A Study of Atmospheric Temperature and Wind Profiles Obtained from Rocketsondes in the Chinese Midlatitude Region

AbstractIn November 2004, five TK-1 meteorological rockets were launched at Jiuquan Satellite Launch Center in China for the first time. The observations are compared with models, reanalysis, and satellite datasets. The mean differences of temperature between the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) and the rocketsondes are about 0.7–2.4 K in the stratosphere and −6 K in the mesosphere. The temperature biases between the Naval Research Laboratory Mass Spectrometer and Incoherent Scatter Radar, Exosphere (NRLMSISE-00)/Whole Atmosphere Community Climate Model (WACCM), and the rocketsondes are small (~1–2 K) in the lower stratosphere and largest near the stratopause. Both models strongly overestimated the temperature by 11 K on average. The discrepancies of horizontal winds between the Horizontal Wind Model 07 (HWM07)/WACCM and the rocketsondes reached the maximum in the upper stratosphere and the lower mesosphere. The westerly observed zonal winds and equatorward meridional winds were two interesting phenomena that led to large biases in the upper stratosphere, which need further study.

Download Full-text

FPI observations of nighttime mesospheric and thermospheric winds in China and their comparisons with HWM07

Annales Geophysicae ◽

10.5194/angeo-31-1365-2013 ◽

2013 ◽

Vol 31 (8) ◽

pp. 1365-1378 ◽

Cited By ~ 18

Author(s):

W. Yuan ◽

X. Liu ◽

J. Xu ◽

Q. Zhou ◽

G. Jiang ◽

...

Keyword(s):

Zonal Wind ◽

Annual Variation ◽

Middle Atmosphere ◽

Geomagnetic Latitude ◽

Meridional Wind ◽

Central China ◽

Horizontal Wind ◽

Zonal Winds ◽

Meridional Winds ◽

First Time

Abstract. We analyzed the nighttime horizontal neutral winds in the middle atmosphere (~ 87 and ~ 98 km) and thermosphere (~ 250 km) derived from a Fabry–Perot interferometer (FPI), which was installed at Xinglong station (40.2° N, 117.4° E) in central China. The wind data covered the period from April 2010 to July 2012. We studied the annual, semiannual and terannual variations of the midnight winds at ~ 87 km, ~ 98 km and ~ 250 km for the first time and compared them with Horizontal Wind Model 2007 (HWM07). Our results show the following: (1) at ~ 87 km, both the observed and model zonal winds have similar phases in the annual and semiannual variations. However, the HWM07 amplitudes are much larger. (2) At ~ 98 km, the model shows strong eastward wind in the summer solstice, resulting in a large annual variation, while the observed strongest component is semiannual. The observation and model midnight meridional winds agree well. Both are equatorward throughout the year and have small amplitudes in the annual and semiannual variations. (3) There are large discrepancies between the observed and HWM07 winds at ~ 250 km. This discrepancy is largely due to the strong semiannual zonal wind in the model and the phase difference in the annual variation of the meridional wind. The FPI annual variation coincides with the results from Arecibo, which has similar geomagnetic latitude as Xinglong station. In General, the consistency of FPI winds with model winds is better at ~ 87 and ~ 98 km than that at ~ 250 km. We also studied the seasonally and monthly averaged nighttime winds. The most salient features include the following: (1) the seasonally averaged zonal winds at ~ 87 and ~ 98 km typically have small variations throughout the night. (2) The model zonal and meridional nighttime wind variations are typically much larger than those of observations at ~ 87 km and ~ 98 km. (3) At ~ 250 km, model zonal wind compares well with the observation in the winter. For spring and autumn, the model wind is more eastward before ~ 03:00 LT but more westward after. The observed nighttime zonal and meridional winds on average are close to zero in the summer and autumn, which indicates a lack of strong stable tides. The consistency of FPI zonal wind with model wind at ~ 250 km is better than the meridional wind.

Download Full-text

Derivation of gravity wave intrinsic parameters and vertical wavelength using a single scanning OH(3-1) airglow spectrometer

Atmospheric Measurement Techniques ◽

10.5194/amt-11-2937-2018 ◽

2018 ◽

Vol 11 (5) ◽

pp. 2937-2947 ◽

Cited By ~ 3

Author(s):

Sabine Wüst ◽

Thomas Offenwanger ◽

Carsten Schmidt ◽

Michael Bittner ◽

Christoph Jacobi ◽

...

Keyword(s):

Gravity Wave ◽

Gravity Waves ◽

Spatial Information ◽

Rotational Transition ◽

Horizontal Wind ◽

Vertical Temperature ◽

Vertical Wavelength ◽

Broadband Emission ◽

Wind Measurements ◽

First Time

Abstract. For the first time, we present an approach to derive zonal, meridional, and vertical wavelengths as well as periods of gravity waves based on only one OH* spectrometer, addressing one vibrational-rotational transition. Knowledge of these parameters is a precondition for the calculation of further information, such as the wave group velocity vector. OH(3-1) spectrometer measurements allow the analysis of gravity wave ground-based periods but spatial information cannot necessarily be deduced. We use a scanning spectrometer and harmonic analysis to derive horizontal wavelengths at the mesopause altitude above Oberpfaffenhofen (48.09∘ N, 11.28∘ E), Germany for 22 nights in 2015. Based on the approximation of the dispersion relation for gravity waves of low and medium frequencies and additional horizontal wind information, we calculate vertical wavelengths. The mesopause wind measurements nearest to Oberpfaffenhofen are conducted at Collm (51.30∘ N, 13.02∘ E), Germany, ca. 380 km northeast of Oberpfaffenhofen, by a meteor radar. In order to compare our results, vertical temperature profiles of TIMED-SABER (thermosphere ionosphere mesosphere energetics dynamics, sounding of the atmosphere using broadband emission radiometry) overpasses are analysed with respect to the dominating vertical wavelength.

Download Full-text

The Effects of Background Zonal and Meridional Winds on ENSO in a Coupled GCM

Journal of Climate ◽

10.1175/jcli-d-18-0822.1 ◽

2020 ◽

Vol 33 (6) ◽

pp. 2075-2091 ◽

Cited By ~ 2

Author(s):

Bowen Zhao ◽

Alexey Fedorov

Keyword(s):

Zonal Wind ◽

El Niño ◽

Climate Model ◽

El Nino ◽

Meridional Wind ◽

Wind Component ◽

Coupled Models ◽

Positive Feedbacks ◽

Zonal Winds ◽

Meridional Winds

AbstractChanges in background zonal wind in the tropical Pacific are often invoked to explain changes in ENSO properties. However, the sensitivity of ENSO to mean zonal winds has been thoroughly explored only in intermediate coupled models (following Zebiak and Cane), not in coupled GCMs. The role of mean meridional winds has received even less attention. Accordingly, the goal of this study is to examine systematically the effects of both zonal (equatorial) and meridional (cross-equatorial) background winds on ENSO using targeted experiments with a comprehensive climate model (CESM). Changes in the mean winds are generated by imposing heat flux forcing in two confined regions at a sufficient distance north and south of the equator. We find that the strengthening of either wind component reduces ENSO amplitude, especially eastern Pacific SST variability, and inhibits meridional swings of the intertropical convergence zone (ITCZ). The effect of zonal winds is generally stronger than that of meridional winds. A stability analysis reveals that the strengthening of zonal and meridional winds weakens the ENSO key positive feedbacks, specifically the zonal advection and thermocline feedbacks, which explains these changes. Zonal wind enhancement also intensifies mean upwelling and hence dynamical damping, leading to a further weakening of El Niño events. Ultimately, this study argues that the zonal and, to a lesser extent, meridional wind strengthening of the past decades may have contributed to the observed shift of El Niño characteristics after the year 2000.

Download Full-text

Seasonal variations in the horizontal wind structure from 0–100 km above Rothera station, Antarctica (67° S, 68° W)

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-5-4291-2005 ◽

2005 ◽

Vol 5 (4) ◽

pp. 4291-4310 ◽

Cited By ~ 1

Author(s):

R. E. Hibbins ◽

J. D. Shanklin ◽

P. J. Espy ◽

M. J. Jarvis ◽

D. M. Riggin ◽

...

Keyword(s):

Lower Thermosphere ◽

Model Atmosphere ◽

Horizontal Wind ◽

Zero Crossing ◽

Zonal Winds ◽

Wind Structure ◽

Falling Sphere ◽

Wind Climatology ◽

Meridional Winds ◽

Summer Time

Abstract. A medium frequency spaced-antenna radar has been operating at Rothera station, Antarctica (67° S, 68° W) for two periods, between 1997–1998 and since 2002, measuring winds in the mesosphere and lower thermosphere. In this paper monthly mean winds are derived and presented along with three years of radiosonde balloon data for comparison with the HWM-93 model atmosphere and other high latitude southern hemisphere sites. The observed meridional winds are slightly more northwards than those predicted by the model above 80 km in the winter months and below 80 km in summer. In addition, the altitude of the summer time zero crossing of the zonal winds above the westward jet is overestimated by the model by up to 8 km. These data are then merged with the wind climatology obtained from falling sphere measurements made during the PORTA campaign at Rothera in early 1998 and the HWM-93 model atmosphere to generate a complete zonal wind climatology between 0 and 100 km as a benchmark for future studies at Rothera. A westwards (eastwards) maximum of 44 ms−1 at 67 km altitude occurs in mid December (62 ms−1 at 37 km in mid July). The 0 ms−1 wind contour reaches a maximum altitude of 90 km in mid November and a minimum altitude of 18 km in January extending into mid March at 75 km and early October at 76 km.

Download Full-text

Measurement of horizontal wind profiles in the polar stratosphere and mesosphere using ground based observations of ozone and carbon monoxide lines in the 230–250 GHz region: Proof of concept

10.5194/amt-2015-406 ◽

2016 ◽

Author(s):

D. A. Newnham ◽

G. P. Ford ◽

T. Moffat-Griffin ◽

H. C. Pumphrey

Keyword(s):

Carbon Monoxide ◽

Meridional Wind ◽

Frequency Resolution ◽

Horizontal Wind ◽

Data Sets ◽

Atmospheric Emission ◽

Millimetre Wave ◽

Meridional Winds ◽

System Temperature ◽

Wind Profiles

Abstract. Meteorological and atmospheric models are being extended up to 80 km altitude but there are very few observing techniques that can measure stratospheric-mesospheric winds at altitudes between 20 km and 80 km to verify model data-sets. Here we demonstrate the feasibility of horizontal wind profile measurements using ground-based passive millimetre-wave spectroradiometric observations of ozone lines centred at 231.28 GHz, 249.79 GHz, and 249.96 GHz. Vertical profiles of horizontal winds are retrieved from forward and inverse modelling simulations of the line-of-sight Doppler-shifted atmospheric emission lines above Halley station (75°37’S, 26°14’W), Antarctica. For a radiometer with a system temperature of 1400 K and 30 kHz spectral resolution observing the ozone 231.28 GHz line we estimate that 12hr zonal and meridional wind profiles could be determined over the altitude range 25–74 km in winter, and 28–66 km in summer. Height-dependent measurement uncertainties are in the range 3–8 m s–1 and vertical resolution ~8–16 km. Under optimum observing conditions at Halley a temporal resolution of 1.5hrs for measuring either zonal or meridional winds is possible, reducing to 0.5hr for a radiometer with a 700 K system temperature. Combining observations of the 231.28 GHz ozone line and the 230.54 GHz carbon monoxide line gives additional altitude coverage at 85±12 km. The effects of clear-sky seasonal mean winter/summer conditions, zenith angle of the received atmospheric emission, and spectrometer frequency resolution on the altitude coverage, measurement uncertainty, and height and time resolution of the retrieved wind profiles have been determined.

Download Full-text

Seasonal variations in the horizontal wind structure from 0-100 km above Rothera station, Antarctica (67° S, 68° W)

Atmospheric Chemistry and Physics ◽

10.5194/acp-5-2973-2005 ◽

2005 ◽

Vol 5 (11) ◽

pp. 2973-2980 ◽

Cited By ~ 17

Author(s):

R. E. Hibbins ◽

J. D. Shanklin ◽

P. J. Espy ◽

M. J. Jarvis ◽

D. M. Riggin ◽

...

Keyword(s):

Lower Thermosphere ◽

Model Atmosphere ◽

Horizontal Wind ◽

Zero Crossing ◽

Zonal Winds ◽

Wind Structure ◽

Falling Sphere ◽

Wind Climatology ◽

Meridional Winds ◽

Summer Time

Abstract. A medium frequency spaced-antenna radar has been operating at Rothera station, Antarctica (67° S, 68° W) for two periods, between 1997-1998 and since 2002, measuring winds in the mesosphere and lower thermosphere. In this paper monthly mean winds are derived and presented along with three years of radiosonde balloon data for comparison with the HWM-93 model atmosphere and other high latitude southern hemisphere sites. The observed meridional winds are slightly more northwards than those predicted by the model above 80 km in the winter months and below 80 km in summer. In addition, the altitude of the summer time zero crossing of the zonal winds above the westward jet is overestimated by the model by up to 8 km. These data are then merged with the wind climatology obtained from falling sphere measurements made during the PORTA campaign at Rothera in early 1998 and the HWM-93 model atmosphere to generate a complete zonal wind climatology between 0 and 100 km as a benchmark for future studies at Rothera. A westwards (eastwards) maximum of 44 ms-1 at 67 km altitude occurs in mid December (62 ms-1 at 37 km in mid July). The 0 ms-1 wind contour reaches a maximum altitude of 90 km in mid November and a minimum altitude of 18 km in January extending into mid March at 75 km and early October at 76 km.

Download Full-text

Mitigation of bias sources for atmospheric temperature and humidity in the mobile Raman Weather and Aerosol Lidar (WALI)

Atmospheric Measurement Techniques ◽

10.5194/amt-14-7525-2021 ◽

2021 ◽

Vol 14 (12) ◽

pp. 7525-7544

Author(s):

Julien Totems ◽

Patrick Chazette ◽

Alexandre Baron

Keyword(s):

Water Vapor ◽

Measurement Errors ◽

Weather Prediction ◽

Atmospheric Temperature ◽

Temperature Profiles ◽

Optical Elements ◽

Common Path ◽

Calibration Uncertainty ◽

Mean Differences ◽

First Time

Abstract. Lidars using vibrational and rotational Raman scattering to continuously monitor both the water vapor and temperature profiles in the low and middle troposphere offer enticing perspectives for applications in weather prediction and studies of aerosol–cloud–water vapor interactions by simultaneously deriving relative humidity and atmospheric optical properties. Several heavy systems exist in European laboratories, but only recently have they been downsized and ruggedized for deployment in the field. In this paper, we describe in detail the technical choices made during the design and calibration of the new Raman channels for the mobile Weather and Aerosol Lidar (WALI), going over the important sources of bias and uncertainty on the water vapor and temperature profiles stemming from the different optical elements of the instrument. For the first time, the impacts of interference filters and non-common-path differences between Raman channels, and their mitigation, in particular are investigated, using horizontal shots in a homogeneous atmosphere. For temperature, the magnitude of the highlighted biases can be much larger than the targeted absolute accuracy of 1 ∘C defined by the WMO (up to 6 ∘C bias below 300 m range). Measurement errors are quantified using simulations and a number of radiosoundings launched close to the laboratory. After de-biasing, the remaining mean differences are below 0.1 g kg−1 on water vapor and 1 ∘C on temperature, and rms differences are consistent with the expected error from lidar noise, calibration uncertainty, and horizontal inhomogeneities of the atmosphere between the lidar and radiosondes.

Download Full-text

Climatology of thermospheric neutral winds over Oukaïmeden Observatory in Morocco

Annales Geophysicae ◽

10.5194/angeo-35-161-2017 ◽

2017 ◽

Vol 35 (1) ◽

pp. 161-170 ◽

Cited By ~ 8

Author(s):

Mohamed Kaab ◽

Zouhair Benkhaldoun ◽

Daniel J. Fisher ◽

Brian Harding ◽

Aziza Bounhir ◽

...

Keyword(s):

Dissociative Recombination ◽

Horizontal Wind ◽

Wind Model ◽

Neutral Winds ◽

Zonal Winds ◽

Early Evening ◽

Atlas Mountains ◽

Fabry Perot ◽

Meridional Winds ◽

High Atlas Mountains

Abstract. In order to explore coupling between the thermosphere and ionosphere and to address the lack of data relating to thermospheric neutral winds and temperatures over the African sector, a new system of instruments was installed at the Oukaïmeden Observatory located in the high Atlas Mountains, 75 km south of Marrakesh, Morocco (31.206° N, 7.866° W, 22.84° N magnetic). In this work we present the first multi-year results of the climatology of meridional and zonal winds obtained during the period from January 2014 to February 2016, including observations from 648 nights. The measurements are obtained using an imaging Fabry–Pérot interferometer, which measures the 630.0 nm emissions caused by dissociative recombination of O2+. The basic climatology of the winds is as expected, showing zonal winds that are strongly eastward in the early evening just after sunset with a speed of 50 to 100 m s−1 decreasing in magnitude, and reversing directions in the local summer months, towards sunrise. The meridional winds are slightly poleward in the early evening during the local winter, before reversing directions around 21:00 LT. In the local summer months, the meridional winds are equatorward for the entire night, reaching a maximum equatorward speed of 75 m s−1. We compare the observed climatologies of neutral winds to that provided by the recently updated Horizontal Wind Model (HWM14) in order to validate that model's predictions of the thermospheric wind patterns over the eastern portion of Africa. The model captures much of the features in the observational climatologies. The most notable exception is for the zonal winds during local summer, when the maximum eastward wind in the observations occurs approximately 4 h later than seen in the model results.

Download Full-text

Derivation of horizontal and vertical wavelengths using a scanning OH(3-1) airglow spectrometer

10.5194/amt-2017-350 ◽

2017 ◽

Cited By ~ 1

Author(s):

Sabine Wüst ◽

Thomas Offenwanger ◽

Carsten Schmidt ◽

Michael Bittner ◽

Christoph Jacobi ◽

...

Keyword(s):

Gravity Waves ◽

Spatial Information ◽

Rotational Transition ◽

Horizontal Wind ◽

Vertical Temperature ◽

Medium Frequency ◽

Vertical Wavelength ◽

Broadband Emission ◽

Wind Measurements ◽

First Time

Abstract. For the first time, we present an approach to derive zonal, meridional and vertical wavelengths as well as periods of gravity waves based on only one OH* spectrometer addressing one vibrational-rotational transition. Knowledge of these parameters is a precondition for the calculation of further information such as the wave group velocity vector. OH(3-1) spectrometer measurements allow the analysis of gravity wave periods, but spatial information cannot necessarily be deduced. We use a scanning spectrometer and the harmonic analysis to derive horizontal wavelengths at the mesopause above Oberpfaffenhofen (48.09 °N, 11.28 °E), Germany for 22 nights in 2015. Based on the approximation of the dispersion relation for gravity waves of low and medium frequency and additional horizontal wind information, we calculate vertical wavelengths afterwards. The mesopause wind measurements nearest to Oberpfaffenhofen are conducted at Collm (51.30 °N, 13.02 °E), Germany, ca. 380 km northeast of Oberfpaffenhofen by a meteor radar. In order to check our results, vertical temperature profiles of TIMED-SABER (Thermosphere Ionosphere Mesosphere Energetics Dynamics, Sounding of the Atmosphere using Broadband Emission Radiometry) overpasses are analysed with respect to the dominating vertical wavelength.

Download Full-text

Investigation of sources of gravity waves observed in the Brazilian equatorial region on 8 April 2005

Annales Geophysicae ◽

10.5194/angeo-38-507-2020 ◽

2020 ◽

Vol 38 (2) ◽

pp. 507-516 ◽

Cited By ~ 1

Author(s):

Oluwakemi Dare-Idowu ◽

Igo Paulino ◽

Cosme A. O. B. Figueiredo ◽

Amauri F. Medeiros ◽

Ricardo A. Buriti ◽

...

Keyword(s):

Ray Tracing ◽

Gravity Waves ◽

Spectral Characteristics ◽

Phase Speed ◽

Radar Data ◽

Equatorial Region ◽

Horizontal Wind ◽

Naval Research ◽

Wind Profiles ◽

The Waves

Abstract. On 8 April 2005, strong gravity wave (GW) activity (over a period of more than 3 h) was observed in São João do Cariri (7.4∘ S, 36.5∘ W). These waves propagated to the southeast and presented different spectral characteristics (wavelength, period and phase speed). Using hydroxyl (OH) airglow images, the characteristics of the observed GWs were calculated; the wavelengths ranged between 90 and 150 km, the periods ranged from ∼26 to 67 min and the phase speeds ranged from 32 to 71 m s−1. A reverse ray-tracing analysis was performed to search for the possible sources of the waves that were detected. The ray-tracing database was composed of temperature profiles from the Naval Research Laboratory Mass Spectrometer Incoherent Scatter (NRLMSISE-00) model and SABER measurements as well as wind profiles from the Horizontal Wind Model (HWM) and meteor radar data. According to the ray tracing result, the likely source of these observed gravity waves was the Intertropical Convergence Zone, which caused intense convective processes to take place in the northern part of the observatory. Also, the observed preferential propagation direction of the waves to the southeast could be explained using blocking diagrams, i.e. due to the wind filtering process.

Download Full-text