scholarly journals Study of Pluto’s atmosphere based on 2020 stellar occultation light curve results

2021 ◽  
Vol 653 ◽  
pp. L7
Author(s):  
Atila Poro ◽  
Farzaneh Ahangarani Farahani ◽  
Majid Bahraminasr ◽  
Maryam Hadizadeh ◽  
Fatemeh Najafi Kodini ◽  
...  
Keyword(s):  
Light Curve ◽  
Ray Tracing ◽  
Atmospheric Pressure ◽  
Transport Model ◽  
Atmospheric Model ◽  
Atmospheric Parameters ◽  
Sublimation Process ◽  
Stellar Occultation ◽  
Rapid Pressure ◽  
Pressure Evolution

On 6 June 2020, Pluto’s stellar occultation was successfully observed at a ground-based observatory in Iran, and Pluto’s atmospheric parameters were investigated. We used an atmospheric model of Pluto, assuming a spherical and transparent pure N2 atmosphere. Using ray-tracing code, the stellar occultation light curve was satisfactorily fit to this model. We found that Pluto’s atmospheric pressure at the reference radius of 1215 km was 6.72 ± 0.48 μbar in June 2020. Our estimated pressure shows a continuation of the pressure increase trend observed since 1988 and does not confirm the rapid pressure decrease tentatively reported in 2019. The pressure evolution is consistent with a seasonal transport model. We conclude that the N2 sublimation process from Sputnik Planitia is continuing. This study’s result is shown on the diagram of the annual evolution of atmospheric pressure.

scholarly journals Evidence for a rapid decrease of Pluto’s atmospheric pressure revealed by a stellar occultation in 2019

2020 ◽  
Vol 638 ◽  
pp. L5 ◽  
Author(s):  
K. Arimatsu ◽  
G. L. Hashimoto ◽  
M. Kagitani ◽  
T. Sakanoi ◽  
Y. Kasaba ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Atmospheric Pressure ◽  
High Speed ◽  
Theoretical Models ◽  
Atmospheric Model ◽  
Rapid Decrease ◽  
Cmos Camera ◽  
Solar Insolation ◽  
Model Predictions ◽  
Stellar Occultation

We report observations of a stellar occultation by Pluto on 2019 July 17. A single-chord high-speed (time resolution = 2 s) photometry dataset was obtained with a CMOS camera mounted on the Tohoku University 60 cm telescope (Haleakala, Hawaii). The occultation light curve is satisfactorily fitted to an existing atmospheric model of Pluto. We find the lowest pressure value at a reference radius of r = 1215 km among those reported after 2012. These reports indicate a possible rapid (approximately 21−5+4% of the previous value) pressure drop between 2016, which is the latest reported estimate, and 2019. However, this drop is detected at a 2.4σ level only and still requires confirmation from future observations. If real, this trend is opposite from the monotonic increase of Pluto’s atmospheric pressure reported by previous studies. The observed decrease trend is possibly caused by ongoing N2 condensation processes in the Sputnik Planitia glacier associated with an orbitally driven decline of solar insolation, as predicted by previous theoretical models. However, the observed amplitude of the pressure decrease is larger than the model predictions.

scholarly journals Implementation of aerosol–cloud interactions in the regional atmosphere–aerosol model COSMO-MUSCAT(5.0) and evaluation using satellite data

2017 ◽  
Vol 10 (6) ◽  
pp. 2231-2246 ◽  
Author(s):  
Sudhakar Dipu ◽  
Johannes Quaas ◽  
Ralf Wolke ◽  
Jens Stoll ◽  
Andreas Mühlbauer ◽  
...  
Keyword(s):  
Satellite Data ◽  
Transport Model ◽  
Cloud Condensation Nuclei ◽  
Cloud Droplet ◽  
Atmospheric Model ◽  
Horizontal Resolution ◽  
Small Scale ◽  
Aerosol Model ◽  
Aerosol Cloud ◽  
Aerosol Cloud Interactions

Abstract. The regional atmospheric model Consortium for Small-scale Modeling (COSMO) coupled to the Multi-Scale Chemistry Aerosol Transport model (MUSCAT) is extended in this work to represent aerosol–cloud interactions. Previously, only one-way interactions (scavenging of aerosol and in-cloud chemistry) and aerosol–radiation interactions were included in this model. The new version allows for a microphysical aerosol effect on clouds. For this, we use the optional two-moment cloud microphysical scheme in COSMO and the online-computed aerosol information for cloud condensation nuclei concentrations (Cccn), replacing the constant Cccn profile. In the radiation scheme, we have implemented a droplet-size-dependent cloud optical depth, allowing now for aerosol–cloud–radiation interactions. To evaluate the models with satellite data, the Cloud Feedback Model Intercomparison Project Observation Simulator Package (COSP) has been implemented. A case study has been carried out to understand the effects of the modifications, where the modified modeling system is applied over the European domain with a horizontal resolution of 0.25°  ×  0.25°. To reduce the complexity in aerosol–cloud interactions, only warm-phase clouds are considered. We found that the online-coupled aerosol introduces significant changes for some cloud microphysical properties. The cloud effective radius shows an increase of 9.5 %, and the cloud droplet number concentration is reduced by 21.5 %.

scholarly journals Investigating the assimilation of CALIPSO global aerosol vertical observations using a four-dimensional ensemble Kalman filter

2019 ◽  
Vol 19 (21) ◽  
pp. 13445-13467 ◽  
Author(s):  
Yueming Cheng ◽  
Tie Dai ◽  
Daisuke Goto ◽  
Nick A. J. Schutgens ◽  
Guangyu Shi ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Transport Model ◽  
Radiation Transport ◽  
Satellite Observation ◽  
Atmospheric Model ◽  
Orthogonal Polarization ◽  
Spectral Radiation ◽  
Extinction Coefficients ◽  
Model Simulations ◽  
Radiation Transport Model

Abstract. Aerosol vertical information is critical to quantify the influences of aerosol on the climate and environment; however, large uncertainties still persist in model simulations. In this study, the vertical aerosol extinction coefficients from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) onboard the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) are assimilated to optimize the hourly aerosol fields of the Non-hydrostatic ICosahedral Atmospheric Model (NICAM) online coupled with the Spectral Radiation Transport Model for Aerosol Species (SPRINTARS) using a four-dimensional local ensemble transform Kalman filter (4-D LETKF). A parallel assimilation experiment using bias-corrected aerosol optical thicknesses (AOTs) from the Moderate Resolution Imaging Spectroradiometer (MODIS) is conducted to investigate the effects of assimilating the observations (and whether to include vertical information) on the model performances. Additionally, an experiment simultaneously assimilating both CALIOP and MODIS observations is conducted. The assimilation experiments are successfully performed for 1 month, making it possible to evaluate the results in a statistical sense. The hourly analyses are validated via both the CALIOP-observed aerosol vertical extinction coefficients and the AOT observations from MODIS and the AErosol RObotic NETwork (AERONET). Our results reveal that both the CALIOP and MODIS assimilations can improve the model simulations. The CALIOP assimilation is superior to the MODIS assimilation in modifying the incorrect aerosol vertical distributions and reproducing the real magnitudes and variations, and the joint CALIOP and MODIS assimilation can further improve the simulated aerosol vertical distribution. However, the MODIS assimilation can better reproduce the AOT distributions than the CALIOP assimilation, and the inclusion of the CALIOP observations has an insignificant impact on the AOT analysis. This is probably due to the nadir-viewing CALIOP having much sparser coverage than MODIS. The assimilation efficiencies of CALIOP decrease with increasing distances of the overpass time, indicating that more aerosol vertical observation platforms are required to fill the sensor-specific observation gaps and hence improve the aerosol vertical data assimilation.

Occurrence of acute cardiovascular diseases under different atmospheric parameters

2014 ◽  
Vol 155 (27) ◽  
pp. 1078-1082 ◽  
Author(s):  
Nora Boussoussou ◽  
Melinda Boussoussou ◽  
László Entz ◽  
Attila Nemes
Keyword(s):  
Risk Factors ◽  
Cardiovascular Disease ◽  
Seasonal Variation ◽  
Cardiovascular Diseases ◽  
Vascular Surgery ◽  
Atmospheric Pressure ◽  
Meteorological Parameters ◽  
Atmospheric Parameters ◽  
Prevention Strategies ◽  
Maximum Daily Temperature

Introduction: Research on the effects of meteorological parameters on cardiovascular diseases may allow the development of novel prevention strategies. Aim: The aim of the authors was to examine the correlation between meteorological parameters and the occurrence of acute cardiovascular diseases. Method: A retrospective analysis was performed in 343 patients diagnosed with acute cardiovascular disease and treated at the Department of Vascular Surgery, Semmelweis University in 2010. Results: Acute cardiovascular diseases showed a seasonal variation with the highest occurrence in winter months (p = 0.0001). The daily increase of the events (n≥3) were associated with front movements days (in 62.5% of cases). A significant correlation was found between the intraday temperature difference (p<0.0001), the intraday atmospheric pressure difference (p = 0.0034), the lowest maximum daily temperature (p<0.0001) and the occurrence of acute cardiovascular diseases. During the days with front movements 64% of the patients were older than 66 years of age. Among risk factors, hypertension showed front sensitivity. Conclusions: Meteorological parameters are minor risk factors in the occurrence of acute cardiovascular diseases. Orv. Hetil., 2014, 155(27), 1078–1082.

scholarly journals Ocean–Atmosphere Feedback during Extreme Rainfall Events in Eastern Northeast Brazil

2018 ◽  
Vol 57 (5) ◽  
pp. 1211-1229 ◽  
Author(s):  
Thiago Luiz do Vale Silva ◽  
Doris Veleda ◽  
Moacyr Araujo ◽  
Pedro Tyaquiçã
Keyword(s):  
Transport Model ◽  
Inversion Layer ◽  
Lower Troposphere ◽  
Extreme Rainfall ◽  
Atmospheric Model ◽  
Heat Fluxes ◽  
Northeast Brazil ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Ocean Atmosphere

AbstractThe coupled ocean–atmosphere–wave–sediment transport model and the Weather Research and Forecasting (WRF) atmospheric model were used to simulate extreme rainfall events from 10 to 25 June 2010 in eastern Northeast Brazil (ENEB). The simulations aimed at investigating the improvements from using a coupled ocean–atmospheric model of meteorological systems as the ocean–atmosphere interactions intensified during the period when flood events occurred in ENEB. In June 2010, the sea surface temperature (SST) was warmer than 28.5°C in the western tropical South Atlantic Ocean with anomalies above 1°C, which are characteristics of a warm pool. The sensible and latent heat fluxes acted to moisten the lower troposphere and affected the height of the trade winds inversion layer (TWIL). The meteorological system that occurred at the low–midlevels during the period favored the weakening and even the breakdown of the TWIL. These atmospheric disturbances were associated with convergence, cyclonic vorticity, and upward water vapor motion to the midtroposphere levels. When the disturbances reached the coast of ENEB, they favored convection and intense rainfall over the region. Both coupled and uncoupled modeling experiments were performed with the same physical parameterizations and validated with in situ atmospheric and oceanic measurements. The results highlight that the predictions of extreme rainfall events were greatly improved with the coupled model.

scholarly journals Meteorological effects in the lower ionosphere as based on VLF/LF signal observations

2014 ◽  
Vol 2 (4) ◽  
pp. 2789-2812 ◽  
Author(s):  
A. Rozhnoi ◽  
M. Solovieva ◽  
B. Levin ◽  
M. Hayakawa ◽  
V. Fedun
Keyword(s):  
Gravity Waves ◽  
Atmospheric Pressure ◽  
Low Frequency ◽  
Lower Ionosphere ◽  
Signal Amplitude ◽  
Internal Gravity Waves ◽  
Atmospheric Parameters ◽  
Low Latitudes ◽  
Far Eastern ◽  
Meteorological Effects

Abstract. Very low and low frequency (VLF/LF) data recorded in the Far Eastern stations Petropavlovsk-Kamchatsky (158.92° E, 53.15° N), Yuzhno-Sakhalinsk (142.75° E, 46.95° N) and Yuzhno-Kurilsk (145.861° E, 44.03° N) are investigated to study the meteorological effects in the lower ionosphere. The results demonstrate the sensitivity of the VLF/LF signals to the variations of atmospheric pressure, humidity, wind velocity and temperature, and the VLF/LF record at the station of Yuzhno-Kurilsk is found to be most sensitive to those variations of atmospheric parameters. The region under consideration is characterized by high winter cyclonic activity in midlatitudes and strong summer and autumn typhoon activity in low latitudes. VLF/LF signal variations during 8 tropical cyclones (TCs) with different intensity are considered. Negative nighttime anomalies in the signal amplitude that are most probably caused by TC activity are found for 6 events. Those anomalies are observed during 1–2 days when TCs move inside the sensitivity zones of the subionospheric paths. Perturbations of the VLF signal observed during 2 TCs can be caused by both the TC influence and seismic activity, but no correlation between TC intensity and magnitude of the signal anomalies is found. Spectral analysis of the typhoon-induced disturbed signals revealed the fluctuations with time periods in the range of 7–16 and 15–55 min that corresponds to the range of internal gravity waves periods.

scholarly journals ATMOSPHERICALLY COMPENSATED SHAPE FROM SHADING ON THE MARTIAN SURFACE: TOWARDS THE PERFECT DIGITAL TERRAIN MODEL OF MARS

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 1405-1411
Author(s):  
M. Hess ◽  
K. Wohlfarth ◽  
A. Grumpe ◽  
C. Wöhler ◽  
O. Ruesch ◽  
...  
Keyword(s):  
Digital Terrain Model ◽  
Ground Truth ◽  
Atmospheric Model ◽  
Shape From Shading ◽  
Initial Surface ◽  
Atmospheric Parameters ◽  
Martian Surface ◽  
Atmospheric Compensation ◽  
Digital Terrain ◽  
Diffuse Illumination

<p><strong>Abstract.</strong> We have expanded our existing Shape and Albedo from Shading framework which has primarily been used to generate Digital Terrain Models (DTMs) of the Lunar Surface. The extension consists of an atmospheric model such that the approach can be applied to Mars which is covered by a thin atmosphere. The atmospheric model includes attenuation by the atmosphere, diffuse illumination of the surface and scattering from the atmosphere into the direction of the sensor with physically motivated parameters. To estimate the newly introduced atmospheric parameters without additional CRISM measurements, the radiance image and an initializing surface are used. The initial surface is derived from stereo images and serves two purposes. On the one hand, it is the height constraint of the SfS algorithm and on the other hand, it is used for estimating the atmospheric parameters. Relying on this estimation, the aforementioned Shape and Albedo from Shading method is carried out. The results show a considerable improvement compared to DTMs derived with stereo algorithms. The omnipresent stereo artifacts such as pixel locking and mismatches are smoothed out and small details are reconstructed convincingly. The procedure is then compared to the reconstruction without atmospheric compensation. Images in which shadows are present benefit from this method because shadows can now be described by the diffuse illumination of the surface. The reconstruction results indicate the viability of the approach since it can produce convincing DTMs compared to HiRISE ground truth.</p>

P6141Associations between atmospheric parameters and haemostatic factors: a case control study

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
M Boussoussou ◽  
N Boussoussou ◽  
M Rakovics ◽  
L Entz ◽  
A Nemes
Keyword(s):  
Climate Change ◽  
Temperature Variation ◽  
Global Climate Change ◽  
Atmospheric Pressure ◽  
Blood Donors ◽  
Global Climate ◽  
Daily Temperature ◽  
Atmospheric Parameters ◽  
Linear Effect ◽  
Haemostatic Factors

Abstract Background One of the biggest health challenges in the 21st century is global climate change. The health effect of climate change is partly mediated through atmospheric parameters. There is a growing concern that atmospheric parameters might increase cardiovascular (CV) morbidity. Increased levels of haemostatic factors are predictors of CV events. The associations between CV diseases and atmospheric parameters have been widely reported, however there are few studies of atmospheric parameters' effects on markers of haemostasis. Purpose We examined the possible association between atmospheric parameters and several haemostatic markers. Methods The study consisted of 3800 hospitalized patients with acute CV diseases (ACVDs) and 260 healthy blood donors. We examined the relationship of haemoglobin (Hgb), white blood cells (WBC), thrombocytes (THR) and local atmospheric parameter conditions (temperature, atmospheric pressure, humidity, wind speed, atmospheric front) on a day-to-day basis in a 5-year period (2009–2013) using a General Additive Model with cubic splines of covariates, regularized by a ridge penalty, and employing generalized cross validation. Atmospheric parameters were allowed to have a lagged effect by up to 21 days. Results Among blood donors, the average of daily temperature lagged by 8–14 days had a significant effect on Hgb, exhibiting a U-shaped relationship, where higher Hgb values were associated with extremities of the observed temperature interval. For ACVD patients, all examined blood test variables has a significant association with at least some of the atmospheric parameters. Hgb was shown to have a negative linear relationship with mean daily humidity, and the average of daily temperature lagged by 15–21 days, while the average of daily temperature variation lagged by 2–7 days had highly non-linear effect. The relative strength of the association with Hgb was largest for daily temperature variation. WBC values had a slightly non-linear positive relationship with atmospheric pressure lagged by 1 day, with WBC being significantly increased above 1030 hPa. THR values decreased linearly with an increase in mean daily temperature averaged for days lagged 15–21. Atmospheric pressure lagged by 1 day also had a significant effect on THR, with a positive linear effect under 1010 and over 1020 hPa but no effect between. The relative effect of atmospheric pressure on THR was twice as large compared to temperature. Conclusions Our study showed that exposure to certain atmospheric parameters is associated with significant changes in haemostatic marker levels. In the context of global climate change, the importance of focusing on atmospheric parameters as minor CV risk factor is substantially growing. A better understanding of the fluctuation of the examined markers, in light of atmospheric parameters, appears to be of particular importance for future studies and could help establish new CV prevention strategies.

scholarly journals Ice nucleating particles over the Eastern Mediterranean measured by unmanned aircraft systems

2016 ◽  
Author(s):  
Jann Schrod ◽  
Daniel Weber ◽  
Jaqueline Drücke ◽  
Christos Keleshis ◽  
Micheal Pikridas ◽  
...  
Keyword(s):  
Transport Model ◽  
Eastern Mediterranean ◽  
Lower Troposphere ◽  
Ground Level ◽  
Atmospheric Model ◽  
Unmanned Aircraft ◽  
Unmanned Aircraft Systems ◽  
Saharan Dust ◽  
Cloud Formation ◽  
Aircraft Systems

Abstract. During an intensive field campaign on aerosol, clouds and ice nucleation in the Eastern Mediterranean in April 2016, we have measured the abundance of ice nucleating particles (INP) in the lower troposphere from unmanned aircraft systems (UAS). Aerosol samples were collected by miniaturized electrostatic precipitators onboard the UAS at altitudes up to 2.5 km. The number of INP in these samples, which are active in the deposition and condensation modes at temperatures from −20 to −30 °C, were analyzed immediately after collection on site using the ice nucleus counter FRIDGE. During the one month campaign we encountered a series of Saharan dust plumes that traveled at several kilometers altitude. Here we present INP data from 42 individual flights, together with aerosol number concentrations, observations of lidar backscattering, dust concentrations derived by the dust transport model DREAM (Dust Regional Atmospheric Model), and results from scanning electron microscopy. The effect of the dust plumes is reflected by the coincidence of INP with the particulate mass (PM), the lidar signal and with the predicted dust mass of the model. This suggests that mineral dust or a constituent related to dust was a major contributor to the ice nucleating properties of the aerosol. Peak concentrations of above 100 INP std. l−1 were measured at −30 °C. The INP concentration in elevated plumes was on average a factor of 10 higher than at ground level. Since desert dust is transported for long distances over wide areas of the globe predominantly at several km altitude we conclude that INP measurements at ground level may be of limited significance for the situation at the level of cloud formation.

Deriving Optimum Visibility Range and Aerosol Loading from Urban Atmospheric Model in Malaysia

2012 ◽  
Vol 518-523 ◽  
pp. 5784-5787
Author(s):  
Wan Noni Afida Ab Manan ◽  
Arnis Asmat ◽  
Noordin Ahmad
Keyword(s):  
Water Vapor ◽  
Radiative Transfer ◽  
Optical Thickness ◽  
Atmospheric Model ◽  
Surface Reflectance ◽  
Atmospheric Parameters ◽  
Kuala Lumpur ◽  
Optimum Range ◽  
Aerosol Loading ◽  
Visibility Range

Visibility, aerosol optical thickness and water vapor are important atmospheric parameters that vary in space and time. Using radiative transfer algorithm to derive surface reflectance from imaging these values would be critical to be assigned. This study will investigate the optimum range of visibility and aerosol loading in Malaysia deriving from atmospheric model. Urban atmospheric model was performed into two major cities in Malaysia to represent for ideal tropical climate. The study found that the farthest visibility range at 50km,the aerosol loading was low and the shortest range at 10 km was contain high aerosol loading. Relatively, aerosol loading estimation is higher at close-shore city (Penang) than inland city (Kuala Lumpur).

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