Cosmic Temperature Research Articles

Thermodynamics of warm axionic Abelian gauge inflation

Inflationary spectral index from the Langevin equation is calculated under the frame of warm inflationary scenario with inflaton interacting with U(1) gauge fields through the Chern–Simons coupling ∝ ϕ F μ ν F ∼ μ ν / f . Under the strong dissipative condition, the spectral index is calculated in terms of the ratio of Hubble parameter to temperature H/T. Then relation between H/T and other cosmic parameters is analytically expressed, based on which a spectral index related to the Chern–Simons coupling strength is further obtained. Numerical results show that cosmic temperature T closes to a constant during inflation and decreases after inflation without a reheating process. Meanwhile, the ratio H/T tends to a constant if the gauged coupling constant is less than a threshold. This phenomenon shows that cosmic temperature may be an important physical parameter with a special value and adiabatic approximation still holds. We obtain the estimate H/T ≤ 0.3377 during inflation from Planck data and other constraint conditions.

Concepts and Results of a Practical Model of Quantum Cosmology

We have proposed new concepts and results pertaining to a very simple and practical model of quantum cosmology based on light speed expanding black hole universe having no dark matter and no dark energy. Big bang concept can be replaced with Plank scale. Cosmic temperature and expansion rate can be related with scaled Hawking’s Black hole temperature formula. Starting from cosmic center to cosmic boundary, a decreasing trend of galactic acceleration can be understood with continuous light speed expansion at cosmic boundary. Issue of ‘causal disconnection of galaxies at large scale distances’ can be eliminated by cosmic black hole physical concepts. Dark matter concept can be eliminated with ‘super gravity of galactic baryonic mass caused by weak interaction’. Cosmic inflation and dark energy concepts can be eliminated with ‘light speed expansion’. To fit the estimated light travel distances and to eliminate the dark energy, cosmic red shift can be redefined

Weak Interaction Dependent Super Gravity of Galactic Baryon Mass

Considering our light speed growing Planck scale universe, it seems possible to develop a practical model of Hubble-Hawking Universe by using which cosmic temperature and Hubble parameter can be correlated accurately. Without considering galactic dark matter, galactic flat rotation speeds can be addressed with ‘super gravity’ of galactic baryonic mass. In this context, (180 to 200) million solar masses can be considered as a characteristic upper mass limit of ordinary gravity. Considering the proposed current upper mass limit of ordinary gravity as a characteristic weak interaction mass unit, hypothecated galactic dark matter can be quantified. Clearly speaking, weak interaction boosts the gravity of galaxies in proportion to their virtual dark mass as (galactic baryonic mass)3/2 / (200 million solar masses)1/2. Based on cosmic recombination temperature and baryon acoustic bubble radius, upper mass limit of gravity can also be fitted. With further study, dark matter existence and physical properties can be explored.

Estimation of Random Error Statistics in High-Resolution Radiosondes, ERA-Interim, and COSMIC Radio Occultation Soundings in the Northeast Pacific Ocean during the MAGIC Campaign

Abstract Random errors (uncertainties) in COSMIC radio occultation (RO) soundings, ERA-Interim (ERAi) reanalyses, and high-resolution radiosondes (RS) are estimated in the northeast Pacific Ocean during the MAGIC campaign in 2012 and 2013 using the three-cornered hat method. Estimated refractivity and bending angle errors peak at ∼2 km, and have a secondary peak at ∼15 km. They are related to vertical and horizontal gradients of temperature and water vapor and associated atmospheric variability at these two levels. MAGIC RS refractivity and bending angles obtained from forward models have the largest uncertainties, followed by COSMIC RO soundings. ERAi has the smallest uncertainties. The large RS uncertainties can be primarily attributed to representativeness errors (differences). Differences in space and time of the RO and model datasets from the RS observations, error correlations among datasets, and the small sample size are other possible reasons contributing to these differences of estimated error statistics. RO temperature and humidity are retrieved from refractivity using a one-dimensional variational (1D-Var) method from the COSMIC Data Analysis and Archive Center (CDAAC). The estimated errors for COSMIC temperature are comparable to those of the MAGIC RS except near 1 km, where they are much higher. The estimated errors for COSMIC specific humidity are similar to the MAGIC specific humidity errors below ∼5 km and much smaller above this level. Estimates of COSMIC random errors based on ERAi, JRA-55, and MERRA-2 reanalyses in the same region, as well as comparison with estimates from other studies, support the reliability of our estimates.

Wormholes in a viscous universe

We study the static and spherically symmetric wormhole spacetime configurations at present time in a viscous universe. Considering three classes of viscous models, i.e., bulk viscosity as a function of Hubble constant $H_0$, present cosmic temperature $T_0$ and dark energy density $\rho_0$, respectively, we obtain several wormhole solutions. Through the analysis for the anisotropic solutions, we conclude that, to some extent, these three classes of viscous models have very high degeneracy with each other, and deviate slightly from the ideal fluid consequence. Subsequently, without the loss of generality, to investigate the traversabilities, energy conditions and stability for the wormhole solution, we study the wormhole solution of the constant redshift function of the viscous $\omega$CDM model with a constant bulk viscosity coefficient. We obtain the following conclusions: the value of traversal velocity decreases for decreasing bulk viscosity, and the traversal velocity for a traveler depends on not only the wormhole geometry but also the effects of cosmological background evolution; the null energy condition will be violated more clearly when the bulk viscosity or the cosmic expansion velocity decreases; for the case of a positive surface energy density, the range of the junction radius decreases and the values of the parameter $\lambda$ are further restricted when the throat radius of the wormhole $r_0/M$ increases, bulk viscosity coefficient $\zeta_0$ decreases and present-day Hubble parameter $H_0$ decreases, respectively; for the case of a negative surface energy density, by increasing $r_0/M$, decreasing $\zeta_0$ and increasing $H_0$, the values of the parameter $\lambda$ are less restricted, one may conclude that the total stability region increases, and the range of the junction radius increases, increases and decreases, respectively. \end{abstract}

Cosmic evolution of lepton flavor charges

In the early Universe above the weak scale, both baryon $B$ and lepton $L$ numbers are violated by nonperturabive effects in the Standard Model while $B\ensuremath{-}L$ remains conserved. Introducing new physics which violates perturbatively $L$ and/or $B$, one can generate dynamically a nonzero $B\ensuremath{-}L$ charge and hence a nonzero $B$ charge. In this work, we focus on the former scenario, which is also known as leptogenesis. We show how to describe the evolutions of lepton flavor charges taking into account the complete Standard Model lepton flavor and spectator effects in a unified and lepton flavor basis--independent way. The recipe we develop can be applied to any leptogenesis model with arbitrary number of new scalars carrying nonzero hypercharges and is valid for cosmic temperature ranging from ${10}^{15}\text{ }\text{ }\mathrm{GeV}$ down to the weak scale. We demonstrate that in order to describe the physics in a basis-independent manner and to include lepton flavor effect consistently it is necessary to describe both left-handed and right-handed lepton charges in terms of density matrices. This is a crucial point since physics should be basis independent. As examples, we apply the formalism to type-I and type-II leptogenesis models where in the latter case a flavor-covariant formalism is indispensable.

A revisited study of the cosmic matter recombination in expanding universes

It is generally believed by cosmologists that the universe back in its past was hot, and matter was completely ionized and in thermal equilibrium, while in the present era matter, due to a strong cosmic temperature decrease, has recombined to neutral atoms. As we argue here, contrary to general assumption, a non-equilibrium state predominates at this phase of the recombination and the usually used Saha-Eggert theorem hence is inapplicable. In a preceding paper, we had already derived a specific kinetic transport equation which describes the distribution function of cosmic baryon gas (i.e. hydrogen atoms) just after cosmic matter recombination. We could solve the relevant kinetic transport equation for that period and found the gas distribution function f(v,t) as function of the particle velocity v and of the cosmic time . However here, in this paper, we shall go one important step further back in the cosmic evolution and do study in more detail, how in successive steps the recombination of cosmic electrons and protons did actually occur. We clearly show that matter and radiation in the phase of cosmic recombination is not anymore in a thermodynamic equilibrium state, since matter and radiation do cool off in different forms, and a thermodynamic situation predominates where protons, electrons and photons have different temperatures, and collision-based energy transfer processes operate between them. Hence cosmic recombination, thought to have occured about 400000 years after the Big-Bang, does not take place starting from a thermodynamic equilibrium state as generally presumed, and hence the standard Saha-Eggert assumptions and predictions on the ionization degree of cosmic matter as function of the system temperature can not be used. We follow in detail the processional track how the cosmic radiation and the cosmic matter behave in this critical non-equilibrium phase and show that the recombination of cosmic matter actually occurs, though there is a yet unrespected tendency that freely moving particles in an expanding universe become heated by the action of the differential Hubble drifts which, in a first glance, should impede their recombination.

Baryogenesis in the standard model and its supersymmetric extension

In this work, we classify all the effective $U(1)$ symmetries and their associated Noether charges in the Standard Model (SM) and its minimal supersymmetric extension (MSSM) from the highest scale after inflation down to the weak scale. We then demonstrate that the discovery of the violation of baryon minus lepton number ($B-L$) which pinpoints to its violation in primordial Universe at any cosmic temperature above $30$ TeV will open up a new window of baryogenesis in these effective charges above this scale. While the fast SM baryon number violation in the early Universe could be the first piece to solve the puzzle of cosmic baryon asymmetry, $(B-L)$ violation could be the second important piece. In the background of expanding Universe, there is ample opportunity for out-of-equilibrium processes to generate an asymmetry in the numerous effective charges in the SM or the MSSM, making a baryon asymmetric Universe almost unavoidable. Finally we provide examples in the SM and the MSSM where baryogenesis can proceed through out-of-equilibrium dynamics without explicitly breaking baryon nor lepton number.

Migrating and non-migrating tides observed in the stratosphere from FORMOSAT-3/COSMIC temperature retrievals

Abstract. Formosa Satellite-3 and Constellation Observing System for Meteorology, Ionosphere and Climate (FORMOSAT-3/COSMIC) temperature data during October 2009–December 2010 are analysed for tides in the middle atmosphere from ∼10 to 50 km. COSMIC is a set of six micro-satellites in near-Sun-synchronous orbits with 30∘ orbital separations that provides good phase space sampling of tides. Short-term tidal variability is deduced by considering ±10 d data together. The migrating diurnal (DW1) tide is found to peak over the Equator at 30 km. It maximises and slightly shifts poleward during winters. Over middle and high latitudes, DW1 and the non-migrating diurnal tides with wavenumber 0 (DS0) and wavenumber 2 (DW2) are intermittent in nature. Numerical experiments in the current study show that these could be a result of aliasing as they are found to occur at times of a steep rise or fall in the mean temperature, particularly during the sudden stratospheric warming (SSW) of 2010. Further, the stationary planetary wave component of wavenumber 1 (SPW1) is found to be of very large amplitudes in the Northern Hemisphere, reaching 18 K at 30 km over 65∘ N. By using data from COSMIC over shorter durations, it is shown that aliasing between stationary planetary wave and non-migrating tides is reduced and thus results in the large amplitudes of the former. This study clearly indicates that non-linear interactions are not a very important source for the generation of non-migrating tides in the middle- and high-latitude winter stratosphere. There is also a modulation of SPW1 by a ∼60 d oscillation in the high latitudes, which was not seen earlier.

Atmospheric Sounding from Fengyun-3C GPS Radio Occultation Observations: First Results and Validation

Carrying global positioning system (GPS) radio occultation (RO) receiver, Chinese meteorological satellite Fengyun-3C (FY-3C) was launched on September 23, 2013, which provides new observation data for observations and studies of weather and climate change. In this paper, the results of FY-3C GPS RO atmospheric sounding are presented for the first time, including high-order ionospheric correction, atmospheric parameters estimation, and evaluation by COSMIC and radiosonde observations as well as applications in estimating gravity wave activities. It is found that the effect of the ionospheric correction residual on the phase delay is below 20 mm, which has minimal impact on bending angle estimation and generates differences of about 1 K in the average temperature profile. The difference between FY-3C and COSMIC temperatures at all heights is within 1°C, and the tropopause temperature and height have a good consistency. Deviations from Radiosonde measurements are within 2°C, and the tropopause temperature and height results also have a strong consistency. Furthermore, global gravity wave potential energy is estimated from FY-3C GPS RO, exhibiting similar behavior to results derived from COSMIC radio occultation measurements. The mean value of the gravity wave potential energy near the equator is 10 J/kg and decreases toward the two poles while in the northern hemisphere, it is stronger than that in the southern hemisphere.

An Outline Picture of a Growing and Rotating Planck Universe with Emerging Dark Foam

With reference to Planck scale, Mach’s relation, increasing support for large scale cosmic anisotropy and preferred directions and by introducing two new parameters Gamma and Beta, right from the beginning of Planck scale, we make an attempt to estimate ordinary matter density ratio, dark matter density ratio, mass, radius, temperature, age and expansion velocity (from and about the bay universe in all directions). We would like suggest that, from the beginning of Planck scale, 1) Dark matter can be considered as a kind of cosmic foam responsible for formation of galaxies. 2) Cosmic angular velocity is directly proportional to squared cosmic temperature. 3) Cosmic expansion velocity increases with decreasing total matter density ratio. 4) There is no need to consider dark energy for understanding cosmic acceleration.

The vertical wave number spectra of potential energy density in the stratosphere deduced from the COSMIC satellite observation

The present study investigates the global vertical wave number spectra of potential energy density in the stratosphere by utilizing the COSMIC temperature data in the period January 2007 to February 2014. The statistical analysis shows that the spectral amplitude (defined as the maximum spectral energy density) varies from 0.1 × 104 m2 s−2 (cycle/m)−1 to 3.2 × 104 m2 s−2 (cycle/m)−1, generally smaller than the theoretical saturated spectral amplitude, with remarkable temporal and spatial variations. Due to the latitudinal and seasonal variations of the background winds and wave sources, the amplitude exhibits obvious quasi‐biennial, annual and semi‐annual cycles at low latitudes, and the annual cycle at middle and high latitudes. The spectral slope, ranging from −1.6 to −3.0, is systematically less negative than the canonical value of −3, and exhibits a quasi‐biennial cycle at low latitudes, annual cycle at middle and high latitudes, and semi‐annual cycle at boreal high latitudes. Different from the amplitude, the slope shows weaker temporal and latitudinal variations, strongly indicating a more universal feature of the slope, which mainly results from the wave propagation process (such as the wave–wave or wave–background flow interactions) rather than the wave source characteristics. Furthermore, we statistically study the longitudinal variation of the spectral parameters. The spectral amplitude at different latitudes shows an obvious and distinctive longitudinal distribution, which is attributed to the latitude‐dependent jet and front mechanisms and/or orography. However, the slope has no evident longitudinal distribution except over around 120°W, 67°W and 85°E. This may be accounted for by the fact that orography‐excited gravity waves are easily influenced by the background winds due to their low frequencies. Interestingly, the amplitude and slope have negative correlation at most latitudes. Larger spectral amplitudes could mean that the gravity wave spectrum is more strongly saturated, resulting in a spectral slope closer to the theoretical value of −3.

Photon Gas Is the Medium of Electromagnetic Waves

The aim of this paper is to find the carrier or medium of electromagnetic waves that has been searched for many years. The thermal radiation is composed of the shot noise and the wave noise, so the Planck formula can be separated mathematically into two parts. Assume every photon has the same proper magnetic moment and an equal rest mass which has been estimated from the cosmic background temperature in space where the photon gas is at an open state of thermal equilibrium. The magnetic-electric dynamic equation is established that means magnetic curl caused electric change, and the electric-magnetic dynamic equation is established that means electric curl caused magnetic change. After the wave equation is caught, it is clear that the photon gas is the medium of electromagnetic waves in vacuum.

Temperature Scaling in Flat Space Cosmology in Comparison to Standard Cosmology

Flat Space Cosmology (FSC) is a mathematical model of universal expansion which has proven to be remarkably accurate in comparison to observations. Temperature scaling is redefined in this paper in terms of a new “Universal Temperature” Tu scale according to Tu = T 2, where T 2 is in K2. This rescaling puts FSC cosmic temperature, time, total matter mass, and Hubble radius on the same scale, covering roughly 60.63 logs of 10 from the Planck scale to the present scale. This paper focuses on the relatively subtle temperature curve differences between the FSC model and standard cosmology. These changes become more pronounced in the early universe. Recent observational studies of the early universe, particularly with respect to the “cosmic dawn” epoch, the first stars and first galaxies, have surprised standard model proponents as to how soon these events have occurred following the Big Bang. This paper suggests that, because the FSC model temperature/time curve is lower at each stage of cosmic time, FSC may actually be a better fit for the timing of these events.

Climatology and interannual variability of dynamic variables in multiple reanalyses evaluated by the SPARC Reanalysis Intercomparison Project (S-RIP)

Abstract. Two of the most basic parameters generated from a reanalysis are temperature and winds. Temperatures in the reanalyses are derived from conventional (surface and balloon), aircraft, and satellite observations. Winds are observed by conventional systems, cloud tracked, and derived from height fields, which are in turn derived from the vertical temperature structure. In this paper we evaluate as part of the SPARC Reanalysis Intercomparison Project (S-RIP) the temperature and wind structure of all the recent and past reanalyses. This evaluation is mainly among the reanalyses themselves, but comparisons against independent observations, such as HIRDLS and COSMIC temperatures, are also presented. This evaluation uses monthly mean and 2.5° zonal mean data sets and spans the satellite era from 1979–2014. There is very good agreement in temperature seasonally and latitudinally among the more recent reanalyses (CFSR, MERRA, ERA-Interim, JRA-55, and MERRA-2) between the surface and 10 hPa. At lower pressures there is increased variance among these reanalyses that changes with season and latitude. This variance also changes during the time span of these reanalyses with greater variance during the TOVS period (1979–1998) and less variance afterward in the ATOVS period (1999–2014). There is a distinct change in the temperature structure in the middle and upper stratosphere during this transition from TOVS to ATOVS systems. Zonal winds are in greater agreement than temperatures and this agreement extends to lower pressures than the temperatures. Older reanalyses (NCEP/NCAR, NCEP/DOE, ERA-40, JRA-25) have larger temperature and zonal wind disagreement from the more recent reanalyses. All reanalyses to date have issues analysing the quasi-biennial oscillation (QBO) winds. Comparisons with Singapore QBO winds show disagreement in the amplitude of the westerly and easterly anomalies. The disagreement with Singapore winds improves with the transition from TOVS to ATOVS observations. Temperature bias characteristics determined via comparisons with a reanalysis ensemble mean (MERRA, ERA-Interim, JRA-55) are similarly observed when compared with Aura HIRDLS and Aura MLS observations. There is good agreement among the NOAA TLS, SSU1, and SSU2 Climate Data Records and layer mean temperatures from the more recent reanalyses. Caution is advised for using reanalysis temperatures for trend detection and anomalies from a long climatology period as the quality and character of reanalyses may have changed over time.

Unusual enhancement in tropospheric and surface ozone due to orography induced gravity waves

In this study, we investigate the causative processes responsible for the observed enhancement in the tropospheric and surface ozone during December 09–11, 2008 orography induced gravity wave event over Himalayan region. The analysis is done using surface ozone measurements and satellite datasets from Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit-A (AIRS/AMSU-A), COSMIC, TES and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO). Observations depict a two fold increase in surface and tropospheric ozone during the event as compared to normal days in both AIRS and TES ozone measurements. COSMIC temperature perturbations show generation of shorter vertical wavelengths efficient for the sub-tropical tropopause folding due to orography induced gravity waves. Moreover, the intense tropopause folding as evidenced by upward-downward vertical velocities couplet could trigger the intrusion of stratospheric ozone rich air into upper tropospheric ozone poor air as also confirmed by high values of potential vorticity during the observational period. Hence, present study reemphasizes the importance of wave induced atmospheric dynamics on atmospheric constituents' especially tropospheric ozone over Himalayan region.

Semiclassical treatment of a k-essence effect on cosmic temperature

A phenomenological model with quantum fluctuations of matter fields is described for the Cosmic Microwave Background (CMB) radiation evolution in the presence of dark energy in the form of a k-essence scalar field ϕ(t). Our model is realized through a time-dependent oscillator Lagrangian. Here ϕ couples to the scale factor a(t). Themodel gives: (a) the observed variation of a with time and (b) the observed value of the epoch when the universe passed over from decelerated to accelerated phase. These two features have been matched with graphical transcriptions of SNe Ia data. Further, the evolution is sensitive to the presence of an inhomogeneity. Its sensitivity increases as one goes further into the past. The value of the inhomogeneity parameter determines the transition epoch from decelerated to accelerated phase. A positive value of the inhomogeneity parameter leads an earlier transition, and its negative value to a later one. A slightly negative value of the inhomogeneity parameter gives a better agreement with the observed value for the transition time. The formalism also accommodates dark matter in the form of non-relativistic dust without any change in the above scenarios.

Variations of Kelvin waves around the TTL region during the stratospheric sudden warming events in the Northern Hemisphere winter

Abstract. Spatial and temporal variabilities of Kelvin waves during stratospheric sudden warming (SSW) events are investigated by the ERA-Interim reanalysis data, and the results are validated by the COSMIC temperature data. A case study on an exceptionally large SSW event in 2009, and a composite analysis comprising 18 events from 1980 to 2013 are presented. During SSW events, the average temperature increases by 20 K in the polar stratosphere, while the temperature in the tropical stratosphere decreases by about 4 K. Kelvin wave with wave numbers 1 and 2, and periods 10–20 days, clearly appear around the tropical tropopause layer (TTL) during SSWs. The Kelvin wave activity shows obvious coupling with the convection localized in the India Ocean and western Pacific (Indo-Pacific) region. Detailed analysis suggests that the enhanced meridional circulation driven by the extratropical planetary wave forcing during SSW events leads to tropical upwelling, which further produces temperature decrease in the tropical stratosphere. The tropical upwelling and cooling consequently result in enhancement of convection in the equatorial region, which excites the strong Kelvin wave activity. In addition, we investigated the Kelvin wave acceleration to the eastward zonal wind anomalies in the equatorial stratosphere during SSW events. The composite analysis shows that the proportion of Kelvin wave contribution ranges from 5 to 35 % during SSWs, much larger than in the non-SSW mid-winters (less than 5 % in the stratosphere). However, the Kelvin wave alone is insufficient to drive the equatorial eastward zonal wind anomalies during the SSW events, which suggests that the effects of other types of equatorial waves may not be neglected.

Applications of light speed expansion and gravitational self-energy density in black hole cosmology

From the beginning of Planck scale to the scale of the current Hubble radius: 1) Considering the relation, subjects of black holes and cosmology, both can be integrated into evolving black hole cosmology and cosmic horizon problem can be relinquished. 2) Considering ‘continuous light speed expansion’ of the cosmic black hole horizon, attributed results of cosmic inflation can be re-addressed completely. If ‘nature’ of the universe is to expand with light speed, then there is no need to think about the existence of currently believed ‘Lambda term’. In addition, ‘light speed expanding cosmic space’ can be called as ‘flat space’. 3) Considering the ratio of gravitational self-energy density and thermal energy density to be  (where  is the Planck scale temperature, and is cosmic temperature at any time). Quantum gravity can be implemented in low energy scale current cosmological observations. Considering the above concepts, currently believed dark matter energy density and visible matter energy density both can be accurately fitted with the ratio of current gravitational self-energy density and current thermal energy density. To proceed further, the authors would like to highlight the following three points: 1) Deep-space red shift non-linearity can be expected to be connected with cosmological gravitational and relativistic effects and cannot be considered as a major criterion of cosmic evolution. 2) Until one finds solid applications of super luminal speeds and super luminal expansions in other areas of physics like astrophysics and nuclear astrophysics, currently believed ‘cosmic inflation’ cannot be considered as a real physical model and alternative proposals of inflation can be given a chance in exploring the evolving history of the universe. 3) Implementing Planck scale in current paradigm of cosmological observations and standard cosmology is very challenging and is inevitable.

The southern stratospheric gravity wave hot spot: individual waves and their momentum fluxes measured by COSMIC GPS-RO

Abstract. Nearly all general circulation models significantly fail to reproduce the observed behaviour of the southern wintertime polar vortex. It has been suggested that these biases result from an underestimation of gravity wave drag on the atmosphere at latitudes near 60° S, especially around the "hot spot" of intense gravity wave fluxes above the mountainous Southern Andes and Antarctic peninsula. Here, we use Global Positioning System radio occultation (GPS-RO) data from the COSMIC satellite constellation to determine the properties of gravity waves in the hot spot and beyond. We show considerable southward propagation to latitudes near 60° S of waves apparently generated over the southern Andes. We propose that this propagation may account for much of the wave drag missing from the models. Furthermore, there is a long leeward region of increased gravity wave energy that sweeps eastwards from the mountains over the Southern Ocean. Despite its striking nature, the source of this region has historically proved difficult to determine. Our observations suggest that this region includes both waves generated locally and orographic waves advected downwind from the hot spot. We describe and use a new wavelet-based analysis technique for the quantitative identification of individual waves from COSMIC temperature profiles. This analysis reveals different geographical regimes of wave amplitude and short-timescale variability in the wave field over the Southern Ocean. Finally, we use the increased numbers of closely spaced pairs of profiles from the deployment phase of the COSMIC constellation in 2006 to make estimates of gravity wave horizontal wavelengths. We show that, given sufficient observations, GPS-RO can produce physically reasonable estimates of stratospheric gravity wave momentum flux in the hot spot that are consistent with measurements made by other techniques. We discuss our results in the context of previous satellite and modelling studies and explain how they advance our understanding of the nature and origins of waves in the southern stratosphere.