Mauna Loa Volcano Research Articles

From the dark side of paradise: a new natural replication of cave planthopper evolution from Hawaiian lava tubes (Hemiptera: Fulgoromorpha: Cixiidae)

Abstract The Hawaiian Islands are known to harbour a rich and diverse fauna of troglobionts (obligate subterranean species). To date, 74 obligate cavernicolous arthropod species have been documented from across the main Hawaiian islands, the majority of which were from Hawaiʻi Island, and mostly from lava tubes of Kilauea volcano, the youngest volcano on the island. A recent bioinventory of the Kipuka Kanohina lava tube system on the south-western side of Mauna Loa volcano revealed the existence of previously unknown cave-adapted species. Among them is the first cave-adapted species of the planthopper genus Iolania, Iolania frankanstonei Hoch & Porter sp. nov. Morphological and molecular data suggest that the species is closely related to the epigean (i.e. surface-dwelling) species Iolania perkinsi, which occurs in surface environments on Hawaiʻi Island. Thus, parapatric speciation is assumed, further corroborating the assumption that adaptive shifts are the major evolutionary patterns underlying the evolution of troglobionts on young oceanic islands.

Topography‐Incorporated Adjoint‐State Surface Wave Traveltime Tomography: Method and a Case Study in Hawaii

AbstractIn this study we recast surface wave traveltime tomography as an inverse problem constrained by an eikonal equation and solve it using the efficient adjoint‐state method. Specifically, recognizing that large topographic variations and high surface wave frequencies can make the topographic effect too significant to ignore, we employ an elliptically anisotropic eikonal equation to describe the traveltime fields of surface waves on undulated topography. The sensitivity kernel of the traveltime objective function with respect to shear wave velocity is derived using the adjoint‐state method. As a result, the newly developed method is inherently applicable to any study regions, whether with or without significant topographic variations. Hawaii is one of the most seismically and magmatically active regions. However, its significant topographic variations have made it less accurate to investigate using conventional surface wave traveltime tomography methods. To tackle this problem, we applied our new method to invert ambient noise Rayleigh wave phase traveltimes and construct a 3D shear wave velocity model. Our results reveal features that are consistent with geological structures and previous tomography results, including high velocities below Mauna Loa Volcano and Kilauea Volcano, and low velocities beneath the Hilina Fault Zone. Additionally, our model reveals a high‐velocity anomaly to the South of Hualalai's summit, which may be related to a buried rift zone. Our findings further demonstrate that including topography can lead to a correction of up to 0.8% in the shear wave velocity model of Hawaii, an island spanning approximately 100 km with volcanoes reaching elevations exceeding 4 km.

VogCast: A Framework for Modeling Volcanic Air Pollution and Its Application to the 2022 Eruption of Mauna Loa Volcano, Hawai'i

AbstractVolcanic activity and the associated gas emissions into the atmosphere often result in adverse air quality conditions and present a hazard to human health and the environment. Building on a decade‐long effort to provide operational surface sulfur dioxide and sulfate aerosol forecasts for the State of Hawai'i, we present an air quality modeling framework called VogCast. VogCast is designed to simplify ensemble air quality prediction on a regional scale by linking together multiple state‐of‐the‐art models of meteorology, emissions, and dispersion. The framework is open‐source and introduces a new dynamic plume‐rise algorithm for distributing pollutants vertically. Using radar and satellite data, we demonstrate that VogCast reasonably captured the mean injection height, the location, and the general envelope of the vog plume during Mauna Loa's 2022 eruption. The results suggest that during the 12‐day eruption period model performance varied between days with trade and non‐trade wind conditions. Our findings also highlight the importance of sulfur dioxide emission rate and vent parameter inputs for improving forecast accuracy. The broad goal of this work is to better our understanding of vog dispersion and improve air quality prediction for impacted communities.

Characterizing and Locating Seismic Tremor during the 2022 Eruption of Mauna Loa Volcano, Hawai’i, with Network Covariance

Abstract The 2022 eruption of Mauna Loa Volcano, Hawai’i, was accompanied by continuous seismic tremor that began about 30 min before and ended several days after the eruption. We characterize the amplitude history and frequency content of the tremor, and we use a network covariance-based method to estimate its source location. The tremor exhibits multiple narrow spectral peaks between 1 and 3 Hz, and its amplitude varies through time in a spasmodic manner. Our location results track a northeast migration of shallow sources through the summit region in the first few hours of the eruption. For the remainder of the eruption, source locations cluster in the vicinity of the erupting vent in the northeast rift zone. We attribute the tremor source to gas dynamics in the upper reaches of a basaltic dike. However, limitations in instrumentation and knowledge of the subsurface velocity structure may preclude an assessment of the source mechanism. Our results illustrate the value of characterizing and locating tremor for tracking magma movement, and demonstrate a use for dense and calibrated seismic instrumentation on active volcanoes. The location method we use requires substantial parameter testing, reflecting the potential benefit of developing more flexible approaches toward real-time automated assessment of tremor at volcanoes.

Mauna Loa awakens

On 27 November 2022, Hawaii’s Mauna Loa volcano on the Big Island began erupting for the first time in 38 years. A day later, a flight over the eruption captured this photo. It clearly shows a line of fissures, at an elevation of 3 km, from which lava flowed across the volcano’s northeast rift zone. The eruption continued for about two weeks, with lava traveling some 20 km from the summit. The US Geological Survey observed an increase in the number of earthquakes beneath the volcano’s cauldron-shaped summit and to the northwest roughly two months before the eruption began. The island’s nearby Kīlauea volcano has been erupting since September 2021.PPT|High resolutionThe two volcanoes appear to be connected underground by a deep, widespread network of pathways, according to a recently published paper by researchers from Caltech. Although previous studies have hypothesized that such a network may exist, the large data set the Caltech team analyzed showed enough seismic activity to map out a detailed plumbing system that connects Mauna Loa to Kīlauea, 34 km away. Future monitoring of volcanic activity may benefit from considering both volcanoes as part of a larger, interconnected system. (J. D. Wilding et al., Science 379, 462, 2023, doi:10.1126/science.ade5755; image courtesy of the US Geological Survey.) Section:ChooseTop of page <<© 2023 American Institute of Physics.

Elastic interaction between Mauna Loa and Kīlauea evidenced by independent component analysis

The contrasting dynamics between Mauna Loa and Kīlauea have been studied over the last 100 years from multiple viewpoints. The fact that dynamic changes of one volcano trigger a dynamic response of the other volcano indicates a connection may exist. Petrological works show a direct relationship between the magmatic systems of these two volcanoes is not possible. We analysed DInSAR data and GPS measurements of ground deformation patterns associated with the activity of Mauna Loa and Kīlauea volcanoes. The DInSAR SBAS dataset spans the interval between 2003 and 2010, and was acquired along ascending and descending orbits of the ENVISAT (ESA) satellite under different look angles. Of the 10 tracks that cover the Big Island (Hawai‘i), 4 cover both volcanic edifices. Using GPS measurements, we computed the areal strain on 15 triplets of stations for Kīlauea volcano and 11 for Mauna Loa volcano. DInSAR data was analysed by applying Independent Component Analysis (ICA) to decompose the time-varying ground deformation pattern of both volcanoes. The results revealed anticorrelated ground deformation behaviour of the main calderas of Mauna Loa and Kīlauea, meaning that the opposite response is seen in the ground deformation of one volcano with respect to the other. At the same time, Kīlauea exhibits a more complex pattern, with an additional component, which appears not to be correlated with the dynamics of Mauna Loa. The GPS areal strain time series support these findings. To corroborate and help interpret the results, we performed inverse modelling of the observed ground deformation pattern using analytical source models. The results indicate that the ground deformation of Mauna Loa is associated with a dike-shaped source located at 6.2 km depth. In comparison, the anticorrelated ground deformation of Kīlauea is associated with a volumetric source at 1.2 km depth. This excludes a hydraulic connection as a possible mechanism to explain the anticorrelated behaviour; instead, we postulate a stress-transfer mechanism. To support this hypothesis, we performed a 3D numerical modelling of stress and strain fields in the study area, determining the elastic interaction of each source over the others. The most relevant finding is that the Mauna Loa shallow plumbing system can affect the shallowest magmatic reservoir of Kīlauea, while the opposite scenario is unlikely. Conversely, the second independent component observed at Kīlauea is associated to a sill-shaped source located at a depth of 3.5 km, which is less affected by this interaction process.

ОПРЕДЕЛЕНИЕ ОБЩЕГО СОДЕРЖАНИЯ ДИОКСИДА УГЛЕРОДА НАД ТЕРРИТОРИЕЙ РОССИИ ПО ДАННЫМ ОТЕЧЕСТВЕННОГО КОСМИЧЕСКОГО АППАРАТА “МЕТЕОР-М” № 2

A description is given of the method for the retrieval of atmospheric column-averaged dry-air mole fractions of carbon dioxide (XCO2) from the data of IKFS-2 infrared Fourier spectrometer on board the Meteor-M Russian meteorological satellites. The method is based on estimating XCO2 using a second-order regression, whose predictors are the effective spectral optical depths of the atmosphere in the infrared region of 8-14 μm. The optical depth is determined using spectral intensities of outgoing radiation measured by the IKFS-2 as well as the calculated intensities of the Earth’s surface or cloud top simulated as a gray body with temperature T s. The temperature T s is retrieved from IKFS-2 measurements within the atmospheric microwindow at the wave number equal to 900.1 cm-1. The reference XCO2 values for constructing the regression were the results of contact CO2 measurements on the tall tower at the ZOTTO international observatory (Central Siberia) and at the NOAA observatory on the Mauna Loa volcano (Hawaii) in 2015-2016. The methodology was validated by comparing the XCO2 retrieved from Meteor-M No. 2 IKFS-2 measurements with parallel measurements over Siberia by the OCO and CrIS satellite spectrometers on board the OCO-2 and NOAA-20 satellites (USA). The maximum discrepancies in the daily estimates of the spatially averaged XCO2 during October 9-19, 2021 derived from the IKFS-2 data do not exceed 2.3 ppm versus the OCO data and 5 ppm versus the CrIS data.

Two new species of Mecyclothorax Sharp, 1903 (Coleoptera: Carabidae: Moriomorphini) from the Island of Hawai‵i

Two species of the Mecyclothorax argutor (Sharp, 1903) species-group, M. neonomas sp. nov. and M. brunneonubiger sp. nov., are newly described from Mauna Loa volcano on the Island of Hawai‵i. Mecyclothorax neonomas is most similar morphologically to M. swezeyi Liebherr, 2008 of Mauna Kea and is therefore proposed as its adelphotaxon. Conversely, the adelphotaxon proposed for M. brunneonubiger is M. blackburnianus Liebherr, 2008, precinctive to Kohala volcano, Island of Hawai‵i. Based on the younger geological age of origin of Mauna Loa relative to Mauna Kea and Kohala, it is hypothesized these two newly described, sympatric species arose via progressive colonization of Mauna Loa during development of the geologically dynamic Island of Hawai‵i. A revised key to all Mecyclothorax species known from Hawai‵i Island is provided.

Geological tasks during HI-SEAS planetary analog mission simulations, Mauna Loa, Hawai'i

The Hawai'i Space Exploration Analog and Simulation (HI-SEAS) project is a NASA-funded research program operating long-duration planetary analog surface mission simulations on Mauna Loa volcano, Hawai'i. During missions lasting from 4 to 12 months, crews of six analog astronaut participants live and work in an isolated habitat, communicating with a remote mission support team via a 20-min time delay. The main purpose of HI-SEAS is to study team effectiveness and adaptation over time in isolated, confined, and high autonomy mission scenarios. Among other duties, Crewmembers are tasked with routinely conducting geological fieldwork requiring extravehicular activity (EVA) in the environment surrounding the habitat. They must determine how they will accomplish these tasks, conduct the tasks themselves, and report results by a due date set by the remote science team. Here we describe the design, task parameters, and performance outcomes of HI-SEAS geology EVA tasks from four 6-person missions. We describe the assigned tasks, how the crews carried out their assignments, and the results of their work in terms of six performance metrics for each task: 1) number of days required for completion; 2) number of crewmembers participating; 3) number of EVAs required; 4) total EVA time required; 5) difference between required and planned EVA times; and 6) performance score evaluating how well crew met the task objective. We find weak evidence of a decrease in geology task performance during the third quarter of missions M2-M4. This dataset provides insights into varying crew performance over time for different mission durations.

WESTERN EXPLORERS AND VOLCANIC HEAT IN HAWAIʻI

This paper is the first to compile the accounts of Western explorers to Hawai‘i who used volcanic heat. During the 1800s, Western explorers used volcanic heat when climbing and surveying Kīlauea and Mauna Loa volcanoes in Hawai‘i. The explorers cooked food on steam vents and lava streams. They drank condensed water from volcanic steam and bathed in a warm basin and warm springs. They warmed themselves near steam cracks and a lava stream, lit cigarettes with Kīlauea’s lava lake, and collected rocks. To confirm the presence of volcanic heat, this study uses geothermal resource maps and data from the Hawai‘i Play Fairway project. The areas where the explorers used volcanic heat have a probability of volcanic heat of 0.7 to 1.0, and elevated temperatures in nearby water wells indicate heat sources. Kīlauea and Mauna Loa erupted numerous times, and the surrounding areas experienced volcanic steam releases and lava flows. The explorers used volcanic heat to facilitate not only their survival but also the Western exploration and scientific investigation of Kīlauea and Mauna Loa volcanoes.

Southward growth of Mauna Loa\u2019s dike-like magma body driven by topographic stress

Space-geodetic observations of a new period of inflation at Mauna Loa volcano, Hawaii, recorded an influx of 0.11 km3 of new magma into it’s dike-like magma body during 2014–2020. The intrusion started after at least 4 years of decollement slip under the eastern flank creating > 0.15 MPa opening stresses in the rift zone favorable for magma intrusion. Volcanoes commonly respond to magma pressure increase with the injection of a dike, but Mauna Loa responded with lateral growth of its magma body in the direction of decreasing topographic stress. In 2017, deformation migrated back, and inflation continued at the pre-2015 location. Geodetic inversions reveal a 8 × 8.5, 10 × 3 and 9 × 4 km2 dike-like magma body during the 2014–2015, 2015–2018 and 2018–2020 periods, respectively, and an average decollement slip of ~ 23 cm/year along a 10 × 5 km2 fault. The evolution of the dike-like magma body including the reduction in vertical extent is consistent with a slowly ascending dike propagating laterally when encountering a stress barrier and freezing its tip when magma influx waned. Overall, the magma body widened about 4.5 m during 2002–2020.

Spatio-temporal variation of atmospheric CH4 concentration and its driving factors in monsoon Asia.

Based on the ground-based observations from seven atmospheric background stations during 2009 to 2018 in monsoon Asia (including BKT station in Indonesia, LLN and WLG stations in China, RYO and YON stations in Japan, TAP station in Republic of Korea, and UUM station in Mongolia), we analyzed the temporal and spatial variation of atmospheric CH4 concentration and its driving factors using harmonic model and maximal information-based nonparametric exploration. The results showed that the CH4 concentration in monsoon Asia varied from 1853.04 to 1935.61 nmol·mol-1, higher than that in Mauna Loa (MLO) station (1838.33 nmol·mol-1) in Hawaii, USA. The CH4 concentration decreased from north to south, with the highest value in TAP station (1935.61 nmol·mol-1) in Republic of Korea and RYO station (1907.19 nmol·mol-1) in Japan. The average seasonal amplitude at YON station in Japan was the largest (108.20 nmol·mol-1); while that at WLG station in China was the smallest (29.48 nmol·mol-1). The seasonal amplitude of TAP station in Republic of Korea changed faster at the rate of 4.49 nmol·mol-1·a-1. Except for WLG and TAP stations, CH4 concentrations were low in summer and high in winter. From the long-term perspective, the CH4 concentration at LLN (7.68 nmol·mol-1·a-1) and WLG (7.56 nmol·mol-1·a-1) stations in China exhibited the most obvious growth trend. Compared with wind speed, temperature and precipitation had greater impact on CH4 concentration, which were negatively associated with CH4 concentration. Local CH4 emission at some stations had a significant positive effect on CH4 concentration.

TOURISTS PLAY WITH LAVA AND VOLCANIC HEAT: KĪLAUEA VOLCANO’S EARLY CONTRIBUTIONS TO HAWAI‘I’S TOURISM INDUSTRY

ABSTRACT Kīlauea Volcano has attracted visitors to Hawai‘i throughout the history of Hawai‘i’s tourism industry. From the 1870s to the 1910s, Kīlauea offered the experience of using volcanic heat and molten lava to cook food, melt postcards onto cavern walls, enflame items, and obtain souvenirs including scorched postcards, rocks, olivine, and Pele’s hair. Writers shared their experiences in publications, and traveling presentations showed American audiences images of visitors scorching postcards at Kīlauea. Marketing campaigns on the U.S. Mainland promoted Hawai‘i as a tourist destination and promoted cooking with Kīlauea’s heat. In 1907, U.S. Congressmen toured Kīlauea Caldera, ate dinner cooked with Kīlauea’s heat, and learned about Kīlauea’s geodiversity. These experiences likely influenced Congress to establish the Kīlauea, Haleakalā, and Mauna Loa Volcanoes as the Hawaii National Park (now known as the Hawai‘i Volcanoes National Park). Today, the U.S. National Park Service maintains the Hawai‘i Volcanoes National Park, and it offers geological, biological, and cultural resources for recreation and education. For destination marketing, Kīlauea provided Hawai‘i a comparative advantage for tourism.

Causes of slowing-down seasonal CO2 amplitude at Mauna Loa.

Changing amplitude of the seasonal cycle of atmospheric CO2 (SCA) in the northern hemisphere is an emerging carbon cycle property. Mauna Loa (MLO) station (20°N, 156°W), which has the longest continuous northern hemisphere CO2 record, shows an increasing SCA before the 1980s (p<.01), followed by no significant change thereafter. We analyzed the potential driving factors of SCA slowing-down, with an ensemble of dynamic global vegetation models (DGVMs) coupled with an atmospheric transport model. We found that slowing-down of SCA at MLO is primarily explained by response of net biome productivity (NBP) to climate change, and by changes in atmospheric circulations. Through NBP, climate change increases SCA at MLO before the 1980s and decreases it afterwards. The effect of climate change on the slowing-down of SCA at MLO is mainly exerted by intensified drought stress acting to offset the acceleration driven by CO2 fertilization. This challenges the view that CO2 fertilization is the dominant cause of emergent SCA trends at northern sites south of 40°N. The contribution of agricultural intensification on the deceleration of SCA at MLO was elusive according to land-atmosphere CO2 flux estimated by DGVMs and atmospheric inversions. Our results also show the necessity to adequately account for changing circulation patterns in understanding carbon cycle dynamics observed from atmospheric observations and in using these observations to benchmark DGVMs.

Long-term temporal variations and source changes of halocarbons in the Greater Pearl River Delta region, China

Abstract Halocarbons are widely used in the Greater Pearl River Delta (PRD) region of China. To study the long-term trends, source changes and emissions of major halocarbons, a total of 1505 canister air samples were collected in the Greater PRD region during 2001–2018. Mixing ratios of CFCs decreased significantly over the past 18 years except for CFC-114, which significantly increased in the Greater PRD, consistent with the recent observations of significant CFC-114 emissions in East Asia. Declines in CFCs in the Greater PRD region were faster than those at the background Mauna Loa (MLO) site, indicating effective control regulations. Source apportionment simulations showed that refrigeration applications, including refrigeration industry and CFCs replacement, were the main sources of halocarbons. During the study period, refrigeration industry experienced a progressive decline in both mixing ratio and percentage, while the contribution of CFCs replacement remained increasing. Contribution of solvent use in electronic industry traced by C2Cl4 dramatically decreased during the study period, and stayed at a low level in recent years. Based on the measured ratios of halocarbons to CO, the estimated total halocarbon emissions in 2016 were 46.5 ± 16.7 Gg for the Greater PRD region. This study provides useful information for examining the evolving emission status of halocarbons in the Greater PRD region in response to control strategies and changing usage.

Response of Male Hawaii Elepaio Chasiempis sandwichensis to Conspecific Songs: A Small-Scale Playback Study

Las aves paseriformes aprenden sus cantos principalmente a traves de la transmision cultural. Sin embargo, la fragmentacion del habitat puede provocar una variacion cultural en el aprendizaje de cantos dando lugar a restricciones en la transmision de informacion cultural, incluyendo interacciones acusticas. En este estudio, nuestro objetivo es evaluar la respuesta individual a vocalizaciones de la misma especie dentro de dos poblaciones diferentes, asi como entre ambas poblaciones. Para ello, utilizamos reproducciones de cantos del monarca elepaio Chasiempis sandwichensis en un paisaje fragmentado que se encuentra en la ladera noreste del volcan Mauna loa (Isla de Hawai, EE.UU.). Evaluamos la respuesta de los machos de monarca elepaio a los cantos grabados en su misma poblacion, asi como en una poblacion diferente. Tambien comparamos vocalizaciones entre ambas poblaciones para evaluar diferenciacion acustica. Nuestros resultados indican divergencias comportamentales en la respuesta al canto de esta especie a pequena escala, asi como diferencias significativas en rasgos acusticos. Sin embargo, contrariamente a lo que se esperaba, los individuos de monarca elepaio de ambas poblaciones no variaron en su patron de respuesta a los cantos en funcion de su origen. Esto sugiere que la diferenciacion acustica puede no ser lo suficientemente fuerte como para dar lugar a una divergencia comportamental en la respuesta de los individuos de monarca elepaio, a pesar de la existencia de diferencias entre los rasgos acusticos de ambas poblaciones.

Pūhāhonu: Earth's biggest and hottest shield volcano

New bathymetric and gravity mapping, refined volume calculations and petrologic analyses show that the Hawaiian volcano Pūhāhonu is the largest and hottest shield volcano on Earth. This ∼12.5-14.1 Ma volcano in the northwest Hawaiian Ridge (NWHR) is twice the size of Mauna Loa volcano (148 ± 29 vs. 74.0×103km3), which was assumed to be not only the largest Hawaiian volcano but also the largest known shield volcano. We considered four testable mechanisms to increase magma production, including 1) thinner lithosphere, 2) slower propagation rate, 3) more fertile source, and 4) hotter mantle. The first three of these have been ruled out. The lithosphere was old (∼88 Myrs) when Pūhāhonu was formed, and thus, too thick and cold to allow for greater extents of partial melting. The propagation rate was relatively fast when it erupted (87 km/Myr), so this is another unlikely reason. Source fertility was Kea-like and no more fertile than for other much smaller NWHR volcanoes. A hotter mantle remains the best mechanism to produce the large magma volumes and is consistent with the high forsteritic olivine phenocryst compositions (up to 91.8%) and the calculated high percent of melting (24%). Thus, the gargantuan size of Pūhāhonu reflects its high melting temperature, the highest reported for any Cenozoic basalt. A solitary wave within the Hawaiian plume is the probable cause of Pūhāhonu's higher melting temperature and the resulting increased volume flux given the absence of a more fertile source for Pūhāhonu basalts, as found for many basalts from the Hawaiian Islands.

Vapor transport of silver and gold in basaltic lava flows

Abstract We documented occurrences of native copper (Cu), silver (Ag), and gold (Au) in a pāhoehoe flow from Kīlauea volcano (Hawaii, USA), an a‘ā flow from Mauna Loa volcano (Hawaii), and a mid-oceanic-ridge basalt (MORB) from the Chile Ridge (southeastern Pacific Ocean). Native Ag in Kīlauea and MORB samples consistently contained minor Cl (&lt;1 wt%). Native Ag in Hawaiian basalts can occur at the center of nearly circular patches of relatively evolved minerals, which presumably formed after late-stage silicate liquid infilled pipe vesicles. Sulfur loss and oxidation of a Cu-sulfide phase can explain the native Cu, but not Au and Ag deposition. The rare occurrence of native Cu-Au-Ag alloys and the large native Au and Ag grain size suggest separate metal precipitation mechanisms. A fractional crystallization and degassing model envisions initial Au and Ag enrichment in crystallizing interstitial liquid and further enrichment in a separating vapor phase. From the flow interior, the metals ascend through ephemeral pipe vesicles as bisulfide (Au) or chloride (Ag) vapor complexes and precipitate in the transition zone below the upper vesicular zone, owing to temperature and oxidation state changes. Our results support igneous vapor transport of ore elements in mafic plutonic systems and imply preconcentration of gold during lava solidification before later hydrothermal remobilization.

Tropospheric water vapor profiles obtained with FTIR: comparison with balloon-borne frost point hygrometers and influence on trace gas retrievals

Abstract. Retrievals of vertical profiles of key atmospheric gases provide a critical long-term record from ground-based Fourier transform infrared (FTIR) solar absorption measurements. However, the characterization of the retrieved vertical profile structure can be difficult to validate, especially for gases with large vertical gradients and spatial–temporal variability such as water vapor. In this work, we evaluate the accuracy of the most common water vapor isotope (H216O, hereafter WV) FTIR retrievals in the lower and upper troposphere–lower stratosphere. Coincident high-quality vertically resolved WV profile measurements obtained from 2010 to 2016 with balloon-borne NOAA frost point hygrometers (FPHs) are used as reference to evaluate the performance of the retrieved profiles at two sites: Boulder (BLD), Colorado, and at the mountaintop observatory of Mauna Loa (MLO), Hawaii. For a meaningful comparison, the spatial–temporal variability has been investigated. We present results of comparisons among FTIR retrievals with unsmoothed and smoothed FPH profiles to assess WV vertical gradients. Additionally, we evaluate the quantitative impact of different a priori profiles in the retrieval of WV. An orthogonal linear regression analysis shows the best correlation among tropospheric layers using ERA-Interim (ERA-I) a priori profiles and biases are lower for unsmoothed comparisons. In Boulder, we found a negative bias of 0.02±1.9 % (r=0.95) for the 1.5–3 km layer. A larger negative bias of 11.1±3.5 % (r=0.97) was found in the lower free troposphere layer of 3–5 km attributed to rapid vertical change of WV, which is not always captured by the retrievals. The bias improves in the 5–7.5 km layer (1.0±5.3 %, r=0.94). The bias remains at about 13 % for layers above 7.5 km but below 13.5 km. At MLO the spatial mismatch is significantly larger due to the launch of the sonde being farther from the FTIR location. Nevertheless, we estimate a negative bias of 5.9±4.6 % (r=0.93) for the 3.5–5.5 km layer and 9.9±3.7 % (r=0.93) for the 5.5–7.5 km layer, and we measure positive biases of 6.2±3.6 % (r=0.95) for the 7.5–10 km layer and 12.6 % and greater values above 10 km. The agreement for the first layer is significantly better at BLD because the air masses are similar for both FTIR and FPH. Furthermore, for the first time we study the influence of different WV a priori profiles in the retrieval of selected gas profiles. Using NDACC standard retrievals we present results for hydrogen cyanide (HCN), carbon monoxide (CO), and ethane (C2H6) by taking NOAA FPH profiles as the ground truth and evaluating the impact of other WV profiles. We show that the effect is minor for C2H6 (bias &lt;0.5 % for all WV sources) among all vertical layers. However, for HCN we found significant biases between 6 % for layers close to the surface and 2 % for the upper troposphere depending on the WV profile source. The best results (reduced bias and precision and r values closer to unity) are always found for pre-retrieved WV. Therefore, we recommend first retrieving WV to use in subsequent retrieval of gases.

Study on Carbon Dioxide, Methane, Sulfur Dioxide, Temperature, Ozone and Rainfall Variations in Hawaiian Island (190 34’ Latitude, 1550 30’ Longitude)

The Hawaii observatory is located at 190 34’ latitude, 1550 30’ longitude and 4207 sq m area. The island of Hawaii is built from fine separate shield volcanoes that erupted somewhat sequentially one overlapping the other. Moderate to strong trade winds carry as and vog from Kilauea volcano around the southern tip of the island. Ninety-nine percent of the gas molecules emitted during a volcanic eruptions are water vapor (H2O), carbon dioxide (Co2), and sulfur dioxide (So2). The remaining one percent is comprised of small amounts of hydrogen sulfide, carbon monoxide, hydrogen chloride, hydrogen fluoride, and other minor gas species. The most critical factors that determine how much vog impacts any area are wind direction and speed. Where and how bad the vog is ultimately depends on several additional factors including air temperature, humidity, and rainfall emitted from Kīlauea Volcano. The Co2 atmosphere concentration measured at Mauna Lao observatory (MLO). Hawaii have been used by advocates of anthropological global warming (AGW) as a bell weather of climate. Carbon dioxide concentrations in units of parts per million (PPM) have been measured daily and monthly have been averages reported since 1958. We have analyzed Co2 data from 1958 to 2014, So2 data from 1979 to 1997, CH4 data from 1992 to 2001, rainfall data from 1920 to 2012, temperature data from 1955 to 2015 and ozone data from 1958 to 2014. Here We have analyzed and interpret to draw the line graphs and bar graphs in the following parameters ozone, carbon dioxide, methane, temperature and rainfall. We find the following parameters i) Co2 gradually increased from 1958 to 2014 ii) CH4 gradually increased from 1992 to 2001 iii) The So2 gradually increased and decreased from 1979 to 1997 iv) Mauna loa Temperature increased from 1955 to 2015 and Opihihale Temperature increased from 1965 to 2010 v) Rainfall increased and decreased from 1920 to 2012 vi) Ozone increased and decreased from 1958 to 2014.