Variance Characteristics of Tropical Radiosonde Winds Using a Vector-Tensor Method
In this paper, an exploratory study on the variance characteristics of upper-air winds in a near-equator monsoon region is presented. The data were obtained from historical radiosonde observations from up to 250 stations within the region of interest for the period between 1954 and 2013. An alternat...
| Main Authors: | , , , |
|---|---|
| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2018
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/89389 http://hdl.handle.net/10220/44875 |
| _version_ | 1811685471126814720 |
|---|---|
| author | Tieo, Jing-Jin Koh, Tieh-Yong Skote, Martin Srikanth, Narasimalu |
| author2 | Interdisciplinary Graduate School (IGS) |
| author_facet | Interdisciplinary Graduate School (IGS) Tieo, Jing-Jin Koh, Tieh-Yong Skote, Martin Srikanth, Narasimalu |
| author_sort | Tieo, Jing-Jin |
| collection | NTU |
| description | In this paper, an exploratory study on the variance characteristics of upper-air winds in a near-equator monsoon region is presented. The data were obtained from historical radiosonde observations from up to 250 stations within the region of interest for the period between 1954 and 2013. An alternative method based on vector statistics was employed in this study which characterises the mean by a vector and the variance by a tensor. Unlike the conventional approach of using scalar wind speeds, this vector-tensor approach allows the directional properties of the variance to be studied. A suite of statistics to describe the geometric properties of the variance tensor was also developed. These characterise the size of the variance, its degree of anisotropy, and the alignment of the preferred direction (if anisotropy is present) with the direction of the mean wind vector. Through analysis of these statistics, several salient trends were observed for the middle troposphere. It was found that the variance size and anisotropy exhibit significant variation with height whereas the alignment with the mean vector varies with the mean wind magnitude instead. It was also found that the scalar variance increases with mean wind speed. |
| first_indexed | 2024-10-01T04:45:03Z |
| format | Journal Article |
| id | ntu-10356/89389 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T04:45:03Z |
| publishDate | 2018 |
| record_format | dspace |
| spelling | ntu-10356/893892021-01-08T02:57:23Z Variance Characteristics of Tropical Radiosonde Winds Using a Vector-Tensor Method Tieo, Jing-Jin Koh, Tieh-Yong Skote, Martin Srikanth, Narasimalu Interdisciplinary Graduate School (IGS) School of Mechanical and Aerospace Engineering Energy Research Institute @ NTU (ERI@N) Variance Wind Characteristics In this paper, an exploratory study on the variance characteristics of upper-air winds in a near-equator monsoon region is presented. The data were obtained from historical radiosonde observations from up to 250 stations within the region of interest for the period between 1954 and 2013. An alternative method based on vector statistics was employed in this study which characterises the mean by a vector and the variance by a tensor. Unlike the conventional approach of using scalar wind speeds, this vector-tensor approach allows the directional properties of the variance to be studied. A suite of statistics to describe the geometric properties of the variance tensor was also developed. These characterise the size of the variance, its degree of anisotropy, and the alignment of the preferred direction (if anisotropy is present) with the direction of the mean wind vector. Through analysis of these statistics, several salient trends were observed for the middle troposphere. It was found that the variance size and anisotropy exhibit significant variation with height whereas the alignment with the mean vector varies with the mean wind magnitude instead. It was also found that the scalar variance increases with mean wind speed. Published version 2018-05-23T05:14:19Z 2019-12-06T17:24:25Z 2018-05-23T05:14:19Z 2019-12-06T17:24:25Z 2018 Journal Article Tieo, J.-J., Koh, T.-Y., Skote, M., & Srikanth, N. (2018). Variance Characteristics of Tropical Radiosonde Winds Using a Vector-Tensor Method. Energies, 11(1), 137-. 1996-1073 https://hdl.handle.net/10356/89389 http://hdl.handle.net/10220/44875 10.3390/en11010137 en Energies © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). 22 p. application/pdf |
| spellingShingle | Variance Wind Characteristics Tieo, Jing-Jin Koh, Tieh-Yong Skote, Martin Srikanth, Narasimalu Variance Characteristics of Tropical Radiosonde Winds Using a Vector-Tensor Method |
| title | Variance Characteristics of Tropical Radiosonde Winds Using a Vector-Tensor Method |
| title_full | Variance Characteristics of Tropical Radiosonde Winds Using a Vector-Tensor Method |
| title_fullStr | Variance Characteristics of Tropical Radiosonde Winds Using a Vector-Tensor Method |
| title_full_unstemmed | Variance Characteristics of Tropical Radiosonde Winds Using a Vector-Tensor Method |
| title_short | Variance Characteristics of Tropical Radiosonde Winds Using a Vector-Tensor Method |
| title_sort | variance characteristics of tropical radiosonde winds using a vector tensor method |
| topic | Variance Wind Characteristics |
| url | https://hdl.handle.net/10356/89389 http://hdl.handle.net/10220/44875 |
| work_keys_str_mv | AT tieojingjin variancecharacteristicsoftropicalradiosondewindsusingavectortensormethod AT kohtiehyong variancecharacteristicsoftropicalradiosondewindsusingavectortensormethod AT skotemartin variancecharacteristicsoftropicalradiosondewindsusingavectortensormethod AT srikanthnarasimalu variancecharacteristicsoftropicalradiosondewindsusingavectortensormethod |