Development for wind friction velocity retrieval algorithm based on the SFMR and NOAA dropwindsondes measurements in hurricane conditions

2021 ◽  
Author(s):  
Evgeny Poplavsky ◽  
Nikita Rusakov ◽  
Olga Ermakova ◽  
Daniil Sergeev ◽  
Yuliya Troitskaya ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Atmospheric Boundary Layer ◽  
Friction Velocity ◽  
Microwave Radiometer ◽  
Field Measurements ◽  
Retrieval Algorithm ◽  
Self Similarity ◽  
Defect Profile ◽  
Stepped Frequency

<p>The work is concerned with the development of a method for the retrieval of tropical cyclones boundary atmospheric layer parameters, namely the wind friction velocity and wind speed at meteorological height. For the analysis, we used the results of field measurements of wind speed profiles from dropwindsondes launched from National Oceanic and Atmospheric Administration (NOAA) aircraft and collocated data from the Stepped-Frequency Microwave Radiometer (SFMR) located onboard of the same aircraft.</p><p>The results of radiometric measurements were used to obtain the emissivity values, which were compared with the field data obtained from the falling dropwindsondes. Using the algorithm taking into account the self-similarity of the velocity defect profile (Ermakova et al., 2019), the parameters of the atmospheric boundary layer were determined from the data measured by dropwindsondes. This algorithm gives an opportunity to obtain the wind speed value at meteorological height and wind friction velocity from the averaged data in the wake part of the profiles of the marine atmospheric boundary layer.</p><p>A comparison of the wind speed U10 dependencies, retrieved from the SFMR data and measurements from dropwindsondes, with the similar dependencies obtained in (Uhlhorn et al., 2007), was made, and their satisfactory agreement was demonstrated. This work was supported by the RFBR projects No. 19-05-00249, 19-05-00366.</p>

scholarly journals Revisiting the Definition of the Drag Coefficient in the Marine Atmospheric Boundary Layer

2010 ◽  
Vol 40 (10) ◽  
pp. 2325-2332 ◽  
Author(s):  
Richard J. Foreman ◽  
Stefan Emeis
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Atmospheric Boundary Layer ◽  
Drag Coefficient ◽  
Friction Velocity ◽  
Marine Boundary Layer ◽  
Marine Atmospheric Boundary Layer ◽  
Wind Speeds ◽  
Traditional Definition ◽  
Definition Of

Abstract A new functional form of the neutral drag coefficient for moderate to high wind speeds in the marine atmospheric boundary layer for a range of field measurements as reported in the literature is proposed. This new form is found to describe a wide variety of measurements recorded in the open ocean, coast, fetch-limited seas, and lakes, with almost one and the same set of parameters. This is the result of a reanalysis of the definition of the drag coefficient in the marine boundary layer, which finds that a constant is missing from the traditional definition of the drag coefficient. The constant arises because the neutral friction velocity over water surfaces is not directly proportional to the 10-m wind speed, a consequence of the transition to rough flow at low wind speeds. Within the rough flow regime, the neutral friction velocity is linearly dependent on the 10-m wind speed; consequently, within this rough regime, the new definition of the drag coefficient is not a function of the wind speed. The magnitude of the new definition of the neutral drag coefficient represents an upper limit to the magnitude of the traditional definition.

Exchange coefficients derived from GPS-sonde and SFMR measurements in hurricane conditions

2020 ◽  
Author(s):  
Olga Ermakova ◽  
Nikita Rusakov ◽  
Evgeny Poplavsky ◽  
Yuliya Troitskaya ◽  
Daniil Sergeev ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Atmospheric Boundary Layer ◽  
Moisture Transfer ◽  
Weather Forecasting ◽  
Aerodynamic Drag ◽  
Remote Sensing Data ◽  
Thermodynamic Quantities ◽  
Self Similarity ◽  
Heat And Moisture

<p>Insufficient knowledge of the atmosphere layer momentum, heat and moisture transfer between the wavy water surface and marine atmospheric boundary layer under hurricane conditions lead to the uncertainties while using weather forecasting models and models of climate. In particular, there is a significant lack of data for heat and moisture exchange coefficients. In this regard, it is necessary to analyze and process the vertical profiles of wind speed and thermodynamic quantities. The present study is concerned with the analysis and processing of measurements from the NOAA falling GPS-sondes for hurricanes of categories 4 and 5 of 2003-2017, which represent an array of data on wind speed, temperature, altitude, coordinates, etc.</p><p>The proposed approach for describing a turbulent boundary layer formed in hurricane conditions is based on the use of the self-similarity properties of the velocity and enthalpy profiles in the atmospheric boundary layer, which includes a layer of constant flows, transferring into its “wake” part with height. Based on the proposed approach, the aerodynamic drag coefficients Cd and the enthalpy exchange coefficient Ck for a selected group of hurricanes were restored. As the value of Ck/Cd represents a determining factor in the formation of a hurricane, the dependence of this ratio on the wind speed was constructed.</p><p>This work was supported by the RFBR projects No 19-05-00249, 19-05-00366, 18-35-20068 (remote sensing data analysis) and RSF No 19-17-00209 (GPS-sonde data assimilation and processing).</p>

Atmospheric boundary layer parameters retrieval from Stepped Frequency Microwave Radiometer measurements in tropical cyclones

2020 ◽  
Author(s):  
Nikita Rusakov ◽  
Evgeny Poplavsky ◽  
Olga Ermakova ◽  
Yuliya Troitskaya ◽  
Daniil Sergeev ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Microwave Radiometer ◽  
Remote Sensing Data ◽  
Field Measurements ◽  
Radar Signal ◽  
Time And Space ◽  
Sensing Data ◽  
Radar Images

<p>Active microwave sensing using satellite instruments has great advantages, since in this range the absorption by clouds and atmospheric gases is noticeably reduced, it allows for round-the-clock and all-weather monitoring of the ocean. One of the main problems is concerned with obtaining the dependency between the RCS of radar signal scattered by the wavy water surface and the parameters of the atmospheric boundary layer in hurricane conditions. To obtain this dependence, we used field measurements of wind speed in a hurricane from falling NOAA GPS-sondes and SAR images from the Sentinel-1 satellite. However, there is the problem of correct collocation of remote sensing data with field measurements of the atmospheric boundary layer parameters, since they are separated in time and space. In this regard, the amount of data suitable for analysis is very limited, which forces us to look for new data sources for processing. A six-channel SFMR radiometer is also installed on board of NOAA research aircraft that measures the emissivity of the ocean surface beneath the aircraft. Thus, it becomes possible to relate the radiometric measurements of SFMR with the parameters of the atmospheric boundary layer in a tropical cyclone obtained from wind velocity profiles, since they are carried out as close as possible in time and space. Using this relation, the SFMR data and the hurricane radar images were analyzed together and an alternative method was found for constructing the dependence of the RCS on the parameters of the boundary layer.</p><p>This work was supported by the RFBR projects No. 19-05-00249, 19-05-00366, 18-35-20068 (remote sensing data analysis) and RSF No. 19-17-00209 (GPS-sondes data assimilation and processing).</p><p> </p>

On the use of cross-polarized SAR and GPS-sonde measurements for wind speed retrieval in tropical cyclones

2020 ◽  
Author(s):  
Evgeny Poplavsky ◽  
Nikita Rusakov ◽  
Olga Ermakova ◽  
Yuliya Troitskaya ◽  
Daniil Sergeev ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Boundary Layer ◽  
Wind Speed ◽  
Atmospheric Boundary Layer ◽  
Remote Sensing Data ◽  
Field Measurements ◽  
Cross Polarization ◽  
Sar Images ◽  
Sensing Data ◽  
High Level

<p>The current investigation is concerned with the study of the dependence of the scattered cross-polarized microwave signal from the Sentinel-1 satellite on the parameters of the marine atmospheric boundary layer based on data obtained from falling NOAA GPS-sondes under tropical cyclone conditions.<br>Field measurements and remote sensing data for hurricanes in the Atlantic and Pacific oceans were analyzed for the period 2016 - 2018. Based on the analysis of data measured by GPS-sondes, averaged wind speed profiles were obtained, while the parameters of the atmospheric boundary layer (drag coefficient and wind friction velocity) were retrieved using the self-similarity property of velocity profiles from measurements in the “wake” part.<br>Sentinel-1 SAR images were used as remote sensing data. Images with cross polarization have a high level of thermal noise (NESZ), which leads to errors when retrieving the NRCS. In this regard, preliminary image processing was performed in the SNAP application.<br>Using the obtained parameters of the atmospheric boundary layer, the data of GRS-sonde measurements and Sentinel-1 SAR images on cross polarization were collocated and the dependences of the NRCS on the parameters of the atmospheric boundary layer were obtained.</p><div>This work was supported by the RFBR projects No. 19-05-00249, 19-05-00366, 18-35-20068 (remote sensing data analysis) and RSF No. 19-17-00209 (GPS-sondes data assimilation and processing).</div>

scholarly journals Integrated System for Atmospheric Boundary Layer Height Estimation (ISABLE) using a ceilometer and microwave radiometer

2020 ◽  
Vol 13 (12) ◽  
pp. 6965-6987
Author(s):  
Jae-Sik Min ◽  
Moon-Soo Park ◽  
Jung-Hoon Chae ◽  
Minsoo Kang
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Layer Structure ◽  
Microwave Radiometer ◽  
Accurate Determination ◽  
Integrated System ◽  
Lapse Rate ◽  
High Temporal Resolution ◽  
Near Surface ◽  
Boundary Layer Structure

Abstract. Accurate boundary layer structure and height are critical in the analysis of the features of air pollutants and local circulation. Although surface-based remote sensing instruments provide a high temporal resolution of the boundary layer structure, there are numerous uncertainties in terms of the accurate determination of the atmospheric boundary layer heights (ABLHs). In this study, an algorithm for an integrated system for ABLH estimation (ISABLE) was developed and applied to the vertical profile data obtained using a ceilometer and a microwave radiometer in Seoul city, Korea. A maximum of 19 ABLHs were estimated via the conventional time-variance, gradient, wavelet, and clustering methods using the backscatter coefficient from the ceilometer. Meanwhile, several stable boundary layer heights were extracted through near-surface inversion and environmental lapse rate methods using the potential temperature from the microwave radiometer. The ISABLE algorithm can find an optimal ABLH from post-processing, such as k-means clustering and density-based spatial clustering of applications with noise (DBSCAN) techniques. It was found that the ABLH determined using ISABLE exhibited more significant correlation coefficients and smaller mean bias and root mean square error between the radiosonde-derived ABLHs than those obtained using the most conventional methods. Clear skies exhibited higher daytime ABLH than cloudy skies, and the daily maximum ABLH was recorded in summer because of the more intense radiation. The ABLHs estimated by ISABLE are expected to contribute to the parameterization of vertical diffusion in the atmospheric boundary layer.

scholarly journals Stable Atmospheric Boundary Layers and Diurnal Cycles: Challenges for Weather and Climate Models

2013 ◽  
Vol 94 (11) ◽  
pp. 1691-1706 ◽  
Author(s):  
A. A. M. Holtslag ◽  
G. Svensson ◽  
P. Baas ◽  
S. Basu ◽  
B. Beare ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Atmospheric Boundary Layer ◽  
Climate Models ◽  
Model Performance ◽  
Weather Forecast ◽  
The Arctic ◽  
Diurnal Cycles ◽  
Low Wind Speed ◽  
Weather And Climate

The representation of the atmospheric boundary layer is an important part of weather and climate models and impacts many applications such as air quality and wind energy. Over the years, the performance in modeling 2-m temperature and 10-m wind speed has improved but errors are still significant. This is in particular the case under clear skies and low wind speed conditions at night as well as during winter in stably stratified conditions over land and ice. In this paper, the authors review these issues and provide an overview of the current understanding and model performance. Results from weather forecast and climate models are used to illustrate the state of the art as well as findings and recommendations from three intercomparison studies held within the Global Energy and Water Exchanges (GEWEX) Atmospheric Boundary Layer Study (GABLS). Within GABLS, the focus has been on the examination of the representation of the stable boundary layer and the diurnal cycle over land in clear-sky conditions. For this purpose, single-column versions of weather and climate models have been compared with observations, research models, and large-eddy simulations. The intercomparison cases are based on observations taken in the Arctic, Kansas, and Cabauw in the Netherlands. From these studies, we find that even for the noncloudy boundary layer important parameterization challenges remain.

Evaluation of regional NWP results for sea ice covered Bothnia Bay (Baltic Sea) in winter 2020.

2021 ◽  
Author(s):  
Marta Wenta ◽  
Agnieszka Herman
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Sea Ice ◽  
Surface Temperature ◽  
Atmospheric Boundary Layer ◽  
Baltic Sea ◽  
Polar Regions ◽  
Near Surface ◽  
Accurate Representation ◽  
Complex Processes

<p>The ongoing development of NWP (Numerical Weather Prediction) models and their increasing horizontal resolution have significantly improved forecasting capabilities. However, in the polar regions models struggle with the representation of near-surface atmospheric properties and the vertical structure of the atmospheric boundary layer (ABL) over sea ice. Particularly difficult to resolve are near-surface temperature, wind speed, and humidity, along with diurnal changes of those properties. Many of the complex processes happening at the interface of sea ice and atmosphere, i.e. vertical fluxes, turbulence, atmosphere - surface coupling are poorly parameterized or not represented in the models at all. Limited data coverage and our poor understanding of the complex processes taking place in the polar ABL limit the development of suitable parametrizations. We try to contribute to the ongoing effort to improve the forecast skill in polar regions through the analysis of unmanned aerial vehicles (UAVs) and automatic weather station (AWS) atmospheric measurements from the coastal area of Bothnia Bay (Wenta et. al., 2021), and the application of those datasets for the analysis of regional NWP models' forecasts. </p><p>Data collected during HAOS (Hailuoto Atmospheric Observations over Sea ice) campaign (Wenta et. al., 2021) is used for the evaluation of regional NWP models results from AROME (Applications of Research to Operations at Mesoscale) - Arctic, HIRLAM (High Resolution Limited Area Model) and WRF (Weather Research and Forecasting). The presented analysis focuses on 27 Feb. 2020 - 2 Mar. 2020, the time of the HAOS campaign, shortly after the formation of new, thin sea ice off the westernmost point of Hailuoto island.  Throughout the studied period weather conditions changed from very cold (-14℃), dry and cloud-free to warmer (~ -5℃), more humid and opaquely cloudy. We evaluate models’ ability to correctly resolve near-surface temperature, humidity, and wind speed, along with vertical changes of temperature and humidity over the sea ice. It is found that generally, models struggle with an accurate representation of surface-based temperature inversions, vertical variations of humidity, and temporal wind speed changes. Furthermore, a WRF Single Columng Model (SCM) is launched to study whether specific WRF planetary boundary layer parameterizations (MYJ, YSU, MYNN, QNSE), vertical resolution, and more accurate representation of surface conditions increase the WRF model’s ability to resolve the ABL above sea ice in the Bay of Bothnia. Experiments with WRF SCM are also used to determine the possible reasons behind model’s biases. Preliminary results show that accurate representation of sea ice conditions, including thickness, surface temperature, albedo, and snow coverage is crucial for increasing the quality of NWP models forecasts. We emphasize the importance of further development of parametrizations focusing on the processes at the sea ice-atmosphere interface.</p><p> </p><p>Reference:</p><p>Wenta, M., Brus, D., Doulgeris, K., Vakkari, V., and Herman, A.: Winter atmospheric boundary layer observations over sea ice in the coastal zone of the Bay of Bothnia (Baltic Sea), Earth Syst. Sci. Data, 13, 33–42, https://doi.org/10.5194/essd-13-33-2021, 2021. </p><p><br><br><br><br><br><br></p>

Estimating local seeing at Observatorio Astronómico Nacional in San Pedro Mártir using CFD simulations of the atmospheric boundary layer

2020 ◽  
Vol 496 (4) ◽  
pp. 5552-5563
Author(s):  
R Sánchez García ◽  
M G Richer ◽  
R Gómez Martínez ◽  
R Avila
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Atmospheric Boundary Layer ◽  
Vertical Profile ◽  
Structure Constant ◽  
Index Of Refraction ◽  
San Pedro ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
Sierra San Pedro Martir

ABSTRACT We present computational fluid dynamics simulations of the atmospheric boundary layer (ABL) at the Observatorio Astronómico Nacional in the Sierra San Pedro Mártir (OAN-SPM) whose objective is to model the seeing observed at the site. We constrain the simulations using observations of the seeing, the vertical profile of the wind speed, and the vertical profile of the temperature, the first two resolved as a function of wind direction. We successfully model the seeing observed under typical wind conditions for each direction by adopting input profiles of the wind speed, the turbulent kinetic energy, and the energy dissipation. The resulting vertical profiles of the index of refraction structure constant are qualitatively similar to the mean profile derived from studies at the site.

scholarly journals Wind speed acceleration around a single low solid roughness in atmospheric boundary layer

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Lin-Tao Fu ◽  
Qing Fan ◽  
Zong-Liu Huang
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Atmospheric Boundary Layer
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