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Wen 丨 has seen the big dragon in the world
Editor丨 has seen the big dragon in the world
preface
Weather forecasting in the Southern Ocean and Antarctica is first and foremost a challenge, the observational data that needs to be absorbed in numerical weather prediction models is small, logically challenging, it is important to assess the possible benefits of additional observations, and atmospheric sounding using drones has great potential to complement conventional radiosonde observations.
UAV and radiosonde observations in the snow-covered Weddell Sea in winter, assessing the impact of their assimilation in polar versions of weather research and forecasting models, revealing small to moderate impacts of radiosonde and UAV data assimilation, absorbing detection data from radio satellites and drones, and improving the analysis of temperature, wind speed and humidity at observation sites for the most part.
Temperature and humidity sensitive microwave radiation
The impact on the polar experiment results is often seen everywhere at a distance of at least kilometers from the observation point, successfully capturing the main characteristics of the evolution of near-surface variables, the impact of data assimilation is different, due to the limited vertical range of UAV observation, the impact of assimilation is limited to the lowest layer, while the assimilation of radiosonde data is more conducive to simulating sea level pressure and near-surface wind speed.
Observations from the Southern Ocean and Antarctica are critical for climate research and operational weather forecasting, and the number of in-situ observations made in these regions is very limited, and from the point of view of numerical weather prediction, more in situ observations of the distribution of atmospheric pressure, temperature, moisture and wind are particularly needed.
These are important for model initialization, and near-surface observations from weather stations and buoys are not enough, but also profiling observations are required to evaluate the results of the model, and a large amount of profile observations are collected through satellite remote sensing, which are often absorbed into the model's temperature- and humidity-sensitive microwave radiation has been an important part of the global observing system.
The assimilation of these radiations through the parameterization of surface snow and sea ice emissivity has yielded important information about air temperature and humidity profiles, especially in areas with few in-situ observations, where the assimilation of microwave and infrared data over Antarctica affects the spatial pattern of various variables.
Radiometric assimilation and retrieval measurements with atmospheric infrared sounders have a significant impact on analysis and short-term forecasting, and this improvement is mainly reflected in the prediction of humidity, temperature, wind and rainfall.
The spatial gap between Antarctica and the Southern Ocean is even greater, with radiosonde bathymetric stations mostly located along coastlines requiring more radiosondes or other in-situ observations of temperature, humidity and wind distribution inside the Southern Ocean and Antarctic ice sheets.
Impact of radiosonde data
The impact of polar radiosonde data on models is mainly studied in the Arctic, and radiosonde observations based on Arctic campaigns reduce analytical errors in the upper troposphere, thereby improving forecasting skills and reducing the uncertainty of predicting extreme weather in remote areas.
Several radiosonde observations also have a considerable impact on the prediction of Arctic cyclones, investigating the impact of radiosonde data from the ice-free Arctic Ocean, focusing on the density of observation networks, frequent radiosonde observations in the Arctic Ocean, improving the accuracy of overall reanalysis of experiments locally and throughout the northern northern hemisphere impact even for weeks.
The impact of radiosonde data on short-term forecasting may disappear, the impact of radiosonde assimilation depends on the case studied and the potential experimental setup, in addition to improving weather forecasting, absorbing sounding data can also help improve sea ice forecasting, and assimilation of radiosonde data based on Arctic campaigns using coupled ice ocean models can help predict strong wind events and predict wind-driven sea ice advection.
Assimilation of radiosonde data provides a better prediction of sea ice distribution, especially in the presence of strong cyclones near the detection site, and in situ observations of high altitude temperature, wind and specific humidity can also be obtained from aircraft and pilot balloons and wind profilers, absorbing the benefits of radiosonde and wind analyzer data at high latitudes where in-situ observations are rare.
To study the temperature and humidity of satellites and ground-based microwave radiometers, atmospheric sounding can also be applied by drones, as a UAV small unmanned weather observer has demonstrated its applicability in a wide range of field research applications, how to use the temperature, humidity and wind profile of the lower troposphere obtained to improve numerical weather simulations by applying weather research and forecasting models.
Atmospheric profiles retrieved near a high mountain in Iceland were assimilated in advanced research editions to capture complex weather conditions when forced to observe wind and temperature distributions, and the effects of data assimilation occurred not only downwind of observation points, but also in the coastal areas of Antarctica, with a unique observation mission in the Southern Ocean complementing daily radiosondes.
Vertical variability of temperature and humidity
Polaris cruises in the Ice Weddell Sea in winter, conducting experiments on the effects of assimilation on RV polar radiosondes and drone observations model analysis and simulation, finding out the benefits of radiosondes and UAV models observed in the Southern Ocean in winter, based on a commercial construction kit called Multiway, equipped with Lindenberg and weather sensors provided by Mueller.
Measuring the contours of meteorological variables during the cruise of the RV, the observation of temperature, humidity and wind direction, the cruise of the RV is divided into different ice stations, the temperature and humidity sensor has a thermal inertia descent rate slightly slower than the ascent rate, the data from the descent profile is more accurate, and the numerical method can be calculated to correct the sensor lag.
In the lower troposphere, especially below the altitude meter, temperature and humidity profiles tend to have considerable vertical variability, such profiles are particularly challenging for correcting sensor hysteresis, we chose not to apply this correction to the profile, defining the observation time of the profile as the time corresponding to the descent middle, and manually controlled trajectories are not as stable as at higher levels.
Excluding wind observations For pressure, humidity and temperature, the temperature distribution of rising and falling at a minimum of tens of meters, each profile averaging more than meters at an altitude of the polar tail Polar Tail radiosonde uses radiosonde equipment on the right-handed rotor to make daily contour measurements of pressure, temperature, relative humidity, and wind vector.
Because solar and infrared radiation can significantly affect the accuracy of radiosonde temperatures at high altitudes, balloons on Polaris are launched from the helicopter deck at altitude, ignoring the lowest individual record of radiosonde observations and avoiding the ship's flow interference and heating effects.
The data assimilation experiment uses the contour data of atmospheric pressure, wind speed, wind direction, air temperature, humidity and other contour data of the radiosonde observations, and the vertical resolution of the radiosonde observation results is about meters, and the vertical average value is not taken for a typical radiosonde profile, and the radiosonde and observation results assimilated in polar experiments.
Weather and climate studies in the Arctic and Antarctic
In addition to the cross-sectional observations of the radiometer, the observations of the automatic weather station on the north pole of the RV are used to verify the results of the simulation, obtaining atmospheric pressure, air temperature, air humidity and wind records, the measurement of atmospheric pressure has been reduced to sea level, and the real wind is taken into account and gyro heading data, using a radiation shield installed in an unventilated radiation shield.
Interpolate values at the model level to the observation level, using meteorological observations from the Newmel III station in Dronningmod Land, Antarctica, to better represent the physical processes in the polar region, which is mainly used by the United States for operational weather forecasting in Antarctica. The Antarctic mesoscale prediction system operates throughout the continent and surrounding oceans.
Initial conditions and boundary conditions were extracted from operational analysis, and a four-dimensional data assimilation system was used to absorb radiosondes and data from the polar regions, each grid point had grid points, horizontal resolution was designed to cover the detection point and downstream area, and the data assimilation strategy was based on the specific period of observation.
In order to assess the potential benefits of assimilating radiosonde and meteorological sounding observational profile data, observational pushes were used to locally force simulation pairs and radiosonde observations using observational data to push model values to observations and continually incorporate observations into model simulations to prevent model predictions from moving away from observations.
The assimilation experiment uses variables such as pressure, altitude, humidity, wind, temperature, etc., and the assimilation time window of each profile is hours, which can evaluate the impact of these observations on the simulation, and the impact on the local analysis is to demonstrate how the assimilation process of the detection data affects the model analysis.
The profiles were extracted from the first analysis of and did not compare the analyses, since the radiosonde observation time i.e. the simulated time was in the morning, they did not overlap with the observed time, and this temperature, wind and relative humidity analysis included the assimilation of radiosonde observations and the observations more in line with the observed contours than the analysis.
Impact of radiosonde and analog data
The positive effects of radiosonde observations, i.e. assimilation profiles closer to observations, in addition to different observation altitudes, differences in the influence of radiosonde data and data may also be affected by the time difference between radiosonde data and observation data, and wind speed profiles are also affected by the absorption of mean sea level pressure and air temperature profile data.
Compared with the temperature profile, the wind and humidity profiles based on radiosonde and data assimilation are not as detailed as the observation profiles and temperature profiles, and the profiles of experiments that capture the main features of observations at high altitudes tend to be close to the profiles of experiments, and the assimilation of radiosondes and analog data has a significant positive effect on local analysis.
Effects of Parametric Model Experiments on the Polastern Orbit By comparing the time series of several variables on the RV Polaris cruise orbit, studying the effects of data assimilation on the Sky Model experiment, the difference between the simulation and the observation of the time series, relative humidity and specific humidity usually produce better results than and produce better results shortly after radiosonde detection, and are almost identical except for the first half of most observations being assimilated.
The small positive effects of data assimilation relative to the improvement, the assimilation of observations has a slight positive effect on the results, the positive effects of unreasonable radio noise disappear shortly after assimilation, and the relationship between profile observations and simulated near-surface wind speeds can still be found when simulated observations are available for assimilation.
Slightly superior in the simulation of relative humidity and specific humidity, especially when the observations are assimilated, the assimilated bathymetric data cannot have much impact when evaluating the observations made on ships located upstream of the observation site, and the effect of assimilation on the simulation of the Antarctic Observatory is interesting in addition to the model results along the orbit of the North Star.
Wind speed and wind direction of Neumeyer station, simulation they seem to have captured the main changes in air pressure determination and wind speed, the largest difference in the Xindan simulation and observed temperature It is up to the magnitude, in the simulation results found a large error in the case of the change of wind direction, the result of assimilation is almost the same as in all variables as in the simulation in all cases.
epilogue
Knowing that drone activities still require human labor and that radiation robots can also be launched automatically, it is foreseeable that drone operations will also be automated in the future, and since all Antarctic observations are expensive and logically challenging but the technology is constantly evolving, more work needs to be done to fully assess the costs and benefits that various additional observations may bring to Antarctica.
The operation of drones will also be automated in the future, and since all Antarctic observations are expensive and logically challenging, the evolving technology requires more work to fully assess the costs and benefits that various additional observations may bring to Antarctica.
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