (Sweden)

    J. Schewe

    2011-03-01

    Full Text Available We present climatic consequences of the Representative Concentration Pathways (RCPs using the coupled climate model CLIMBER-3α, which contains a statistical-dynamical atmosphere and a three-dimensional ocean model. We compare those with emulations of 19 state-of-the-art atmosphere-ocean general circulation models (AOGCM using MAGICC6. The RCPs are designed as standard scenarios for the forthcoming IPCC Fifth Assessment Report to span the full range of future greenhouse gas (GHG concentrations pathways currently discussed. The lowest of the RCP scenarios, RCP3-PD, is projected in CLIMBER-3α to imply a maximal warming by the middle of the 21st century slightly above 1.5 °C and a slow decline of temperatures thereafter, approaching today's level by 2500. We identify two mechanisms that slow down global cooling after GHG concentrations peak: The known inertia induced by mixing-related oceanic heat uptake; and a change in oceanic convection that enhances ocean heat loss in high latitudes, reducing the surface cooling rate by almost 50%. Steric sea level rise under the RCP3-PD scenario continues for 200 years after the peak in surface air temperatures, stabilizing around 2250 at 30 cm. This contrasts with around 1.3 m of steric sea level rise by 2250, and 2 m by 2500, under the highest scenario, RCP8.5. Maximum oceanic warming at intermediate depth (300–800 m is found to exceed that of the sea surface by the second half of the 21st century under RCP3-PD. This intermediate-depth warming persists for centuries even after surface temperatures have returned to present-day values, with potential consequences for marine ecosystems, oceanic methane hydrates, and ice-shelf stability. Due to an enhanced land-ocean temperature contrast, all scenarios yield an intensification of monsoon rainfall under global warming.

  10. Climate engineering research : A precautionary response to climate change?

    NARCIS (Netherlands)

    Reynolds, J.L.; Fleurke, F.M.

    2013-01-01

    In the face of dire forecasts for anthropogenic climate change, climate engineering is increasingly discussed as a possible additional set of responses to reduce climate change’s threat. These proposals have been controversial, in part because they – like climate change itself – pose uncertain risks

  11. Climate engineering research : A precautionary response to climate change?

    NARCIS (Netherlands)

    Reynolds, J.L.; Fleurke, F.M.

    2013-01-01

    In the face of dire forecasts for anthropogenic climate change, climate engineering is increasingly discussed as a possible additional set of responses to reduce climate change’s threat. These proposals have been controversial, in part because they – like climate change itself – pose uncertain risks

  12. Role of dynamics in the advection of aerosols over the Arabian Sea along the west coast of peninsular India during pre-monsoon season: A case study based on satellite data and regional climate model

    Indian Academy of Sciences (India)

    Marina Aloysius; S Sijikumar; S S Prijith; Mannil Mohan; K Parameswaran

    2011-04-01

    The circulation dynamics of an event marked by the formation of an aerosol cluster off the coast of Maharashtra on April 22, 2006, its southward migration along the Indian west coast with a mean speed of ∼200 km/day and its final dissipation after reaching the end of the peninsula by April 28, 2006 as revealed by MODIS (Moderate Resolution Imaging Spectroradiometer) against the pre-monsoon conditions of April 2006 are examined in this study. The maximum aerosol concentration in the cluster was found getting confined to lower and lower altitudes during its southward movement. The NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis wind field indicates that the atmospheric circulation, especially the horizontal wind convergence is the major factor that guides the formation and the dynamics of the cluster. Fine mode fraction from MODIS suggests that the cluster mainly consists of coarse dust particles. The regional climate model, RegCM3 with an efficient dust generation module simulates the formation and movement of the cluster appreciably well. The simulations which also exhibit the altitudinally descending nature of the cluster during its southward movement confirm the mechanism which governs the cluster dynamics suggested based on MODIS and NCEP/NCAR reanalysis data.

  13. ARM Climate Research Facility Annual Report 2004

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, J.

    2004-12-31

    Like a rock that slowly wears away beneath the pressure of a waterfall, planet earth?s climate is almost imperceptibly changing. Glaciers are getting smaller, droughts are lasting longer, and extreme weather events like fires, floods, and tornadoes are occurring with greater frequency. Why? Part of the answer is clouds and the amount of solar radiation they reflect or absorb. These two factors clouds and radiative transfer represent the greatest source of error and uncertainty in the current generation of general circulation models used for climate research and simulation. The U.S. Global Change Research Act of 1990 established an interagency program within the Executive Office of the President to coordinate U.S. agency-sponsored scientific research designed to monitor, understand, and predict changes in the global environment. To address the need for new research on clouds and radiation, the U.S. Department of Energy (DOE) established the Atmospheric Radiation Measurement (ARM) Program. As part of the DOE?s overall Climate Change Science Program, a primary objective of the ARM Program is improved scientific understanding of the fundamental physics related to interactions between clouds and radiative feedback processes in the atmosphere.

  14. Global monsoon in a geological perspective

    Institute of Scientific and Technical Information of China (English)

    WANG PinXian

    2009-01-01

    Monsoon is now considered as a global system rather than regional phenomena only. For over 300 years, monsoon has been viewed as a gigantic land-sea breeze, but now satellite and conventional observations support an alternative hypothesis which considers monsoon as a manifestation of sea-sonal migration of the intertropical convergence zone (ITCZ) and, hence, a climate system of the global scale. As a low-latitude climate system, monsoon exists over all continents but Antarctica, and through all the geological history at least since the Phenorozoic. The time is ripe for systematical studies of monsoon variations in space and time.As evidenced by the geological records, the global monsoon is controlled by the Wilson cycle on the tectonic time scale (106-108a). A "Mega-continent" produces "Mega-monsoon", and its breakdown leads to weakening of the monsoon Intensity. On the time scales of 104-105 a, the global monsoon displays the precessional cycles of~20 ka and eccentricity cycles of 100- and 400-ka, i.e. the orbital cycles. On the time scales of 103 a and below, the global monsoon intensity is modulated by solar cy-cles and other factors. The cyclicity of global monsoon represents one of the fundamental factors re-sponsible for variations in the Earth surface system as well as for the environmental changes of the human society. The 400-ka long eccentricity cycles of the global monsoon is likened to "heartbeat" of the Earth system, and the precession cycle of the global monsoon was responsible for the collapse of several Asian and African ancient cultures at~4000 years ago, whereas the Solar cycles led to the de-mise of the Maya civilization about a thousand years ago. Therefore, paleoclimatology should be fo-cused not only on the high-latitude processes centered at ice cap variations, but also on the low-latitude processes such as monsoons, as the latter are much more common in the geological history compared to the glaciations.

  15. Similar speleothem δ18O signals indicating diverging climate variations in inland central Asia and monsoonal south Asia during the Holocene

    Science.gov (United States)

    Jin, Liya; Zhang, Xiaojian

    2017-04-01

    High-resolution and precisely dated speleothem oxygen isotope (δ18O) records from Asia have provided key evidence for past monsoonal changes. It is found that δ18O records of stalagmites from Kesang Cave (42°52'N, 81°45'E, Xinjiang, China) in inland central Asia were very similar to those from Qunf Cave (17°10'N, 54°18'E, southern Oman) in South Asia, shifting from light to heavy throughout the Holocene, which was regarded as a signal that strong Asian summer monsoon (ASM) may have intruded into the Kesang Cave site and/or adjacent areas in inland central Asia to produce heavy rainfall during the high insolation times (e.g. the early Holocene). However, this is in contrast to conclusions based on other Holocene proxy records and modeling simulations, showing a persistent wetting trend in arid central Asia during the Holocene with a dryer condition in the early Holocene and the wettest condition in the late Holocene. With an analysis of model-proxy data comparison, we revealed a possible physical mechanism responsible for the Holocene evolution of moisture/precipitation in Asian summer monsoon (ASM)-dominated regions and that in the inland central Asia. It is revealed that a recurrent circumglobal teleconnection (CGT) pattern in the summertime mid-latitude circulation of the Northern Hemisphere was closely related to the ASM and the climate of inland central Asia, acting as a bridge linking the ASM to insolation, high-latitude forcing (North Atlantic sea surface temperature (SST)), and low-latitude forcing (tropical Ocean SST). Also, the CGT influence speleothem δ18O values in South Asia via its effect on the amount of precipitation. In addition, the moisture source from the Indian Ocean is associated with relatively high δ18O values compared with that from the North Atlantic Ocean, leading to increased precipitation δ18O values. Hence, the CGT has probably been the key factor responsible for the in-phase relationship in speleothem δ18O values (Kesang Cave

  16. A Study of the Teleconnections in the Asian-Pacific Monsoon Region

    Institute of Scientific and Technical Information of China (English)

    DING Yihui; LIU Yunyun

    2008-01-01

    The interactions among the Asian-Pacific monsoon subsystems have significant impacts on the climatic regimes in the monsoon region and even the whole world. Based on the domestic and foreign related research, an analysis is made of four different teleconnection modes found in the Asian-Pacific monsoon region, which reveal clearly the interactions among the Indian summer monsoon (ISM), the East Asian summer monsoon (EASM), and the western North Pacific summer monsoon (WNPSM). The results show that: (1) In the period of the Asian monsoon onset, the date of ISM onset is two weeks earlier than the beginning of the Meiyu over the Yangtze River Basin, and a teleconnection mode is set up from the southwestern India via the Bay of Bengal (BOB) to the Yangtze River Basin and southern Japan, I.e., the "southern" teleconnection of the Asian summer monsoon. (2) In the Asian monsoon culmination period, the precipitation of the Yangtze River Basin is influenced significantly by the WNPSM through their teleconnection relationship, and is negatively related to the WNPSM rainfall, that is, when the WNPSM is weaker than normal, the precipitation of the Yangtze River Basin is too.re than normal. (3) In contrast to the rainfall over the Yangtze River Basin, the precipitation of northern China (from the 4th pentad of July to the 3rd pentad of August) is positively related to the WNPSM. When the WNPSM is stronger than normal, the position of the western Pacific subtropical high (WPSH) becomes farther northeast than normal, the anomalous northeastward water vapor transport along the southwestern flank of WPSH is converged over northern China, providing adequate moisture for more rainfalls than normal there. (4) The summer rainfall in northern China has also a positive correlation with the ISM. During the peak period of ISM, a teleconnection pattern is formed from Northwest India via the Tibetan Plateau to northern China, I.e., the "northern" teleconnection of the Asian summer monsoon

  17. Searching for a fingerprint of global warming in the Asian summer monsoon

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, D.B.; Douville, H.; Kumar, K.R. [University of Reading, Reading (United Kingdom). Dept. of Meteorology

    2001-07-01

    This study investigates possible trends in several large-scale indices that describe the Asian summer monsoon. Results from recent atmospheric general circulating experiments are used to provide clues as to how the monsoon might be changing due to the effects of global warming. Interestingly, this study has found that the large-scale wind shear monsoon indices have been decreasing at a rate of 0.1-0.3% per year (based on NCEP/NCAR (National Centre for Atmospheric Research) analyses 1958-98) in quantitative agreement with recent results from doubled CO{sub 2} simulations made using several state-of-the-art climate models. Nevertheless, despite the weakening of the monsoon circulation, all-India rainfall shows no clear trend in either the model results or in the observation re-analyses from 1958-98. Multiple regression is used to separte out the dynamical contribution from the observed all-India rainfall index, and a clear increasing trend then emerges in the non-dynamical residual. A simple dimensionless multivariate monsoon index is proposed that could be of use in monitoring global warming changes in the monsoon. 31 refs., 2 figs., 3 tabs.

  18. Multiproxy reconstruction for Kuroshio responses to Northern Hemispheric oceanic climate and Asian Monsoon since marine isotope stage 5.1 (∼88 ka)

    Science.gov (United States)

    Shi, X.; Wu, Y.; Zou, J.; Liu, Y.; Ge, S.; Zhao, M.; Liu, J.; Zhu, A.; Meng, X.; Yao, Z.; Han, Y.

    2014-04-01

    The Kuroshio, a western boundary current in the Western Pacific, plays a key role in regulating ocean and climate in the East Asia. The evolution of the Kuroshio and its branches has been the focus of paleoceanographic studies. In this study, we applied a multiproxy (grain size, planktonic foraminiferal species, δ18O, alkenone sea surface temperature (SST) and salinity) reconstruction from sediment core CSH1, which is located at the main axis of the Tsushima Warm Current, a branch of the Kuroshio, in the northern Okinawa Trough (OT). This study, for the first time, extended the paleoceanographic record of the Kuroshio to Marine Isotope Stage (MIS) 5.1 (∼88 ka) from the far northern site in the OT. The core CSH1 contains three volcanic layers, K-Ah, AT, and Aso-4, which are ideal chronostratigraphic markers for precise age controls of the core. Planktonic foraminiferal species identified from this core contain warm water species related to the Kuroshio and cold species related to subarctic water mass. The relative abundances of the warm water species are high during MIS 1 and MIS 5.1, while cold species are high during MIS 2. An organic biomarker proxy, alkenone SST measured from CSH1 ranges between 21 and 25 °C with higher values during interglacials (MIS 1, 3.3, 5.1) and interstadials, and lower values during glacials and Heinrich (H)/stadial events. Sea surface salinity (SSS) and the depth of thermocline (DOT) reconstructed based on foraminifera isotopes and faunas indicate dominant Kuroshio responses to Northern Hemispheric climate and Asian Monsoon (AM) since ∼88 ka. The CSH1 SSS appears to be mainly controlled by the local river runoff and open ocean water, while the DOT change seems to be closely related to the strength of Kuroshio and the latitudinal shift of subarctic frontal zone. Our records suggest that during MIS 1 and MIS 5.1 while global sea level was high, the Kuroshio was dominant; while during MIS 2, MIS 3, and MIS 4 with low sea level

  19. Low- and Mid-High Latitude Components of the East Asian Winter Monsoon and Their Reflecting Variations in Winter Climate over Eastern China

    Institute of Scientific and Technical Information of China (English)

    LIU Ge; JI Li-Ren; SUN Shu-Qing; XIN Yu-Fei

    2012-01-01

    The present study defines a low-latitude component (regionally averaged winter 1000-hPa V-winds over 10 25°N, 105 135°E) and a mid-high-latitude component (regionally averaged winter 1000-hPa V-winds over 30 50°N, 110 125°E) of the East Asian winter monsoon (EAWM), which are denoted as EAWM-L and EAWM-M, respectively. The study examines the variation characteristics, reflecting variations in winter climate over eastern China, and associated atmospheric circulations corresponding to the two components. The main results are as follows: 1) the EAWM-L and EAWM-M have consistent variation in some years but opposite variations in other years; 2) the EAWM-M index mainly reflects the extensive temperature variability over eastern China, while the EAWM-L index better reflects the variation in winter precipitation over most parts of eastern China; and 3) corresponding to the variation in the EAWM-M index, anomalous winds over the mid-high latitudes of East Asia modulate the southward invasion of cold air from the high latitudes and accordingly affect temperatures over eastern China. In combination with the variation in the EAWM-L index, anomalous low-latitudinal winds regulate the water vapor transport from tropical oceans to eastern China, resulting in anomalous winter precipitation. These pronounced differences between the EAWM-L and the EAWM-M suggest that it is necessary to explore the monsoons' individual features and effects in the EAWM study.

  20. Monsoonal response to mid-holocene orbital forcing in a high resolution GCM

    Directory of Open Access Journals (Sweden)

    J. H. C. Bosmans

    2012-04-01

    Full Text Available In this study, we use a sophisticated high-resolution atmosphere-ocean coupled climate model, EC-Earth, to investigate the effect of Mid-Holocene orbital forcing on summer monsoons on both hemispheres. During the Mid-Holocene (6 ka, there was more summer insolation on the Northern Hemisphere than today, which intensified the meridional temperature and pressure gradients. Over North Africa, monsoonal precipitation is intensified through increased landward monsoon winds and moisture advection as well as decreased moisture convergence over the oceans and more convergence over land compared to the pre-industrial simulation. Precipitation also extends further north as the ITCZ shifts northward in response to the stronger poleward gradient of insolation. This increase and poleward extent is stronger than in most previous ocean-atmosphere GCM simulations. In north-westernmost Africa, precipitation extends up to 35° N. Over tropical Africa, internal feedbacks completely overcome the direct warming effect of increased insolation. We also find a weakened African Easterly Jet. Over Asia, monsoonal precipitation during the Mid-Holocene is increased as well, but the response is different than over North-Africa. There is more convection over land at the expense of convection over the ocean, but precipitation does not extend further northward, monsoon winds over the ocean are weaker and the surrounding ocean does not provide more moisture. On the Southern Hemisphere, summer insolation and the poleward insolation gradient were weaker during the Mid-Holocene, resulting in a reduced South American monsoon through decreased monsoon winds and less convection, as well as an equatorward shift in the ITCZ. This study corroborates the findings of paleodata research as well as previous model studies, while giving a more detailed account of Mid-Holocene monsoons.

  1. Asian Monsoon Failure and Megadrought During the Last Millennium

    Science.gov (United States)

    Cook, Edward R.; Anchukaitis, Kevin J.; Buckley, Brendan M.; D'Arrigo, Rosanne D.; Jacoby, Gordon C.; Wright, William E.

    2010-04-01

    The Asian monsoon system affects more than half of humanity worldwide, yet the dynamical processes that govern its complex spatiotemporal variability are not sufficiently understood to model and predict its behavior, due in part to inadequate long-term climate observations. Here we present the Monsoon Asia Drought Atlas (MADA), a seasonally resolved gridded spatial reconstruction of Asian monsoon drought and pluvials over the past millennium, derived from a network of tree-ring chronologies. MADA provides the spatiotemporal details of known historic monsoon failures and reveals the occurrence, severity, and fingerprint of previously unknown monsoon megadroughts and their close linkages to large-scale patterns of tropical Indo-Pacific sea surface temperatures. MADA thus provides a long-term context for recent monsoon variability that is critically needed for climate modeling, prediction, and attribution.

  2. Multiproxy reconstruction for Kuroshio responses to northern hemispheric oceanic climate and the Asian Monsoon since Marine Isotope Stage 5.1 (∼88 ka)

    Science.gov (United States)

    Shi, X.; Wu, Y.; Zou, J.; Liu, Y.; Ge, S.; Zhao, M.; Liu, J.; Zhu, A.; Meng, X.; Yao, Z.; Han, Y.

    2014-09-01

    The Kuroshio, a western boundary current in the northwestern Pacific, plays a key role in regulating ocean and climate in East Asia. The evolution of the Kuroshio and its branches has been the focus of paleoceanographic studies. In this study, we applied a multiproxy (grain size, planktonic foraminiferal species, δ18O, alkenone sea surface temperature (SST) and salinity) reconstruction from sediment core CSH1, which is located at the main axis of the Tsushima Warm Current, a branch of the Kuroshio, in the northern Okinawa Trough (OT). This study, extended the paleoceanographic record of the Kuroshio to Marine Isotope Stage (MIS) 5.1 (∼88 ka) from the far northern site in the OT. Planktonic foraminiferal species identified from this core contain warm-water species related to the Kuroshio and cold-water species related to subarctic water mass. The relative abundances of the warm-water species are high during MIS 1 and MIS 5.1, while cold-water species are high during MIS 2. An organic biomarker proxy, alkenone SST measured from core CSH1 ranges between 21 and 25 °C, with higher values during interglacials (MIS 1, 3.3, 5.1) and interstadials and lower values during glacials and Heinrich (H)/stadial events. Sea surface salinity (SSS) and the depth of the thermocline (DOT), reconstructed based on foraminifera isotopes and faunas, indicate dominant Kuroshio responses to an abrupt climate change event recorded in Greenland ice cores and in stalagmites in East China since ∼88 ka. The CSH1 SSS appears to be mainly controlled by the local river runoff and the Kuroshio, while the DOT change seems to be closely related to the strength of the Kuroshio and the latitudinal shift of the subarctic frontal zone. Our records suggest that, during MIS 1 and MIS 5.1, while global sea level was high, the Kuroshio was dominant; while during MIS 2, MIS 3 and MIS 4, with a low sea level, stronger winter Asian Monsoon (AM) and a more southerly subarctic front played important roles in

  3. Organic geochemical investigations of the Dali Lake sediments in northern China: Implications for environment and climate changes of the last deglaciation in the East Asian summer monsoon margin

    Science.gov (United States)

    Fan, Jiawei; Xiao, Jule; Wen, Ruilin; Zhang, Shengrui; Wang, Xu; Cui, Linlin; Yamagata, Hideki

    2017-06-01

    Millennial-scale environment and climate changes in the East Asian summer monsoon margin during the last deglaciation are reconstructed by systematic studies on the characteristic of sedimentary organic matter from Dali Lake in northern China. Concurrent increases in the TOC and TN concentrations indicate increases in terrestrial organic matter and nutrient inputs to the lake and a development of terrestrial vegetation and phytoplankton productivity related to increases in regional temperature and precipitation. C/N ratios reflect changes in the proportions of terrestrial and aquatic organic matter. Decreases in both δ13Corg and δ15N values indicate increases in the isotopically lighter, terrestrial carbon and nitrogen inputs to the lake, due to increases in surface runoffs; while a sharp decrease in the δ15N value implies a significant weakening in the biological activities of nitrifying and amonifying bacteria, due to abrupt decrease in the water temperature. The geochemical data indicate that regional temperature and precipitation exhibited increasing trends from 15,000 to 12,350 cal yr BP; temperature decreased abruptly at 12,350 cal yr BP and then maintained a low level from 12,350 to 11,400 cal yr BP, precipitation decreased to a relatively low level from 12,350 to 11,400 cal yr BP; and both temperature and precipitation returned to increase after 11,400 cal yr BP. The climate change in the Dali Lake region during the last deglaciation corresponds, within age uncertainties, to the Bølling-Allerød (BA) warm phase and Younger Dryas (YD) cold reversal occurring over northern high latitudes. However, the gradual and mild increasing trends of regional temperature and precipitation during the BA warm period contrasts with the general cooling trend in northern high latitude temperature, implying a dominant influence from increases in the Northern Hemisphere summer insolation; while the slight decreases in regional precipitation relative to the rapid and

  4. ARM Climate Research Facility Annual Report 2005

    Energy Technology Data Exchange (ETDEWEB)

    J. Voyles

    2005-12-31

    Through the ARM Program, the DOE funded the development of several highly instrumented ground stations for studying cloud formation processes and their influence on radiative transfer, and for measuring other parameters that determine the radiative properties of the atmosphere. This scientific infrastructure, and resultant data archive, is a valuable national and international asset for advancing scientific knowledge of Earth systems. In fiscal year (FY) 2003, the DOE designated ARM sites as a national scientific user facility: the ARM Climate Research (ACRF). The ACRF has enormous potential to contribute to a wide range interdisciplinary science in areas such as meteorology, atmospheric aerosols, hydrology, biogeochemical cycling, and satellite validation, to name only a few.

  5. The onset and advance of the Asian summer monsoon

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on the daily outgoing longwave radiation (OLR) data from National Oceanic and Atmospheric Administration (NOAA) satellites, the Climate Prediction Center's merged analysis of precipitation (CMAP) data and the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis dataset, the mean intraseasonal variability of the Asian summer monsoon (ASM) is investigated by using power spectrum analysis, band-pass filter, and diagnostic analyses. The processes of the onset and advance of monsoon over the southern part of Indochina Peninsula, the east coast of Bay of Bengal, the South China Sea and the Indian subcontinent are explored. It is found that there is an abrupt change in OLR, precipitation and zonal wind during the onset and advance of the ASM. It is also indicated that the southern part of Indochina Peninsula and the adjacent Andaman Sea is the region where the earliest onset of the ASM occurs in the 2nd pentad of May.

  6. Estimated impact of black carbon deposition during pre-monsoon season from Nepal Climate Observatory – Pyramid data and snow albedo changes over Himalayan glaciers

    Directory of Open Access Journals (Sweden)

    T. J. Yasunari

    2010-07-01

    Full Text Available The possible minimal range of reduction in snow surface albedo due to dry deposition of black carbon (BC in the pre-monsoon period (March–May was estimated as a lower bound together with the estimation of its accuracy, based on atmospheric observations at the Nepal Climate Observatory – Pyramid (NCO-P sited at 5079 m a.s.l. in the Himalayan region. A total BC deposition rate was estimated as 2.89 μg m−2 day−1 providing a total deposition of 266 μg m−2 for March–May at the site, based on a calculation with a minimal deposition velocity of 1.0×10−4 m s−1 with atmospheric data of equivalent BC concentration. Main BC size at NCO-P site was determined as 103.1–669.8 nm by correlation analyses between equivalent BC concentration and particulate size distributions in the atmosphere. The BC deposition from the size distribution data was also estimated. It was found that 8.7% of the estimated dry deposition corresponds to the estimated BC deposition from equivalent BC concentration data. If all the BC is deposited uniformly on the top 2-cm pure snow, the corresponding BC concentration is 26.0–68.2 μg kg−1, assuming snow density variations of 195–512 kg m−3 of Yala Glacier close to NCO-P site. Such a concentration of BC in snow could result in 2.0–5.2% albedo reductions. By assuming these albedo reductions continue throughout the year, and then applying simple numerical experiments with a glacier mass balance model, we estimated reductions would lead to runoff increases of 70–204 mm of water. This runoff is the equivalent of 11.6–33.9% of the annual discharge of a typical Tibetan glacier. Our estimates of BC concentration in snow surface for pre-monsoon season is comparable to those at similar altitudes in the Himalayan region, where glaciers and perpetual snow regions begin, in the vicinity of NCO-P. Our estimates from only BC are likely to

  7. The effect of El-Niño on South Asian Monsoon and agricultural production

    Science.gov (United States)

    Mukherjee, A.

    2015-12-01

    Mukherjee A, Wang S.Y.Abstract:The South Asian Monsoon has a prominent and significant impact on South Asian countries like India, Bangladesh, Nepal, Pakistan, Sri Lanka and it is one of the most studied phenomena in the world. The monsoon is historically known to be influenced by El Niño-Southern Oscillation (ENSO). The inter-annual and inter-decadal variability of seasonal precipitation over India strongly depends upon the ENSO phasing. The average southwest monsoon rainfall received during the years with El Niño was found to be less compared to normal years and the average rainfall during the northeast monsoon is higher in coastal Andhra Pradesh. ENSO is anti-correlated with Indian summer monsoon (ISM). The last prominent effect of ENSO on India's monsoon occurred in 2009 with 23% reduction in annual rainfall, reducing summer sown crops such as rice, sugar cane etc. and pushing up food prices. Climatic resources endowment plays a major role in planning agricultural production in tropical and sub-tropical environment especially under rain-fed agriculture, and so contingent crop planning drawn on this relationship would help to mitigate the effects of ENSO episodes in the region. The unexplored area in this domain of research is the changes in the frequency and intensity of ENSO due to global warming and its impact on ENSO prediction and agricultural management practices. We analyze the last 30 years datasets of Pacific SST, and precipitation and air temperature over Southeast Asia to examine the evolution of ENSO teleconnections with ISM, as well as making estimates of drought indices such as Palmer Drought Severity Index. This research can lead toward better crop management strategies in the South Asian monsoon region.

  8. Joint influence of the Indo-Pacific Warm Pool and Northern Arabian Sea Temperatures on the Indian Summer Monsoon in a Global Climate Model Simulation

    Science.gov (United States)

    Befort, Daniel J.; Leckebusch, Gregor C.; Cubasch, Ulrich

    2016-04-01

    Proxy-based studies confirmed that the Indian Summer Monsoon (ISM) shows large variations during the Holocene. These changes might be explained by changes in orbital conditions and solar insolation but are also thought to be associated to changes in oceanic conditions, e.g. over the Indo-Pacific-Warm-Pool region. However, due to the nature of these (proxy-based) analyses no conclusion about atmospheric circulation changes during dry and wet epochs are possible. Here, a fully-coupled global climate simulation (AOGCM) covering the past 6000 years is analysed regarding ISM variability. Several dry and wet epochs are found, the most striking around 2ka BP (dry) and 1.7ka BP (wet). As only orbital parameters change during integration, we expect these "shorter-term" changes to be associated with changes in oceanic conditions. During 1.7ka BP the sea surface temperatures (SST) over the Northern Arabian Sea (NARAB) are significantly warmer compared to 2ka BP, whereas cooler conditions are found over the western Pacific Ocean. Additionally, significant differences are found over large parts of the North Atlantic. To explain in how far these different ocean basins are responsible for anomalous conditions during 1.7ka BP, several sensitivity experiments with changed SST/SIC conditions are carried out. It is found that neither the SST's in the Pacific nor in the Indian Ocean are able to reproduce the anomalous rainfall and atmospheric circulation patterns during 1.7ka on its own. Instead, anomalous dry conditions during 2ka BP and wet conditions during 1.7ka BP are associated with a shift of the Indo-Pacific-Warm-Pool (IPWP) and simultaneous anomalous sea-surface temperatures over the NARAB region. Eventually, it is tested in how far this hypothesis holds true for other dry and wet events in the AOGCM data during the whole 6000 years. In general, a shift of the IPWP without anomalous SST conditions over the NARAB region (and vice versa) is not sufficient to cause long

  9. "Responding to Climate Change" Course: Research Integration

    Science.gov (United States)

    Pfirman, S. L.; Bowman, J. S.

    2015-12-01

    The "Responding to Climate Change" Barnard/Columbia course integrates current research as well as hands-on research-based activities modified for a classroom environment. The course covers the major response themes of adaptation, mitigation and communication. In the spring of 2015 the course was oriented around Arctic and Antarctic case studies. Each week a different theme is addressed, such as the physical setting, changing ecosystems, governance issues, perspectives of residents and indigenous peoples, geoengineering, commercial interests, security, and health and developmental issues. Frequent guest lectures from thematic experts keep the course grounded in realities and present the students with cutting edge issues. Activities match the weekly theme, for example during the week on Arctic development, students engage with the marine spatial planning simulation Arctic SMARTIC (Strategic Management of Resources in Times of Change) based on research on Arctic sea ice trends and projections coupled with current and projected developmental interests of stakeholders. Created under the Polar Learning and Responding: PoLAR Climate Change Education Partnership (thepolarhub.org), a complete set of SMARTIC resources is available on line for use by others (http://www.camelclimatechange.org/view/article/175297/). The Responding to Climate Change course is designed to be current and respond to events. For the Arctic case study, students developed proposals for the US State Department as the upcoming Chair of the Arctic Council. Student evaluations indicated that they appreciated the opportunity to connect science with policy and presentation of preliminary proposals in a workshop format was valued as a way to develop and hone their ideas. An additional finding was that students were surprisingly tolerant of technical issues when guest lecturers were linked in via Skype, allowing interaction with thematic experts across the US. Students commented positively on this exposure to

  10. On Winning the Race for Predicting the Indian Summer Monsoon Rainfall

    Science.gov (United States)

    Goswami, Bhupendra

    2013-03-01

    Skillful prediction of Indian summer monsoon rainfall (ISMR) one season in advance remains a ``grand challenge'' for the climate science community even though such forecasts have tremendous socio-economic implications over the region. Continued poor skill of the ocean-atmosphere coupled models in predicting ISMR is an enigma in the backdrop when these models have high skill in predicting seasonal mean rainfall over the rest of the Tropics. Here, I provide an overview of the fundamental processes responsible for limited skill of climate models and outline a framework for achieving the limit on potential predictability within a reasonable time frame. I also show that monsoon intra-seasonal oscillations (MISO) act as building blocks of the Asian monsoon and provide a bridge between the two problems, the potential predictability limit and the simulation of seasonal mean climate. The correlation between observed ISMR and ensemble mean of predicted ISMR (R) can still be used as a metric for forecast verification. Estimate of potential limit of predictability of Asian monsoon indicates that the highest achievable R is about 0.75. Improvements in climate models and data assimilation over the past one decade has slowly improved R from near zero a decade ago to about 0.4 currently. The race for achieving useful prediction can be won, if we can push this skill up to about 0.7. It requires focused research in improving simulations of MISO, monsoon seasonal cycle and ENSO-monsoon relationship by the climate models. In order to achieve this goal by 2015-16 timeframe, IITM is leading a Program called Monsoon Mission supported by the Ministry of Earth Sciences, Govt. of India (MoES). As improvement in skill of forecasts can come only if R & D is carried out on an operational modeling system, the Climate Forecast System of National Centre for Environmental Prediction (NCEP) of NOAA, U.S.A has been selected as our base system. The Mission envisages building partnership between

  11. On the atmospheric dynamical responses to land-use change in East Asian monsoon region

    Science.gov (United States)

    Zhang, Huqiang; Gao, Xuejie

    2009-08-01

    This study aims at (1) exploring dominant atmospheric dynamical processes which are responsible for climate model-simulated land-use impacts on Asian monsoon; and (2) assessing uncertainty in such model simulations due to their skills in simulating detailed monsoon circulations in the region. Firstly, results from a series of the Australian Bureau of Meteorology Research Centre (BMRC) global model simulations of land-use vegetation changes (LUC) in China are analysed. The model showed consistent signals of changes in atmospheric low-level vertical profile and regional circulations responding to LUC. In northern winter, the model-simulated rainfall reduction and surface cooling are associated with an enhanced southward penetration of dry and cold air mass, which impedes warm and humid air reaching the region for generating cold-front rainfall. In its summer, an enhanced cyclonic circulation responding to LUC further blocks the northeast penetration of southwestly summer monsoon flow into the region and results in rainfall decreases and a surface warming. Secondly, we have explored uncertainties in the proposed mechanism operating in the global model. By comparing its results with a set of high-resolution regional model simulations using the same vegetation datasets, it reveals similar changes in winter rainfall but opposite features in summer rainfall responses. In the global model, there is a cyclonic low-level circulation pattern over the South China Sea and adjacent region, an unsatisfactory feature commonly seen in other global climate models. With the reduction in surface roughness following LUC, such a deficiency becomes more prominent which further results in a weakened south/southwestly summer monsoon flow and rainfall reduction. In contrast, in the regional model, its southwestly summer monsoon flow is further enhanced due to the same process as reduced surface roughness. The enhanced monsoon flow further pushes the East Asian monsoon rainfall belt more

  12. Late quaternary variability of the Arabian Sea monsoon and oxygen minimum zone

    NARCIS (Netherlands)

    Reichart, Gert-Jan

    1997-01-01

    The Monsoon Among the first Europeans observing the Asiatic monsoon was Alexander the Great during his campaign to the mouth of the Indus (325 B.C.). The oldest known records of the Arabian Sea monsoonal climate, however, are shipping documents, dated about 2300 B.C., which refer to the use of the s

  13. Expanding the Foundation: Climate Change and Opportunities for Educational Research

    Science.gov (United States)

    Henderson, Joseph; Long, David; Berger, Paul; Russell, Constance; Drewes, Andrea

    2017-01-01

    Human-caused climate change is a dominant global challenge. Unlike other disciplines and fields, there has as yet been only limited attention to climate change in educational research generally, and in educational foundations in particular. Education is key to assisting humanity in mitigating and adapting to climate change, and educational…

  14. Systematic errors in Monsoon simulation: importance of the equatorial Indian Ocean processes

    Science.gov (United States)

    Annamalai, H.; Taguchi, B.; McCreary, J. P., Jr.; Nagura, M.; Miyama, T.

    2015-12-01

    H. Annamalai1, B. Taguchi2, J.P. McCreary1, J. Hafner1, M. Nagura2, and T. Miyama2 International Pacific Research Center, University of Hawaii, USA Application Laboratory, JAMSTEC, Japan In climate models, simulating the monsoon precipitation climatology remains a grand challenge. Compared to CMIP3, the multi-model-mean (MMM) errors for Asian-Australian monsoon (AAM) precipitation climatology in CMIP5, relative to GPCP observations, have shown little improvement. One of the implications is that uncertainties in the future projections of time-mean changes to AAM rainfall may not have reduced from CMIP3 to CMIP5. Despite dedicated efforts by the modeling community, the progress in monsoon modeling is rather slow. This leads us to wonder: Has the scientific community reached a "plateau" in modeling mean monsoon precipitation? Our focus here is to better understanding of the coupled air-sea interactions, and moist processes that govern the precipitation characteristics over the tropical Indian Ocean where large-scale errors persist. A series idealized coupled model experiments are performed to test the hypothesis that errors in the coupled processes along the equatorial Indian Ocean during inter-monsoon seasons could potentially influence systematic errors during the monsoon season. Moist static energy budget diagnostics has been performed to identify the leading moist and radiative processes that account for the large-scale errors in the simulated precipitation. As a way forward, we propose three coordinated efforts, and they are: (i) idealized coupled model experiments; (ii) process-based diagnostics and (iii) direct observations to constrain model physics. We will argue that a systematic and coordinated approach in the identification of the various interactive processes that shape the precipitation basic state needs to be carried out, and high-quality observations over the data sparse monsoon region are needed to validate models and further improve model physics.

  15. The role of potential vorticity anomalies in the Somali Jet on Indian Summer Monsoon Intraseasonal Variability

    Science.gov (United States)

    Rai, P.; Joshi, M.; Dimri, A. P.; Turner, A. G.

    2017-08-01

    The climate of the Indian subcontinent is dominated by rainfall arising from the Indian summer monsoon (ISM) during June to September. Intraseasonal variability during the monsoon is characterized by periods of heavy rainfall interspersed by drier periods, known as active and break events respectively. Understanding and predicting such events is of vital importance for forecasting human impacts such as water resources. The Somali Jet is a key regional feature of the monsoon circulation. In the present study, we find that the spatial structure of Somali Jet potential vorticity (PV) anomalies varies considerably during active and break periods. Analysis of these anomalies shows a mechanism whereby sea surface temperature (SST) anomalies propagate north/northwestwards through the Arabian Sea, caused by a positive feedback loop joining anomalies in SST, convection, modification of PV by diabatic heating and mixing in the atmospheric boundary layer, wind-stress curl, and ocean upwelling processes. The feedback mechanism is consistent with observed variability in the coupled ocean-atmosphere system on timescales of approximately 20 days. This research suggests that better understanding and prediction of monsoon intraseasonal variability in the South Asian monsoon may be gained by analysis of the day-to-day dynamical evolution of PV in the Somali Jet.

  16. Promoting Climate Literacy and Enhancing Student Achievement Through a Worldwide Student Research Campaign on Climate Change

    Science.gov (United States)

    Geary, E. E.

    2008-12-01

    In 2011, the GLOBE (Global Learning and Observations to Benefit the Environment) program in collaboration with numerous U.S. and international scientific and educational organizations, will launch a worldwide student research campaign on Climate Change. The goals of the campaign are: (1) to engage over 1 million K-16 students and teachers in collaborative, grade-level appropriate climate research, (2) enhance climate and environmental literacy for students, teachers, parents, and citizens in tens of thousands of communities around the world, and (3) encourage action stewardship on climate-related environmental issues at local and regional levels. "Climate Literacy: Essential Principles and Fundamental Concepts" (NOAA, 2008) will provide a foundation for student learning, research, and stewardship activities. Planning is currently underway between scientists, students, and teachers from around the world to identify the key questions that will guide student research investigations on topics ranging from Climate, Carbon and Energy to Climate, Weather, and Water to Climate and Ecosystems to Climate and Human Health. Once a set of key climate questions and investigation topics have been selected, high quality climate resources including learning activities, data sets, images, models, and professional development modules and courses, will be found, assembled, and made available to Climate Change Campaign participants through the GLOBE Research Collaboratory. The Collaboratory, which is currently under development, will be a virtual learning, research, and collaboration environment that will include easy to use data collection, analysis, sharing, review, and reporting tools as well as tools and services to promote school to school and student-scientist- teacher collaborations. The formal portion of the Climate Campaign will end in 2013 with a high-profile student research conference at which students will share the results of their research and their local and regional

  17. The Finnish research programme on climate change. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Roos, J. [ed.

    1996-12-31

    This is the final report of the Finnish Research Programme on Climate Change (SILMU). This report includes the final results and conclusions made by the individual research groups. The aim of this report is to lay out the research work, and to present the main results and conclusions obtained during the six-year work. The Finnish Research Programme on Climate Change (SILMU) was a multidisciplinary national research programme on climate and global change. The principal goals of SILMU were: (1) to increase our knowledge on climate change, its causes, mechanisms and consequences, (2) to strengthen the research on climate change in Finland, (3) to increase the participation of Finnish researchers in international research programmes, and (4) to prepare and disseminate information for policy makers on adaptation and mitigation. The key areas of the research were: (1) quantification of the greenhouse effect and the magnitude of anticipated climatic changes,(2) assessment of the effects of changing climate on ecosystems, and (3) development of mitigation and adaptation strategies. The research programme started in June 1990, and it comprised more than 80 individual research projects, ranging from atmospheric chemistry to economics. There were approximately two hundred scientists working within the programme in seven universities and eleven research institutions. The research activities that comprise SILMU were grouped into four interdisciplinary subprogrammes: atmosphere, waters, terrestrial ecosystems and integration and human interactions

  18. Asian monsoons in a late Eocene greenhouse world

    Science.gov (United States)

    Licht, A.; van Cappelle, M.; Abels, H. A.; Ladant, J.-B.; Trabucho-Alexandre, J.; France-Lanord, C.; Donnadieu, Y.; Vandenberghe, J.; Rigaudier, T.; Lécuyer, C.; Terry, D., Jr.; Adriaens, R.; Boura, A.; Guo, Z.; Soe, Aung Naing; Quade, J.; Dupont-Nivet, G.; Jaeger, J.-J.

    2014-09-01

    The strong present-day Asian monsoons are thought to have originated between 25 and 22 million years (Myr) ago, driven by Tibetan-Himalayan uplift. However, the existence of older Asian monsoons and their response to enhanced greenhouse conditions such as those in the Eocene period (55-34 Myr ago) are unknown because of the paucity of well-dated records. Here we show late Eocene climate records revealing marked monsoon-like patterns in rainfall and wind south and north of the Tibetan-Himalayan orogen. This is indicated by low oxygen isotope values with strong seasonality in gastropod shells and mammal teeth from Myanmar, and by aeolian dust deposition in northwest China. Our climate simulations support modern-like Eocene monsoonal rainfall and show that a reinforced hydrological cycle responding to enhanced greenhouse conditions counterbalanced the negative effect of lower Tibetan relief on precipitation. These strong monsoons later weakened with the global shift to icehouse conditions 34 Myr ago.

  19. Atmospheric circulation processes contributing to a multidecadal variation in reconstructed and modeled Indian monsoon precipitation

    Science.gov (United States)

    Wu, Qianru; Hu, Qi

    2015-01-01

    analysis of the recently reconstructed gridded May-September total precipitation in the Indian monsoon region for the past half millennium discloses significant variations at multidecadal timescales. Meanwhile, paleo-climate modeling outputs from the National Center for Atmospheric Research Community Climate System Model 4.0 show similar multidecadal variations in the monsoon precipitation. One of those variations at the frequency of 40-50 years per cycle is examined in this study. Major results show that this variation is a product of the processes in that the meridional gradient of the atmospheric enthalpy is strengthened by radiation loss in the high-latitude and polar region. Driven by this gradient and associated baroclinicity in the atmosphere, more heat/energy is generated in the tropical and subtropical (monsoon) region and transported poleward. This transport relaxes the meridional enthalpy gradient and, subsequently, the need for heat production in the monsoon region. The multidecadal timescale of these processes results from atmospheric circulation-radiation interactions and the inefficiency in generation of kinetic energy from the potential energy in the atmosphere to drive the eddies that transport heat poleward. This inefficiency creates a time delay between the meridional gradient of the enthalpy and the poleward transport. The monsoon precipitation variation lags that in the meridional gradient of enthalpy but leads that of the poleward heat transport. This phase relationship, and underlining chasing process by the transport of heat to the need for it driven by the meridional enthalpy gradient, sustains this multidecadal variation. This mechanism suggests that atmospheric circulation processes can contribute to multidecadal timescale variations. Interactions of these processes with other forcing, such as sea surface temperature or solar irradiance anomalies, can result in resonant or suppressed variations in the Indian monsoon precipitation.

  20. Climate Research Wageningen UR : Projects, researchers and expertise

    NARCIS (Netherlands)

    Loon-Steensma, van J.M.; Vellinga, P.; Remme, R.

    2009-01-01

    Wageningen UR focuses not only on the global climate system but also on regional and local climate phenomena, taking both scientific and social aspects into account in an integral way. Wageningen UR wants to play an effective role in the transition to a world that is both climate neutral and climate

  1. Reappraisal of Asian Summer Monsoon Indices and the Long-Term Variation of Monsoon

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Webster and Yang monsoon index (WYI)-the zonal wind shear between 850 and 200 hPa was calculated and modified on the basis of NCEP/NCAR reanalysis data. After analyzing the circulation and divergence fields of 150-100 and 200 hPa, however, we found that the 200-hPa level could not reflect the real change of the upper-tropospheric circulation of Asian summer monsoon, especially the characteristics and variation of the tropical easterly jet which is the most important feature of the upper-tropospheric circulation. The zonal wind shear U850-U(150+100) is much larger than U850-U200, and thus it can reflect the strength of monsoon more appropriately. In addition, divergence is the largest at 150 hPa rather than 200 hPa, so 150 hPa in the upper-troposphere can reflect the coupling of the monsoon system. Therefore,WYI is redefined as DHI, i.e., IDH=U*850 - U*(150+100), which is able to characterize the variability of not only the intensity of the center of zonal wind shear in Asia, but also the monsoon system in the upper and lower troposphere. DHI is superior to WYI in featuring the long-term variation of Asian summer monsoon as it indicates there is obvious interdecadal variation in the Asian summer monsoon and the climate abrupt change occurred in 1980. The Asian summer monsoon was stronger before 1980 and it weakened after then due to the weakening of the easterly in the layer of 150-100 hPa, while easterly at 200 hPa did not weaken significantly. After the climate jump year in general, easterly in the upper troposphere weakened in Asia, indicating the weakening of summer monsoon; the land-sea pressure difference and thermal difference reduced, resulting in the weakening of monsoon; the corresponding upper divergence as well as the water vapor transport decreased in Indian Peninsula, central Indo-China Peninsula, North China, and Northeast China, indicating the weakening of summer monsoon as well. The difference between NCEP/NCAR and ERA-40 reanalysis data in

  2. Past dynamics of the Australian monsoon: precession, phase and links to the global monsoon concept

    Science.gov (United States)

    Beaufort, L.; van der Kaars, S.; Bassinot, F. C.; Moron, V.

    2010-10-01

    Past variations in the dynamics of the Australian monsoon have been estimated from multi-proxy analysis of a core retrieved in the Eastern Banda Sea. Records of coccolith and pollen assemblages, spanning the last 150 000 years, allow reconstruction of past primary production in the Banda Sea, summer moisture availability, and the length of the dry season in northern Australia and southeastern Indonesia. The amount of moisture available during the summer monsoon follows typical glacial/interglacial dynamics with a broad asymmetrical 100-kyr cycle. Primary production and length of the dry season appear to be closely related, given that they follow the precessional cycle with the same phase. This indicates their independence from ice-volume variations. The present inter-annual variability of both parameters is related to El Niño Southern Oscillation (ENSO), which modulates the Australian Winter Monsoon (AWM). The precessional pattern observed in the past dynamics of the AWM is found in ENSO and monsoon records of other regions. A marked shift in the monsoon intensity occurring during the mid Holocene during a period of constant ice volume, suggests that low latitude climatic variation precedes increases in global ice volume. This precessional pattern suggests that a common forcing mechanism underlies low latitude climate dynamics, acting specifically and synchronously on the different monsoon systems.

  3. Past dynamics of the Australian monsoon: precession, phase and links to the global monsoon

    Science.gov (United States)

    Beaufort, L.; van der Kaars, S.; Bassinot, F. C.; Moron, V.

    2010-06-01

    Past variations in the dynamics of the Australian monsoon have been estimated from multi-proxy analysis of a core retrieved in the Eastern Banda Sea. Records of coccolith and pollen assemblages, spanning the last 150,000 years, allow reconstruction of past primary production in the Banda Sea, summer moisture availability, and the length of the dry season in Northern Australia and Southeastern Indonesia. The amount of moisture available during the summer monsoon follows typical glacial/interglacial dynamics with a broad asymmetrical 100-kyr cycle. Primary production and length of the dry season appear to be closely related, given that they follow the precessional cycle with the same phase (August insolation). This indicates their independence from ice-volume variations. The present inter-annual variability of both parameters is related to El Niño Southern Oscillation (ENSO), which modulates the Australian Winter Monsoon (AWM). The precessional pattern observed in the past dynamics of the AWM is found in ENSO and monsoon records of other regions. A marked shift in the monsoon intensity occurring during the mid Holocene during a period of constant ice volume, suggest that low latitude climatic variation precedes global ice volume. This precessional pattern suggests that a common forcing mechanism underlies low latitude climate dynamics, acting specifically and synchronically on the different monsoon systems.

  4. Interannual variability of South American monsoon circulation

    Science.gov (United States)

    Alonso Gan, Manoel; Rafaele Araújo Lima, Jeane

    2016-04-01

    The South America Monsoon System (SAMS) is responsible for influencing the atmospheric circulation and precipitation over most of tropical South America (SA) during the summer season. Studies for aiming to understand the temporal variability of this system have great value to the scientific community, because the processes that control the monsoon climate are not totally clear. Thus, the main objective of this research is to investigate the possible large-scale climatic factors and the remote interaction mechanisms, which may be associated with summer season interannual variability focusing on identifying the main differences between dry and wet extremes rainy season in the South-eastern Amazon Basin (SAB), Central-West (WC) and Southeast (SE) of Brazil, which are areas influenced by the summer monsoon regime. For such analyzes, Pearson correlations, quantile method and composite analysis were used during the period from 1979 to 2014. The correlation between precipitation anomaly in SAB and the sea surface temperature anomaly (SSTA) and wind at 850hPa and 300hPa indicate El Niño-Southern Oscillation (ENSO) influence. Precipitation anomalies in WC did not show significant correlation with SSTA. However, a pattern similar to ENSO Modoki type was observed in the composite analysis. At 850 hPa, the presence of an anomalous cyclonic (anticyclonic) circulation was observed over the central region of SA during wet (dry) summers seasons. Over SE region of Brazil, a dipole SSTA pattern over the South Atlantic was identified, as well the presence of anomalous circulations with an equivalent barotropic structure over these SSTA areas. This pattern is more evident in case of dry summer on the SE. At 300 hPa, the wave train between 30°S-60°S was observed presenting a feature curvature from 120°W reaching SA, similar to the Pacific-South American pattern (PSA). Analysis of the summer interannual variability indicated the manifestation of wet summers more frequently than dry

  5. Monsoons, history of

    Digital Repository Service at National Institute of Oceanography (India)

    Niitsuma, N.; Naidu, P.D.

    The evolution of the Asian monsoon started at around 9.5 Ma, in response to the uplift of the Himalayas. The monsoonal intensity reached its maximum at around 5 Ma, and from that time the associated easterly trade winds caused intense upwelling...

  6. North American Monsoon Variability from Instrumental and Tree-Ring Data: A Progress Report (Invited)

    Science.gov (United States)

    Woodhouse, C. A.; Meko, D. M.; Touchan, R.; Leavitt, S. W.; Griffin, D.; Castro, C. L.; Ciancarelli, B.

    2009-12-01

    The main goal of this research project is to investigate the long-term variability of the North American Monsoon (NAM), both spatially and temporally, using instrumental data and paleoclimatic data from tree-ring widths and stable-carbon isotopes. The NAM has been the topic of much research in recent years and a great deal of progress has been made in improving our understanding of the NAM. However, questions remain about the long-term behavior of the monsoon, as well as its relationship to cool season climate and to large-scale circulation. In addition, it is unclear how the monsoon will respond to global warming as GCMs do not yet appear to adequately capture the monsoon system dynamics. This research project involves analyses of instrumental and paleoclimatic data to determine NAM spatial patterns in the U.S., relationships to large-scale atmospheric circulation drivers, and the nature of the NAM variability over past centuries. Paleoclimatic data will also be used to assess the skill of downscaled GCMs in replicating the range of NAM variability. The first step in this work has been to design and implement a sampling and analysis strategy for a network of tree-ring data that reflects summer moisture in the NAM region, informed by previous collections and analysis of instrumental data. Here we report on the results from our first year, focusing on three specific areas: 1) definition of dominant patterns of NAM variability using the standard precipitation index (SPI), and relationships to large-scale atmospheric circulation, 2) the tree-ring collection network and preliminary results, and 3) strategies for enhancing and extracting summer precipitation information from tree rings using partial ring widths and isotope analysis. Although our collections have included both the monsoon core region of southeastern Arizona and southwestern New Mexico, and areas at the fringe of the monsoon influence in the U.S, our initial focus is on the analysis of the collections for

  7. Atmospheric Radiation Measurement (ARM) Climate Research Facility Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Mather, James [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-04-01

    Mission and Vision Statements for the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Mission The ARM Climate Research Facility, a DOE scientific user facility, provides the climate research community with strategically located in situ and remote-sensing observatories designed to improve the understanding and representation, in climate and earth system models, of clouds and aerosols as well as their interactions and coupling with the Earth’s surface. Vision To provide a detailed and accurate description of the Earth atmosphere in diverse climate regimes to resolve the uncertainties in climate and Earth system models toward the development of sustainable solutions for the nation's energy and environmental challenges.

  8. The Cloud Project Climate Research with Accelerators

    CERN Document Server

    Kirkby, Jasper

    2010-01-01

    The current understanding of climate change in the in- dustrial age is that it is predominantly caused by anthro- pogenic greenhouse gases, with relatively small natural contributions due to solar irradiance and volcanoes. How- ever, palaeoclimatic reconstructions show that the climate has frequently varied on 100-year time scales during the Holocene (last 10 kyr) by amounts comparable to the present warming—and yet the mechanism is not under- stood. Estimated changes of solar irradiance on these time scales are too small to account for the climate observations. This raises the question of whether cosmic rays, which are modulated by the solar wind, may be directly affect- ing the climate, providing an effective indirect solar forcing mechanism. Indeed recent satellite observations—although disputed—suggest that cosmic rays may affect clouds un- der certain conditions. However, given the many sources of variability in the atmosphere and the lack of control of the cosmic ray flux, demonstrating overall ca...

  9. Teachers Learning to Research Climate: Development of hybrid teacher professional development to support climate inquiry and research in the classroom

    Science.gov (United States)

    Odell, M. R.; Charlevoix, D. J.; Kennedy, T.

    2011-12-01

    The GLOBE Program is an international science and education focused on connecting scientists, teachers and students around relevant, local environmental issues. GLOBE's focus during the next two years in on climate, global change and understanding climate from a scientific perspective. The GLOBE Student Climate Research Campaign (SCRFC) will engage youth from around the world in understanding and researching climate through investigations of local climate challenges. GLOBE teachers are trained in implementation of inquiry in the classroom and the use of scientific data collection protocols to develop inquiry and research projects of the Earth System. In preparation for the SCRC, GLOBE teachers will need additional training in climate science, global change and communicating climate science in the classroom. GLOBE's reach to 111 countries around the world requires development of scalable models for training teachers. In June GLOBE held the first teacher professional development workshop (Learning to Research Summer Institute) in a hybrid format with two-thirds of the teachers participating face-to-face and the remaining teachers participating virtually using Adobe Connect. The week long workshop prepared teachers to integrate climate science inquiry and research projects in the classrooms in the 2011-12 academic year. GLOBE scientists and other climate science experts will work with teachers and their students throughout the year in designing and executing a climate science research project. Final projects and research results will be presented in May 2012 through a virtual conference. This presentation will provide the framework for hybrid teacher professional development in climate science research and inquiry projects as well as summarize the findings from this inaugural session. The GLOBE Program office, headquartered in Boulder, is funded through cooperative agreements with NASA and NOAA with additional support from NSF and the U.S. Department of State. GLOBE

  10. Stable isotopes in monsoon precipitation and water vapour in Nagqu, Tibet, and their implications for monsoon moisture

    Science.gov (United States)

    He, Siyuan; Richards, Keith

    2016-09-01

    Understanding climate variations over the Qinghai-Tibetan plateau has become essential because the high plateau sustains various ecosystems and water sources, and impacts on the Asian monsoon system. This paper provides new information from isotopic signals in meteoric water and atmospheric water vapour on the Qinghai-Tibetan Plateau using high frequency observation data over a relatively short period. The aim is to explore temporal moisture changes and annual variations at the onset and during the summer monsoon season at a transitional site with respect to the monsoon influence. Data show that high frequency and short period observations can reveal typical moisture changes from the pre-monsoon to the monsoon seasons (2010), and the large variation in isotopic signals in different years with respect to active/inactive periods during a mature phase of the monsoon (2011), especially inferring from the temporal changes in the d-excess of precipitation and its relationship with δ18O values, when higher d-excess is found in the pre-monsoon precipitation. In this transition zone on a daily basis, δ18O values in precipitation are controlled mainly by the amount of rainfall during the monsoon season, while temperature seems more important before the onset of monsoon. Furthermore, the "amount effect" is significant for night-time rain events. From comparison of signals in both the precipitation and water vapour, an inconsistent relationship between d-excess values suggests various moisture fluxes are active in a short period. The temporal pattern of isotopic signal change from the onset of the monsoon to the mature monsoon phase provides information about the larger circulation dynamics of the Asian monsoon.

  11. Denying bogus skepticism in climate change and tourism research

    NARCIS (Netherlands)

    Hall, C.M.; Amelung, B.; Cohen, S.; Leemans, R.; Lamers, M.A.J.; Long, P.

    2015-01-01

    This final response to the two climate change denial papers by Shani and Arad further highlights the inaccuracies, misinformation and errors in their commentaries. The obfuscation of scientific research and the consensus on anthropogenic climate change may have significant long-term negative

  12. Denying bogus skepticism in climate change and tourism research

    NARCIS (Netherlands)

    Hall, C.M.; Amelung, B.; Cohen, S.; Leemans, R.; Lamers, M.A.J.; Long, P.

    2015-01-01

    This final response to the two climate change denial papers by Shani and Arad further highlights the inaccuracies, misinformation and errors in their commentaries. The obfuscation of scientific research and the consensus on anthropogenic climate change may have significant long-term negative consequ

  13. Relationship Between East Asian Winter Monsoon and Summer Monsoon

    Institute of Scientific and Technical Information of China (English)

    YAN Hongming; YANG Hui; YUAN Yuan; LI Chongyin

    2011-01-01

    Using National Centers for Environmental Prediction/National Centre for Atmospheric Research (NCEP/NCAR) reanalysis data and monthly Hadley Center sea surface temperature (SST) data,and selecting a representative East Asian winter monsoon (EAWM) index,this study investigated the relationship between EAWM and East Asian summer monsoon (EASM) using statistical analyses and numerical simulations.Some possible mechanisms regarding this relationship were also explored.Results indicate a close relationship between EAWM and EASM:a strong EAWM led to a strong EASM in the following summer,and a weak EAWM led to a weak EASM in the following summer.Anomalous EAWM has persistent impacts on the variation of SST in the tropical Indian Ocean and the South China Sea,and on the equatorial atmospheric thermal anomalies at both lower and upper levels.Through these impacts,the EAWM influences the land-sea thermal contrast in summer and the low-level atmospheric divergence and convergence over the Indo-Pacific region.It further affects the meridional monsoon circulation and other features of the EASM.Numerical simulations support the results of diagnostic analysis.The study provides useful information for predicting the EASM by analyzing the variations of preceding EAWM and tropical SST.

  14. High Resolution δ18O and δ13C Records of AMS 14C Dated Stalagmites From Jinlun and Yilingyan Caves in Guangxi, China: Climate Variability and Controlling Factors in the Monsoonal Region During the Past 2300 Years

    Science.gov (United States)

    Li, H. C.; Lien, W. Y.; Mii, H. S.; Jiang, G. H.; Chou, C. Y.; Chou, P. J.

    2015-12-01

    Jinlun Cave in Mashan County and Yilingyan Cave in Wuming County are ~120km and ~60km north of Nanning in Guangxi Province under influence of both Indian Monsoon and North Western Pacific Monsoon. Several stalagmites have been dated by AMS 14C dating method since 230Th/U is not applicable due to very low U contents. Twenty (20) AMS 14C dates on Stalagmite JL20131005-10 (10-cm long) show "Bomb carbon curve", spanning the past 60 years. Lamination counting further confirms the chronology. Thirty nine (39) AMS 14C dates on Stalagmite JL20131005-12 (33-cm long) reveal 2300-year continuous growth. Stalagmite YLY20130727-12 (10-cm long) from Yilingyan Cave covers a continuous record of past 2300 years. All studied stalagmites in the caves contain low dead carbon fractions. The annual resolution δ18O and δ13C records obtained from the stalagmites allow us to compare the stalagmite δ18O records with the instrumental rainfall and temperature records, Pacific Decadal Oscillation (PDO), Southern Oscillation Index (SOI), and Sunspot variation, etc. The δ18O and δ13C records exhibit relatively good correlation throughout the time, indicating climatic control on vegetation change. Based on the high-resolution δ18O and δ13C records, we interpret that dry climatic conditions and poor vegetation coverage during periods of AD1880~1850, 1700~1600, 1460~1320, 1210~1280, 860~750, 540~420, 300~220, and AD100~0 shown by increased δ18O and δ13C. The δ18O and δ13C were strongly depleted during the Medieval Warm Period (MWP between AD900 and AD1100) and Current Warm Period (CWP, since AD1900), reflecting strongly increased East Asian Summer Monsoon. After AD1900, the δ13C decreased about 6‰, perhaps indicating human impact on surface vegetation. The δ18O records from the study area are comparable to the published WX42B δ18O record of Wanxiang Cave (Zhang et al., 2008) except for the period of AD1400~1850. Our study suggests that AMS 14C dating is an alternative method for

  15. Autoencoder-based identification of predictors of Indian monsoon

    Science.gov (United States)

    Saha, Moumita; Mitra, Pabitra; Nanjundiah, Ravi S.

    2016-10-01

    Prediction of Indian summer monsoon uses a number of climatic variables that are historically known to provide a high skill. However, relationships between predictors and predictand could be complex and also change with time. The present work attempts to use a machine learning technique to identify new predictors for forecasting the Indian monsoon. A neural network-based non-linear dimensionality reduction technique, namely, the sparse autoencoder is used for this purpose. It extracts a number of new predictors that have prediction skills higher than the existing ones. Two non-linear ensemble prediction models of regression tree and bagged decision tree are designed with identified monsoon predictors and are shown to be superior in terms of prediction accuracy. Proposed model shows mean absolute error of 4.5 % in predicting the Indian summer monsoon rainfall. Lastly, geographical distribution of the new monsoon predictors and their characteristics are discussed.

  16. Integrating climate change into agricultural research for development in Africa

    Energy Technology Data Exchange (ETDEWEB)

    Chambwera, Muyeye; Anderson, Simon

    2011-09-15

    African agriculture is already struggling to meet increasing demand for food. Climate change, which will alter agroecological conditions and looks set to arrest and decrease agricultural yields on the continent, will make it even harder to achieve food security. Boosting agricultural productivity in Africa, especially in the face of climate change, cannot be achieved without the benefits of cutting edge science. Advances in technology development and transfer, capacity building and policy research must be harnessed by developing and disseminating relevant strategies and technologies, and improving policy environments. The European Initiative for Agricultural Research for Development (EIARD), which facilitates and coordinates European policy and support for agricultural research for development, must integrate climate change into its activities and ensure that agricultural research for development and climate change adaptation are not disjointed. This demands a more strategic and coordinated approach from the initiative — one that reflects African realities, responds to African priorities for adaptation and development, and makes the best use of limited resources.

  17. Global climate change: Social and economic research issues

    Energy Technology Data Exchange (ETDEWEB)

    Rice, M.; Snow, J.; Jacobson, H. [eds.

    1992-05-01

    This workshop was designed to bring together a group of scholars, primarily from the social sciences, to explore research that might help in dealing with global climate change. To illustrate the state of present understanding, it seemed useful to focus this workshop on three broad questions that are involved in coping with climate change. These are: (1) How can the anticipated economic costs and benefits of climate change be identified; (2) How can the impacts of climate change be adjusted to or avoided; (3) What previously studied models are available for institutional management of the global environment? The resulting discussions may (1) identify worthwhile avenues for further social science research, (2) help develop feedback for natural scientists about research information from this domain needed by social scientists, and (3) provide policymakers with the sort of relevant research information from the social science community that is currently available. Individual papers are processed separately for the database.

  18. Roadmap towards justice in urban climate adaptation research

    Science.gov (United States)

    Shi, Linda; Chu, Eric; Anguelovski, Isabelle; Aylett, Alexander; Debats, Jessica; Goh, Kian; Schenk, Todd; Seto, Karen C.; Dodman, David; Roberts, Debra; Roberts, J. Timmons; Vandeveer, Stacy D.

    2016-02-01

    The 2015 United Nations Climate Change Conference in Paris (COP21) highlighted the importance of cities to climate action, as well as the unjust burdens borne by the world's most disadvantaged peoples in addressing climate impacts. Few studies have documented the barriers to redressing the drivers of social vulnerability as part of urban local climate change adaptation efforts, or evaluated how emerging adaptation plans impact marginalized groups. Here, we present a roadmap to reorient research on the social dimensions of urban climate adaptation around four issues of equity and justice: (1) broadening participation in adaptation planning; (2) expanding adaptation to rapidly growing cities and those with low financial or institutional capacity; (3) adopting a multilevel and multi-scalar approach to adaptation planning; and (4) integrating justice into infrastructure and urban design processes. Responding to these empirical and theoretical research needs is the first step towards identifying pathways to more transformative adaptation policies.

  19. A statistically predictive model for future monsoon failure in India

    Science.gov (United States)

    Schewe, Jacob; Levermann, Anders

    2012-12-01

    Indian monsoon rainfall is vital for a large share of the world’s population. Both reliably projecting India’s future precipitation and unraveling abrupt cessations of monsoon rainfall found in paleorecords require improved understanding of its stability properties. While details of monsoon circulations and the associated rainfall are complex, full-season failure is dominated by large-scale positive feedbacks within the region. Here we find that in a comprehensive climate model, monsoon failure is possible but very rare under pre-industrial conditions, while under future warming it becomes much more frequent. We identify the fundamental intraseasonal feedbacks that are responsible for monsoon failure in the climate model, relate these to observational data, and build a statistically predictive model for such failure. This model provides a simple dynamical explanation for future changes in the frequency distribution of seasonal mean all-Indian rainfall. Forced only by global mean temperature and the strength of the Pacific Walker circulation in spring, it reproduces the trend as well as the multidecadal variability in the mean and skewness of the distribution, as found in the climate model. The approach offers an alternative perspective on large-scale monsoon variability as the result of internal instabilities modulated by pre-seasonal ambient climate conditions.

  20. Warm Indian Ocean, Weak Asian Monsoon

    Science.gov (United States)

    Koll Roxy, Mathew; Ritika, Kapoor; Terray, Pascal; Murtugudde, Raghu; Ashok, Karumuri; Nath Goswami, Buphendra

    2015-04-01

    There are large uncertainties looming over the status and fate of the South Asian monsoon in a changing climate. Observations and climate models have suggested that anthropogenic warming in the past century has increased the moisture availability and the land-sea thermal contrast in the tropics, favoring an increase in monsoon rainfall. In contrast, we notice that South Asian subcontinent experienced a relatively subdued warming during this period. At the same time, the tropical Indian Ocean experienced a nearly monotonic warming, at a rate faster than the other tropical oceans. Using long-term observations and coupled model experiments, we suggest that the enhanced Indian Ocean warming along with the suppressed warming of the subcontinent weaken the land-sea thermal contrast throughout the troposphere, dampen the monsoon Hadley circulation, and reduce the rainfall over South Asia. As a result, the summer monsoon rainfall during 1901-2012 shows a significant weakening trend over South Asia, extending from Pakistan through central India to Bangladesh.

  1. Advancing Australia's role in climate change and health research

    Science.gov (United States)

    Green, Donna; Pitman, Andrew; Barnett, Adrian; Kaldor, John; Doherty, Peter; Stanley, Fiona

    2017-02-01

    A major Australian government report published 25 years ago called for urgent investment in research on the impacts of climate change on human health. Since that report's release, less than 0.1% of Australian health funding has been allocated to this area. As the world continues on a high emissions pathway, the health impacts from climate change are increasing in size and complexity. While Australia has established leadership roles in climate science and health research, it must now link these two strengths. Doing so would boost regional understanding of how climate change will affect health and what adaptation strategies are needed to reduce these threats. Such research would support better health planning and decision-making in partnership with other regional countries.

  2. Research progress of extreme climate and its vegetation response

    Science.gov (United States)

    Cui, Xiaolin; Wei, Xiaoqing; Wang, Tao

    2017-08-01

    The IPCC’s fifth assessment report indicates that climate warming is unquestionable, the frequency and intensity of extreme weather events may increase, and extreme weather events can destroy the growth conditions of vegetation that is otherwise in a stable condition. Therefore, it is essential to research the formation of extreme weather events and its ecological response, both in terms scientific development and the needs of societal development. This paper mainly examines these issues from the following aspects: (1) the definition of extreme climate events and the methods of studying the associated response of vegetation; (2) the research progress on extreme climate events and their vegetation response; and (3) the future direction of research on extreme climate and its vegetation response.

  3. Relationships between the Survey of Organizational Research Climate (SORC) and self-reported research practices.

    Science.gov (United States)

    Crain, A Lauren; Martinson, Brian C; Thrush, Carol R

    2013-09-01

    The Survey of Organizational Research Climate (SORC) is a validated tool to facilitate promotion of research integrity and research best practices. This work uses the SORC to assess shared and individual perceptions of the research climate in universities and academic departments and relate these perceptions to desirable and undesirable research practices. An anonymous web- and mail-based survey was administered to randomly selected biomedical and social science faculty and postdoctoral fellows in the United States. Respondents reported their perceptions of the research climates at their universities and primary departments, and the frequency with which they engaged in desirable and undesirable research practices. More positive individual perceptions of the research climate in one's university or department were associated with higher likelihoods of desirable, and lower likelihoods of undesirable, research practices. Shared perceptions of the research climate tended to be similarly predictive of both desirable and undesirable research practices as individuals' deviations from these shared perceptions. Study results supported the central prediction that more positive SORC-measured perceptions of the research climate were associated with more positive reports of research practices. There were differences with respect to whether shared or individual climate perceptions were related to desirable or undesirable practices but the general pattern of results provide empirical evidence that the SORC is predictive of self-reported research behavior.

  4. Response of Modern Monsoon Temperate Glacier to Climate Change in Yulong Mountain%玉龙雪山现代季风温冰川对气候变化的响应

    Institute of Scientific and Technical Information of China (English)

    杜建括; 辛惠娟; 何元庆; 牛贺文; 蒲焘; 曹伟宏; 张涛

    2013-01-01

    Sensitive responding to climate change is the most remarkable feature of monsoon temperate glaciers,as the most direct and brightest indicator of climate change it would substantially go forward or backward by a weak change of temperature.This article selects Yulong Mountain as research region,which is the southernmost temperate glacier region at present in China and Eurasian continent.Based on field observation data and remote sensing data,combining previous research results,the response process of Yulong Mountain to climatic change is emphatically analyzed.Additionally,this article especially studies the area,shape,temperature,width,and terminus etc variation of Baishui No.1 glacier,and discusses the main causes of glacial changes.The result was as follows:1) Glaciers retreat was continuous and obvious in Yulong Mountain.Compared with 19 glaciers with total area of 11.6 km2 in 1957,6 glaciers had disappeared completely,and only 13 glaciers exist at present,with a total area of 5.30 km2 in 2001 and 4.42 km2 in 2009.The changing rate of glacier area was-1.19% in 1957-2009,which was much faster than that of other typical glacier region in China.2)Compared with 1982,the quantity of the Baishui No.lglacier crevasses increased and their scales also extend in the context of global climate change,the body of glacier had ruptured on the firn basin.A series of massive crevasses had formed on the glacier surface since 2011.Meanwhile,the.ice river/lake had appeared since 2008,glacial ablation was much intense.3) The glacier terminus elevation displayed rising state overall in 1982-2011,and the rising amplitude had increased since 1999.The retreat speed of Baishui No.1 glacier was 8.8 m/a in 1982-2011,and increased to 13.8 m/a in 1999-2011.4) The lowest temperature from glacier surface to 8 m depth at the ablation area was-0.8℃ in 1982,and rising to-0.39℃ in 2009.Rising glacier temperature caused melt speed of the ice accelerate and mass balance loss intensifying.5) The

  5. Soil moisture initialization effects in the Indian monsoon system

    OpenAIRE

    Asharaf, S.; A. Dobler; Ahrens, B.

    2011-01-01

    Towards the goal to understand the role of land-surface processes over the Indian sub-continent, a series of soil-moisture sensitivity simulations have been performed using a non-hydrostatic regional climate model COSMO-CLM. The experiments were driven by the lateral boundary conditions provided by the ERA-Interim (ECMWF) reanalysis. The simulation results show that the pre-monsoonal soil moisture has a significant influence on the monsoonal precipitation. Both, positive and negative soil-moi...

  6. Predictor-Year Subspace Clustering Based Ensemble Prediction of Indian Summer Monsoon

    Directory of Open Access Journals (Sweden)

    Moumita Saha

    2016-01-01

    Full Text Available Forecasting the Indian summer monsoon is a challenging task due to its complex and nonlinear behavior. A large number of global climatic variables with varying interaction patterns over years influence monsoon. Various statistical and neural prediction models have been proposed for forecasting monsoon, but many of them fail to capture variability over years. The skill of predictor variables of monsoon also evolves over time. In this article, we propose a joint-clustering of monsoon years and predictors for understanding and predicting the monsoon. This is achieved by subspace clustering algorithm. It groups the years based on prevailing global climatic condition using statistical clustering technique and subsequently for each such group it identifies significant climatic predictor variables which assist in better prediction. Prediction model is designed to frame individual cluster using random forest of regression tree. Prediction of aggregate and regional monsoon is attempted. Mean absolute error of 5.2% is obtained for forecasting aggregate Indian summer monsoon. Errors in predicting the regional monsoons are also comparable in comparison to the high variation of regional precipitation. Proposed joint-clustering based ensemble model is observed to be superior to existing monsoon prediction models and it also surpasses general nonclustering based prediction models.

  7. How Agribusiness Uses Climate Predictions: Implications for Climate Research and Provision of Predictions.

    Science.gov (United States)

    Sonka, S. T.; Changnon, S. A., Jr.; Hofing, S. L.

    1992-12-01

    The paper presents an analysis of climate prediction needs and uses within six important subsegments of the agribusiness sector. Results are based on a mail survey of 114 managers. Although nearly 70% of the respondents indicated some use of climate predictions in the last year, only 1 in 8 of the respondents used that information in a specific decision. Lack of sufficient accuracy and prediction lead time were identified as two important impediments to current use of climate predictions. Estimates of necessary accuracy levels and lead time are reported both for the group average and by segments of need. Recommendations are offered regarding research needs to enhance climate prediction and activities of the government and the private sector to improve use of climate predictions.

  8. Decadal/interdecadal variations of the ocean temperature and its impacts on climate

    Science.gov (United States)

    Li, Chongyin; Zhou, Wen; Jia, Xiaolong; Wang, Xin

    2006-12-01

    Decadal/interdecadal climate variability is an important research focus of the CLIVAR Program and has been paid more attention. Over recent years, a lot of studies in relation to interdecadal climate variations have been also completed by Chinese scientists. This paper presents an overview of some advances in the study of decadal/interdecadal variations of the ocean temperature and its climate impacts, which includes interdecadal climate variability in China, the interdecadal modes of sea surface temperature (SST) anomalies in the North Pacific, and in particular, the impacts of interdecadal SST variations on the Asian monsoon rainfall. As summarized in this paper, some results have been achieved by using climate diagnostic studies of historical climatic datasets. Two fundamental interdecadal SST variability modes (7 10-years mode and 25 35-years mode) have been identified over the North Pacific associated with different anomalous patterns of atmospheric circulation. The southern Indian Ocean dipole (SIOD) shows a major feature of interdecadal variation, with a positive (negative) phase favoring a weakened (enhanced) Asian summer monsoon in the following summer. It is also found that the China monsoon rainfall exhibits interdecadal variations with more wet (dry) monsoon years in the Yangtze River (South China and North China) before 1976, but vice versa after 1976. The weakened relationship between the Indian summer rainfall and ENSO is a feature of interdecadal variations, suggesting an important role of the interdecadal variation of the SIOD in the climate over the south Asia and southeast Asia. In addition, evidence indicates that the climate shift in the 1960s may be related to the anomalies of the North Atlantic Oscillation (NAO) and North Pacific Oscillation (NPO). Overall, the present research has improved our understanding of the decadal/interdecadal variations of SST and their impacts on the Asian monsoon rainfall. However, the research also highlights a

  9. Centennial to millennial climate variability in the far northwestern Pacific (off Kamchatka and its linkage to the East Asian monsoon and North Atlantic from the Last Glacial Maximum to the early Holocene

    Directory of Open Access Journals (Sweden)

    S. A. Gorbarenko

    2017-08-01

    Full Text Available High-resolution reconstructions based on productivity proxies and magnetic properties of core LV63-41-2 (off Kamchatka reveal prevailing centennial productivity/climate variability in the northwestern (NW Pacific from the Last Glacial Maximum (LGM to the early Holocene (EH. The age model of the core is established by AMS 14C dating and by projections of AMS 14C data of the nearby core SO-201-12KL through correlation of the productivity proxies and relative paleomagnetic intensity. The resulting sequence of centennial productivity increases/climate warming events in the NW Pacific occurred synchronously with the East Asian summer monsoon (EASM sub-interstadials during the LGM (four events, Heinrich Event 1 (HE1 (four events, Bølling–Allerød (B/A warming (four events, and over the EH (four events. Remarkable similarity of the sequence of the NW Pacific increased-productivity events with the EASM sub-interstadials over the LGM-HE1 implies that the Siberian High is a strong and common driver. The comparison with the δ18O record from Antarctica suggests that another mechanism associated with the temperature gradient in the Southern Hemisphere may also be responsible for the EASM/NW Pacific centennial events over the LGM-HE1. During the B/A warming and resumption of the Atlantic Meridional Overturning Circulation (AMOC, clear synchronicity between the NW Pacific, EASM and Greenland sub-interstadials was mainly controlled by changes in the atmospheric circulation. During the EH the linkages between solar forcing, ocean circulation, and climate changes likely control the synchronicity of abrupt climate changes in the NW Pacific and North Atlantic. The sequence of centennial events recorded in this study is a persistent regional feature during the LGM-EH, which may serve as a template in high-resolution paleoceanography and sediment stratigraphy in the NW Pacific.

  10. Climate change, human health, and biomedical research: analysis of the National Institutes of Health research portfolio.

    Science.gov (United States)

    Jessup, Christine M; Balbus, John M; Christian, Carole; Haque, Ehsanul; Howe, Sally E; Newton, Sheila A; Reid, Britt C; Roberts, Luci; Wilhelm, Erin; Rosenthal, Joshua P

    2013-04-01

    According to a wide variety of analyses and projections, the potential effects of global climate change on human health are large and diverse. The U.S. National Institutes of Health (NIH), through its basic, clinical, and population research portfolio of grants, has been increasing efforts to understand how the complex interrelationships among humans, ecosystems, climate, climate variability, and climate change affect domestic and global health. In this commentary we present a systematic review and categorization of the fiscal year (FY) 2008 NIH climate and health research portfolio. A list of candidate climate and health projects funded from FY 2008 budget appropriations were identified and characterized based on their relevance to climate change and health and based on climate pathway, health impact, study type, and objective. This analysis identified seven FY 2008 projects focused on climate change, 85 climate-related projects, and 706 projects that focused on disease areas associated with climate change but did not study those associations. Of the nearly 53,000 awards that NIH made in 2008, approximately 0.17% focused on or were related to climate. Given the nature and scale of the potential effects of climate change on human health and the degree of uncertainty that we have about these effects, we think that it is helpful for the NIH to engage in open discussions with science and policy communities about government-wide needs and opportunities in climate and health, and about how NIH's strengths in human health research can contribute to understanding the health implications of global climate change. This internal review has been used to inform more recent initiatives by the NIH in climate and health.

  11. A comparative study of the Indian summer monsoon hydroclimate and its variations in three reanalyses

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Vasubandhu [Florida State University, Department of Earth, Ocean and Atmospheric Science, Tallahassee, FL (United States); Florida State University, Center for Ocean-Atmospheric Prediction Studies, Tallahassee, FL (United States); Pantina, P. [Science Systems and Application, Inc., Lanham, MD (United States); NASA/GSFC, Cloud and Radiation Laboratory, Greenbelt, MD (United States); Chan, S.C. [Newcastle University, School of Civil Engineering and Geosciences, Newcastle upon Tyne (United Kingdom); Met Office Hadley Center, Exeter (United Kingdom); DiNapoli, S. [Florida State University, Center for Ocean-Atmospheric Prediction Studies, Tallahassee, FL (United States)

    2012-09-15

    This study examines the Indian summer monsoon hydroclimate in the National Centers for Environmental Prediction (NCEP)-Department of Energy (DOE) Reanalysis (R2), the Climate Forecast System Reanalysis (CFSR), and the Modern Era Retrospective-Analysis for Research and Applications (MERRA). The three reanalyses show significant differences in the climatology of evaporation, low-level winds, and precipitable water fields over India. For example, the continental evaporation is significantly less in CFSR compared to R2 and MERRA. Likewise the mean boreal summer 925 hPa westerly winds in the northern Indian Ocean are stronger in R2. Similarly the continental precipitable water in R2 is much less while it is higher and comparable in MERRA and CFSR. Despite these climatological differences between the reanalyses, the climatological evaporative sources for rain events over central India show some qualitative similarities. Major differences however appear when interannual variations of the Indian summer monsoon are analyzed. The anomalous oceanic sources of moisture from the adjacent Bay of Bengal and Arabian Sea play a significant role in determining the wet or dry year of the Indian monsoon in CFSR. However in R2 the local evaporative sources from the continental region play a more significant role. We also find that the interannual variability of the evaporative sources in the break spells of the intraseasonal variations of the Indian monsoon is stronger than in the wet spells. We therefore claim that instead of rainfall, evaporative sources may be a more appropriate metric to observe the relationship between the seasonal monsoon strength and intraseasonal activity. These findings are consistent across the reanalyses and provide a basis to improve the predictability of intraseasonal variability of the Indian monsoon. This study also has a bearing on improving weather prediction for tropical cyclones in that we suggest targeting enhanced observations in the Bay of Bengal

  12. Atmospheric Radiation Measurement Climate Research Facility (ACRF) Annual Report 2008

    Energy Technology Data Exchange (ETDEWEB)

    LR Roeder

    2008-12-01

    The Importance of Clouds and Radiation for Climate Change: The Earth’s surface temperature is determined by the balance between incoming solar radiation and thermal (or infrared) radiation emitted by the Earth back to space. Changes in atmospheric composition, including greenhouse gases, clouds, and aerosols, can alter this balance and produce significant climate change. Global climate models (GCMs) are the primary tool for quantifying future climate change; however, there remain significant uncertainties in the GCM treatment of clouds, aerosol, and their effects on the Earth’s energy balance. In 1989, the U.S. Department of Energy (DOE) Office of Science created the Atmospheric Radiation Measurement (ARM) Program to address scientific uncertainties related to global climate change, with a specific focus on the crucial role of clouds and their influence on the transfer of radiation in the atmosphere. To reduce these scientific uncertainties, the ARM Program uses a unique twopronged approach: • The ARM Climate Research Facility, a scientific user facility for obtaining long-term measurements of radiative fluxes, cloud and aerosol properties, and related atmospheric characteristics in diverse climate regimes; and • The ARM Science Program, focused on the analysis of ACRF and other data to address climate science issues associated with clouds, aerosols, and radiation, and to improve GCMs. This report provides an overview of each of these components and a sample of achievements for each in fiscal year (FY) 2008.

  13. Asian monsoon variability, cyclicities, and forcing mechanisms

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, P.D.

    meridonal over turning with the lower circulation limb being the strong low-level southwesterly summer monsoon winds of the western Indian Ocean. The convergence of these air masses and their uplift due to heating and orographic steering cause seasonal... is the dominant climatic feature of the Indian Ocean tropics and the adjacent continent. Boreal summer is characterized by high solar radiation that causes intense sensible and latent heating over northern India and Tibet Plateau. This pattern of heating...

  14. Variations of Indian monsoon precipitation during the last 32 kyr reflected in the surface hydrography of the Western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Govil, P.; Naidu, P.D.

    (Pierrehumbert, 2000). Furthermore, a decrease in Asian monsoon activity during stadials was related to less convective activity in the monsoon regions (Wang et al., 2001), which supports the concept that tropical convection and monsoon strength are related.... Climate Dynamics 12, 213–225. Pierrehumbert, R.T., 2000. Climate change and the tropical Pacific: The sleeping dragon wakes. Proceedings of National Academy of sciences 97, 1355-1358. Prell, W.L., 1984. Variation of monsoonal upwelling: a response...

  15. Assessment of cold-climate environmental research priorities

    Energy Technology Data Exchange (ETDEWEB)

    States, J.B.

    1983-04-01

    The Environmental Protection Agency (EPA) has consistently recognized that cold regions pose unique environmental problems. This report sets forth the conceptual framework and research plans for several high priority research areas. It provides the fundamental basis for implementation of the EPA Cold-Climate Environmental Research Program. This three- to five-year program encompasses both short- and long-term research of high relevance to the EPA and to the cold regions that it serves.

  16. Regional Climate Model Intercomparison Project for Asia.

    Science.gov (United States)

    Fu, Congbin; Wang, Shuyu; Xiong, Zhe; Gutowski, William J.; Lee, Dong-Kyou; McGregor, John L.; Sato, Yasuo; Kato, Hisashi; Kim, Jeong-Woo; Suh, Myoung-Seok

    2005-02-01

    Improving the simulation of regional climate change is one of the high-priority areas of climate study because regional information is needed for climate change impact assessments. Such information is especially important for the region covered by the East Asian monsoon where there is high variability in both space and time. To this end, the Regional Climate Model Intercomparison Project (RMIP) for Asia has been established to evaluate and improve regional climate model (RCM) simulations of the monsoon climate. RMIP operates under joint support of the Asia-Pacific Network for Global Change Research (APN), the Global Change System for Analysis, Research and Training (START), the Chinese Academy of Sciences, and several projects of participating nations. The project currently involves 10 research groups from Australia, China, Japan, South Korea, and the United States, as well as scientists from India, Italy, Mongolia, North Korea, and Russia.RMIP has three simulation phases: March 1997-August 1998, which covers a full annual cycle and extremes in monsoon behavior; January 1989-December 1998, which examines simulated climatology; and a regional climate change scenario, involving nesting with a global model. This paper is a brief report of RMIP goals, implementation design, and some initial results from the first phase studies.

  17. Research on Greenhouse-Gas-Induced Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, M. E.

    2001-07-15

    During the 5 years of NSF grant ATM 95-22681 (Research on Greenhouse-Gas-Induced Climate Change, $1,605,000, 9/15/1995 to 8/31/2000) we have performed work which we are described in this report under three topics: (1) Development and Application of Atmosphere, Ocean, Photochemical-Transport, and Coupled Models; (2) Analysis Methods and Estimation; and (3) Climate-Change Scenarios, Impacts and Policy.

  18. NASA indicators research in support of the National Climate Assessment

    Science.gov (United States)

    Leidner, A. K.; Houser, P. R.; Tsaoussi, L.

    2013-12-01

    Indicators have the potential to concisely communicate to a broad audience the observed and projected climate trends and anomalies, as well as society's vulnerability and ability to adapt to climate change. Consequently, indicators are anticipated to play an important role in the Fourth U.S. National Climate Assessment (NCA) report, slated to be released in four years. The NCA objectives include providing information about observed and anticipated changes in climate and assessing the impacts for regions and sectors, in order to help the nation prepare for a changing climate. Efforts are underway within the NCA to identify a set physical, ecological, and societal climate change indicators, by leveraging existing indicators currently in use by federal agencies. The NCA indicators are intended to provide meaningful and authoritative measures about the status and trends of climate for decision makers and the public. As a complement to this effort, and to support the NCA sustained assessment process, NASA solicited membership for an Indicators System Team and selected fourteen projects to begin research in summer 2013. These teams will develop and test potential new indicators that align with the vision set forth by the NCA, by combining NASA's remote sensing and modeling data products with additional datasets. Here, we further describe the objectives of the research program and highlight preliminary findings of several key projects related to physical, ecological, and societal climate change indicators, and discuss future research activities. Ultimately, this research will be made available in the peer-reviewed literature so that the newly developed indicators have the potential to be included in future NCA reports.

  19. Reconciling societal and scientific definitions for the monsoon

    Science.gov (United States)

    Reeve, Mathew; Stephenson, David

    2014-05-01

    Science defines the monsoon in numerous ways. We can apply these definitions to forecast data, reanalysis data, observations, GCMs and more. In a basic research setting, we hope that this work will advance science and our understanding of the monsoon system. In an applied research setting, we often hope that this work will benefit a specific stakeholder or community. We may want to inform a stakeholder when the monsoon starts, now and in the future. However, what happens if the stakeholders cannot relate to the information because their perceptions do not align with the monsoon definition we use in our analysis? We can resolve this either by teaching the stakeholders or learning from them about how they define the monsoon and when they perceive it to begin. In this work we reconcile different scientific monsoon definitions with the perceptions of agricultural communities in Bangladesh. We have developed a statistical technique that rates different scientific definitions against the people's perceptions of when the monsoon starts and ends. We construct a probability mass function (pmf) around each of the respondent's answers in a questionnaire survey. We can use this pmf to analyze the time series of monsoon onsets and withdrawals from the different scientific definitions. We can thereby quantitatively judge which definition may be most appropriate for a specific applied research setting.

  20. Increasing Diversity in Global Climate Change Research for Undergraduates

    Science.gov (United States)

    Johnson, L. P.; Marchese, P.; Carlson, B. E.; Howard, A. M.; Peteet, D. M.; Rosenzweig, C.; Druyan, L. M.; Fulakeza, M.; Gaffin, S.; Austin, S. A.; Cheung, T. D.; Damas, M. C.; Boxe, C.; Prince, T.; Ng, C.; Frost, J.

    2014-12-01

    Global Climate Change and the ability to predict the effects of forcings and feedback mechanisms on global and local climate are critical to the survival of the inhabitants of planet Earth. It is therefore important to motivate students to continue their studies towards advanced degrees and pursue careers related to climate change. This is best accomplished by involving undergraduates in global climate change research. This Research Experience for Undergraduates (REU) initiative is based at the City University of New York (CUNY) and the Goddard Institute for Space Studies (GISS), and is supported by NASA and NSF. Mentors for the primarily summer research experiences include CUNY faculty and GISS scientists. Research topics include the Wetland Carbon Project, The Cooling Power Of Urban Vegetation, Internal Ocean Mixing, El Niño Southern Oscillation, Pollution Transport and Tropospheric Ozone. Students are recruited from CUNY colleges and other colleges and universities. The program maintains an emphasis on under-represented minorities and females. Approximately sixty percent of the undergraduate students are under-represented minorities and forty percent are female. The project is supported by NSF award AGS-1359293 REU Site: CUNY/GISS Center for Global Climate Research.

  1. Natural and human-induced changes in summer climate over the East Asian monsoon region in the last half century: A review

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Ren-He

    2015-01-01

    In the last half century,a significant warming trend occurred in summer over eastern China in the East Asian monsoon region.However,there were no consistent trends with respect to the intensity of the East Asian summer monsoon(EASM) or the amount of summer rainfall averaged over eastern China.Both of the EASM and summer rainfall exhibited clear decadal variations.Obvious decadal shifts of EASM occurred around the mid- and late 1970 s,the late 1980 s and the early 1990 s,and the late 1990 s and early 2000 s,respectively.Summer rainfall over eastern China exhibited a change in spatial distribution in the decadal timescale,in response to the decadal shifts of EASM.From the mid- and late 1970 s to the late 1980 s and the early 1990 s,there was a meridional tri-polar rainfall distribution anomaly with more rainfall over the Yangtze River valley and less rainfall in North and South China; but in the period from the early 1990 s to the late 1990 s and the early 2000 s the tri-polar distribution changed to a dipolar one,with more rainfall appearing over southern China south to the Yangtze River valley and less rainfall in North China.However,from the early 2000 s to the late 2000 s,the Yangtze River valley received less rainfall.The decadal changes in EASM and summer rainfall over eastern China in the last half century are closely related to natural internal forcing factors such as Eurasian snow cover,Arctic sea ice,sea surface temperatures in tropical Pacific and Indian Ocean,oceaneatmospheric coupled systems of the Pacific Decadal Oscillation(PDO) and AsianePacific Oscillation(APO),and uneven thermal forcing over the Asian continent.Up to now,the roles of anthropogenic factors,such as greenhouse gases,aerosols,and land usage/cover changes,on existing decadal variations of EASM and summer rainfall in this region remain uncertain.

  2. Global surface temperature signals in pine ring-width chronologies from southern monsoon Asia

    Science.gov (United States)

    Buckley, B. M.; Cook, B. I.; Bhattacharyya, A.; Dukpa, D.; Chaudhary, V.

    2005-10-01

    We analyze Pinus ring width chronologies from three locations across monsoon Asia (Bhutan, India, and Thailand) where climate is dominated by the southwest monsoon in the boreal summer. We compare these records to global surface temperatures for the past 150 years, shifting the correlations through three seasonal averages: two seasons preceding the monsoon (Dec-Feb and Mar-May), and the monsoon season itself (Jun-Sep). Clear patterns emerge for each of the chronologies that highlight links to areas of known influence on the Asian monsoon: the Indian Ocean, the tropical eastern Pacific Ocean, and the high-latitude Asian landmass. The Thai and Indian chronologies are from the same species (P. merkusii), and show a strong correlation with tropical Indian and Pacific Ocean bands. The Bhutan chronology (P. Wallichiana) is most strongly linked to climate over the north Pacific and Asian landmass. All of these correlations are strongest in seasons preceding the summer monsoon.

  3. Effects of large-scale deforestation on precipitation in the monsoon regions: remote versus local effects.

    Science.gov (United States)

    Devaraju, N; Bala, Govindasamy; Modak, Angshuman

    2015-03-17

    In this paper, using idealized climate model simulations, we investigate the biogeophysical effects of large-scale deforestation on monsoon regions. We find that the remote forcing from large-scale deforestation in the northern middle and high latitudes shifts the Intertropical Convergence Zone southward. This results in a significant decrease in precipitation in the Northern Hemisphere monsoon regions (East Asia, North America, North Africa, and South Asia) and moderate precipitation increases in the Southern Hemisphere monsoon regions (South Africa, South America, and Australia). The magnitude of the monsoonal precipitation changes depends on the location of deforestation, with remote effects showing a larger influence than local effects. The South Asian Monsoon region is affected the most, with 18% decline in precipitation over India. Our results indicate that any comprehensive assessment of afforestation/reforestation as climate change mitigation strategies should carefully evaluate the remote effects on monsoonal precipitation alongside the large local impacts on temperatures.

  4. The contrasting features of Asian summer monsoon during surplus and deficient rainfall over India

    Science.gov (United States)

    Raju, P. V. S.; Mohanty, U. C.; Rao, P. L. S.; Bhatla, R.

    2002-12-01

    An endeavour is made to distinguish the mean summer monsoon features during surplus and deficient monsoon seasons. Based on all-India summer monsoon rainfall, over 42 years (1958-99), seven surplus and ten deficient monsoon seasons are identified. Making use of daily averaged (00 Z and 12 Z) reanalysis data sets from the National Center for Environmental Prediction-National Center for Atmospheric Research for the corresponding surplus and deficient monsoon seasons, the mean circulation characteristics and large-scale energetics are examined.The circulation features denote that the cross equatorial flow, low-level jet and tropical easterly jet are stronger during a surplus monsoon. Further, strong Tibetan anticyclonic flow characterizes a surplus monsoon. The large-scale balances of kinetic energy, heat and moisture show a significantly large quantity of diabatic heating, adiabatic generation of kinetic energy, and horizontal convergence of heat and moisture during the surplus monsoon season compared with the deficient state. The regions with statistically significant difference between surplus and deficient monsoon seasons are delineated by a Student's t-test at the 95% confidence level. The remarkable aspect noticed in this study is that the Arabian Sea branch of the monsoon circulation is more vigorous during a surplus monsoon season, whereas the eastern Bay of Bengal branch is stronger during a deficient monsoon. The various large-scale budget terms of kinetic energy, heat and moisture are found to be consistent and in agreement with the seasonal monsoon activity over India.

  5. Toward ethical norms and institutions for climate engineering research

    Science.gov (United States)

    Morrow, David R.; Kopp, Robert E.; Oppenheimer, Michael

    2009-10-01

    Climate engineering (CE), the intentional modification of the climate in order to reduce the effects of increasing greenhouse gas concentrations, is sometimes touted as a potential response to climate change. Increasing interest in the topic has led to proposals for empirical tests of hypothesized CE techniques, which raise serious ethical concerns. We propose three ethical guidelines for CE researchers, derived from the ethics literature on research with human and animal subjects, applicable in the event that CE research progresses beyond computer modeling. The Principle of Respect requires that the scientific community secure the global public's consent, voiced through their governmental representatives, before beginning any empirical research. The Principle of Beneficence and Justice requires that researchers strive for a favorable risk-benefit ratio and a fair distribution of risks and anticipated benefits, all while protecting the basic rights of affected individuals. Finally, the Minimization Principle requires that researchers minimize the extent and intensity of each experiment by ensuring that no experiments last longer, cover a greater geographical extent, or have a greater impact on the climate, ecosystem, or human welfare than is necessary to test the specific hypotheses in question. Field experiments that might affect humans or ecosystems in significant ways should not proceed until a full discussion of the ethics of CE research occurs and appropriate institutions for regulating such experiments are established.

  6. Toward ethical norms and institutions for climate engineering research

    Energy Technology Data Exchange (ETDEWEB)

    Morrow, David R [Department of Philosophy, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065 (United States); Kopp, Robert E; Oppenheimer, Michael, E-mail: morrow@uchicago.ed [Woodrow Wilson School of Public and International Affairs and Department of Geosciences, Princeton University, Princeton, NJ 08544 (United States)

    2009-10-15

    Climate engineering (CE), the intentional modification of the climate in order to reduce the effects of increasing greenhouse gas concentrations, is sometimes touted as a potential response to climate change. Increasing interest in the topic has led to proposals for empirical tests of hypothesized CE techniques, which raise serious ethical concerns. We propose three ethical guidelines for CE researchers, derived from the ethics literature on research with human and animal subjects, applicable in the event that CE research progresses beyond computer modeling. The Principle of Respect requires that the scientific community secure the global public's consent, voiced through their governmental representatives, before beginning any empirical research. The Principle of Beneficence and Justice requires that researchers strive for a favorable risk-benefit ratio and a fair distribution of risks and anticipated benefits, all while protecting the basic rights of affected individuals. Finally, the Minimization Principle requires that researchers minimize the extent and intensity of each experiment by ensuring that no experiments last longer, cover a greater geographical extent, or have a greater impact on the climate, ecosystem, or human welfare than is necessary to test the specific hypotheses in question. Field experiments that might affect humans or ecosystems in significant ways should not proceed until a full discussion of the ethics of CE research occurs and appropriate institutions for regulating such experiments are established.

  7. Meteorological fields variability over the Indian seas in pre and summer monsoon months during extreme monsoon seasons

    Indian Academy of Sciences (India)

    U C Mohanty; R Bhatla; P V S Raju; O P Madan; A Sarkar

    2002-09-01

    In this study, the possible linkage between summer monsoon rainfall over India and surface meteorological fields (basic fields and heat budget components) over monsoon region (30° E-120°E, 30°S-30°N) during the pre-monsoon month of May and summer monsoon season (June to September) are examined. For this purpose, monthly surface meteorological fields anomaly are analyzed for 42 years (1958-1999) using reanalysis data of NCEP/NCAR (National Center for Environmental Prediction/National Center for Atmospheric Research). The statistical significance of the anomaly (difference) between the surplus and deficient monsoon years in the surface meteorological fields are also examined by Student's t-test at 95% confidence level. Significant negative anomalies of mean sea level pressure are observed over India, Arabian Sea and Arabian Peninsular in the pre-monsoon month of May and monsoon season. Significant positive anomalies in the zonal and meridional wind (at 2m) in the month of May are observed in the west Arabian Sea off Somali coast and for monsoon season it is in the central Arabian Sea that extends up to Somalia. Significant positive anomalies of the surface temperature and air temperature (at 2m) in the month of May are observed over north India and adjoining Pakistan and Afghanistan region. During monsoon season this region is replaced by significant negative anomalies. In the month of May, significant positive anomalies of cloud amount are observed over Somali coast, north Bay of Bengal and adjoining West Bengal and Bangladesh. During monsoon season, cloud amount shows positive anomalies over NW India and north Arabian Sea. There is overall reduction in the incoming shortwave radiation flux during surplus monsoon years. A higher magnitude of latent heat flux is also found in surplus monsoon years for the month of May as well as the monsoon season. The significant positive anomaly of latent heat flux in May, observed over southwest Arabian Sea, may be considered

  8. Propagation and effects of monsoonal seasonally intense rainfall signal in river strata

    Science.gov (United States)

    Plink-Bjorklund, P.

    2014-12-01

    Climatic forcing signals in river systems tend to be modified on different temporal and spatial scales due to inherent signal buffering, re-routing, and a complex mixing of multiple autogenic and allogenic signals. Thus climate forcing response is generally assumed inherently non-linear with significant hysteresis effects. This paper explores propagation and effects of monsoonal, seasonally intense rainfall signal in river strata in the monsoonal and bordering subtropical domains. Some such rivers occur completely within the monsoon climate zone. Others have parts of their drainages in temperate climate zones, or on high elevations and receive some of their water discharge from other sources. Yet others, have their upstream drainages in the tropical monsoon climates, but flow through bordering subtropical drylands. Yet, all these rivers characteristically experience seasonal high magnitude floods as the effect of intense monsoon precipitation. Many rivers in the bordering subtropical zone receive monsoon rain and transmit discharge only during abnormal or strengthened monsoon seasons and associated cyclonic flow. Field datasets, comparison to modern river deposits and a literature review of monsoonal and bordering subtropical domain rivers reveal that the effects of the intense seasonal monsoon rain and the resultant flooding are readily recognizable in modern and ancient fluvial strata. This paper argues that this distinct and dominant climate signal propagation occurs because it is the monsoon discharge that is commonly responsible for up to 100% of sediment erosion, transport and deposition, creating a system wide flushing or splash effect on a single season to multi-million year time scale. The distinct monsoon flood deposits are interbedded with other types of fluvial strata in systems where significant deposition also occurs from low-magnitude flood or non-flood discharges.

  9. Bridging the Gap between Climate Research and Policy

    Science.gov (United States)

    Weiss, M.; Lambert, K. F.; Buonocore, J.; Driscoll, C. T.

    2016-12-01

    The weak link between science and policy jeopardizes the wellbeing of people and the planet. Climate change is a pressing example of this disconnect. Policies are not keeping pace with the best of our knowledge from climate change research. We are working to bridge the science-policy divide and advance climate solutions by focusing on the positive health, ecosystem, and economic benefits of policy action. In 2013, we brought together an interdisciplinary team to estimate the co-benefits of U.S. power plant carbon standards for air quality and health, plus the economic value of the benefits. The results demonstrate that strong carbon standards with flexible compliance options can change the power sector, yielding substantial air quality and health benefits nationwide. The results also show that the economic value of these benefits outweighs the costs nationally and regionally. We advanced the policy applications of this research through a strategic campaign with three key elements: media communication, targeted outreach, and information for policymakers. Our strategy was to build widespread awareness of the research outcomes via media engagement, amplify our message via targeted outreach to citizens groups, and inform policy solutions by sharing research results with decision makers. The research was reported in more than 600 unique news stories in mainstream media outlets and received social media posts by members of Congress and senior White House officials. We amplified the messages via 14 webinars for citizens groups. We also held 16 briefings for policymakers and the public, in addition to meetings with relevant policy staff. Regional, state and federal policy leaders have used the research to understand air quality and health benefits of power plant carbon standards. This model of pairing research with media communication, targeted outreach, and information for policymakers is effective for bridging the gap between climate research and policy, and can be

  10. Variabilidade do regime de monções sobre o Brasil: o clima presente e projeções para um cenário com 2xCO2 usando o modelo MIROC Variability of the monsoon regime over Brazil: the present climate and projections for a 2xCO2 scenario using the MIROC model

    Directory of Open Access Journals (Sweden)

    Rodrigo José Bombardi

    2008-03-01

    Full Text Available Este trabalho investiga a variabilidade do Sistema de Monções da América do Sul (SMAS sobre o Brasil com particular interesse na região do cerrado brasileiro. O início, final e total de precipitação durante as monções de verão são examinados utilizando estimativas de precipitação por satélite (pêntadas do Global Precipitation Climatology Project (GPCP entre 1979-2004. Analogamente, as características do regime de monção simuladas pelo modelo climático global acoplado MIROC (Model for interdisciplinary Research on Climate do IPCC (Intergovernmental Panel for Climate Change são examinadas em dois cenários distintos: o clima do século XX (1981-2000 e o clima em uma condição com o dobro da concentração atual de CO2 (2xCO2 na atmosfera (2061-2080. Mostra-se que a variabilidade espacial do início da monção de verão sobre o cerrado na simulação do clima do século XX pelo MIROC corresponde bem às observações. Além disso, há indicação de uma mudança das caudas da distribuição sazonal da precipitação no Cerrado para um cenário com 2xCO2, comparativamente com o clima presente. Este resultado sugere uma mudança na probabilidade de ocorrência de eventos extremos (secos ou úmidos em um cenário com 2xCO2 sobre o cerrado, o que de acordo com o MIROC, indica uma maior exposição da região às conseqüências de possíveis mudanças climáticas resultantes do aumento de gases de efeito estufa.This study investigates the temporal variability of the South America monsoon system (SAMS over Brazil with focus on the Brazilian savanna. The onset, end, and total rainfall during the summer monsoon are investigated using precipitation pentad estimates from the Global Precipitation Climatology Project (1979-2004. Likewise, the variability of SAMS characteristics are investigated using the intergovernmental Panel for Climate Change (IPCC coupled global climate model for Interdisciplinary Research (MIROC in the 20th century

  11. Instrumental evidence of an unusually strong West African Monsoon in the 19th century

    Science.gov (United States)

    Gallego, David; Ordoñez, Paulina; Ribera, Pedro; Peña-Ortiz, Cristina; Garcia-Herrera, Ricardo; Vega, Inmaculada; Gomez, Francisco de Paula

    2016-04-01

    The precipitation in the Sahel -which is mainly controlled by the dynamics of the West African Monsoon-, has been in the spot of the climate community for the last three decades due to the persistence of the drought period that started in the 1970s. Unfortunately, reliable meteorological series in this area are only available since the beginning of the 20th Century, thus limiting our understanding of the significance of this period from a long term perspective. Currently, our knowledge of what happened in times previous to the 20th Century essentially relies in documentary or proxy sources. In this work, we present the first instrumental evidence of a 50 year-long period characterised by an unusually strong West African monsoon in the19th Century. Following the recent advances in the generation of climatic indices based on data from ship's logbooks, we used historical wind observations to compute a new index (the so-called ASWI) for characterising the strength of the West African Monsoon. The ASWI is based in the persistence of the southwesterly winds in the [29°W-17°W;7°N-13°N] area and it has been possible to compute it since 1790 for July and since 1839 for August and September. We show that the ASWI is a reliable measure of the monsoon's strength and the Sahelian rainfall. Our new series clearly shows the well-known drought period starting in the 1970s. During this dry period, the West African Monsoon was particularly weak and interestingly, we found that since then, the correlations with different climatic patterns such as the Pacific and Atlantic "El Niño" changed significantly in relation to those of the previous century. Remarkably, our results also show that the period 1839-1890 was characterised by an unusually strong and persistent monsoon. Notwithstanding, two of the few dry years within this period were concurrent with large volcanic eruptions in the Northern Hemisphere. This latter result supports the recently suggested relationship between major

  12. Reconciling justice and attribution research to advance climate policy

    Science.gov (United States)

    Huggel, Christian; Wallimann-Helmer, Ivo; Stone, Dáithí; Cramer, Wolfgang

    2016-10-01

    The Paris Climate Agreement is an important step for international climate policy, but the compensation for negative effects of climate change based on clear assignment of responsibilities remains highly debated. From both a policy and a science perspective, it is unclear how responsibilities should be defined and on what evidence base. We explore different normative principles of justice relevant to climate change impacts, and ask how different forms of causal evidence of impacts drawn from detection and attribution research could inform policy approaches in accordance with justice considerations. We reveal a procedural injustice based on the imbalance of observations and knowledge of impacts between developed and developing countries. This type of injustice needs to be considered in policy negotiations and decisions, and efforts strengthened to reduce it.

  13. Forcing mechanism of the Pleistocene east Asian monsoon variations in a phase perspective

    Institute of Scientific and Technical Information of China (English)

    TIAN; Jun; WANG; Pinxian; CHENG; Xinrong; WANG; Rujian; SU

    2005-01-01

    The deep sea records from the ODP Sites 1143 and 1144 in the northern and southern South China Sea (SCS), including foraminiferal δ18O and δ13C, Opal% and pollen percentage, reveal that the variations of the east Asian monsoon have been closely correlated with the variations of the Earth's orbital parameters (eccentricity, obliquity and precession) and the global ice volume on orbital scale. All the monsoonal proxies show strong 100 ka, 41 ka and 23 ka cycles. Although G. ruber δ13C of Site 1143 is coherent with the ETP (ETP= normalized (eccentricity + obliquity-precession) at eccentricity, obliquity and precession bands, most of the coherent relationship focuses on the precession band, and the other monsoonal proxies are coherent with the ETP only at the precession band, which indicate that precession dominates the Pleistocene tropical climate changes. The phase relationship of the monsoonal proxies with the foraminiferal δ18O implies that the global ice volume changes have played a significant role in modulating the east Asian monsoon climate, at least dominating the winter monsoon. This forcing mechanism of the east Asian monsoon is apparently different from that of the Indian ocean monsoon. The variations of the east Asian monsoon at the precession band, at least that of the winter monsoon, have been controlled not only by the sensible heating but also by the latent heating of the surface water in the South China Sea.

  14. Climate research and climate negotiations - status and prospect; Klimaforskning og klimaforhandlinger - status og utsikter fremover

    Energy Technology Data Exchange (ETDEWEB)

    Torvanger, Asbjoern; Fuglestvedt, Jan; Holtsmark, Bjart; Naess, Lars Otto

    1997-12-31

    This report describes the climate process from the preliminary work on the Climate Convention to the negotiations about the Berlin mandate about the increased commitments of the industrialised countries to reduce their emissions of greenhouse gases. Future prospects are discussed up to the Kyoto meeting in 1997. A status survey is given of the climate research and possible man-made climate disturbances. The various countries take different positions on some of the most important issues in the negotiations: (1) Are the various countries to have the same goal, or should the goals be differentiated?, (2) Goal and dating of emission reductions, (3) Selection of measures and means, (4) Flexibility in the fulfillment of commitments over time, (5) Only carbon dioxide or more greenhouse gases?, (6) Is binding of carbon dioxide through net forest growth to be included in the negotiations? 32 refs., 52 figs.

  15. An East Asian Monsoon in the Mid-Pliocene

    Institute of Scientific and Technical Information of China (English)

    YAN Qing; ZHANG Zhong-Shi; GAO Yong-Qi

    2012-01-01

    In this study, the authors simulate the East Asian climate changes in the mid-Pliocene (~3.3 to 3.0 Ma BP) with the Community Atmosphere Model version 3.1 (CAM3.1) and compare the simulated East Asian monsoon with paleoclimate data. The simulations show an obvious warming pattern in East Asia in the mid-Pliocene compared with the pre-industrial climate, with surface air temperature increasing by 0.5 4.0°C. In the warm mid-Pliocene simulation, the East Asian Summer Monsoon (EASM) becomes stronger, while the East Asian Winter Monsoon (EAWM) is similar relative to the pre-industrial climate. Compared with the paleoclimate data, our simulations depict the intensified EASM well but cannot reproduce the weakened EAWM. This model-data discrepancy may be attributed to the uncertainty in the reconstructed mid-Pliocene sea surface temperature.

  16. Earth observation big data for climate change research

    Institute of Scientific and Technical Information of China (English)

    GUO; Hua-Dong; ZHANG; Li; ZHU; Lan-Wei

    2015-01-01

    Earth observation technology has provided highly useful information in global climate change research over the past few decades and greatly promoted its development,especially through providing biological,physical,and chemical parameters on a global scale.Earth observation data has the 4V features(volume,variety,veracity,and velocity) of big data that are suitable for climate change research.Moreover,the large amount of data available from scientific satellites plays an important role.This study reviews the advances of climate change studies based on Earth observation big data and provides examples of case studies that utilize Earth observation big data in climate change research,such as synchronous satelliteeaerialeground observation experiments,which provide extremely large and abundant datasets; Earth observational sensitive factors(e.g.,glaciers,lakes,vegetation,radiation,and urbanization); and global environmental change information and simulation systems.With the era of global environment change dawning,Earth observation big data will underpin the Future Earth program with a huge volume of various types of data and will play an important role in academia and decisionmaking.Inevitably,Earth observation big data will encounter opportunities and challenges brought about by global climate change.

  17. Collaborative Research for Water Resource Management under Climate Change Conditions

    Science.gov (United States)

    Brundiers, K.; Garfin, G. M.; Gober, P.; Basile, G.; Bark, R. H.

    2010-12-01

    We present an ongoing project to co-produce science and policy called Collaborative Planning for Climate Change: An Integrated Approach to Water-Planning, Climate Downscaling, and Robust Decision-Making. The project responds to motivations related to dealing with sustainability challenges in research and practice: (a) state and municipal water managers seek research that addresses their planning needs; (b) the scientific literature and funding agencies call for more meaningful engagement between science and policy communities, in ways that address user needs, while advancing basic research; and (c) empirical research contributes to methods for the design and implementation of collaborative projects. To understand how climate change might impact water resources and management in the Southwest US, our project convenes local, state, and federal water management practitioners with climate-, hydrology-, policy-, and decision scientists. Three areas of research inform this collaboration: (a) the role of paleo-hydrology in water resources scenario construction; (b) the types of uncertainties that impact decision-making beyond climate and modeling uncertainty; and (c) basin-scale statistical and dynamical downscaling of climate models to generate hydrologic projections for regional water resources planning. The project engages all participants in the research process, from research design to workshops that build capacity for understanding data generation and sources of uncertainty to the discussion of water management decision contexts. A team of “science-practice translators” facilitates the collaboration between academic and professional communities. In this presentation we contextualize the challenges and opportunities of use-inspired science-policy research collaborations by contrasting the initial project design with the process of implementation. We draw from two sources to derive lessons learned: literature on collaborative research, and evaluations provided by

  18. Lidar profiling of aerosols and clouds for regional climate and pollution research

    Science.gov (United States)

    Devara, Panuganti C. S.; Raj, Pulidindi E.; Pandithurai, G.; Dani, Kundan K.; Saha, Sanjoy K.; Sonbawne, Sunil M.

    2006-12-01

    The space-time variability of aerosol inhomogeneities provides unique information on atmospheric behavior needed for climate and environmental research and operational programs. An additional indirect forcing from aerosols results from their involvement in nucleation and growth of cloud droplets, reducing droplet size and thereby potentially influencing cloud albedo. These studies have particular significance over tropics where the convective and dynamical processes associated with high-altitude thunderstorms greatly affect the vertical distributions of aerosols and pre-cursor gases. As the anthropogenic share of the total aerosol loading is quite substantial over many parts of the world, it is essential to monitor the aerosol features systematically over longer time scales. Such observations are very important for understanding the coupling processes that exist between physico-chemical, radiative, dynamical and biological phenomena in the Earth's environment, and provide valuable input information for modeling and simulation studies of climate and air quality. The multi-year aerosol number density data acquired during October 1986-September 2000 with a computer-controlled lidar at the Indian Institute of Tropical Meteorology (IITM), Pune, an urban station in India have been utilized to investigate (i) climate variability, (ii) cloud macro-physical parameters and (iii) environmental pollution. The results reveal a long-term trend in aerosol loading, single and multiple layer clouds with low cloud-base during the south-west monsoon months, and high pollution potential during winter late evenings. The trends in aerosol loading and air quality are found to be changing from year to year depending upon meteorological parameters (precipitation in particular). Some of these parameters have also been compared with co-located complementary facilities such as solar radiometers. In order to enlarge the scope of these studies, a dual polarization micro pulse lidar (DPMPL) has

  19. Transient coupling relationships of the Holocene Australian monsoon

    CERN Document Server

    McRobie, Fiona H; Wyrwoll, Karl-Heinz

    2015-01-01

    The modern-day northwest Australian summer monsoon is dynamically coupled to other regional monsoon systems and inflows from the Indian Ocean, however, the nature of these relationships over longer time scales is uncertain. Previous attempts to evaluate how proxy records from the Indonesian-Australian monsoon region correspond to other records from the Indian and East Asian monsoon regions, as well as to El Ni\\~no-related proxy records, has been qualitative, relying on `curve-fitting' methods. Here, we seek a quantitative approach for identifying coupling relationships between paleoclimate proxy records, employing statistical techniques to compute the interdependence of two paleoclimate time series. We verify the use of complex networks to identify coupling relationships between modern climate indices which correspond to physically-based mechanisms. This method is then extended to a set of paleoclimate proxy records from the Asian, Australasian and South American regions spanning the past 9,000 years. The res...

  20. Holocene vegetation variation in the Daihai Lake region of north-central China: a direct indication of the Asian monsoon climatic history

    Science.gov (United States)

    Xiao, Jule; Xu, Qinghai; Nakamura, Toshio; Yang, Xiaolan; Liang, Wendong; Inouchi, Yoshio

    2004-07-01

    DH99a sediment core recovered at the center of Daihai Lake in north-central China was analyzed at 4-cm intervals for pollen assemblage and concentration. The pollen record spanning the last ca 10,000 yr revealed a detailed history of vegetation and climate changes over the Daihai Lake region during the Holocene. From ca 10,250 to 7900 cal yr BP, arid herbs and shrubs dominated the lake basin in company with patches of mixed pine and broadleaved forests, indicating a mild and dry climatic condition. Over this period, the woody plants displayed an increasing trend, which may suggest a gradual increase in warmth and humidity. The period between ca 7900 and 4450 cal yr BP exhibits large-scale covers of mixed coniferous and broadleaved forests, marking a warm and humid climate. Changes in the composition of the forests indicate that both temperature and precipitation displayed obvious fluctuations during this period, i.e., cool and humid ca 7900- 7250 cal yr BP, warm and slightly humid ca 7250- 6050 cal yr BP, warm and humid between ca 6050 and 5100 cal yr BP, mild and slightly humid ca 5100- 4800 cal yr BP, and mild and humid ca 4800- 4450 cal yr BP. The period can be viewed as the Holocene optimum (characterized by a warm and moist climate) of north-central China, with the maximum (dominated both by warmest temperatures and by richest precipitations) occurring from ca 6050 to 5100 cal yr BP. During the period of ca 4450- 2900 cal yr BP, the woody plants declined, and the climate generally became cooler and drier than the preceding period. This period is characterized by a cold, dry episode from ca 4450 to 3950 cal yr BP, a warm, slightly humid interval between ca 3950 and 3500 cal yr BP and a mild, slightly dry episode from ca 3500 to 2900 cal yr BP, and appears to be a transition from warm and humid to cold and dry climatic conditions. Since ca 2900 cal yr ago, the forests disappeared and the vegetation density decreased, reflecting a cool and dry climate. However, a

  1. Climate services in the tourism sector - examples and market research

    Science.gov (United States)

    Damm, Andrea; Köberl, Judith; Prettenthaler, Franz; Kortschak, Dominik; Hofer, Marianne; Winkler, Claudia

    2017-04-01

    Tourism is one of the most weather-sensitive sectors. Hence, dealing with weather and climate risks is an important part of operational risk management. WEDDA® (WEather Driven Demand Analysis), developed by Joanneum Research, represents a comprehensive and flexible toolbox for managing weather and climate risks. Modelling the demand for products or services of a particular economic sector or company and its weather and climate sensitivity usually forms the starting and central point of WEDDA®. Coupling the calibrated demand models to either long-term climate scenarios or short-term weather forecasts enables the use of WEDDA® for the following areas of application: (i) implementing short-term forecasting systems for the prediction of the considered indicator; (ii) quantifying the weather risk of a particular economic sector or company using parameters from finance (e.g. Value-at-Risk); (iii) assessing the potential impacts of changing climatic conditions on a particular economic sector or company. WEDDA® for short-term forecasts on the demand for products or services is currently used by various tourism businesses, such as open-air swimming pools, ski areas, and restaurants. It supports tourism and recreation facilities to better cope with (increasing) weather variability by optimizing the disposability of staff, resources and merchandise according to expected demand. Since coping with increasing weather variability forms one of the challenges with respect to climate change, WEDDA® may become an important component within a whole pool of weather and climate services designed to support tourism and recreation facilities to adapt to climate change. Climate change impact assessments at European scale, as conducted in the EU-FP7 project IMPACT2C, provide basic information of climate change impacts on tourism demand not only for individual tourism businesses, but also for regional and national tourism planners and policy makers interested in benchmarks for the

  2. Aviation Climate Change Research Initiative (ACCRI) - An Update

    Science.gov (United States)

    Gupta, M. L.

    2009-12-01

    Aviation plays an important role in global and domestic economic development and transport mobility. There are environmental concerns associated with aviation noise and emissions. Aircraft climate impacts are primarily due to release of emissions at the cruise altitude in the upper troposphere and lower stratosphere. Even though small in magnitude at present, aviation climate impacts will likely increase with projected growth in air transport demand unless scientifically informed and balanced mitigation solutions are implemented in a timely manner. There are large uncertainties associated with global and regional non-CO2 aviation climate impacts which need to be well quantified and constrained to support decision making. To meet future aviation capacity needs, the United States is developing and implementing a dynamic, flexible and scalable Next Generation Air Transportation System (NextGen) that is safe, secure, efficient and environmentally sound. One of the stated NextGen environmental goals is to limit or reduce the impacts of aviation emissions on global climate. With the support from the participating agencies of the U.S. Climate Change Science Program, the Federal Aviation Administration (FAA) has developed Aviation Climate Change Research Initiative (ACCRI) with the main objective to identify and address key scientific gaps and uncertainties that are most likely to be achieved in near (up to 18 months) and mid (up to 36 months) term horizons while providing timely scientific input to inform decision making. Till date, ACCRI funded activities have resulted in release of 8 subject-specific whitepapers and a report on The Way Forward. These documents can be accessed via http://www.faa.gov/about/office_org/headquarters_offices/aep/aviation_climate/media/ACCRI_Report_final.pdf. This presentation will provide details on prioritized key scientific gaps and uncertainties to better characterize aviation climate impacts. This presentation will also include a brief

  3. Recent change of the global monsoon precipitation (1979-2008)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bin [University of Hawaii at Manoa, Department of Meteorology, Honolulu, HI (United States); University of Hawaii at Manoa, International Pacific Research Center, Honolulu, HI (United States); Liu, Jian [Chinese Academy of Sciences, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Nanjing (China); Kim, Hyung-Jin [Japan Agency for Marine-Earth Science and Technology, Research Institute for Global Change, Yokohama, Kanagawa (Japan); Webster, Peter J. [Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA (United States); Yim, So-Young [University of Hawaii at Manoa, International Pacific Research Center, Honolulu, HI (United States)

    2012-09-15

    The global monsoon (GM) is a defining feature of the annual variation of Earth's climate system. Quantifying and understanding the present-day monsoon precipitation change are crucial for prediction of its future and reflection of its past. Here we show that regional monsoons are coordinated not only by external solar forcing but also by internal feedback processes such as El Nino-Southern Oscillation (ENSO). From one monsoon year (May to the next April) to the next, most continental monsoon regions, separated by vast areas of arid trade winds and deserts, vary in a cohesive manner driven by ENSO. The ENSO has tighter regulation on the northern hemisphere summer monsoon (NHSM) than on the southern hemisphere summer monsoon (SHSM). More notably, the GM precipitation (GMP) has intensified over the past three decades mainly due to the significant upward trend in NHSM. The intensification of the GMP originates primarily from an enhanced east-west thermal contrast in the Pacific Ocean, which is coupled with a rising pressure in the subtropical eastern Pacific and decreasing pressure over the Indo-Pacific warm pool. While this mechanism tends to amplify both the NHSM and SHSM, the stronger (weaker) warming trend in the NH (SH) creates a hemispheric thermal contrast, which favors intensification of the NHSM but weakens the SHSM. The enhanced Pacific zonal thermal contrast is largely a result of natural variability, whilst the enhanced hemispherical thermal contrast is likely due to anthropogenic forcing. We found that the enhanced global summer monsoon not only amplifies the annual cycle of tropical climate but also promotes directly a ''wet-gets-wetter'' trend pattern and indirectly a ''dry-gets-drier'' trend pattern through coupling with deserts and trade winds. The mechanisms recognized in this study suggest a way forward for understanding past and future changes of the GM in terms of its driven mechanisms. (orig.)

  4. ARM Climate Research Facility Monthly Instrument Report September 2010

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, JW

    2010-10-18

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.

  5. ARM Climate Research Facility Monthly Instrument Report August 2010

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, JW

    2010-09-28

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.

  6. ARM Climate Research Facility Instrumentation Status and Information February 2010

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, JW

    2010-03-25

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.

  7. ARM Climate Research Facility Monthly Instrument Report June 2010

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, JW

    2010-07-13

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.

  8. ARM Climate Research Facility Instrumentation Status and Information December 2009

    Energy Technology Data Exchange (ETDEWEB)

    JW Voyles

    2010-12-30

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.

  9. ARM Climate Research Facility Instrumentation Status and Information October 2009

    Energy Technology Data Exchange (ETDEWEB)

    JW Voyles

    2009-10-01

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.

  10. ARM Climate Research Facility Monthly Instrument Report May 2010

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, JW

    2010-06-21

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.

  11. ARM Climate Research Facility Instrumentation Status and Information April 2010

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, JW

    2010-05-15

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.

  12. ARM Climate Research Facility Instrumentation Status and Information March 2010

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, JW

    2010-04-19

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.

  13. ARM Climate Research Facility Instrumentation Status and Information January 2010

    Energy Technology Data Exchange (ETDEWEB)

    JW Voyles

    2010-02-28

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.

  14. ARM Climate Research Facility Monthly Instrument Report July 2010

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, JW

    2010-08-18

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.

  15. Forecasting Monsoon Precipitation Using Artificial Neural Networks

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper explores the application of Artificial Intelligent (AI) techniques for climate forecast. It pres ents a study on modelling the monsoon precipitation forecast by means of Artificial Neural Networks (ANNs). Using the historical data of the total amount of summer rainfall over the Delta Area of Yangtze River in China, three ANNs models have been developed to forecast the monsoon precipitation in the corre sponding area one year, five-year, and ten-year forward respectively. Performances of the models have been validated using a 'new' data set that has not been exposed to the models during the processes of model development and test. The experiment results are promising, indicating that the proposed ANNs models have good quality in terms of the accuracy, stability and generalisation ability.

  16. Preliminary Estimation of Black Carbon Deposition from Nepal Climate Observatory-Pyramid Data and Its Possible Impact on Snow Albedo Changes Over Himalayan Glaciers During the Pre-Monsoon Season

    Science.gov (United States)

    Yasunari, T. J.; Bonasoni, P.; Laj, P.; Fujita, K.; Vuillermoz, E.; Marinoni, A.; Cristofanelli, P.; Duchi, R.; Tartari, G.; Lau, K.-M.

    2010-01-01

    The possible minimal range of reduction in snow surface albedo due to dry deposition of black carbon (BC) in the pre-monsoon period (March-May) was estimated as a lower bound together with the estimation of its accuracy, based on atmospheric observations at the Nepal Climate Observatory-Pyramid (NCO-P) sited at 5079 m a.s.l. in the Himalayan region. We estimated a total BC deposition rate of 2.89 g m-2 day-1 providing a total deposition of 266 micrograms/ square m for March-May at the site, based on a calculation with a minimal deposition velocity of 1.0 10(exp -4) m/s with atmospheric data of equivalent BC concentration. Main BC size at NCO-P site was determined as 103.1-669.8 nm by correlation analysis between equivalent BC concentration and particulate size distribution in the atmosphere. We also estimated BC deposition from the size distribution data and found that 8.7% of the estimated dry deposition corresponds to the estimated BC deposition from equivalent BC concentration data. If all the BC is deposited uniformly on the top 2-cm pure snow, the corresponding BC concentration is 26.0-68.2 microgram/kg assuming snow density variations of 195-512 kg/ cubic m of Yala Glacier close to NCO-P site. Such a concentration of BC in snow could result in 2.0-5.2% albedo reductions. From a simple numerical calculations and if assuming these albedo reductions continue throughout the year, this would lead to a runoff increases of 70-204 mm of water drainage equivalent of 11.6-33.9% of the annual discharge of a typical Tibetan glacier. Our estimates of BC concentration in snow surface for pre-monsoon season can be considered comparable to those at similar altitude in the Himalayan region, where glaciers and perpetual snow region starts in the vicinity of NCO-P. Our estimates from only BC are likely to represent a lower bound for snow albedo reductions, since a fixed slower deposition velocity was used and atmospheric wind and turbulence effects, snow aging, dust deposition

  17. Engaging Scientists and Users in Climate Change Research and Results

    Science.gov (United States)

    Cloyd, E. T.; Reeves, K.; Shimamoto, M. M.; Zerbonne, S.

    2016-12-01

    The U.S. Global Change Research Program has a mandate to "consult with actual and potential users of the results of the program" in developing products that will support learning about and responding to climate change. USGCRP has sought to engage stakeholders throughout the development and dissemination of key products, such as the Third National Climate Assessment (NCA3, 2014) and the Climate and Health Assessment (CHA, 2016), in the strategic planning processes leading to the National Global Change Research Plan (2012) and Update to the Strategic Plan (2016), and through regular postings to social media that highlight research results and opportunities for engagement. Overall, USGCRP seeks to promote dialogue between scientific experts, stakeholders, and decision makers about information needs in regions or sectors, the potential impacts of climate change, and possible responses. This presentation will describe how USGCRP has implemented various stakeholder engagement measures during the planning, development, and release of products such as NCA3 and CHA. Through repeated opportunities for stakeholder input, USGCRP has promoted process transparency and inclusiveness in the framing of assessments and other products. In addition, USGCRP has supported scientists' engagement with a range of audiences and potential collaborators through a variety of mechanisms, including community-based meetings, deliberative forums, and identification of non-Federal speaking and knowledge co-production opportunities. We will discuss key lessons learned and successful approaches for engaging users as well as opportunities and challenges for future engagement.

  18. Experience of the Paris Research Consortium Climate-Environment-Society

    Science.gov (United States)

    Joussaume, Sylvie; Pacteau, Chantal; Vanderlinden, Jean Paul

    2016-04-01

    It is now widely recognized that the complexity of climate change issues translates itself into a need for interdisciplinary approaches to science. This allows to first achieve a more comprehensive vision of climate change and, second, to better inform the decision-making processes. However, it seems that willingness alone is rarely enough to implement interdisciplinarity. The purpose of this presentation is to mobilize reflexivity to revisit and analyze the experience of the Paris Consortium for Climate-Environment-Society. The French Consortium Climate-Environment-Society aims to develop, fund and coordinate interdisciplinary research into climate change and its impacts on society and environment. Launched in 2007, the consortium relies on the research expertise of 17 laboratories and federation in the Paris area working mainly in the fields of climatology, hydrology, ecology, health sciences, and the humanities and social sciences. As examples, economists and climatologists have studied greenhouse gas emission scenarios compatible with climate stabilization goals. Historical records have provided both knowledge about past climate change and vulnerability of societies. Some regions, as the Mediterranean and the Sahel, are particularly vulnerable and already have to cope with water availability, agricultural production and even health issues. A project showed that millet production in West Africa is expected to decline due to warming in a higher proportion than observed in recent decades. Climate change also raises many questions concerning health: combined effects of warming and air quality, impacts on the production of pollens and allergies, impacts on infectious diseases. All these issues lead to a need for approaches integrating different disciplines. Furthermore, climate change impacts many ecosystems which, in turn, affect its evolution. Our experience shows that interdisciplinarity supposes, in order to take shape, the conjunction between programming

  19. Soil moisture variations in remotely sensed and reanalysis datasets during weak monsoon conditions over central India and central Myanmar

    Science.gov (United States)

    Shrivastava, Sourabh; Kar, Sarat C.; Sharma, Anu Rani

    2017-07-01

    Variation of soil moisture during active and weak phases of summer monsoon JJAS (June, July, August, and September) is very important for sustenance of the crop and subsequent crop yield. As in situ observations of soil moisture are few or not available, researchers use data derived from remote sensing satellites or global reanalysis. This study documents the intercomparison of soil moisture from remotely sensed and reanalyses during dry spells within monsoon seasons in central India and central Myanmar. Soil moisture data from the European Space Agency (ESA)—Climate Change Initiative (CCI) has been treated as observed data and was compared against soil moisture data from the ECMWF reanalysis-Interim (ERA-I) and the climate forecast system reanalysis (CFSR) for the period of 2002-2011. The ESA soil moisture correlates rather well with observed gridded rainfall. The ESA data indicates that soil moisture increases over India from west to east and from north to south during monsoon season. The ERA-I overestimates the soil moisture over India, while the CFSR soil moisture agrees well with the remotely sensed observation (ESA). Over Myanmar, both the reanalysis overestimate soil moisture values and the ERA-I soil moisture does not show much variability from year to year. Day-to-day variations of soil moisture in central India and central Myanmar during weak monsoon conditions indicate that, because of the rainfall deficiency, the observed (ESA) and the CFSR soil moisture values are reduced up to 0.1 m3/m3 compared to climatological values of more than 0.35 m3/m3. This reduction is not seen in the ERA-I data. Therefore, soil moisture from the CFSR is closer to the ESA observed soil moisture than that from the ERA-I during weak phases of monsoon in the study region.

  20. Upper tropospheric CH4 and CO affected by the Indian summer monsoon during OMO

    Science.gov (United States)

    Tomsche, Laura; Pozzer, Andrea; Zimmermann, Peter; Parchatka, Uwe; Lelieveld, Jos; Fischer, Horst

    2017-04-01

    The trace gas transport through the Indian summer monsoon convection was investigated as part of the aircraft campaign OMO (Oxidation Mechanism Observations) using the German research aircraft HALO (High Altitude and Long Range Research Aircraft) in July/August 2015. HALO was operated alternatively from Cyprus and the Maldives. Flights took place over the Mediterranean Sea, the Arabian Peninsula and the Arabian Sea. Here we investigate the distribution of carbon monoxide (CO) and methane (CH4) in the upper troposphere, measured in-situ with the IR-laser absorption spectrometer TRISTAR. During OMO enhanced concentrations of CH4 and CO were detected in the Asian Summer monsoon anticyclone at altitudes between 11 km and 15 km. Mixing ratios exceeded background levels for CO and CH4 by 10-15 ppb and 30-40 ppb, respectively. The enhancement in the CO concentration appears to be within the range of tropospheric variability, while the methane enhancement is much higher than its natural variability. Therefore CH4 is found to be a very good tracer for air masses influenced by the monsoon. This is confirmed by back trajectory calculations with FLEXPART, indicating convective transport from India approximately 10 days before the observations. A comparison of observations with EMAC atmospheric chemistry - climate model simulations generally agree within ± 10% and ± 0.5% for CO and CH4, respectively.

  1. The Thermocline Layer and Chlorophyll-a Concentration Variability during Southeast Monsoon in the Banda Sea

    Science.gov (United States)

    Pusparini, Nikita; Prasetyo, Budi; Ambariyanto; Widowati, Ita

    2017-02-01

    Thermocline layer and chlorophyll-a concentration can be used to investigate the upwelling region. This investigation is focused in the Banda Sea because the upwelling event in this area is quite large and has a longer upwelling duration than other waters in Indonesia. In addition, Banda Sea is also influenced by climatic factors such as monsoon. The aim of this research is to determine the validation of secondary data (from satellite imagery data and model) and in situ observation data (from research cruise) and to determine the variability of thermocline layer and chlorophyll-a concentration during Southeast Monsoon in the Banda Sea. The data used in this study were chlorophyll-a concentration, seawater vertical temperature at depths 0-400 meters, and sea surface temperature from remote sensing and in situ data. Spatial and temporal analysis of all parameters was conducted by quantitative descriptive method. The results showed that the variability of thermocline layer and the chlorophyll-a distribution were strongly related to seasonal pattern. In most cases, the estimates of thermocline layer and chlorophyll-a concentration using remote sensing algorithm were higher than in situ measured values. The greatest variability occurred in the eastern Banda Sea during the Southeast Monsoon with shallower thermocline layer, more abundance of chlorophyll-a concentration, and lower sea surface temperature.

  2. Socio-economic research in support of climate policy development: Mistra's Research Program Clipore.

    Science.gov (United States)

    Grennfelt, Peringe; Kjellén, Bo; Linnér, Björn-Ola; Zetterberg, Lars

    2012-01-01

    Mistra's Climate Policy Research Program, Clipore, is one of the largest research programs directed to support international climate policy development, involving research groups in Sweden, Norway, United States and India. It has been running from 2004 to 2011 with a budget of more than 100 MSEK (15 M USD). The paper briefly describes the program and its outcomes in relation to climate policy development. Discussion focuses on how the program has been able to be in the front of and include the development of emissions trading systems in Europe and the United States and how the program has been able to follow and produce inputs to the agenda of the United Nations Framework Convention on Climate Change (UNFCCC). The paper also discusses how the program has managed to present its outcomes and maintain an active dialogue with the various stakeholders. The paper emphasises options and obstacles in the communication between science and policy.

  3. Overview of a new scenario framework for climate change research

    Science.gov (United States)

    Ebi, K. L.

    2013-12-01

    The scientific community is developing new integrated global, regional, and sectoral scenarios to facilitate interdisciplinary research and assessment to explore the range of possible future climates and related physical changes; the risks these could pose to human and natural systems, particularly how these changes could interact with social, economic, and environmental development pathways; the degree to which mitigation and adaptation policies can avoid and reduce the risks; the costs and benefits of various policy mixes; residual impacts under alternative pathways; and the relationship with sustainable development. Developing new scenarios for use in impacts, adaptation, and mitigation research requires more than emissions of greenhouse gases and resulting climate change. Scenarios also require assumptions about socioeconomic development, including a narrative, and qualitative and quantitative assumptions about development patterns. An insight recently gained is that the magnitude and extent of greenhouse gas emissions is relatively independent of demographic and socioeconomic development; that is, multiple demographic and socioeconomic development pathways can lead to any particular emission scenario. A relatively wealthy world with high population density could have low greenhouse gas emissions because of policies that encourage energy efficiency and sufficient low emission technology. The opposite also is plausible. Therefore, demographic and socioeconomic development pathways can be described separately from the Representative Concentration Pathways and then combined using a matrix architecture into a broader range of scenarios than was possible with the SRES. Shared Socioeconomic Pathways (SSPs) define the state of human and natural societies at a macro scale. To encompass a wide range of possible development pathways, five SSPs are defined along two axes describing worlds with increasing socioeconomic challenges to mitigation (y-axis) and adaptation (x

  4. Climate Comics: polar research in a cartoon form

    Science.gov (United States)

    Courville, Z.; Carbaugh, S.; Defrancis, G.; Donegan, R.; Brown, C.; Perovich, D. K.; Richter-Menge, J.

    2013-12-01

    Climate Comics is a collaborative outreach effort between the Montshire Museum of Science, in Norwich, VT, the Cold Regions Research and Engineering Laboratory (CRREL) research staff, and freelance artist and recent graduate of the Center for Cartoon Studies in White River Junction, VT, Sam Carbaugh. The project involves the cartoonist, the education staff from the museum, and researchers from CRREL creating a series of comic books with polar science and research themes, including sea ice monitoring, sea ice albedo, ice cores, extreme microbial activity, and stories and the process of fieldwork. The aim of the comic series is to provide meaningful science information in a comic-format that is both informative and fun, while highlighting current polar research work done at the lab. The education staff at the Montshire Museum develops and provides a series of hands-on, inquiry-based activity descriptions to complement each comic book, and CRREL researchers provide science background information and reiterative feedback about the comic books as they are being developed. Here, we present the motivation for using the comic-book medium to present polar research topics, the process involved in creating the comics, some unique features of the series, and the finished comic books themselves. Cartoon illustrating ways snow pack can be used to determine past climate information.

  5. Engaging the Global South on climate engineering research

    Science.gov (United States)

    Winickoff, David E.; Flegal, Jane A.; Asrat, Asfawossen

    2015-07-01

    The Global South is relatively under-represented in public deliberations about solar radiation management (SRM), a controversial climate engineering concept. This Perspective analyses the outputs of a deliberative exercise about SRM, which took place at the University of California-Berkeley and involved 45 mid-career environmental leaders, 39 of whom were from the Global South. This analysis identifies and discusses four themes from the Berkeley workshop that might inform research and governance in this arena: (1) the 'moral hazard' problem should be reframed to emphasize 'moral responsibility'; (2) climate models of SRM deployment may not be credible as primary inputs to policy because they cannot sufficiently address local concerns such as access to water; (3) small outdoor experiments require some form of international public accountability; and (4) inclusion of actors from the Global South will strengthen both SRM research and governance.

  6. Transformation in a changing climate: a research agenda

    OpenAIRE

    Fazey, I.; Moug, P; Allen, S.; Beckmann, K.; Blackwood, D; Bonaventura, M; Burnett, K.; Danson, M; Falconer, R; Gagnon, A; Harkness, R; Hodgson, A; Holm, L; Irvine, KN; Low, R

    2016-01-01

    The concept of transformation in relation to climate and other global change is increasingly receiving attention. The concept provides important opportunities to help examine how rapid and fundamental change to address contemporary global challenges can be facilitated. This paper contributes to discussions about transformation by providing a social science, arts and humanities perspective to open up discussion and set out a research agenda about what it means to transform and the dimensions, ...

  7. ARM Climate Research Facility Quarterly Value-Added Product Report

    Energy Technology Data Exchange (ETDEWEB)

    Sivaraman, Chitra

    2014-01-14

    The purpose of this report is to provide a concise status update for value-added products (VAP) implemented by the Atmospheric Radiation Measurement Climate Research Facility. The report is divided into the following sections: (1) new VAPs for which development has begun, (2) progress on existing VAPs, (3) future VAPs that have been recently approved, (4) other work that leads to a VAP, and (5) top requested VAPs from the archive.

  8. Growing Diversity in Space Weather and Climate Change Research

    Science.gov (United States)

    Johnson, L. P.; Ng, C.; Marchese, P.; Austin, S.; Frost, J.; Cheung, T. D.; Robbins, I.; Carlson, B. E.; Steiner, J. C.; Tremberger, G.; Paglione, T.; Damas, C.; Howard, A.; Scalzo, F.

    2013-12-01

    Space Weather and Global Climate Impacts are critical items on the present national and international science agendas. Understanding and forecasting solar activity is increasingly important for manned space flight, unmanned missions (including communications satellites, satellites that monitor the space and earth environment), and regional power grids. The ability to predict the effects of forcings and feedback mechanisms on global and local climate is critical to survival of the inhabitants of planet Earth. It is therefore important to motivate students to continue their studies via advanced degrees and pursue careers related to these areas. This CUNY-based initiative, supported by NASA and NSF, provided undergraduate research experience for more than 70 students in topics ranging from urban impacts of global climate change to magnetic rope structure, solar flares and CMEs. Other research topics included investigations of the ionosphere using a CubeSat, stratospheric aerosols in Jupiter's atmosphere, and ocean climate modeling. Mentors for the primarily summer research experiences included CUNY faculty, GISS and GSFC scientists. Students were recruited from CUNY colleges as well as other colleges including Spelman, Cornell, Rutgers and SUNY colleges. Fifty-eight percent of the undergraduate students were under-represented minorities and thirty-four percent were female. Many of the research teams included high school teachers and students as well as graduate students. Supporting workshops for students included data analysis and visualization tools, space weather, planetary energy balance and BalloonSats. The project is supported by NASA awards NNX10AE72G and NNX09AL77G, and NSF REU Site award 0851932.

  9. ARM Climate Research Facility Quarterly Ingest Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Koontz, A. [DOE ARM Climate Research Facility, Washington, DC (United States); Sivaraman, C. [DOE ARM Climate Research Facility, Washington, DC (United States)

    2016-10-01

    The purpose of this report is to provide a concise status update for ingests maintained by the Atmospheric Radiation Measurement (ARM) Climate Research Facility. The report is divided into the following sections: (1) new ingests for which development has begun, (2) progress on existing ingests, (3) future ingests that have been recently approved, (4) other work that leads to an ingest, and (5) top requested ingests from the ARM Data Archive. New information is highlighted in blue text.

  10. ARM Climate Research Facility Quarterly Ingest Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Koontz, A. [ARM Climate Reesearch Facility, Washington, DC (United States); Sivaraman, C. [ARM Climate Reesearch Facility, Washington, DC (United States)

    2016-07-01

    The purpose of this report is to provide a concise status update for ingests maintained by the Atmospheric Radiation Measurement (ARM) Climate Research Facility. The report is divided into the following sections: (1) new ingests for which development has begun, (2) progress on existing ingests, (3) future ingests that have been recently approved, (4) other work that leads to an ingest, and (5) top requested ingests from the ARM Data Archive. New information is highlighted in blue text.

  11. ARM Climate Research Facility Quarterly Value-Added Product Report

    Energy Technology Data Exchange (ETDEWEB)

    Sivaraman, Chitra

    2013-07-31

    The purpose of this report is to provide a concise status update for value-added products (VAP) implemented by the Atmospheric Radiation Measurement Climate Research Facility. The report is divided into the following sections: (1) new VAPs for which development has begun, (2) progress on existing VAPs, (3) future VAPs that have been recently approved, (4) other work that leads to a VAP, and (5) top requested VAPs from the archive.

  12. Onset of Indian Summer Monsoon: a retrospective analysis

    Science.gov (United States)

    Sruthi, S.; Mrudula, G.

    2016-05-01

    The monsoon onset over Kerala is considered as the beginning of rain fall over India and it is the end of hot summer. Different criteria have been used to define the monsoon onset over Kerala, with the one given by India Meteorological Department taken as the standard criteria. The analysis of the past 20 years of observations shows that the variables during the monsoon onset do not behave in the same way always. The purpose of this paper is to analyses the monsoon onset phases and to find possible reasons behind the variable nature of the monsoon onset. Different meteorological parameters like precipitation, outgoing long wave radiation (OLR), winds, air temperature, and specific humidity at different levels are analyzed for the same. Research has been done on various distinct features of monsoon such as Low Level Jet (LLJ), Tropical Easterly Jet (TEJ), monsoon trough, and depressions etc., during the onset phase. The analysis showed that in some years the strength of LLJ is lesser compared to the normal years. It is also seen that in some years the wind flow pattern is different from that observed during a standard onset year. The results of these analyses will be presented in detail in the paper.

  13. Characteristics of monsoon waves off Uran, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nayak, B.U.; Chandramohan, P.; Mandal, S.

    's and the spectral methods for determining various wave parameters. Monsoon wave climate was stronger with the occurrence of the highest significant wave height of 2.45 m and the corresponding maximum wave height of 3.9 m in July. Significant wave height varied from...

  14. Morphodynamics of tidal inlets in a tropical monsoon area

    NARCIS (Netherlands)

    Lam, N.T.; Stive, M.J.F.; Verhagen, H.J.; Wang, Z.B.

    2007-01-01

    Morphodynamics of a tidal inlet system on a micro-tidal coast in a tropical monsoon influenced region is modelled and discussed. Influences of river flow and wave climate on the inlet morphology are investigated with the aid of process-based state-of-the-art numerical models. Seasonal and episodic b

  15. Global monsoon precipitation responses to large volcanic eruptions.

    Science.gov (United States)

    Liu, Fei; Chai, Jing; Wang, Bin; Liu, Jian; Zhang, Xiao; Wang, Zhiyuan

    2016-04-11

    Climate variation of global monsoon (GM) precipitation involves both internal feedback and external forcing. Here, we focus on strong volcanic forcing since large eruptions are known to be a dominant mechanism in natural climate change. It is not known whether large volcanoes erupted at different latitudes have distinctive effects on the monsoon in the Northern Hemisphere (NH) and the Southern Hemisphere (SH). We address this issue using a 1500-year volcanic sensitivity simulation by the Community Earth System Model version 1.0 (CESM1). Volcanoes are classified into three types based on their meridional aerosol distributions: NH volcanoes, SH volcanoes and equatorial volcanoes. Using the model simulation, we discover that the GM precipitation in one hemisphere is enhanced significantly by the remote volcanic forcing occurring in the other hemisphere. This remote volcanic forcing-induced intensification is mainly through circulation change rather than moisture content change. In addition, the NH volcanic eruptions are more efficient in reducing the NH monsoon precipitation than the equatorial ones, and so do the SH eruptions in weakening the SH monsoon, because the equatorial eruptions, despite reducing moisture content, have weaker effects in weakening the off-equatorial monsoon circulation than the subtropical-extratropical volcanoes do.

  16. Paleoclimate and Asian monsoon variability inferred from n-alkanes and their stable isotopes at lake Donggi Cona, NE Tibetan Plateau

    Science.gov (United States)

    Saini, Jeetendra; Guenther, Franziska; Mäusbacher, Roland; Gleixner, Gerd

    2015-04-01

    The Tibetan Plateau is one of the most extensive and sensitive region of elevated topography affecting global climate. The interplay between the Asian summer monsoon and the westerlies greatly influences the lake systems at the Tibetan Plateau. Despite a considerable number of research efforts in last decade, possible environmental reactions to change in monsoon dynamics are still not well understood. Here we present results from a sediment core of lake Donggi Cona, which dates back to late glacial period. Distinct organic geochemical proxies and stable isotopes are used to study the paleoenvironmental and hydrological changes in late glacial and Holocene period. Sedimentary n-alkanes of lake Donggi Cona are used as a proxy for paleoclimatic and monsoonal reconstruction. The hydrogen (δD) and carbon (δ13C) isotopes of n-alkanes are used as proxy for hydrological and phytoplankton productivity, respectively . Qualitative and quantitative analysis were performed for n-alkanes over the sediment core. δD proxy for sedimentary n-alkanes is used to infer lake water and rainfall signal. δD of (n-alkane C23) records the signal of the lake water, whereas δD of (n-alkane C29) record the precipitation signal, hence act as an appropriate proxy to track Asian monsoon. Long chain n-alkanes dominate over the sediment core while unsaturated mid chain n-alkenes have high abundance in some samples. From 18.4-13.8 cal ka BP, sample shows low organic productivity due to cold and arid climate. After 13.8-11.8 cal ka BP, slight increase in phytoplankton productivity indicate onset of weaker monsoon. From 11.8-6.8 cal ka BP, high content of organic matter indicates rise in productivity and strong monsoon with high inflow. After 6.8 cal ka BP, decrease in phytoplankton productivity indicating cooler climate and show terrestrial signal. Our results provide new insight into the variability of east Asian monsoon and changes in phytoplankton productivity for last 18.4 ka. Keywords: n

  17. Climate adaptation - 5 key research themes; Denmark; Klimatilpasning - 5 centrale forskningstemaer

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Bent; Binnerup, S.; Bijl, L. van der; Villholth, K.G.; Drews, M.; Strand, I.F.; Henrichs, T.; Larsen, Niels; Timmermann, T.; Moseholm, L.

    2009-06-15

    The report proposes five key research themes under the heading 'Future climate and climate adaptation' which can support the Danish climate adaptation efforts. These themes underpin climate adaptation in the light of research needs identified by the research environments and sectors under the government's strategy on adaptation to climate change in Denmark from March 2008. The paper has been prepared within the framework of RESEARCH2015-proposal by the Ministry of Science, Technology and Innovation in order to bring about the knowledge and tools that are demanded by sectors and authorities to implement the government's climate adaptation strategy. This concept paper for research themes is a thorough, holistic and inter-sectoral suggestion for future research priorities in climate adaptation with anchoring in both the research community as well as in the political-administrative system. The five key themes are; 1. Models and climate adaptation; 2. Communities and climate adaptation; 3. Construction and climate adaptation; 4. Landscape and climate adaptation; 5. Climate adaptation in the coastal zone. The overall research needs over a 5 year period is estimated at 700 million DKK, of which 85 million DKK yearly can be estimated to be financed primarily through national basic funds and research council funds. Research is assumed to be coupled to external financing, for which the EU's 7th Framework Program and the Nordic excellence and innovation program in the energy, climate and environment will be significant sources.

  18. THE IMPACT OF THERMAL ENGINEERING RESEARCH ON GLOBAL CLIMATE CHANGE

    Energy Technology Data Exchange (ETDEWEB)

    Phelan, Patrick [Arizona State University; Abdelaziz, Omar [ORNL; Otanicar, Todd [University of Tulsa; Phelan, Bernadette [Phelan Research Solutions, Inc.; Prasher, Ravi [Arizona State University; Taylor, Robert [University of New South Wales, Sydney, Australia; Tyagi, Himanshu [Indian Institute of Technology Ropar, India

    2014-01-01

    Global climate change is recognized by many people around the world as being one of the most pressing issues facing our society today. The thermal engineering research community clearly plays an important role in addressing this critical issue, but what kind of thermal engineering research is, or will be, most impactful? In other words, in what directions should thermal engineering research be targeted in order to derive the greatest benefit with respect to global climate change? To answer this question we consider the potential reduction in greenhouse gas (GHG) emissions, coupled with potential economic impacts, resulting from thermal engineering research. Here a new model framework is introduced that allows a technological, sector-by-sector analysis of GHG emissions avoidance. For each sector, we consider the maximum reduction in CO2 emissions due to such research, and the cost effectiveness of the new efficient technologies. The results are normalized on a country-by-country basis, where we consider the USA, the European Union, China, India, and Australia as representative countries or regions. Among energy supply-side technologies, improvements in coal-burning power generation are seen as having the most beneficial CO2 and economic impacts. The one demand-side technology considered, residential space cooling, offers positive but limited impacts. The proposed framework can be extended to include additional technologies and impacts, such as water consumption.

  19. Modelling Monsoons: Understanding and Predicting Current and Future Behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Turner, A; Sperber, K R; Slingo, J M; Meehl, G A; Mechoso, C R; Kimoto, M; Giannini, A

    2008-09-16

    The global monsoon system is so varied and complex that understanding and predicting its diverse behaviour remains a challenge that will occupy modellers for many years to come. Despite the difficult task ahead, an improved monsoon modelling capability has been realized through the inclusion of more detailed physics of the climate system and higher resolution in our numerical models. Perhaps the most crucial improvement to date has been the development of coupled ocean-atmosphere models. From subseasonal to interdecadal timescales, only through the inclusion of air-sea interaction can the proper phasing and teleconnections of convection be attained with respect to sea surface temperature variations. Even then, the response to slow variations in remote forcings (e.g., El Nino-Southern Oscillation) does not result in a robust solution, as there are a host of competing modes of variability that must be represented, including those that appear to be chaotic. Understanding the links between monsoons and land surface processes is not as mature as that explored regarding air-sea interactions. A land surface forcing signal appears to dominate the onset of wet season rainfall over the North American monsoon region, though the relative role of ocean versus land forcing remains a topic of investigation in all the monsoon systems. Also, improved forecasts have been made during periods in which additional sounding observations are available for data assimilation. Thus, there is untapped predictability that can only be attained through the development of a more comprehensive observing system for all monsoon regions. Additionally, improved parameterizations - for example, of convection, cloud, radiation, and boundary layer schemes as well as land surface processes - are essential to realize the full potential of monsoon predictability. Dynamical considerations require ever increased horizontal resolution (probably to 0.5 degree or higher) in order to resolve many monsoon features

  20. Atmospheric Radiation Measurement Climate Research Facility Annual Report 2006

    Energy Technology Data Exchange (ETDEWEB)

    LR Roeder

    2005-11-30

    This annual report describes the purpose and structure of the ARM Climate Research Facility and ARM Science programs and presents key accomplishments in 2006. Noteworthy scientific and infrastructure accomplishments in 2006 include: • Collaborating with the Australian Bureau of Meteorology to lead the Tropical Warm Pool-International Cloud Experiment, a major international field campaign held in Darwin, Australia • Successfully deploying the ARM Mobile Facility in Niger, Africa • Developing the new ARM Aerial Vehicles Program (AVP) to provide airborne measurements • Publishing a new finding on the impacts of aerosols on surface energy budget in polar latitudes • Mitigating a long-standing double-Intertropical Convergence Zone problem in climate models using ARM data and a new cumulus parameterization scheme.

  1. Asian Summer Monsoon and its Associated Rainfall Variability in Thailand

    Directory of Open Access Journals (Sweden)

    Atsamon Limsakul

    2010-07-01

    Full Text Available The Asian monsoon is an important component of the Earth's climate. Its associated rainfall variability is a crucial fac¬tor for Thailand's socio-economic development, water resources and agricultural management. An analysis shows that the Thailand rainfall annual cycle is in phase with the Indian summer monsoon (ISM and the western North Pacific summer monsoon (WNPSM. On the basis of the Empirical Orthogonal Function (EOF analysis, the dominant spatial-temporal interannual variability in summer monsoon rainfall (Jun.-Sep. during 1975-2006 could be explained by the first two EOF modes, accounting for 34% of the total variance. The EOF1 was spatially dominated by strong positive signals in the central and east, whereas the EOF2 exhibited dipole variability. The coefficient time series of EOF1 significantly correlated posi¬tively with ISM index, but negatively with WNPSM index. The results suggest that summer monsoon rainfall in Thailand is higher (lower than normal during the strengthening (weakening of ISM. In contrast, rainfall in the north-east (central is surplus (deficit during the strengthening (weakening of WNPSM. These findings imply that, on an interannual time scale, ISM and WNPSM exert their influence to a different extent on summer monsoon rainfall in Thailand. A clear picture of linking mechanisms and interactions with another climate mode in the Indo-Pacific sector needs to be understood. This knowledge is essential for effectively adapting to climate-related hazards and rainfall extremes and for better management of water resource and agriculture in Thailand, especially under current/future warming conditions.

  2. What drives cold-related excess mortality in a south Asian tropical monsoon climate-season vs. temperatures and diurnal temperature changes

    Science.gov (United States)

    Burkart, Katrin; Kinney, Patrick L.

    2016-12-01

    Despite the tropical climate which is characterized by generally high temperatures and persistent mild temperatures during the winter season, Bangladesh, along with many other tropical countries, experiences strong winter and cold-related excess mortality. The objective of this paper was to analyse the nature of these cold effects and understand the role of season vs. temperature and diurnal changes in temperature. For approaching these questions, we applied different Poisson regression models. Temperature as well as diurnal temperature range (DTR) were considered as predictor variables. Different approaches to seasonality adjustment were evaluated and special consideration was given to seasonal differences in atmospheric effects. Our findings show that while seasonality adjustment affected the magnitude of cold effects, cold-related mortality persisted regardless the adjustment approach. Strongest effects of low temperatures were observed at the same day (lag 1) with an increase of 1.7% (95% CI = 0.86-2.54%) per 1 °C decrease in temperature during the winter season. Diurnal temperature affected mortality with increasing levels at higher ranges. Mortality increased with 0.97% (95% CI = 0.17-1.75%) when looking at the entire season, but effects of DTR were not significant during winter when running a seasonal model. Different from effects observed in the mid-latitudes, cold effects in Bangladesh occurred on a very short time scale highlighting the role of temperature versus season. Insufficient adaptation with regard to housing and clothing might lead to such cold-related increases in mortality despite rather moderate temperature values. Although the study did not demonstrate an effect of DTR during the cold season, the strong correlation with (minimum) temperature might cause a multicollinearity problem and effects are difficult to attribute to one driver.

  3. AGU Journals Among Most Cited Publications in Climate Change Research

    Science.gov (United States)

    Sears, Jon

    2010-03-01

    Geophysical Research Letters (GRL) and Journal of Geophysical Research-Atmospheres (JGR-D) both ranked among the top 10 of the most highly cited research publications on climate change over the past decade in a recent analysis by sciencewatch.com, an Internet tool published by the Thomson Reuters Web of Science® that tracks trends and performances in basic research. Although Nature and Science—the multidisciplinary heavyweights—led the field, GRL ranked fifth and JGR-D ranked sixth. The study was conducted by searching the Web of Science® database for terms such as “global warming,” “climate change,” “human impact,” and other key phrases in journal articles published and cited between 1999 and the spring of 2009. The analysis produced over 28,000 papers, from which sciencewatch.com identified the most cited institutions, authors, and journals. To see the analysis in full, visit http://sciencewatch.com/ana/fea/09novdecFea/.

  4. Tropical-Extratropical Interactions and Intrasasonal Oscillations in the Indian Monsoon System in a Warmer Planet

    Science.gov (United States)

    Carvalho, L. V.; Jones, C.; Cannon, F.; Norris, J.

    2015-12-01

    The India summer monsoon (ISM) experiences long periods of wet and dry conditions frequently associated with floods and long dry spells. These events are largely governed by northward propagating boreal summer monsoon intraseasonal oscillations (MISO). Here we investigate intraseasonal variability of the ISM in the climate of the 20th century using the Climate Forecast System Reanalysis (1979-2013) and examine future scenarios of climate change using models of the Coupled Model Intercomparison Project Phase-5 project. ISM is characterized with a large-scale index obtained by performing combined EOF analysis of precipitation, low level circulation, specific humidity and temperature. This index realistically defines the monsoon's onset and withdrawal, is well correlated with seasonal precipitation in India and exhibits variance on intraseasonal timescales that are related to MISO and extreme wet and dry conditions in India. With similar approach we investigate the skill of the CMIP5 models in realistically simulating MISO in the 'historic' run (1951-2005) and examine projected changes in the amplitude and persistence these events in the high-emission representative concentration pathway 8.5 (RCP8.5) (2006-2100). MISO is well characterized in CMIP5 models that indicate significant increase in the intensity and frequency of extremely dry and wet conditions affecting India by 2050. We show that the main mechanism driving MISO in CMIP5 models are linked to the propagation of extratropical wave trains and interactions with the tropics. In a warmer planet, the increase in polar temperatures weakens the tropical-extratropical temperature gradient and decreases the intensity of the upper tropospheric jet. These changes in the jet and in the baroclinic structure of the atmosphere result in enhanced extratropical wave activity and more extreme events. We use a wave tracking algorithm to demonstrate these differences and explore physical and dynamical mechanisms underlying

  5. Research Advances of Impacts of Climate Changes on Crop Climatic Adaptability

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Agriculture received most direct influences from climate changes. Because of climate changes, agricultural climate resources changed and thus influenced climate adaptability of agricultural products. The growth and output of crops were finally affected. The calculation method and application of agricultural products in recent years were summarized. Several questions about the response of agricultural crops to climate elements were proposed for attention.

  6. Towards Understanding Planetary Boundary Layer Regimes in Relation to Indian Summer Monsoon

    Science.gov (United States)

    Sathyanadh, A.

    2015-12-01

    Atmospheric boundary layer processes play crucial role in modulating weather and climate of the earth. Information on the planetary boundary layer characteristics are important in various aspects. Analyses presented in the study are mainly carried out using Modern Era Retrospective analysis for Research and Applications (MERRA) reanalysis data products. Hourly values of PBL height, soil moisture, fluxes, cloud cover, and atmospheric stability in the region 5-38° N, 60 - 100o E are used. The MERRA PBL heights are validated with PBL heights calculated using GPS RO atmospheric profiles during 2007-09 and radiosonde observations in order to assess the suitability of MERRA data for the PBL analysis. The radiosonde data used are from two sources: (i) routine radiosonde observations conducted by India Meteorological Department over the Indian subcontinent and (ii) additional radiosonde observations conducted by the Indian Institute of Tropical Meteorology as a part of the Cloud Aerosol Interaction and Precipitation Enhancement Experiment during theSW monsoon, 2009. Spatio-temporal variations of PBL height in relation to different phases of monsoon and intra-seasonal variations are investigated in detail. Seasonal variations show a deeper premonsoon boundary layer and a shallower monsoon boundary layer, with large spatial variations. The PBLH variations over inland locations are found to be in good agreement with onset and progress of monsoon rainfall and associated soil moisture variations. The active and break spell monsoon PBL heights analyzed using 20-year PBL data showed deeper PBLHs during break periods compared to active period. Based on the maximum PBLH and growth characteristics, different regimes are identified which are mainly controlled by soil moisture/ evaporative fraction, but further influenced by stability of the surface, cloudiness, wind shear, etc. resulting in complex PBL regimes in relation to monsoon. The maximum PBLH, growth rate, time of occurrence

  7. Carbon, Climate and Cameras: Showcasing Arctic research through multimedia storytelling

    Science.gov (United States)

    Tachihara, B. L.; Linder, C. A.; Holmes, R. M.

    2011-12-01

    In July 2011, Tachihara spent three weeks in the Siberian Arctic documenting The Polaris Project, an NSF-funded effort that brings together an international group of undergraduate students and research scientists to study Arctic systems. Using a combination of photography, video and interviews gathered during the field course, we produced a six-minute film focusing on the researchers' quest to track carbon as it moves from terrestrial upland areas into lakes, streams, rivers and eventually into the Arctic Ocean. The overall goal was to communicate the significance of Arctic science in the face of changing climate. Using a selection of clips from the 2011 video, we will discuss the advantages and challenges specific to using multimedia presentations to represent Arctic research, as well as science in general. The full video can be viewed on the Polaris website: http://www.thepolarisproject.org.

  8. A new scenario framework for climate change research: the concept of shared climate policy assumptions

    NARCIS (Netherlands)

    Kriegler, E.; Edmonds, J.; Hallegatte, S.; Ebi, K.L.; Kram, T.; Riahi, K.; Winkler, J.; van Vuuren, Detlef|info:eu-repo/dai/nl/11522016X

    2014-01-01

    The new scenario framework facilitates the coupling of multiple socioeconomic reference pathways with climate model products using the representative concentration pathways. This will allow for improved assessment of climate impacts, adaptation and mitigation. Assumptions about climate policy play a

  9. Atlantic effects on recent decadal trends in global monsoon

    Science.gov (United States)

    Kamae, Youichi; Li, Xichen; Xie, Shang-Ping; Ueda, Hiroaki

    2017-01-01

    Natural climate variability contributes to recent decadal climate trends. Specifically the trends during the satellite era since 1979 include Atlantic and Indian Ocean warming and Pacific cooling associated with phase shifts of the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation, and enhanced global monsoon (GM) circulation and rainfall especially in the Northern Hemisphere. Here we evaluate effects of the oceanic changes on the global and regional monsoon trends by partial ocean temperature restoring experiments in a coupled atmosphere-ocean general circulation model. Via trans-basin atmosphere-ocean teleconnections, the Atlantic warming drives a global pattern of sea surface temperature change that resembles observations, giving rise to the enhanced GM. The tropical Atlantic warming and the resultant Indian Ocean warming favor subtropical deep-tropospheric warming in both hemispheres, resulting in the enhanced monsoon circulations and precipitation over North America, South America and North Africa. The extratropical North Atlantic warming makes an additional contribution to the monsoon enhancement via Eurasian continent warming and resultant land-sea thermal gradient over Asia. The results of this study suggest that the Atlantic multidecadal variability can explain a substantial part of global climate variability including the recent decadal trends of GM.

  10. Langley Research Center Utility Risk from Future Climate Change

    Science.gov (United States)

    De Young, Russell J.; Ganoe, Rene

    2015-01-01

    The successful operation of NASA Langley Research Center (LaRC) depends on services provided by several public utility companies. These include Newport News Waterworks, Dominion Virginia Power, Virginia Natural Gas and Hampton Roads Sanitation District. LaRC's plan to respond to future climate change should take into account how these companies plan to avoid interruption of services while minimizing cost to the customers. This report summarizes our findings from publicly available documents on how each company plans to respond. This will form the basis for future planning for the Center. Our preliminary findings show that flooding and severe storms could interrupt service from the Waterworks and Sanitation District but the potential is low due to plans in place to address climate change on their system. Virginia Natural Gas supplies energy to produce steam but most current steam comes from the Hampton trash burning plant, thus interruption risk is low. Dominion Virginia Power does not address climate change impacts on their system in their public reports. The potential interruption risk is considered to be medium. The Hampton Roads Sanitation District is projecting a major upgrade of their system to mitigate clean water inflow and infiltration. This will reduce infiltration and avoid overloading the pump stations and treatment plants.

  11. Indian Summer Monsoon Rainfall: Implications of Contrasting Trends in the Spatial Variability of Means and Extremes.

    Directory of Open Access Journals (Sweden)

    Subimal Ghosh

    Full Text Available India's agricultural output, economy, and societal well-being are strappingly dependent on the stability of summer monsoon rainfall, its variability and extremes. Spatial aggregate of intensity and frequency of extreme rainfall events over Central India are significantly increasing, while at local scale they are spatially non-uniform with increasing spatial variability. The reasons behind such increase in spatial variability of extremes are poorly understood and the trends in mean monsoon rainfall have been greatly overlooked. Here, by using multi-decadal gridded daily rainfall data over entire India, we show that the trend in spatial variability of mean monsoon rainfall is decreasing as exactly opposite to that of extremes. The spatial variability of extremes is attributed to the spatial variability of the convective rainfall component. Contrarily, the decrease in spatial variability of the mean rainfall over India poses a pertinent research question on the applicability of large scale inter-basin water transfer by river inter-linking to address the spatial variability of available water in India. We found a significant decrease in the monsoon rainfall over major water surplus river basins in India. Hydrological simulations using a Variable Infiltration Capacity (VIC model also revealed that the water yield in surplus river basins is decreasing but it is increasing in deficit basins. These findings contradict the traditional notion of dry areas becoming drier and wet areas becoming wetter in response to climate change in India. This result also calls for a re-evaluation of planning for river inter-linking to supply water from surplus to deficit river basins.

  12. Indian Summer Monsoon Rainfall: Implications of Contrasting Trends in the Spatial Variability of Means and Extremes.

    Science.gov (United States)

    Ghosh, Subimal; Vittal, H; Sharma, Tarul; Karmakar, Subhankar; Kasiviswanathan, K S; Dhanesh, Y; Sudheer, K P; Gunthe, S S

    2016-01-01

    India's agricultural output, economy, and societal well-being are strappingly dependent on the stability of summer monsoon rainfall, its variability and extremes. Spatial aggregate of intensity and frequency of extreme rainfall events over Central India are significantly increasing, while at local scale they are spatially non-uniform with increasing spatial variability. The reasons behind such increase in spatial variability of extremes are poorly understood and the trends in mean monsoon rainfall have been greatly overlooked. Here, by using multi-decadal gridded daily rainfall data over entire India, we show that the trend in spatial variability of mean monsoon rainfall is decreasing as exactly opposite to that of extremes. The spatial variability of extremes is attributed to the spatial variability of the convective rainfall component. Contrarily, the decrease in spatial variability of the mean rainfall over India poses a pertinent research question on the applicability of large scale inter-basin water transfer by river inter-linking to address the spatial variability of available water in India. We found a significant decrease in the monsoon rainfall over major water surplus river basins in India. Hydrological simulations using a Variable Infiltration Capacity (VIC) model also revealed that the water yield in surplus river basins is decreasing but it is increasing in deficit basins. These findings contradict the traditional notion of dry areas becoming drier and wet areas becoming wetter in response to climate change in India. This result also calls for a re-evaluation of planning for river inter-linking to supply water from surplus to deficit river basins.

  13. Climate Literacy Through Student-Teacher-Scientist Research Partnerships

    Science.gov (United States)

    Niepold, F.; Brooks, D.; Lefer, B.; Linsley, A.; Duckenfield, K.

    2006-12-01

    Expanding on the GLOBE Program's Atmosphere and Aerosol investigations, high school students can conduct Earth System scientific research that promotes scientific literacy in both content and the science process. Through the use of Student-Teacher-Scientist partnerships, Earth system scientific investigations can be conducted that serve the needs of the classroom as well as participating scientific investigators. During the proof-of-concept phase of this partnership model, teachers and their students developed science plans, through consultation with scientists, and began collecting atmospheric and aerosol data in support of the Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) campaign in Houston Texas. This effort uses some pre-existing GLOBE materials, but draws on a variety of other resources to tailor the teacher development activities and intended student participation in a way that addresses local and regional problems. Students and teachers have learned about best practices in scientific inquiry and they also helped to expand the pipeline of potential future scientists and researchers for industry, academia, and government. This work began with a Student-Teacher-Scientist partnership started in 2002 during a GLOBE Aerosol Protocol Cross- Ground Validation of AERONET with MODIS Satellite Aerosol Measurements. Several other GLOBE schools, both national and international, have contributed to this research. The current project support of the intensive GoMACCS air quality and atmospheric dynamics field campaign during September and October of 2006. This model will be evaluated for wider use in other project-focused partnerships led by NOAA's Climate Program Office.

  14. The use of climate research in the management of climatic changes; Bruk av klimaforskning i haandteringen av klimaendringer

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Knut H.

    2008-07-01

    The presentation aims at clarifying what is needed for increasing the influence of the climate research on development of policies and practical decisions. Various communication models are discussed with focus on relevance of the knowledge to be communicated and possible relationships between policies and knowledge, and aids such as regulations and standards. Some implications of the research are discussed and more emphasis on relevancy and political and managerial translations of the climatic research (tk)

  15. Participatory Climate Research in a Dynamic Urban Context

    Science.gov (United States)

    Horton, R. M.

    2016-12-01

    The Consortium for Climate Risk in the Urban Northeast (CCRUN), one of ten NOAA-RISA's, supports resilience efforts in the urban corridor stretching from Philadelphia to Boston. Challenges and opportunities include the diverse set of needs in broad urban contexts, as well as the integration of interdisciplinary perspectives. CCRUN is addressing these challenges through 1) stakeholder surveys, 2) webinar series that enable scientists to engage with stakeholders, 3) leveraging extreme events as focusing opportunities, and 4) the development of an integrated project framework. Moving forward, increasing extreme events can lead to unexpected detours, and further effort is needed around facilitating place-based research in an interdisciplinary context.

  16. Global Climate Change: Federal Research on Possible Human Health Effects

    Science.gov (United States)

    2006-02-10

    conditioning systems.”20 A recent rise in one measure of poverty in the United States is argued by some to suggest that there may be more poor ...conclusions are common to several studies on possible health effects of climate change: the infirm, the elderly, and the poor may be disproportionately...Global Change Research Program, op. cit. 20 Ibid. 21 Madrick, Jeff. A Rise in Child Poverty Rates Is At Risk In U.S., the New York Times on the Web, June

  17. Tracking Middle Grades Climate Data to Inform School Change. REL West Research Digest

    Science.gov (United States)

    Regional Educational Laboratory West, 2015

    2015-01-01

    A growing body of research shows that positive school climate is a key lever for students' academic and social development and success. This research digest shows how an alliance of California schools and districts, school climate experts, and state education agency personnel have teamed up to use school climate data to drive a continuous cycle of…

  18. Global warming and South Indian monsoon rainfall-lessons from the Mid-Miocene.

    Science.gov (United States)

    Reuter, Markus; Kern, Andrea K; Harzhauser, Mathias; Kroh, Andreas; Piller, Werner E

    2013-04-01

    Precipitation over India is driven by the Indian monsoon. Although changes in this atmospheric circulation are caused by the differential seasonal diabatic heating of Asia and the Indo-Pacific Ocean, it is so far unknown how global warming influences the monsoon rainfalls regionally. Herein, we present a Miocene pollen flora as the first direct proxy for monsoon over southern India during the Middle Miocene Climate Optimum. To identify climatic key parameters, such as mean annual temperature, warmest month temperature, coldest month temperature, mean annual precipitation, mean precipitation during the driest month, mean precipitation during the wettest month and mean precipitation during the warmest month the Coexistence Approach is applied. Irrespective of a ~ 3-4 °C higher global temperature during the Middle Miocene Climate Optimum, the results indicate a modern-like monsoonal precipitation pattern contrasting marine proxies which point to a strong decline of Indian monsoon in the Himalaya at this time. Therefore, the strength of monsoon rainfall in tropical India appears neither to be related to global warming nor to be linked with the atmospheric conditions over the Tibetan Plateau. For the future it implies that increased global warming does not necessarily entail changes in the South Indian monsoon rainfall.

  19. 基于动力反演方法的亚洲季风机制探讨%The Exploring of the Asian Monsoon Driving Mechanism Based on Dynamical Inversion Method

    Institute of Scientific and Technical Information of China (English)

    李玉霞; 林振山; 刘会玉

    2015-01-01

    The monsoon driving mechanism is a hot spot in the quaternary global change research, where the in-ternational academia has been paid close attention. As early as in 1686, Halley has put forward that the heat dif-ferences caused by the sun between the marine and terrestrial bring about the monsoon. With the deepening of the research, different driving factors are proposed one after another, such as the solar activity, the mechanical force and thermal effect of the Qinghai-Tibet Plateau, ENSO, the temperature of the south and north poles, the migration of the intertropical convergence zone, the thermohaline circulation and so on in which the solar activ-ity and the thermohaline circulation are widely accepted. Cave stalagmites oxygen isotope is one of the most important high-resolution alternative indexes of palaeoclimate. Especially in the region strongly affected by the monsoon, the change of the values of stalagmiteδ18O is often taken as the index of ancient monsoon intensi-ty. The Asian monsoon is an important part of the global climate system. Usually the Asian monsoon can be di-vided into East Asia monsoon and Indian monsoon, but the two monsoon regions have no clear boundary. So it is hard to verdict which monsoon the stalagmite collected from this convergence zone represents. Dongge cave is just located in the convergence zone, as is mentioned above,and which monsoon the stalagmiteδ18O value of Dongge Cave represents is still controversial. By means of the dynamic inversion analysis of the Asian mon-soon, the following results are obtained:1) The stalagmitesδ18O value of Dongge Cave is more likely to repre-sent the Indian monsoon. The Indian monsoon system is a complex nonlinear dynamic system driven by the Antarctic temperature and other factors. 2) The solar activity plays a negative feedback stabilizing role in the Indian monsoon system. The stronger the solar activity is, the weaker the stabilization role it plays will be. The temperature of the

  20. Indian monsoon variability on millennial-orbital timescales.

    Science.gov (United States)

    Kathayat, Gayatri; Cheng, Hai; Sinha, Ashish; Spötl, Christoph; Edwards, R Lawrence; Zhang, Haiwei; Li, Xianglei; Yi, Liang; Ning, Youfeng; Cai, Yanjun; Lui, Weiguo Lui; Breitenbach, Sebastian F M

    2016-04-13

    The Indian summer monsoon (ISM) monsoon is critical to billions of people living in the region. Yet, significant debates remain on primary ISM drivers on millennial-orbital timescales. Here, we use speleothem oxygen isotope (δ(18)O) data from Bittoo cave, Northern India to reconstruct ISM variability over the past 280,000 years. We find strong coherence between North Indian and Chinese speleothem δ(18)O records from the East Asian monsoon domain, suggesting that both Asian monsoon subsystems exhibit a coupled response to changes in Northern Hemisphere summer insolation (NHSI) without significant temporal lags, supporting the view that the tropical-subtropical monsoon variability is driven directly by precession-induced changes in NHSI. Comparisons of the North Indian record with both Antarctic ice core and sea-surface temperature records from the southern Indian Ocean over the last glacial period do not suggest a dominant role of Southern Hemisphere climate processes in regulating the ISM variability on millennial-orbital timescales.

  1. Climate research, citizen science and art in Bangladesh

    Science.gov (United States)

    Stiller-Reeve, Mathew; Naznin, Zakia; Blanchard, Anne; Bremer, Scott

    2017-04-01

    Our research project focuses on climate information for adaptation in the northeast region of Bangladesh. In this project, we work closely with local rural communities. Since these local people are carrying out citizen science together, then a sense of community and good team spirit are essential for success. We collaborated with a Bangladeshi artist to achieve some important goals. Not only did we want to create new and exciting outreach materials, we -more importantly- wanted to see how the artistic process could nurture a sense of community for the local participants. Despite being limited by time, we saw some promising outcomes from the collaboration. The artist successfully interacted with the project researchers and the local participants. The final artwork was a real collaboration between the artist and the participants whom felt pride and ownership in the results.

  2. Monsoonal Variations of Supraglacial Lakes, Langtang Khola, Nepal

    Science.gov (United States)

    Miles, E. S.; Willis, I. C.; Arnold, N. S.; Pellicciotti, F.

    2013-12-01

    As Himalayan debris-covered glaciers retreat and thin in response to climate warming, their long, low-gradient tongues and undulating surfaces tend to form supraglacial lakes. The conceptual response of debris-covered valley glaciers progresses from thinning and stagnation to the development of supraglacial ponds, which eventually may coalesce into very large lakes bounded by terminal moraines. Large terminal lakes are a topic of frequent study due to the public safety hazard of glacier lake outburst floods (GLOFs). However, smaller, transient ponds that form on the glacier's surface may play an important role in determining annual mass balance. Development of surpaglacial ponds may be controlled by the magnitudes of surface undulations, meltwater inputs, and the glacier's general surface gradient. These lakes are not necessarily permanent: they enlarge by enhanced ice-cliff ablation, they are advected and deformed by glacial strain, they may disappear due to englacial drainage or prolonged evaporation, and they may not recur in the same locations each year due to changes in surface topography and hydrologic routing. The prevalence and character of such lakes varies greatly throughout the year. In the cold, dry winter (October-March), the debris surface is largely snow-covered and supraglacial lakes are frozen. During the arid premonsoon (April-May), lakes thaw and the debris surface is dry and free of snow. The debris surface becomes nearly-saturated by monsoonal rains (June-September) leading to surface runoff and widespread lake-filling. During this dynamic monsoon period, ponded water substantially alters the glacier's specific energy balance by increasing the effective thermal conductivity between atmosphere and ice, acting as a heat reservoir, and reducing albedo. Additionally, supraglacial ponds often enhance ablation processes in proximal areas by initiating lake-marginal calving and exposing debris-free ice cliffs. Through these processes supraglacial

  3. Building Climate Resilience at NASA Ames Research Center

    Science.gov (United States)

    Iraci, L. T.; Mueller, C.; Podolske, J. R.; Milesi, C.

    2016-12-01

    NASA Ames Research Center, located at the southern end of the San Francisco Bay (SFB) estuary, has identified three primary vulnerabilities to changes in climate. The Ames Climate Adaptation Science Investigator (CASI) workgroup has studied each of these challenges to operations and the potential exposure of infrastructure and employees to an increased frequency of hazards. Sea level rise inundation scenarios for the SFB Area generally refer to projected scenarios in mean sea level rather than changes in extreme tides that could occur during future storm conditions. In the summer of 2014, high resolution 3-D mapping of the low-lying portion of Ames was performed. Those data are integrated with improved sea level inundation scenarios to identify the buildings, basements and drainage systems potentially affected. We will also identify the impacts of sea level and storm surge effects on transportation to and from the Center. This information will help Center management develop future master plans. Climate change will also lead to changes in temperature, storm frequency and intensity. These changes have potential impacts on localized floods and ecosystems, as well as on electricity and water availability. Over the coming decades, these changes will be imposed on top of ongoing land use and land cover changes, especially those deriving from continued urbanization and increase in impervious surface areas. These coupled changes have the potential to create a series of cascading impacts on ecosystems, including changes in primary productivity and disturbance of hydrological properties and increased flood risk. The majority of the electricity used at Ames is supplied by hydroelectric dams, which will be influenced by reductions in precipitation or changes in the timing or phase of precipitation which reduces snow pack. Coupled with increased demand for summertime air conditioning and other cooling needs, NASA Ames is at risk for electricity shortfalls. To assess the

  4. The Role of Paleo-Drought Atlases in Climate Change Research Over the Common Era

    Science.gov (United States)

    Cook, E.

    2010-12-01

    Hydroclimatic variability is a complex spatiotemporal process that requires the generation of long detailed climate field reconstructions to capture its full range of variability over the Common Era. While it is possible to generate these ‘paleo-drought atlases’ from complex multi-proxy arrays of paleoclimate indicators, the greatest success to date has come from simply using dense networks of exactly dated, moisture-sensitive, annual tree-ring chronologies for reconstruction. The ‘North American Drought Atlas’ (NADA) serves as an archetype in this regard. It has been used to identify the occurrence of unprecedented megadroughts over the past millennium in North America and map them out in a form that is useful for climate model experiments. Thus, the NADA has been used with great success in tests of forced and unforced causes of hydroclimatic variability over North America, especially those related to changing sea surface temperatures (SSTs). The NADA archetype has been successfully extended now to Asia in the form of the ‘Monsoon Asia Drought Atlas’ (MADA). Similar to the NADA, the MADA has revealed the occurrence of past megadroughts in areas affected by the Asian monsoon, including ones in the 14th and 15th centuries that are associated with the demise of the Khmer civilization at Angkor located in present day Cambodia. Explicit forced model experiments, similar to those made for comparison with the NADA, have not yet been conducted, but empirical comparisons indicate once again that SSTs are likely to contribute greatly to hydroclimatic variability over Asia. A project to develop an ‘Old World Drought Atlas’ (OWDA) over Europe, North Africa, and Asia Minor is now underway. When completed, it will allow for joint spatiotemporal comparisons to be made between the NADA, MADA, and OWDA over the Common Era and serve as the basis for climate modeling experiments over hemispheric spatial scales.

  5. ARM Climate Research Facility: Outreach Tools and Strategies

    Science.gov (United States)

    Roeder, L.; Jundt, R.

    2009-12-01

    Sponsored by the Department of Energy, the ARM Climate Research Facility is a global scientific user facility for the study of climate change. To publicize progress and achievements and to reach new users, the ACRF uses a variety of Web 2.0 tools and strategies that build off of the program’s comprehensive and well established News Center (www.arm.gov/news). These strategies include: an RSS subscription service for specific news categories; an email “newsletter” distribution to the user community that compiles the latest News Center updates into a short summary with links; and a Facebook page that pulls information from the News Center and links to relevant information in other online venues, including those of our collaborators. The ACRF also interacts with users through field campaign blogs, like Discovery Channel’s EarthLive, to share research experiences from the field. Increasingly, field campaign Wikis are established to help ACRF researchers collaborate during the planning and implementation phases of their field studies and include easy to use logs and image libraries to help record the campaigns. This vital reference information is used in developing outreach material that is shared in highlights, news, and Facebook. Other Web 2.0 tools that ACRF uses include Google Maps to help users visualize facility locations and aircraft flight patterns. Easy-to-use comment boxes are also available on many of the data-related web pages on www.arm.gov to encourage feedback. To provide additional opportunities for increased interaction with the public and user community, future Web 2.0 plans under consideration for ACRF include: evaluating field campaigns for Twitter and microblogging opportunities, adding public discussion forums to research highlight web pages, moving existing photos into albums on FlickR or Facebook, and building online video archives through YouTube.

  6. Climate change and health: Research challenges for health in the developing countries

    Directory of Open Access Journals (Sweden)

    Pandve Harshal

    2010-01-01

    Full Text Available Climate change has emerged as one of the most important environmental issues ever to confront humanity. Recent events have emphatically demonstrated our growing vulnerability to climate change, and health hazards are a major concern. Research pertaining to the effects of climate change on human health is the need of the hour. This paper discusses the broad challenges in health research in developing countries with specific reference to climate change.

  7. The role of architectural research centers in addressing climate change

    Directory of Open Access Journals (Sweden)

    John Carmody

    2012-10-01

    Full Text Available ABSTRACT: It is clear that an urgent, major transformation needs to happen in the design of the built environment to respond to impending climate change and other environmental degradation. This paper will explain the potential role of architectural research centers in this transformation and provide examples from the Center for Sustainable Building Research (CSBR at the University of Minnesota. A research center can become a regional hub to coordinate and disseminate critical information. CSBR is leading the establishment of Architecture 2030 standards in Minnesota, assisting local governments in writing green building policy, providing design assistance to local government, developing tools to assist design decision making, providing technical assistance to the affordable housing community inMinnesota, and establishing a regional case study database that includes actual performance information. CSBR is creating a publicly accessible, credible knowledge base on new approaches, technologies and actual performance outcomes. Research centers such as CSBR can be a critical component of the necessary feedback loop often lacking in the building industry. A research center can also fill major gaps in providing in depth professional education as well as be a catalyst for demonstration projects and public education.

  8. A proposal for a new scenario framework to support research and assessment in different climate research communities

    NARCIS (Netherlands)

    Vuuren, D.P. van; Riahi, K.; Moss, R.; Edmonds, J.; Thomson, A.; Nakicenovic, N.; Kram, T.; Berkhout, F.; Swart, R.; Janetos, A.; Rose, S.K.; Arnell, N.

    2012-01-01

    In this paper, we propose a scenario framework that could provide a scenario " thread" through the different climate research communities (climate change - vulnerability, impact, and adaptation - and mitigation) in order to support assessment of mitigation and adaptation strategies and climate impac

  9. A proposal for a new scenario framework to support research and assessment in different climate research communities

    NARCIS (Netherlands)

    Vuuren, van D.P.; Riahi, K.; Moss, R.; Edmonds, J.; Thomson, A.; Nakicenovic, N.; Kram, T.; Berkhout, F.; Swart, R.J.; Janetos, A.; Rose, S.K.; Arnell, N.

    2012-01-01

    In this paper, we propose a scenario framework that could provide a scenario "thread" through the different climate research communities (climate change - vulnerability, impact, and adaptation - and mitigation) in order to support assessment of mitigation and adaptation strategies and climate impact

  10. The Asian Monsoon Links to Solar Changes and the Intertropical Convergence Zone and 1300 Years of Chinese Human Susceptibility

    Science.gov (United States)

    Yu, E.; Hsu, Y.; Lee, T.

    2011-12-01

    Here we present a new paleoclimatic record from a sediment core recovered in Lake Liyutan in central Taiwan over the last 1300 years. The age model is based on 2 AMS 14C dates. Adjustments of age were using the well-dated records from a near by lake sediment core. The Lake Liyutan sediments record the strength of the summer monsoon in two independent ways: (1) the magnetic parameters (ARM/χ, ARM, anhysteresis remenent magnetization; χ, Volume susceptibility) and magnetic susceptibility, and (2) total organic carbon content, organic C/N elemental ratio and δ13Corg of the sediments as a result of changes in different organic matter origins and terrigenous detritus dilution due to precipitation. All the proxy records are 10 to 30- year-resolution. Weaker summer monsoon phases reconstructed from the Lake Liyutan correlate with higher δ18O at Dongge and Hulu caves, which indicates lower summer precipitation rates. Moreover, it is interesting to find that the strong winter monsoon from the Lake Huguang Maar records show a synchronous relationship with weaker summer monsoon from the caves and the Lake Liyutan. From the coincidence in timing, these records were explained by migrations in the intertropical convergence zone. In addition, the weak Asian summer monsoon in the Lake Liyutan corresponds with lowering Northern Hemisphere summer insolation recorded at Dongge cave. Climate variations influenced the agricultural productivity, health risk, and conflict level of preindustrial societies. We note that, on the basis of our new lake record, major changes in Chinese dynasties occurred when the summer monsoon strength was weaker and rainfall was reduced. The Tang dynasty began to ebb in the eighth century, and it fully collapsed in AD907, then the dynastic transitions to the Five Dynasties and Ten Kingdoms period. The weak summer monsoon and reduced rainfall was indicated in the coincidence in timing of the sediment core LYT-3A from Lake Liyutan during 1100 - 1000BP. In

  11. Patterns and biases in climate change research on amphibians and reptiles: a systematic review.

    Science.gov (United States)

    Winter, Maiken; Fiedler, Wolfgang; Hochachka, Wesley M; Koehncke, Arnulf; Meiri, Shai; De la Riva, Ignacio

    2016-09-01

    Climate change probably has severe impacts on animal populations, but demonstrating a causal link can be difficult because of potential influences by additional factors. Assessing global impacts of climate change effects may also be hampered by narrow taxonomic and geographical research foci. We review studies on the effects of climate change on populations of amphibians and reptiles to assess climate change effects and potential biases associated with the body of work that has been conducted within the last decade. We use data from 104 studies regarding the effect of climate on 313 species, from 464 species-study combinations. Climate change effects were reported in 65% of studies. Climate change was identified as causing population declines or range restrictions in half of the cases. The probability of identifying an effect of climate change varied among regions, taxa and research methods. Climatic effects were equally prevalent in studies exclusively investigating climate factors (more than 50% of studies) and in studies including additional factors, thus bolstering confidence in the results of studies exclusively examining effects of climate change. Our analyses reveal biases with respect to geography, taxonomy and research question, making global conclusions impossible. Additional research should focus on under-represented regions, taxa and questions. Conservation and climate policy should consider the documented harm climate change causes reptiles and amphibians.

  12. Patterns and biases in climate change research on amphibians and reptiles: a systematic review

    Science.gov (United States)

    2016-01-01

    Climate change probably has severe impacts on animal populations, but demonstrating a causal link can be difficult because of potential influences by additional factors. Assessing global impacts of climate change effects may also be hampered by narrow taxonomic and geographical research foci. We review studies on the effects of climate change on populations of amphibians and reptiles to assess climate change effects and potential biases associated with the body of work that has been conducted within the last decade. We use data from 104 studies regarding the effect of climate on 313 species, from 464 species–study combinations. Climate change effects were reported in 65% of studies. Climate change was identified as causing population declines or range restrictions in half of the cases. The probability of identifying an effect of climate change varied among regions, taxa and research methods. Climatic effects were equally prevalent in studies exclusively investigating climate factors (more than 50% of studies) and in studies including additional factors, thus bolstering confidence in the results of studies exclusively examining effects of climate change. Our analyses reveal biases with respect to geography, taxonomy and research question, making global conclusions impossible. Additional research should focus on under-represented regions, taxa and questions. Conservation and climate policy should consider the documented harm climate change causes reptiles and amphibians. PMID:27703684

  13. Improving GEFS Weather Forecasts for Indian Monsoon with Statistical Downscaling

    Science.gov (United States)

    Agrawal, Ankita; Salvi, Kaustubh; Ghosh, Subimal

    2014-05-01

    Weather forecast has always been a challenging research problem, yet of a paramount importance as it serves the role of 'key input' in formulating modus operandi for immediate future. Short range rainfall forecasts influence a wide range of entities, right from agricultural industry to a common man. Accurate forecasts actually help in minimizing the possible damage by implementing pre-decided plan of action and hence it is necessary to gauge the quality of forecasts which might vary with the complexity of weather state and regional parameters. Indian Summer Monsoon Rainfall (ISMR) is one such perfect arena to check the quality of weather forecast not only because of the level of intricacy in spatial and temporal patterns associated with it, but also the amount of damage it can cause (because of poor forecasts) to the Indian economy by affecting agriculture Industry. The present study is undertaken with the rationales of assessing, the ability of Global Ensemble Forecast System (GEFS) in predicting ISMR over central India and the skill of statistical downscaling technique in adding value to the predictions by taking them closer to evidentiary target dataset. GEFS is a global numerical weather prediction system providing the forecast results of different climate variables at a fine resolution (0.5 degree and 1 degree). GEFS shows good skills in predicting different climatic variables but fails miserably over rainfall predictions for Indian summer monsoon rainfall, which is evident from a very low to negative correlation values between predicted and observed rainfall. Towards the fulfilment of second rationale, the statistical relationship is established between the reasonably well predicted climate variables (GEFS) and observed rainfall. The GEFS predictors are treated with multicollinearity and dimensionality reduction techniques, such as principal component analysis (PCA) and least absolute shrinkage and selection operator (LASSO). Statistical relationship is

  14. Comparative Study of Monsoon Rainfall Variability over India and the Odisha State

    Directory of Open Access Journals (Sweden)

    K C Gouda

    2017-10-01

    Full Text Available Indian summer monsoon (ISM plays an important role in the weather and climate system over India. The rainfall during monsoon season controls many sectors from agriculture, food, energy, and water, to the management of disasters. Being a coastal province on the eastern side of India, Odisha is one of the most important states affected by the monsoon rainfall and associated hydro-meteorological systems. The variability of monsoon rainfall is highly unpredictable at multiple scales both in space and time. In this study, the monsoon variability over the state of Odisha is studied using the daily gridded rainfall data from India Meteorological Department (IMD. A comparative analysis of the behaviour of monsoon rainfall at a larger scale (India, regional scale (Odisha, and sub-regional scale (zones of Odisha is carried out in terms of the seasonal cycle of monsoon rainfall and its interannual variability. It is seen that there is no synchronization in the seasonal monsoon category (normal/excess/deficit when analysed over large (India and regional (Odisha scales. The impact of El Niño, La Niña, and the Indian Ocean Dipole (IOD on the monsoon rainfall at both scales (large scale and regional scale is analysed and compared. The results show that the impact is much more for rainfall over India, but it has no such relation with the rainfall over Odisha. It is also observed that there is a positive (negative relation of the IOD with the seasonal monsoon rainfall variability over Odisha (India. The correlation between the IAV of monsoon rainfall between the large scale and regional scale was found to be 0.46 with a phase synchronization of 63%. IAV on a sub-regional scale is also presented.

  15. What drives the global summer monsoon over the past millennium?

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jian [Chinese Academy of Sciences, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Nanjing (China); Wang, Bin [University of Hawaii at Manoa, Department of Meteorology, Honolulu, HI (United States); University of Hawaii at Manoa, International Pacific Research Center, Honolulu, HI (United States); Yim, So-Young; Lee, June-Yi [University of Hawaii at Manoa, International Pacific Research Center, Honolulu, HI (United States); Jhun, Jong-Ghap [Seoul National University, School of Earth and Environmental Sciences/Research Institute of Oceanography, Seoul (Korea, Republic of); Ha, Kyung-Ja [Pusan National University, Division of Earth Environmental System, Busan (Korea, Republic of)

    2012-09-15

    The global summer monsoon precipitation (GSMP) provides a fundamental measure for changes in the annual cycle of the climate system and hydroclimate. We investigate mechanisms governing decadal-centennial variations of the GSMP over the past millennium with a coupled climate model's (ECHO-G) simulation forced by solar-volcanic (SV) radiative forcing and greenhouse gases (GHG) forcing. We show that the leading mode of GSMP is a forced response to external forcing on centennial time scale with a globally uniform change of precipitation across all monsoon regions, whereas the second mode represents internal variability on multi-decadal time scale with regional characteristics. The total amount of GSMP varies in phase with the global mean temperature, indicating that global warming is accompanied by amplification of the annual cycle of the climate system. The northern hemisphere summer monsoon precipitation (NHSMP) responds to GHG forcing more sensitively, while the southern hemisphere summer monsoon precipitation (SHSMP) responds to the SV radiative forcing more sensitively. The NHSMP is enhanced by increased NH land-ocean thermal contrast and NH-minus-SH thermal contrast. On the other hand, the SHSMP is strengthened by enhanced SH subtropical highs and the east-west mass contrast between Southeast Pacific and tropical Indian Ocean. The strength of the GSMP is determined by the factors controlling both the NHSMP and SHSMP. Intensification of GSMP is associated with (a) increased global land-ocean thermal contrast, (b) reinforced east-west mass contrast between Southeast Pacific and tropical Indian Ocean, and (c) enhanced circumglobal SH subtropical highs. The physical mechanisms revealed here will add understanding of future change of the global monsoon. (orig.)

  16. Multi-Site and Multi-Variables Statistical Downscaling Technique in the Monsoon Dominated Region of Pakistan

    Science.gov (United States)

    Khan, Firdos; Pilz, Jürgen

    2016-04-01

    stations. The proposed model will be validated by using the (National Centers for Environmental Prediction / National Center for Atmospheric Research) NCEP/NCAR predictors for the period of 1960-1990 and validated for 1990-2000. To investigate the efficiency of the proposed model, it will be compared with the multivariate multiple regression model and with dynamical downscaling climate models by using different climate indices that describe the frequency, intensity and duration of the variables of interest. KEY WORDS: Climate change, Copula, Monsoon, Quantile regression, Spatio-temporal distribution.

  17. Survey of organizational research climates in three research intensive, doctoral granting universities.

    Science.gov (United States)

    Wells, James A; Thrush, Carol R; Martinson, Brian C; May, Terry A; Stickler, Michelle; Callahan, Eileen C; Klomparens, Karen L

    2014-12-01

    The Survey of Organizational Research Climate (SOuRCe) is a new instrument that assesses dimensions of research integrity climate, including ethical leadership, socialization and communication processes, and policies, procedures, structures, and processes to address risks to research integrity. We present a descriptive analysis to characterize differences on the SOuRCe scales across departments, fields of study, and status categories (faculty, postdoctoral scholars, and graduate students) for 11,455 respondents from three research-intensive universities. Among the seven SOuRCe scales, variance explained by status and fields of study ranged from 7.6% (Advisor-Advisee Relations) to 16.2% (Integrity Norms). Department accounted for greater than 50% of the variance explained for each of the SOuRCe scales, ranging from 52.6% (Regulatory Quality) to 80.3% (Integrity Inhibitors). It is feasible to implement this instrument in large university settings across a broad range of fields, department types, and individual roles within academic units. Published baseline results provide initial data for institutions using the SOuRCe who wish to compare their own research integrity climates.

  18. See-saw relationship of the Holocene East Asian-Australian summer monsoon

    Science.gov (United States)

    Eroglu, Deniz; McRobie, Fiona H.; Ozken, Ibrahim; Stemler, Thomas; Wyrwoll, Karl-Heinz; Breitenbach, Sebastian F. M.; Marwan, Norbert; Kurths, Jürgen

    2016-09-01

    The East Asian-Indonesian-Australian summer monsoon (EAIASM) links the Earth's hemispheres and provides a heat source that drives global circulation. At seasonal and inter-seasonal timescales, the summer monsoon of one hemisphere is linked via outflows from the winter monsoon of the opposing hemisphere. Long-term phase relationships between the East Asian summer monsoon (EASM) and the Indonesian-Australian summer monsoon (IASM) are poorly understood, raising questions of long-term adjustments to future greenhouse-triggered climate change and whether these changes could `lock in' possible IASM and EASM phase relationships in a region dependent on monsoonal rainfall. Here we show that a newly developed nonlinear time series analysis technique allows confident identification of strong versus weak monsoon phases at millennial to sub-centennial timescales. We find a see-saw relationship over the last 9,000 years--with strong and weak monsoons opposingly phased and triggered by solar variations. Our results provide insights into centennial- to millennial-scale relationships within the wider EAIASM regime.

  19. See–saw relationship of the Holocene East Asian–Australian summer monsoon

    Science.gov (United States)

    Eroglu, Deniz; McRobie, Fiona H.; Ozken, Ibrahim; Stemler, Thomas; Wyrwoll, Karl-Heinz; Breitenbach, Sebastian F. M.; Marwan, Norbert; Kurths, Jürgen

    2016-01-01

    The East Asian–Indonesian–Australian summer monsoon (EAIASM) links the Earth's hemispheres and provides a heat source that drives global circulation. At seasonal and inter-seasonal timescales, the summer monsoon of one hemisphere is linked via outflows from the winter monsoon of the opposing hemisphere. Long-term phase relationships between the East Asian summer monsoon (EASM) and the Indonesian–Australian summer monsoon (IASM) are poorly understood, raising questions of long-term adjustments to future greenhouse-triggered climate change and whether these changes could ‘lock in' possible IASM and EASM phase relationships in a region dependent on monsoonal rainfall. Here we show that a newly developed nonlinear time series analysis technique allows confident identification of strong versus weak monsoon phases at millennial to sub-centennial timescales. We find a see–saw relationship over the last 9,000 years—with strong and weak monsoons opposingly phased and triggered by solar variations. Our results provide insights into centennial- to millennial-scale relationships within the wider EAIASM regime. PMID:27666662

  20. See-saw relationship of the Holocene East Asian-Australian summer monsoon.

    Science.gov (United States)

    Eroglu, Deniz; McRobie, Fiona H; Ozken, Ibrahim; Stemler, Thomas; Wyrwoll, Karl-Heinz; Breitenbach, Sebastian F M; Marwan, Norbert; Kurths, Jürgen

    2016-09-26

    The East Asian-Indonesian-Australian summer monsoon (EAIASM) links the Earth's hemispheres and provides a heat source that drives global circulation. At seasonal and inter-seasonal timescales, the summer monsoon of one hemisphere is linked via outflows from the winter monsoon of the opposing hemisphere. Long-term phase relationships between the East Asian summer monsoon (EASM) and the Indonesian-Australian summer monsoon (IASM) are poorly understood, raising questions of long-term adjustments to future greenhouse-triggered climate change and whether these changes could 'lock in' possible IASM and EASM phase relationships in a region dependent on monsoonal rainfall. Here we show that a newly developed nonlinear time series analysis technique allows confident identification of strong versus weak monsoon phases at millennial to sub-centennial timescales. We find a see-saw relationship over the last 9,000 years-with strong and weak monsoons opposingly phased and triggered by solar variations. Our results provide insights into centennial- to millennial-scale relationships within the wider EAIASM regime.

  1. Changes in the in-phase relationship between the Indian and subsequent Australian summer monsoons during the past five decades

    Directory of Open Access Journals (Sweden)

    J.-Y. Yu

    2007-10-01

    Full Text Available This study examines the decadal changes in the in-phase relationship between Indian summer monsoon and the subsequent Australian summer monsoon using observational data from 1950–2005. The in-phase relationship is the tendency for a strong Indian summer monsoon to be followed by a strong Australian summer monsoon and vice versa. It is found that the in-phase relationship was weak during the late 1950s and early 1960s, strengthened to a maximum in the early 1970s just before the 1976/77 Pacific climate shift, then declined until the late 1990s. Pacific SST anomalies are noticed to have strong persistence from boreal to austral summer, providing the memory to connect the Indian and subsequent Australian summer monsoon. The simultaneous correlation between the Pacific SST anomalies and the Indian summer monsoon is always strong. It is the weakening and strengthening of the simultaneous correlation between the Australian summer monsoon and the Pacific SST anomalies that contributes to the decadal variations of the in-phase monsoon relation. This study suggests that the interaction between the Australian monsoon and the Pacific Ocean is crucial to tropical climate variability and has experienced significant changes over the past five decades.

  2. ARM Climate Research Facility Quarterly Value-Added Product Report

    Energy Technology Data Exchange (ETDEWEB)

    Sivaraman, C. [DOE ARM Climate Research Facility, Washington, DC (United States)

    2016-10-01

    The purpose of this report is to provide a concise status update for Value-Added Products (VAPs) implemented by the Atmospheric Radiation Measurement (ARM) Climate Research Facility. The report is divided into the following sections: (1) new VAPs for which development has begun; (2) progress on existing VAPs; (3) future VAPs that have been recently approved; (4) other work that leads to a VAP; (5) top requested VAPs from the ARM Data Archive; and (6) a summary of VAP and data releases to production and evaluation. New information is highlighted in blue text. New information about processed data by the developer is highlighted in red text. The upcoming milestones and dates are highlighted in green.

  3. Advance in Application of Regional Climate Models in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; YAN Minhua; CHEN Panqin; XU Helan

    2008-01-01

    Regional climate models have become the powerful tools for simulating regional climate and its changeprocess and have been widely used in China. Using regional climate models, some research results have been obtainedon the following aspects: 1) the numerical simulation of East Asian monsoon climate, including exceptional monsoonprecipitation, summer precipitation distribution, East Asian circulation, multi-year climate average condition, summerrain belt and so on; 2) the simulation of arid climate of the western China, including thermal effect of the Qing-hai-Tibet Plateau, the plateau precipitation in the Qilian Mountains; and the impacts of greenhouse effects (CO2 dou-bling) upon climate in the western China; and 3) the simulation of the climate effect of underlying surface changes, in-cluding the effect of soil on climate formation, the influence of terrain on precipitation, the effect of regional soil deg-radation on regional climate, the effect of various underlying surfaces on regional climate, the effect of land-sea con-trast on the climate formulation, the influence of snow cover over the plateau regions on the regional climate, the effectof vegetation changes on the regional climate, etc. In the process of application of regional climate models, the prefer-ences of the models are improved so that better simulation results are gotten. At last, some suggestions are made aboutthe application of regional climate models in regional climate research in the future.

  4. Potential modulations of pre-monsoon aerosols during El Niño: impact on Indian summer monsoon

    Science.gov (United States)

    Fadnavis, S.; Roy, Chaitri; Sabin, T. P.; Ayantika, D. C.; Ashok, K.

    2016-11-01

    The potential role of aerosol loading on the Indian summer monsoon rainfall during the El Niño years are examined using satellite-derived observations and a state of the art fully interactive aerosol-chemistry-climate model. The Aerosol Index (AI) from TOMS (1978-2005) and Aerosol Optical Depth (AOD) from MISR spectroradiometer (2000-2010) indicate a higher-than-normal aerosol loading over the Indo-Gangetic plain (IGP) during the pre-monsoon season with a concurrent El Niño. Sensitivity experiments using ECHAM5-HAMMOZ climate model suggests that this enhanced loading of pre-monsoon absorbing aerosols over the Indo-Gangetic plain can reduce the drought during El Niño years by invoking the `Elevated-Heat-Pump' mechanism through an anomalous aerosol-induced warm core in the atmospheric column. This anomalous heating upshot the relative strengthening of the cross-equatorial moisture inflow associated with the monsoon and eventually reduces the severity of drought during El Niño years. The findings are subject to the usual limitations such as the uncertainties in observations, and limited number of El Niño years (during the study period).

  5. Deciphering the desiccation trend of the South Asian monsoon hydroclimate in a warming world

    Science.gov (United States)

    Krishnan, R.; Sabin, T. P.; Vellore, R.; Mujumdar, M.; Sanjay, J.; Goswami, B. N.; Hourdin, F.; Dufresne, J.-L.; Terray, P.

    2016-08-01

    Rising propensity of precipitation extremes and concomitant decline of summer-monsoon rains are amongst the most distinctive hydroclimatic signals that have emerged over South Asia since 1950s. A clear understanding of the underlying causes driving these monsoon hydroclimatic signals has remained elusive. Using a state-of-the-art global climate model with high-resolution zooming over South Asia, we demonstrate that a juxtaposition of regional land-use changes, anthropogenic-aerosol forcing and the rapid warming signal of the equatorial Indian Ocean is crucial to produce the observed monsoon weakening in recent decades. Our findings also show that this monsoonal weakening significantly enhances occurrence of localized intense precipitation events, as compared to the global-warming response. A 21st century climate projection using the same high-resolution model indicates persistent decrease of monsoonal rains and prolongation of soil drying. Critical value-additions from this study include (1) realistic simulation of the mean and long-term historical trends in the Indian monsoon rainfall (2) robust attributions of changes in moderate and heavy precipitation events over Central India (3) a 21st century projection of drying trend of the South Asian monsoon. The present findings have profound bearing on the regional water-security, which is already under severe hydrological-stress.

  6. Roadmap towards justice in urban climate adaptation research

    NARCIS (Netherlands)

    Shi, L.; Chu, E.; Anguelovski, I.; Aylett, A.; Debats, J.; Goh, K.; Schenk, T.; Seto, K.C.; Dodman, D.; Roberts, D.; Roberts, J.T.; VanDeveer, S.D.

    2016-01-01

    The 2015 United Nations Climate Change Conference in Paris (COP21) highlighted the importance of cities to climate action, as well as the unjust burdens borne by the world's most disadvantaged peoples in addressing climate impacts. Few studies have documented the barriers to redressing the drivers o

  7. School Climate: Research, Policy, Practice, and Teacher Education

    Science.gov (United States)

    Cohen, Jonathan; McCabe, Libby; Michelli, Nicholas M.; Pickeral, Terry

    2009-01-01

    Background/Context: Educators have written about and studied school climate for 100 years. School climate refers to the quality and character of school life. School climate is based on patterns of people's experiences of school life and reflects norms, goals, values, interpersonal relationships, teaching and learning practices, and organizational…

  8. Solar Climate Engineering and Intellectual Property : Toward a Research Commons

    NARCIS (Netherlands)

    Reynolds, Jesse; Contreras, Jorge L; Sarnoff, Joshua D

    2017-01-01

    Climate change is one of the greatest challenges confronting society today. Solar climate engineering (SCE) has the potential to reduce climate risks substantially. This controversial technology would make the earth more reflective in order to counteract global warming. The science of SCE is still i

  9. Climate Change and Rural Sociology: Broadening the Research Agenda

    Science.gov (United States)

    Dunlap, Riley E.

    2010-01-01

    Climate change is the preeminent environmental problem of this time, and Joseph Molnar's call for greater attention to it by rural sociologists is both welcome and timely. The agenda he lays out for rural sociology's engagement with climate change, however, seems rather narrow and restrictive. Examining the potential impacts of climate change,…

  10. Progress in Research on Climatic Change in China

    Institute of Scientific and Technical Information of China (English)

    LU Xuedu

    2001-01-01

    @@ Global climatic change caused by human factors has become a major issue of increasing international concern. Climatic change may lead to irreversible change to the climatic system on the global scale, and thus result in immeasurable change to the living environment of mankind.

  11. Designing an Africa-EU research and innovation collaboration platform on climate change

    DEFF Research Database (Denmark)

    Tostensen, Arne; Monteverde Haakonsen, Jan; Hughes, Mike;

    Climate change is arguably the most significant of a set of interconnected global challenges threatening water resources and food security. In particular, the relationship between water resources, food systems and climate change is tightly coupled, and improved food security under climate change...... and ongoing successful research and innovation initiatives. Diverse actors from all over the world—from corporations to governments and citizens—are increasingly recognising the urgent need to address climate change in their respective spheres of influence. This report is intended to contribute to making...... this process more effective by developing a proposition for a platform to strengthen Africa-EU research and innovation collaboration on climate change....

  12. Effects of increased CO{sub 2} levels on monsoons

    Energy Technology Data Exchange (ETDEWEB)

    Cherchi, Annalisa; Masina, Simona; Navarra, Antonio [Centro Euro-Mediterraneo per i Cambiamenti Climatici and Istituto Nazionale di Geofisica e Vulcanologia, Bologna (Italy); Alessandri, Andrea [Centro Euro-Mediterraneo per i Cambiamenti Climatici, Bologna (Italy)

    2011-07-15

    Increased atmospheric carbon dioxide concentration provided warmer atmospheric temperature and higher atmospheric water vapor content, but not necessarily more precipitation. A set of experiments performed with a state-of-the-art coupled general circulation model forced with increased atmospheric CO{sub 2} concentration (2, 4 and 16 times the present-day mean value) were analyzed and compared with a control experiment to evaluate the effect of increased CO{sub 2} levels on monsoons. Generally, the monsoon precipitation responses to CO{sub 2} forcing are largest if extreme concentrations of carbon dioxide are used, but they are not necessarily proportional to the forcing applied. In fact, despite a common response in terms of an atmospheric water vapor increase to the atmospheric warming, two out of the six monsoons studied simulate less or equal summer mean precipitation in the 16 x CO{sub 2} experiment compared to the intermediate sensitivity experiments. The precipitation differences between CO{sub 2} sensitivity experiments and CTRL have been investigated specifying the contribution of thermodynamic and purely dynamic processes. As a general rule, the differences depending on the atmospheric moisture content changes (thermodynamic component) are large and positive, and they tend to be damped by the dynamic component associated with the changes in the vertical velocity. However, differences are observed among monsoons in terms of the role played by other terms (like moisture advection and evaporation) in shaping the precipitation changes in warmer climates. The precipitation increase, even if weak, occurs despite a weakening of the mean circulation in the monsoon regions (''precipitation-wind paradox''). In particular, the tropical east-west Walker circulation is reduced, as found from velocity potential analysis. The meridional component of the monsoon circulation is changed as well, with larger (smaller) meridional (vertical) scales. (orig.)

  13. Instability characteristics of the East Asian Monsoon recorded by high-resolution loess sections from the last interglacial (MIS5)

    Institute of Scientific and Technical Information of China (English)

    GUAN QingYu; PAN BaoTian; GAO HongShan; LI BingYuan; WANG JunPing; SU Huai

    2007-01-01

    The selection of high-resolution loess sections is needed in order to determine the climatic variability of the East Asian Monsoon during the last interglacial. Two sequences of S1 on the eastern and western sides of the Liupan Mountain were both composed of five paleosol layers and four loess layers, indicating that there were five strong summer monsoon events and four strong winter monsoon events in MIS5. This corresponds with other records of the East Asian Monsoon, along with NGRIP and the North Atlantic records, implying that the climate of the Northern Hemisphere was very instable during the last interglacial. Two layers of paleosols and one layer of loess had developed during MIS5a and MIS5c. Compared with MIS5e, the climate in MIS5a and MIS5c fluctuated more intensively on a millennial scale, whereas the climate was relatively stable in MIS5e.

  14. Antarctic link with East Asian summer monsoon variability during the Heinrich Stadial-Bølling interstadial transition

    Science.gov (United States)

    Zhang, Hongbin; Griffiths, Michael L.; Huang, Junhua; Cai, Yanjun; Wang, Canfa; Zhang, Fan; Cheng, Hai; Ning, Youfeng; Hu, Chaoyong; Xie, Shucheng

    2016-11-01

    Previous research has shown a strong persistence for direct teleconnections between the East Asian summer monsoon (EASM) and high northern latitude climate variability during the last glacial and deglaciation, in particular between monsoon weakening and a reduced Atlantic meridional overturning circulation (AMOC). However, less attention has been paid to EASM strengthening as the AMOC was reinvigorated following peak Northern Hemisphere (NH) cooling. Moreover, climate model simulations have suggested a strong role for Antarctic meltwater discharge in modulating northward heat transport and hence NH warming, yet the degree to which Southern Hemisphere (SH) climate anomalies impacted the Asian monsoon region is still unclear. Here we present a new stalagmite oxygen-isotope record from the EASM affected region of central China, which documents two prominent stages of increased 18O-depleted moisture delivery to the region through the transition from Heinrich Stadial 1 (HS1) to the Bølling-Allerød (B-A) interstadial; this is in general agreement with the other monsoonal records from both NH and SH mid to low latitudes. Through novel comparisons with a recent iceberg-rafted debris (IRD) record from the Southern Ocean, we propose that the two-stage EASM intensification observed in our speleothem records were linked with two massive Antarctic icesheet discharge (AID) events at ∼16.0 ka and ∼14.7 ka, immediately following the peak HS1 stadial event. Notably, the large increase in EASM intensity at the beginning of the HS1/B-A transition (∼16 ka) is relatively muted in the NH higher latitudes, and better aligns with the changes observed in the SH, indicating the Antarctic and Southern Ocean perturbations could have an active role in driving the initial EASM strengthening at this time. Indeed, Antarctic freshwater input to the Southern Ocean during these AID events would have cooled the surrounding surface waters and caused an expansion of sea ice, restricting the

  15. Quality Assurance of ARM Program Climate Research Facility Data

    Energy Technology Data Exchange (ETDEWEB)

    Peppler, RA; Kehoe, KE; Sonntag, KL; Bahrmann, CP; Richardson, SJ; Christensen, SW; McCord, RA; Doty, DJ; Wagener, Richard [BNL; Eagan, RC; Lijegren, JC; Orr, BW; Sisterson, DL; Halter, TD; Keck, NN; Long, CN; Macduff, MC; Mather, JH; Perez, RC; Voyles, JW; Ivey, MD; Moore, ST; Nitschke, DL; Perkins, BD; Turner, DD

    2008-03-01

    This report documents key aspects of the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) data quality assurance program as it existed in 2008. The performance of ACRF instruments, sites, and data systems is measured in terms of the availability, usability, and accessibility of the data to a user. First, the data must be available to users; that is, the data must be collected by instrument systems, processed, and delivered to a central repository in a timely manner. Second, the data must be usable; that is, the data must be inspected and deemed of sufficient quality for scientific research purposes, and data users must be able to readily tell where there are known problems in the data. Finally, the data must be accessible; that is, data users must be able to easily find, obtain, and work with the data from the central repository. The processes described in this report include instrument deployment and calibration; instrument and facility maintenance; data collection and processing infrastructure; data stream inspection and assessment; the roles of value-added data processing and field campaigns in specifying data quality and haracterizing the basic measurement; data archival, display, and distribution; data stream reprocessing; and engineering and operations management processes and procedures. Future directions in ACRF data quality assurance also are presented.

  16. Biological and Environmental Research: Climate and Environmental Sciences Division: U.S./European Workshop on Climate Change Challenges and Observations

    Energy Technology Data Exchange (ETDEWEB)

    Mather, James [Pacific Northwest National Laboratory; McCord, Raymond [Oak Ridge National Laboratory; Sisterson, Doug [Argonne National Laboratory; Voyles, Jimmy [Pacific Northwest National Laboratory

    2012-11-08

    The workshop aimed to identify outstanding climate change science questions and the observational strategies for addressing them. The scientific focus was clouds, aerosols, and precipitation, and the required ground- and aerial-based observations. The workshop findings will be useful input for setting priorities within the Department of Energy (DOE) and the participating European centers. This joint workshop was envisioned as the first step in enhancing the collaboration among these climate research activities needed to better serve the science community.

  17. Inverse relation between summer and winter monsoon strength during late Holocene: continental molecular isotopic record from the Indian subcontinent

    Science.gov (United States)

    Sanyal, P.; Basu, S.; Pillai, A.; Singh, P.; Ratnam, J.; Sankaran, M.; Amibili, A.

    2015-12-01

    The Indian monsoon shapes the livelihood of ca. 40% of world's population. Despite dedicated efforts, comprehensive picture of monsoon variability has proved elusive largely due to the absence of long-term qualitative high-resolution record from key climatic zones and variability of monsoon with respect to various forcing mechanisms (e.g., solar insolation) and teleconnections (e.g., El Niño-Southern Oscillation, Indian Ocean Dipole). In this study, high-resolution molecular (n-alkane) isotopic (δD and δ13C ratios) reconstruction of mid-late Holocene (~5.0 cal ka) climate has been undertaken using lacustrine sediments from two climatically sensitive regions; (i) Arid Banni grasslands, western India with dominant moisture source derived from Indian summer monsoon (June-September) and (ii) Semi-arid Ennamangalam lake, south India with significant fraction of rainfall received during winter period (October to December) from Northeast (NE) monsoon. The climate reconstruction from western India based on δDn-alkane values shows prevalence of intensified monsoon until ca. 3 cal ka followed by gradual decrease in the precipitation. In contrast, climate reconstruction from south India is characterized by more negative δDn-alkane (intensified precipitation) values during late Holocene (~2.5 cal ka). The compilation of paleoclimate records shows that the precipitation pattern in Banni region responded linearly to gradually changing insolation and additionally amplified by climate systems like ENSO. However, intensified monsoon in South India shows strengthened NE monsoonal precipitation during late Holocene. The spatial inhomogeneity in the palaeohydrological record can be attributed to the persistence of inverse relationship between summer and winter monsoon. In addition, strong positive correlation between δDn-alkane and δ13Cn-alkane values from both region shows that the relative abundance of C3-C4 plants in the contemporary ecosystems are governed by rainfall

  18. Role of low level flow on the summer monsoon rainfall over the Indian subcontinent during two contrasting monsoon years

    Digital Repository Service at National Institute of Oceanography (India)

    Swapna, P.; RameshKumar, M.R.

    The summer monsoon rainfall over the Indian subcontinent shows 1 large inter-annual variability in three important aspects, namely, the onset date, quantum of monsoon rainfall and the monsoon activity within the monsoon (June - September) period...

  19. Rainfall analysis for Indian monsoon region using the merged rain gauge observations and satellite estimates: Evaluation of monsoon rainfall features

    Indian Academy of Sciences (India)

    S K Roy Bhowmik; Ananda K Das

    2007-06-01

    Objective analysis of daily rainfall at the resolution of 1° grid for the Indian monsoon region has been carried out merging dense land rainfall observations and INSAT derived precipitation estimates. This daily analysis, being based on high dense rain gauge observations was found to be very realistic and able to reproduce detailed features of Indian summer monsoon. The inter-comparison with the observations suggests that the new analysis could distinctly capture characteristic features of the summer monsoon such as north–south oriented belt of heavy rainfall along the Western Ghats with sharp gradient of rainfall between the west coast heavy rain region and the rain shadow region to the east, pockets of heavy rainfall along the location of monsoon trough/low, over the east central parts of the country, over north–east India, along the foothills of Himalayas and over the north Bay of Bengal. When this product was used to assess the quality of other available standard climate products (CMAP and ECMWF reanalysis) at the grid resolution of 2.5°, it was found that the orographic heavy rainfall along Western Ghats of India was poorly identified by them. However, the GPCC analysis (gauge only) at the resolution of 1° grid closely discerns the new analysis. This suggests that there is a need for a higher resolution analysis with adequate rain gauge observations to retain important aspects of the summer monsoon over India. The case studies illustrated show that the daily analysis is able to capture large-scale as well as mesoscale features of monsoon precipitation systems. This study with data of two seasons (2001 and 2003) has shown sufficiently promising results for operational application, particularly for the validation of NWP models.

  20. Transport pathways of peroxyacetyl nitrate in the upper troposphere and lower stratosphere from different monsoon systems during the summer monsoon season

    Directory of Open Access Journals (Sweden)

    S. Fadnavis

    2014-08-01

    Full Text Available The Asian summer monsoon involves complex transport patterns with large scale redistribution of trace gases in the upper troposphere and lower stratosphere (UTLS. We employ the global chemistry–climate model ECHAM5-HAMMOZ in order to evaluate the transport pathways and the contributions of nitrogen oxide reservoir species PAN, NOx, and HNO3 from various monsoon regions, to the UTLS over Southern Asia and vice versa. The model is evaluated with trace gas retrievals from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS-E and aircraft campaigns during the monsoon season (June–September. There are three regions which contribute substantial pollution to the UTLS during the monsoon: the Asian summer monsoon (ASM, the North American Monsoon (NAM and the West African monsoon (WAM. However, penetration due to ASM convection is deeper into the UTLS as compared to NAM and WAM outflow. The circulation in these monsoon regions distributes PAN into the tropical latitude belt in the upper troposphere. Remote transport also occurs in the extratropical upper troposphere where westerly winds drive North American and European pollutants eastward to partly merge with the ASM plume. Strong ASM convection transports these remote and regional pollutants into the lower stratosphere. In the lower stratosphere the injected pollutants are transported westward by easterly winds. The intense convective activity in the monsoon regions is associated with lightning generation and thereby the emission of NOy species. This will affect the distribution of PAN in the UTLS. The estimates of lightning produced PAN, HNO3, NOx and ozone obtained from control and lightning-off simulations shows high percentage changes over the regions of convective transport especially equatorial Africa and America and comparatively less over the ASM. This indicates higher anthropogenic pollution transport from the ASM region into the UTLS.

  1. Inventory of Research on the Impacts of Climate Change

    OpenAIRE

    2004-01-01

    Climate change is one of the greatest threats for the global environment today. Global mean temperature has risen by about 0.6 degrees C during the 20th century, greater than during any other century in the last 1000 years. Subsequently, climate change is likely to have detrimental effects on all global natural and anthropogenic systems. Climate change will have consequences for the structure and function of ecosystems and all the major global biomes. Also agricultural production and producti...

  2. Stable Carbon Isotope Ratios in Atmospheric VOC across the Asian Summer Monsoon Anticyclone obtained during the OMO-ASIA campaign

    Science.gov (United States)

    Krebsbach, Marc; Koppmann, Ralf; Meisehen, Thomas

    2017-04-01

    The automated high volume air sampling system (MIRAH) has been deployed during the atmospheric measurement campaign OMO-ASIA (Oxidation Mechanism Observations) with the German High Altitude - Long-range research aircraft (HALO) in July and August 2015. The intensive measurement period with base stations in Paphos (Cyprus) and Gan (Maldives) focussed on oxidation processes and air pollution chemistry downwind of the South Asia summer monsoon anticyclone, a pivot area critical for air quality and climate change, both regionally and worldwide. The measurement region covered the Eastern Mediterranean region, the Arabian Peninsula, Egypt, and the Arabian Sea. In total 194 air samples were collected on 17 flights in a height region from 3 km up to 15 km. The air samples were analysed for stable carbon isotope ratios in VOC with GC-C-IRMS in the laboratory afterwards. We determined stable carbon isotope ratios and mixing ratios of several aldehydes, ketones, alcohols, and aromatics. The large extent of the investigated area allowed for encountering air masses with different origin, characteristic, and atmospheric processing, e.g. Mediterranean air masses, crossing of polluted filaments and remnants of the Asian monsoon outflow, split of the Asian monsoon anticyclone. In this presentation we will show first results and interpretations supported by HYSPLIT backward trajectories.

  3. Arabian Peninsula-North Pacific Oscillation and its association with the Asian summer monsoon

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Using correlation and EOF analyses on sea level pressure from 57-year NCEP-NCAR reanalysis data, the Arabian Peninsula-North Pacific Oscillation (APNPO) is identified. The APNPO reflects the co-variability between the North Pacific high and South Asian summer monsoon low. This teleconnec- tion pattern is closely related to the Asian summer monsoon. On interannual timescale, it co-varies with both the East Asian summer monsoon (EASM) and South Asian summer monsoon (SASM); on decadal timescale, it co-varies with the EASM: both exhibit two abrupt climate changes in the middle 1960s and the late 1970s respectively. The possible physical process for the connections between the APNPO and Asian summer monsoon is then explored by analyzing the APNPO-related atmospheric circulations. The results show that with a strong APNPO, the Somali Jet, SASM flow, EASM flow, and South Asian high are all enhanced, and an anomalous anticyclone is produced at the upper level over northeast China via a zonal wave train. Meanwhile, the moisture transportation to the Asian monsoon regions is also strengthened in a strong APNPO year, leading to a strong moisture convergence over India and northern China. All these changes of circulations and moisture conditions finally result in an anoma- lous Asian summer monsoon and monsoon rainfall over India and northern China. In addition, the APNPO has a good persistence from spring to summer. The spring APNPO is also significantly corre- lated with Asian summer monsoon variability. The spring APNPO might therefore provide valuable in- formation for the prediction of Asian summer monsoon.

  4. Trace gas transport out of the Indian Summer Monsoon

    Science.gov (United States)

    Tomsche, Laura; Pozzer, Andrea; Zimmermann, Peter; Parchatka, Uwe; Fischer, Horst

    2016-04-01

    The trace gas transport out of the Indian summer monsoon was investigated during the aircraft campaign OMO (Oxidation Mechanism Observations) with the German research aircraft HALO (High Altitude and Long Range Research Aircraft) in July/August 2015. HALO was based at Paphos/Cyprus and also on Gan/Maledives. Flights took place over the Mediterranean Sea, the Arabian Peninsula and the Arabian Sea. In this work the focus is on the distribution of carbon monoxide (CO) and methane (CH4) in the upper troposphere. They were measured with the laser absorption spectrometer TRISTAR on board of HALO. During the Indian summer monsoon strong convection takes place over India and the Bay of Bengal. In this area the population is high accompanied by many emission sources e.g. wetlands and cultivation of rice. Consequently the boundary layer is polluted containing high concentrations of trace gases like methane and carbon monoxide. Due to vertical transport these polluted air masses are lifted to the upper troposphere. Here they circulate with the so called Asian monsoon anticyclone. In the upper troposphere polluted air masses lead to a change in the chemical composition thus influence the chemical processes. Furthermore the anticyclone spreads the polluted air masses over a larger area. Thus the outflow of the anticyclone in the upper troposphere leads to higher concentrations of trace gases over the Arabian Sea, the Arabian Peninsula and also over the eastern part of North Africa and the eastern part of the Mediterranean Sea. During OMO higher concentrations of methane and carbon monoxide were detected at altitudes between 11km and 15km. The highest measured concentrations of carbon monoxide and methane were observed over Oman. The CO concentration in the outflow of the monsoon exceeds background levels by 10-15ppb. However the enhancement in the concentration is not obviously connected to the monsoon due to the natural variability in the troposphere. The enhancement in the

  5. IEK-3 report 2011. Climate-relevant energy research

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    IEK-3 is one of nine sub-institutes within the Institute of Energy and Climate Research at Forschungszentrum Juelich GmbH. IEK-3 aims to conduct research of social, ecological and economic relevance and thus generate groundbreaking results on an international level. This quality of work is achieved through basic research in close coordination with technical development work in relevant scientific and technical fields of expertise. Special significance is attached here to international cooperations with partners from research and industry. By implementing research results in innovative products, procedures and processes in cooperation with industry, IEK-3 hopes to help bridge the gap between science and technology. Cooperation with universities, universities of applied sciences, training departments and training centers is designed to promote opportunities for further education and training. With a staff of approximately 100, IEK-3 concentrates on the basic topics of electrochemistry and process engineering for fuel cells. In an integrated approach, the four key areas worked on in the institute - direct methanol fuel cells, high-temperature polymer electrolyte fuel cells, solid oxide fuel cells and fuel processing systems - are accompanied by systems analysis and theoretical investigations, basic modeling and simulations, and by experimental and theoretical systems evaluations. The information generated in these areas is used to design and verify functional systems. In addition, particular attention is given to the development, configuration and application of special measuring techniques for the structural analysis of membrane electrode assemblies, for flow simulation and visualization, and for the characterization of stacks. The solid oxide fuel cell (SOFC) stack pictured comprises 36 cells, each with an active cell area of 360 cm{sup 2}. The nominal power at a mean cell voltage of 800 mV is approximately 5.5 kW. The stack is operated on natural gas, which is

  6. "Departmental Climate and Student Experiences in Geography Graduate Programs": Research for Enhancing Departments and Graduate Education

    Science.gov (United States)

    Solem, Michael N.; Lee, Jenny; Schlemper, M. Beth

    2011-01-01

    This article reports the authors' research which combined quantitative and qualitative methods to analyze a rather intangible phenomenon of interest to higher education researchers and administrators, that being "departmental climate" (often referred to as "academic climate"). This investigation required the authors to develop a method by which…

  7. Kurt Lewin's Influence on Social Emotional Climate Research in Germany and the United States.

    Science.gov (United States)

    Saldern, Matthias V.

    Believing that an individual's development is strongly influenced by the way the person perceives his or her environment, Kurt Lewin had a strong influence on the theoretical foundations of social-emotional climate research. Lewin's theories may be compared with the following basic theoretical foundations of social climate research: symbolic…

  8. Meteorological results of monsoon-88 Expedition (pre-monsoon period)

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.; Krishnamurthy, L.; Babu, M.T.

    Mean atmospheric circulation, moisture budget and net heat exchange were studied during a pre-monsoon period (18th March to 3rd May, 1988), making use of the data collected on board "Akademik Korolev" in the central equatorial and southern Arabian...

  9. Decadal/Interdecadal Variations of the Ocean Temperature and its Impacts on Climate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Decadal/interdecadal climate variability is an important research focus of the CLIVAR Program and has been paid more attention. Over recent years, a lot of studies in relation to interdecadal climate variations have been also completed by Chinese scientists. This paper presents an overview of some advances in the study of decadal/interdecadal variations of the ocean temperature and its climate impacts,which includes interdecadal climate wariability in China, the interdecadal modes of sea surface temperature (SST) anomalies in the North Pacific, and in particular, the impacts of interdecadal SST variations on the Asian monsoon rainfall. As summarized in this paper, some results have been achieved by using climate diagnostic studies of historical climatic datasets. Two fundamental interdecadal SST variability modes (7-10-years mode and 25-35-years mode) have been identified over the North Pacific associated with different anomalous patterns of atmospheric circulation. The southern Indian Ocean dipole (SIOD) shows a major feature of interdecadal variation, with a positive (negative) phase favoring a weakened (enhanced) Asian summer monsoon in the following summer. It is also found that the China monsoon rainfall exhibits interdecadal variations with more wet (dry) monsoon years in the Yangtze River (South China and North China) before 1976, but vice versa after 1976. The weakened relationship between the Indian summer rainfall and ENSO is a feature of interdecadal variations, suggesting an important role of the interdecadal variation of the SIOD in the climate over the south Asia and southeast Asia. In addition, evidence indicates that the climate shift in the 1960s may be related to the anomalies of the North Atlantic Oscillation (NAO)and North Pacific Oscillation (NPO). Overall, the present research has improved our understanding of the decadal/interdecadal variations of SST and their impacts on the Asian monsoon rainfall. However, the research also highlights a

  10. National programme for weather, climate and atmosphere research. Annual report 1984/85

    CSIR Research Space (South Africa)

    Louw, CW

    1984-12-01

    Full Text Available This report reviews the activities of the National Programme for Weather, Climate and Atmosphere Research (NPWCAR) for 1984/85, highlights the findings and also discusses future developments and general needs regarding research within the framework...

  11. Advances in ocean modeling for climate change research

    Science.gov (United States)

    Holland, William R.; Capotondi, Antonietta; Holland, Marika M.

    1995-07-01

    An adequate understanding of climate variability and the eventual prediction of climate change are among the most urgent and far-reaching efforts of the scientific community. The climate system is in an ever-changing state with vast impact on mankind in all his activities. Both short and long-term aspects of climate variability are of concern, and the unravelling of "natural" variability from "man-induced" climate change is required to prepare for and ameliorate, if possible, the potentially devastating aspects of such change. In terms of scientific effort, the climate community can be thought of as the union of the disciplinary sciences of meteorology, oceanography, sea ice and glaciology, and land surface processes. Since models are based upon mathematical and numerical constructs, mathematics and computer sciences are also directly involved. In addition, some of the problems of man-induced climate change (release of greenhouse gases, the ozone-hole problem, etc.) are basically chemical in nature, and the expertise of the atmospheric and oceanic chemist is also required. In addition, some part of the response to climate perturbations will arise in the biological world, due to upsetting the balance in the great food web that binds communities together on both the land and the sea. Thus, the problems to be solved are extraordinarily complex and require the efforts of many kinds of scientist.

  12. US Agriculture and Climate Change: Perspectives from Recent Research

    OpenAIRE

    Reilly, John M.

    2004-01-01

    Across several projections of climate change in the coming century, total food production in the United States is not found to be at risk. Some regions, however, could experience declining production and profitability due to unfavorable climate, water availability, ecological pressures, or extreme weather events.

  13. Workshop: Improving the Assessment and Valuation of Climate Change Impacts for Policy and Regulatory Analysis: Research on Climate Change Impacts and Associated Economic Damages (part 2)

    Science.gov (United States)

    This is a workshop titled Improving the Assessment and Valuation of Climate Change Impacts for Policy and Regulatory Analysis: Research on Climate Change Impacts and Associated Economic Damages (part 2)

  14. Southwest monsoon changes indicated by oxygen isotope of ostracode shells from sediments in Qinghai Lake since the late Glacial

    Institute of Scientific and Technical Information of China (English)

    LIU XingQi; SHEN Ji; WANG SuMin; WANG YongBo; LIU WeiGuo

    2007-01-01

    The δ18O records of ostracode shells in sediments of core QH-2000 from Qinghai Lake can be used as a better proxy to reflect monsoon changes. Low monsoon precipitation between 17.5 and 11 cal. Ka BP is indicated by positive δ18O values averaging 2.37‰. A fast shift in δ18O from positive at 11 cal. Ka BP to negative at 10 cal. Ka BP indicates sharp increase of monsoon precipitation. An interval of generally high monsoon precipitation is observed between 10 and 6 cal. Ka BP with δ18O values averaging -2.15‰. Decrease of monsoon precipitation between 6 and 2.5 cal. Ka BP is indicated by positive δ18O values. δ18O keeps positive values averaging 3.0‰ between 2.5 and 0 cal. Ka BP suggesting low high monsoon precipitation. The climatic changes indicated by δ18O records of ostracode shells in sediments of core QH-2000 from Qinghai Lake and our broader regional comparison show that the climate in Qinghai Lake since the late Glacial is probably controlled by southwest monsoon other than southeast monsoon.

  15. Climate exposed: tools and methods in climate research; Le climat a decouvert: Outils et methodes en recherche climatique

    Energy Technology Data Exchange (ETDEWEB)

    Jeandel, C.; Mosseri, R.

    2011-07-01

    This collective book benefited from the experience of more than a hundred of contributors who present a wide survey of the methods and tools implemented to study our climate and its future. They show that, in order to tackle the extraordinary complex climate question, a pluri-disciplinary approach is more necessary than ever, at the crossroad of experiment, observation, simulation and theory. What is the greenhouse effect? Is the role of man detectable and how? How can we measure the meltdown of ice caps and glaciers or the rise of sea level? What data allow to describe and model the past climates? How can we proceed to foresee the evolution of climate? These are some of the many questions addressed in this book. (J.S.)

  16. Simulation of the Indian monsoon and its variability during the last millennium

    Directory of Open Access Journals (Sweden)

    S. Polanski

    2013-02-01

    Full Text Available The general circulation model ECHAM5 has been used to simulate the Indian monsoon and its variability during the Medieval Warm Period (MWP; 900–1100 AD, the Little Ice Age (LIA; 1515–1715 AD and for recent climate (REC; 1800–2000 AD. The focus is on the analysis of external drivers and internal feedbacks leading to extreme rainfall events over India from interannual to multidecadal time scale. An evaluation of spatiotemporal monsoon patterns with present-day observation data is in agreement with other state-of-the-art monsoon modeling studies. The simulated monsoon intensity on multidecadal time scale is weakened (enhanced in summer (winter due to colder (warmer SSTs in the Indian Ocean. Variations in solar insolation are the main drivers for these SST anomalies, verified by very strong temporal anticorrelations between Total Solar Irradiance and All-India-Monsoon-Rainfall in summer monsoon months. The external solar forcing is coupled and overlain by internal climate modes of the ocean (ENSO and IOD with asynchronous intensities and lengths of periods.

    In addition, the model simulations have been compared with a relative moisture index derived from paleoclimatic reconstructions based on various proxies and archives in India. In this context, the Lonar record in Central India has been highlighted and evaluated the first time. The simulated relative annual rainfall anomalies in comparison to present-day climate are in agreement (disagreement with the reconstructed moisture index for MWP (LIA climate.

    In order to investigate the interannual monsoon variability with respect to monsoon failures, dry summer monsoon composites for 30-yr-long periods of MWP, LIA and REC have been further analysed. Within dry years of LIA, the summer rainfall over India and surrounding oceans is less than in MWP indicating stronger drying conditions due to a stronger summer solar insolation forcing coupled with variations in ENSO. To quantify the

  17. Strong winter monsoon wind causes surface cooling over India and China in the Late Miocene

    Directory of Open Access Journals (Sweden)

    H. Tang

    2015-01-01

    Full Text Available Modern Asian winter monsoon characterised by the strong northwesterly wind in East Asia and northeasterly wind in South Asia, has a great impact on the surface temperature of the Asian continent. Its outbreak can result in significant cooling of the monsoon region. However, it is still unclear whether such an impact existed and is detectable in the deep past. In this study, we use temperature reconstructions from plant and mammal fossil data together with climate model results to examine the co-evolution of surface temperature and winter monsoon in the Late Miocene (11–5 Ma, when a significant change of the Asian monsoon system occurred. We find that a stronger-than-present winter monsoon wind might have existed in the Late Miocene due to the lower Asian orography, particularly the northern Tibetan Plateau and the mountains north of it. This can lead to a pronounced cooling in southern China and northern India, which counteracts the generally warmer conditions in the Late Miocene compared to present. The Late Miocene strong winter monsoon was characterised by a marked westerly component and primarily caused by a pressure anomaly between the Tibetan Plateau and Northern Eurasia, rather than by the gradient between the Siberian High and the Aleutian Low. As a result, the close association of surface temperature with winter monsoon strength on inter-annual scale as observed at present may not have established in the Late Miocene.

  18. The East Asian subtropical summer monsoon: Recent progress

    Science.gov (United States)

    He, Jinhai; Liu, Boqi

    2016-04-01

    The East Asian subtropical summer monsoon (EASSM) is one component of the East Asian summer monsoon system, and its evolution determines the weather and climate over East China. In the present paper, we firstly demonstrate the formation and advancement of the EASSM rainbelt and its associated circulation and precipitation patterns through reviewing recent studies and our own analysis based on JRA-55 (Japanese 55-yr Reanalysis) data and CMAP (CPC Merged Analysis of Precipitation), GPCP (Global Precipitation Climatology Project), and TRMM (Tropical Rainfall Measuring Mission) precipitation data. The results show that the rainy season of the EASSM starts over the region to the south of the Yangtze River in early April, with the establishment of strong southerly wind in situ. The EASSM rainfall, which is composed of dominant convective and minor stratiform precipitation, is always accompanied by a frontal system and separated from the tropical summer monsoon system. It moves northward following the onset of the South China Sea summer monsoon. Moreover, the role of the land-sea thermal contrast in the formation and maintenance of the EASSM is illustrated, including in particular the effect of the seasonal transition of the zonal land-sea thermal contrast and the influences from the Tibetan Plateau and midlatitudes. In addition, we reveal a possible reason for the subtropical climate difference between East Asia and East America. Finally, the multi-scale variability of the EASSM and its influential factors are summarized to uncover possible reasons for the intraseasonal, interannual, and interdecadal variability of the EASSM and their importance in climate prediction.

  19. Ethical aspects of the mitigation obstruction argument against climate engineering research.

    Science.gov (United States)

    Morrow, David R

    2014-12-28

    Many commentators fear that climate engineering research might lead policy-makers to reduce mitigation efforts. Most of the literature on this so-called 'moral hazard' problem focuses on the prediction that climate engineering research would reduce mitigation efforts. This paper focuses on a related ethical question: Why would it be a bad thing if climate engineering research obstructed mitigation? If climate engineering promises to be effective enough, it might justify some reduction in mitigation. Climate policy portfolios involving sufficiently large or poorly planned reductions in mitigation, however, could lead to an outcome that would be worse than the portfolio that would be chosen in the absence of further climate engineering research. This paper applies three ethical perspectives to describe the kinds of portfolios that would be worse than that 'baseline portfolio'. The literature on climate engineering identifies various mechanisms that might cause policy-makers to choose these inferior portfolios, but it is difficult to know in advance whether the existence of these mechanisms means that climate engineering research really would lead to a worse outcome. In the light of that uncertainty, a precautionary approach suggests that researchers should take measures to reduce the risk of mitigation obstruction. Several such measures are suggested.

  20. The South American Monsoon Variability over the Last Millennium in CMIP5/PMIP3 simulations

    Directory of Open Access Journals (Sweden)

    M. Rojas

    2015-12-01

    Full Text Available In this paper we assess South American Monsoon System (SAMS variability throughout the Last Millennium as depicted by the Coupled Modelling Intercomparison Project version 5/Paleo Modelling Intercomparison Project version 3 (CMIP5/PMIP3 simulations. High-resolution proxy records for the South American monsoon over this period show a coherent regional picture of a weak monsoon during the Medieval Climate Anomaly period and a stronger monsoon during the Little Ice Age (LIA. Due to the small forcing during the past 1000 years, CMIP5/PMIP3 model simulations do not show very strong temperature anomalies over these two specific periods, which in turn do not translate into clear precipitation anomalies, as suggested by rainfall reconstructions in South America. However, with an ad-hoc definition of these two periods for each model simulation, several coherent large-scale atmospheric circulation anomalies were identified. The models feature a stronger Monsoon during the LIA associated with: (i an enhancement of the rising motion in the SAMS domain in austral summer, (ii a stronger monsoon-related upper-troposphere anticyclone, (iii activation of the South American dipole, which results to a certain extent in a poleward shift in the South Atlantic Convergence Zone and (iv a weaker upper-level sub tropical jet over South America, this providing important insights into the mechanisms of these climate anomalies over South America during the past millennium.

  1. Research on Climate Change and Climate Change Communication%论气候变化与气候传播

    Institute of Scientific and Technical Information of China (English)

    郑保卫; 李玉洁

    2011-01-01

    The paper analyses the origin of the climate change, makes discussion about the rising and importance of climate change communication research, introduces the current research of climate change communication both at home and abroad, and clarifies the basic notion and way in the research. It defines the climate change communication as such a commutative activity which promotes the climate change information and related scientific knowledge to be understood and mastered by the public then to seek the solving of climate change problems as the target via changing the public's attitude and behavior regarding the climate change. While the paper also points out the meaning of this research lies in: to make theory summary and systematic explanation of the climate change communication phenomena, to do the mass dissemination and popularization work of such kind of knowledge, and to provide academic supports for those stakeholders including the government ,media ,business and NGO of climate change.%本文论述了气候变化问题的由来及发展,以及气候传播研究的兴起及意义,介绍了国外和国内气候传播研究的现状,同时厘清了气候传播研究中的一些基本概念与思路。论文认为气候传播是将气候变化信息及其相关科学知识为社会与公众所理解和掌握,并通过公众态度和行为的改变,以寻求气候变化问题解决为目标的社会传播活动;指出气候传播研究的目的及意义在于:对气候传播现象进行理论概括和系统阐释;对气候传播知识进行社会传播与推广;为政府、媒体、企业和NGO等社会组织提供有关气候传播的学术支持等。

  2. Carbon Dioxide Effects Research and Assessment Program: Proceedings of the carbon dioxide and climate research program conference

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, L E [ed.

    1980-12-01

    Papers presented at the Carbon Dioxide and Climate Research Program Conference are included in this volume. Topics discussed are: the carbon cycle; modeling the carbon system; climatic response due to increased CO2; climate modeling; the use of paleoclimatic data in understanding climate change; attitudes and implications of CO2; social responses to the CO2 problem; a scenario for atmospheric CO2 to 2025; marine photosynthesis and the global carbon cycle; and the role of tropical forests in the carbon balance of the world. Separate abstracts of nine papers have been prepared for inclusion in the Energy Data Base. (RJC)

  3. 过去3000年季风降水变化与突变事件的洞穴石笋记录对比%Summer monsoon precipitation variations and abrupt climate events during the 3000 years:records from stalagmites in China

    Institute of Scientific and Technical Information of China (English)

    董进国

    2012-01-01

    基于辽宁省暖和洞2支石笋6个230Th年龄与190个δ18O数据,建立了晚全新世3500~200a B.P.东亚季风降水序列。3个百年尺度的弱季风事件已被证实:2800-2600、1500-1200和400-200a B.P.,其与北大西洋冰漂碎屑事件在发生时间上具有较好的一致性。与内陆高精度、高分辨率石笋δ18O记录对比结果显示:1)轨道-千年尺度季风降水长期趋势变化相一致;2)百年-数十年尺度上季风降水具有明显的区域性,如距今1200-500 a B.P.,东北地区降水逐渐增加,西部干旱-半干旱地区降水逐渐减少,长江中下游以及南方地区降水变化趋势不明显。太阳活动与北大西洋气候波动可能对百年尺度东亚夏季风的强弱变化施加了重要影响。%We developed a composite oxygen isotopic record of cave calcite for the last 3500 years based on two stalagmites from the Nuanhe Cave in eastern Liaoning province,northeastern China. Replication of the stalagmite δ18O from several caves in all contemporaneous growth intervals shows the kinetic fractionation was negligible and the δ18O shifts were primarily caused by regional climate change.We interpreted our record in terms of meteoric precipitation changes,hence the variability of East Asian Monsoon intensity.Three internals of low precipitation were inferred in 2800-2600 y B.P.,1500-1200y B.P.and 400-200 y B.P.,which correlated well with North Atlantic drift ice events.A comparison with other high-resolution and high-precise speleothem records from different climate regions indicates:(1) On orbital-millennial scale it indeed displayed similar long-trend change of monsoon precipitation.(2) However,regional differences in monsoon precipitation occurred along the latitudinal transect from 25°N to 41°N on centennial-to decadal-scale.For example,summer monsoon precipitation in the northeastern and northern China increased gradually during the 9-16th centuries,and oppose trends were found in arid

  4. The french researches on the climatic change; Les recherches francaises sur le changement climatique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Scientists were the first to prevent decision makers on the risk of the climatic change bond to the greenhouse gases emissions. The results of the third GIEC report confirmed that the main part of the global warming of the last 50 years is due to the human activities. This document presents the major results of the french researches during the last five years: the planet observation, the climate evolution study, the simulation of the future climate, the climatic change in France, the impacts of the climatic change on the marine and earth biosphere, the climatic risks and the public policies, the health impacts, the 2003 heat and the research infrastructures. (A.L.B.)

  5. Transport pathways of peroxyacetyl nitrate in the upper troposphere and lower stratosphere from different monsoon systems during the summer monsoon season

    Directory of Open Access Journals (Sweden)

    S. Fadnavis

    2015-06-01

    Full Text Available The Asian summer monsoon involves complex transport patterns with large scale redistribution of trace gases in the upper troposphere and lower stratosphere (UTLS. We employ the global chemistry-climate model ECHAM5-HAMMOZ in order to evaluate the transport pathways and the contributions of nitrogen oxide species PAN, NOx, and HNO3 from various monsoon regions, to the UTLS over Southern Asia and vice versa. Simulated long term seasonal mean mixing ratios are compared with trace gas retrievals from the Michelson Interferometer for Passive Atmospheric Sounding aboard ENVISAT(MIPAS-E and aircraft campaigns during the monsoon season (June–September in order to evaluate the model's ability to reproduce these transport patterns. The model simulations show that there are three regions which contribute substantial pollution to the South Asian UTLS: the Asian summer monsoon (ASM, the North American Monsoon (NAM and the West African monsoon (WAM. However, penetration due to ASM convection reaches deeper into the UTLS as compared to NAM and WAM outflow. The circulation in all three monsoon regions distributes PAN into the tropical latitude belt in the upper troposphere. Remote transport also occurs in the extratropical upper troposphere where westerly winds drive North American and European pollutants eastward where they can become part of the ASM convection and be lifted into the lower stratosphere. In the lower stratosphere the injected pollutants are transported westward by easterly winds. The intense convective activity in the monsoon regions is associated with lightning and thereby the formation of additional NOx. This also affects the distribution of PAN in the UTLS. According to sensitivity simulations with and without lightning, increase in concentrations of PAN (~ 40%, HNO3 (75%, NOx (70% and ozone (30% over the regions of convective transport, especially over equatorial Africa and America and comparatively less over the ASM. This indicates that

  6. The Dynamic Plateau Monsoon Index and Its Association with General Circulation Anomalies

    Institute of Scientific and Technical Information of China (English)

    XUN Xueyi; HU Zeyong; MA Yaoming

    2012-01-01

    Based on monthly ECMWF reanalysis-Interim (ERA-Interim) reanalysis data,along with monthly precipitation and temperature data,the Dynamic Plateau Monsoon Index (DPMI) is defined.The results of a contrast analysis of the DPMI versus the Traditional Plateau Monsoon Index (TPMI) are described.The response of general circulation to northern Qinghai-Xizang Plateau summer monsoon anomalies and the correlation of the DPMI with general circulation anomalies are investigated.The results show that,the DPMI reflected meteorological elements better and depicted climate variation more accurately than the TPMI.In years when the plateau summer monsoon is strong,the low over the plateau and the trough near the eastern coast of Asia are deeper and higher than normal over South China.This correlation corresponds to two anomalous cyclones over the plateau and the eastern coast of Asia and an anomalous anticyclone in South China.The plateau and its adjacent regions are affected by anomalous southwesterly winds that transport more moisture to South China and cause more precipitation.The lower reaches of the Yangtze River appear to receive more precipitation by means of the strong westerly water vapor flow transported from the "large triangle affecting the region".In years when the plateau summer monsoon is weak,these are opposite.The plateau monsoon is closely related to the intensity and position of the South Asian high,and the existence of a teleconnection pattern in the mid-upper levels suggests a possible linl~ge of the East Asian monsoon and the Indian monsoon to the plateau summer monsoon.

  7. Dominating Controls for Wetter South Asian Summer Monsoon in the Twenty-First Century

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Rui; Ashfaq, Moetasim; Rastogi, Deeksha; Leung, Lai-Yung R.; Dominguez, Francina

    2015-04-01

    We analyze a suite of Global Climate Models from the 5th Phase of Coupled Models Intercomparison Project (CMIP5) archives to understand the mechanisms behind a net increase in the South Asian summer monsoon precipitation in response to enhanced radiative forcing during the 21st century despite a robust weakening of dynamics governing the monsoon circulation. Combining the future changes in the contributions from various sources, which contribute to the moisture supply over South Asia, with those in monsoon dynamics and atmospheric moisture content, we establish a pathway of understanding that partly explains these counteracting responses to increase in radiative forcing. Our analysis suggests that both regional (local recycling, Arabian Sea, Bay of Bengal) and remote (mainly Indian Ocean) sources contribute to the moisture supply for precipitation over South Asia during the summer season that is facilitated by the monsoon dynamics. Increase in radiative forcing fuels an increase in the atmospheric moisture content through warmer temperatures. For regional moisture sources, the effect of excessive atmospheric moisture is offset by weaker monsoon circulation and uncertainty in the response of the evapotranspiration over land, so anomalies in their contribution to the total moisture supply are either mixed or muted. In contrast, weakening of the monsoon dynamics has less influence on the moisture supply from remote sources that not only is a dominant moisture contributor in the historical period, but is also the net driver of the positive summer monsoon precipitation response in the 21st century. Our results also indicate that historic measures of the monsoon dynamics may not be well suited to predict the non-stationary moisture driven South Asian summer monsoon precipitation response in the 21st century.

  8. Perceptions of climate change in China:The research and policy connection

    Institute of Scientific and Technical Information of China (English)

    LiHua Zhou; J Scott Hauger; Ning Liu; HuiLing Lu

    2014-01-01

    Global climate change has evolved from a scientific problem into an economic and political problem of worldwide inter-est. National perspectives play a crucial role in addressing climate change. Mutual understanding of perspectives is nec-essary to result in rational policies and a consensus among stakeholders with divergent interests. Conceptual frameworks for understanding the problem of climate change in China, the largest developing country and the largest greenhouse gas emitter, are of great significance to national and international efforts to address the problems of climate change. Chinese perceptions of climate change as a sustainable development problem have recently been in tension with an emerging Western perspective that frames climate change as a security issue. This paper explores Chinese perceptions of climate change as expressed in recent governmental policy statements, public opinion surveys, and academic scholarship with a focus on publications in Chinese-language journals, often unfamiliar in the West. It looks at the relationship between Chinese research and policy and finds that the Chinese policy frame of climate change as a sustainable development problem draws from the body of domestic research and is reflective of the perspectives and multidisciplinary approach of Chinese researchers in areas of climate change.

  9. Cyclone trends constrain monsoon variability during Late Oligocene sea level highstands (Kachchh Basin, NW India

    Directory of Open Access Journals (Sweden)

    M. Reuter

    2013-01-01

    Full Text Available Important concerns about the consequences of climate change for India are the potential impact on tropical cyclones and the monsoon. Herein we present a sequence of fossil shell beds from the shallow-marine Maniyara Fort Formation (Kachcch Basin as an indicator of tropical cyclone activity along the NW Indian coast during the Late Oligocene warming period (~27–24 Ma. Direct proxies providing information about the atmospheric circulation dynamics over the Indian subcontinent at this time are important since it corresponds to a major climate reorganization in Asia that ends up with the establishment of the modern Asian monsoon system in the Early Miocene. The vast shell concentrations comprise a mixture of parautochthonous and allochthonous assemblages indicating storm-generated sediment transport from deep to shallow water during third-order sea level highstands. Three distinct skeletal assemblages were distinguished each recording a relative storm wave base depth. (1 A shallow storm wave base is shown by nearshore mollusks, corals and Clypeaster echinoids; (2 an intermediate storm wave base depth is indicated by lepidocyclind foraminifers, Eupatagus echinoids and corallinaceans; and (3 a deep storm wave base is represented by an Amussiopecten–Schizaster echinoid assemblage. Vertical changes in these skeletal associations give evidence of gradually increasing tropical cyclone intensity in line with third-order sea level rise. The intensity of cyclones over the Arabian Sea is primarily linked to the strength of the Indian monsoon. Therefore and since the topographic boundary conditions for the Indian monsoon already existed in the Late Oligocene, the longer-term cyclone trends were interpreted to reflect monsoon variability during the initiation of the Asian monsoon system. Our results imply an active monsoon over the Eastern Tethys at ~26 Ma followed by a period of monsoon weakening during the peak of the Late Oligocene

  10. Cyclone trends constrain monsoon variability during late Oligocene sea level highstands (Kachchh Basin, NW India)

    Science.gov (United States)

    Reuter, M.; Piller, W. E.; Harzhauser, M.; Kroh, A.

    2013-09-01

    Climate change has an unknown impact on tropical cyclones and the Asian monsoon. Herein we present a sequence of fossil shell beds from the shallow-marine Maniyara Fort Formation (Kachcch Basin) as a recorder of tropical cyclone activity along the NW Indian coast during the late Oligocene warming period (~ 27-24 Ma). Proxy data providing information about the atmospheric circulation dynamics over the Indian subcontinent at this time are important since it corresponds to a major climate reorganization in Asia that ends up with the establishment of the modern Asian monsoon system at the Oligocene-Miocene boundary. The vast shell concentrations are comprised of a mixture of parautochthonous and allochthonous assemblages indicating storm-generated sediment transport from deeper to shallow water during third-order sea level highstands. Three distinct skeletal assemblages were distinguished, each recording a relative storm wave base. (1) A shallow storm wave base is shown by nearshore molluscs, reef corals and Clypeaster echinoids; (2) an intermediate storm wave base depth is indicated by lepidocyclinid foraminifers, Eupatagus echinoids and corallinacean algae; and (3) a deep storm wave base is represented by an Amussiopecten bivalve-Schizaster echinoid assemblage. These wave base depth estimates were used for the reconstruction of long-term tropical storm intensity during the late Oligocene. The development and intensification of cyclones over the recent Arabian Sea is primarily limited by the atmospheric monsoon circulation and strength of the associated vertical wind shear. Therefore, since the topographic boundary conditions for the Indian monsoon already existed in the late Oligocene, the reconstructed long-term cyclone trends were interpreted to reflect monsoon variability during the initiation of the Asian monsoon system. Our results imply an active monsoon over the Eastern Tethys at ~ 26 Ma followed by a period of monsoon weakening during the peak of the late

  11. Cyclone trends constrain monsoon variability during late Oligocene sea level highstands (Kachchh Basin, NW India

    Directory of Open Access Journals (Sweden)

    M. Reuter

    2013-09-01

    Full Text Available Climate change has an unknown impact on tropical cyclones and the Asian monsoon. Herein we present a sequence of fossil shell beds from the shallow-marine Maniyara Fort Formation (Kachcch Basin as a recorder of tropical cyclone activity along the NW Indian coast during the late Oligocene warming period (~ 27–24 Ma. Proxy data providing information about the atmospheric circulation dynamics over the Indian subcontinent at this time are important since it corresponds to a major climate reorganization in Asia that ends up with the establishment of the modern Asian monsoon system at the Oligocene–Miocene boundary. The vast shell concentrations are comprised of a mixture of parautochthonous and allochthonous assemblages indicating storm-generated sediment transport from deeper to shallow water during third-order sea level highstands. Three distinct skeletal assemblages were distinguished, each recording a relative storm wave base. (1 A shallow storm wave base is shown by nearshore molluscs, reef corals and Clypeaster echinoids; (2 an intermediate storm wave base depth is indicated by lepidocyclinid foraminifers, Eupatagus echinoids and corallinacean algae; and (3 a deep storm wave base is represented by an Amussiopecten bivalve-Schizaster echinoid assemblage. These wave base depth estimates were used for the reconstruction of long-term tropical storm intensity during the late Oligocene. The development and intensification of cyclones over the recent Arabian Sea is primarily limited by the atmospheric monsoon circulation and strength of the associated vertical wind shear. Therefore, since the topographic boundary conditions for the Indian monsoon already existed in the late Oligocene, the reconstructed long-term cyclone trends were interpreted to reflect monsoon variability during the initiation of the Asian monsoon system. Our results imply an active monsoon over the Eastern Tethys at ~ 26 Ma followed by a period of monsoon weakening during the

  12. Seasonally asymmetric transition of the Asian monsoon in response to ice age boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Hiroaki; Kuroki, Harumitsu; Kamae, Youichi [University of Tsukuba, Graduate School of Life and Environmental Sciences, Tsukuba, Ibaraki (Japan); Ohba, Masamichi [Central Research Institute of Electric Power Industry, Environmental Science Research Laboratory, Abiko (Japan)

    2011-12-15

    Modulation of a monsoon under glacial forcing is examined using an atmosphere-ocean coupled general circulation model (AOGCM) following the specifications established by Paleoclimate Modelling Intercomparison Project phase 2 (PMIP2) to understand the air-sea-land interaction under different climate forcing. Several sensitivity experiments are performed in response to individual changes in the continental ice sheet, orbital parameters, and sea surface temperature (SST) in the Last Glacial Maximum (LGM: 21 ka) to evaluate the driving mechanisms for the anomalous seasonal evolution of the monsoon. Comparison of the model results in the LGM with the pre-industrial (PI) simulation shows that the Arabian Sea and Bay of Bengal are characterized by enhancement of pre-monsoon convection despite a drop in the SST encompassing the globe, while the rainfall is considerably suppressed in the subsequent monsoon period. In the LGM winter relative to the PI, anomalies in the meridional temperature gradient (MTG) between the Asian continents minus the tropical oceans become positive and are consistent with the intensified pre-monsoon circulation. The enhanced MTG anomalies can be explained by a decrease in the condensation heating relevant to the suppressed tropical convection as well as positive insolation anomalies in the higher latitude, showing an opposing view to a warmer future climate. It is also evident that a latitudinal gradient in the SST across the equator plays an important role in the enhancement of pre-monsoon rainfall. As for the summer, the sensitivity experiments imply that two ice sheets over the northern hemisphere cools the air temperature over the Asian continent, which is consistent with the reduction of MTG involved in the attenuated monsoon. The surplus pre-monsoon convection causes a decrease in the SST through increased heat loss from the ocean surface; in other words, negative ocean feedback is also responsible for the subsequent weakening of summer

  13. Evaluation of CFSV2 Forecast Skill for Indian Summer Monsoon Sub-Seasonal Characteristics

    Science.gov (United States)

    S, S. A.; Ghosh, S.

    2015-12-01

    Prediction of sub seasonal monsoon characteristics of Indian Summer Monsoon (ISM) is highly crucial for agricultural planning and water resource management. The Climate forecast System version 2 (CFS V2), the state of the art coupled climate model developed by NCEP, is currently being employed for the seasonal and extended range forecasts of ISM. Even though CFSV2 is a fully coupled ocean- atmosphere- land model with advanced physics, increased resolution and refined initialisation, its ISM forecasts, in terms of seasonal mean and variability needs improvement. Numerous works have been done for verifying the CFSV2 forecasts in terms of the seasonal mean, its mean and variability, active and break spells, and El Nino Southern Oscillation (ENSO) - monsoon interactions. Most of these works are based on either rain fall strength or rainfall based indices. Here we evaluate the skill of CFS v2 model in forecasting the various sub seasonal features of ISM, viz., the onset and withdrawal days of monsoon that are determined using circulation based indices, the Monsoon Intra Seasonal Oscillations (MISO), and Indian Ocean and Pacific Ocean sea surface temperatures. The MISO index, we use here, is based on zonal wind at 850 hPa and Outgoing Long wave Radiation (OLR) anomalies. With this work, we aim at assessing the skill of the model in simulating the large scale circulation patterns and their variabilities within the monsoon season. Variabilities in these large scale circulation patterns are primarily responsible for the variabilities in the seasonal monsoon strength and its temporal distribution across the season. We find that the model can better forecast the large scale circulation and than the actual precipitation. Hence we suggest that seasonal rainfall forecasts can be improved by the statistical downscaling of CFSV2 forecasts by incorporating the established relationships between the well forecasted large scale variables and monsoon precipitation.

  14. Research for assessment, not deployment, of Climate Engineering: The German Research Foundation's Priority Program SPP 1689

    Science.gov (United States)

    Oschlies, Andreas; Klepper, Gernot

    2017-01-01

    The historical developments are reviewed that have led from a bottom-up responsibility initiative of concerned scientists to the emergence of a nationwide interdisciplinary Priority Program on the assessment of Climate Engineering (CE) funded by the German Research Foundation (DFG). Given the perceived lack of comprehensive and comparative appraisals of different CE methods, the Priority Program was designed to encompass both solar radiation management (SRM) and carbon dioxide removal (CDR) ideas and to cover the atmospheric, terrestrial, and oceanic realm. First, key findings obtained by the ongoing Priority Program are summarized and reveal that, compared to earlier assessments such as the 2009 Royal Society report, more detailed investigations tend to indicate less efficiency, lower effectiveness, and often lower safety. Emerging research trends are discussed in the context of the recent Paris agreement to limit global warming to less than two degrees and the associated increasing reliance on negative emission technologies. Our results show then when deployed at scales large enough to have a significant impact on atmospheric CO2, even CDR methods such as afforestation—often perceived as "benign"—can have substantial side effects and may raise severe ethical, legal, and governance issues. We suppose that before being deployed at climatically relevant scales, any negative emission or CE method will require careful analysis of efficiency, effectiveness, and undesired side effects.

  15. Climate Research by K-12 Students: Can They Do It? Will Anybody Care?

    Science.gov (United States)

    Brooks, D. R.

    2011-12-01

    Starting from the premise that engaging students in authentic science research is an activity that benefits science education in general, it is first necessary to consider whether students, in collaboration with teachers and climate scientists, can do climate-related research that actually has scientific value. A workshop held in November 2010, co-sponsored by NSF and NOAA, addressed this question. It took as its starting point this "scientific interest" test: "If students conduct a climate-related research project according to protocols designed in collaboration with climate scientists, when they get done, will any of those scientists care whether they did it or not?" If the answer to this question is "yes," then the project may constitute authentic research, but if the answer is "no," then the project may have educational value, but it is not research. This test is important because only when climate scientists (and other stakeholders interested in climate and climate change) are invested in the outcomes of student research will meaningful student research programs with sustainable support be forthcoming. The absence of climate-related projects in high-level student science fair competitions indicates that, currently, the investment and infrastructure required to support student climate research is lacking. As a result, climate science is losing the battle for the "hearts and minds" of today's best students. The critical task for student climate research is to define projects that are theoretically and practically accessible. This excludes the "big questions" of climate science, such as "Is Earth getting warmer?", but includes many observationally based projects that can help to refine our understanding of climate and climate change. The characteristics of collaborative climate research with students include: 1. carefully drawn distinctions between inquiry-based "learning about" activities and actual research; 2. an identified audience of potential stakeholders

  16. Bringing New Ph.D.s Together for Interdisciplinary Climate Change Research

    Science.gov (United States)

    Phelan, Liam; Jones, Holly; Marlon, Jennifer R.

    2013-01-01

    Climate change is complex and thus requires interdisciplinary research, and new scholars are rising to that challenge. The Dissertations Initiative for the Advancement of Climate Change Research (DISCCRS (pronounced "discourse"); see http://www.disccrs.org) brings together select groups of recent PhD graduates to encourage interdisciplinary work on climate change. The DISCCRS Symposium VII held just outside of Colorado Springs, Colo., brought together 33 graduates from fields as diverse as climatology, ecology, anthropology, and political science for an intensive week of cross-disciplinary engagement in activities like facilitation and leadership training, collaborative research development, peer networking, communication training, and analysis of working group processes.

  17. New frontiers: Exploring climate and health research opportunities for the geoscience community

    Science.gov (United States)

    Colwell, R. R.; Lipschultz, F.; Deangelo, B.

    2016-12-01

    The United States Global Change Research Program's report, "The Impacts of Climate Change on Human Health: A Scientific Assessment" captures the state of the science on impacts, and provides insights into future research opportunities. In particular, the report highlighted a compelling need to improve integrated climate modeling for health impacts, which is often impeded by the complex relationship between climate variability and adverse health outcomes. Closing these gaps is critical to responding to current and future health threats. This presentation will conclude the session by highlighting ways in which the geoscience community can increase its engagement with health sciences to overcome data limitations and further research.

  18. Reconstruction of Last Glacial to early Holocene monsoon variability from relict lake sediments of the Higher Central Himalaya, Uttrakhand, India

    DEFF Research Database (Denmark)

    Juyal, N.; Pant, R.K.; Basavaiah, N.

    2009-01-01

    Proglacial lake sediments at Goting in the Higher Central Himalaya were analyzed to reconstruct the summer monsoon variability during the Last Glacial to early Holocene. Sedimentary structures, high resolution mineral magnetic and geochemical data suggest that the lacustrine environment experienced...... fluctuating monsoonal conditions. Optically stimulated luminescence (OSL) dating indicates that the lake sedimentation occurred before 25 ka and continued after 13 ka. During this period, Goting basin witnessed moderate to strengthened monsoon conditions around 25 ka, 23.5 ka–22.5 ka, 22 ka–18 ka, 17 ka–16...... correspondence at the millennial scale between our data and that of continental and marine records from the Indian sub-continent suggests that Goting basin responded to periods of strengthened monsoon during the Last Glacial to early Holocene. We attribute the millennial scale monsoon variability to climatic...

  19. Monsoon oscillations regulate fertility of the Red Sea

    KAUST Repository

    Raitsos, Dionysios E.

    2015-02-16

    Tropical ocean ecosystems are predicted to become warmer, more saline, and less fertile in a future Earth. The Red Sea, one of the warmest and most saline environments in the world, may afford insights into the function of the tropical ocean ecosystem in a changing planet. We show that the concentration of chlorophyll and the duration of the phytoplankton growing season in the Red Sea are controlled by the strength of the winter Arabian monsoon (through horizontal advection of fertile waters from the Indian Ocean). Furthermore, and contrary to expectation, in the last decade (1998-2010) the winter Red Sea phytoplankton biomass has increased by 75% during prolonged positive phases of the Multivariate El Niño-Southern Oscillation Index. A new mechanism is reported, revealing the synergy of monsoon and climate in regulating Red Sea greenness. © 2015 The Authors.

  20. Adaptation of forest ecosystems to air pollution and climate change: a global assessment on research priorities

    Science.gov (United States)

    Y. Serengil; A. Augustaitis; Andrzej Bytnerowicz; Nancy Grulke; A.R. Kozovitz; R. Matyssek; G. Müller-Starck; M. Schaub; G. Wieser; A.A. Coskun; E. Paoletti

    2011-01-01

    Climate change and air pollution are two of the anthropogenic stressors that require international collaboration. Influence mechanisms and combating strategies towards them have similarities to some extent. Impacts of air pollution and climate change have long been studied under IUFRO Research Group 7.01 and state of the art findings are presented at biannual meetings...