Gen Inoue

Weak Northern and Strong Tropical Land Carbon Uptake from Vertical Profiles of Atmospheric CO2

Measurements of midday vertical atmospheric CO2 distributions reveal annual-mean vertical CO2 gradients that are inconsistent with atmospheric models that estimate a large transfer of terrestrial carbon from tropical to northern latitudes. The three models that most closely reproduce the observed annual-mean vertical CO2 gradients estimate weaker northern uptake of –1.5 petagrams of carbon per year (Pg C year–1) and weaker tropical emission of +0.1 Pg C year–1 compared with previous consensus estimates of –2.4 and +1.8 Pg C year–1, respectively. This suggests that northern terrestrial uptake of industrial CO2 emissions plays a smaller role than previously thought and that, after subtracting land-use emissions, tropical ecosystems may currently be strong sinks for CO2.

Characteristics of cirrus clouds from ICESat/GLAS observations

[1]xa0Cloud observations from the Geoscience Laser Altimeter System (GLAS) revealed characteristics of cirrus clouds in boreal autumn 2003. The vertical distribution of the central altitude of cirrus peaks 2 km below the climatological tropopause, which is 14.5 km in the tropics and 9.5 km in the northern midlatitudes. The mean location of the peak in deep convection is north of the Equator (7.5°N) but the top of zonally averaged cirrus is almost constant at 14.5 km in the tropics. This suggests that the height of tropical cirrus is closely linked to anvil cirrus from deep convection and lower temperatures in the tropopause symmetric with respect to the Equator. Cirrus clouds in the midlatitudes have a greater optical depth than those at other latitudes. The zonally averaged thickness of cirrus is about 1.6 km regardless of latitude.

A Lightweight Observation System for Atmospheric Carbon Dioxide Concentration Using a Small Unmanned Aerial Vehicle

Abstract To make the investigation of the temporal and spatial variations of atmospheric CO2 in and above the planetary boundary layer more flexible and economical, a lightweight observation system using a small unmanned aerial vehicle has been developed whose flight path is preset using GPS. The total weight of the CO2 measurement device carried inside the vehicle is about 3.5 kg. The device is equipped with both flow and pressure controllers and can be used to measure atmospheric CO2 from the ground surface to a maximum altitude of about 3000 m. The response time of the instrument is about 20 s, with a precision of about ±0.26 ppm. The observation system is easy to handle and can be easily and quickly deployed at a site to make frequent measurements in and above the boundary layer. Compared to the deployment of a piloted aircraft the system shows distinctive advantages, in addition to being more affordable. To test the system, preliminary measurements over a boreal forest area in Japan in the summer of ...

Distribution of tropospheric methane over Siberia in July 1993

Airborne observations of atmospheric methane (CH4) mixing ratid were carried out over Siberia during July 15-30, 1993, using a continuous measurement system. The distribution of CH 4 in the upper troposphere at an altitude of about 7 km was highly variable (1.72-1.91 parts per million, or ppm), being affected by intrusion of stratospheric air, long-range transport of CH 4 from the source region, and a synoptic-scale mixing process. During flights along nearly constant latitude between Yakutsk (62.10°N, 129.50°E) and Nizhnevartovsk (60.57°N, 76.40°E) on July 19 and 28 we observed large-scale enhancements of CH 4 from near 90° to 100°E with a horizontal scale of more than 500 km. Accompanied by high humidity and low mixing ratios of CO 2 and O 3 , the air masses with enhanced CH 4 mixing ratio were considered to be affected by lower tropospheric air. The probable source region of the CH 4 was inferred to be the West Siberian Lowland, which contains vast wetlands and huge oil/gas fields. The distribution of CH 4 in the lower troposphere (0.1-3 km) over the boreal wetlands in the West Siberian Lowland, ranging from 1.85 ppm to 2.75 ppm, showed large accumulations near the ground in the morning. The short-term temporal variations in the vertical profile of CH 4 mixing ratio revealed that the accumulated CH 4 was transported to the free troposphere with the growth of the mixed layer. On the other hand, the distribution of CH 4 (0.1-1 km) over the tundra areas in the Siberian Arctic was less variable (1.81-1.84 ppm), and little accumulation was observed.

Effective interaction energy of water dimer at room temperature: An experimental and theoretical study

Buffer-gas pressure broadening for the nu(1)+nu(3) band of H(2)O at 1.34-1.44 mum for a variety of buffer gases was investigated at room temperature using continuous-wave cavity ring-down spectroscopy. The effective interaction energy of water dimer under room temperature conditions was evaluated from the pressure broadening coefficients for rare gases using Permenter-Seavers relation. Monte Carlo simulations were performed using ab initio molecular orbital calculations to evaluate the interaction energies for the water dimer at 300 K. In this theoretical calculation, the orientations of the two water molecules were statistically treated.

Use of Landsat TM/ETM+ to monitor the spatial and temporal extent of spring breakup floods in the Lena River, Siberia

A warmer-than-normal air temperature enhances the probability of extreme hydrologic events. A spring breakup flood is among the most serious hydrologic events in high-latitude regions. This study examined the use of Landsat Thematic Mapper/Enhanced Thematic Mapper Plus (TM/ETM+) to monitor the spatial and temporal extent of spring breakup floods in the Lena River, Siberia. Although the 30 m spatial resolution of Landsat produced a detailed mapping of the floodplain, acquisition of Landsat images at short-term intervals was difficult because of the long revisit time of Landsat (16 days) and the frequent cloud cover over Siberia. However, information from two sensors (i.e. TM and ETM+) was combined to essentially halve the revisit time. Moreover, frequent Landsat images were acquired at higher latitudes by using information from overlap areas between neighbouring path images. Therefore, the average revisit time was determined to be 2.6 (= 16/3/2) days in the triple overlap area using two sensors. Updated data sets with a high temporal frequency enhanced the ability to monitor the spatial and temporal extent of the spring breakup floods, although the area was small. In addition, the neighbouring Landsat images themselves were used for large-scale monitoring of breakup floods, given that Landsat overpasses from west to east operating in a near-polar sun-synchronous orbit with a progression speed that is almost the same as the speed of a spring breakup flood. In 2007, spring breakup floods were successively monitored from Solyanka to Yakutsk. Reliable and timely information for large-area monitoring of floods was crucial to understand better the influence on regional hydrology and climate. The images from Landsat TM/ETM+ sensors were regarded as a suitable data source for operational use in flood monitoring due to the wide geographic coverage, high temporal resolution, adequate spatial resolution, and minimal cost.

Spinal fusion on adolescent idiopathic scoliosis patients with the level of L4 or lower can increase lumbar disc degeneration with sagittal imbalance 35 years after surgery

Introduction The purpose of this study was to investigate the long-term incidence of lumbar disc degeneration and Modic changes in the non-fused segments of patients with adolescent idiopathic scoliosis (AIS) who previously underwent spinal fusion. Methods Study subjects consisted of 252 patients with AIS who underwent spinal fusion between 1968 and 1988. Of 252 patients, 35 subjects underwent lumbar spine MRI and whole spine X-ray examination. The mean patient age at the time of follow-up was 49.8 years, with an average follow-up period of 35.1 years. We classified the subjects into two groups based on the lowest fused vertebra: H group whose lowest fused vertebra was L3 or higher levels and L group whose lowest fused vertebra was L4 or lower levels. Results The L group had significantly advanced disc degeneration on MRI. There was no significant difference between two groups in Modic changes. The L group showed less lumbar lordosis than the H group (H group: 48.1 degrees; and L group: 32.1 degrees) and greater SVA (H group: 1.2 cm; and L group: 5.5 cm). Conclusions In AIS patients, 35 years after spinal fusion surgery on average, we evaluated lumbar disc degeneration and Modic changes of the non-fused segments. In patients with the lowest fusion level at L4 or lower, there were reduced lumbar lordosis, considerable SVA imbalance, and severe disc degeneration compared with those with the lowest fusion level at L3 or higher. The lowest fusion level at L3 or higher is recommended to reduce disc degeneration in midlife.

Measurement of carbon dioxide flux from tropical peatland in Indonesia using the nocturnal temperature-inversion trap method

Evaluation of CO2 flux from peatland soil respiration is important to understand the effect of land use change on the global carbon cycle and climate change and particularly to support carbon emission reduction policies. However, quantitative estimation of emitted CO2 fluxes in Indonesia is constrained by existing field data. Current methods for CO2 measurement are limited by high initial cost, manpower, and the difficulties associated with construction issues. Measurement campaigns were performed using a newly developed nocturnal temperature-inversion trap method, which measures the amount of CO2 trapped beneath the nocturnal inversion layer, in the dry season of 2013 at a drained tropical peatland near Palangkaraya, Central Kalimantan, Indonesia. This method is cost-effective and data processing is easier than other flux estimation methods. We compared CO2 fluxes measured using this method with the published data from the existing eddy covariance and closed chamber methods. The maximum value of our measurement results was 10% lower than maximum value of eddy covariance method and average value was 6% higher than average of chamber method in drained tropical peatlands. In addition, the measurement results shows good correlation with groundwater table. The results of this comparison suggest that this methodology for the CO2 flux measurement is useful for field research in tropical peatlands.

Attempt to identify sources of atmospheric methane and carbon dioxide concentrations found in in situ aircraft measurements over Southern Australia

[1]xa0Identifying the sources and sinks of methane and carbon dioxide is important for understanding processes within the Earths climate system. This paper attempts to use back trajectories to identify sources of atmospheric methane and carbon dioxide as measured by high resolution in situ gas analyzers during aircraft ascents and descents in Southern Australia. Results from the back trajectory analysis were confirmed by also performing a forward trajectory analysis on some of the data. The in situ aircraft measurements were part of a joint Japanese-Australia field campaign in March and April 2007 near Adelaide, South Australia. The vertical profiles showed considerable variation in methane and carbon dioxide content above the planetary boundary layer. We used back trajectories based on an atmospheric transport model to derive the origin of the air masses which enabled speculation about sources of the gases. We were thus able to identify emission from the volcanoes on Reunion Island in the Indian Ocean and the seafloor hydrothermal activity in the Southeast Indian Ridge, confirming speculations published earlier by other research teams.

Disturbances and their corrections in space observation with GOSAT Fourier transform spectrometer

GOSAT (Greenhouse Gases Observing Satellite) is a satellite to measure greenhouse gases from space with the Fourier Transform Spectrometer (FTS). It measures spectra of Earth-reflected solar radiations with high spectral resolution of about 0.2 cm-1, covering four spectral bands, including 0.76, 1.6, 2.0 and 14 micron wavelength regions. In first three bands, we have two detectors for measuring two components of polarization. For the acquisition of one interferogram, it takes 4 seconds or less, depending on the definition of measurement mode. Since the satellite moves in high speed, an image motion compensation mirror (IMC) works to continuously stare the same position on the Earth surface during this period of acquisition. For staring same position, the mirror is controlled by two-axis motors. Staring position could slightly fluctuate around the right position, making the position of the instantaneous filed of view (IFOV) vibrate with an amplitude of a few hundreds meters. Since the optical characteristics (such as the albedo) of the IFOV changes place-by-place, the intensity of IFOV could also change due to this fluctuation. The intensity of IFOV could also change due to the change of reflection angle, wind on the water surface, or other causes. During this period of the acquisition, the optical path length and Doppler shift caused by the satellite moving could also change. In this paper, we examine the effects of some of these kinds of disturbances to the signals of interferograms on resultant spectra and retrieval accuracies of CO2, and discuss about the correction method to the interferogram and spectra.