Martin G. Mlynczak

• Ph.D., Atmospheric Science
• Senior Researcher at National Aeronautics and Space Administration

The magnetosphere‐ionosphere‐thermosphere system is externally driven by the energy input from the solar wind. A part of the solar wind energy deposited in the magnetosphere during geomagnetically active periods dissipates into the thermosphere. Previous studies have reported temperature perturbations in the lower thermosphere during geomagnetic st...

Polar mesospheric clouds (PMC), or noctilucent clouds, can be observed over high latitudes with the naked eye from the ground or from space near the summer solstice. PMC are considered a direct and sensitive indicator of climate change and have been reported to appear more frequently in recent decades. How PMC will change in the future under the in...

Interesting observational evidence of interaction between a mesospheric bore and a mesospheric front is found in O(1S) 557.7 nm airglow images over the western Himalayan region on 25 April 2022. The event is unique as it is the first report of a mesospheric bore interacting with a typical mesospheric front. The vertical profiles of temperature and...

Plain Language Summary Instruments on Earth orbiting satellites offer the opportunity to detect long‐term changes in atmospheric temperature. Many factors may affect the ability to identify actual long‐term changes in the temperature and to distinguish these from changes in the instrument or from unintended changes in the algorithm that produces th...

The behaviors of the nitric oxide (NO) cooling in the lower thermosphere during the 14 December 2020 solar eclipse are studied using Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) measurements and WACCM‐X simulations. We found that NO cooling rate decreases during the solar eclipse in both SABER measurements and WACCM‐X simu...

The Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) was launched aboard NASA’s Ionospheric Connection (ICON) Explorer satellite in October 2019 to measure winds and temperatures on the limb in the upper mesosphere and lower thermosphere (MLT). Temperatures are observed using the molecular oxygen atmospheric band n...

We examine the thermal structure of the mesosphere and lower thermosphere (MLT) using observations from 2002 through 2021 from the SABER instrument on the NASA TIMED satellite. These observations show that the MLT has significantly cooled and contracted between the years 2002 and 2019 (the year of the most recent solar minimum) due to a combination...

This work presents a method for estimating the migrating diurnal tide (DW1) component of mesospheric H2O from observations of the temperature tide and zonal‐mean H2O made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument. This work first shows that a 2D least‐squares fit on SABER H2O yields an erroneous DW1 du...

Water vapor in the middle atmosphere plays an essential role in global warming, ozone depletion, and the formation of polar stratospheric and mesospheric clouds. We show that tropical middle atmospheric water vapor simulated with the specified‐dynamics version of the Whole Atmosphere Community Climate Model (SD‐WACCM) is consistent with changes obs...

In the mesosphere and lower thermosphere (MLT) region, residual circulations driven by gravity wave breaking and dissipation significantly impact constituent distribution and the height and temperature of the mesopause. The distribution of CO2 can be used as a proxy for the residual circulations. Sounding of the Atmosphere using Broadband Emission...

Atomic oxygen (O) in the mesosphere and lower thermosphere (MLT) results from a balance between production via photo‐dissociation in the lower thermosphere and chemical loss by recombination in the upper mesosphere. The transport of O downward from the lower thermosphere into the mesosphere is preferentially driven by the eddy diffusion process tha...

Gravity waves play a significant role in driving the semiannual oscillation (SAO) of the zonal wind in the tropics. However, detailed knowledge of this forcing is missing, and direct estimates from global observations of gravity waves are sparse. For the period 2002–2018, we investigate the SAO in four different reanalyses: ERA-Interim, JRA-55, ERA...

An intriguing and rare gravity wave event was recorded on the night of 25 April 2017 using a multiwavelength all-sky airglow imager over northern Germany. The airglow imaging observations at multiple altitudes in the mesosphere and lower thermosphere region reveal that a prominent upward-propagating wave structure appeared in O(1S) and O2 airglow i...

Recently, citizen scientist photographs led to the discovery of a new auroral form called “the dune aurora” which exhibits parallel stripes of brighter emission in the green diffuse aurora at about 100 km altitude. This discovery raised several questions, such as (i) whether the dunes are associated with particle precipitation, (ii) whether their s...

Gravity waves play a significant role in driving the semiannual oscillation (SAO) of the zonal wind in the tropics. However, detailed knowledge of this forcing is missing, and direct estimates from global observations of gravity waves are sparse. For the period 2002–2018, we investigate the SAO in four different reanalyses: ERA-Interim, JRA-55, ERA...

Abstract NRLMSIS® 2.0 is an empirical atmospheric model that extends from the ground to the exobase and describes the average observed behavior of temperature, eight species densities, and mass density via a parametric analytic formulation. The model inputs are location, day of year, time of day, solar activity, and geomagnetic activity. NRLMSIS 2....

Ongoing climate change in Earth’s middle and upper atmosphere will affect the rapidly expanding space and telecommunications sectors. Maintaining observations of this region is more crucial than ever.

The spectroscopy of the  = 1   = 0 fundamental vibration-rotation band of nitric oxide (NO) in Earths‟ atmosphere is examined in depth in order to further assess the long-running dataset of infrared radiative cooling rates in the thermosphere from the SABER instrument on the NASA TIMED satellite. The fundamental band at 5.3 m is shown to be alm...

An undular mesospheric bore event has been recorded over the western Himalayan region in O(¹S) 557.7 nm airglow images on a clear and moonless night of 02 October 2018 using a multi-wavelength all-sky imager at Hanle, Leh Ladakh, India (32.77°N, 79.97°E). The bore has a prominent leading dark front followed by trailing waves and it propagates with...

Airglow spectrometers, as they are operated within the Network for the Detection of Mesospheric Change (NDMC; https://ndmc.dlr.de, last access: 1 November 2020), for example, allow the derivation of rotational temperatures which are equivalent to the kinetic temperature, local thermodynamic equilibrium provided. Temperature variations at the height...

This paper characterizes the impacts of sudden stratospheric warmings (SSWs) and mesospheric coolings (MCs) on the light species distribution (i.e., helium [He], and atomic hydrogen [H]) of the thermosphere using a combined data‐modeling approach. Performing a set of numerical experiments with a general circulation model whose middle atmospheric dy...

Two upcoming missions are scheduled to provide novel spaceborne observations of upwelling far-infrared spectra. In this study, the accuracy of ice cloud property retrievals using spaceborne middle-to-far-infrared (MIR-FIR) measurements is examined toward a better understanding of retrieval biases and uncertainties. Theoretical sensitivity studies d...

The exchange of energy between the lower atmosphere and the ionosphere thermosphere system is not well understood. One of the parameters that is important in the lower thermosphere is atomic oxygen. It has recently been observed that atomic oxygen is higher in summer at ∼95 km. In this study, we investigate the sensitivity of the upper thermosphere...

The outgoing longwave radiation (OLR) emitted to space is a fundamental component of the Earth’s energy budget. There are numerous, entangled physical processes that contribute to OLR and that are responsible for driving, and responding to, climate change. Spectrally resolved observations can disentangle these processes, but technical limitations h...

Abstract. Airglow spectrometers as they are operated within the Network for the Detection of Mesospheric Change (NDMC, https://ndmc.dlr.de , for example, allow the derivation of rotational temperatures which are equivalent to the kinetic temperature, local thermodynamic equilibrium provided. Temperature variations at the height of the airglow layer...

The search for life in the Universe is a fundamental problem of astrobiology and modern science. The current progress in the detection of terrestrial-type exoplanets has opened a new avenue in the characterization of exoplanetary atmospheres and in the search for biosignatures of life with the upcoming ground-based and space missions. To specify th...

This work reports the analysis of the local‐time variations of daytime CO2 in the Upper Mesosphere and Lower Thermosphere region as observed by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite. Results show that daytime SABER CO2 in...

The SABER instrument on the NASA TIMED satellite continues to provide a long-term record of Earth’s stratosphere, mesosphere, and lower thermosphere. The SABER data are being used to examine long-term changes and trends in temperature, water vapor, and carbon dioxide. A tacit, central assumption of these analyses is that the SABER instrument radiom...

There has been much work on the value of learning about climate and the value of information regarding the climatic system. The present research moves beyond an abstract hypothesis about future learning and considers concrete Earth Observing Systems that could enhance knowledge of the climatic system and better inform decision makers. This study sh...

A new model of exospheric temperatures has been developed, with the objective of predicting global values with greater spatial and temporal accuracy. From these temperatures, the neutral densities in the thermosphere can be calculated, through use of the Naval Research Laboratory Mass Spectrometer and Incoherent Scatter radar Extended (NRLMSISE‐00)...

Analyzing Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) observations from 2003 to 2018, the interannual variability of 2–5d eastward propagating planetary waves is found to correlate positively with zonal‐mean zonal winds averaged over 67.5°±10°S but negatively with the quasi‐biennial oscillation (QBO) index in austral wint...

Water vapor (H2O) measurements made by the SABER instrument between 2002 and 2018 and by the MLS instrument between 2004 and 2018 are analyzed to determine the linear trend and solar cycle response of H2O in the stratosphere and mesosphere. Both SABER and MLS show a rapid global H2O increase of 5-6% per decade in the lower stratosphere after the 20...

The second Radiative Heating in Underexplored Bands Campaign (RHUBC‐II) was conducted in 2009 by the U.S. Department of Energy Atmospheric Radiation Measurement program to improve water vapor spectroscopy in the far‐infrared spectral region. RHUBC‐II was located in an extremely dry region of Chile to ensure very low opacities in this spectral regio...

Electronically excited states of molecular and atomic oxygen (O2 and O) are coupled with each other as well as with the ground states of O2 and O in the Multiple Airglow Chemistry (MAC) model representing the oxygen airglow and the oxygen photochemistry in the upper Mesosphere and Lower Thermosphere region. The MAC model couples seven O2 and three...

In January and February 2016, the OH airglow camera system FAIM (Fast Airglow Imager) measured during six flights on board the research aircraft FALCON in northern Scandinavia. Flight 1 (14 January 2016) covering the same ground track in several flight legs and flight 5 (28 January 2016) along the shoreline of Norway are discussed in detail in this...

The current progress in the detection of terrestrial type exoplanets has opened a new avenue in the characterization of exoplanetary atmospheres and in the search for biosignatures of life with the upcoming ground-based and space missions. To specify the conditions favorable for the origin, development and sustainment of life as we know it in other...

In order to understand the characteristics of long‐lasting “C‐type” structure in the Sodium (Na) lidargram, six cases from different observational locations have been analyzed. The Na lidargram, collected from low‐, middle‐, and high‐latitude sites, show long lifetime of the C‐type structures which is believed to be the manifestation of Kelvin‐Helm...

The Global UltraViolet Imager (GUVI) onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite provides a data set of vertical thermospheric composition (O, N2, and O2 densities) and temperature profiles from 2002–2007. Even though GUVI sampling is limited by orbital constraint, we demonstrated that the GUVI data set...

This paper discusses the solar cycle variation of the DE3 and DE2 nonmigrating tides in the nitric oxide (NO) 5.3 μm and carbon dioxide (CO2) 15 μm infrared cooling between 100 and 150 km altitude and ±40° latitude. Tidal diagnostics of SABER NO and CO2 cooling rate data (2002–2013) indicate DE3 (DE2) amplitudes during solar maximum are on the orde...

Based on the zero-dimensional box model Module Efficiently Calculating the Chemistry of the Atmosphere/Chemistry As A Box model Application (CAABA/MECCA-3.72f), an OH airglow model was developed to derive night-time number densities of atomic oxygen ([O(3P)]) and atomic hydrogen ([H]) in the mesopause region (∼75–100 km). The profiles of [O(3P)] an...

We use data from two NASA satellites, the Thermosphere Ionosphere Energetics and Dynamics (TIMED) and the Aeronomy of Ice in the Mesosphere (AIM) satellites, in conjunction with model simulations from the thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (TIME-GCM) to elucidate the key dynamical and chemical factors gover...

In January and February 2016, the OH-airglow camera system FAIM (Fast Airglow Imager) measured during six flights on board the research aircraft FALCON in Northern Scandinavia. Flight 1 (14th January 2016) covering the same ground track in several flight legs and flight 5 (28th January 2016) along the shoreline of Norway are discussed in detail in...

Supporting Information S1

Observations of thermospheric infrared radiative cooling by carbon dioxide (CO2) and nitric oxide (NO) from 2002 to 2018 are presented. The time span covers more than 6,000 days including most of solar cycle (SC) 23 and the entirety of SC 24 to date. Maxima of infrared cooling rate profiles (nW/m³) are smaller during SC 24 than SC 23, indicating a...

This paper presents measurements of the amplitudes and timings of the combined, annual, and semiannual variations of thermospheric neutral density, and a comparison of these density variations with measurements of the infrared emissions from carbon dioxide and nitric oxide in the thermosphere. The density values were obtained from measurements of t...

This study focuses on the effects of polar mesospheric cloud (PMC) formation on the chemical environment of the mesosphere and lower thermosphere. Of specific interest is how the dehydration due to mesospheric ice particle formation leads to significant seasonal decreases in the atomic hydrogen near the mesopause at middle to high latitudes. Using...

The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board the TIMED satellite has been continuously operating for more than 16 years, since 2002, monitoring the CO2 concentration on nearly a global scale in the middle and upper atmosphere (from 65 km up to 110 km). A recent reanalysis (Qian et al., 2017, https:/...

The National Aeronautics and Space Administration (NASA) Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) Sounding of the Atmosphere using Broadband Radiometry (SABER) instrument performs near-global measurements of the vertical kinetic temperature (Tk) profiles and volume mixing ratios of various trace species (including O3, CO2,...

An OH airglow model was developed to derive night-time atomic oxygen (O(³P)) and atomic hydrogen (H) from satellite OH airglow observations in the mesopause region (~75–100km). The OH airglow model is based on the zero dimensional box model CAABA/MECCA-3.72f and was empirically adjusted to fit four different OH airglow emissions observed by the sat...

This work uses SABER CO2 data from 2002 to 2015 and SD-WACCM model outputs from 1979 to 2014 to show, for the first time, the solar cycle response of CO2 in the Austral winter Mesosphere and Lower Thermosphere region (MLT region). Both SABER and SD-WACCM show that CO2 experiences a decrease during solar maximum throughout the Austral winter MLT reg...

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....

Updated night atomic oxygen concentration (O) profiles from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the National Aeronautics and Space Administration TIMED satellite are presented. These are derived from measurements of the OH(υ = 9 + 8) volume emission rates and photochemical balance relationships....

Gravity waves are one of the main drivers of atmospheric dynamics. The spatial resolution of most global atmospheric models, however, is too coarse to properly resolve the small scales of gravity waves, which range from tens to a few thousand kilometers horizontally, and from below 1 km to tens of kilometers vertically. Gravity wave source processe...

We present the first-ever global assessment of thermospheric nitric oxide infrared radiative flux (NOF) variability. NOF (W/m²) from 100- to 250-km altitude is extracted from 13.7 years of data from the TIMED satellite, Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, and decomposed into four empirical orthogonal f...

Infrared radiative cooling by nitric oxide (NO) and carbon dioxide (CO2) modulates the thermosphere's density and thermal response to geomagnetic storms. Satellite tracking and collision avoidance planning require accurate density forecasts during these events. Over the past several years, failed density forecasts have been tied to the onset of rap...

We investigate atomic hydrogen (H) variability from the mesopause to the upper thermosphere, on time scales of solar cycle, seasonal, and diurnal, using measurements made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere Ionosphere Mesosphere Energetics Dynamics (TIMED) satellite, and simul...

The search of life in the Universe is a fundamental problem of astrobiology and a major priority for NASA. A key area of major progress since the NASA Astrobiology Strategy 2015 (NAS15) has been a shift from the exoplanet discovery phase to a phase of characterization and modeling of the physics and chemistry of exoplanetary atmospheres, and the de...

Gravity waves are one of the main drivers of atmospheric dynamics. The spatial resolution of most global atmospheric models, however, is too coarse to properly resolve the small scales of gravity waves, which range from tens to a few thousand kilometers horizontally, and from below 1 km to tens of kilometers vertically. Gravity wave source processe...

In and near the Alpine region, the most dense subnetwork of identical NDMC (Network for the Detection of Mesospheric Change, https://www.wdc.dlr.de/ndmc/) instruments can be found: five stations are equipped with OH* spectrometers which deliver a time series of mesopause temperature for each cloudless or only partially cloudy night. These measureme...

The current explosion in detection and characterization of thousands of extrasolar planets from the Kepler mission, the Hubble Space Telescope, and large ground-based telescopes opens a new era in searches for Earth-analog exoplanets with conditions suitable for sustaining life. As more Earth-sized exoplanets are detected in the near future, we wil...

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. O...

We revisit three complex superstorms of 19-20 November 2003, 7-8 November 2004 and 9-11 November 2004 to analyze ionosphere-thermosphere (IT) effects driven by different solar wind structures associated with complex Interplanetary Coronal Mass Ejections (ICMEs) and their upstream sheaths. The efficiency of the solar wind-magnetosphere connection th...

Observations of a pair of mesospheric bore disturbances that propagated through the nighttime mesosphere over Europe are presented. The observations were made at the Padua Observatory, Asiago (45.9°N, 11.5°E) by the Boston University all-sky imager on 11 March 2013. The bores appeared over the north-west horizon, approximately 30 minutes apart, and...

In the 1970s, the mechanism of vibrational energy transfer from chemically produced OH(ν) in the nighttime mesosphere to the CO2(ν3) vibration, OH(ν)⇒N2(ν)⇒CO2(ν3), was proposed. In later studies it was shown that this “direct” mechanism for simulated nighttime 4.3 µm emissions of the mesosphere is not sufficient to explain space observations. In o...

The ionosphere-thermosphere (IT) energy partitioning for the interplanetary coronal mass ejection (ICME) storms of 16-19 March 2013 and 2015 is estimated with the Global Ionosphere-Thermosphere Model (GITM), empirical models and proxies derived from in situ measurements. We focus on auroral heating, Joule heating, and thermospheric cooling. Solar w...

In and near the Alpine region, the most dense sub-network of identical NDMC instruments (Network for the Detection of Mesospheric Change, http://wdc.dlr.de/ndmc) can be found: five stations are equipped with OH*-spectrometers which deliver a time series of mesopause temperature each cloudless or only partially cloudy night. These measurements are s...

Carbon dioxide (CO2) infrared emissions at 15 μm is the primary radiative cooling mechanism of the thermosphere in the altitude range of 100-135 km. This paper explores the role of two important diurnal nonmigrating tides, the DE2 and DE3, in the modulation of CO2 15 μm emissions during the solar minimum year 2008 by (i) analyzing Sounding the Atmo...

The global gravity wave (GW) potential energy (PE) per unit mass is derived from SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) temperature profiles over the past 14 years (2002–2015). Since the SABER data cover longer than one solar cycle, multivariate linear regression is applied to calculate the trend (means linear trend...

Thermospheric temperature and density recovery during the 5 April 2010 geomagnetic storm has been investigated in this study. Neutral density recovery as revealed by TIEGCM simulations was slower than observations from GOCE, CHAMP and GRACE satellites, suggesting that the cooling processes may not be fully represented in the model. The NO radiative...

Downwelling radiances at the Earth's surface measured by the Far-Infrared Spectroscopy of the Troposphere (FIRST) instrument in an environment with integrated precipitable water (IPW) as low as 0.03 cm are compared with calculated spectra in the far-infrared and mid-infrared. FIRST (a Fourier transform spectrometer) was deployed from August through...

We present a combination of satellite observation and high-resolution model output to understand monsoon convection as a source of high-latitude mesospheric gravity waves (GWs). The GWs generated over the Northern Hemisphere (NH) monsoon region during the 2007 summer and the role of the winds in focusing these GWs toward the high-latitude middle at...

Detecting climate trends of atmospheric temperature, moisture, cloud, and surface temperature requires accurately calibrated satellite instruments such as the Climate Absolute Radiance and Refractivity Observatory (CLARREO). Previous studies have evaluated the CLARREO measurement requirements for achieving climate change accuracy goals in orbit. Th...

The interannual variation of the ionospheric solar-quiet (Sq) current system is examined. A dense magnetometer network over Japan enables the accurate determination of the central position of the northern Sq current loop, or the Sq current focus, during 1999–2015. It is found that the Sq focus latitude undergoes an interannual variation of ±2∘ with...

We present a multiyear superposed epoch study of the Sounding of the Atmosphere using Broadband Emission Radiometry nitric oxide (NO) emission data. NO is a trace constituent in the thermosphere that acts as cooling agent via infrared (IR) emissions. The NO cooling competes with storm time thermospheric heating, resulting in a thermostat effect. Ou...