On the effects of large-scale temperature advection in the Martian atmosphere

During the 2020 Mars opposition, we observe from Earth the occurrence of a non-typical large-scale high-altitude clouds system, extending over thousands of km from the equator to 50&#176;S. Over 3 hours, they emerge from the night side at an altitude of 90 (-15/+30) km and progressively dissipate in the dayside. They occur at a solar longitude of 316&#176;, west of the magnetic anomaly and concomitantly to a regional dust storm. Despite their high altitude, they are composed of relatively large particles, suggesting a probable CO2 ice composition, although H2O cannot be totally excluded. Such ice clouds were not reported previously. We discuss the formation of this new type of clouds and suggest a possible nucleation from cosmic particle precipitation.

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Compressed Python likelihood for large scale temperature and polarization from Planck

Physical Review D ◽

10.1103/physrevd.105.023518 ◽

2022 ◽

Vol 105 (2) ◽

Author(s):

Heather Prince ◽

Jo Dunkley

Keyword(s):

Large Scale ◽

Scale Temperature

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Large-Scale Temperature Changes Across the Southern Andes: 20th-Century Variations in the Context of the Past 400 Years

Advances in Global Change Research - Climate Variability and Change in High Elevation Regions: Past, Present & Future ◽

10.1007/978-94-015-1252-7_10 ◽

2003 ◽

pp. 177-232 ◽

Cited By ~ 26

Author(s):

Ricardo Villalba ◽

Antonio Lara ◽

José A. Boninsegna ◽

Mariano Masiokas ◽

Silvia Delgado ◽

...

Keyword(s):

20Th Century ◽

Large Scale ◽

Southern Andes ◽

Temperature Changes ◽

The Past ◽

Scale Temperature

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Design and Implementation of Large-Scale Temperature Stability Control System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.644-650.313 ◽

2014 ◽

Vol 644-650 ◽

pp. 313-316

Author(s):

Wen Lai Liu

Keyword(s):

Control System ◽

System Design ◽

Large Scale ◽

Control Method ◽

Temperature Stability ◽

Stability Control ◽

Control System Design ◽

Scale Temperature ◽

Stability Control System ◽

The Stability

large-scale temperature stability control method is studied in this paper. In the process of large-scale temperature control, the stability of control is a very important indicator. To this end, this paper proposes a large-scale temperature stability control algorithm based on hierarchical control method. Balance equation of large-scale temperature stability control is created for the effective transmission of control data. According to the constant control theory, large-scale temperature stability control system design is achieved. Experimental results show that the proposed algorithm for large-scale temperature stability control system design, can greatly improve the stability of control, and get the satisfactory results.

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Responses of Shallow Cumulus Convection to Large-Scale Temperature and Moisture Perturbations: A Comparison of Large-Eddy Simulations and a Convective Parameterization Based on Stochastically Entraining Parcels

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-11-0279.1 ◽

2012 ◽

Vol 69 (6) ◽

pp. 1936-1956 ◽

Cited By ~ 29

Author(s):

Ji Nie ◽

Zhiming Kuang

Keyword(s):

Large Scale ◽

Potential Temperature ◽

Large Eddy Simulations ◽

Cumulus Parameterization ◽

Temperature Perturbation ◽

Cumulus Convection ◽

Positive Temperature ◽

Shallow Cumulus ◽

Scale Temperature ◽

Large Eddy

Abstract Responses of shallow cumuli to large-scale temperature/moisture perturbations are examined through diagnostics of large-eddy simulations (LESs) of the undisturbed Barbados Oceanographic and Meteorological Experiment (BOMEX) case and a stochastic parcel model. The perturbations are added instantaneously and allowed to evolve freely afterward. The parcel model reproduces most of the changes in the LES-simulated cloudy updraft statistics in response to the perturbations. Analyses of parcel histories show that a positive temperature perturbation forms a buoyancy barrier, which preferentially eliminates parcels that start with lower equivalent potential temperature or have experienced heavy entrainment. Besides the amount of entrainment, the height at which parcels entrain is also important in determining their fate. Parcels entraining at higher altitudes are more likely to overcome the buoyancy barrier than those entraining at lower altitudes. Stochastic entrainment is key for the parcel model to reproduce the LES results. Responses to environmental moisture perturbations are quite small compared to those to temperature perturbations because changing environmental moisture is ineffective in modifying buoyancy in the BOMEX shallow cumulus case. The second part of the paper further explores the feasibility of a stochastic parcel–based cumulus parameterization. Air parcels are released from the surface layer and temperature/moisture fluxes effected by the parcels are used to calculate heating/moistening tendencies due to both cumulus convection and boundary layer turbulence. Initial results show that this conceptually simple parameterization produces realistic convective tendencies and also reproduces the LES-simulated mean and variance of cloudy updraft properties, as well as the response of convection to temperature/moisture perturbations.

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Comments on “Reconstruction of the Extratropical NH Mean Temperature over the Last Millennium with a Method That Preserves Low-Frequency Variability”

Journal of Climate ◽

10.1175/jcli-d-11-00404.1 ◽

2012 ◽

Vol 25 (22) ◽

pp. 7991-7997 ◽

Cited By ~ 10

Author(s):

Anders Moberg

Keyword(s):

Large Scale ◽

Low Frequency ◽

Temperature Reconstruction ◽

Noise Variance ◽

Low Frequencies ◽

Scale Temperature ◽

Low Frequency Variability ◽

High Frequency Variability ◽

Frequency Temperature ◽

Correct Estimate

Abstract Christiansen and Ljungqvist have presented an extratropical NH temperature reconstruction using a method (LOC) that they claim “preserves” low-frequency variability, at the expense of exaggerated high-frequency variability. Using theoretical arguments and a pseudoproxy experiment, it is demonstrated here that the LOC method is not guaranteed to preserve variability at any frequency. Rather, LOC reconstructions will have more variance than true large-scale temperature averages at all frequencies. This variance inflation, however, can be negligible at those frequencies where the noise variance in individual proxies is small enough to be effectively cancelled when computing an average over the available proxies. Because the proxy noise variance at low frequencies cannot be directly estimated, and thus has to be regarded as unknown, it is safer to regard a reconstruction with the LOC method as providing an estimate of the upper bound of the large-scale low-frequency temperature variability rather than one with a correct estimate of this variance.

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