The study of climate and change is hindered by a lack information on the effect clouds radiation balance earth, referred to as cloud-radiative forcing. Quantitative estimates global distributions forcing have been obtained from spaceborne Earth Radiation Budget Experiment (ERBE) launched in 1984. For April 1985 period, shortwave cloud [-44.5 watts per square meter (W/m 2 )] due enhancement planetary albedo, exceeded magnitude longwave (31.3 W/m ) resulting greenhouse clouds. Thus, had net...

The seasonal cycle of low stratiform clouds is studied using data from surface-based cloud climatologies. impact on the radiation budget illustrated by comparison Earth Radiation Budget Experiment with Ten regions active stratocumulus convection are identified. These fall into four categories: subtropical marine, midlatitude Arctic stratus, and Chinese stratus. With exception region, all high amounts stratus over oceans. In except Arctic, season maximum corresponds to greatest...

The role of fractional area coverage by cloud types in the energy balance earth is investigated through joint use International Satellite Cloud Climatology Project (ISCCP) C1 data and Earth Radiation Budget Experiment (ERBE) broadband flux for one-year period March 1985 February 1986. Multiple linear regression used to relate radiation budget data. Comparing forcing estimates obtained from ISCCP-ERBE with those derived ERBE scene identification shows generally good agreement except over...

Motivated by recent evidence of strong stratospheric–tropospheric coupling during the Northern Hemisphere winter, this study examines evolution atmospheric flow and wave fluxes at levels throughout stratosphere troposphere composite life cycle a sudden stratospheric warming. The comprises 39 major minor warming events using 44 years NCEP–NCAR reanalysis data. incipient stage is characterized preconditioning zonal anomalous, quasi-stationary wavenumber-1 forcing in both troposphere. As...

Hurricane and tropical storm statistics verify the modulation of eastern Pacific systems by Madden–Julian oscillation (MJO) as hypothesized Maloney Hartmann. Over twice many named (hurricanes storms) accompany equatorial 850-mb westerly anomalies than easterly anomalies, that do exist are stronger. Hurricanes over four times more numerous during phases MJO phases. The current study constructs a composite life cycle May–November 1979–95 using an index based on zonal wind. Equatorial Kelvin...

Tropical convective anvil clouds detrain preferentially near 200 hPa. It is argued here that this occurs because clear‐sky radiative cooling decreases rapidly This rapid decline of longwave emission from water vapor becomes inefficient above The less important than the CO 2 saturation pressure so very low at temperatures suggests temperature detrainment level, and consequently tropical clouds, will remain constant during climate change. constraint has implications for potential role in...

Abstract Liquid water path (LWP) mesoscale spatial variability in marine low cloud over the eastern subtropical oceans is examined using two months of daytime retrievals from Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA Terra satellite. Approximately 20 000 scenes size 256 km × are used analysis. It found that fraction strongly linked with LWP cloudy scene. shown here most cases variance dominated by horizontal scales 10–50 km, and increases as variance-containing scale...

The variability of the zonal-mean zonal wind in Southern Hemisphere is studied using EOF analysis and momentum budget diagnostics NCEP reanalysis data (1978–97). leading well separated from remaining EOFs represents north–south movement midlatitude jet. Analysis shows that a positive feedback between anomalies eddy fluxes accounts for unusual persistence EOF1 plays an important role selection variability. Further also propagating feedback, common to both EOF2, which responsible poleward...

Cloud feedback—the change in top‐of‐atmosphere radiative flux resulting from the cloud response to warming—constitutes by far largest source of uncertainty climate CO 2 forcing simulated global models ( GCMs ). We review main mechanisms for feedbacks, and discuss their representation sources intermodel spread. Global‐mean feedback results three effects: (1) rising free‐tropospheric clouds (a positive longwave effect); (2) decreasing tropical low amount shortwave [ SW ] (3) increasing...

Abstract Regional extratropical tropospheric variability in the North Pacific and eastern Europe is well correlated with Northern Hemisphere wintertime stratospheric polar vortex both ECMWF reanalysis record Whole Atmosphere Community Climate Model. To explain this correlation, link between vertical Eliassen–Palm flux analyzed. Simple reasoning shows that can deepen or flatten stationary waves, particular its wavenumber-1 -2 components, thus providing a physical explanation for correlation...

Longwave cloud feedback is systematically positive and nearly the same magnitude across all global climate models used in Intergovernmental Panel on Climate Change Fourth Assessment Report (AR4). Here it shown that this robust longwave caused large part by tendency for tropical high clouds to rise such a way as remain at temperature warms. Furthermore, response warming consistent with well‐known physics, specifically requirement that, equilibrium, tropospheric heating convection can only be...

Abstract Changes in the frequency and intensity of rainfall are an important potential impact climate change. Two modes change, a shift increase, applied to simulations global warming with models from phase 5 Coupled Model Intercomparison Project (CMIP5). The response CO2 doubling multimodel mean CMIP5 daily is characterized by increase 1% K−1 at all rain rates higher 3.3% K−1. In addition these some also show substantial highest called extreme mode warming. models, this can be shown...

Abstract It is shown from historical data and modeling experiments that a proximate cause of the cold winter in North America 2013–2014 was pattern sea surface temperature (SST) Pacific Ocean. Each three dominant modes SST variability connected to tropics has strong expression extratropical weather patterns. Beginning middle 2013, third mode two standard deviations positive remained so through January 2015. This associated with high pressure northeast low temperatures over central America. A...

This study proposes a novel technique for computing cloud feedbacks using histograms of fraction as joint function cloud-top pressure (CTP) and optical depth (τ). These were generated by the International Satellite Cloud Climatology Project (ISCCP) simulator that was incorporated into doubled-CO 2 simulations from 11 global climate models in Feedback Model Intercomparison Project. The authors use radiative transfer model to compute top atmosphere flux sensitivities perturbations each bin...

Models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) robustly predict that rate increase in global-mean precipitation with surface temperature is much less than water vapor. The goal this paper to explain detail mechanisms by which constrained radiative cooling. Changes clear-sky atmospheric cooling resulting changes and humidity global warming simulations are good agreement multimodel, projected GCMs (~1.1 W m−2 K−1). In an atmosphere fixed specific humidity, top (TOA)...

Atmospheric aerosols, suspended solid and liquid particles, act as nucleation sites for cloud drop formation, affecting clouds properties-ultimately influencing the dynamics, lifetime, water path, areal extent that determine reflectivity (albedo) of clouds. The concentration N d droplets in influences planetary albedo is sensitive to availability aerosol particles on which form. Natural concentrations affect not only properties themselves but also modulate sensitivity changes anthropogenic...

Cloud radiative kernels and histograms of cloud fraction, both as functions cloud-top pressure optical depth, are used to quantify amount, altitude, depth feedbacks. The analysis is applied doubled-CO 2 simulations from 11 global climate models in the Feedback Model Intercomparison Project. Global, annual, ensemble mean longwave (LW) shortwave (SW) feedbacks positive, with latter nearly twice large former. robust increase altitude tropics extratropics dominant contributor positive LW...

Abstract In this study, it is shown that CMIP5 global climate models (GCMs) convert supercooled water to ice at relatively warm temperatures tend have a greater mean‐state cloud fraction and more negative feedback in the middle high latitude Southern Hemisphere. We investigate possible reasons for these relationships by analyzing mixed‐phase parameterizations 26 GCMs. The atmospheric temperature where liquid are equally prevalent (T5050) used characterize parameterization each GCM. Liquid...

The leading modes of month-to-month variability in the Northern and Southern Hemispheres are examined by comparing a 100-yr run Geophysical Fluid Dynamics Laboratory GCM with NCEP–NCAR reanalyses observations. model simulation is control experiment which SSTs fixed to climatological annual cycle without any interannual variability. contain strong zonally symmetric or annular component that describes an expansion contraction polar vortex as midlatitude jet shifts equatorward poleward. This...

The Madden-Julian oscillation (MJO) is a large-scale episodic modulation of tropical winds and precipitation that travels eastward from Asia to America, with characteristic repeat time 30 60 days. Here it shown when MJO wind anomalies in the lower troposphere eastern Pacific are westerly, Gulf Mexico western Caribbean hurricane genesis four times more likely than easterly. Accurate predictions may lead improved long-range forecasts cyclone activity.

The atmosphere displays modes of variability whose structures exhibit a strong longitudinally symmetric (annular) component that extends from the surface to stratosphere in middle and high latitudes both hemispheres. In past 30 years, these have exhibited trends seem larger than their natural background variability, may be related human influences on stratospheric ozone and/or atmospheric greenhouse gas concentrations. pattern climate during few decades is marked by rapid cooling depletion...