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Michael Notaro and Zhengyu Liu

1. Introduction Numerous modeling studies have indicated that vegetation can substantially impact the atmosphere, both locally and remotely. Fully coupled climate models have shown that vegetation’s influence on the atmosphere is established through biophysical feedbacks involving surface albedo (energy), evapotranspiration (moisture), and surface roughness (momentum). Within the boreal forests, the vegetation albedo feedback appears to be critical, particularly when the forest canopy masks the

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A. E. Viau and K. Gajewski

vegetation responds slowly to climate change, a conclusion that has, however, been questioned for many years ( Gajewski 1988 ; Viau et al. 2002 ; Williams et al. 2002 ; Gajewski et al. 2007 ). By computing regional averages ( Viau et al. 2006 ), we can attempt a continental-scale synthesis of the boreal zone of Canada and mitigate against some of these problems. Here we explore the use of regional paleoclimatic averages to study Holocene changes within the modern boreal zone of Canada. Although this

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Stefan Hastenrath, Dierk Polzin, and Charles Mutai

1. Introduction An earlier report in this journal ( Hastenrath et al. 2007 ) diagnosed the circulation mechanisms leading to the 2005 drought in equatorial East Africa, the failure of the boreal autumn “short rains.” During January 2009 repeated media reports were again received of severe drought conditions in many parts of Kenya. The failure of the boreal autumn short rains of 2008 and associated impacts on food, water, and other resources has been declared a national disaster in Kenya. This

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Y. Ming, V. Ramaswamy, and Gang Chen

1. Introduction The Earth’s climate system comprises distinct regimes, depending mainly on latitude and season. When one moves from the tropics into the wintertime extratropics, stationary Rossby waves and baroclinic eddies overtake the time-mean flow as the main mechanism of poleward energy and moisture transport. In light of the fundamental differences between the two climate regimes, we use this paper to examine specifically the impacts of aerosols on the boreal winter extratropical

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Hua Song and Minghua Zhang

the same as that of the total meridional wind. Because the trends are only statistically significant in the boreal winter season in both reanalyses, we restrict our study to the December–February (DJF) season. In addition to the winds, cloud fields and their radiative impacts in the reanalyses are also used. They are compared with the ship-based cloud observations from the Extended Edited Cloud Report Archive (EECRA; courtesy of J. Norris). Detailed information of the EECRA cloud data can be found

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Wanqiu Wang, Mingyue Chen, and Arun Kumar

1. Introduction The northward-propagating boreal summer intraseasonal oscillation (NPBSISO) over the Asian monsoon region was discovered by Yasunari (1979 , 1980) based on satellite-derived cloudiness data and confirmed by Yasunari (1981) and Krishnamurti and Subrahmanyam (1982) using wind observations. The NPBSISO is an essential part of the leading mode of intraseasonal variability during boreal summer, which consists of eastward propagation near the equator from the Indian Ocean to

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Judah Cohen, Mathew Barlow, and Kazuyuki Saito

anomalies observed over the high-latitude Northern Hemisphere (NH) during the boreal cold season. The skewed warming preferably toward the NH high latitudes during winter—polar and winter amplification—has been attributed to decreasing snow and ice cover ( Graversen et al. 2008 ; Stine et al. 2009 ). Observed changes to the climate system have spanned the seasons, including increased snowmelt and early peak river discharge in the spring ( Groisman et al. 1994 ; Rosenzweig et al. 2008 ), more intense

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Pierre-Erik Isabelle, Daniel F. Nadeau, Alain N. Rousseau, Carole Coursolle, and Hank A. Margolis

1. Introduction Peatlands account for 3.08 million km 2 or 10%–20% of the circumpolar boreal biome ( Aselmann and Crutzen 1989 ; Paavilainen and Päivänen 1995 ). Despite their widespread occurrence, they are typically found in remote areas, making their study difficult and costly. The water budgets of boreal peatlands are of great importance to accurately model regional hydrological processes in northern countries such as Canada, Finland, and Russia. To model water budgets, a precise estimate

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M. Alves, D. F. Nadeau, B. Music, F. Anctil, and A. Parajuli

1. Introduction Given their importance in climate regulation, much effort has been devoted to study boreal forests through numerous field experiments and modeling over the last decades ( Whittaker and Likens 1973 ; Schlesinger 1991 ; Stocks et al. 1998 ; Bonan 2008 ). Despite their complexity, surface processes taking place in this ecosystem, such as soil moisture evolution, snow accumulation/melt, and canopy interception, require an accurate representation in climate and weather prediction

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Bore-ing into Nocturnal Convection

Kevin R. Haghi, Bart Geerts, Hristo G. Chipilski, Aaron Johnson, Samuel Degelia, David Imy, David B. Parsons, Rebecca D. Adams-Selin, David D. Turner, and Xuguang Wang

This article presents a survey of atmospheric bores, their role in the initiation and organization of deep convection, and a vision for improving the forecast of atmospheric bores and nocturnal convection through a multidisciplinary approach. On the afternoon of the 10 July 2015 in Hays, Kansas, during the Plains Elevated Convection at Night (PECAN) field campaign ( Geerts et al. 2017 ), the bore group was selected to lead the evening’s intensive observation period (IOP). The PECAN forecasters

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