Meteorological Sounding Data Research Articles

北京市观象台2021–2022年气象垂直物理量数据集

Vertical physical parameters are widely used in a lot of fields, such as meteorology and the environment. Due to the complexity of calculations, there is a lack of meteorological vertical physical quantity datasets with long sequences and multiple elements. Based on the meteorological sounding data from Beijing Observatory (station ID 54511) from 2021 to 2022, we used the MICAPS4.0 software to calculate the meteorological vertical physical parameters. The data are recorded twice daily, at 08:00 and 20:00, respectively, covering 40 physical quantities vertical physical parameters, including K index, A index, and maximum uplift index. The dataset has undergone quality control from three aspects: data observation, data transmission, and data storage. It is expected to provide data support for business research work in weather forecasting, atmospheric environment, and other fields.

Changes in the height of the pollution boundary layer and their meteorological effects on the distribution of surface ozone concentrations

Focusing on the key air pollution regions in China by using hourly automatic weather data, ground-based and high-altitude meteorological sounding data, and near-surface O3 monitoring data, here, we try to quantify the relationship between boundary layer meteorological condition and near-surface O3 concentrations. The key meteorological element includes changes in solar zenith angle, cloud height, atmospheric condensation rate, and the associated change in the boundary layer height. We also try to better understand the mechanisms by which meteorological conditions affect near-surface O3 concentrations, and it is found that the exponential increase in near-surface O3 concentrations after sunrise (called the O3 concentration entrainment, EZ) is meaningfully associated with exceeding the threshold of a water vapor condensation rate (fc) that is often closely linked to a significant rise in the pollution boundary layer and that this proves to be diagnostically important for understanding the O3 EZ. Diurnal variations in solar zenith angle and boundary layer height are key meteorological factors influencing the large increase in near-surface O3 concentration entrainment.

DETERMINATION OF THE CHARACTERISTICS OF INVERSION REFLECTING LAYERS IN THE TROPOSPHERE ON CHANGES IN THE SIGNAL INTENSITY ON THE NEAR-EARTH OVER-THE-HORIZON ROUTES IN THE MIDDLE LATITUDES

The methodology for determining changes of altitude, elevation velocity, and reflection coefficient of the elevated inversion layer in the troposphere is examined based on the results of observation of VHF signals on over-the-horizon (OTH) routes. Estimations of the elevation velocity and reflection coefficient of the elevated inversion layers on the results of measuring of the levels of VHF signals in the zone of the near geometric shadow in the middle latitudes and the meteorological sounding data using balloons are obtained.

Impact of planetary boundary layer structure on the formation and evolution of air-pollution episodes in Shenyang, Northeast China

The impact of the planetary boundary layer (PBL) structure on air pollution in Northeast China, where frequently experiences air pollution episodes in autumn and winter, is not well understood due to a lack of observations. In this study, four pollution episodes during autumn and winter of 2016 at Shenyang, a provincial capital city in Northeast China, were examined to investigate the linkage between the PBL structure and air pollution using meteorological sounding data and LiDAR-retrieved profiles of aerosol extinction coefficients. We also conducted a tracer simulation using the Weather Research and Forecasting model with Chemistry (WRF-Chem) to demonstrate the transport and vertical mixing of air pollutants in the PBL. The results indicated that a stable, moist and shallow surface layer (<400 m) formed and remained at night due to strong surface radiative cooling after a steep decline of temperature during the first air-pollution episode (EP1, from 12:00 Local Time (LT) on November 26 to 07:00 LT on November 27). Stable stratification and stagnant winds contributed to the increase of surface pollutant concentrations in EP1. Strong surface potential temperature inversion and enhanced local emissions during evening rush hour resulted in the formation of EP2 (13:00–23:00 LT on December 2). Observations and modelling results revealed that large amount of pollutants were transported by the southerly nocturnal low-level jets from the North China Plain to Shenyang after EP2. These pollutants were trapped in the residue layer at night and then mixed to the surface after sunrise due to convective turbulence, leading to the formation of EP3 (06:00–23:00 LT on December 3). EP4 (03:00–14:00 LT on December 4) occurred in the convergence zone ahead of an approaching trough. Low wind speed (<6 m s−1) and high relative humidity (>80%) in the PBL enhanced the deterioration of air quality near the surface.

Altitude-dependent distribution of ambient gamma dose rates in a mountainous area of Japan caused by the fukushima nuclear accident.

Large amounts of airborne radionuclides were deposited over a wide area in eastern Japan, including mountainous regions, during the devastating Fukushima Dai-ichi nuclear power plant accident. Altitudinal distributions of ambient gamma dose rate in air were measured in a mountainous area at the northern rim of the Kanto Plain, Japan, using a portable instrument carried along the mountain trails. In the Nikko Mountain area, located 120 km north of Tokyo, the altitudinal distribution exhibited a maxima at ∼900-2000 m above sea level (ASL). This area was not affected by precipitation until 2300 Japan Standard Time (JST) on March 15, 2011. By that time, a substantial amount of radionuclides had been transported from the damaged reactor, according to the numerical simulations using transport models. Meteorological sounding data indicated that the corresponding altitudes were within the cloud layer. A visual-range monitor deployed in an unmanned weather station at 1292 m ASL also recorded low visibility on the afternoon of March 15. From these findings, it was deduced that the altitude-dependent radioactive contamination was caused by the cloud/fog deposition process of the radionuclides contained in aerosols acting as cloud condensation nuclei.

Global statistics of multiple tropopauses from the IGRA database

We present statistics for the occurrence of multiple tropopauses for the entire globe, derived from the meteorological sounding data contained in the Integrated Global Radiosonde Archive (IGRA). The IGRA is the most comprehensive and largest radiosonde data set compiled to date, with more than 1500 stations and data starting from 1938. Statistics were derived from (a) the IGRA tropopause reports (reported tropopauses) and (b) tropopauses calculated from the sounding profiles reported in the IGRA (calculated tropopauses). This work constitutes a necessary precursor to conducting better research on the phenomena of multiple tropopauses and promotes understanding of the global structure of these events. Among other things, we calculated global counts and the latitudinal distribution of percentages of tropopauses with respect to the number of soundings, percentages of second and third tropopauses with respect to the first tropopause, and mean values of pressure and temperature of multiple tropopauses.

A possible positive feedback of reduction of precipitation and increase in aerosols over eastern central China

In this study, observed precipitation, MODIS data and meteorological sounding data over eastern central China were analyzed. The result shows that the precipitation in this region is significantly reduced during the last 40 years and this reduction of precipitation is strongly correlated to the high concentrations of aerosols. Meteorological sounding data indicates that the atmospheric stability in the troposphere has been increasing during the last 17 years. It is speculated that the aerosol layer in the lower troposphere affects the radiative processes, which lead to changes in atmospheric stability. The enhancement in the atmospheric stability tends to depress upward motion and precipitation in this region. Because precipitation plays a major role for the sink for aerosol particles through washout process, less precipitation will lead to an increase in aerosol particles. This possible positive feed back cycle (more aerosols → less precipitation → more aerosols) will induce an acceleration process for the reduction of precipitation in eastern central China.

Radiosonde Observations from the Former Soviet “North Pole” Series of Drifting Ice Stations, 1954–90

An historical archive of over 25 000 radiosonde observations from the former Soviet “North Pole” series of drifting ice stations has been compiled and made available to interested researchers. This archive is the only long-term set of meteorological sounding data over the Arctic Ocean. The digital archive is a result of the multiyear, collaborative efforts of a group of United States and Russian scientists and keypunch operators working under the auspices of Working Group VIII, an area of study within the United States–Russian Federation Agreement for Protection of the Environment and Natural Resources. The archive contains soundings from 21 drifting stations over the period 1954–90 and is being distributed by the National Snow and Ice Data Center in Boulder, Colorado.

A Diagnostic Study of the Diurnal Rainfall Variation in the GATE B-Scale Area

Abstract Heat and moisture budgets are used to compute net condensation rates in the GATE B-scale network for four hours of the day: 0000, 0600, 1200 and 1800 GMT. Budgets are presented for all phases combined, for selected periods of enhanced convection and for selected periods of suppressed convection. Computations are based on fitted values of the meteorological sounding data for the center of the B-scale ship array, on surface heat flux and evaporation measurements for seven ships in the array and on Cox and Griffith's (1979) radiation measurements for Phase III. Results are also presented for the diurnal variation of the basic variables. Main findings are as follows: 1) Temperature variations are small, of the order of a few tenths of a degree, with a daytime maximum and nighttime minimum. There is evidence of possible radiation error above 400 mb where the amplitude is largest. 2) The atmosphere appears to be relatively dry during the day, when convection is most active, and relatively moist at nigh...

Sallplane Flights through Funnel Clouds

This paper reports on three intentional flights through small south Florida funnel clouds in a sailplane. Two of the penetrations were through vertical funnels, and one was through a sloping funnel cloud. The latter allowed a more significant immersion time interval within the vortex, and this resulted in much greater effects on the aircraft. With use of the induced variations from normal flight, the instrumentation carried, the physiological observations of the pilot, and the meteorological sounding data, it is possible to deduce some of the characteristics of these funnels.

Average Radio-Ray Refraction in the Lower Atmosphere

Existing corrections for atmospheric refraction in radio-field intensity computations are reviewed with respect to their application to computation of ray bending. A practical scheme is presented for calculating atmospheric refraction of radio-frequency rays numerically from radiosonde data. Ray-bending computations are made for a range of climatological conditions for rays passing entirely through the atmosphere and arriving or departing tangentially at the earth's surface. Some discussion is included regarding the uncertainty in refractive-index computations from meteorological sounding data.