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Jennifer L. Adams and David J. Stensrud

1. Introduction During the warm season, there is a distinct maximum in rainfall over the southwestern United States and northwestern Mexico due to the North American monsoon (NAM). The NAM accounts for 60%–80% of the annual rainfall in northwestern Mexico and nearly 40% of the annual rainfall in Arizona ( Douglas et al. 1993 ). Several areas in Mexico receive greater than 900 mm of rain during the NAM, and along the slopes of the Sierra Madre Occidental (SMO) the ground cover drastically

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Mathieu Joly and Aurore Voldoire

1. Introduction Over the Sahelian region, the livelihoods and even the lives of most people are directly tied to the amount of monsoon rainfall in the boreal summer. Any progress in the understanding and forecasting of the African climate is therefore of great importance. The causes of the interdecadal variability of Sahelian rainfall and the possible impacts of global warming are still open questions. In addition to the interdecadal variability, Sahelian rainfall also presents a strong

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Dabang Jiang and Xianmei Lang

1. Introduction A variety of climate states and events have been recorded in the earth’s history. Insights into the facts and mechanisms of past climate and environmental change are essential for understanding present and future climate change. In the geosciences, a central issue in the field of paleoclimatology is the accurate reconstruction of changes in the East Asian monsoon at a range of time scales and seeking reasons for these changes through the use of proxy data and physically based

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Renguang Wu and Ben P. Kirtman

1. Introduction The region encompassing Indonesia, northern Australia, and nearby waters displays strong monsoon characteristics ( Ramage 1971 ; Murakami and Matsumoto 1994 ), with prevailing easterly winds and dry conditions during boreal summer and prevailing westerly winds and wet conditions during boreal winter ( Hendon 2003 ; Hung et al. 2004 ; Chang et al. 2005 ). This region, for simplicity, is termed the Australian monsoon region hereafter. In boreal winter (austral summer), active

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Philippe Lucas-Picher, Jens H. Christensen, Fahad Saeed, Pankaj Kumar, Shakeel Asharaf, Bodo Ahrens, Andrew J. Wiltshire, Daniela Jacob, and Stefan Hagemann

1. Introduction South Asian summer is dominated by the Indian monsoon, which spans four months from June to September and provides the major input of water for a large fraction of the world total population living in India, Bangladesh, Myanmar, and Nepal ( Goswami 2005 ). Most global climate models (GCMs) simulate the general migration of the seasonal tropical rain (e.g., Christensen et al. 2007 ). However, the observed maximum rainfalls during the monsoon season along the west coast of India

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David K. Adams and Enio P. Souza

and convection during the Australian monsoon, McBride and Frank (1999) found negative relationships between CAPE and areal measures of precipitation with large sensitivity to parcel level of origin. Near-surface parcels were shown to correlate negatively with convective activity, while parcels only 100 hPa above surface level were uncorrelated with convection. Over the tropical oceans, Sobel et al. (2004) and Yano et al. (2005) found a weak negative correlation between convection and

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V. Krishnamurthy and J. Shukla

1. Introduction The intraseasonal variation of the Indian monsoon consists of “active” periods of high rainfall and “break” periods of deficient or no rainfall during the summer season [June–September (JJAS)]. The JJAS seasonal mean rainfall varies from year to year and is known to have strong associations with other global phenomena through the influence of sea surface temperature (SST), snow, and soil moisture (see, e.g., Krishnamurthy and Kinter 2003 ). Based on model experiments, Charney

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Yueqing Li and Song Yang

1. Introduction The East Asian winter monsoon (EAWM) not only produces large-scale northerly surges and temperature drops across East Asia but also exerts a strong influence on the climate over remote regions ( Chang and Lau 1982 ; Ding and Krishnamurti 1987 ; Chan and Li 2004 ; Wang 2006 ). Accumulated evidence has indicated that the variability of EAWM can cause substantial social and economic losses, and it is still a challenge to predict the EAWM accurately ( Webster et al. 1998 ; Huang

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C. Shaji and A. Gangopadhyay

technique for the upwelling region associated with the West India Coastal Current (WICC) in the eastern Arabian Sea during the southwest monsoon in the boreal summer season. We use the Levitus (0.25° × 0.25°) climatology as the background field. At this time, we have mainly focused on the eastern Arabian Sea because we were able to get some observational data from this region. Later on, this technique can be applied in other upwelling regions in the Arabian Sea and also different formulations can be

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Liguang Wu, Jia Liang, and Chun-Chieh Wu

; Lee et al. 2008 ; Jian and Wu 2008 ; Yang et al. 2008 ; Wu et al. 2009 ). These numerical studies support that the topographic effect of the island can deflect TC tracks, modify the TC structure, and enhance TC rainfall. However, compared to the topographic effect, relatively few studies have been conducted on the interaction between Asian monsoon systems and TCs although the interaction can lead to torrential rainfall over Taiwan ( Chien et al. 2008 ; Wu et al. 2009 ). The monsoon activity in

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