Lidar measurements of stratosphere‐mesosphere thermal structure at a low latitude: Comparison with satellite data and models

Abstract

[1] Making use of 240 nights of Rayleigh lidar data collected over March 1998 to July 2001, we present the general characteristics of low-latitude middle atmospheric temperature structure over Gadanki (13.5°N, 79.2°E). The height-monthly mean temperature contour plot shows two distinct maxima in the stratopause region ($45-55 km), occurring over February-March and September-October, a seasonal dependence quite different from that reported for midlatitudes and high latitudes. The statistical distributions of stratopause and its temperature show the most probable values to be 47-48 km and 262-264 K, respectively. A comparison with the satellite (UARS Halogen Occultation Experiment) data shows a fairly good agreement, but for the mesospheric inversion region of 70-80 km, where the lidar measurements are about 5-10 K warmer than those of the satellite. A comparison with the models, CIRA-86 and Mass Spectrometer Incoherent Scatter Extended-1990 (MSISE-90), showed that the agreement with differences less than 3 K is the best for CIRA-86 over $40-55 km and MSISE-90 over 55-65 km. Below 40 km, both models overestimate by 3-9 K, with deviations somewhat larger for MSISE-90. For 70-80 km both models deviate significantly, with differences exceeding 10 K, particularly during equinoctial periods when the mesospheric inversion occurs most frequently.

Observation of semiannual and annual oscillation in equatorial middle atmospheric long term temperature pattern

“…It utilizes Nd:YAG pulsed laser transmitter with two receiving telescopes (Rayleigh and Mie), data acquisition and processing subsystems. The photon counts received by the Rayleigh telescope are used to derive temperature profiles using the almost similar algorithm of Hauchecorne and Chanin (1980) with time resolution of 250 s and height resolution of 300 m. Details of the data analysis and the system configuration is given elsewhere (Siva Kumar et al, 2003). Most recent observation from the same site, using comparative lidar and SABER temperature, Kishore (hereafter referred as KK08) concluded that the Gadanki lidar is very reliable for accurate temperature measurements in the range ∼35-80 km with an accuracy 0.5-1.5 K in the stratosphere and 2-3 K in the mesosphere.…”

Global temperature estimates in the troposphere and stratosphere: a validation study of COSMIC/FORMOSAT-3 measurements

“…Hertzog et al, 2003;Pommerau et al, 2002;Knudsen et al, 2002). Knowledge of the upper tropospheric and lower stratospheric temperatures is important for understanding the structure and dynamics of Correspondence to: P. Kishore (kishore1818@gmail.com) the region, and is related to the issues connected to global climate change and the stratosphere-troposphere exchanges (Holton et al, 1995;Baray et al, 1998;Burris et al, 1998;Steinbrecht et al, 1998). A wide variety of observational techniques have been used to measure temperature in the troposphere and lower stratosphere and their variations in time and space.…”

“…Dewan et al, 1984;Hamilton, 1991;Eckermann et al, 1995), and lidar studies (e.g. Wilson et al, 1991;Hauchecorne and Chanin, 1980;Chanin and Hauchecorne, 1991;Whiteway and Carswell, 1994;LeBlanc et al, 1998;Sivakumar et al, 2003), etc. Most of these observations are mainly over land areas of the Northern Hemisphere (NH) and the period of observations has been limited.…”

Influence of gravity waves and tides on mesospheric temperature inversion layers: simultaneous Rayleigh lidar and MF radar observations

“…The Rayleigh receiver employs a Newtonian telescope of diameter 750 mm, detected by photo multiplier and counted sequentially into successive 300-m range bins. More details of this instrument and method of analysis can be had from Siva Kumar et al (2003). The four minute averaged photon count profiles were averaged for 30 min and temperature and its standard error are determined using the method given by Hauchecorne and Chanin (1980).…”