+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Comparisons of Thermospheric Wind and Temperature Measurements in Equatorial Brazil to Whole Atmosphere Model Predictions

Comparisons of Thermospheric Wind and Temperature Measurements in Equatorial Brazil to Whole Atmosphere Model Predictions

Journal of Atmospheric and Solar-Terrestrial Physics 103: 103-112

The results from the Whole Atmosphere Model (WAM) at 240km are compared with measurements of equatorial thermospheric winds and temperatures acquired by nearly continual nighttime Fabry-Perot interferometer (FPI) measurements made in northeastern Brazil from September 2009 to August 2012. These comparisons show generally good agreement for the zonal winds with only slight differences seen in regard to the early morning period. For the evening period of 21 23 LT the observed meridional winds differed from the WAM predictions in two respects. First, while the flow direction was generally correct, the speeds of observed cross-hemispheric flow from the summer to the winter hemisphere were generally somewhat greater by 25 to 35ms?1 than the predicted speeds from WAM. In contrast, the observed meridional winds are found to be weaker than the WAM results for winter months for all three years. Second, although the observations and predictions both show similar timing and amplitude for a three-hour period of northward flow in September and October, the observations indicate a shift in the timing of this flow of about one hour, from ?22 LT in September and October to ?21 LT in December. The WAM predictions show a systematic shift in phase from 21-00 LT in September to 18 21 LT in December. Regarding temperature, the WAM predictions show a midnight temperature maximum (MTM) with a peak amplitude of 50 65K, in agreement with the observations. However, the WAM results also show a systematic shift in timing of the MTM occurrence, with the MTM peak seen at ?22 LT in summer and at 00 LT in winter. In contrast, the FPI monthly climatology data show the timing of the MTM peak to be 00 0.5 LT for all months except winter, when the MTM peak is not clearly evident.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 036852572

Download citation: RISBibTeXText

DOI: 10.1016/j.jastp.2013.04.002

Related references

Equatorial Thermospheric Wind Changes During the Solar Cycle: Measurements at Arequipa, Peru, From 1983 to 1990. Journal of Geophysical Research 96(0): 15917-15930, 1991

Interdecadal sea surface temperature variability in the equatorial Pacific Ocean Part II The role of equatorial/off-equatorial wind stresses in a hybrid coupled model. Journal Of Climate: 17, 4242-4256, 2008

Fabry-Perot-interferometer imaging system for thermospheric temperature and wind measurements. Applied Optics 19(13): 2206-2209, 1980

Upper thermospheric neutral wind and temperature measurements from an extended spatial field. Annales Geophysicae 26(9): 2649-2655, 2008

Partial solar eclipse effects on temperature and wind in an equatorial atmosphere. Journal of Geophysical Research 79(33): 5052-5054, 1974

Dual Fabry-Perot spectrometer measurements of daytime thermospheric temperature and wind velocity: data analysis procedures. Applied Optics 22(5): 726-732, 1983

Equatorial Zonal Wind in the Middle Atmosphere Derived from Geopotential Height and Temperature Data. Journal of the Atmospheric Sciences 46(6): 860-866, 1989

Testing the thermospheric neutral wind suppression mechanism for day-to-day variability of equatorial spread F. Journal of Geophysical Research 106(A3): 3655-3663, 2001

Nonmigrating tidal signals in the upper thermospheric zonal wind at equatorial latitudes as observed by Champ. Annales Geophysicae 27(7): 2643-2652, 2009

Thermospheric Meridional Wind Control on Equatorial Scintillations and the Role of the EveningF-Region Height Rise,E. Surveys in Geophysics 31(5): 509-530, 2010

Thermospheric wind effects on the distribution of helium and argon in the Earth's upper atmosphere. Journal of Geophysical Research 78(16): 2977-2991, 1973

Applications of AMSR-E measurements for tropical cyclone predictions Part I: Retrieval of Sea Surface Temperature and Wind speed. Advances in Atmospheric Sciences 25(2): 227-245, 2008

New results on equatorial thermospheric winds and the midnight temperature maximum. Annales Geophysicae 26(3): 447-466, 2008

Comparisons between Hygroscopic Measurements and UNIFAC Model Predictions for Dicarboxylic Organic Aerosol Mixtures. Advances in Meteorology 2013: 1-9, 2013

Measurements of upper atmosphere wind and temperature from meteorological rocket experiments during winter 1979. Advances in Space Research 2(10): 177-180, 1982