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On 8 April 2024, a rare total solar eclipse (TSE) passed over western New York State (NYS), the first since 1925 and the last one until 2079. The NYS Mesonet (NYSM) consisting of 126 weather stations with 55 on the totality path provides unprecedented surface, profile, and flux data and camera images during the TSE. Here we use NYSM observations to characterize the TSE's impacts at the surface, in the planetary boundary layer (PBL), and on surface fluxes and CO2 concentrations. The TSE‐induced peak surface cooling occurs 17 min after the totality and is 2.8°C on average with a maximum of 6.8°C. It results in night‐like surface inversion, calm winds, and reduced vertical motion and mixing, leading to the shallowing of the PBL and its moistening. Surface sensible, latent and ground heat fluxes all decrease whereas near‐surface CO2 concentration rises as photosynthesis slows down. Plain Language Summary: On 8 April 2024, a rare total solar eclipse (TSE) passed over western New York State (NYS), the first one since 1925 and the last one until 2079. The entire NYS witnessed at least 88% obscuration at the peak of the eclipse. It provides an excellent opportunity to study the impacts of the TSE. The NYS Mesonet (NYSM), an advanced statewide weather network, has 55 stations on the totality path and provides unprecedented measurements of surface meteorological variables, atmospheric vertical profiles, the heat exchange between the atmosphere and the surface and carbon dioxide (CO2) concentration. It enables one to study the TSE in greater details on a regional scale for the first time. This study found that the moon shadow cools the surface by as much as 6.8°C and creates a surface inversion layer. The cooling calms down winds and vertical mixing, leading to less escape of the water vapor and moistening of the air. It also reduces the heat exchange between the surface and the air. Without sunlight, the photosynthesis shuts down, causing a robust rise in near‐surface CO2 concentration. One‐minute camera images provide a fantastic view of the darkening of the sky during the TSE. Key Points: The New York State Mesonet provided unprecedented surface, profile, flux and image data during the 8 April 2024 total solar eclipse across New York StateThe eclipse resulted in significant cooling and moistening near the surface and in the boundary layer, leading to a surface inversion layerIt also weakened surface winds, turbulent mixing, heat fluxes, but caused a robust rise in near‐surface CO2 concentrations [ABSTRACT FROM AUTHOR]

A total solar eclipse provides an unparalleled opportunity to study the changes in the atmosphere's planetary boundary layer (PBL) due to changes in radiative heating. Although previous eclipse studies have demonstrated that significant changes occur, few studies have explored the evolution of these changes. To better understand the changes in the lowest layers of the PBL during an eclipse, a multi-sensor sampling approach was taken. Radiosonde launches were used to explore the depth of the column, while Unmanned Aerial Vehicles (UAVs) were used to document with high-resolution the brief changes in the vertical structure of the PBL caused by the eclipse. These changes highlighted differences from previous studies that relied solely on radiosonde and/or mesonet data alone. Higher-resolution sampling of the lower PBL showed a delay in the local vertical mixing as well as changes in the PBL height from pre- to post-eclipse. Slow responses were noted at the top of the PBL while very rapid changes to the PBL profile were captured in the near-surface layer. These changes highlighted differences from previous studies that relied solely on radiosonde and/or mesonet data alone. A preliminary analysis of the collected data highlighted a slow response to the eclipse near the top of the planetary boundary layer (radiosonde data) with very rapid changes noted in the near surface layer (UAV data). Preliminary results show that PBL heights remained nearly constant until well after third contact when a 35 hPa lowering of the PBL heights was observed and were limited to the lowest 25 hPa. The UAV soundings demonstrated the development of a strong inversion where the air below 990 hPa rapidly cooled with a nearly 1 °C drop in temperature observed. These observed changes raise interesting questions about how the lower and upper parts of the planetary boundary layer interact. [ABSTRACT FROM AUTHOR]

Copyright of Clio: Revista de Pesquisa Histórica (01024736) is the property of Universidad Federal de Pernambuco / Revista Clio and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A total solar eclipse was recorded in a classic Chinese book with the title The Travels of an Alchemist: the Journey of the Taoist Ch'ang Ch'un from China to the Hindukush at the Sumons of Chingiz Khan. In the present paper, possible locations of the solar eclipse observation are investigated, taking into account the geographical characteristics of local environments. With a modern astronomical planetary ephemeris, the authors confirm the observation records and derive an upper limit of +768 seconds for the Δ T value at the epoch A.D. 1221. [ABSTRACT FROM AUTHOR]

The total solar eclipse of 21 August 2017 was unique in that the path of totality swept across the high spatial and temporal resolution QuantumWeather® mesonet and was very near the city of St. Louis Missouri. Thus, the meteorological response to the eclipse was complicated by the St. Louis urban heat island. Temperature changes of up 4 °C were observed across the network. Composite meteograms for rural, suburban, and urban stations displayed significant differences in the observed temperature and pressure response to the eclipse with a peak amplitude at the time of the eclipse. The differing response suggests that the urban heat island and changes in land surface characteristics alter the temperature and pressure response by the passage of the eclipse shadow. Oscillations in the composite meteograms appear to be the consequence of the passage of an outflow boundary across the network. As the outflow boundary moves north to south, the outflow boundary manifests its presence in the pressure field as a damped oscillation. Sounding data were collected along the center line of eclipse and along the southern edge of the eclipse before and during the eclipse. The soundings show that the eclipse altered the boundary layer height, the lowest layer of the atmosphere, in an unexpected way. [ABSTRACT FROM AUTHOR]

The results obtained during the total Solar Eclipse on July 2, 2019, in Chile are presented together with the Eclipse K-corona Polarimeter (EKPol). The EKPol is equipped with an electro-optically modulating Liquid-Crystal Variable Retarder (LCVR) for the polarimetric observation of the solar corona. The use of this technology has been an important ground-based test for the application of this technology in space-based observatories. The usage of LCVRs in a polarization rotator configuration allows the replacement of mechanically rotating retarders avoiding moving parts and reducing noise, failure probability, and mass. Indeed, EKPol was developed as a technology demonstrator for the Metis coronagraph on-board Solar Orbiter. The results, from the composition of the image to the electron density map evaluation, are compared and are consistent with what is obtained by other ground- and space-based instruments, and with past EKPol campaigns. [ABSTRACT FROM AUTHOR]

A total solar eclipse occurred at the ascending node of the Moon's orbit on 2 July 2019, with an eclipse magnitude of 1.0459. The totality was visible from the southern Pacific Ocean east of New Zealand to the Coquimbo Region (Chile) and Central Argentina at sunset, with the maximum of 4 min 32 s visible from the Pacific Ocean. The recent Great American Eclipse, 21 August 2017, clearly showed that the ionosphere is strongly affected by the totality. In order to explore the ionospheric signature of the 2019 eclipse, we use data of ∼110 GNSS stations seeing multiple GPS and GLONASS satellites to visualize the eclipse signature on the total electron content (TEC) in the southern hemisphere. The location of the South American GNSS stations, at the end of the path of totality, right before sunset, makes the eclipse signature in the ionospheric TEC act like an early sunset with 15 TEC‐Unit variations, corresponding to 40% of background ionization. The effect reaches only four TEC‐Units, corresponding to 25%–40% of background ionization, for the more westerly observations, where we clearly highlight the effect of the eclipse in the ionosphere and the following recovery to normality. By applying the omega‐k analysis, we can find TIDs with wavelengths of around 100 km and larger than 200 km and with periods of 20–50 min, which supports the results of the Great American Eclipse. Using different grids, we can also prove the robustness of the omega‐k analysis. Plain Language Summary: A total solar eclipse occurred on 2 July 2019 over the Pacific Ocean and South America with the eclipse shadow reaching the eastern coast of South America near Buenos Aires around sunset. We calculate the differential total electron content (TEC) to visualize the evolution of the phenomena with high spatial and temporal resolution. The effect of the eclipse in the ionosphere is clearly visible and appears as TEC depletion, which for some stations of central and eastern South America looks just like an early sunset. The omega‐k analysis confirms the results of the Great American Eclipse regarding wavelength and period of the TIDs induced by the shadow of the Moon. Using different grids, we proved the robustness of the omega‐k analysis. The effect of the solar eclipses in the southern hemisphere is coherent with the observations in the northern hemisphere even if we do not recognize the presence of bow waves. Key Points: GNSS observations of solar eclipse show total electron content (TEC) depletionsWe observe TIDs of >200‐km wavelength that are related to the TEC depletion due to the Moon's shadowTotal solar eclipse proves robustness of the omega‐k analysis [ABSTRACT FROM AUTHOR]

The Southern Andes, in Patagonia, are a well‐known hotspot of orographic gravity waves (oGWs) during winter when atmospheric conditions, such as temperature, wind speed, and wind direction, favor their generation and propagation. In the summer, oGWs above the mesosphere and oGW‐induced ionospheric perturbations are rarely observed because vertical wave propagation conditions are unfavorable. Nevertheless, when atmospheric conditions deviate significantly from those typical of summer, for example, during a solar eclipse (SE), the atmospheric temperature and wind changes can allow oGWs to reach ionospheric heights. Global Navigation Satellite Systems (GNSS)‐based ionospheric total electron content (TEC) studies of the 2017 North American eclipse showed oGW‐compatible observations near the totality zone around the Rocky Mountains, and it was suggested, but not shown, that these were likely oGWs. In this work, we report, model, and interpret GNSS TEC perturbations observed during the December 14, 2020 total SE in South America. TEC data recorded near the Andes during this total SE are in good agreement with predictions by the SAMI3 ionospheric model until shortly after the passage of the umbra. TEC data after totality can best be explained with the interpretation that the observation of oGWs was favored by the passage of the eclipse over the Andes Mountains. Key Points: A physics‐based model can be used together with detrending techniques to identify wave‐induced total electron content perturbationsAtmospheric gravity waves were detected using virtual array beamforming over the Andes during the 2020 total solar eclipse in South AmericaThe eclipse appears to have favored the vertical propagation of orographic gravity waves into the thermosphere [ABSTRACT FROM AUTHOR]

A total solar eclipse affected southern South America on December 14, 2020. Its occurrence close to the summer solstice in the Southern Hemisphere and around noon brought almost ideal conditions to study the effects of the sudden reduction in incoming solar radiation on different atmospheric variables. Interestingly, the astronomical phenomenon moved over a region that at that time was being affected by a cold front accompanied by significant cloudiness and cold air advection to the area. Therefore, the actual drop in surface temperature over the umbra region resulted from a combination of the radiative effect (i.e., the reduction in solar radiation due to the eclipse itself) and a circulation effect related to the injection of colder air. A quantification of both effects on the full temperature variation is provided, along with a discussion on the underlying mechanisms and the related effects on surface winds derived from the cooling. Results show that temperature drops associated with total solar eclipses in areas far away from the umbra can be as high as (or even higher than) those within the umbra, depending on the prevailing weather conditions. [ABSTRACT FROM AUTHOR]

The total solar eclipse (TSE) in Indonesia during the first quarter of 2016 was a very popular event in the Southeast Asia region and became a popular topic for both traditional and new media. Many digital media outlets had live coverage on this event. For the astronomy website langitselatan, a new media website, preparation for this event began in 2015. In this instance we used our available channels, which included interactive social media platforms, to share information regarding the 2016 TSE. We used a special domain, gerhana.info, to cover everything about this particular eclipse. This article explores our strategy in utilising new media for astronomy communications using gerhana.info as a case study and its impact up to the day of the eclipse. We also explore the impact on people's awareness of astronomy topics and events after the TSE via our main website langitselatan. [ABSTRACT FROM AUTHOR]

The total solar eclipse of 21 August 2017 traversed ~5000 km from coast to coast of North America. In its 90-min span, sunlight dropped by three orders of magnitude and temperature by 10–15°C. To investigate impacts of these changes on bee (Hymenoptera: Apoidea) pollinators, we monitored their flights acoustically in natural habitats of Pacific Coast, Rocky Mountain, and Midwest regions. Temperature changes during the eclipse had little impact on bee activity. Most of the explained variation (R 2) in buzzing rate was attributable to changes in light intensity. Bees ceased flying during complete darkness at totality, but flight activity was unaffected by dim light in partial phases before and after totality. Flights of bees during partial phases of the eclipse lasted longer than flights made under full sun, showing that behavioral plasticity matched bee flight properties to changes in light intensity during the eclipse. Efforts of citizen scientists, including hundreds of school children, contributed to the scope and educational impact of this study. [ABSTRACT FROM AUTHOR]

We present D region ionospheric response to 22 July 2009 total solar eclipse by modeling 19.8‐kHz signal from NWC very low frequency (VLF) navigational transmitter located in the Australia. NWC VLF signal was received at five stations located in and around eclipse totality path in the Indian, East Asian, and Pacific regions. NWC signal great circle paths to five stations are unique having eclipse coverage from no eclipse to partiality to totality regions, and the signal is exclusively confined in the low and equatorial regions. Eclipse‐induced modulations in NWC signal have been modeled by using long‐wave propagation capability code to obtain D region parameters of reflection height (H′) and sharpness factor (β). Long‐wave propagation capability modeling showed an increase in H′ of about 2.3 km near central line of totality, 3.0 km in the region near to totality fringe, and 2.4 to 3.0 km in the region under partial eclipse. Using H′ and β, Wait ionosphere electron density (Ne) profile at the daytime altitude of 75 km showed a decrease in Ne by about 58% at a station near totality central line, whereas at totality fringe and in partial eclipse region decrease in the Ne was between 63% and 71% with respect to normal time values. The eclipse associated variations in the H′, β, and Ne are less in low‐latitude region as compared to midlatitude. The study contributes to explain observations of wave‐like signature in the D region during an eclipse and difference in the eclipse effect in the different latitude‐longitude sectors. Plain Language Summary: The work was taken up in light of recent 21 August 2017 great American total solar eclipse. An eclipse in magnitude larger than American eclipse happened on 22 July 2009 in Asia and Pacific region. We revisited our acquired very low frequency data to understand its effect on the ionized part of our upper space environment ionosphere, in low‐latitude region as 22 July 2009 eclipse happened in low‐latitude region. We performed long‐wave propagation capability modeling on the observed very low frequency transmission and compared results with the great total eclipse in midlatitude to high‐latitude regions. The results are unique and new and show that total eclipses have varied effect on D region ionosphere in different latitude‐longitude sectors of the globe. The unique results obtained show that for an eclipse in low latitudes, the variations in H′ and β are more and D region Ne reduction is less, when compared with eclipse in midlatitude region. Study contributes to explain observations of wave‐like signature in ionosphere during eclipse and difference in eclipse effect on ionosphere in different latitude‐longitude sector. Key Points: The decrease in NWC signal amplitude was observed at all five stations associated with 22 July 2009 total solar eclipseLWPC modeling showed an increase in the D region reflection height of about 2.3‐3.0 km at stations under varying eclipse conditionsThe decrease in electron density varied from 58% to 71% in the region from near central line of totality to region on the fringe of totality [ABSTRACT FROM AUTHOR]

Abstract: A moon shadow of the total solar eclipse swept through the continent of United States (CONUS) from west to east on 21 August 2017. Massive total electron content (integration of electron density from 0 km to 20,200 km altitude) observations from 2,255 ground‐based Global Navigation Satellite System receivers show that the moon shadow ship generates a great ionospheric bow wave front which extends ~1,500 km away from the totality path covering the entire CONUS. The bow wave front consists of the acoustic shock wave due to the supersonic/near‐supersonic moon shadow ship and the significant plasma recombination due to the reduction in solar irradiation within the shadow area. The deep bow wave trough (−0.02 total electron content unit (1 TECU = 1016 el m−2) area) nearly coincides with the 100% obscuration moving along the totality path over the CONUS through the entire eclipse period. The supersonic moon shadow ship induces a bow wave crest in front of the ship (~80% obscuration). It is the first time to find the acoustic shock wave‐formed bow wave trough and crest near the totality. [ABSTRACT FROM AUTHOR]

The behaviour of remotely sensed land surface temperatures (LSTs) from the spinning-enhanced visible and infrared imager (SEVIRI) during the total solar eclipse of 20 March 2015 is analysed over Europe. LST is found to drop by up to several degrees Celcius during the eclipse, with the minimum LST occurring just after the eclipse mid-point (median= +1.5 min). The drop in LST is typically larger than the drop in near-surface air temperatures reported elsewhere, and correlates with solar obscuration (r= -0.47; larger obscuration = larger LST drop), eclipse duration (r=-0.62; longer duration = larger LST drop) and time (r=+0.37; earlier eclipse = larger LST drop). Locally, the LST drop is also correlated with vegetation (up to r=+0.6), with smaller LST drops occurring over more vegetated surfaces. The LSTs at locations near the coast and at higher elevation are also less affected by the eclipse. This study covers the largest area and uses the most observations of eclipse-induced surface temperature drops to date, and is the first full characterization of satellite LST during an eclipse (known to the author). The methods described could be applied to Geostationary Operational Environmental Satellite (GOES) LST data over North America during the August 2017 total solar eclipse. [ABSTRACT FROM AUTHOR]

During the total solar eclipse on July 22, 2009 in Wuhan, the joint observation test of Na layer and ionosphere was conducted by using the daytime observation atmospheric lidar and the GPS ionosphere detector. The results show that the full width at half maximum (FWHM) of Na layer density slightly narrowed during the total solar eclipse and broadened after the eclipse, while the height of Na peak slightly decreased in the eclipse and increased after the eclipse. These implying that Na layer changes reflect the rapid process of sunrise and sunset. The ionosphere total electron content (TEC) and the sky background light noise also presented an obvious fluctuation characteristic with the changes of solar irradiation during the process of total solar eclipse. The difference lies in that the changes of FWHM of Na layer atoms are much slower than that of ionosphere, the reason for this might be that the Na layer, after being disturbed by the total solar eclipse, will generate a series of complicated photochemical reactions and momentum transport processes, and then recombine the Na atoms. The Na atoms to be detected by the lidar need a lag process, which rightly conforms to the theoretical simulated results. [ABSTRACT FROM AUTHOR]

Based on observations of polar plume kinematics in the white-light corona during the total solar eclipse in 2006, the images obtained during multi-station observation of the eclipses of 2006, 2008, 2009 and 2010 were analysed. Several polar plumes showing similar kinematics were identified. The speeds of these dynamic features were found by comparing images obtained at different times along the path of totality. A possible connection with erupting spicules and macrospicules is discussed. [ABSTRACT FROM AUTHOR]

Copyright of Turkish Journal of Earth Sciences is the property of Scientific and Technical Research Council of Turkey and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Geomagnetic measurements during the total solar eclipse of August 1, 2008 in Novosibirsk (Klyuchi Observatory, NVS) and at the Burmistrovo station located on the total eclipse axis revealed eclipse-induced changes against the background of the normal daily variation. The main changes are a decrease in the X (north) component and an increase in the inclination I. Similar changes were recorded at the LZH observatory in China. Analysis of data on the eclipse of August 11, 1999 in Europe failed to unambiguously reveal eclipse effects against intense variations of ionospheric origin which occurred at the same universal time (UT). The geomagnetic effect of the solar eclipse may be due to a decrease in the electron concentration in the ionosphere and the corresponding decrease in the ionospheric current density. [Copyright &y& Elsevier]

The development of solar physics is presented from the program of 2008 total eclipse in China, including the presentations in the international workshop in this period and some observational results of the solar eclipse. [ABSTRACT FROM AUTHOR]

During the 2008 total solar eclipse, the coronal emission lines were observed by using optical fibre spectrometric and polarization imaging system in near infrared waveband. The profiles of the coronal emission lines including Fe XIII 10747 Å, 10798 Å and He I 10830 Å were obtained with dispersion of 0.5 Å /pix. The intensity of Fe XIII 10747 Å remained unchanged in the two different coronal regions while the intensity of He I 10830 Å varied considerably in the two coronal locations no matter whether the prominence appeared or not. The coronal polarization images were observed at Fe XI 7892 Å with a bandpass of 30 Å in a series of exposure times. [ABSTRACT FROM AUTHOR]

The flash spectra in the HeI D3 line were obtained during the 2008 total solar eclipse. This paper describes the instrument and the calibration of the obtained flash spectrum, and presents our initial results. The average integrated intensity is Eave = 8.13 × 1013 erg·cm−1·s−1·ster−1 at h = 1100 km, which confirms that the HeI D3 emission is negatively correlated with the solar activity. The surface brightness reaches a maximum of Fave = 8.25×105 erg·cm−2·s−1·ster−1 at about h ≈ (1290 ± 75) km and then decreases exponentially with height when h > 1800 km with an exponential index β = 1.63×10−8 cm−1. [ABSTRACT FROM AUTHOR]

Interior to Mercury’s orbit is a dynamically stable region where a population of small, asteroid-like bodies called Vulcanoids has been hypothesized to reside. The Vulcanoid Zone (VZ) extends inward from about 0.18 au to about 0.08 au. During the Total Solar Eclipse (TSE) in 2008, a search for Vulcanoids was completed. Although no Vulcanoids was detected to a moving object detection limit of V=12.8, the search was far more comprehensive than previous searches. [ABSTRACT FROM AUTHOR]

The last total solar eclipse on August 11, 1999, was observedon an area covered by many geomagnetic observatories and this point offers aunique opportunity to look for respective responses in the geomagnetic field. Minute values of all three field component (X, Y, Z) have been taken from four observatories in the total eclipse strip, seven observatories situated to the north from this strip and two situated to the south. Additional data from three observatories situated far from the eclipse zone were used for comparison.The overall geomagnetic activity was low during 10–12 August. Regular daily variation was clear in these days, but during the eclipse a small deviation was observed. The time position of this deviation depends on the time of the clipse. The clearest effect appeared in the Y component. The field intensity increased by about 10 nT, this increase started one hour before the middle of the eclipse and lasted one hour or a little more. The same deviation as in the totality trip appeared also on stations where only partial solar eclipse was observed with not less than 80% coverage but not on stations situated to the south. No such deviation was observed on stations situated far from the total eclipse zone. The pulsation activity was measured on four stations inside or near the total eclipse strip and on one station near the conjugate point. The pulsation amplitudes exhibit a slight minimum during the time of the eclipse. No similar minimum was observed in other times or on other days. In the original records is this minimum very weak. More clear decrease appears when a filter procedure has been applied on the record. The strongest decrease falls into the band of 15–20 s, a little less into the 20–25 s band. Similar decrease is observed also in the 8–10 s band (perhaps higher harmonics). This decrease of amplitudes was found also on records from the station located near the conjugate point where no eclipse occurred. [ABSTRACT FROM AUTHOR]