Journal of Climate back issues from November 2008:
Influence of Indian Ocean Dipole on Poleward Propagation of Boreal Summer Intraseasonal Oscillations
Nov 01, 2008; ... ABSTRACT The influence of the Indian Ocean dipole (IOD) on the poleward propagation of boreal summer intraseasonal oscillations (BSISOs) is examined using observed datasets. This study finds that coherent (incoherent) poleward propagation of precipitation anomalies from 5°S to 25°N are ...
Observed Changes in Return Values of Annual Temperature Extremes over Argentina
Nov 01, 2008; ... ABSTRACT Extreme temperature events are one of the most studied extreme events since their occurrence has a huge impact on society. In this study, the frequency of occurrence of absolute extreme temperature events in Argentina is analyzed. Four annual extremes are defined based on ...
Evaluating the Performance of Land Surface Models
Nov 01, 2008; ... ABSTRACT This paper presents a set of analytical tools to evaluate the performance of three land surface models (LSMs) that are used in global climate models (GCMs). Predictions of the fluxes of sensible heat, latent heat, and net CO2 exchange obtained using process-based LSMs are ...
Decadal Modulation of ENSO in a Hybrid Coupled Model
Nov 01, 2008; ... ABSTRACT Decadal variations in the amplitude of El Niño and the Southern Oscillation have been the subject of great interest in the literature for the past decade. One theory suggests that ENSO is best described as a stable system driven by linear dynamics and that stochastic atmospheric ...
Coupled Ocean-Atmosphere Interaction and Variability in the Tropical Atlantic Ocean with and without an Annual Cycle
Nov 01, 2008; ... ABSTRACT Many previous studies point to a connection between the annual cycle and interannual variability in the tropical Atlantic Ocean. To investigate the importance of the annual cycle in the generation of tropical Atlantic variability (TAV) as well as its associated coupled feedback ...
On Multidecadal Variability of the Atlantic Meridional Overturning Circulation in the Community Climate System Model Version 3
Nov 01, 2008; ... ABSTRACT Multidecadal variability of the Atlantic meridional overturning circulation (MOC) is investigated diagnostically in the NCAR Community Climate System Model version 3 (CCSM3) present-day simulations, using the highest (T85 × 1) resolution version. This variability has a 21-yr ...
Decadal Variability of the Indo-Pacific Warm Pool and Its Association with Atmospheric and Oceanic Variability in the NCEP-NCAR and SODA Reanalyses
Nov 01, 2008; ... ABSTRACT Decadal variability of the Indo-Pacific warm pool (IPWP) sea surface temperature (SST) and its association with atmospheric and oceanic circulations are investigated with observed 50-yr (1952-2001) SST, and the NCEP-NCAR atmospheric and Simple Ocean Data Assimilation (SODA) ...
Southern Hemisphere Synoptic Behavior in Extreme Phases of SAM, ENSO, Sea Ice Extent, and Southern Australia Rainfall
Nov 01, 2008; ... ABSTRACT The association between Southern Hemisphere cyclones and anticyclones and the El Niño-Southern Oscillation (ENSO), southern annular mode (SAM), Antarctic sea ice extent (SIE), and rainfall in Perth and Melbourne is explored. Those cities are, respectively, located in the ...
Mechanisms of Global Warming Impacts on Robustness of Tropical Precipitation Asymmetry
Nov 01, 2008; ... ABSTRACT Hemispherically and temporally asymmetric tropical precipitation responses to global warming are evaluated in 13 different coupled atmosphere-ocean climate model simulations. In the late boreal summer, hemispherical averages of the tropical precipitation anomalies from the ...
Potential Biases in Feedback Diagnosis from Observational Data: A Simple Model Demonstration
Nov 01, 2008; ... ABSTRACT Feedbacks are widely considered to be the largest source of uncertainty in determining the sensitivity of the climate system to increasing anthropogenic greenhouse gas concentrations, yet the ability to diagnose them from observations has remained controversial. Here a simple ...
The Role of the Western Arabian Sea Upwelling in Indian Monsoon Rainfall Variability
Nov 01, 2008; ... ABSTRACT The Indian summer monsoon rainfall has complex, regionally heterogeneous, interannual variations with huge socioeconomic impacts, but the underlying mechanisms remain uncertain. The upwelling along the Somalia and Oman coasts starts in late spring, peaks during the summer ...
Estimating Annual Global Upper-Ocean Heat Content Anomalies despite Irregular In Situ Ocean Sampling*
Nov 01, 2008; ... ABSTRACT The effects of irregular in situ ocean sampling on estimates of annual globally integrated upper ocean heat content anomalies (OHCA) are investigated for sampling patterns from 1955 to 2006. An analytical method is presented for computing the effective area covered by an ...
On the Strong Seasonal Currents in the Deep Ocean
Nov 01, 2008; ... ABSTRACT Using a set of models, including one with a resolution of ¼°, several aspects of the simulated seasonal currents in the deep ocean are considered. It is shown that over vast areas of the deep interior, particularly in the Indian Ocean, annual-mean circulation represents a small ...
Changing Expendable Bathythermograph Fall Rates and Their Impact on Estimates of Thermosteric Sea Level Rise
Nov 01, 2008; ... ABSTRACT A time-varying warm bias in the global XBT data archive is demonstrated to be largely due to changes in the fall rate of XBT probes likely associated with small manufacturing changes at the factory. Deep-reaching XBTs have a different fall rate history than shallow XBTs. Fall ...
An Improved Parameterization for Simulating Arctic Cloud Amount in the CCSM3 Climate Model
Nov 01, 2008; ... ABSTRACT A simple alternative parameterization for predicting cloud fraction in the Community Climate System Model, version 3 (CCSM3) global climate model is presented. This formula, dubbed "freeezedry," is designed to alleviate the bias of excessive low clouds during polar winter by ...
The Role of Ekman Ocean Heat Transport in the Northern Hemisphere Response to ENSO
Nov 01, 2008; ... ABSTRACT The influence of oceanic Ekman heat transport (Q^sub ek^) on air-sea variability associated with ENSO teleconnections is examined via a pair of atmospheric general circulation model (AGCM) experiments. In the mixed layer model (MLM) experiment, observed sea surface temperatures ...
A High-Resolution Climate Model for the U.S. Pacific Northwest: Mesoscale Feedbacks and Local Responses to Climate Change*
Nov 01, 2008; ... ABSTRACT Simulations of future climate scenarios produced with a high-resolution climate model show markedly different trends in temperature and precipitation over the Pacific Northwest than in the global model in which it is nested, apparently because of mesoscale processes not being ...
Possible Role of the Indian Ocean in the In-Phase Transition of the Indian-to-Australian Summer Monsoon
Nov 01, 2008; ... ABSTRACT Analysis of observations shows that in-phase transitions from the Indian summer monsoon (ISM) to the Australian summer monsoon (ASM) have occurred both in El Niño-Southern Oscillation (ENSO) and non-ENSO years. The present study investigates possible roles of the Indian Ocean in ...
Midlatitude Cyclone Compositing to Constrain Climate Model Behavior Using Satellite Observations
Nov 15, 2008; ... ABSTRACT Identical composite analysis of midlatitude cyclones over oceanic regions has been carried out on both output from the NCAR Community Atmosphere Model, version 3 (CAM3) and multisensor satellite data. By focusing on mean fields associated with a single phenomenon, the ability of ...
Recent Changes in Downward Longwave Radiation at King Sejong Station, Antarctica
Nov 15, 2008; ... ABSTRACT Effects of cloud, air temperature, and specific humidity on downward longwave irradiance and their long-term variabilities are examined by analyzing the measurements made at the King Sejong Station in the Antarctic Peninsula during the period of 1996-2006. It has been ...
Energy of Midlatitude Transient Eddies in Idealized Simulations of Changed Climates
Nov 15, 2008; ... ABSTRACT As the climate changes, changes in static stability, meridional temperature gradients, and availability of moisture for latent heat release may exert competing effects on the energy of midlatitude transient eddies. This paper examines how the eddy kinetic energy in midlatitude ...
Influence of a New Turbulence Regime on the Global Air-Sea Heat Fluxes
Nov 15, 2008; ... ABSTRACT Recent research has found that boundary layer turbulence changes its organization as the stratification approaches neutral from the unstable side. When the thermal forcing weakens in combination with wind speed above approximately 10 m s^sup -1^, detached eddies are formed in ...
The Impact of Air-Sea Interactions on the Predictability of the Tropical Intraseasonal Oscillation
Nov 15, 2008; ... ABSTRACT This study investigates whether air-sea interactions contribute to differences in the predictability of the boreal winter tropical intraseasonal oscillation (TISO) using the NCEP operational climate model. A series of coupled and uncoupled, "perfect" model predictability ...
The Equatorial Pacific Cold Tongue Bias in a Coupled Climate Model
Nov 15, 2008; ... ABSTRACT A set of multidecadal coupled ocean-atmosphere model integrations are conducted with different time steps for coupling between the atmosphere and the ocean. It is shown that the mean state of the equatorial Pacific does not change in a statistically significant manner when the ...
Changes in Frequency of Precipitation Types Associated with Surface Air Temperature over Northern Eurasia during 1936-90
Nov 15, 2008; ... ABSTRACT Potential benefits or disadvantages of increasing precipitation in high-latitude regions under a warming climate are dependent on how and in what form the precipitation occurs. Precipitation frequency and type are equally as important as quantity and intensity to understanding ...
Impact of Historical Climate Change on the Southern Ocean Carbon Cycle
Nov 15, 2008; ... ABSTRACT Climate change over the last several decades is suggested to cause a decrease in the magnitude of the uptake of CO2 by the Southern Ocean (Le Quere et al.). In this study, the atmospheric fields from NCEP R1 for the years 1948-2003 are used to drive an ocean biogeochemical model ...
Interannual Atmospheric Variability Affects Continental Ice Sheet Simulations on Millennial Time Scales
Nov 15, 2008; ... ABSTRACT To inform the ongoing development of earth system models that aim to incorporate interactive ice, the potential impact of interannual variability associated with synoptic variability and El Niño-Southern Oscillation (ENSO) at the Last Glacial Maximum (LGM) on the evolution of a ...
Phase Speed Spectra and the Latitude of Surface Westerlies: Interannual Variability and Global Warming Trend
Nov 15, 2008; ... ABSTRACT The extratropical annular-mode-like atmospheric responses to ENSO and global warming and the internal variability of annular modes are associated with similar, yet distinct, dynamical characteristics. In particular, La Niña, global warming, and the positive phase of annular ...
Seasonal Variation of the Diurnal Cycle of Rainfall in Southern Contiguous China
Nov 15, 2008; ... ABSTRACT Hourly station rain gauge data are employed to study the seasonal variation of the diurnal cycle of rainfall in southern contiguous China. The results show a robust seasonal variation of the rainfall diurnal cycle, which is dependent both on region and duration. Difference in ...
Deep Atmospheric Response to the North Pacific Oceanic Subtropical Front in Spring
Nov 15, 2008; ... ABSTRACT The North Pacific subtropical front (STF) is a zone of high sea surface temperature (SST) gradients located around 25°N in the western basin and is most pronounced in spring. The STF's atmospheric effects are investigated using satellite observations and an atmospheric ...
Response of the Zonal Mean Atmospheric Circulation to El Niño versus Global Warming
Nov 15, 2008; ... ABSTRACT The change in the zonal mean atmospheric circulation under global wanning is studied in comparison with the response to El Niño forcing, by examining the model simulations conducted for the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. In contrast to ...
Arctic Climate Change as Manifest in Cyclone Behavior
Nov 15, 2008; ... ABSTRACT The Arctic region has exhibited dramatic changes in recent times. Many of these are intimately tied up with synoptic activity, but little research has been undertaken on how the characteristics of Arctic cyclones have changed. This paper presents a comprehensive analysis of ...
The Impact of Convection on ENSO: From a Delayed Oscillator to a Series of Events
Nov 15, 2008; ... ABSTRACT The NCAR Community Climate System Model, version 3 (CCSM3) exhibits persistent errors in its simulation of the El Niño-Southern Oscillation (ENSO) mode of coupled variability. The amplitude of the oscillation is too strong, the dominant 2-yr period too regular, and the width of ...
Comparison of Daily Precipitation Statistics for the United States in Observations and in the NCEP Climate Forecast System
Nov 15, 2008; ... ABSTRACT An intercomparison of the statistics of daily precipitation within seasonal climate over the conterminous United States is carried out using gridded station data and output from the NCEP Climate Forecast System (CFS). Differences in the occurrence of daily precipitation between ...
Evaluating the Consistency between Statistically Downscaled and Global Dynamical Model Climate Change Projections
Nov 15, 2008; ... ABSTRACT The consistency between rainfall projections obtained from direct climate model output and statistical downscaling is evaluated. Results are averaged across an area large enough to overcome the difference in spatial scale between these two types of projections and thus make the ...
Changes in ENSO and Associated Overturning Circulations from Enhanced Greenhouse Gases by the End of the Twentieth Century
Nov 15, 2008; ... ABSTRACT With data from 12 coupled models in the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC), climate under year 2000 greenhouse gas (GHG) + aerosol forcing was compared with climate under preindustrial conditions. In the tropical Pacific, the ...
Eastern Equatorial Pacific Forcing of ENSO Sea Surface Temperature Anomalies*
Nov 15, 2008; ... ABSTRACT Previous studies have described the impacts of wind stress variations in the eastern Pacific on sea surface temperature (SST) anomalies associated with the El Niño-Southern Oscillation (ENSO) phenomenon. However, these studies have usually focused on individual El Niño events ...
A Joint Statistical and Dynamical Assessment of Atmospheric Response to North Pacific Oceanic Variability in CCSM3
Nov 15, 2008; ... ABSTRACT Atmospheric response to North Pacific oceanic variability is assessed in Community Climate System Model, version 3 (CCSM3) using two statistical methods and one dynamical method. All methods identify an equivalent barotropic low response to a wanner sea surface temperature (SST) ...
Low-Frequency Modulation of Intraseasonal Equatorial Kelvin Wave Activity in the Pacific from SODA: 1958-2001
Nov 15, 2008; ... ABSTRACT Intraseasonal equatorial Kelvin wave activity (IEKW) at a low frequency in the Pacific is investigated using the Simple Ocean Data Assimilation (SODA) oceanic reanalyses. A vertical and horizontal mode decomposition of SODA variability allows estimation of the Kelvin wave ...
Global Decadal Upper-Ocean Heat Content as Viewed in Nine Analyses
Nov 15, 2008; ... ABSTRACT This paper examines nine analyses of global ocean 0-/700-m temperature and heat content during the 43-yr period of warming, 1960-2002. Among the analyses are two that are independent of any numerical model, six that rely on sequential data assimilation, including an ocean ...
Tropical Indian Ocean Basin Warming and East Asian Summer Monsoon: A Multiple AGCM Study
Nov 15, 2008; ... ABSTRACT A basin-scale warming is the leading mode of tropical Indian Ocean sea surface temperature (SST) variability on interannual time scales, and it is also the prominent feature of the interdecadal SST trend in recent decades. The influence of the warming on the East Asian summer ...
Spatial and Temporal Trends in Sunshine Duration over Western Europe (1938-2004)
Nov 15, 2008; ... ABSTRACT This work analyzes sunshine duration variability in the western part of Europe (WEU) over the 1938-2004 period. A principal component analysis is applied to cluster the original series from 79 sites into 6 regions, and then annual and seasonal mean series are constructed on ...