Trends in the Airglow Temperatures in the MLT Region—Part 2: SABER Observations and Comparisons to Model Simulations

The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperature measurements at low latitudes from 89 km to 97 km were used to derive the F10.7 and Ap index trends, and the trends were compared to model simulations. The annual mean nonzonal (e.g., at the model simulation location at 18° N, 290° E) SABER temperature showed a good-to-moderate correlation with F10.7, with a trend of 4.5–5.3 K/100 SFU, and a moderate-to-weak correlation with the Ap index, with a trend of 0.1–0.3 K/nT. The annual mean zonal mean SABER temperature was found to be highly correlated with the F10.7, with a similar trend, and moderately correlated with the Ap index, with a trend in a similar range. The correlation with the Ap index was significantly improved with a slightly larger trend when the zonal mean temperature was fitted with a 1-year backward shift in the Ap index. The F10.7 (Ap index) trends in the simulated O2 and the O(1S) temperature were smaller (larger) than those in the annual mean nonzonal mean SABER temperature. The trends from the simulations were better compared to those in the annual mean zonal mean temperature. The comparisons were even better when compared to the trend results obtained from fitting with a backward shift in the Ap index.

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Trends in the Airglow Temperatures in the MLT Region—Part 3: Ground-Based and SABER Measurements

Atmosphere ◽

10.3390/atmos12091161 ◽

2021 ◽

Vol 12 (9) ◽

pp. 1161

Author(s):

Tai-Yin Huang ◽

Michael Vanyo

Keyword(s):

Trend Analysis ◽

Full Range ◽

Temperature Measurements ◽

Moderate Correlation ◽

Meteor Radar ◽

Weak Correlation ◽

Broadband Emission ◽

Time Periods ◽

Ap Index ◽

Mlt Region

Ground-based temperature measurements at Svalbard, Wuppertal, and Hohenpeissenberg were analyzed to obtain F10.7, Ap index, and Dst index trends. The trends were then compared to those obtained from Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperature measurements at the same locations. Trend analysis was carried out for overlapped time periods, full range of available data, and the CO2-detrended full range of available data. The Svalbard meteor radar (SABER) temperature showed a weak (moderate) correlation with F10.7 and a moderate (weak) correlation with Ap and Dst indices. The trends in the Wuppertal OH* temperature compare well with the SABER temperature when a full range of data is used in the analysis. Both temperatures had a similar F10.7 trend with the same level of correlation coefficient. The F10.7 trend in the Hohenpeissenberg OH* temperature compared well with that obtained by SABER, but the former displayed a weak correlation. The Hohenpeissenberg data displayed a very weak correlation with Ap and Dst indices. Our study clearly shows that a longer dataset would better capture trends in temperature, as was evidenced by the results of Wuppertal data. The CO2-detrended temperatures overall showed slightly larger trend values with a slightly better correlation.

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Trends in the Airglow Temperatures in the MLT Region—Part 1: Model Simulations

Atmosphere ◽

10.3390/atmos11050468 ◽

2020 ◽

Vol 11 (5) ◽

pp. 468

Author(s):

Tai-Yin Huang ◽

Michael Vanyo

Keyword(s):

Geomagnetic Activity ◽

Linear Trend ◽

Lower Thermosphere ◽

Solar Cycle Variation ◽

Temperature Variations ◽

Co2 Gas ◽

Ap Index ◽

Highly Correlated ◽

Airglow Intensity ◽

Mlt Region

Airglow intensity-weighted temperature variations induced by the CO2 increase, solar cycle variation (F10.7 as a proxy) and geomagnetic activity (Ap index as a proxy) in the Mesosphere and Lower Thermosphere (MLT) region were simulated to quantitatively assess their influences on airglow temperatures. Two airglow models, MACD-00 and OHCD-00, were used to simulate the O(1S) greenline, O2(0,1) atmospheric band, and OH(8,3) airglow temperature variations induced by these influences to deduce the trends. Our results show that all three airglow temperatures display a linear trend of ~−0.5 K/decade, in response to the increase of CO2 gas concentration. The airglow temperatures were found to be highly correlated with Ap index, and moderately correlated with F10.7, with the OH temperature showing an anti-correlation. The F10.7 and Ap index trends were found to be ~−0.7 ± 0.28 K/100SFU and ~−0.1 ± 0.02 K/nT in the OH temperature, 4.1 ± 0.7 K/100SFU and ~0.6 ± 0.03 K/nT in the O2 temperature and ~2.0 ± 0.6 K/100SFU and ~0.4 ± 0.03 K/nT in the O1S temperature. These results indicate that geomagnetic activity can have a rather significant effect on the temperatures that had not been looked at previously.

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Response of Poinsettia Growth and Development to Ratio of Radiant to Thermal Energy

HortScience ◽

10.21273/hortsci.33.3.508e ◽

1998 ◽

Vol 33 (3) ◽

pp. 508e-508

Author(s):

Bin Liu ◽

Royal D. Heins

Keyword(s):

Plant Growth ◽

Thermal Energy ◽

Growth And Development ◽

Model Simulation ◽

Interactive Effect ◽

Dry Weight ◽

Plant Spacing ◽

Plant Growth And Development ◽

Daily Light Integral ◽

Highly Correlated

A concept of ratio of radiant to thermal energy (RRT) has been developed to deal with the interactive effect of light and temperature on plant growth and development. This study further confirms that RRT is a useful parameter for plant growth, development, and quality control. Based on greenhouse experiments conducted with 27 treatment combinations of temperature, light, and plant spacing, a model for poinsettia plant growth and development was constructed using the computer program STELLA II. Results from the model simulation with different levels of daily light integral, temperature, and plant spacing showed that the RRT significantly affects leaf unfolding rate when RRT is lower than 0.025 mol/degree-day per plant. Plant dry weight is highly correlated with RRT; it increases linearly as RRT increases.

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HYDRODYNAMIC MODELLING IN INSHORE REEF AREA WITHIN KUANTAN COASTAL REGION

Journal CleanWAS ◽

10.26480/jcleanwas.01.2020.01.07 ◽

2020 ◽

Vol 4 (1) ◽

pp. 01-07

Author(s):

Muhammad Faiz Mohd Hanapiah ◽

Shahbudin Saad ◽

Zuhairi Ahmad

Keyword(s):

Model Simulation ◽

Coastal Region ◽

Flow Speed ◽

Current Speed ◽

Benthic Organism ◽

Reef Area ◽

Inshore Reef ◽

Highly Correlated ◽

The Impact ◽

Current Circulation

Current circulation provides major transport mechanism especially for benthic organism in the ocean. The present study described current circulation in inshore reef area within Kuantan coastal region by applying a numerical modelling of MIKE 21 Flow Model FM software. Model simulation produced good outcomes when compared with field data measurement with root mean square error (RMSE) for surface elevation, current speed and direction were below 20. Results also clearly indicated that current speed in inshore reef area was highly correlated with local tidal pattern in which higher flow speed were observed during high tides compared to low tide. Contrary to previous belief, our results clearly show the prevalence of tidal forcing in shaping current flow pattern in the study area since the impact of wind forcing was minimal during different monsoon seasons. This study gave new insight into how local tidal properties can regulate hydrodynamic pattern especially in fine-scale inshore reef area.

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Long-term Lidar Observations of the Gravity Wave Activity near the Mesopause at Arecibo

10.5194/acp-2018-731 ◽

2018 ◽

Author(s):

Xianchang Yue ◽

Jonathan S. Friedman ◽

Qihou Zhou ◽

Xiongbin Wu ◽

Jens Lautenbach

Keyword(s):

Potential Energy ◽

Gravity Wave ◽

Inversion Layer ◽

Lower Thermosphere ◽

Temperature Inversion ◽

Temperature Structure ◽

Mean Temperature ◽

The Mean ◽

Highly Correlated ◽

Lidar Observations

Abstract. 11-years long K Doppler lidar observations of temperature profiles in the mesosphere and lower thermosphere (MLT) between 85 and 100 km, conducted at the Arecibo Observatory, Puerto Rico (18.35° N, 66.75° W), are used to estimate seasonal variations of the mean temperature, the squared Brunt-Väisälä frequency, and the gravity wave potential energy in a composite year. The following unique features are obtained: (1) The mean temperature structure shows similar characteristics as a prior report based on a smaller dataset: (2) The profiles of the squared Brunt-Väisälä frequency usually reach the maxima at or just below the temperature inversion layer when that layer is present. The first complete range-resolved climatology of potential energy of temperature fluctuations in the tropical MLT exhibits an altitude dependent combination of annual oscillation (AO) and semiannual oscillation (SAO). Between 88 to 96 km altitude, the amplitudes of AO and SAO are comparable, and their phases are almost the same and quite close to day of year (DOY) 100. Below 88 km, the SAO amplitude is significantly larger than AO and the AO phase shifts to DOY 200 and after. At 97 to 98 km altitude, the amplitudes of AO and SAO reach their minima, and both phases shift significantly. Above that, the AO amplitude becomes greater. The annual mean potential energy profile reaches the minimum at 91 to 92 km altitude. The altitude-dependent SAO of the potential energy is found to be highly correlated with the satellite observed mean zonal winds reported in the literature.

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WRF Model Simulations of the Influence of the Athabasca Oil Sands Development on Convective Storms

Earth Interactions ◽

10.1175/ei-d-17-0013.1 ◽

2018 ◽

Vol 22 (3) ◽

pp. 1-25 ◽

Cited By ~ 1

Author(s):

Daniel Brown ◽

Gerhard Reuter

Keyword(s):

Land Surface ◽

Oil Sands ◽

Waste Heat ◽

Model Simulation ◽

Wrf Model ◽

Initiation Time ◽

Athabasca Oil Sands ◽

Model Simulations ◽

Surface Disturbance

Abstract The Athabasca oil sands development has created a land surface disturbance of almost 900 km2 in northeastern Alberta. Both through industrial processes and the removal of boreal forest vegetation, this surface disturbance impacts meteorology in the vicinity by releasing waste heat, raising the surface temperature, and lowering the surface humidity. To investigate the effects of the Athabasca oil sands development on thunderstorm intensity, initiation time, and duration, the Weather Research and Forecasting (WRF) Model was employed to simulate the effect of the surface disturbance on atmospheric conditions on 10 case study days. The results suggested the oil sands surface disturbance was not associated with substantial increases in thunderstorm intensity on any of the case study days. On two case study days, however, the WRF Model simulations differed substantially from the observed meteorological conditions and only approached the observations when the oil sands surface disturbance was included in the model simulation. Including the oil sands surface disturbance in the model simulations resulted in thunderstorm initiation about 2 h earlier and increased thunderstorm duration. Data from commercial aircraft showed that the 850–500-mb temperature difference was greater than 30°C (very unstable) only on these 2 days. Such cases are sufficiently rare that they are not expected to affect the overall thunderstorm climatology. Still, in these very unstable cases, the oil sands development appears to have a significant effect on thunderstorm initiation time and duration.

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Climatic records and linkage along an altitudinal gradient in the southern slope of Nepal Himalaya

Journal of Nepal Geological Society ◽

10.3126/jngs.v53i0.23804 ◽

2017 ◽

Vol 53 ◽

pp. 47-56 ◽

Cited By ~ 1

Author(s):

Binod Dawadi

Keyword(s):

Regression Models ◽

Similar Rate ◽

High Mountain ◽

Climate Data ◽

Southern Slope ◽

Nepal Himalaya ◽

Lower Elevation ◽

Similar Range ◽

Weather Stations ◽

Highly Correlated

To validate the climatic linkages under different topographic conditions, observational climate data at four automated weather stations (AWS) in different elevations, ranging from 130 m asl. to 5050 m asl., on the southern slope of the Nepal Himalayas was examined. the variation of means and distribution of daily, 5-days, 10-days, and monthly average/sum of temperature/ precipitation between the stations in the different elevation was observed. Despite these differences, the temperatures records are consistent in different altitudes, and highly correlated to each other while the precipitation data shows comparatively weaker correlation. The slopes (0.79-1.18) with (R2 >0.64) in the regression models for high Mountain to high Himalaya except in November and 0.56-1.14 (R2 >0.50) for mid-hill and high Mountain except January, December, June indicate the similar rate of fluctuation of temperature between the stations in the respective region. These strong linkages and the similar range of fluctuation of temperature in the different elevation indicate the possibilities of their use of lower elevation temperature data to represent the higher elevation sites for paleoclimatic calibration. However, the associations of precipitation between the stations at the different elevation are not as strong as the temperature due to heterogeneous topographical features and steep altitudinal contrast.

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Analysis of the ENSO Cycle in the NCEP Coupled Forecast Model

Journal of Climate ◽

10.1175/jcli4062.1 ◽

2007 ◽

Vol 20 (7) ◽

pp. 1265-1284 ◽

Cited By ~ 26

Author(s):

Qin Zhang ◽

Arun Kumar ◽

Yan Xue ◽

Wanqiu Wang ◽

Fei-Fei Jin

Keyword(s):

Model Simulation ◽

Southern Oscillation ◽

Coupled Model ◽

Coupled System ◽

Forecast Model ◽

Enso Cycle ◽

Positive Contribution ◽

Test Bed ◽

Model Simulations ◽

Thermocline Feedback

Abstract Simulations from the National Centers for Environmental Prediction (NCEP) coupled model are analyzed to document and understand the behavior of the evolution of the El Niño–Southern Oscillation (ENSO) cycle. The analysis is of importance for two reasons: 1) the coupled model used in this study is also used operationally to provide model-based forecast guidance on a seasonal time scale, and therefore, an understanding of the ENSO mechanism in this particular coupled system could also lead to an understanding of possible biases in SST predictions; and 2) multiple theories for ENSO evolution have been proposed, and coupled model simulations are a useful test bed for understanding the relative importance of different ENSO mechanisms. The analyses of coupled model simulations show that during the ENSO evolution the net surface heat flux acts as a damping mechanism for the mixed-layer temperature anomalies, and positive contribution from the advection terms to the ENSO evolution is dominated by the linear advective processes. The subsurface temperature–SST feedback, referred to as thermocline feedback in some theoretical literature, is found to be the primary positive feedback, whereas the advective feedback by anomalous zonal currents and the thermocline feedback are the primary sources responsible for the ENSO phase transition in the model simulation. The basic mechanisms for the model-simulated ENSO cycle are thus, to a large extent, consistent with those highlighted in the recharge oscillator. The atmospheric anticyclone (cyclone) over the western equatorial northern Pacific accompanied by a warm (cold) phase of the ENSO, as well as the oceanic Rossby waves outside of 15°S–15°N and the equatorial higher-order baroclinic modes, all appear to play minor roles in the model ENSO cycles.

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Storm-Track Activity in IPCC AR4/CMIP3 Model Simulations

Journal of Climate ◽

10.1175/jcli-d-11-00707.1 ◽

2013 ◽

Vol 26 (1) ◽

pp. 246-260 ◽

Cited By ~ 46

Author(s):

Edmund K. M. Chang ◽

Yanjuan Guo ◽

Xiaoming Xia ◽

Minghua Zheng

Keyword(s):

Seasonal Cycle ◽

Storm Track ◽

Coupled Model ◽

Storm Tracks ◽

Intergovernmental Panel ◽

Cmip3 Model ◽

Model Simulations ◽

Storm Track Activity ◽

Highly Correlated ◽

Ipcc Ar4

Abstract The climatological storm-track activity simulated by 17 Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4)/phase 3 of the Coupled Model Intercomparison Project (CMIP3) models is compared to that in the interim ECMWF Re-Analysis (ERA-Interim). Nearly half of the models show significant biases in storm-track amplitude: four models simulate storm tracks that are either significantly (>20%) too strong or too weak in both hemispheres, while four other models have interhemispheric storm-track ratios that are biased by over 10%. Consistent with previous studies, storm-track amplitude is found to be negatively correlated with grid spacing. The interhemispheric ratio of storm-track activity is highly correlated with the interhemispheric ratio of mean available potential energy, and this ratio is biased in some model simulations due to biases in the midlatitude temperature gradients. In terms of geographical pattern, the storm tracks in most CMIP3 models exhibit an equatorward bias in both hemispheres. For the seasonal cycle, most models can capture the equatorward migration and strengthening of the storm tracks during the cool season, but some models exhibit biases in the amplitude of the seasonal cycle. Possible implications of model biases in storm-track climatology have been investigated. For both hemispheres, models with weak storm tracks tend to have larger percentage changes in storm-track amplitudes over the seasonal cycle. Under global warming, for the NH, models with weak storm tracks tend to project larger percentage changes in storm-track amplitude whereas, for the SH, models with large equatorward biases in storm-track latitude tend to project larger poleward shifts. Preliminary results suggest that CMIP5 model projections also share these behaviors.

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A combined observational and modeling approach to study modern dust transport from the Patagonia desert to East Antarctica

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-10-13287-2010 ◽

2010 ◽

Vol 10 (5) ◽

pp. 13287-13335 ◽

Cited By ~ 2

Author(s):

S. Gassó ◽

A. Stein ◽

F. Marino ◽

E. Castellano ◽

R. Udisti ◽

...

Keyword(s):

Boundary Layer ◽

Transport Model ◽

Model Simulation ◽

Dust Cloud ◽

Dust Emission ◽

Ice Cores ◽

Transport Processes ◽

Tierra Del Fuego ◽

Dust Transport ◽

Model Simulations

Abstract. The understanding of present atmospheric transport processes from Southern Hemisphere (SH) landmasses to Antarctica can improve the interpretation of stratigraphic data in Antarctic ice cores. In addition, long range transport can deliver key nutrients normally not available to marine ecosystems in the Southern Ocean and may trigger or enhance primary productivity. However, there is a dearth of observational based studies of dust transport in the SH. This work aims to improve current understanding of dust transport in the SH by showing a characterization of two dust events originating in the Patagonia desert (south end of South America). The approach is based on a combined and complementary use of satellite retrievals (detectors MISR, MODIS, GLAS, POLDER, OMI), transport model simulation (HYSPLIT) and surface observations near the sources and aerosol measurements in Antarctica (Neumayer and Concordia sites). Satellite imagery and visibility observations confirm dust emission in a stretch of dry lakes along the coast of the Tierra del Fuego (TdF) island (~54° S) and from the shores of the Colihue Huapi lake in Central Patagonia (~46° S) in February 2005. Model simulations initialized by these observations reproduce the timing of an observed increase in dust concentration at the Concordia Station and some of the observed increases in atmospheric aerosol absorption (here used as a dust proxy) in the Neumayer station. The TdF sources were the largest contributors of dust at both sites. The transit times from TdF to the Neumayer and Concordia sites are 6–7 and 9–10 days respectively. Lidar observations and model outputs coincide in placing most of the dust cloud in the boundary layer and suggest significant deposition over the ocean immediately downwind. Boundary layer dust was detected as far as 1800 km from the source and $\\sim $800 km north of the South Georgia Island over the central sub-Antarctic Atlantic Ocean. Although the analysis suggests the presence of dust at ~1500 km SW of South Africa five days after, the limited capabilities of existing satellite platforms to differentiate between aerosol types do not permit a definitive conclusion. In addition, the model simulations show dust lifting to the free troposphere as it travels south but it could not be confirmed by the satellite observations due to cloudiness. This work demonstrates that complementary information from existing transport models, satellite and surface data can yield a consistent picture of the dust transport from the Patagonia desert to Antarctica. It also illustrates the limitation of using any of these approaches individually to characterize the transport of dust in a heavily cloudy area.

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