scholarly journals First quasi-Lagrangian in-situ measurements of Antarctic Polar springtime ozone: observed ozone loss rates from the Concordiasi long-duration balloon campaign

2014 ◽  
Vol 14 (16) ◽  
pp. 22245-22272
Author(s):  
R. Schofield ◽  
L. M. Avallone ◽  
L. E. Kalnajs ◽  
A. Hertzog ◽  
I. Wohltmann ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Austral Spring ◽  
Ozone Loss ◽  
Long Duration ◽  
Rate Maximum ◽  
Stratospheric Balloon ◽  
Temporal And Spatial ◽  
The Antarctic ◽  
Loss Rates

Abstract. We present ozone measurements made using state-of-the-art ultraviolet photometers onboard three long-duration stratospheric balloons launched as part of the Concordiasi campaign in austral spring 2010. Ozone loss rates calculated by matching air-parcels sampled at different times and places during the polar spring are in agreement with rates previously derived from ozonesonde measurements, for the vortex-average, ranging between 2–7 ppbv (sunlit h)−1 or 25–110 ppbv per day. However, the geographical coverage of these long-duration stratospheric balloon platforms provides new insights into the temporal and spatial patterns of ozone loss over Antarctica. Very large ozone loss rates of up to 200 ppbv day−1 (16 ppbv (sunlit h)−1) are observed for airmasses that are down-wind of the Antarctic Peninsula and/or over the East Antarctic region. The ozone loss rate maximum downstream of the Antarctic Peninsula region is consistent with high PSC occurrence from Calipso and large ClO abundances from MLS satellite observations for 12–22 September 2010.

scholarly journals First quasi-Lagrangian in situ measurements of Antarctic Polar springtime ozone: observed ozone loss rates from the Concordiasi long-duration balloon campaign

2015 ◽  
Vol 15 (5) ◽  
pp. 2463-2472 ◽  
Author(s):  
R. Schofield ◽  
L. M. Avallone ◽  
L. E. Kalnajs ◽  
A. Hertzog ◽  
I. Wohltmann ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Model Simulation ◽  
Austral Spring ◽  
Air Masses ◽  
Ozone Loss ◽  
Long Duration ◽  
Rate Maximum ◽  
Stratospheric Balloon ◽  
The Antarctic ◽  
Loss Rates

Abstract. We present ozone measurements made using state-of-the-art ultraviolet photometers onboard three long-duration stratospheric balloons launched as part of the Concordiasi campaign in austral spring 2010. Ozone loss rates calculated by matching air parcels sampled at different times and places during the polar spring are in agreement with rates previously derived from ozonesonde measurements, for the vortex average, ranging between 2 and 7 ppbv per sunlit hour or between 25 and 110 ppbv per day. However, the geographical coverage of these long-duration stratospheric balloon platforms provides new insights into the temporal and spatial patterns of ozone loss over Antarctica. Very large ozone loss rates of up to 230 ppbv per day (16 ppbv per sunlit hour) are observed for air masses that are downwind of the Antarctic Peninsula and/or over the East Antarctic region. The ozone loss rate maximum downstream of the Antarctic Peninsula region is consistent with high PSC occurrence from CALIPSO and large ClO abundances from MLS satellite observations for 12–22 September 2010, and with a chemical box model simulation using JPL 2011 kinetics with full chlorine activation.

scholarly journals An Assessment of ERA5 Reanalysis for Antarctic Near-Surface Air Temperature

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 217
Author(s):  
Jiangping Zhu ◽  
Aihong Xie ◽  
Xiang Qin ◽  
Yetang Wang ◽  
Bing Xu ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Antarctic Peninsula ◽  
Austral Summer ◽  
Correlation Coefficients ◽  
East Antarctica ◽  
West Antarctica ◽  
Austral Spring ◽  
Reanalysis Dataset ◽  
Near Surface ◽  
The Antarctic

The European Center for Medium-Range Weather Forecasts (ECMWF) released its latest reanalysis dataset named ERA5 in 2017. To assess the performance of ERA5 in Antarctica, we compare the near-surface temperature data from ERA5 and ERA-Interim with the measured data from 41 weather stations. ERA5 has a strong linear relationship with monthly observations, and the statistical significant correlation coefficients (p < 0.05) are higher than 0.95 at all stations selected. The performance of ERA5 shows regional differences, and the correlations are high in West Antarctica and low in East Antarctica. Compared with ERA5, ERA-Interim has a slightly higher linear relationship with observations in the Antarctic Peninsula. ERA5 agrees well with the temperature observations in austral spring, with significant correlation coefficients higher than 0.90 and bias lower than 0.70 °C. The temperature trend from ERA5 is consistent with that from observations, in which a cooling trend dominates East Antarctica and West Antarctica, while a warming trend exists in the Antarctic Peninsula except during austral summer. Generally, ERA5 can effectively represent the temperature changes in Antarctica and its three subregions. Although ERA5 has bias, ERA5 can play an important role as a powerful tool to explore the climate change in Antarctica with sparse in situ observations.

scholarly journals Variability in Antarctic ozone loss in the last decade (2004–2013): high-resolution simulations compared to Aura MLS observations

2015 ◽  
Vol 15 (18) ◽  
pp. 10385-10397 ◽  
Author(s):  
J. Kuttippurath ◽  
S. Godin-Beekmann ◽  
F. Lefèvre ◽  
M. L. Santee ◽  
L. Froidevaux ◽  
...  
Keyword(s):  
High Resolution ◽  
High Frequency ◽  
Polar Vortex ◽  
Ozone Loss ◽  
Maximum Loss ◽  
Vertical Range ◽  
Antarctic Ozone ◽  
June July ◽  
The Antarctic ◽  
Loss Rates

Abstract. A detailed analysis of the polar ozone loss processes during 10 recent Antarctic winters is presented with high-resolution MIMOSA–CHIM (Modèle Isentrope du transport Méso-échelle de l'Ozone Stratosphérique par Advection avec CHIMie) model simulations and high-frequency polar vortex observations from the Aura microwave limb sounder (MLS) instrument. The high-frequency measurements and simulations help to characterize the winters and assist the interpretation of interannual variability better than either data or simulations alone. Our model results for the Antarctic winters of 2004–2013 show that chemical ozone loss starts in the edge region of the vortex at equivalent latitudes (EqLs) of 65–67° S in mid-June–July. The loss progresses with time at higher EqLs and intensifies during August–September over the range 400–600 K. The loss peaks in late September–early October, when all EqLs (65–83° S) show a similar loss and the maximum loss (> 2 ppmv – parts per million by volume) is found over a broad vertical range of 475–550 K. In the lower stratosphere, most winters show similar ozone loss and production rates. In general, at 500 K, the loss rates are about 2–3 ppbv sh−1 (parts per billion by volume per sunlit hour) in July and 4–5 ppbv sh−1 in August–mid-September, while they drop rapidly to 0 by mid-October. In the middle stratosphere, the loss rates are about 3–5 ppbv sh−1 in July–August and October at 675 K. On average, the MIMOSA–CHIM simulations show that the very cold winters of 2005 and 2006 exhibit a maximum loss of ~ 3.5 ppmv around 550 K or about 149–173 DU over 350–850 K, and the warmer winters of 2004, 2010, and 2012 show a loss of ~ 2.6 ppmv around 475–500 K or 131–154 DU over 350–850 K. The winters of 2007, 2008, and 2011 were moderately cold, and thus both ozone loss and peak loss altitudes are between these two ranges (3 ppmv around 500 K or 150 ± 10 DU). The modeled ozone loss values are in reasonably good agreement with those estimated from Aura MLS measurements, but the model underestimates the observed ClO, largely due to the slower vertical descent in the model during spring.

scholarly journals Antarctic Ozone Transport and Depletion in Austral Spring 2002

2005 ◽  
Vol 62 (3) ◽  
pp. 838-847 ◽  
Author(s):  
Peter Siegmund ◽  
Henk Eskes ◽  
Peter van Velthoven
Keyword(s):  
Mass Flux ◽  
Ozone Depletion ◽  
Antarctic Region ◽  
Austral Spring ◽  
Ozone Loss ◽  
Ozone Flux ◽  
Depletion Rate ◽  
Eddy Transport ◽  
Ozone Transport ◽  
The Antarctic

Abstract The ozone budget in the Antarctic region during the stratospheric warming in 2002 is studied, using ozone analyses from the Royal Netherlands Meteorological Institute (KNMI) ozone-transport and assimilation model called TM3DAM. The results show a strong poleward ozone mass flux during this event south of 45°S between about 20 and 40 hPa, which is about 5 times as large as the ozone flux in 2001 and 2000, and is dominated by eddy transport. Above 10 hPa, there exists a partially compensating equatorward ozone flux, which is dominated by the mean meridional circulation. During this event, not only the ozone column but also the ozone depletion rate in the Antarctic region, computed as a residual from the total ozone tendency and the ozone mass flux into this region, is large. The September–October integrated ozone depletion in 2002 is similar to that in 2000 and larger than that in 2001. Simulations for September 2002 with and without ozone assimilation and parameterized ozone chemistry indicate that the parameterized ozone chemistry alone is able to produce the evolution of the ozone layer in the Antarctic region in agreement with observations. A comparison of the ozone loss directly computed from the model’s chemistry parameterization with the residual ozone loss in a simulation with parameterized chemistry but without ozone assimilation shows that the numerical error in the residual ozone loss is small.

scholarly journals In-situ aircraft observations of ice concentrations within clouds over the Antarctic Peninsula and Larsen Ice Shelf

2012 ◽  
Vol 12 (7) ◽  
pp. 17295-17345
Author(s):  
D. P. Grosvenor ◽  
T. W. Choularton ◽  
T. Lachlan-Cope ◽  
M. W. Gallagher ◽  
J. Crosier ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Particle Production ◽  
Supercooled Liquid ◽  
Ice Crystals ◽  
Ice Crystal ◽  
Ice Shelf ◽  
Aircraft Observations ◽  
The Antarctic ◽  
Larsen Ice Shelf

Abstract. In-situ aircraft observations of ice crystal concentrations in Antarctic clouds are presented for the first time. Orographic, layer and wave clouds around the Antarctic Peninsula and Larsen Ice shelf regions were penetrated by the British Antarctic Survey's Twin Otter Aircraft, which was equipped with modern cloud physics probes. The clouds studied were mostly in the free troposphere and hence ice crystals blown from the surface are unlikely to have been a major source for the ice phase. The temperature range covered by the experiments was 0 to −21°C. The clouds were found to contain supercooled liquid water in most regions and at heterogeneous ice formation temperatures ice crystal concentrations (60 s averages) were often less than 0.07 l−1, although values up to 0.22 l−1 were observed. Estimates of observed aerosol concentrations were used as input into the DeMott et al., 2010 ice nuclei (IN) parameterisation. The observed ice crystal number concentrations were generally in broad agreement with the IN predictions, although on the whole the predicted values were higher. Possible reasons for this are discussed and include the lack of IN observations in this region with which to characterise the parameterisation, and/or problems in relating ice concentration measurements to IN concentrations. Other IN parameterisations significantly overestimated the number of ice particles. Generally ice particle concentrations were much lower than found in clouds in middle latitudes for a given temperature. Higher ice crystal concentrations were sometimes observed at temperatures warmer than −9 °C, with values of several per litre reached. These were attributable to secondary ice particle production by the Hallett Mossop process. Even in this temperature range it was observed that there were regions with little or no ice that were dominated by supercooled liquid water. It is likely that in some cases this was due to a lack of seeding ice crystals to act as rimers to initiate secondary ice particle production. This highlights the complicated nature of this process and indicates that the accurate representation of it in global models is likely to represent a challenge. However, the contrast between Hallett Mossop zone ice concentrations and the fairly low concentrations of heterogeneously nucleated ice suggests that the Hallet Mossop process has the potential to be very important in remote, pristine regions such as around the Antarctic coast.

scholarly journals Variability of Antarctic ozone loss in the last decade (2004–2013): high resolution simulations compared to Aura MLS observations

2014 ◽  
Vol 14 (20) ◽  
pp. 28203-28230 ◽  
Author(s):  
J. Kuttippurath ◽  
S. Godin-Beekmann ◽  
F. Lefèvre ◽  
M. L. Santee ◽  
L. Froidevaux ◽  
...  
Keyword(s):  
High Resolution ◽  
Polar Vortex ◽  
Ozone Loss ◽  
Maximum Loss ◽  
Vertical Range ◽  
Antarctic Ozone ◽  
June July ◽  
The Antarctic ◽  
Polar Ozone ◽  
Loss Rates

Abstract. A detailed analysis of the polar ozone loss processes during ten recent Antarctic winters is presented with high resolution Mimosa-Chim model simulations and high frequency polar vortex observations from the Aura Microwave Limb Sounder (MLS) instrument. Our model results for the Antarctic winters 2004–2013 show that chemical ozone loss starts in the edge region of the vortex at equivalent latitudes (EqLs) of 65–69° S in mid-June/July. The loss progresses with time at higher EqLs and intensifies during August–September over the range 400–600 K. The loss peaks in late September/early October, where all EqLs (65–83°) show similar loss and the maximum loss (>2 ppmv [parts per million by volume]) is found over a broad vertical range of 475–550 K. In the lower stratosphere, most winters show similar ozone loss and production rates. In general, at 500 K, the loss rates are about 2–3 ppbv sh−1 (parts per billion by volume/sunlit hour) in July and 4–5 ppbv sh−1 in August/mid-September, while they drop rapidly to zero by late September. In the middle stratosphere, the loss rates are about 3–5 ppbv sh−1 in July–August and October at 675 K. It is found that the Antarctic ozone hole (June–September) is controlled by the halogen cycles at about 90–95% (ClO–ClO, BrO–ClO, and ClO–O) and the loss above 700 K is dominated by the NOx cycle at about 70–75%. On average, the Mimosa-Chim simulations show that the very cold winters of 2005 and 2006 exhibit a maximum loss of ~3.5 ppmv around 550 K or about 149–173 DU over 350–850 K and the warmer winters of 2004, 2010, and 2012 show a loss of ~2.6 ppmv around 475–500 K or 131–154 DU over 350–850 K. The winters of 2007, 2008, and 2011 were moderately cold and thus both ozone loss and peak loss altitudes are between these two ranges (3 ppmv around 500 K or 150 ± 10 DU). The modeled ozone loss values are in reasonably good agreement with those estimated from Aura MLS measurements, but the model underestimates the observed ClO, largely due to the slower vertical descent in the model during spring.

scholarly journals In-situ aircraft observations of ice concentrations within clouds over the Antarctic Peninsula and Larsen Ice Shelf

2012 ◽  
Vol 12 (23) ◽  
pp. 11275-11294 ◽  
Author(s):  
D. P. Grosvenor ◽  
T. W. Choularton ◽  
T. Lachlan-Cope ◽  
M. W. Gallagher ◽  
J. Crosier ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Particle Production ◽  
Supercooled Liquid ◽  
Ice Crystals ◽  
Ice Crystal ◽  
Ice Shelf ◽  
Aircraft Observations ◽  
The Antarctic ◽  
Larsen Ice Shelf

Abstract. In-situ aircraft observations of ice crystal concentrations in Antarctic clouds are presented for the first time. Orographic, layer and wave clouds around the Antarctic Peninsula and Larsen Ice shelf regions were penetrated by the British Antarctic Survey's Twin Otter aircraft, which was equipped with modern cloud physics probes. The clouds studied were mostly in the free troposphere and hence ice crystals blown from the surface are unlikely to have been a major source for the ice phase. The temperature range covered by the experiments was 0 to −21 °C. The clouds were found to contain supercooled liquid water in most regions and at heterogeneous ice formation temperatures ice crystal concentrations (60 s averages) were often less than 0.07 l−1, although values up to 0.22 l−1 were observed. Estimates of observed aerosol concentrations were used as input into the DeMott et al. (2010) ice nuclei (IN) parameterisation. The observed ice crystal number concentrations were generally in broad agreement with the IN predictions, although on the whole the predicted values were higher. Possible reasons for this are discussed and include the lack of IN observations in this region with which to characterise the parameterisation, and/or problems in relating ice concentration measurements to IN concentrations. Other IN parameterisations significantly overestimated the number of ice particles. Generally ice particle concentrations were much lower than found in clouds in middle latitudes for a given temperature. Higher ice crystal concentrations were sometimes observed at temperatures warmer than −9 °C, with values of several per litre reached. These were attributable to secondary ice particle production by the Hallett Mossop process. Even in this temperature range it was observed that there were regions with little or no ice that were dominated by supercooled liquid water. It is likely that in some cases this was due to a lack of seeding ice crystals to act as rimers to initiate secondary ice particle production. This highlights the chaotic and spatially inhomogeneous nature of this process and indicates that the accurate representation of it in global models is likely to represent a challenge. However, the contrast between Hallett Mossop zone ice concentrations and the fairly low concentrations of heterogeneously nucleated ice suggests that the Hallet Mossop process has the potential to be very important in remote, pristine regions such as around the Antarctic coast.

Demosponges from the sublittoral and shallow-circalittoral (<24m depth) Antarctic Peninsula with a description of four new species and notes on in situ identification characteristics

Zootaxa ◽  
2019 ◽  
Vol 4658 (3) ◽  
pp. 461-508
Author(s):  
CLAIRE E. GOODWIN ◽  
JADE BERMAN ◽  
KATHARINE R. HENDRY
Keyword(s):  
New Species ◽  
Antarctic Peninsula ◽  
Scuba Diving ◽  
Sponge Species ◽  
Widespread Species ◽  
The Antarctic

Specimens were collected by SCUBA diving from 22 sites along the Antarctic Peninsula, spanning latitudes from Diomedea Island (62°12.185’S) to Jenny Island (67°43.325’S). The aims of the survey were to record the sponge biodiversity of the sublittoral and shallow-circalittoral and to provide information on in situ identification features. In total 24 sponge species were recorded, ranging from 0 to 12 species per site. The most widespread species were Dendrilla antarctica (10 sites), Sphaerotylus antarcticus (11 sites); and Mycale (Oxymycale) acerata (13 sites). Four species new to science were discovered and are described here: Megaciella cardenasi sp. nov., Crella (Crella) hennequinae sp. nov., Hymedesmia (Hymedesmia) noramaloneae sp. nov., Clathria (Clathria) priestleyae sp. nov. Suberites topsenti (Burton, 1929) is reassigned to Hemimycale topsenti (Burton, 1929) comb. nov. General habitat notes are provided for the survey sites, many of which were previously unsurveyed.

scholarly journals The impact of transport across the polar vortex edge on Match ozone loss estimates

2008 ◽  
Vol 8 (3) ◽  
pp. 565-578 ◽  
Author(s):  
J.-U. Grooß ◽  
R. Müller ◽  
P. Konopka ◽  
H.-M. Steinhorst ◽  
A. Engel ◽  
...  
Keyword(s):  
Time Integration ◽  
Polar Vortex ◽  
Lagrangian Model ◽  
Match Method ◽  
Ozone Loss ◽  
Air Sampler ◽  
The Impact ◽  
Loss Rates

Abstract. The Match method for the quantification of polar chemical ozone loss is investigated mainly with respect to the impact of the transport of air masses across the vortex edge. For the winter 2002/03, we show that significant transport across the vortex edge occurred and was simulated by the Chemical Lagrangian Model of the Stratosphere. In-situ observations of inert tracers and ozone from HAGAR on the Geophysica aircraft and balloon-borne sondes, and remote observations from MIPAS on the ENVISAT satellite were reproduced well by CLaMS. The model even reproduced a small vortex remnant that remained a distinct feature until June 2003 and was also observed in-situ by a balloon-borne whole air sampler. We use this CLaMS simulation to quantify the impact of transport across the vortex edge on ozone loss estimates from the Match method. We show that a time integration of the determined vortex average ozone loss rates, as performed in Match, results in a larger ozone loss than the polar vortex average ozone loss in CLaMS. The determination of the Match ozone loss rates is also influenced by the transport of air across the vortex edge. We use the model to investigate how the sampling of the ozone sondes on which Match is based represents the vortex average ozone loss rate. Both the time integration of ozone loss and the determination of ozone loss rates for Match are evaluated using the winter 2002/2003 CLaMS simulation. These impacts can explain the majority of the differences between CLaMS and Match column ozone loss. While the investigated effects somewhat reduce the apparent discrepancy in January ozone loss rates reported earlier, a distinct discrepancy between simulations and Match remains. However, its contribution to the accumulated ozone loss over the winter is not large.

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