South Asian summermonsoon breaks: Process-based diagnostics in HIRHAM5

This study assesses the ability of a high-resolution downscaling simulation with the regional climate model (RCM) HIRHAM5 in capturing the monsoon basic state and boreal summer intraseasonal variability (BSISV) over South Asia with focus on moist and radiative processes during 1979–2012. A process-based vertically integrated moist static energy (MSE) budget is performed to understand the model’s fidelity in representing leading processes that govern the monsoon breaks over continental India. In the climatology (June–September) HIRHAM5 simulates a dry bias over central India in association with descent throughout the free troposphere. Sources of dry bias are interpreted as (i) near-equatorial Rossby wave response forced by excess rainfall over the southern Bay of Bengal promotes anomalous descent to its northwest and (ii) excessive rainfall over near-equatorial Arabian Sea and Bay of Bengal anchor a “local Hadley-type” circulation with descent anomalies over continental India. Compared with observations HIRHAM5 captures the leading processes that account for breaks, although with generally reduced amplitudes over central India. In the model too, anomalous dry advection and net radiative cooling are responsible for the initiation and maintenance of breaks, respectively. However, weaker contributions of all adiabatic MSE budget terms, and an inconsistent relationship between negative rainfall anomalies and radiative cooling reveals shortcomings in HIRHAM5’s moisture-radiation interaction. Our study directly implies that process-based budget diagnostics are necessary, apart from just checking the northward propagation feature to examine RCM’s fidelity to simulate BSISV

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ENSO’s far reaching connection to Indian cold waves

During boreal winters, cold waves over India are primarily due to transport of cold air from higher latitudes. However, the processes associated with these cold waves are not yet clearly understood. Here by diagnosing a suite of datasets, we explore the mechanisms leading to the development and maintenance of these cold waves. Two types of cold waves are identified based on observed minimum surface temperature and statistical analysis. The first type (TYPE1), also the dominant one, depicts colder than normal temperatures covering most parts of the country while the second type (TYPE2) is more regional, with significant cold temperatures only noticeable over northwest India. Quite interestingly the first (second) type is associated with La Niña (El Niño) like conditions, suggesting that both phases of ENSO provide a favorable background for the occurrence of cold waves over India. During TYPE1 cold wave events, a low-level cyclonic anomaly generated over the Indian region as an atmospheric response to the equatorial convective anomalies is seen advecting cold temperatures into India and maintaining the cold waves. In TYPE2 cold waves, a cyclonic anomaly generated over west India anomalously brings cold winds to northwest India causing cold waves only in those parts

Origin of a trend in ECMWF wind analysis and its objective removal

The suitability of the European Centre for Medium Range Weather Forecasting (ECMWF) operational wind analysis for the period 1980-1991 for studying interannual variability is examined. The changes in the model and the analysis procedure are shown to give rise to a systematic and significant trend in the large scale circulation features. A new method of removing the systematic errors at all levels is presented using multivariate EOF analysis. Objectively detrended analysis of the three-dimensional wind field agrees well with independent Florida State University (FSU) wind analysis at the surface. It is shown that the interannual variations in the detrended surface analysis agree well in amplitude as well as spatial patterns with those of the FSU analysis. Therefore, the detrended analyses at other levels as well are expected to be useful for studies of variability and predictability at interannual time scales. It is demonstrated that this trend in the wind field is due to the shift in the climatologies from the period 1980-1985 to the period 1986-1991

Coupled Model Simulations of Boreal Summer Intraseasonal (30-50 day) Variability, Part 1: Systematic Errors and Caution on Use of Metrics

Boreal summer intraseasonal (30-50 day) variability (BSISV) over the Asian monsoon region is more complex than its boreal winter counterpart, the Madden-Julian oscillation (MJO), since it also exhibits northward and northwestward propagating convective components near India and over the west Pacific. Here we analyze the BSISV in the CMIP3 and two CMIP2+ coupled ocean-atmosphere models. Though most models exhibit eastward propagation of convective anomalies over the Indian Ocean, difficulty remains in simulating the life cycle of the BSISV, as few represent its eastward extension into the western/central Pacific. As such, few models produce statistically significant anomalies that comprise the northwest to southeast tilted convection which results from the forced Rossby waves that are excited by the near-equatorial convective anomalies. Our results indicate that it is a necessary, but not sufficient condition, that the locations the time-mean monsoon heat sources and the easterly wind shear be simulated correctly in order for the life cycle of the BSISV to be represented realistically. Extreme caution is needed when using metrics, such as the pattern correlation, for assessing the fidelity of model performance, as models with the most physically realistic BSISV do not necessarily exhibit the highest pattern correlations with observations. Furthermore, diagnostic latitude-time plots to evaluate the northward propagation of convection from the equator to India and the Bay of Bengal also need to be used with caution. Here, incorrectly representing extratropical-tropical interactions can give rise to 'apparent' northward propagation when none exists in association with the eastward propagating equatorial convection. It is necessary to use multiple cross-checking diagnostics to demonstrate the fidelity of the simulation of the BSISV

Exploring the Adoption of Multiple Intelligences in Micro Credentials by Educators in Malaysian Higher Education

This study explored the multiple intelligence representation in the micro-credentials designed by Malaysian educators and the reasons for integrating multiple intelligences in their course materials. The study was guided by the eight indicators of multiple intelligences suggested by Howard Gardner. We conducted in-depth qualitative interviews with 20 educators from a university in the northern region of Malaysia. The thematic analysis guided by Braun and Clarke shows a number of reasons why educators included the indicators in designing their content for micro-credential. Educators generally demonstrated that they used all the multiple intelligences indicators in designing the micro-credentials. The findings are encouraging and suggest that all eight intelligences can be included in designing micro–credentials to enhance students\u27 learning experiences with the help of technology. Finally, the authors suggest a pedagogical framework that can be considered by educators who intend to design the micro-credentials

High school teachers’ perception of AR and VR in English language teaching and learning activities : A developing country perspective

AR and VR are new introductions in many developing countries, including Malaysia. The present study conducted a qualitative case study with 23 high school teachers and investigated their perceptions of AR and VR in English language teaching and learning activities. A semi-structured interview was employed to collect the data. The data was analysed based on the thematic analysis suggested by Braun and Clarke (Qualitative Research in Psychology, 3(2), 77–101, 2006). The findings revealed positive and negative perceptions of integrating AR and VR in English language teaching and learning activities. The positive themes were related to effective English language learning, engaging students, bringing your own device (BYOD) and active learning. The negative perceptions were related to time-consuming and health-related matters. The study further suggested approaches that might be effective in adopting AR and VR in English language teaching and learning activities. It is hoped that the outcome of the present study can provide insights for teachers, curriculum planners, and policymakers to consider the strengths and limitations of AR and VR before it is integrated into English language teaching and learning activities

South Asian Summer Monsoon and Its Relationship with ENSO in the IPCC AR4 Simulations

In this paper we use the extensive integrations produced for the IPCC Fourth Assessment Report (AR4) to examine the relationship between ENSO and the monsoon at interannual and decadal timescales. We begin with an analysis of the monsoon simulation in the 20th century integrations. Six of the 18 models were found to have a reasonably realistic representation of monsoon precipitation climatology. For each of these six models SST and anomalous precipitation evolution along the equatorial Pacific during El Nino events display considerable differences when compared to observations. Out of these six models only four (GFDL{_}CM{_}2.0, GFDL{_}CM{_}2.1, MRI, and MPI{_}ECHAM5) exhibit a robust ENSO-monsoon contemporaneous teleconnection, including the known inverse relationship between ENSO and rainfall variations over India. Lagged correlations between the all-India rainfall (AIR) index and Nino3.4 SST reveal that three models represent the timing of the teleconnection, including the spring predictability barrier which is manifested as the transition from positive to negative correlations prior to the monsoon onset. Furthermore, only one of these three models (GFDL{_}CM{_}2.1) captures the observed phase lag with the strongest anticorrelation of SST peaking 2-3 months after the summer monsoon, which is partially attributable to the intensity of simulated El Nino itself. We find that the models that best capture the ENSO-monsoon teleconnection are those that correctly simulate the timing and location of SST and diabatic heating anomalies in the equatorial Pacific, and the associated changes to the equatorial Walker Circulation during El Nino events. The strength of the AIR-Nino3.4 SST correlation in the model runs waxes and wanes to some degree on decadal timescales. The overall magnitude and timescale for this decadal modulation in most of the models is similar to that seen in observations. However, there is little consistency in the phase among the realizations, suggesting a lack of predictability of the decadal modulation of the monsoon-ENSO relationship. The analysis was repeated for each of the four models using results from integrations in which the atmospheric CO{sub 2} concentration was raised to twice pre-industrial values. From these ''best'' models in the double CO{sub 2} simulations there are increases in both the mean monsoon rainfall over the Indian sub-continent (by 5-25%) and in its interannual variability (5-10%). We find for each model that the ENSO-monsoon correlation in the global warming runs is very similar to that in the 20th century runs, suggesting that the ENSO-monsoon connection will not weaken as global climate warms. This result, though plausible, needs to be taken with some caution because of the diversity in the simulation of ENSO variability in the coupled models we have analyzed. The implication of the present results for monsoon prediction are discussed

Nonlinear Modes of Liquid Drops as Solitary Waves

The nolinear hydrodynamic equations of the surface of a liquid drop are shown to be directly connected to Korteweg de Vries (KdV, MKdV) systems, giving traveling solutions that are cnoidal waves. They generate multiscale patterns ranging from small harmonic oscillations (linearized model), to nonlinear oscillations, up through solitary waves. These non-axis-symmetric localized shapes are also described by a KdV Hamiltonian system. Recently such ``rotons'' were observed experimentally when the shape oscillations of a droplet became nonlinear. The results apply to drop-like systems from cluster formation to stellar models, including hyperdeformed nuclei and fission.Comment: 11 pages RevTex, 1 figure p