Evaluation of monsoon seasonality and the tropospheric biennial oscillation transitions in the CMIP models

Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 39 (2012): L20713, doi:10.1029/2012GL053322.Characteristics of the Indian and Australian summer monsoon systems, their seasonality and interactions are examined in a variety of observational datasets and in the Coupled Model Intercomparison Project Phase 3 and 5 (CMIP3 and CMIP5) climate models. In particular, it is examined whether preferred monsoon transitions between the two regions and from one year to another, that form parts of the Tropospheric Biennial Oscillation, can lead to improved predictive skill. An overall improvement in simulation of seasonality for both monsoons is seen in CMIP5 over CMIP3, with most CMIP5 models correctly simulating very low rainfall rates outside of the monsoon season. The predictability resulting from each transition is quantified using a Monte Carlo technique. The transition from strong/weak Indian monsoon to strong/weak Australian monsoon shows ∼15% enhanced predictability in the observations, in estimating whether the following monsoon will be stronger/weaker than the climatology. Most models also successfully simulate this transition. However, enhanced predictability for other transitions is less clear.This project was supported by funding from the Australian Research Council (DP110100601) and the Centre of Excellence for Climate System Science. This work was also supported by an award under the Merit Allocation Scheme on the NCI National Facility at the ANU2013-04-2

Functional food-related bioactive compounds: effect of sorghum phenolics on cancer cells in vivo and conversion of short- to long-chain omega-3 polyunsaturated fatty acids in duck liver in vivo

Doctor of PhilosophyDepartment of Human NutritionWeiqun WangMany functional food related bioactive compounds have been discovered and draw the attention of scientists. This dissertation focused on sorghum phenolic compounds and omega-3 polyunsaturated fatty acids. Study 1: phenolic agents in plant foods have been associated with chronic disease prevention, especially cancer. However, a direct evidence and the underlying mechanisms are mostly unknown. This study selected 13 sorghum accessions and was aim to investigate: (1) the effect of extracted sorghum phenolics on inhibiting cancer cell growth using hepatocarcinoma HepG2 and colorectal adenocarcinoma Caco-2 cell lines; (2) and the underlying mechanisms regarding cytotoxicity, cell cycle interruption, and apoptosis induction. Treatment of HepG2 and Caco-2 cells with the extracted phenolics at 0-200 M GAE (Gallic acid equivalent) up to 72 hrs resulted in a dose- and time-dependent reduction in cell number. The underlying mechanism of cell growth inhibition was examined by flow cytometry, significant inverse correlations were observed between the decreased cell number and increased cell cycle arrest at G2/M or induced apoptosis cells in both HepG2 and Caco-2 cells. The cytotoxic assay showed that the sorghum phenolic extracts were non-toxic. Although it was less sensitive, a similar inhibitory impact and underlying mechanisms were found in Caco-2 cells. These results indicated for the 1st time that a direct inhibition of either HepG2 or Caco-2 cell growth by phenolic extracts from13 selected sorghum accessions was due to cytostatic and apoptotic but not cytotoxic mechanisms. In addition, these findings suggested that sorghum be a valuable functional food by providing sustainable phenolics for potential cancer prevention. Study 2: omega-3 polyunsaturated fatty acids (ω-3 PUFAs) especially long-chain ω-3 PUFAs, have been associated with potential health benefits in chronic disease prevention. However, the conversion rate from short- to long-chain ω-3 PUFAs is limited in human body. This study was aim to assess the modification of fatty acid profiles as well as investigate the conversion of short- to long-chain ω-3 PUFAs in the liver of Shan Partridge duck after feeding various dietary fats. The experimental diets substituted the basal diet by 2% of flaxseed oil, rapeseed oil, beef tallow, or fish oil, respectively. As expected, the total ω-3 fatty acids and the ratio of total ω-3/ ω-6 significantly increased in both flaxseed and fish oil groups when compared with the control diet. No significant change of total saturated fatty acids or ω-3 fatty acids was found in both rapeseed and beef tallow groups. Short-chain ω-3 α-linolenic acid (ALA) in flaxseed oil-fed group was efficiently converted to long-chain ω-3 docosahexaenoic acid (DHA) in the duck liver. This study showed the fatty acid profiling in the duck liver after various dietary fat consumption, provided insight into a dose response change of ω-3 fatty acids, indicated an efficient conversion of short- to long-chain ω-3 fatty acid, and suggested alternative long-chain ω-3 fatty acid-enriched duck products for human health benefits. In conclusion, the two studies in this dissertation provided a fundamental understanding of anti-cancer activity by sorghum phenolic extracts and the conversion of short- to long-chain ω-3 PUFAs in duck liver, contribute to a long term goal of promoting sorghum and duck as sustainable phenolic and ω-3 PUFAs sources as well as healthy food products for human beings

Assessment of the APCC Coupled MME Suite in Predicting the Distinctive Climate Impacts of Two Flavors of ENSO during Boreal Winter

Forecast skill of the APEC Climate Center (APCC) Multi-Model Ensemble (MME) seasonal forecast system in predicting two main types of El Nino-Southern Oscillation (ENSO), namely canonical (or cold tongue) and Modoki ENSO, and their regional climate impacts is assessed for boreal winter. The APCC MME is constructed by simple composite of ensemble forecasts from five independent coupled ocean-atmosphere climate models. Based on a hindcast set targeting boreal winter prediction for the period 19822004, we show that the MME can predict and discern the important differences in the patterns of tropical Pacific sea surface temperature anomaly between the canonical and Modoki ENSO one and four month ahead. Importantly, the four month lead MME beats the persistent forecast. The MME reasonably predicts the distinct impacts of the canonical ENSO, including the strong winter monsoon rainfall over East Asia, the below normal rainfall and above normal temperature over Australia, the anomalously wet conditions across the south and cold conditions over the whole area of USA, and the anomalously dry conditions over South America. However, there are some limitations in capturing its regional impacts, especially, over Australasia and tropical South America at a lead time of one and four months. Nonetheless, forecast skills for rainfall and temperature over East Asia and North America during ENSO Modoki are comparable to or slightly higher than those during canonical ENSO events

ENSO Atmospheric Teleconnections and Their Response to Greenhouse Gas Forcing

This is the final version of the article. Available from AGU via the DOI in this record.El Niño and Southern Oscillation (ENSO) is the most prominent year-to-year climate fluctuation on Earth, alternating between anomalously warm (El Niño) and cold (La Niña) sea surface temperature (SST) conditions in the tropical Pacific. ENSO exerts its impacts on remote regions of the globe through atmospheric teleconnections, affecting extreme weather events worldwide. However, these teleconnections are inherently nonlinear and sensitive to ENSO SST anomaly patterns and amplitudes. In addition, teleconnections are modulated by variability in the oceanic and atmopsheric mean state outside the tropics and by land and sea ice extent. The character of ENSO as well as the ocean mean state have changed since the 1990s, which might be due to either natural variability or anthropogenic forcing, or their combined influences. This has resulted in changes in ENSO atmospheric teleconnections in terms of precipitation and temperature in various parts of the globe. In addition, changes in ENSO teleconnection patterns have affected their predictability and the statistics of extreme events. However, the short observational record does not allow us to clearly distinguish which changes are robust and which are not. Climate models suggest that ENSO teleconnections will change because the mean atmospheric circulation will change due to anthropogenic forcing in the 21st century, which is independent of whether ENSO properties change or not. However, future ENSO teleconnection changes do not currently show strong intermodel agreement from region to region, highlighting the importance of identifying factors that affect uncertainty in future model projections.S. W. Y. is supported by the KoreaMeteorological Administration Researchand Development Program under grant KMIPA2015-2112. Wenju Cai is supported by Earth System and Climate Change Hub of the Australia National Environmental Science Programme, and Centre for Southern Hemisphere Oceans Research, an international collaboration between CSIRO and Qingdao National Laboratory for Marine Sciences and Technology. B. Dewitte acknowledges supports from FONDECYT(1151185) and from LEFE-GMMC. Dietmar Dommenget is supported by ARC Centre of Excellence for Climate System Science (CE110001028)

Towards an end-to-end analysis and prediction system for weather, climate, and marine applications in the Red Sea

Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 102(1), (2021): E99-E122, https://doi.org/10.1175/BAMS-D-19-0005.1.The Red Sea, home to the second-longest coral reef system in the world, is a vital resource for the Kingdom of Saudi Arabia. The Red Sea provides 90% of the Kingdom’s potable water by desalinization, supporting tourism, shipping, aquaculture, and fishing industries, which together contribute about 10%–20% of the country’s GDP. All these activities, and those elsewhere in the Red Sea region, critically depend on oceanic and atmospheric conditions. At a time of mega-development projects along the Red Sea coast, and global warming, authorities are working on optimizing the harnessing of environmental resources, including renewable energy and rainwater harvesting. All these require high-resolution weather and climate information. Toward this end, we have undertaken a multipronged research and development activity in which we are developing an integrated data-driven regional coupled modeling system. The telescopically nested components include 5-km- to 600-m-resolution atmospheric models to address weather and climate challenges, 4-km- to 50-m-resolution ocean models with regional and coastal configurations to simulate and predict the general and mesoscale circulation, 4-km- to 100-m-resolution ecosystem models to simulate the biogeochemistry, and 1-km- to 50-m-resolution wave models. In addition, a complementary probabilistic transport modeling system predicts dispersion of contaminant plumes, oil spill, and marine ecosystem connectivity. Advanced ensemble data assimilation capabilities have also been implemented for accurate forecasting. Resulting achievements include significant advancement in our understanding of the regional circulation and its connection to the global climate, development, and validation of long-term Red Sea regional atmospheric–oceanic–wave reanalyses and forecasting capacities. These products are being extensively used by academia, government, and industry in various weather and marine studies and operations, environmental policies, renewable energy applications, impact assessment, flood forecasting, and more.The development of the Red Sea modeling system is being supported by the Virtual Red Sea Initiative and the Competitive Research Grants (CRG) program from the Office of Sponsored Research at KAUST, Saudi Aramco Company through the Saudi ARAMCO Marine Environmental Center at KAUST, and by funds from KAEC, NEOM, and RSP through Beacon Development Company at KAUST