Evidence of large scale ozone depletion within the Arctic Polar Vortex 94/95 based on airborne LIDAR measurements

The Arctic winter of 2019-2020 was characterized by an unusually persistent polar vortex and temperatures in the lower stratosphere that were consistently below the threshold for the formation of polar stratospheric clouds (PSCs). These conditions led to ozone loss that is comparable to the Antarctic ozone hole. Ground-based measurements from a suite of instruments at the Polar Environment Atmospheric Research Laboratory (PEARL) in Eureka, Canada (80.05&#176;N, 86.42&#176;W) were used to investigate chemical ozone depletion. The vortex was located above Eureka longer than in any previous year in the 20-year dataset and lidar measurements provided evidence of polar stratospheric clouds (PSCs) above Eureka. Additionally, UV-visible zenith-sky Differential Optical Absorption Spectroscopy (DOAS) measurements showed record ozone loss in the 20-year dataset, evidence of denitrification along with the slowest increase of NO2 during spring, as well as enhanced reactive halogen species (OClO and BrO). Complementary measurements of HCl and ClONO2 (chlorine reservoir species) from a Fourier transform infrared (FTIR) spectrometer showed unusually low columns that were comparable to 2011, the previous year with significant chemical ozone depletion. Record low values of HNO3 in the FTIR dataset are in accordance with the evidence of PSCs and a denitrified atmosphere. Estimates of chemical ozone loss were derived using passive ozone from the SLIMCAT offline chemical transport model to account for dynamical contributions to the stratospheric ozone budget.

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Global Hawk dropsonde observations of the Arctic atmosphere obtained during the Winter Storms and Pacific Atmospheric Rivers (WISPAR) field campaign

Atmospheric Measurement Techniques ◽

10.5194/amt-7-3917-2014 ◽

2014 ◽

Vol 7 (11) ◽

pp. 3917-3926 ◽

Cited By ~ 9

Author(s):

J. M. Intrieri ◽

G. de Boer ◽

M. D. Shupe ◽

J. R. Spackman ◽

J. Wang ◽

...

Keyword(s):

Large Scale ◽

Polar Vortex ◽

Unmanned Aircraft ◽

The Arctic ◽

Winter Storms ◽

Field Campaign ◽

Atmospheric Rivers ◽

The North ◽

Aircraft System ◽

Global Hawk

Abstract. In February and March of 2011, the Global Hawk unmanned aircraft system (UAS) was deployed over the Pacific Ocean and the Arctic during the Winter Storms and Pacific Atmospheric Rivers (WISPAR) field campaign. The WISPAR science missions were designed to (1) mprove our understanding of Pacific weather systems and the polar atmosphere; (2) evaluate operational use of unmanned aircraft for investigating these atmospheric events; and (3) demonstrate operational and research applications of a UAS dropsonde system at high latitudes. Dropsondes deployed from the Global Hawk successfully obtained high-resolution profiles of temperature, pressure, humidity, and wind information between the stratosphere and surface. The 35 m wingspan Global Hawk, which can soar for ~ 31 h at altitudes up to ~ 20 km, was remotely operated from NASA's Dryden Flight Research Center at Edwards Air Force Base (AFB) in California. During the 25 h polar flight on 9–10 March 2011, the Global Hawk released 35 sondes between the North Slope of Alaska and 85° N latitude, marking the first UAS Arctic dropsonde mission of its kind. The polar flight transected an unusually cold polar vortex, notable for an associated record-level Arctic ozone loss, and documented polar boundary layer variations over a sizable ocean–ice lead feature. Comparison of dropsonde observations with atmospheric reanalyses reveal that, for this day, large-scale structures such as the polar vortex and air masses are captured by the reanalyses, while smaller-scale features, including low-level jets and inversion depths, are mischaracterized. The successful Arctic dropsonde deployment demonstrates the capability of the Global Hawk to conduct operations in harsh, remote regions. The limited comparison with other measurements and reanalyses highlights the potential value of Arctic atmospheric dropsonde observations where routine in situ measurements are practically nonexistent.

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Causes of the Record-Breaking Pacific Northwest Heatwave, Late June 2021

Atmosphere ◽

10.3390/atmos12111434 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1434

Author(s):

James E. Overland

Keyword(s):

Pacific Northwest ◽

Large Scale ◽

Polar Vortex ◽

The Arctic ◽

Large Temperature ◽

Extreme Heat Event ◽

The Pacific ◽

Heat Event ◽

Large Scale Atmospheric Circulation ◽

The Bering Sea

The extreme heat event that hit the Pacific Northwest (Oregon, Washington, southern British Columbia) at the end of June 2021 was 3 °C greater than the previous Seattle record of 39 °C; larger extremes of 49 °C were observed further inland that were 6 °C above previous record. There were hundreds of deaths over the region and loss of marine life and forests. At the large scale prior to the event, the polar vortex was split over the Arctic. A polar vortex instability center formed over the Bering Sea and then extended southward along the west coast of North America. The associated tropospheric trough (low geopotential heights) established a multi-day synoptic scale Omega Block (west-east oriented low/high/low geopotential heights) centered over the Pacific Northwest. Warming was sustained in the region due to subsidence/adiabatic heating and solar radiation, which were the main reasons for such large temperature extremes. The seasonal transition at the end of spring suggests the possibility of a southern excursion of a polar vortex/jet stream pair. Both the Pacific Northwest event in 2021 and the Siberian heatwave climax in June 2020 may be examples of crossing a critical state in large-scale atmospheric circulation variability.

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Monitoring tropical forest carbon stocks and emissions using Planet satellite data

Scientific Reports ◽

10.1038/s41598-019-54386-6 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 18

Author(s):

Ovidiu Csillik ◽

Pramukta Kumar ◽

Joseph Mascaro ◽

Tara O’Shea ◽

Gregory P. Asner

Keyword(s):

Climate Change ◽

Large Scale ◽

Cost Effective ◽

Carbon Stocks ◽

Airborne Lidar ◽

Aboveground Carbon ◽

Lidar Measurements ◽

High Resolution Map ◽

Aboveground Carbon Density ◽

Planet Satellite

AbstractTropical forests are crucial for mitigating climate change, but many forests continue to be driven from carbon sinks to sources through human activities. To support more sustainable forest uses, we need to measure and monitor carbon stocks and emissions at high spatial and temporal resolution. We developed the first large-scale very high-resolution map of aboveground carbon stocks and emissions for the country of Peru by combining 6.7 million hectares of airborne LiDAR measurements of top-of-canopy height with thousands of Planet Dove satellite images into a random forest machine learning regression workflow, obtaining an R2 of 0.70 and RMSE of 25.38 Mg C ha−1 for the nationwide estimation of aboveground carbon density (ACD). The diverse ecosystems of Peru harbor 6.928 Pg C, of which only 2.9 Pg C are found in protected areas or their buffers. We found significant carbon emissions between 2012 and 2017 in areas aggressively affected by oil palm and cacao plantations, agricultural and urban expansions or illegal gold mining. Creating such a cost-effective and spatially explicit indicators of aboveground carbon stocks and emissions for tropical countries will serve as a transformative tool to quantify the climate change mitigation services that forests provide.

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Airborne lidar measurements of ozone, water vapor, and aerosols in large-scale atmospheric studies

Proceedings of IGARSS '93 - IEEE International Geoscience and Remote Sensing Symposium ◽

10.1109/igarss.1993.322200 ◽

2002 ◽

Author(s):

E.V. Browell

Keyword(s):

Water Vapor ◽

Large Scale ◽

Airborne Lidar ◽

Lidar Measurements

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The use of SMILES data to study ozone loss in the Arctic winter 2009/2010 and comparison with Odin/SMR data using assimilation techniques

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-12855-2014 ◽

2014 ◽

Vol 14 (23) ◽

pp. 12855-12869 ◽

Cited By ~ 5

Author(s):

K. Sagi ◽

D. Murtagh ◽

J. Urban ◽

H. Sagawa ◽

Y. Kasai

Keyword(s):

Ozone Depletion ◽

Transport Model ◽

Space Station ◽

Polar Vortex ◽

The Arctic ◽

Mixing Ratio ◽

Weather Forecasts ◽

Ozone Loss ◽

Medium Range ◽

Assimilation Model

Abstract. The Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on board the International Space Station observed ozone in the stratosphere with high precision from October 2009 to April 2010. Although SMILES measurements only cover latitudes from 38° S to 65° N, the combination of data assimilation methods and an isentropic advection model allows us to quantify the ozone depletion in the 2009/2010 Arctic polar winter by making use of the instability of the polar vortex in the northern hemisphere. Ozone data from both SMILES and Odin/SMR (Sub-Millimetre Radiometer) for the winter were assimilated into the Dynamical Isentropic Assimilation Model for OdiN Data (DIAMOND). DIAMOND is an off-line wind-driven transport model on isentropic surfaces. Wind data from the operational analyses of the European Centre for Medium- Range Weather Forecasts (ECMWF) were used to drive the model. In this study, particular attention is paid to the cross isentropic transport of the tracer in order to accurately assess the ozone loss. The assimilated SMILES ozone fields agree well with the limitation of noise induced variability within the SMR fields despite the limited latitude coverage of the SMILES observations. Ozone depletion has been derived by comparing the ozone field acquired by sequential assimilation with a passively transported ozone field initialized on 1 December 2009. Significant ozone loss was found in different periods and altitudes from using both SMILES and SMR data: The initial depletion occurred at the end of January below 550 K with an accumulated loss of 0.6–1.0 ppmv (approximately 20%) by 1 April. The ensuing loss started from the end of February between 575 K and 650 K. Our estimation shows that 0.8–1.3 ppmv (20–25 %) of O3 has been removed at the 600 K isentropic level by 1 April in volume mixing ratio (VMR).

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The impact of mid-latitude intrusions into the polar vortex on ozone loss estimates

Atmospheric Chemistry and Physics ◽

10.5194/acp-3-395-2003 ◽

2003 ◽

Vol 3 (2) ◽

pp. 395-402 ◽

Cited By ~ 9

Author(s):

J.-U. Grooß ◽

R. Müller

Keyword(s):

Large Scale ◽

Loss Rate ◽

Polar Vortex ◽

Control Measures ◽

Lagrangian Model ◽

The Arctic ◽

Match Method ◽

Ozone Loss ◽

The Impact ◽

Loss Rates

Abstract. Current stratospheric chemical model simulations underestimate substantially the large ozone loss rates that are derived for the Arctic from ozone sondes for January of some years. Until now, no explanation for this discrepancy has been found. Here, we examine the influence of intrusions of mid-latitude air into the polar vortex on these ozone loss estimates. This study focuses on the winter 1991/92, because during this winter the discrepancy between simulated and experimentally derived ozone loss rates is reported to be the largest. Also during the considered period the vortex was disturbed by a strong warming event with large-scale intrusions of mid-latitude air into the polar vortex, which is quite unusual for this time of the year. The study is based on simulations performed with the Chemical Lagrangian Model of the Stratosphere (CLaMS). Two methods for determination the ozone loss are investigated, the so-called vortex average approach and the Match method. The simulations for January 1992 show that the intrusions induce a reduction of vortex average ozone mixing ratio corresponding to a systematic offset of the ozone loss rate of about 12 ppb per day. This should be corrected for in the vortex average method. The simulations further suggest, that these intrusions do not cause a significant bias for the Match method due to effective quality control measures in the Match technique.

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Vertical structure of Antarctic tropospheric ozone depletion events: characteristics and broader implications

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-10-8189-2010 ◽

2010 ◽

Vol 10 (3) ◽

pp. 8189-8246 ◽

Cited By ~ 2

Author(s):

A. E. Jones ◽

P. S. Anderson ◽

E. W. Wolff ◽

H. K. Roscoe ◽

G. J. Marshall ◽

...

Keyword(s):

High Altitude ◽

Ozone Depletion ◽

Tropospheric Ozone ◽

Large Scale ◽

Field Experiments ◽

Strong Association ◽

Vertical Component ◽

Low Pressure ◽

The Arctic ◽

Low Pressure Systems

Abstract. The majority of tropospheric ozone depletion event (ODE) studies have focussed on time-series measurements, with comparatively few studies of the vertical component. Those that exist have almost exclusively used free-flying balloon-borne ozonesondes and almost all have been conducted in the Arctic. Here we use measurements from two separate Antarctic field experiments to examine the vertical profile of ozone during Antarctic ODEs. We use tethersonde data to probe details in the lowest few hundred meters and find considerable structure in the profiles associated with complex atmospheric layering. The profiles were all measured at wind speeds less than 7 ms−1, and on each occasion the lowest inversion height lay between 10 m and 40 m. We also use data from a free-flying ozonesonde study to select events where ozone depletion was recorded at altitudes >1 km above ground level. Using ERA-40 meteorological charts, we find that on every occasion the high altitude depletion was preceded by an atmospheric low pressure system. An examination of limited published ozonesonde data from other Antarctic stations shows this to be a consistent feature. Given the link between BrO and ODEs, we also examine ground-based and satellite BrO measurements, and find a strong association between enhanced BrO and atmospheric low pressure systems. The results suggest that, in Antarctica, such depressions are responsible for driving high altitude ODEs and for generating the large-scale BrO clouds observed from satellites. In the Arctic, the prevailing meteorology differs from that in Antarctica, but we show that major low pressure systems in the Arctic, when they occur, can also generate BrO clouds. Such depressions thus appear to be fundamental when considering the broader influence of ODEs, particularly in Antarctica, such as halogen export and the radiative influence of ozone-depleted air masses.

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Robust effects of springtime Arctic ozone depletion on surface climate

10.21203/rs.3.rs-496081/v1 ◽

2021 ◽

Author(s):

Marina Friedel ◽

Gabriel Chiodo ◽

Andrea Stenke ◽

Daniela Domeisen ◽

Stephan Fueglistaler ◽

...

Keyword(s):

Ozone Depletion ◽

Climate Model ◽

Stratospheric Ozone ◽

Polar Vortex ◽

Negative Temperature ◽

Significant Degree ◽

The Arctic ◽

Surface Climate ◽

Northern Hemispheric ◽

The Impact

Abstract Massive spring ozone loss due to anthropogenic emissions of ozone depleting substances is not limited to the austral hemisphere, but can also occur in the Arctic. Previous studies have suggested a link between springtime Arctic ozone depletion and Northern Hemispheric surface climate, which might add surface predictability. However, so far it has not been possible to isolate the role of stratospheric ozone from dynamical downward impacts. For the first time, we quantify the impact of springtime Arctic ozone depletion on surface climate using observations and targeted chemistry-climate model experiments to isolate the effects of ozone feedbacks. We find that springtime stratospheric ozone depletion is followed by surface anomalies in precipitation and temperature resembling a positive Arctic Oscillation. Most notably, we show that these anomalies, affecting large portions of the Northern Hemisphere, cannot be explained by dynamical variability alone, but are to a significant degree driven by stratospheric ozone. The surface signal is linked to reduced shortwave absorption by stratospheric ozone, forcing persistent negative temperature anomalies in the lower stratosphere and a delayed breakup of the polar vortex - analogous to ozone-surface coupling in the Southern Hemisphere.These results suggest that Arctic stratospheric ozone actively forces springtime Northern Hemispheric surface climate and thus provides a source of predictability on seasonal scales.

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Four Fourier transform spectrometers and the Arctic polar vortex: instrument intercomparison and ACE-FTS validation at Eureka during the IPY springs of 2007 and 2008

Atmospheric Measurement Techniques ◽

10.5194/amt-3-51-2010 ◽

2010 ◽

Vol 3 (1) ◽

pp. 51-66 ◽

Cited By ~ 15

Author(s):

R. L. Batchelor ◽

F. Kolonjari ◽

R. Lindenmaier ◽

R. L. Mittermeier ◽

W. Daffer ◽

...

Keyword(s):

Fourier Transform ◽

Atmospheric Chemistry ◽

Ozone Depletion ◽

Polar Vortex ◽

The Arctic ◽

Satellite Mission ◽

International Polar Year ◽

Important Species ◽

Gas Measurements ◽

Chemistry Experiment

Abstract. The Canadian Arctic Atmospheric Chemistry Experiment Validation Campaigns have been carried out at Eureka, Nunavut (80.05° N, 86.42° W) during the polar sunrise period since 2004. During the International Polar Year (IPY) springs of 2007 and 2008, three ground-based Fourier transform infrared (FTIR) spectrometers were operated simultaneously. This paper presents a comparison of trace gas measurements of stratospherically important species involved in ozone depletion, namely O3, HCl, ClONO2, HNO3 and HF, recorded with these three spectrometers. Total column densities of the gases measured with the new Canadian Network for the Detection of Atmospheric Change (CANDAC) Bruker 125HR are shown to agree to within 3.5% with the existing Environment Canada Bomem DA8 measurements. After smoothing both of these sets of measurements to account for the lower spectral resolution of the University of Waterloo Portable Atmospheric Research Interferometric Spectrometer for the Infrared (PARIS-IR), the measurements were likewise shown to agree with PARIS-IR to within 7%. Concurrent measurements of these gases were also made with the satellite-based Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) during overpasses of Eureka during these time periods. While one of the mandates of the ACE satellite mission is to study ozone depletion in the polar spring, previous validation exercises have identified the highly variable polar vortex conditions of the spring period to be a challenge for validation efforts. In this work, comparisons between the CANDAC Bruker 125HR and ACE-FTS have been used to develop strict criteria that allow the ground- and satellite-based instruments to be confidently compared. When these criteria are taken into consideration, the observed biases between the ACE-FTS and ground-based FTIR spectrometer are not persistent for both years and are generally insignificant, though small positive biases of ~5%, comparable in magnitude to those seen in previous validation exercises, are observed for HCl and HF in 2007, and negative biases of −15.3%, −4.8% and −1.5% are seen for ClONO2, HNO3 and O3 in 2008.

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