The ECMWF medium-range prediction models development of the numerical formulations and the impact of increased resolution

Simmons, A. J.; Burridge, D. M.; Jarraud, M.; Girard, Claude; Wergen, Werner

doi:10.1007/bf01027467

Cited by 229 publications

(139 citation statements)

References 27 publications

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“…Another example of differences in simulation which can be attributed solely to numerical methods is given by Simmons et al (1989). It would require further experimentation to determine unambiguously the mechanisms by which the differences in numerical techniques result in the observed differences of the tropical intraseasonal oscillations.…”

Section: Discussionmentioning

confidence: 99%

An Evaluation of the Structure of Tropical Intraseasonal Oscillations in Three General Circulation Models

Park

Straus

Lau

1990

Journal of the Meteorological Society of Japan

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Low-frequency oscillations appearing in three GCM seasonal cycle integrations are compared with the analyses of the European Centre for Medium-Range Weather Forecasts (ECMWF). All three models have the same resolution: 4 degrees latitude by 5 degrees longitude, with 9 levels. The GLAS GCM simulates a realistic eastward propagation of the 30-60 day oscillation in the tropical upperlevel divergent flow. The eastward travelling planetary scale structure becomes more stationary over the Indonesian region and accelerates over the central Pacific, as observed. In the GLA GCM, the oscillation propagates into the higher latitudes of both hemispheres as the waves leave the convective region. The presence of the eastward propagating oscillation is not obvious in the UCLA GCM. The wavenumber-frequency spectra of the 200 mb velocity potential reveal that all the GCMs have a significantly weaker signal for eastward propagation in the 30-60 day range than the analyses. The spectrum for the GLAS GCM is dominated by 20-60 day periods, while the GLA GCM has a spectral peak around 20-30 days. There is a weak eastward propagating peak near 15 days in the UCLA GCM. The dominant phase speeds and the different vertical structures of the heating profiles in the GCMs are in general agreement with current theory involving the positive feedback between latent heating and moist static stability.The composited patterns of the observations indicate that in the tropics a Kelvin wave-type structure is dominant near the center of the oscillation. The simulated winds are fairly realistic, although the meridional component is too strong, especially in the GLA GCM. The vertical structures of the zonal wind component and moisture suggest that a mobile wave-CISK (Lau and Peng,1987) is an important mechanism in maintaining the intraseasonal oscillation in these GCMs. The vertical distribution of the moisture field further suggests that evaporation-wind feedback (Neelin, et al., 1987) may play a role in maintaining the eastward propagating tropical waves. The differences in the structure of the oscillation in the GLAS GCM and GLA GCM appear to be a consequence of the different numerical schemes used. The GCMs have preferred zones for diabatic heating, with a turn-on heating occurring when the rising branch of the intraseasonal oscillation passes over these convective regions.All three GCMs fail to capture the detailed evolution in the different stages of the development and decay of the oscillation. The results suggest that an improvement in the boundary layer moisture processes may be crucial for a better simulation of the oscillation.

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Section: Discussionmentioning

confidence: 99%

An Evaluation of the Structure of Tropical Intraseasonal Oscillations in Three General Circulation Models

Park

Straus

Lau

1990

Journal of the Meteorological Society of Japan

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“…De-tided timeseries were reviewed and surge residuals exceeding 0.5 m were considered as major surge events. The isolated surges were then hindcast by the model, forced from two 8 atmospheric datasets: regional reanalysis ERA-40 data (Uppala et al 2005) for the period 1959-1991 and operational model level first-guess data (Simmons et al 1989) from year 1991 onwards. These datasets were obtained from the European Centre for Medium-Range Weather Forecasts (ECMWF) and consisted of mean sea level pressure and 10 m wind fields at 3-hour temporal resolution.…”

Section: Numerical Model Set-up and Simulation Periodmentioning

confidence: 99%

Tide–surge interactions and their effects on total sea levels in Irish coastal waters

2013

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“…[10] ECHAM5 is a GCM developed at the Max Planck Institute for Meteorology based on the numerical weather prediction model of the European Center for Medium-Range Weather Forecast (ECMWF) [Simmons et al, 1989]. The prognostic variables of the model are vorticity, divergence, temperature, and surface pressure and are represented in the horizontal by truncated series of spherical harmonics.…”

Section: Echam5 General Circulation Modelmentioning

confidence: 99%

Trace gas and aerosol interactions in the fully coupled model of aerosol‐chemistry‐climate ECHAM5‐HAMMOZ: 1. Model description and insights from the spring 2001 TRACE‐P experiment

et al. 2008

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[1] In this paper, we introduce the ECHAM5-HAMMOZ aerosol-chemistry-climate model that includes fully interactive simulations of Ox-NOx-hydrocarbons chemistry and of aerosol microphysics (including prognostic size distribution and mixing state of aerosols) implemented in the General Circulation Model ECHAM5. The photolysis rates used in the gas chemistry account for aerosol and cloud distributions and a comprehensive set of heterogeneous reactions is implemented. The model is evaluated with trace gas and aerosol observations provided by the TRACE-P aircraft experiment. Sulfate concentrations are well captured but black carbon concentrations are underestimated. The number concentrations, surface areas, and optical properties are reproduced fairly well near the surface but underestimated in the upper troposphere. CO concentrations are well reproduced in general while O 3 concentrations are overestimated by 10-20 ppbv. We find that heterogeneous chemistry significantly influences the regional and global distributions of a number of key trace gases. Heterogeneous reactions reduce the ozone surface concentrations by 18-23% over the TRACE-P region and the global annual mean O 3 burden by 7%. The annual global mean OH concentration decreases by 10% inducing a 7% increase in the global CO burden. Annual global mean HNO 3 surface concentration decreases by 15% because of heterogenous reaction on mineral dust. A comparison of our results to those from previous studies suggests that the choice of uptake coefficients for a given species is the critical parameter that determines the global impact of heterogeneous chemistry on a trace gas (rather than the description of aerosol properties and distributions). A prognostic description of the size distribution and mixing state of the aerosols is important, however, to account for the effect of heterogeneous chemistry on aerosols as further discussed in the second part of this two-part series.Citation: Pozzoli, L., I. Bey, S. Rast, M. G. Schultz, P. Stier, and J. Feichter (2008), Trace gas and aerosol interactions in the fully coupled model of aerosol-chemistry-climate ECHAM5-HAMMOZ: 1. Model description and insights from the spring 2001 TRACE-P experiment,

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The ECMWF medium-range prediction models development of the numerical formulations and the impact of increased resolution

Cited by 229 publications

References 27 publications

An Evaluation of the Structure of Tropical Intraseasonal Oscillations in Three General Circulation Models

An Evaluation of the Structure of Tropical Intraseasonal Oscillations in Three General Circulation Models

Tide–surge interactions and their effects on total sea levels in Irish coastal waters

Trace gas and aerosol interactions in the fully coupled model of aerosol‐chemistry‐climate ECHAM5‐HAMMOZ: 1. Model description and insights from the spring 2001 TRACE‐P experiment

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