scholarly journals Observed decreases in on-road CO<sub>2</sub> concentrations in Beijing during COVID-19

2020 ◽  
Author(s):  
Di Liu ◽  
Wanqi Sun ◽  
Ning Zeng ◽  
Pengfei Han ◽  
Bo Yao ◽  
...  
Keyword(s):  
Background Level ◽  
Working Hours ◽  
Co2 Concentration ◽  
Mobile Platforms ◽  
Urban Regions ◽  
Co2 Concentrations ◽  
Transportation Emissions ◽  
The Difference ◽  
Academy Of Sciences ◽  
Future Work

Abstract. To prevent the spread of the COVID-19 epidemic, restrictions such as lockdown, were conducted globally, which led to significant reduction in fossil fuel emissions, especially in urban regions. However, CO2 concentrations in urban regions are affected by many factors, such as weather and background CO2 fluctuations. Thus, it is difficult to directly observe the reductions in CO2 concentrations with sparse ground observations. Here, we focus on urban ground transportation emissions, which were dramatically affected by the prohibitions, to determine the reduction signals. We conducted six on-road CO2 observations in Beijing using mobile platforms before (BC), during (DC) and after COVID-19 prohibitions (AC). To reduce the weather and background impacts, we chose trips with the most similar weather as possible and calculated the enhancement, which mean the difference in the CO2 concentration between on-road and the background level measured at the Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP) tower. The results showed that DC CO2 enhancement decreased by 41 parts per million (ppm) and 26 ppm compared to those during BC and AC, respectively, after eliminating the fluctuations in CO2 concentrations on polluted days. Detailed analysis showed that, during COVID, there was no difference between weekdays and weekends. The enhancements during rush hours were almost twice those during working hours, indicating that emissions during rush hours were much higher. Compared with DC and BC, the reductions in the enhancements during rush hours were much larger than those during working hours. Our findings showed a clear decrease during COVID, which are consistent with the CO2 concentration and emissions reductions due to the pandemic. The enhancement way used in this study is an effective method to reduce the impacts of weather and background fluctuation and should be regularly and more frequently conducted in future work.

scholarly journals Observed decreases in on-road CO<sub>2</sub> concentrations in Beijing during COVID-19 restrictions

2021 ◽  
Vol 21 (6) ◽  
pp. 4599-4614
Author(s):  
Di Liu ◽  
Wanqi Sun ◽  
Ning Zeng ◽  
Pengfei Han ◽  
Bo Yao ◽  
...  
Keyword(s):  
Urban Areas ◽  
Low Cost ◽  
Working Hours ◽  
Weather Conditions ◽  
Co2 Concentration ◽  
Mobile Platforms ◽  
Local Standard ◽  
Transportation Emissions ◽  
Enhancement Method ◽  
The Difference

Abstract. To prevent the spread of the COVID-19 epidemic, restrictions such as “lockdowns” were conducted globally, which led to a significant reduction in fossil fuel emissions, especially in urban areas. However, CO2 concentrations in urban areas are affected by many factors, such as weather, biological sinks and background CO2 fluctuations. Thus, it is difficult to directly observe the CO2 reductions from sparse ground observations. Here, we focus on urban ground transportation emissions, which were dramatically affected by the restrictions, to determine the reduction signals. We conducted six series of on-road CO2 observations in Beijing using mobile platforms before (BC), during (DC) and after (AC) the implementation of COVID-19 restrictions. To reduce the impacts of weather conditions and background fluctuations, we analyze vehicle trips with the most similar weather conditions possible and calculated the enhancement metric, which is the difference between the on-road CO2 concentration and the “urban background” CO2 concentration measured at the tower of the Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences. The results showed that the DC CO2 enhancement was decreased by 41 (±1.3) parts per million (ppm) and 26 (±6.2) ppm compared to those for the BC and AC trips, respectively. Detailed analysis showed that, during COVID-19 restrictions, there was no difference between weekdays and weekends during working hours (09:00–17:00 local standard time; LST). The enhancements during rush hours (07:00–09:00 and 17:00–20:00 LST) were almost twice those during working hours, indicating that emissions during rush hours were much higher. For DC and BC, the enhancement reductions during rush hours were much larger than those during working hours. Our findings showed a clear CO2 concentration decrease during COVID-19 restrictions, which is consistent with the CO2 emissions reductions due to the pandemic. The enhancement method used in this study is an effective method to reduce the impacts of weather and background fluctuations. Low-cost sensors, which are inexpensive and convenient, could play an important role in further on-road and other urban observations.

scholarly journals Effects of Climatic Conditions, Season and Environmental Factors on CO2 Concentrations in Naturally Ventilated Primary Schools in Chile

2021 ◽  
Vol 13 (8) ◽  
pp. 4139
Author(s):  
Muriel Diaz ◽  
Mario Cools ◽  
Maureen Trebilcock ◽  
Beatriz Piderit-Moreno ◽  
Shady Attia
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Primary Schools ◽  
Co2 Concentration ◽  
Building Design ◽  
Climatic Conditions ◽  
Indoor Environmental Quality ◽  
Co2 Concentrations ◽  
The Impact

Between the ages of 6 and 18, children spend between 30 and 42 h a week at school, mostly indoors, where indoor environmental quality is usually deficient and does not favor learning. The difficulty of delivering indoor air quality (IAQ) in learning facilities is related to high occupancy rates and low interaction levels with windows. In non-industrialized countries, as in the cases presented, most classrooms have no mechanical ventilation, due to energy poverty and lack of normative requirements. This fact heavily impacts the indoor air quality and students’ learning outcomes. The aim of the paper is to identify the factors that determine acceptable CO2 concentrations. Therefore, it studies air quality in free-running and naturally ventilated primary schools in Chile, aiming to identify the impact of contextual, occupant, and building design factors, using CO2 concentration as a proxy for IAQ. The monitoring of CO2, temperature, and humidity revealed that indoor air CO2 concentration is above 1400 ppm most of the time, with peaks of 5000 ppm during the day, especially in winter. The statistical analysis indicates that CO2 is dependent on climate, seasonality, and indoor temperature, while it is independent of outside temperature in heated classrooms. The odds of having acceptable concentrations of CO2 are bigger when indoor temperatures are high, and there is a need to ventilate for cooling.

scholarly journals IX. An account of trigonometrical operations in the years 1821, 1822 and 1823, for determining the difference of longitude between the Royal Observatories of Paris and Greenwich

1828 ◽  
Vol 118 ◽  
pp. 153-239 ◽  
Keyword(s):  
Royal Society ◽  
Royal Academy ◽  
The Difference ◽  
Academy Of Sciences ◽  
The Church ◽  
Royal Society Of London

In the year 1790, a series of trigonometrical operations was carried on by General Roy, in co-operation with Messrs. De Cassini, Mechain, and Legendre, for the purpose of connecting the meridians of Paris and Greenwich. In England, the work commenced with a base measured on Hounslow Heath, whence triangles were carried through Hanger Hill Tower and Severndroog Castle on Shooter’s Hill, to Fairlight Down, Folkstone Turnpike, and Dover Castle on the English coast; which last stations were connected with the church of Notre Dame at Calais, and with Blancnez and Montlambert upon the coast of France. An account of these operations will be found in the Philosophical Transactions for 1790. In the year 1821, the Royal Academy of Sciences and the Board of Longitude at Paris communicated to the Royal Society of London their desire, that the operations for connecting the meridians of Paris and Greenwich should be repeated jointly by both countries, and that commissioners should be nominated by the Royal Academy of Sciences and by the Royal Society of London for that purpose. This proposal having been readily acceded to, Messrs. Arago and Matthieu were chosen on the part of the Royal Academy of Sciences, and Lieut.-Colonel (then Captain) Colby and myself were appointed by the Royal Society to co-operate with them.

The difference in CO2 adsorption capacities of different functionalized pillar-layered metal-organic frameworks (MOFs)

2021 ◽  
Author(s):  
Xiang-Jing Gao ◽  
Hegen Zheng
Keyword(s):  
Co2 Adsorption ◽  
Metal Organic Frameworks ◽  
Co2 Concentration ◽  
Fossil Energy ◽  
Adsorption Capacities ◽  
Metal Organic ◽  
The Difference

The excessive use of fossil energy has caused the CO2 concentration in the atmosphere to increase year by year. MOFs are ideal CO2 adsorbents that can be used in CO2...

scholarly journals Unprecedented strength of Hadley circulation in 2015–2016 impacts on CO<sub>2</sub> interhemispheric difference

2018 ◽  
Author(s):  
Jorgen S. Frederiksen ◽  
Roger J. Francey
Keyword(s):  
Global Warming ◽  
Hadley Circulation ◽  
Co2 Concentration ◽  
Transport Processes ◽  
Boreal Summer ◽  
Boreal Winter ◽  
Advective Transport ◽  
Interhemispheric Difference ◽  
Eddy Transport ◽  
The Difference

Abstract. The extreme El Niño of 2015 and 2016 coincided with record global warming and unprecedented strength of the Hadley circulation with significant impact on mean interhemispheric (IH) transport of CO2 and on the difference in CO2 concentration between Mauna Loa and Cape Grim (Cmlo-cgo). The relative roles of eddy transport and mean advective transport on IH CO2 annual differences from 1992 through to 2016 is explored. Eddy transport processes occur mainly in boreal winter-spring when Cmlo-cgo is large; an important component is due to Rossby wave generation by the Himalayas and propagation through the equatorial Pacific westerly duct generating and transmitting turbulent kinetic energy. Mean transport occurs mainly in boreal summer-autumn and varies with the strength of the Hadley circulation. The timing of annual changes in Cmlo-cgo is found to coincide well with dynamical indices that we introduce to characterize the transports. During the unrivalled 2009–2010 step in Cmlo-cgo indices of eddy and mean transport reinforce. In contrast for the 2015 to 2016 change in Cmlo-cgo the mean transport counteracts the eddy transport and the record strength of the Hadley circulation determines the annual IH CO2 difference. The interaction of increasing global warming and extreme El Niños may have important implications for altering the balance between eddy and mean IH CO2 transfer.

scholarly journals Elevated CO2 Concentrations and Water Stress Affect the Ability of Italian Ryegrass to Remediate Herbicides and Enhance its Allelopathic Effect

2019 ◽  
Vol 37 ◽  
Author(s):  
L.P. SILVEIRA ◽  
A.R. FEIJÓ ◽  
C. BENETTI ◽  
J.P. REFATTI ◽  
M.V. FIPKE ◽  
...  
Keyword(s):  
Water Stress ◽  
Elevated Co2 ◽  
Co2 Concentration ◽  
Italian Ryegrass ◽  
Allelopathic Effect ◽  
Irrigated Rice ◽  
Allelopathic Potential ◽  
Co2 Concentrations ◽  
Temporal Persistence ◽  
The Impact

ABSTRACT: The long temporal persistence of select herbicides negatively impacts crops sown in succession to irrigated rice. One way to reduce these compounds in the soil over time is through phytoremediation. However, elevated CO2 concentrations may interfere with the phytoremediation process. Another consequence of climate change is the production of allelopathic compounds by forage species used as remedial agents. This study aimed to evaluate the impact of elevated CO2 concentration and drought stress on the remediation of soil samples contaminated with imazapyr + imazapic herbicides by Italian ryegrass and any subsequential affect on the allelopathic effect of this species. We report that the increasing CO2 decreased the phytoremediation potential of ryegrass. Water stress combined with a CO2 concentration of 700 µmol mol-1 caused increased allelopathy. Overall, these are the first data to indicate a significant effect of higher CO2 levels with respect to both phytoremediation efficacy and allelopathic potential of the plant species used in phytoremediation.

scholarly journals Effects of External Acidification on the Blood Acid-Base Status and Ion Concentrations of Lamprey

1988 ◽  
Vol 136 (1) ◽  
pp. 351-361
Author(s):  
LEONA MATTSOFF ◽  
MIKKO NIKINMAA
Keyword(s):  
High Sensitivity ◽  
Co2 Concentration ◽  
Acid Base ◽  
Ion Concentrations ◽  
Ph Response ◽  
Ph Values ◽  
Blood Ph ◽  
Acid Base Status ◽  
The Difference ◽  
K Concentration

We studied the effects of acute external acidification on the acid-base status and plasma and red cell ion concentrations of lampreys. Mortality was observed within 24 h at pH5 and especially at pH4. The main reason for the high sensitivity of lampreys to acid water appears to be the large drop in blood pH: 0.6 and 0.8 units after 24 h at pH5 and pH4, respectively. The drop of plasma pH is much larger than in teleost fishes exposed to similar pH values. The difference in the plasma pH response between lampreys and teleosts probably results from the low buffering capacity of lamprey blood, since red cells cannot participate in buffering extracellular acid loads. Acidification also caused a decrease in both Na+ and C− concentrations and an elevation in K+ concentration of plasma. The drop in plasma Na+ concentration occurred faster than the drop in plasma Cl− concentration which, in turn, coincided with the decrease in total CO2 concentration of the blood.

scholarly journals Effect of elevated carbon dioxide on biology and morphometric parameters of yellow stem borer, Scirpophaga incertulas infesting rice (Oryza sativa)

2022 ◽  
Vol 24 (1) ◽  
Author(s):  
GOURI SHANKAR GIRI ◽  
S. V. S. RAJU ◽  
S. D. MOHAPATRA ◽  
MUNMUN MOHAPATRA
Keyword(s):  
Carbon Dioxide ◽  
Larval Instar ◽  
Co2 Concentration ◽  
Elevated Carbon Dioxide ◽  
Stem Borer ◽  
Developmental Period ◽  
Morphometric Parameters ◽  
Scirpophaga Incertulas ◽  
Yellow Stem Borer ◽  
Co2 Concentrations

An experiment was conducted at Research Farm, National Rice Research Institute, Cuttack, Odisha, India to quantify the effect of elevated carbon dioxide (CO2) concentrations on the biology and morphometric parameters of yellow stem borer (Scirpophaga incertulas, Pyralidae, Lepidoptera). Yellow stem borer is one of the major pest of rice in the whole rice growing regions of South East Asia. The effect of three carbon dioxide concentrations i.e. 410 ppm (ambient), 550 ppm and 700 ppm on the duration of the developmental period as well as morphometric parameters of each stage of the lifecycle of the pest was analysed. It was found that, there was an increase in the duration of the developmental period of each stage of life cycle as the concentration of CO2 increases. However, the life span of the adult moth was significantly lower under the elevated CO2 concentrations when compared with ambient CO2 concentration. Morphometric parameters viz., mean length, width and weight of each larval instar, pupa and adult were found to be significantly higher in elevated concentrations of CO2 as compared to ambient concentration.

scholarly journals Konsentrasi Co2 Pada Ruang Kelas Dengan Sistem Ventilasi Alami, Tipe Jendela Gantung Atas

2018 ◽  
Vol 1 (1) ◽  
pp. 137-144
Author(s):  
Basaria Talarosha ◽  
Valencia Rosardy
Keyword(s):  
Natural Ventilation ◽  
Co2 Concentration ◽  
Learning Performance ◽  
Opening Angle ◽  
The Public ◽  
Public Elementary Schools ◽  
Co2 Concentrations ◽  
Size Number ◽  
Window Opening ◽  
The City

Proses pernafasan menghasilkan udara yang mengandung 4,4% volume CO2 sehingga konsentrasi CO2 di dalam ruang kelas dapat menjadi lebih tinggi dari ruang luar jika ventilasi tidak mencukupi. Konsentrasi CO2 > 1000 ppm akan mengganggu kesehatan dan konsentrasi belajar yang berdampak pada penurunan performa belajar siswa. Penelitian sebelumnya menunjukkan adanya hubungan antara konsentrasi CO2 di dalam ruang kelas dengan ukuran, jumlah, posisi dan tipe jendela pada ruang kelas yang menggunakan sistem ventilasi alami. Tipe jendela gantung atas disebutkan memiliki performa yang paling buruk dalam menetralkan konsentrasi CO2 di dalam ruang. Studi bermaksud mengukur kadar konsentrasi CO2 di dalam sebuah ruang kelas pada salah satu sekolah dasar negeri di kota Medan yang menggunakan tipe jendela gantung atas. Pengukuran konsentrasi CO2 dilakukan pada kondisi sudut bukaan jendela sisi koridor ruang kelas 10 dan 30 masing -masing selama tiga (3) hari. Hasil studi menunjukkan konsentrasi CO2 maksimum pada kondisi sudut bukaan jendela 10 lebih rendah dari pada kondisi sudut bukaan jendela 30LI, namun konsentrasi CO2 rata-rata pada kedua posisi jendela masih di bawah ambang batas konsentrasi CO2 yang diijinkan untuk kesehatan (<1000 ppm).   The breathing process produces air containing 4.4% of the volume of CO2 so that the concentration of CO2 in the classroom can be higher than the outside space if there is insufficient ventilation. CO2 concentration> 1000 ppm will interfere with the health and concentration of learning which has an impact on decreasing student learning performance. Previous research has shown a correlation between CO2 concentrations in classrooms with the size, number, position and type of windows in classrooms that use natural ventilation systems. The upper hanging window type is said to have the worst performance in neutralizing CO2 concentrations in space. The study intends to measure the level of CO2 concentration in a classroom in one of the public elementary schools in the city of Medan that uses a type of upper hanging window. Measurements of CO2 concentrations were carried out at the corridor opening angle of the class 10 and 30 for three (3) days, respectively. The results showed that the maximum CO2 concentration at the window opening angle 10 was lower than the 30LI window opening, but the average CO2 concentration in both window positions was still below the threshold of the permissible CO2 concentration for health (<1000 ppm).

scholarly journals The challenge of simulating warmth of the mid-Miocene Climate Optimum in CESM1

2013 ◽  
Vol 9 (3) ◽  
pp. 3489-3518 ◽  
Author(s):  
A. Goldner ◽  
N. Herold ◽  
M. Huber
Keyword(s):  
Temperature Gradient ◽  
Climate Models ◽  
Co2 Concentration ◽  
Mean Annual Temperature ◽  
Earth System ◽  
Equatorial Pacific Ocean ◽  
Proxy Records ◽  
Co2 Concentrations ◽  
Eastern Equatorial Pacific ◽  
Climatic Period

Abstract. The mid-Miocene Climatic Optimum (MMCO) is an intriguing climatic period due to its above-modern temperatures in mid-to-high latitudes in the presence of close-to-modern CO2 concentrations. We use the recently released Community Earth System Model (CESM1.0) with a slab ocean to simulate this warm period, incorporating recent Miocene CO2 reconstructions of 400 ppm. We simulate a global mean annual temperature (MAT) of 18 °C, ~4 °C above the pre-industrial value, but 4 °C colder than the global Miocene MAT we calculate from climate proxies. Sensitivity tests reveal that the inclusion of a reduced Antarctic ice sheet, eastern equatorial Pacific Ocean temperature anomalies, increased CO2 to 560 ppm, and variations in obliquity only marginally improve model-data agreement. All MMCO simulations have an equator to pole temperature gradient which is at least ~ 10 °C larger than the reconstruction from proxies. The MMCO simulation most comparable to the proxy records requires a CO2 concentration of 800 ppm. Our results illustrate that MMCO warmth is not reproducible using the CESM1.0 forced with CO2 concentrations reconstructed for the Miocene or including various proposed Earth system feedbacks; the remaining discrepancy in the MAT is comparable to that introduced by a CO2 doubling. The models tendency to underestimate proxy derived global MAT and overestimate the equator to pole temperature gradient suggests a major climate problem in the MMCO akin to those in the Eocene. Our results imply that this latest model, as with previous generations of climate models, is either not sensitive enough or additional forcings remain missing that explain half of the anomalous warmth and pronounced polar amplification of the MMCO.

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