Lidar observations of CO2 concentration and temperature profiles in the lower atmosphere (Conference Presentation)

2018 ◽  
Author(s):  
Yasukuni Shibata ◽  
Chikao Nagasawa ◽  
Makoto Abo
Keyword(s):  
Co2 Concentration ◽  
Lower Atmosphere ◽  
Temperature Profiles ◽  
Lidar Observations

scholarly journals Diurnal Variations of CO2 Mixing Ratio in the Lower Atmosphere by Three Wavelength DIAL

2020 ◽  
Vol 237 ◽  
pp. 03011
Author(s):  
Yasukuni Shibata ◽  
Chikao Nagasawa ◽  
Makoto Abo
Keyword(s):  
Solar Radiation ◽  
Diurnal Variation ◽  
Diurnal Variations ◽  
The Other ◽  
Lower Atmosphere ◽  
Temperature Profiles ◽  
Mixing Ratio ◽  
Other Hand

We have conducted the measurement of high accurate CO2 mixing ratio profiles by measuring the temperature profiles simultaneously using the three wavelength CO2 DIAL. The measurements of CO2 diurnal variation in the lower atmosphere were carried out on sunny and cloudy days respectively. We find out that increasing of the CO2 mixing ratio occurs over the altitude of about 2 km from the surface during nighttime. On the other hand, the CO2 mixing ratio decreases over the lower atmosphere during daytime. In particular, the CO2 mixing ratio decreases earlier on sunny days than on cloudy days after sunrise. This result suggests that CO2 absorption by photosynthesis greatly contributes to the strength of the solar radiation.

scholarly journals Statistical Characterization of Temperature and Pressure Vertical Profiles for the Analysis of Laser Heterodyne Radiometry Data

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5421
Author(s):  
Monica M. Flores ◽  
David S. Bomse ◽  
J. Houston Miller
Keyword(s):  
Probability Distributions ◽  
Lower Atmosphere ◽  
Temperature Profiles ◽  
Time Data ◽  
Statistical Characterization ◽  
Line Shapes ◽  
Pressure Profiles ◽  
Laser Heterodyne ◽  
Temperature And Pressure ◽  
Heterodyne Radiometry

The statistical analysis of historic pressure and temperature profiles from radiosonde launches for use in the fitting of molecular oxygen line shapes is presented. As the O2 mixing ratio is nearly constant throughout the lower atmosphere, only variations in pressure and temperature profiles will affect the fit of observed O2 features in Laser Heterodyne Radiometry (LHR) spectra. Radiosonde temperature and pressure data are extracted from the Integrated Global Radiosonde Archive (IGRA) for a given station, date, and launch time. Data may be extracted for a single launch, for the same date over several years, and/or within a window centered on a target date. The temperature and pressure profiles are further characterized by the statistical variation in coefficients of polynomial fits in altitude. The properties of the probability distributions for each coefficient are used to constrain fits of O2 line shapes through Nelder–Mead optimization. The refined temperature and pressure profiles are then used in the retrieval of vertically resolved mixing ratios for greenhouse gases (GHGs) measured in the same instrument. In continuous collections, each vertical profile determination may be treated as a Bayesian prior to inform subsequent measurements and provide an estimate of uncertainties.

scholarly journals Observations of Thermally-Driven Winds in a Small Valley during the 21 August 2017 Solar Eclipse

Atmosphere ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 389 ◽  
Author(s):  
Ross T. Palomaki ◽  
Nevio Babić ◽  
Gert-Jan Duine ◽  
Michael van den Bossche ◽  
Stephan F. J. De Wekker
Keyword(s):  
Boundary Layer ◽  
Solar Eclipse ◽  
Thick Layer ◽  
Lower Atmosphere ◽  
Topographic Features ◽  
Blue Ridge Mountains ◽  
Thermally Driven ◽  
Meteorological Observations ◽  
Lidar Observations ◽  
Small Valley

On the afternoon of 21 August 2017, a partial solar eclipse occurred over the Blue Ridge Mountains in central Virginia, USA. High-resolution meteorological observations were made on the floor of a small valley to investigate the effect of eclipse-induced cooling on thermally-driven winds. Measurements taken both at the surface and in the lower atmosphere indicate cooling throughout much of the atmospheric boundary layer. Multiple surface weather stations observed wind rotations that occurred both during and after the eclipse, as wind direction shifted from upvalley to downvalley and back to upvalley. The direction of these rotations (clockwise vs. counterclockwise) varied between stations and was strongly influenced by the proximity of the stations to topographic features in the valley. Doppler lidar observations over the valley floor show a 300 m thick layer of downvalley winds that formed below a deeper layer of upvalley winds. Changes in boundary layer winds and structure during the solar eclipse are similar to changes during the morning and evening transitions. However, the subtle differences in the direction of wind rotations between diurnal- and eclipse-transition periods provided important new insights into the interaction between slope- and valley flows, incoming solar radiation, and topographic features.

scholarly journals Cooling of the mesosphere and lower thermosphere due to doubling of CO2

1998 ◽  
Vol 16 (11) ◽  
pp. 1501-1512 ◽  
Author(s):  
R. A. Akmaev ◽  
V. I. Fomichev
Keyword(s):  
Middle Atmosphere ◽  
Thermal Structure ◽  
Lower Thermosphere ◽  
Thermal Response ◽  
Co2 Concentration ◽  
Lower Atmosphere ◽  
Heating Rates ◽  
Density Reduction ◽  
Mesosphere And Lower Thermosphere ◽  
Thermospheric Dynamics

Abstract. A new parameterization of infrared radiative transfer in the 15-μm CO2 band has been incorporated into the Spectral mesosphere/lower thermosphere model (SMLTM). The parameterization is applicable to calculations of heating rates above approximately 15 km for arbitrary vertical profiles of the CO2 concentration corresponding to the surface mixing ratio in the range 150–720 ppm. The sensitivity of the mesosphere and lower thermosphere (MLT) to doubling of CO2 has been studied. The thermal response in the MLT is mostly negative (cooling) and much stronger than in the lower atmosphere. An average cooling at the stratopause is about 14 K. It gradually decreases to approximately 8 K in the upper mesosphere and again increases to about 40–50 K in the thermosphere. The cooling and associated thermal shrinking result in a substantial density reduction in the MLT that reaches 40–45% in the thermosphere. Various radiative, chemical, and dynamical feedbacks potentially important for the thermal response in the MLT are discussed. It is noted that the results of simulations are strikingly similar to observations of long-term trends in the MLT. This suggests that during the last 3–4 decades the thermal structure in the real upper atmosphere has undergone substantial changes driven by forcing comparable with that due to doubling of CO2.Key words. Meteorology and atmospheric dynamics (Climatology · Middle atmosphere dynamics · Thermospheric dynamics)

Global climate change and its ecological consequences

2017 ◽  
Author(s):  
Andrew Clarke
Keyword(s):  
Climate Change ◽  
Industrial Revolution ◽  
Global Climate ◽  
Lower Troposphere ◽  
Co2 Concentration ◽  
Lower Atmosphere ◽  
Radiation Balance ◽  
Past Century ◽  
Recent Climate ◽  
Frequent Response

The greenhouse effect is a simple consequence of an atmosphere containing gases that are transparent to visible light but which absorb infra-red radiation (radiatively active or greenhouse gases). The temperature of the lower troposphere is set by the radiation balance at the top of the atmosphere, and is determined predominantly by the CO2 concentration. Man has been adding radiatively active gases to the atmosphere since the Industrial Revolution, and this has led to an increase in the energy in the lower atmosphere, and thus a rise in its temperature. The bulk of the extra energy (~90%) has entered the ocean, which has also warmed significantly over the past century. The rate and extent of warming varies across the planet, depending on local circumstances. Palaeoecological studies have shown that changes in distribution have been a frequent response to climate change, though this requires somewhere for the organisms to move to. Many organisms have shifted their distribution in response to recent climate change. Many organisms have also shifted the timing of life-cycle events (phenology), with migration, breeding in animals, and germination, emergence, leafing and flowering in plants all occurring earlier in some (but not all) species. There are also changes in size, with some species becoming smaller as the climate warms.

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