The Acoustic Nature of “Storm Nose”, “Supercell” Vortices and Tornadoes

The process of cumulonimbus cloud Cb calvus formation in the middle latitudes of real atmosphere is analyzed in this work. Its transformation from initial lifecycle stage to “maturity” undergoes due to the formation of the waveguide called “aerial acoustic channel” in the troposphere near the level of temperature minimum that is close to 2 km altitude. This “aerial acoustic channel” can be considered as analog of “deep sound channel” that corresponds to the minimal sound speed level. Tropospheric “channel” related to the thermal inversion zone is almost unlimited horizontally. Synchronous generation of two compression waves (ascending one above Cb and descending one inside Cb) is caused by Cb calvus dome ascension. The first one can provoke the aerodynamic draft previously unexplained. The second one results in the growth of its “storm nose” and in the axial and peripheral descending mechanisms in Cb. The penetration of Cb into stratosphere results in the destruction of dynamic balance around Cb top and hence in its unloading in the descending decompression wave. Here the air cools down to the “dew point” in the place of conjugation with parental cloud – due to Snellius law it results in the formation of aerosol “vortex” as condensation front; this “vortex” has calculated value of its generatrix against vertical. Due to D. Snow’s criterion, this vortex forms either “supercell” vortex or tornado vortex.

Ice in caves and its effect on thermal inversion and permafrost in the case of the Velika ledena jama v Paradani, Smrekova draga and neighbouring dolines

In the Velika ledena jama v Paradani, in the karstic blowholes on the slopes of Smrekova draga and in the nearby dolines I measured and interpreted air temperatures and the effect of the summer outflow of cold air from them into the surrounding area. In winter, cold air enters the cave, radically cooling the entrance part of the cave, where for this reason there is permanent cave ice. The summertime circulation is reversed: emerging from the inner part of cave, which has an average temperature of around 4° C, is air which only when it transits through the sub-cooled entrance part is then cooled to around 1° C. This air comes to the surface and in the hollow at the cave entrance maintains a distinct thermal inversion during the warm part of the year. There is a similar air circulation and similar development of annual temperatures observed at the vents, where cave air emerges through rubble spread over cave entrances on slopes or at the bottom of dolines. The stable summer air temperatures of around 1° C in the vents where I conducted measurements indicate that underneath them there is also permafrost or sub-cooled rock and permanent ice. This is created and preserved, just like in the caves, due to the advection of cold air in winter. In Trnovski gozd, such karstic permafrost is found at an altitude of 1,100 m above sea level. The outflow of cold air from the vents in the summer, just like inside the cave, causes a distinct thermal inversion in dolines on the surface.

The Labor Productivity Consequences of Exposure to Particulate Matters: Evidence from a Chinese National Panel Survey

A growing body of literature has documented the negative impacts of air pollution on labor productivity, especially the effects of fine particulate matter. In this paper, we build on this literature by dissecting two channels of how particulate matter affects labor productivity: decreasing labor supply through damaging the physical functioning of the human body, and decreasing the marginal productivity of labor through damaging the cognitive functioning of the human brain. Using the household panel survey from the China Health and Nutrition Survey (CHNS) spanning 2000 to 2015 and combining that information with remotely sensed data on exposure to particulate matter (PM2.5), namely, the most harmful air pollution, we find a significantly negative effect of PM2.5 (instrumented by thermal inversion) on labor productivity. We also find that workers who are male, without a college degree, and are employed in outdoor occupations are mainly affected by PM2.5 through decreasing working hours, whereas college-educated workers employed in indoor occupations are mainly affected by PM2.5 through decreasing unit wages. We provide suggestive evidence that health impacts are behind our measured labor-productivity losses as we find significantly lower metrics in physical activity and increasing disease prevalence under higher exposure to PM2.5.

Comparison of the influence of two types of cold surge on haze dispersion in eastern China

Cold surge (CS) is considered a favorable weather process to improve air quality and is widely recognized. However, there is no detailed study on the differences in the dispersion ability of different types of CSs in relation to haze days in eastern China (HDEC). This paper uses the hierarchical clustering algorithm to classify the cool-season (November to February of the following year) CSs across eastern China into blocking CSs and wave-train CSs and compares their influences on the number of HDEC from 1980 to 2017. Results show that the wave-train CSs can significantly improve the visibility in eastern China and generally improve air quality for about 2 d longer than the blocking CSs, which indicates that the blocking CSs have a weaker ability to dissipate HDEC compared with the wave-train CSs. The CSs affect the HDEC by changing meteorological elements like thermal inversion potential, horizontal surface wind, sea level pressure (SLP), and surface air temperature (SAT). A period of 4 d after the outbreak of CSs, the variations of thermal inversion potential and horizontal surface wind of two types of CSs tend to be consistent. However, the negative SAT anomalies and the positive SLP anomalies caused by the blocking CSs lasted shorter than those caused by the wave-train CSs, forming favorable conditions for the rapid growth of HDEC. Furthermore, results show that in recent years, especially after the 1990s, the frequency of wave-train CSs has decreased significantly, while the frequency of blocking CSs has slightly increased, indicating that the overall ability of CSs to dissipate HDEC has weakened in general. This work may provide reference for the future formulation of haze control policies in East Asia.

Hydrographic Processes in a Tropical Coastal Lagoon on Western Bay of Bengal

In this article, hydrographic processes of a tropical coastal lagoon is studied that control inherent biological mechanisms of the lagoon environment. Realizing the interest of environmentalists over physio-chemical studies of a wetland tropical wetland system on the western boundary of the Bay of Bengal, a high-resolution intensive vertical hydrographic field campaign was carried during monsoon to uncover peculiarity in vertical hydrographic processes that was long-awaited to address many environmental issues. Vertical hydrographic profiles on spatio-temporal scale were made at nine stations in a zonal direction of the Chilika lagoon system. Results of vertical variability of salinity showed the presence of higher saline water over less saline water in the central-western region. The higher and lower water temperature in the western and eastern parts of the lagoon, respectively, indicated temperature dipole between the two regions. The encapsulation of water mass having higher temperature by the water of lower temperature at the central region resulted evolution of thermal inversion. The highest dissolved oxygen concentration was observed in the sub-surface layers of the western part of the lagoon. However, a layer of near-hypoxia occurred below 1.5 m depth in the central region. This study proposes comprehensive inter-seasonal studies to address the vertical variability of biogeochemical parameters and the fate of organic flux.

The Morbidity Costs of Air Pollution through the Lens of Health Spending in China

This study offers one of the first causal evidence on the morbidity costs of fine particulates (PM2.5) for all age cohorts in a developing country, using individual-level healthcare spending data from the basic medical insurance program in Wuhan, China. Our instrumental variable (IV) approach uses thermal inversion to address potential endogeneity in PM2.5 concentrations and shows that PM2.5 imposes a significant impact on medical expenditures. The IV estimate suggests that a 10 μg/m3 reduction in monthly average PM2.5 leads to a 2.79% decrease in the value of health spending and a 0.70% decline in the number of transactions in pharmacies and health facilities. The effect is more salient for males, children, and older adults. Moreover, our estimates provide a lower bound of people's willingness-to-pay, which amounts to CNY 51.85 (or USD 8.38) per capita per year for a 10 μg/m3 reduction in PM2.5.

Neyo: A katabatic dry wind

The objective of this study is to explain how the Neyo wind stream develops and how it can damage crops and endanger people’s lives in the Darfur Region of Sudan. Due to lack of official meteorological observations, the data was retrieved from NOAA Air Resources Laboratory (ARL) used by the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT). Three scenarios for katabatic flow were formulated. Forces acting on air parcels were calculated for different slope angles. HYSPLIT vertical soundings revealed a reservoir of dry air over the area. Air parcels moving down slope allow dry air to flow across the thermal inversion layer. Due to the moisture deficit between the down flowing air and the humid grass surface, the leaves get dehydrated.

Optical and Infrared Phase Curves of the Lava Planet K2-141 b

<p>K2-141 b is a transiting, small (1.5 RE) Ultra-Short-Period (USP) planet orbiting its star every 6.7 hours discovered by the Kepler space telescope. The planet’s high surface temperature of more than 2000 K makes it an excellent target for atmospheric studies by the observation of its thermal emission. We present 65 hours of continuous photometric observations of K2-141 b collected with Spitzer’s IRAC Channel 2 at 4.5 microns spanning 10 full phases of the orbit. Our best fit model of the Spitzer data shows no significant offset of the thermal hotspot and is inconsistent with the observed offset of the well-studied USP planet 55 Cnc e at a 3.7 sigma level. We measure an eclipse depth of 142 +/- 40 ppm and an amplitude variation of 120 +/- 40 ppm in the infrared. The joint analysis of the observations collected in the two photometric bands favors a non-zero geometric albedo with Ag = 0.26 +/- 0.07 and a tentative temperature gradient. With a dayside temperature of 2141 -361 +352 K and a night-side temperature of 1077 -623 +473 K we also find no evidence of heat redistribution on the planet. We compare the observations to a 1D rock vapor model and a 1D circulation toy model and argue that the data are best explained by a thin rock vapor atmosphere with a thermal inversion.</p>

Comparison of influence between two types of cold surge on haze dispersion in Eastern China

Cold surge (CS) is considered as a favorable weather process to improve air quality and is widely recognized. However, there is no detailed study on the differences in the dispersion ability of different types of CSs to haze days in eastern China (HDEC). This paper uses the hierarchical clustering algorithm to classify the cool season (November to February of the following year) CSs across eastern China into blocking and wave-train CSs and compares their influences on the number of HDEC from 1980 to 2017. Results show that the wave-train CS can significantly improve the visibility in eastern China and generally make the high air quality last for about 2 days longer than the blocking CS, which indicates that the blocking CS has a weaker ability to dissipate HDEC compared with the wave-train CS. The CSs affect the HDEC by changing these meteorological elements like thermal inversion potential, horizontal surface wind, sea level pressure (SLP), and surface air temperature (SAT). 4 days after the CSs outbreak, the variations of thermal inversion potential and horizontal surface wind of two types of CSs tend to be consistent. However, the negative SAT anomalies, and the positive SLP anomalies caused by the blocking CSs lasted shorter than those caused by the wave-train CSs, which forms favorable conditions for the rapid growth of HDEC. Furthermore, results show that in recent years, especially after the 1990s, the frequency of wave-train CSs has decreased significantly, while the frequency of blocking CSs has slightly increased, indicating that the overall ability of CSs to dissipate HDEC has weakened in general.