- 1Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, Uttar Pradesh, India
- 2Department of Civil Engineering, Poornima University, Jaipur, Rajasthan, India
- 3Centre of Excellence in Water and Clean Air, Poornima University, Jaipur, Rajasthan, India
- 4DST-Mahamana Centre of Excellence in Climate Change Research, Banaras Hindu University, Varanasi, India
- 5Department of Remote Sensing, Birla Institute of Technology Mesra, Ranchi, India
This study aimed to identify the impact of an annular solar eclipse i.e., 21 June 2020 on the variation of meteorological parameters along with trace gases using statistical analyses. The study site is located at Poornima University, Jaipur (26.7796°N, 75.8771°E), Rajasthan, India. The observational analysis indicates a rapid decrease in solar direct radiation (SDR) which varied between 706 and 79 W/m2 during the eclipse. SDR was reduced to 79 W/m2 at the maximum peak of the solar eclipse at 11:55 a.m. at the study location. The comparative analysis shows the variation of SDR during the solar eclipse day, the previous day, and the day after the event. A strong dip was observed in SDR during the annular eclipse day concerning before (734.31 W/m2) and after (734.375 W/m2) eclipse event. Furthermore, the impact of the solar eclipse on temperature (Ts) and Relative Humidity (RH) was analyzed over Jaipur. The statistical analyses demonstrate an apparent decrease in temperature of about 2°C while RH shows a slight increment (3.45%) during the solar eclipse event. The results show an inverse correlation between the solar eclipse and trace gases variations during the eclipse due to the changes in solar radiation, surface temperature, and variation in winds that might affect the photochemical processes.
Introduction
The solar eclipse is a rare natural phenomenon, which provides a unique opportunity to study the sudden changes in the atmosphere due to variation in solar direct radiation (SDR) (Tzanis et al., 2008). SDR plays a very important role in shaping the Earth’s thermal balance. Solar eclipse leads to rapid cut-off in SDR for a duration of a few minutes to hours and has the ability to alter the Earth’s Energy Budget. Abbott (1958) measured the radiative changes during the partial eclipse and reported that a small reduction in net SDR was much greater than the small obscuration of the Sun’s disc and stated that the phenomenal decrease was due to penumbra in the atmosphere. The variation in the SDR is responsible for the abrupt changes in meteorological variables and photochemical processes in the atmosphere. A large number of studies carried out to understand the impact of the solar eclipse on the atmospheric phenomenon. The impact of the solar eclipse on meteorological variables i.e., RH, solar radiation, temperature, wind speed, wind direction, and precursor gases is quantified by many researchers (Srivastava et al., 1982; Fernadez et al., 1993a; Abram et al., 2000; Fabian et al., 2001; Zanis et al., 2001; Zerefos et al., 2001; Kolev et al., 2005; Tzanis, 2005; Zerefos et al., 2007; Gerasopoulos et al., 2008; Sharma et al., 2010a). The variation in RH and Ts occurs during a solar eclipse. The drop and rise in meteorological parameters are different for each location due to the percentage of Sun coverage, time of the day, latitude, synoptic condition, etc. during the solar eclipse. The change in surface temperature is one of the most noticeable meteorological parameters experienced by the observer. Generally, when the Sun is half covered the temperature drop becomes noticeable (Anderson, 1999), while other observers reported the immediate temperature response after the start of the solar eclipse (Anderson, 1972; Szalowski, 2002). In contrast, the RH shows the opposite signature during a solar eclipse. The minimum temperature found during a solar eclipse when the Sun is maximum covered by a celestial body.
The solar ultraviolet radiation at 312 and 365 nm showed a reduction of 3% and 7%, respectively at four stations in the greater Athens basin in Greece (Founda et al., 2007) during a solar eclipse. The air temperature dropped to ∼0.7°C while RH increased and was found to be maximum at the end of the eclipse at the center of Athens. Jain et al., 2020 studied the impact of the solar eclipse on meteorological parameters and trace gases over Gadanki and reported that the Global Horizontal irradiance (GHI) decreased ∼95.5% during the eclipse and was responsible for a temperature decrease of 4.36°C, sustained 100% RH and delayed atmospheric boundary layer development. The concentration of O3 decreases up to 48% whereas NO2 concentration has been increased by ∼8 times. There has been a time lag (∼52 min) in observing the effects which are generally attributed to the production and destruction mechanisms of these species and the meteorological parameters of the observation site. Similarly, the reduction in wind speed and ambient temperature was recorded at Thiruvanathapuram, India during a nearly total eclipse on 15 January 2010, whereas RH experienced the increment (Sharma et al., 2010a).
This is the first study of its kind on annular solar eclipse over Jaipur in the vicinity of the Thar Desert to understand the effect of eclipse on meteorological parameters and trace gases. In the current work, an investigation has been conducted to understand the impact of the solar eclipse that occurred on 21 June 2020, on meteorological variables i.e., RH, Ts, SDR, wind speed (WS), etc. and trace gases i.e., O3, NH3, NOx, and NO over Jaipur, Northwestern India. The study further compares these parameters with pre- and post-annular solar eclipse event.
Observation site and solar eclipse
This solar eclipse study was conducted at Poornima University, Jaipur (26.7796°N, 75.8771°E). Jaipur is located in the vicinity of the Thar Desert. Jaipur experiences a semi-arid climate with an average rainfall of ∼60 cm (Verma et al., 2013). Jaipur is the capital of Rajasthan, the largest state of India. Jaipur has a very rich traditional culture and is known as Pink City (Prakash et al., 2013). Jaipur is a colorful city with an oscillation of organized architecture unveiling the royal culture, arts, and traditions as the heritage of Rajasthan.
The first solar eclipse of 2020 occurred on 21st June over Jaipur, Rajasthan (Figure 1). This annular solar eclipse started in Afric h and 45 min with start at the eastern part of the Democratic Republic of Congo at 4.48 GMT just at sunrise and ended in the Pacific Ocean at 8.32 GMT (Pratap et al., 2021). This eclipse is unique in a manner as it took place on June solstice (21st June i.e., the day which brings the longest day of the year). The maximum obscuration over Jaipur has been 88.1% (the eclipse intensity has been expressed in obscuration rather than phases because this has been a partial solar eclipse over Jaipur) with a maximum magnitude of 0.88 at around 11:56 IST (06:26 GMT). The total eclipse period observed at Jaipur has been about 3 h and 29 min starting at 10:14 IST (Indian Standard Time or 04:44 UTC) and ending at 13:44 IST (8:14 GMT).
Methodology
For this study, an Automatic Weather Station (AWS) is installed on the rooftop of the Academic Block of Poornima University, Jaipur. The changes in meteorological parameters were recorded by the Automatic Weather Station (WatchDog 2900 ET Weather Station) manufactured by Spectrum Technologies, Aurora, IL, United States) during the Solar eclipse. The accuracy of WatchDog Sensor for Ts, RH, WS, wind direction, SDR, and Dew point is ± 0.6°C, ±3%, ± 3 km/h or ± 5%, whichever is greater; ± 4°, ± 5%, and ± 2°C, respectively. The meteorological parameters were recorded with a 1-min temporal resolution during the solar eclipse.
The trace gases observations were collected by the Continuous Ambient Air Quality Monitoring Stations (CAAQMS) under the national air quality monitoring network at Police Commissionerate Jaipur (26.916, 75.801) and this monitoring site is maintained by Rajasthan State Pollution Control Board (RSPCB), Jaipur. All the trace gases data set used in the present study is freely available at the website of the Central pollution control board (CPCB): https://app.cpcbccr.com/ccr/#/caaqm-dashboard-all/caaqm-landing/data. CPCB has deployed different types of instruments fitted with sensors certified by world meteorological organization to collect data (CAAQMS Guidelines, 2019). The monitors are reported to be regularly calibrated by operating bodies by the instruction manual of the equipment for ensuring the quality of the data.
Results and discussion
The solar eclipse of 21 June 2020, at Jaipur, northwestern India, started at 10:14 a.m. (IST) and ends at 01:44 p.m. (IST) with maximum solar coverage (88.1%) at 11:55 a.m. (IST) over the observation site. This solar eclipse occurred more than 3 h over Jaipur. The changes in meteorological parameters and trace gases during a solar eclipse are discussed in this section.
1) Impact of the annular solar eclipse on Solar Radiation
Figure 2 shows the temporal variation of SDR during the eclipse at Jaipur. The value of SDR varies between 706 and 79 W/m2 during the eclipse. As the percentage of Sun’s covered area started to increase, SDR started to decrease. For the maximum Sun coverage (88.1%), the SDR was reduced to 79 W/m2 at the maximum peak of the solar eclipse at 11:55 a.m. The SDR’s comparative analysis is also done a day before and after the solar eclipse. Figure 3 shows the variation of SDR during the solar eclipse and the day before and after the event. A strong dip was observed in average SDR during annular eclipse day (384.16 W/m2) concerning previous (400.81 W/m2) and after day (406.45 W/m2) of the event (Figure 3).
FIGURE 3. Temporal variations (6 AM to 7 PM) of SDR during the solar eclipse, a day before and a day after the event.
The statistical analysis of the observed value was carried out to understand variation in SDR with Ts and RH as shown in Table 1. From Table 1, it can be seen that the maximum and average SDR during solar eclipse day is found to be low than on other days during study period.
2) Meteorological parameters during an annular solar eclipse
The meteorological parameters play the important role in any natural phenomenon. The Temperature (Ts) and Relative humidity (RH) are the important meteorological parameters to understand the synoptic meteorology of any location. The variation in temperature and RH was also observed during the solar eclipse event. Jaipur experiences a hot temperature with less humidity during the summer season. The highest temperature in Jaipur reaches more than 45°C in the summer season.
The impact of the solar eclipse on temperature and RH was quantified over Jaipur and it is found that the temperature decreases about 2°C while RH shows a slight increment during the solar eclipse event (Figure 4).
Figure 5 shows the temporal variation of temperature during the event, a day before, and a day after. The temperature before the start of the event was higher than the day before and the day after but during an eclipse, the temperature dropped (−2°C) due to less availability of SDR.
FIGURE 5. Temporal variations (6 a.m.–7 p.m.) of temperature during a solar eclipse, a day before and a day after at Jaipur.
The variation in wind speed was also observed during the solar eclipse and the average WS was found higher (78%) during the event than on previous as well as upcoming days (Figure 6). The wind speed did not show any specific trend during the solar eclipse. The previous studies reported a decrease in WS (e.g., Clayton et al., 1901; Anderson and Keefer, 1975; Fernandez et al., 1993b).
FIGURE 6. Temporal variations of wind speed during a solar eclipse, a day before and a day after at Jaipur.
The wind direction was found mostly southwesterly during the annular solar eclipse (Figure 7).
3) Impact of the solar eclipse on Trace Gases
The concentration of trace gases plays important role to understand its adverse impact on human health. Concentration of ground Ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. Similarly, the Nitrogen Oxides also gives the adverse effect to human health, it may cause brief, nonspecific symptoms such as cough, shortness of breath, tiredness, and nausea. The high concentration of Ammonia causes immediate burning of the eyes, nose, throat and respiratory tract and can result in blindness, lung damage or death.
Previous studies also reported the changes in surface temperature, variation in winds, boundary layer height, and photochemical processes during the eclipse event over India (Naja and Lal, 1997; Sharma et al., 2010b; Venkat Ratnam et al., 2010; Girach et al., 2012; Girach et al., 2020; Jain et al., 2020). They have reported substantial variations in the surface level concentrations of the photochemical species such as O3 and NOx which have a direct linkage to solar irradiation.
The concentration of trace gases i.e., O3, NH3, NOx, and NO shows the high variability during the solar eclipse at Jaipur (Figure 8). Ozone (O3) is a secondary pollutant that forms in the presence of sunlight and its precursors viz, nitrogen oxides (NOx), and volatile organic compounds (Yadav et al., 2016; Yadav et al., 2020). Its concentration depends on photochemistry, physical/chemical removal, and transport over local, regional, and global scales (Lal et al., 2000). The concentration of O3, NO, NOX, and NH3 over Jaipur varies between 38.65–54.17 μg/m3; 5.33–7.54 μg/m3; 17.16–22.35 μg/m3; 26.12–32.37 μg/m3, respectively. The lowest concentration of NO and NOX is found at the maximum Sun obscuration during a solar eclipse. The concentration of O3 and NH3 shows contradictory behavior during the solar eclipse.
O3 concentration decreased by 23% during the solar eclipse day than the previous day (Figure 9). Even after more ozone formation due to the availability of more solar radiation on post-solar eclipse days, it is not visible in Figure 9 due to the non-availability of data. A similar trend in ozone concentration at Gadanki (Jain et al., 2020) and Yunnan province (Tian et al., 2022) during a solar eclipse. O3 has shown a reduction in its concentration by up to 48% during solar eclipse days at Gadanki (Jain et al., 2020) and about 40% at Yunnan province (Tian et al., 2022). Similarly, the concentration of NO, NOX, and NH3 also decreased by 4.08%, 8.16%, and 7.19%, respectively during the solar eclipse day than the previous day. The concentration of NH3 was also compared during the event. The concentration of NH3 found low during solar eclipse days than pre and post-event.
FIGURE 9. Comparison of ozone concentration during solar eclipse, a day before and a day after the event.
Conclusion
The annular solar eclipse of 21 June 2020 brought the opportunity of studying changes in meteorological parameters and comparing them with a day before and a day after meteorological parameters. The value of SDR decreased from 706 and 79 W/m2 during the eclipse. The temperature dropped to about 2°C during the solar eclipse due to less SDR reaching to the surface. As the temperature decreases, a slight increment was observed in RH. The wind speed also decreased due to a stable atmosphere during the solar eclipse. The concentration of trace gases also shows variability with about 23% deduction in O3 during a solar eclipse.
Data availability statement
The raw data supporting the conclusion of this article will be made available by the authors, without undue reservation.
Author contributions
DP: Conceptualization, Writing—original draft. SV: Supervision, Methodology, Writing—review and editing. SP: Visualization, Writing—review and editing. VK: Validation, Data curation.
Acknowledgments
Author DP is thankful to the management of Poornima University, Jaipur for providing the research facilities to carry out this work. Author DP is also thankful to Mr. Dinesh Jangid for maintaining the Automatic Weather Station. We are very much thankful to Rajasthan State Pollution Control Board (RSPCB) and Central Pollution Control Board (CPCB), India for the availability of trace gases data.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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Keywords: solar eclipse, solar radiation, Temperature, energy budget, trace gases, Northwestern India
Citation: Prakash D, Verma S, Payra S and Kumar V (2022) Impact of an annular solar eclipse on trace gases and meteorological parameters over Jaipur, Northwestern India. Front. Environ. Sci. 10:1005888. doi: 10.3389/fenvs.2022.1005888
Received: 28 July 2022; Accepted: 20 September 2022;
Published: 06 October 2022.
Edited by:
Ravi Yadav, Indian Institute of Tropical Meteorology (IITM), IndiaReviewed by:
M. P. Raju, India Meteorological Department, IndiaAtinderpal Singh, University of Delhi, India
Copyright © 2022 Prakash, Verma, Payra and Kumar. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Divya Prakash, divyaprakashyadav@gmail.com; Swagata Payra, spayra@gmail.com