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Kevin E. Trenberth, Lesley Smith, Taotao Qian, Aiguo Dai, and John Fasullo

. 2005 ). The strong relationships with sea surface temperatures (SSTs) allow estimates of column water vapor amounts since 1970 to be made and results indicate increases of about 4% over the global oceans, suggesting that water vapor feedback has led to a radiative effect of about 1.5 W m −2 ( Fasullo and Sun 2001 ), comparable to the radiative forcing of carbon dioxide increases ( Houghton et al. 2001 ). This provides direct evidence for strong water vapor feedback in climate change. The observed

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Xubin Zeng and Aihui Wang

temperature over semiarid regions in the earlier version of CLM, and has been implemented into the CLM3. As a continuity of our efforts in the consistent treatment of atmospheric turbulence under and within canopy ( Zeng et al. 2005 ), over bare soil ( Zeng and Dickinson 1998 ), ocean (e.g., Zeng et al. 1998 ), and sea ice ( Brunke et al. 2006 ), here we address another deficiency of many land models (e.g., CLM3); that is, the failure to consider the convergence of canopy roughness length ( z oc ) and

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Guoxiong Wu, Yimin Liu, Qiong Zhang, Anmin Duan, Tongmei Wang, Rijin Wan, Xin Liu, Weiping Li, Zaizhi Wang, and Xiaoyun Liang

circulation as first reported by Yeh et al. (1959) . To demonstrate this, the low-resolution version R15L9 of the GOALS-SAMIL model is employed to initiate a set of sensitivity experiments. In the first experiment, for the calculation of radiation the cloud distributions are prescribed by using satellite remote sensing data. The observed distributions of sea surface temperature and sea ice from 1979 to 1988, which were set for the AMIP experiments, are introduced as the prescribed lower

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Richard G. Lawford, John Roads, Dennis P. Lettenmaier, and Phillip Arkin

small ice particles. b. Precipitation extremes GEWEX precipitation products provide a broad view of the water cycle that includes oceans as well as land areas including the effects of El Niño events on precipitation. Gu et al. (2007) have shown that in the Tropics over 37% of the spatial extent of rainfall extremes over the oceans are explained by sea surface temperature variations associated with ENSO events. In particular, El Niño events are associated with rainfall deficiencies over the oceans

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Song Yang, S-H. Yoo, R. Yang, K. E. Mitchell, H. van den Dool, and R. W. Higgins

Regional Reanalysis (NARR; Mesinger et al. 2006 ). Specifically, it is the RCM-configured version of the Eta Model executing operationally at NCEP in November 2001. With respect to the latter numerical weather prediction version, we made traditional changes to achieve the RCM configuration, namely, to enable longer-period model integrations and to invoke daily updates of (i) SST and sea ice from external analyses and (ii) fraction of green vegetation cover and albedo from temporal interpolation of

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Yefim L. Kogan, Zena N. Kogan, and David B. Mechem

1. Introduction Marine stratus and stratocumulus clouds play an important role in global water and energy budget by increasing the local planetary albedo by 30%–50% while having relatively little impact on outgoing longwave radiation. These clouds are widespread and at any given time may cover much of the eastern subtropical Pacific and Atlantic, most of the Arctic Sea in summer, and large regions of the middle latitudes. Charlson et al. (1987) estimate that stratus and stratocumulus clouds

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J. Li, X. Gao, and S. Sorooshian

( Chen and Dudhia 2001 ). National Centers for Environmental Prediction (NCEP) reanalysis data (at a 2.5° resolution) were used as the initial and boundary forcing data. Reynolds 1° × 1° sea surface temperature (SST) data were used as the oceanic surface boundary forcing. The Reynolds SST is the only dataset archived in the study’s time periods, although a preliminary study by our group showed that rainfall distribution and amount may be influenced by using different types of SST datasets in MM5 ( Li

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Jinwon Kim and Hyun-Suk Kang

. 2006 ). b. Simulation and case selection A winter season simulation has been performed over the 4-month period December 1997–March 1998 using large-scale atmospheric and sea surface temperature (SST) forcing data from National Centers for Environmental Prediction–Department of Energy (NCEP–DOE) reanalysis version 2 ( Kanamitsu et al. 2002 ). To investigate orographic blocking by the Sierra Nevada and its impact on low-level winds, moisture transport, and precipitation over the mountain range, we

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