scholarly journals IASI carbon monoxide validation over the Arctic during POLARCAT spring and summer campaigns

2010 ◽  
Vol 10 (6) ◽  
pp. 14445-14494 ◽  
Author(s):  
M. Pommier ◽  
K. S. Law ◽  
C. Clerbaux ◽  
S. Turquety ◽  
D. Hurtmans ◽  
...  

Abstract. In this paper, we provide a detailed comparison between carbon monoxide (CO) data measured by the Infrared Atmospheric Sounding Interferometer (IASI)/METOP and aircraft measurements over the Arctic. The CO measurements were obtained during North American campaigns (NASA ARCTAS and NOAA ARCPAC) and European campaigns (POLARCAT-France, POLARCAT-GRACE and YAK-AEROSIB) as part of the International Polar Year (IPY) in spring and summer 2008. During the campaigns different air masses were sampled including clean air, polluted plumes originating from anthropogenic sources in Europe, Asia and North America, and forest fire plumes originating from Siberia and Canada. CO-rich plumes following different transport pathways were captured well by the IASI instrument, illustrated for example by a transport event over the North Pole from Asia on 9 July 2008. The comparison between the IASI CO profiles and aircraft data was achieved by first completing the latter for higher altitudes using a latitudinally dependent climatology of ACE-FTS satellite CO profiles (2004–2009) and by subsequently smoothing the resulting full profiles by the IASI averaging kernels. Proceeding this way, the IASI profiles were shown to be in good agreement with smoothed in situ profiles (with a difference of about 10 ppbv) in spring. In summer, the IASI profiles were higher than the smoothed in situ profiles below 8 km, for all polluted cases. Correlations between IASI and combination ACE-FTS/aircraft derived total columns varied from 0.15 to 0.74 in spring and 0.26 to 0.84 in summer, with better results over the sea in spring (0.73) and over the land in summer (0.69).

2010 ◽  
Vol 10 (21) ◽  
pp. 10655-10678 ◽  
Author(s):  
M. Pommier ◽  
K. S. Law ◽  
C. Clerbaux ◽  
S. Turquety ◽  
D. Hurtmans ◽  
...  

Abstract. In this paper, we provide a detailed comparison between carbon monoxide (CO) data measured by the Infrared Atmospheric Sounding Interferometer (IASI)/MetOp and aircraft observations over the Arctic. The CO measurements were obtained during North American (NASA ARCTAS and NOAA ARCPAC) and European campaigns (POLARCAT-France, POLARCAT-GRACE and YAK-AEROSIB) as part of the International Polar Year (IPY) POLARCAT activity in spring and summer 2008. During the campaigns different air masses were sampled including clean air, polluted plumes originating from anthropogenic sources in Europe, Asia and North America, and forest fire plumes originating from Siberia and Canada. The paper illustrates that CO-rich plumes following different transport pathways were well captured by the IASI instrument, in particular due to the high spatial coverage of IASI. The comparison between IASI CO total columns, 0–5 km partial columns and profiles with collocated aircraft data was achieved by taking into account the different sensitivity and geometry of the sounding instruments. A detailed analysis is provided and the agreement is discussed in terms of information content and surface properties at the location of the observations. For profiles, the data were found to be in good agreement in spring with differences lower than 17%, whereas in summer the difference can reach 20% for IASI profiles below 8 km for polluted cases. For total columns the correlation coefficients ranged from 0.15 to 0.74 (from 0.47 to 0.77 for partial columns) in spring and from 0.26 to 0.84 (from 0.66 to 0.88 for partial columns) in summer. A better agreement is seen over the sea in spring (0.73 for total column and 0.78 for partial column) and over the land in summer (0.69 for total columns and 0.81 for partial columns). The IASI vertical sensitivity was better over land than over sea, and better over land than over sea ice and snow allowing a higher potential to detect CO vertical distribution during summer.


2012 ◽  
Vol 12 (16) ◽  
pp. 7371-7389 ◽  
Author(s):  
M. Pommier ◽  
C. Clerbaux ◽  
K. S. Law ◽  
G. Ancellet ◽  
P. Bernath ◽  
...  

Abstract. Ozone data retrieved in the Arctic region from infrared radiance spectra recorded by the Infrared Atmospheric Sounding Interferometer (IASI) on board the MetOp-A European satellite are presented. They are compared with in situ and lidar observations obtained during a series of aircraft measurement campaigns as part of the International Polar Year POLARCAT activities in spring and summer 2008. Different air masses were sampled during the campaigns including clean air, polluted plumes originating from anthropogenic sources, forest fire plumes from the three northern continents, and stratospheric-influenced air masses. The comparison between IASI O3 [0–8 km], [0–12 km] partial columns and profiles with collocated aircraft observations is achieved by taking into account the different sensitivity and geometry of the sounding instruments. A detailed analysis is provided and the agreement is discussed in terms of vertical sensitivity and surface properties at the location of the observations. Overall, IASI O3 profiles are found to be in relatively good agreement with smoothed in situ and lidar profiles in the free troposphere with differences of less than 40% (25% over sea for both seasons) and 10%, respectively. The correlation between IASI O3 retrieved partial columns and the smoothed aircraft partial columns is good with DC-8 in situ data in spring over North America (r = 0.68), and over Greenland with ATR-42 lidar measurements in summer (r = 0.67). Correlations with other data are less significant highlighting the difficulty of IASI to capture precisely the O3 variability in the Arctic upper troposphere and lower stratosphere (UTLS). This is particularly noted in comparison with the [0–12 km] partial columns. The IASI [0–8 km] partial columns display a low negative bias (by less than 26% over snow) compared to columns derived from in situ measurements. Despite the relatively high biases of the IASI retrievals in the Arctic UTLS, our analysis shows that IASI can be used to identify, using O3 / CO ratios, stratospheric intrusions.


2011 ◽  
Vol 11 (12) ◽  
pp. 33127-33171
Author(s):  
M. Pommier ◽  
C. Clerbaux ◽  
K. S. Law ◽  
G. Ancellet ◽  
P. Bernath ◽  
...  

Abstract. Ozone data retrieved in the Arctic region from infrared radiance spectra recorded by the Infrared Atmospheric Sounding Interferometer (IASI) on board the MetOp-A European satellite are presented. They are compared with in situ and lidar observations obtained during a series of aircraft measurement campaigns as part of the International Polar Year (IPY) POLARCAT activities in spring and summer 2008. Different air masses were sampled during the campaigns including clean air, polluted plumes originating from anthropogenic sources, forest fire plumes from the three northern continents, and stratospheric-influenced air masses. The comparison between IASI O3 [0–8 km], [0–12 km] partial columns and profiles with collocated aircraft observations is achieved by taking into account the different sensitivity and geometry of the sounding instruments. A detailed analysis is provided and the agreement is discussed in terms of information content and surface properties at the location of the observations. Overall, IASI O3 profiles are found to be in relatively good agreement in the free troposphere with smoothed in situ and lidar profiles with differences less than 40% (25% over the sea for both seasons) and 10%, respectively. The correlation between IASI O3 retrieved partial columns and the smoothed aircraft partial columns is good with DC-8 in situ data in spring over North American forest fire regions (r = 0.68), and over Greenland with ATR-42 lidar measurements in summer (r = 0.67). Correlations with other data are less significant highlighting the difficulty with which IASI is able to capture O3 variability in the Arctic upper troposphere and lower stratosphere (UTLS) with sufficient precision as noted in comparison with the [0–12 km] partial columns. However the [0–8 km] partial columns show good results with IASI which displays a negative bias (maximum of 26% over snow) compared to columns derived from in situ measurements. Despite these difficulties in the Arctic UTLS, this work also shows that IASI can be used to study particular cases where stratospheric intrusions are present using a O3/CO ratio diagnostic.


2016 ◽  
Vol 97 (6) ◽  
pp. 1033-1056 ◽  
Author(s):  
Taneil Uttal ◽  
Sandra Starkweather ◽  
James R. Drummond ◽  
Timo Vihma ◽  
Alexander P. Makshtas ◽  
...  

Abstract International Arctic Systems for Observing the Atmosphere (IASOA) activities and partnerships were initiated as a part of the 2007–09 International Polar Year (IPY) and are expected to continue for many decades as a legacy program. The IASOA focus is on coordinating intensive measurements of the Arctic atmosphere collected in the United States, Canada, Russia, Norway, Finland, and Greenland to create synthesis science that leads to an understanding of why and not just how the Arctic atmosphere is evolving. The IASOA premise is that there are limitations with Arctic modeling and satellite observations that can only be addressed with boots-on-the-ground, in situ observations and that the potential of combining individual station and network measurements into an integrated observing system is tremendous. The IASOA vision is that by further integrating with other network observing programs focusing on hydrology, glaciology, oceanography, terrestrial, and biological systems it will be possible to understand the mechanisms of the entire Arctic system, perhaps well enough for humans to mitigate undesirable variations and adapt to inevitable change.


Author(s):  
Jan Zalasiewicz ◽  
Mark Williams

Ellesmere Island today is a destination only to a particular type of tourist: rich enough to afford the most exclusive of package tours, and hardy (or ascetic) enough to yearn for the spiritual purity of an icy wasteland, rather than the sensual pleasures of a Mediterranean seashore. The island is large—twice the size of Iceland. Yet, its largest settlement, Grise Fjord (or, in the local Inuktitut language, Aijuittuk—‘the place that never thaws’) has but some 140 souls—while its smallest, Eureka, bizarrely but somehow appropriately, was listed in 2006 as having precisely none. Squeezed between northern Canada and Greenland, Ellesmere Island is well within the Arctic Circle, and its northern tip is not much more than 700 kilometres from the North Pole. A land of mountains, fjords, glaciers, and ice-fields, it has been dubbed ‘the horizontal Everest’. In the short summer, the Sun never leaves the sky, and temperatures might, on brief sunny days, exceed 20 °C. When the winter months come, the Sun never rises, and temperatures drop below –40 °C. The only tree that can grow, here and there, is the dwarf Arctic willow, usually knee-high, while the mammals—musk ox, caribou, seals—have attracted Inuit hunters for some 4,000 years (and more lately, Viking explorers too). It was the handsomely whiskered First Lieutenant Adolphus Washington Greely (1844–1935) of the United States Army who discovered the ancient forest that had lain there, deeply buried, for fifty million years, a forest as expressive of bygone glories as any Arthurian legend. As part of the First International Polar Year, in 1882, he had been given charge of a party of soldiers, and tasked with making magnetic and meteorological measurements in the far north. They explored the Greenland coast, and traversed Ellesmere Island from east to west, stumbling upon the forest in the course of these journeys. The voyage killed most of his men, and almost killed him. When the relief crews arrived, two years late (the expedition had not been ideally planned) only six men, including Greely, were left alive. They had survived—just—by eating their own boots and, it seems, the remains of their dead colleagues.


Ocean Science ◽  
2017 ◽  
Vol 13 (3) ◽  
pp. 379-410 ◽  
Author(s):  
Burkard Baschek ◽  
Friedhelm Schroeder ◽  
Holger Brix ◽  
Rolf Riethmüller ◽  
Thomas H. Badewien ◽  
...  

Abstract. The Coastal Observing System for Northern and Arctic Seas (COSYNA) was established in order to better understand the complex interdisciplinary processes of northern seas and the Arctic coasts in a changing environment. Particular focus is given to the German Bight in the North Sea as a prime example of a heavily used coastal area, and Svalbard as an example of an Arctic coast that is under strong pressure due to global change.The COSYNA automated observing and modelling system is designed to monitor real-time conditions and provide short-term forecasts, data, and data products to help assess the impact of anthropogenically induced change. Observations are carried out by combining satellite and radar remote sensing with various in situ platforms. Novel sensors, instruments, and algorithms are developed to further improve the understanding of the interdisciplinary interactions between physics, biogeochemistry, and the ecology of coastal seas. New modelling and data assimilation techniques are used to integrate observations and models in a quasi-operational system providing descriptions and forecasts of key hydrographic variables. Data and data products are publicly available free of charge and in real time. They are used by multiple interest groups in science, agencies, politics, industry, and the public.


2019 ◽  
Vol 19 (6) ◽  
pp. 3927-3937 ◽  
Author(s):  
Daniel Mewes ◽  
Christoph Jacobi

Abstract. Arctic amplification causes the meridional temperature gradient between middle and high latitudes to decrease. Through this decrease the large-scale circulation in the midlatitudes may change and therefore the meridional transport of heat and moisture increases. This in turn may increase Arctic warming even further. To investigate patterns of Arctic temperature, horizontal transports and their changes in time, we analysed ERA-Interim daily winter data of vertically integrated horizontal moist static energy transport using self-organizing maps (SOMs). Three general transport pathways have been identified: the North Atlantic pathway with transport mainly over the northern Atlantic, the North Pacific pathway with transport from the Pacific region, and the Siberian pathway with transport towards the Arctic over the eastern Siberian region. Transports that originate from the North Pacific are connected to negative temperature anomalies over the central Arctic. These North Pacific pathways have been becoming less frequent during the last decades. Patterns with origin of transport in Siberia are found to have no trend and show cold temperature anomalies north of Svalbard. It was found that transport patterns that favour transport through the North Atlantic into the central Arctic are connected to positive temperature anomalies over large regions of the Arctic. These temperature anomalies resemble the warm Arctic–cold continents pattern. Further, it could be shown that transport through the North Atlantic has been becoming more frequent during the last decades.


Polar Record ◽  
2008 ◽  
Vol 44 (2) ◽  
pp. 107-114 ◽  
Author(s):  
Øystein Jensen

ABSTRACTWith the International Polar Year (IPY) having commenced in March 2007, key issues relating to the polar regions are again in focus. This article reviews one central legal issue re-emerging in the Arctic: global regulation of safety standards for international shipping. The ‘Guidelines for ships operating in Arctic ice-covered waters’ are examined, with a view to the probable expansion of shipping in the Arctic in near future. Following an introduction to navigational issues within the Arctic context, the article describes how the guidelines came into being, and then analyses key elements and structure of the regulations and shortfalls of today's arrangements. The possible relevance of the guidelines to the Antarctic is also discussed briefly. Finally, the article inquires into the key repercussions of introducing binding regulations.


2008 ◽  
Vol 25 (11) ◽  
pp. 2091-2105 ◽  
Author(s):  
R. Krishfield ◽  
J. Toole ◽  
A. Proshutinsky ◽  
M-L. Timmermans

Abstract An automated, easily deployed Ice-Tethered Profiler (ITP) instrument system, developed for deployment on perennial sea ice in the polar oceans to measure changes in upper ocean water properties in all seasons, is described, and representative data from prototype instruments are presented. The ITP instrument consists of three components: a surface subsystem that sits atop an ice floe; a weighted, plastic-jacketed wire-rope tether of arbitrary length (up to 800 m) suspended from the surface element; and an instrumented underwater unit that employs a traction drive to profile up and down the wire tether. ITPs profile the water column at a programmed sampling interval; after each profile, the underwater unit transfers two files holding oceanographic and engineering data to the surface unit using an inductive modem and from the surface instrument to a shore-based data server using an Iridium transmitter. The surface instrument also accumulates battery voltage readings, buoy temperature data, and locations from a GPS receiver at a specified interval (usually every hour) and transmits those data daily. Oceanographic and engineering data are processed, displayed, and made available in near–real time (available online at http://www.whoi.edu/itp). Six ITPs were deployed in the Arctic Ocean between 2004 and 2006 in the Beaufort gyre with various programmed sampling schedules of two to six one-way traverses per day between 10- and 750–760-m depth, providing more than 5300 profiles in all seasons (as of July 2007). The acquired CTD profile data document interesting spatial variations in the major water masses of the Canada Basin, show the double-diffusive thermohaline staircase that lies above the warm, salty Atlantic layer, measure seasonal surface mixed layer deepening, and document several mesoscale eddies. Augmenting the systems already deployed and to replace expiring systems, an international array of more than one dozen ITPs will be deployed as part of the Arctic Observing Network during the International Polar Year (IPY) period (2007–08) holding promise for more valuable real-time upper ocean observations for operational needs, to support studies of ocean processes, and to facilitate numerical model initialization and validation.


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