scholarly journals Development of an Atmospheric Carbon Dioxide Standard Gas Saving System and Its Application to a Measurement at a Site in the West Siberian Forest

2010 ◽  
Vol 27 (5) ◽  
pp. 843-855 ◽  
Author(s):  
T. Watai ◽  
T. Machida ◽  
K. Shimoyama ◽  
O. Krasnov ◽  
M. Yamamoto ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Boundary Layer ◽  
Atmospheric Carbon Dioxide ◽  
Western Siberia ◽  
Atmospheric Stability ◽  
Co2 Concentration ◽  
Atmospheric Conditions ◽  
The West ◽  
A Site ◽  
Standard Gas

Abstract Observations of the atmospheric CO2 concentration from a 90-m tower in Berezorechka, western Siberia, that have taken place since October 2001 were used to characterize CO2 variations over a vast boreal forest area. A new CO2 standard gas saving system was developed that reduced the consumption of standard gases and kept the analysis precision to within 0.3 μmol mol−1. The CO2 day-to-day variation correlated well with atmospheric stability. The average amplitudes of the diurnal variation at 80 m were found to be about 17 and 1.5 μmol mol−1 in July and December 2003, respectively. Extremely high daytime CO2 concentrations of greater than 400 μmol mol−1 were occasionally observed during the winter, which were caused by anticyclonic atmospheric conditions lasting more than several days. Afternoon CO2 values observed at the 80-m height agreed to within 0.4 μmol mol−1 with aircraft CO2 measurements taken in the planetary boundary layer; disagreements were found for anticyclonic conditions in the winter. The afternoon CO2 values reached their maximum in mid-January and their minimum late in July, with the seasonal amplitude of 30.9 μmol mol−1. Compared to observations at background stations, this observation tower recorded a larger seasonal amplitude and earlier occurrence of the seasonal minimum.

Ammonium application mitigates the effects of elevated carbon dioxide on the carbon/nitrogen balance of Phoebe bournei seedlings

2021 ◽  
Author(s):  
Xiao Wang ◽  
Xiaoli Wei ◽  
Gaoyin Wu ◽  
Shengqun Chen
Keyword(s):  
Carbon Dioxide ◽  
Enzyme Activities ◽  
Atmospheric Carbon Dioxide ◽  
Global Climate ◽  
Co2 Concentration ◽  
Rubisco Activase ◽  
Plant Responses ◽  
N Metabolism ◽  
C And N ◽  
Phoebe Bournei

Abstract The study of plant responses to increases in atmospheric carbon dioxide (CO2) concentration is crucial to understand and to predict the effect of future global climate change on plant adaptation and evolution. Increasing amount of nitrogen (N) can promote the positive effect of CO2, while how N forms would modify the degree of CO2 effect is rarely studied. The aim of this study was to determine whether the amount and form of nitrogen (N) could mitigate the effects of elevated CO2 (eCO2) on enzyme activities related to carbon (C) and N metabolism, the C/N ratio, and growth of Phoebe bournei (Hemsl.) Y.C. Yang. One-year-old P. bournei seedlings were grown in an open-top air chamber under either an ambient CO2 (aCO2) (350 ± 70 μmol•mol−1) or an eCO2 (700 ± 10 μmol•mol−1) concentration and cultivated in soil treated with either moderate (0.8 g per seedling) or high applications (1.2 g per seedling) of nitrate or ammonium. In seedlings treated with a moderate level of nitrate, the activities of key enzymes involved in C and N metabolism (i.e., Rubisco, Rubisco activase and glutamine synthetase) were lower under eCO2 than under aCO2. By contrast, key enzyme activities (except GS) in seedlings treated with high nitrate or ammonium were not significantly different between aCO2 and eCO2 or higher under eCO2 than under aCO2. The C/N ratio of seedlings treated with moderate or high nitrate under eCO2was significantly changed compared with the seedlings grown under aCO2, whereas the C/N ratio of seedlings treated with ammonium was not significantly different between aCO2 and eCO2. Therefore, under eCO2, application of ammonium can be beneficial C and N metabolism and mitigate effects on the C/N ratio.

scholarly journals Surface flux estimates derived from UAS-based mole fraction measurements by means of a nocturnal boundary layer budget approach

2019 ◽  
Author(s):  
Martin Kunz ◽  
Jost V. Lavric ◽  
Rainer Gasche ◽  
Christoph Gerbig ◽  
Richard H. Grant ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Boundary Layer ◽  
Mole Fraction ◽  
Surface Flux ◽  
Nocturnal Boundary Layer ◽  
Carbon Dioxide Flux ◽  
Unmanned Aircraft ◽  
Atmospheric Conditions ◽  
Transport Modelling ◽  
Stable Conditions

Abstract. The carbon exchange between ecosystems and the atmosphere has a large influence on the Earth system and specifically on the climate. This exchange is therefore being studied intensively, often using the eddy covariance (EC) technique. EC measurements provide reliable results under turbulent atmospheric conditions, but under stable conditions – as they often occur at night – these measurements are known to misrepresent exchange fluxes. Nocturnal boundary layer (NBL) budgets can provide independent flux estimates under stable conditions, but their application so far has been limited by rather high cost and practical difficulties. Unmanned aircraft systems (UASs) equipped with trace gas analysers have the potential to make this method more accessible. We present the methodology and results of a proof of concept study carried out during the ScaleX 2016 campaign. Successive vertical profiles of carbon dioxide dry air mole fraction in the NBL were taken with a compact analyser carried by a UAS. We estimate an average carbon dioxide flux of 12 μmol m−2 s−1, which is plausible for nocturnal respiration in this region in summer. Transport modelling suggests that the NBL budgets represent an area on the order of 100 km2.

scholarly journals Soil Moisture-Boundary Layer Feedbacks on the Loess Plateau in China Using Radiosonde Data with 1-D Atmospheric Boundary Layer Model

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1619
Author(s):  
Yingsai Ma ◽  
Xianhong Meng ◽  
Yinhuan Ao ◽  
Ye Yu ◽  
Guangwei Li ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Soil Moisture ◽  
Atmospheric Boundary Layer ◽  
Loess Plateau ◽  
Atmospheric Stability ◽  
Heat Fluxes ◽  
Radiosonde Data ◽  
Atmospheric Conditions ◽  
The Loess Plateau ◽  
The Impact

The Loess Plateau is one land-atmosphere coupling hotspot. Soil moisture has an influence on atmospheric boundary layer development under specific early-morning atmospheric thermodynamic structures. This paper investigates the sensitivity of atmospheric convection to soil moisture conditions over the Loess Plateau in China by using the convective triggering potential (CTP)—humidity index (HIlow) framework. The CTP indicates atmospheric stability and the HIlow indicates atmospheric humidity in the low-level atmosphere. By comparing the model outcomes with the observations, the one-dimensional model achieves realistic daily behavior of the radiation and surface heat fluxes and the mixed layer properties with appropriate modifications. New CTP-HIlow thresholds for soil moisture-atmosphere feedbacks are found in the Loess Plateau area. By applying the new thresholds with long-time scales sounding data, we conclude that negative feedback is dominant in the north and west portion of the Loess Plateau; positive feedback is predominant in the south and east portion. In general, this framework has predictive significance for the impact of soil moisture on precipitation. By using this new CTP-HIlow framework, we can determine under what atmospheric conditions soil moisture can affect the triggering of precipitation and under what atmospheric conditions soil moisture has no influence on the triggering of precipitation.

scholarly journals Surface flux estimates derived from UAS-based mole fraction measurements by means of a nocturnal boundary layer budget approach

2020 ◽  
Vol 13 (4) ◽  
pp. 1671-1692 ◽  
Author(s):  
Martin Kunz ◽  
Jost V. Lavric ◽  
Rainer Gasche ◽  
Christoph Gerbig ◽  
Richard H. Grant ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Boundary Layer ◽  
Mole Fraction ◽  
Surface Flux ◽  
Nocturnal Boundary Layer ◽  
Carbon Dioxide Flux ◽  
Unmanned Aircraft ◽  
Atmospheric Conditions ◽  
Transport Modelling ◽  
Stable Conditions

Abstract. The carbon exchange between ecosystems and the atmosphere has a large influence on the Earth system and specifically on the climate. This exchange is therefore being studied intensively, often using the eddy covariance (EC) technique. EC measurements provide reliable results under turbulent atmospheric conditions, but under calm and stable conditions – as they often occur at night – these measurements are known to misrepresent exchange fluxes. Nocturnal boundary layer (NBL) budgets can provide independent flux estimates under stable conditions, but their application so far has been limited by rather high cost and practical difficulties. Unmanned aircraft systems (UASs) equipped with trace gas analysers have the potential to make this method more accessible. We present the methodology and results of a proof-of-concept study carried out during the ScaleX 2016 campaign. Successive vertical profiles of carbon dioxide dry-air mole fraction in the NBL were taken with a compact analyser carried by a UAS. We estimate an average carbon dioxide flux of 12 µmolm-2s-1, which is plausible for nocturnal respiration in this region in summer. Transport modelling suggests that the NBL budgets represent an area on the order of 100 km2.

scholarly journals INVESTIGATING THE HISTORICAL CORRELATION BETWEEN ATMOSPHERIC CARBON DIOXIDE CONCENTRATION AND GLOBAL TEMPERATURE CHANGE

2021 ◽  
pp. 5-16
Author(s):  
Kneev Sharma ◽  
Dimitre Karamanev
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Temperature Rise ◽  
Atmospheric Carbon Dioxide ◽  
Carbon Dioxide Concentration ◽  
Co2 Concentration ◽  
Global Temperature ◽  
Atmospheric Carbon Dioxide Concentration ◽  
Important Relationship ◽  
Atmospheric Carbon

Understanding the fundamental relationship between atmospheric carbon dioxide concentration and temperature rise is essential for tackling the problem of climate change that faces us today. Misconceptions regarding the relationship are widespread due to media and political influences. This investigation aims to address the popular misconception that CO2 concentration directly and naturally leads to global temperature rise. While anthropogenic CO2 emissions seem to affect the rising global atmospheric temperature with a confidence of 95%, it falters when the historical relationship using ice core data is studied. This investigation uses two statistical approaches to determine an accurate range and direction for this important relationship. Through a combined approach, it was found that historically CO2 concentration in the last 650 000 years lags global temperature rise by 1020-1080 years with a maximum correlation coefficient of 0.8371-0.8372. This result is important for the investigation of climate change.

Effects of Elevated Carbon Dioxide Levels and Temperature on the Life History of the Madeira Mealybug (Hemiptera: Pseudococcidae)

2004 ◽  
Vol 39 (3) ◽  
pp. 387-397 ◽  
Author(s):  
Juang-Horng Chong ◽  
Marc W. van lersel ◽  
Ronald D. Oetting
Keyword(s):  
Carbon Dioxide ◽  
Chemical Composition ◽  
Elevated Co2 ◽  
Atmospheric Carbon Dioxide ◽  
Host Plants ◽  
Co2 Concentration ◽  
Reproductive Period ◽  
Elevated Co2 Concentration ◽  
Elevated Atmospheric Co2 ◽  
Co2 Level

Atmospheric carbon dioxide concentrations and temperatures are increasing and, thus, the interactions between insect herbivores and their host plants in environments of elevated CO2 concentration and temperature must be examined. We investigated the combined effects of elevated atmospheric CO2 concentration (400 and 700 μmol mol−1) and temperature (20, 25 and 30°C) on the development, survival and reproduction of two generations of the Madeira mealybug, Phenacoccus madeirensis Green, and the chemical composition of chrysanthemum, Dendranthema × grandiflora Kitam., leaves. The development of the mealybugs was temperature-driven and was not influenced by the CO2 level or the number of generations. At higher temperatures, the duration to egg eclosion and the developmental time of adult females and males were significantly shortened. More eggs survived to adulthood at higher temperatures. Temperature had no influence on the egg eclosion percentage. The reproductive period of females was shortest at 30°C, while fecundity was highest at 20°C. There was a significantly higher proportion of females at the end of the experiment at lower than at higher temperatures. Elevated CO2 level and temperature did not change the chemical composition (nitrogen and carbon concentrations, and carbon-nitrogen ratio) of the host plants. Relative water content of the leaf tissues was higher at 30°C than other temperature treatments. Our results show that the effects of temperature on the biology of the Madeira mealybug were stronger than that of the elevated CO2 concentration.

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

2006 ◽  
Vol 23 (5) ◽  
pp. 700-710 ◽  
Author(s):  
T. Watai ◽  
T. Machida ◽  
N. Ishizaki ◽  
G. Inoue
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Unmanned Aerial Vehicle ◽  
Atmospheric Carbon Dioxide ◽  
Carbon Dioxide Concentration ◽  
Ground Surface ◽  
Atmospheric Co2 ◽  
Observation System ◽  
Aerial Vehicle ◽  
A Site

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 2000 have been conducted. The results indicate that the unmanned aerial vehicle measurement system provides an affordable platform that can be used to obtain quantitative understanding of the temporal and vertical variations of atmospheric CO2 in and above the planetary boundary layer.

scholarly journals On the turbulent structure of the marine atmospheric boundary layer from CBLAST Nantucket measurements

2013 ◽  
Vol 10 (3) ◽  
pp. 210-217
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Land Surface ◽  
Atmospheric Stability ◽  
Heat Fluxes ◽  
Turbulent Structure ◽  
Atmospheric Conditions ◽  
Turbulent Characteristics ◽  
Momentum Fluxes

In this work preliminary results on the characteristics of the turbulent structure of the Marine Atmospheric Boundary Layer (MABL) are presented. Measurements used here were conducted in the framework of the Coupled Boundary Layers Air-Sea Transfer Experiment in Low Wind (CBLAST-Low) project. A number of in situ (fast and slow sensors) and remote sensing (SODAR) instruments were deployed on the coast of Nantucket Island, MA, USA. Measurements of the mean wind, the variances of the three wind components, the atmospheric stability and the momentum fluxes from the acoustic radar (SODAR) revealed the variation of the depth, the turbulent characteristics, and the stability of the MABL in response to the background flow. More specifically, under light south-southwesterly winds, which correspond to the MABL wind directions, the atmosphere was very stable and low values of turbulence were observed. Under moderate to strong southwesterly flow, less stable and neutral atmospheric conditions appeared and the corresponding turbulent quantities were characterized by higher values. The SODAR measurements, with high temporal and spatial resolution, also indicated large magnitude of momentum fluxes at higher levels, presumably associated with the shear forcing near the developed low-level jet. The measurements from the in-situ instrumentation confirmed that the MABL typically has small negative momentum and sensible heat fluxes consistent with stable to neutral stratification while strong diurnal variations were typical for the land surface Atmospheric Boundary Layer (ABL). The developed internal ABL at the experimental site was in general less than 10m during the night and could reach 15m heights during the day, particularly under low-wind conditions.

Carbon dioxide atmospheric concentration and hydrometeorological disasters

2021 ◽  
Author(s):  
Andres Fortunato ◽  
Helmut Herwartz ◽  
Ramón E. López ◽  
Eugenio Figueroa
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Co2 Concentration ◽  
Cointegration Analysis ◽  
Atmospheric Concentration ◽  
Bayesian Sampling ◽  
Term Relation ◽  
Long Run ◽  
Socio Demographic Factors ◽  
Carbon Dioxide Co2

Abstract We study the long-run dynamic and predictive connection between atmospheric carbon dioxide (CO2) concentration and the probability of hydrometeorological disasters. For a panel of 193 countries over the period 1970-2016 we estimate the probabilities of hydrometeorological disasters at country levels by means of Bayesian sampling techniques. We then separate the effects of climatological and socio-demographic factors (used as proxies for exposure and vulnerability) and other country-specific factors, from a global probability of disasters (GPOD). Finally, we subject these global probability time paths to a cointegration analysis with CO2 concentration and run projections to year 2040 of the GPOD conditional on nine Shared Socioeconomic Pathways scenarios. We detect a stable long-term relation between CO2 accumulation and the GPOD that allows to determine projections of the latter process conditional on the former. This way, we demonstrate that generally and readily available statistical data on CO2 global atmospheric concentrations can be used as a conceptually meaningful, statistically valid and policy useful predictor of the probability of occurrence of (global) hydrometeorological disasters.

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