scholarly journals Using the UM dynamical cores to reproduce idealised 3-D flows

2013 ◽  
Vol 6 (3) ◽  
pp. 3681-3741 ◽  
Author(s):  
N. J. Mayne ◽  
I. Baraffe ◽  
D. M. Acreman ◽  
C. Smith ◽  
N. Wood ◽  
...  
Keyword(s):  
Large Scale ◽  
Circulation Model ◽  
Test Case ◽  
Global Circulation Model ◽  
Dynamical Equations ◽  
Present Evidence ◽  
Global Circulation ◽  
The Uk ◽  
Tidally Locked Earth

Abstract. We demonstrate that both the current (New Dynamics), and next generation (ENDGame) dynamical cores of the UK Met Office global circulation model, the UM, reproduce consistently, the long-term, large-scale flows found in several published idealised tests. The cases presented are the Held–Suarez test, a simplified model of Earth (including a stratosphere), and a model of a hypothetical Tidally Locked Earth (TLE). Furthermore, we show that using simplifications to the dynamical equations, which are expected to be justified for the physical domains and flow regimes we have studied, and which are supported by the ENDGame dynamical core, also produces matching long-term, large-scale flows. Finally, we present evidence for differences in the detail of the planetary (meridional) flows and circulations resulting from improvements in the ENDGame formulation over New Dynamics. Specifically, we find greater symmetry in the meridional circulations of the Tidally Locked Earth test case using the ENDGame formulation, which is a better match to our physical expectations of the flow for such a slowly rotating Earth-like system.

scholarly journals Using the UM dynamical cores to reproduce idealised 3-D flows

2014 ◽  
Vol 7 (6) ◽  
pp. 3059-3087 ◽  
Author(s):  
N. J. Mayne ◽  
I. Baraffe ◽  
D. M. Acreman ◽  
C. Smith ◽  
N. Wood ◽  
...  
Keyword(s):  
Large Scale ◽  
Circulation Model ◽  
Simplified Model ◽  
Global Circulation Model ◽  
Dynamical Equations ◽  
Present Evidence ◽  
Global Circulation ◽  
The Uk ◽  
Tidally Locked Earth

Abstract. We demonstrate that both the current (New Dynamics), and next generation (ENDGame) dynamical cores of the UK Met Office global circulation model, the UM, reproduce consistently, the long-term, large-scale flows found in several published idealised tests. The cases presented are the Held–Suarez test, a simplified model of Earth (including a stratosphere), and a hypothetical tidally locked Earth. Furthermore, we show that using simplifications to the dynamical equations, which are expected to be justified for the physical domains and flow regimes we have studied, and which are supported by the ENDGame dynamical core, also produces matching long-term, large-scale flows. Finally, we present evidence for differences in the detail of the planetary flows and circulations resulting from improvements in the ENDGame formulation over New Dynamics.

scholarly journals Atmospheric dynamics on tidally locked Earth-like planets in the habitable zone of an M dwarf star

2013 ◽  
Vol 8 (S299) ◽  
pp. 376-377 ◽  
Author(s):  
Ludmila Carone ◽  
Rony Keppens ◽  
Leen Decin
Keyword(s):  
Atmospheric Circulation ◽  
Large Scale ◽  
Rotation Period ◽  
Circulation Model ◽  
Return Flow ◽  
Parameter Study ◽  
Global Circulation Model ◽  
Dwarf Star ◽  
Global Circulation ◽  
M Dwarf

AbstractWe investigated the large scale atmospheric circulation of Gl581g, a potentially habitable planet around an M dwarf star, using an idealized dry global circulation model (GCM) with simplified thermal forcing as a first step towards a systematic extended parameter study. The results are compared with the work of Joshi et al. (1997) who investigated a tidally-locked habitable Earth analogue with less than half the rotation period of Gl581g. The extent, form and strength of the atmospheric circulation in each model generally agree with each other, even though the models differ in key parameters such as planetary radius, surface gravity, forcing scheme and rotation period. The substellar point is associated with an uprising direct circulation-branch of a Hadley-like cell with return flow over the poles. It is compelling to assume that the substellar point of a tidally locked terrestrial exoplanet behaves dynamically like the Earth's tropic associated with clouds and precipitation, making it an ideal target for habitability.

Downscaling of GCM forecasts to streamflow over Scandinavia

2008 ◽  
Vol 39 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Patrik Nilsson ◽  
Cintia B. Uvo ◽  
Willem A. Landman ◽  
Tinh D. Nguyen
Keyword(s):  
Large Scale ◽  
Circulation Model ◽  
Model Output ◽  
Northern Sweden ◽  
Global Circulation Model ◽  
Global Circulation ◽  
Principal Source ◽  
Streamflow Forecasts ◽  
Linear Neural Network ◽  
Model Output Statistics

A seasonal forecasting technique to produce probabilistic and deterministic streamflow forecasts for 23 basins in Norway and northern Sweden is developed in this work. Large scale circulation and moisture fields, forecasted by the ECHAM4.5 model 4 months in advance, are used to forecast spring flows. The technique includes model output statistics (MOS) based on a non-linear Neural Network (NN) approach. Results show that streamflow forecasts from Global Circulation Model (GCM) predictions, for the Scandinavia region are viable and highest skill values were found for basins located in south-western Norway. The physical interpretation of the forecasting skill is that stations close to the Norwegian coast are directly exposed to prevailing winds from the Atlantic Ocean, which constitute the principal source of predictive information from the atmosphere on the seasonal timescale.

scholarly journals The UK Met Office global circulation model with a sophisticated radiation scheme applied to the hot Jupiter HD 209458b

2016 ◽  
Vol 595 ◽  
pp. A36 ◽  
Author(s):  
David S. Amundsen ◽  
Nathan J. Mayne ◽  
Isabelle Baraffe ◽  
James Manners ◽  
Pascal Tremblin ◽  
...  
Keyword(s):  
Circulation Model ◽  
Global Circulation Model ◽  
Global Circulation ◽  
The Uk ◽  
Radiation Scheme ◽  
Hot Jupiter

How well does a 1/4° global circulation model simulate large-scale oceanic observations?

1996 ◽  
Vol 101 (C11) ◽  
pp. 25779-25811 ◽  
Author(s):  
Detlef Stammer ◽  
Robin Tokmakian ◽  
Albert Semtner ◽  
Carl Wunsch
Keyword(s):  
Large Scale ◽  
Circulation Model ◽  
Global Circulation Model ◽  
Global Circulation

scholarly journals Seasonal predictability of the 2010 Russian heat wave

2013 ◽  
Vol 1 (5) ◽  
pp. 5057-5086 ◽  
Author(s):  
P. Katsafados ◽  
A. Papadopoulos ◽  
G. Varlas ◽  
E. Papadopoulou ◽  
E. Mavromatidis
Keyword(s):  
Heat Wave ◽  
Large Scale ◽  
Initial Conditions ◽  
Circulation Model ◽  
Global Circulation Model ◽  
Atmospheric Blocking ◽  
Seasonal Predictability ◽  
Global Circulation ◽  
Seasonal Time Scale ◽  
The Impact

Abstract. The prevailed atmospheric blocking over Eastern Europe and Western Russia during July and August 2010 led in the development of the devastating Russian heat wave. Therefore the question whether the event was predictable or not is highly important. The principal aim of this study is to examine the predictability of this high-impact atmospheric event on a seasonal time scale. To this end, a set of dynamical seasonal simulations have been carried out using an Atmospheric Global Circulation Model (AGCM). The impact of various model initializations on the predictability of this large scale event and its sensitivity to the initial conditions has been also investigated. Ensemble seasonal simulations indicated that only a few individual members reproduced the main features of the blocking system 3 months ahead. Most members missed the phase space and the velocity of the system setting limitations in the predictability of the event.

scholarly journals HAPEX-Sahel: a large-scale study of land-atmosphere interactions in the semi-arid tropics

1994 ◽  
Vol 12 (1) ◽  
pp. 53-64 ◽  
Author(s):  
J.-P. Goutorbe ◽  
T. Lebel ◽  
A. Tinga ◽  
P. Bessemoulin ◽  
J. Brouwer ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Land Surface ◽  
Large Scale ◽  
Transition Period ◽  
Circulation Model ◽  
Global Circulation Model ◽  
Global Circulation ◽  
Experimental Strategy ◽  
Aggregation Techniques ◽  
Intensive Observation

Abstract. The Hydrologic Atmospheric Pilot EXperiment in the Sahel (HAPEX-Sahel) was carried out in Niger, West Africa, during 1991 - 1992, with an intensive observation period (IOP) in August - October 1992. It aims at improving the parameterization of land surface atmosphere interactions at the Global Circulation Model (GCM) gridbox scale. The experiment combines remote sensing and ground based measurements with hydrological and meteorological modelling to develop aggregation techniques for use in large scale estimates of the hydrological and meteorological behaviour of large areas in the Sahel. The experimental strategy consisted of a period of intensive measurements during the transition period of the rainy to the dry season, backed up by a series of long term measurements in a 1° by 1° square in Niger. Three "supersites" were instrumented with a variety of hydrological and (micro) meteorological equipment to provide detailed information on the surface energy exchange at the local scale. Boundary layer measurements and aircraft measurements were used to provide information at scales of 100 - 500 km2. All relevant remote sensing images were obtained for this period. This programme of measurements is now being analyzed and an extensive modelling programme is under way to aggregate the information at all scales up to the GCM grid box scale. The experimental strategy and some preliminary results of the IOP are described.

scholarly journals Seasonal predictability of the 2010 Russian heat wave

2014 ◽  
Vol 14 (6) ◽  
pp. 1531-1542 ◽  
Author(s):  
P. Katsafados ◽  
A. Papadopoulos ◽  
G. Varlas ◽  
E. Papadopoulou ◽  
E. Mavromatidis
Keyword(s):  
Heat Wave ◽  
Lead Time ◽  
Large Scale ◽  
Initial Conditions ◽  
Circulation Model ◽  
Global Circulation Model ◽  
Atmospheric Blocking ◽  
Seasonal Predictability ◽  
Global Circulation ◽  
The Impact

Abstract. The atmospheric blocking over eastern Europe and western Russia that prevailed during July and August of 2010 led to the development of a devastating Russian heat wave. Therefore the question of whether the event was predictable or not is highly important. The principal aim of this study is to examine the predictability of this high-impact atmospheric event on a seasonal timescale. To this end, a set of dynamical seasonal simulations have been carried out using an atmospheric global circulation model (AGCM). The impact of various model initializations on the predictability of this large-scale event and its sensitivity to the initial conditions has been also investigated. The ensemble seasonal simulations are based on a modified version of the lagged-average forecast method using different lead-time initializations of the model. The results indicated that only a few individual members reproduced the main features of the blocking system 3 months ahead. Most members missed the phase space and the propagation of the system, setting limitations in the predictability of the event.

Sign in / Sign up

Export Citation Format

Share Document