The influence of African air pollution on regional and global tropospheric chemistry

International audienceWe investigate the relative importance of African biomass burning, biogenic volatile organic compounds (VOC), lightning and anthropogenic emissions to the tropospheric ozone budget over Africa and globally using a coupled global chemistry climate model. Our model studies indicate that the photochemical surface ozone concentration may rise by up to 50 ppbv in the burning region during the biomass burning seasons. Biogenic VOCs contribute between 5?20 ppbv to the near surface ozone concentration over the tropical African region. The impact of lightning on surface ozone is negligible, while anthropogenic emissions contribute a maximum of 10 ppbv to the surface ozone over Nigeria, South-Africa and Egypt. The annual average of the surface and column ozone over Africa shows that biomass burning is the single most important emission source affecting the African region, while biogenic emissions have the highest contribution during the rainy seasons. The contributions of African emissions to global tropospheric ozone burden (TOB) are about 9 Tg, 13 Tg, 8 Tg and 4 Tg for African biomass burning, biogenic VOC, lightning and anthropogenic emissions respectively. These correspond to 2.4%, 3.4%, 2.1% and 1% of the global tropospheric ozone budget respectively. Over Africa itself, the contribution of each of these emission types is only 2.4 Tg, 2.2 Tg, 1.4 Tg and 0.8 Tg respectively. Outside the continent, African biogenic VOC emissions yield the highest contribution to the TOB. Our model calculations suggest that about 70% of the tropospheric ozone produced from emissions in Africa is found outside the continent, thus exerting a noticeable influence on a large part of the tropical troposphere. Latin America experiences the highest impact of African emissions, followed by southeast and south-central Asia, Oceania, and the Middle East for all the emission categories; while Canada, the United States, Russia, Mongolia, China and Europe experience the least impact of African emissions

The vertical distribution of ozone instantaneous radiative forcing from satellite and chemistry climate models

We evaluate the instantaneous radiative forcing (IRF) of tropospheric ozone predicted by four state-of-the-art global chemistry climate models (AM2-Chem, CAM-Chem, ECHAM5-MOZ, and GISS-PUCCINI) against ozone distribution observed from the NASA Tropospheric Emission Spectrometer (TES) during August 2006. The IRF is computed through the application of an observationally constrained instantaneous radiative forcing kernels (IRFK) to the difference between TES and model-predicted ozone. The IRFK represent the sensitivity of outgoing longwave radiation to the vertical and spatial distribution of ozone under all-sky condition. Through this technique, we find total tropospheric IRF biases from -0.4 to + 0.7 W/m(2) over large regions within the tropics and midlatitudes, due to ozone differences over the region in the lower and middle troposphere, enhanced by persistent bias in the upper troposphere-lower stratospheric region. The zonal mean biases also range from -30 to + 50 mW/m(2) for the models. However, the ensemble mean total tropospheric IRF bias is less than 0.2 W/m(2) within the entire troposphere

Global Multi-Year O3-CO Correlation Patterns from Models and TES Satellite Observations

The correlation between measured tropospheric ozone (O3) and carbon monoxide (CO) has been used extensively in tropospheric chemistry studies to explore the photochemical characteristics of different regions and to evaluate the ability of models to capture these characteristics. Here, we present the first study that uses multi-year, global, vertically resolved, simultaneous and collocated O3 and CO satellite (Tropospheric Emission Spectrometer) measurements, to determine this correlation in the middle/lower free troposphere for two different seasons, and to evaluate two chemistry-climate models. We find results that are fairly robust across different years, altitudes and timescales considered, which indicates that the correlation maps presented here could be used in future model evaluations. The highest positive correlations (around 0.8) are found in the northern Pacific during summer, which is a common feature in the observations and the G-PUCCINI model. We make quantitative comparisons between the models using a single-figure metric (C), which we define as the correlation coefficient between the modeled and the observed O3-CO correlations for different regions of the globe. On a global scale, the G-PUCCINI model shows a good performance in the summer (C =0.71) and a satisfactory performance in the winter (C = 0.52). It captures midlatitude features very well, especially in the summer, whereas the performance in regions like South America or Central Africa is weaker. The UKCA model (C = 0.46/0.15 for July-August/December-January on a global scale) performs better in certain regions, such as the tropics in winter, and it captures some of the broad characteristics of summer extratropical correlations, but it systematically underestimates the O3-CO correlations over much of the globe. It is noteworthy that the correlations look very different in the two models, even though the ozone distributions are similar. This demonstrates that this technique provides a powerful global constraint for understanding modeled tropospheric chemical processes. We investigated the sources of the correlations by performing a series of sensitivity experiments. In these, the sign of the correlation is, in most cases, insensitive to removing different individual emissions, but its magnitude changes downwind of emission regions when applying such perturbations. Interestingly, we find that the O3-CO correlation does not solely reflect the strength of O3 photochemical production, as often assumed by earlier studies, but is more complicated and may reflect a mixture of different processes such as transport

COMPARING GEOSCIENCES-RELATED ENGAGEMENT GENERATED DURING AND AFTER THE USE OF MULTIPLE PEDAGOGICAL APPROACHES: ANIMATED VIDEOS, YOUTUBE, INTERACTIVE EDUCATIONAL GAMES, GROUP DISCUSSION AND POWERPOINT PRESENTATIONS

The COVID-19 pandemic has increased educators’ reliance on online learning tools such as Blackboard Collaborate Ultra and Zoom meetings to deliver geoscience-related lessons in real-time. Assessments were conducted using introduction to geology, environmental geology, and oceanography - part of the City University of New York\u27s (CUNY) newly implemented pathways curriculum. These general education courses belong to scientific world and life and physical sciences category and are intended for seamless transfer between CUNY campuses. Students, however, have the option to disengage from participation. Students are able to disable microphones and cameras, as well as rely entirely on text-chat if they choose. Students also have the option to simply log-on and not be physically present at all. If a practitioner does not advocate for forced participation via assigning a heavy weight of the course grade to participation, then the burden of bolstering engagement is almost entirely on the practitioner. This study attempts to review different pedagogical approaches and create a rubric to measure engagement during and after the delivery of the course contents. These approaches include short animated videos, long, medium, and short YouTube videos, interactive educational games, group discussions and debates, PowerPoint presentations, etc. The goal is to find approaches that deliver an effective learning, but still encourage organic class participation. Initial findings are as follows: short animated videos had the most total engagement with highly positively correlated with engagement during and after; long YouTube videos generated the most engagement during and after; single-player interactive educational games tied for highest total engagement and encouraged discussion during the game as well as after; short PowerPoint presentations with salient information did much better than longer presentations; and group discussions (when engaged upon) generated a moderate amount of total engagement. Trends included: length correlated positively with discussion during delivery, but negatively with discussion after delivery; intensity played no part in discussion during an activity, but correlated positively with discussion afterwards. In general, high intensity material of any kind, has been deemed the best

Influence of neighborhood environment and social support on physical activity among patients with diabetes mellitus

This study was aimed to determine the relationship of physical activity (PA) with the neighborhood environment and social support for PA among patients with diabetes mellitus (DM). A total of 193 consenting individuals with DM attending endocrinology clinic in a Nigerian tertiary hospital participated in this cross-sectional study. The international physical activity questionnaire short form, physical activity neighborhood environment scale (PANES), and physical activity and social support scale (PASSS) were used to assess the PA level (low, moderate, and high), neighborhood environment and social support for PA, respectively. The results of bivariate analyses showed that all elements of built environment and social support were significantly associated with PA. Regression model analyses indicate that PANES score was associated with moderate (adjusted odds ratio [aOR]: 10.76; 95% confidence interval [CI]: 3.82-30.32) to high (aOR: 45.73; 95% CI: 12.14-172.27) PA. In addition, easy access to quality walking facilities (aOR: 46.53; 95% CI: 3.89-557.32; aOR: 46.13; 95% CI: 2.65-802.40) and easy access to recreation infrastructure (aOR: 46.89; 95% CI: 3.95-487.83; aOR: 17.99; 95% CI: 1.28-252.98) were associated with moderate to high PA, respectively, while safety from crime (aOR: 0.21; 95% CI: 0.07-0.64) and easy access to services and shops (aOR: 21.90; 95% CI: 1.83-262.59) were associated with moderate and high PA. Informational social support was associated with moderate PA (aOR: 1.44; 95% CI: 1.04-2.00). In conclusion, the neighborhood environmental and social support factors were associated with the PA activity level among Nigerian patients with DM

Satellite constraint on the tropospheric ozone radiative effect

Tropospheric ozone directly affects the radiative balance of the Earth through interaction with shortwave and longwave radiation. Here we use measurements of tropospheric ozone from the Tropospheric Emission Spectrometer satellite instrument, together with chemical transport and radiative transfer models, to produce a first estimate of the stratospherically adjusted annual radiative effect (RE) of tropospheric ozone. We show that differences between modeled and observed ozone concentrations have little impact on the RE, indicating that our present-day tropospheric ozone RE estimate of 1.17 ± 0.03 W m−2 is robust. The RE normalized by column ozone decreased between the preindustrial and the present-day. Using a simulation with historical biomass burning and no anthropogenic emissions, we calculate a radiative forcing of 0.32 W m−2 for tropospheric ozone, within the current best estimate range. We propose a radiative kernel approach as an efficient and accurate tool for calculating ozone REs in simulations with similar ozone abundances

ADDRESSING THE LEARNING LOSS DURING THE COVID-19 PANDEMIC THROUGH THE ADAPTATION OF VIRTUAL PLATFORMS

The York College-hosted NASA MAA (MUREP AEROSPACE ACADEMY) has always played a pivotal role in minimizing the learning loss during the summer months, which was heightened during the pandemic. Support from AT&T, Con Edison and NASA enabled the MAA program at York College to offer a virtual STEM education with an earth science concentration to 1000 plus underserved K1-12 students from the community last summer, including 160 high school students. Two factors made this endeavor fruitful: allowing additional time to engage in STEM lessons and increasing self-motivation to successfully accomplish assigned tasks. Students built partnerships and resolved technical issues with the smaller class size. MAA students normally receive more than three hours of uninterrupted STEM lessons, as opposed to less than 90 minutes of instruction time in math and science classes in their respective public schools. Based on the successful outcome from the 2020 operation, York’s NASA MAA will be continuing its peer mentoring initiative, with the goal to increase the scope and allow additional students to receive both academic and research training during summer 2021, fall 2021 and spring 2022. Applied mathematics including analytical geometry, trigonometry, number theories, and algebra, as well as science and python-based programming lessons will be offered to students. The other notable pedagogical focus will be to provide meaningful connections with scientific vocabulary and how to communicate effectively. Group or individual presentations will be used in classroom activities. Modified and newly structured math and science curricula will enable participating students to fully engage in an interactive learning environment through discussion, breakout sessions, and homework. Individual math and science lessons are built on the best practices tailored down to the students\u27 reach and are aimed at fostering teamwork and group learning. Consequently, it is very important for the MAA summer program to continue to offer evidenced-based STEM education to minority students and allow them to become knowledgeable, well informed, and ready to apply for internships and attend college

POSITIVE OUTCOMES OF INVOLVING UNDERGRADUATE AND HIGH SCHOOL STUDENTS IN BROADER ASPECT OF EARTH SYSTEM SCIENCE THROUGH PEER MENTORING AND RESEARCH ACTIVITIES

The importance of involving undergraduates and high school students in field-and-laboratory research investigations at an early stage through peer mentoring has been clearly demonstrated as a critical tool for essential training to fully comprehend academic content and a deeper understanding of the various STEM, geoscience-and- environmental science related topics. As far as we are concerned, student presenters/participants (over 1000) in our topical sessions since 2004 have always found face-to-face presentation through poster sessions to be an ideal scientific venue where exchange of knowledge and discussion are fruitful, constructive and encouraging. It is quite revealing to note that among the student participants, 60% were female and they also dominated both undergraduate and high school populations! Student- led presentations at the GSA annual meeting (s) opened a plethora of academic gains, including appreciating the relevance of the topics presented, networking opportunities, preparation for graduate studies, and increasing self-esteem. Several student presenters, who have now completed their college education and are currently employed, have responded to us and said that their current employment experience is enhanced by the fact that our topical sessions primarily focused on the acquisition of experiential learning skills and provided them with career-oriented knowledge. It clearly supported our belief that research experience is vital to a well-rounded education and readiness for professional employment. We find this to be very useful in attracting urban students, particularly low-income and academically challenged students to pursue the geosciences since traditional classroom teaching alone cannot effectively create a sound pedagogical environment suitable to promote geoscience as a college option or as a career choice. It is becoming a routine practice in many City University of New York (CUNY) institutions, particularly York College, Virginia Commonwealth University, and city high schools to involve underrepresented students at an early stage and bring research opportunities to them through STEM research initiatives supported by MUREP Aerospace Academy - National Aeronautics and Space Administration (NASA), State Education Department, AT&T, Con Edison, National Grid, and National Science Foundation (NSF). Such collaboration ensures that the STEM/geosciences pipeline is constantly enriched in order to meet the future needs and challenges faced by society