One-dimensional site-specific forecasting of radiation fog. Part I: Model formulation and idealised sensitivity studies

2001 ◽  
Vol 8 (3) ◽  
pp. 279-286 ◽  
Author(s):  
P A Clark ◽  
W P Hopwood
Keyword(s):  
Model Formulation ◽  
Radiation Fog ◽  
Site Specific ◽  
One Dimensional ◽  
Sensitivity Studies

scholarly journals Sensitivity studies of the recent new data on O(<sup>1</sup><i>D</i>) quantum yields in O<sub>3</sub> Hartley band photolysis in the stratosphere

2003 ◽  
Vol 3 (3) ◽  
pp. 2331-2352 ◽  
Author(s):  
N. Taniguchi ◽  
S. Hayashida ◽  
K. Takahashi ◽  
Y. Matsumi
Keyword(s):  
Atmospheric Chemistry ◽  
Atmospheric Model ◽  
Quantum Yields ◽  
Oh Radicals ◽  
One Dimensional ◽  
Near Ultraviolet ◽  
Steady State Model ◽  
Sensitivity Studies ◽  
Hartley Band ◽  
Excited Oxygen

Abstract. The production yields of excited oxygen O(1D) atoms from the near ultraviolet O3 photolysis are essential quantities for atmospheric chemistry calculations because of its importance as major sources of hydroxyl (OH) radicals and nitric oxide (NO). Recently, new O(1D) quantum yields from O3 photolysis between 230 and 305 nm in the Hartley band region were reported, which are almost independent of the photolysis wavelength (0.88-0.93) and smaller than NASA/JPL-2000 recommendation (0.95 between 240 and 300 nm). In order to assess consequences of the new data of O(1D) quantum yields on the stratospheric chemistry, the changes in stratospheric chemical partitioning and O3 concentration are examined using a one-dimensional atmospheric model. Our steady state model simulations for mid-latitude in March indicate that the smaller O(1D) quantum yields result in increases of stratospheric O3 (up to ~2% in the upper stratosphere), which are attributed to the changes in HOx, NOx, and ClOx abundance and their catalyzed O3 loss rates.

The Use of Dual-Number-Automatic-Differentiation With Sensitivity Analysis to Investigate Physical Models

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Malcolm J. Andrews
Keyword(s):  
Automatic Differentiation ◽  
Liquid Droplet ◽  
Free Fall ◽  
Physical Models ◽  
Test Problems ◽  
One Dimensional ◽  
Physical Systems ◽  
Dual Number ◽  
Functional Forms ◽  
Sensitivity Studies

Local sensitivities are explored using dual-number-automatic-differentiation (DNAD) across three mathematical models of physical systems that have increasing complexity. The models are: (1) a model for the approach of a sphere to free fall; (2) the Taylor-analogy-breakup (TAB) model for liquid droplet atomization; and, (3) an evaluation of the BHR model of turbulence for the development of one-dimensional Rayleigh–Taylor driven material mixing. Sensitivity and functional shape parameters are developed that permit a relative study to be quickly performed for each model. Furthermore, compensating errors, measurement parameter sensitivity, and feature sensitivities are investigated. The test problems consider transient (initial condition effects), steady state (final functional forms), and measures of functional shape. Reduced model forms are explored and selected according to sensitivity. Aside from the local sensitivity studies of the models and associated results, DNAD is shown to be one of several useful, quickly implemented tools to investigate a variety of sensitivity effects in models and together with the present results may serve as a means to simplify a model or focus future model developments and associated experiments.

scholarly journals Sensitivity studies of the recent new data on O(<sup>1</sup><i>D</i>) quantum yields in O<sub>3</sub> Hartley band photolysis in the stratosphere

2003 ◽  
Vol 3 (5) ◽  
pp. 1293-1300 ◽  
Author(s):  
N. Taniguchi ◽  
S. Hayashida ◽  
K. Takahashi ◽  
Y. Matsumi
Keyword(s):  
Atmospheric Chemistry ◽  
Atmospheric Model ◽  
Quantum Yields ◽  
Oh Radicals ◽  
One Dimensional ◽  
Near Ultraviolet ◽  
Steady State Model ◽  
Sensitivity Studies ◽  
Hartley Band ◽  
Excited Oxygen

Abstract. The production yields of excited oxygen O(1D) atoms from the near ultraviolet O3 photolysis are essential quantities for atmospheric chemistry calculations because of its importance as major sources of hydroxyl (OH) radicals and nitric oxide (NO). Recently, new O(1D) quantum yields from O3 photolysis between 230 and 305 nm in the Hartley band region were reported, which are almost independent of the photolysis wavelength (0.88-0.93) and smaller than NASA/JPL-2000 recommendations (0.95 between 240 and 300 nm). In order to assess consequences of the new data of O(1D) quantum yields on the stratospheric chemistry, the changes in stratospheric chemical partitioning and O3 concentration are examined using a one-dimensional atmospheric model. Our steady state model simulations for 40° N in March indicate that the smaller O(1D) quantum yields result in increases of stratospheric O3 (up to ~2% in the upper stratosphere), which are attributed to the changes in HOx, NOx, and ClOx abundance and their catalyzed O3 loss rates.

scholarly journals Climate bistability of Earth-like exoplanets

2019 ◽  
Vol 492 (2) ◽  
pp. 2638-2650
Author(s):  
Giuseppe Murante ◽  
Antonello Provenzale ◽  
Giovanni Vladilo ◽  
Giuliano Taffoni ◽  
Laura Silva ◽  
...  
Keyword(s):  
Large Fraction ◽  
Temperature Model ◽  
One Dimensional ◽  
Planet Surface ◽  
The Earth ◽  
Exoplanetary Systems ◽  
Stellar Radiation ◽  
Sensitivity Studies ◽  
Earth’S Climate ◽  
Orbital Axis

ABSTRACT Before about 500 million years ago, most probably our planet experienced temporary snowball conditions, with continental and sea ices covering a large fraction of its surface. This points to a potential bistability of Earth’s climate that can have at least two different (statistical) equilibrium states for the same external forcing (i.e. solar radiation). Here, we explore the probability of finding bistable climates in Earth-like exoplanets and consider the properties of planetary climates obtained by varying the semimajor orbital axis (thus, received stellar radiation), eccentricity and obliquity, and atmospheric pressure. To this goal, we use the Earth-like planet surface temperature model (ESTM), an extension of one-dimensional Energy Balance Models developed to provide a numerically efficient climate estimator for parameter sensitivity studies and long climatic simulations. After verifying that the ESTM is able to reproduce Earth climate bistability, we identify the range of parameter space where climate bistability is detected. An intriguing result of this work is that the planetary conditions that support climate bistability are remarkably similar to those required for the sustenance of complex, multicellular life on the planetary surface. The interpretation of this result deserves further investigation, given its relevance for the potential distribution of life in exoplanetary systems.

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