Conformal subgroup extreme surface

AbstractAtmospheric rivers (ARs) are long and narrow regions of strong horizontal water vapor transport. Upon landfall, ARs are typically associated with heavy precipitation and strong surface winds. A quantitative understanding of the atmospheric conditions that favor extreme surface winds during ARs has implications for anticipating and managing various impacts associated with these potentially hazardous events. Here, a global AR database (1999–2014) with relevant information from MERRA-2 reanalysis, QuikSCAT and AIRS satellite observations are used to better understand and quantify the role of near-surface static stability in modulating surface winds during landfalling ARs. The temperature difference between the surface and 1 km MSL (ΔT; used here as a proxy for near-surface static stability), and integrated water vapor transport (IVT) are analyzed to quantify their relationships to surface winds using bivariate linear regression. In four regions where AR landfalls are common, the MERRA-2-based results indicate that IVT accounts for 22-38% of the variance in surface wind speed. Combining ΔT with IVT increases the explained variance to 36-52%. Substitution of QuikSCAT surface winds and AIRS ΔT in place of the MERRA-2 data largely preserves this relationship (e.g., 44% compared to 52% explained variance for USA West Coast). Use of an alternate static stability measure–the bulk Richardson number–yields a similar explained variance (47%). Lastly, AR cases within the top and bottom 25% of near-surface static stability indicate that extreme surface winds (gale or higher) are more likely to occur in unstable conditions (5.3%/14.7% during weak/strong IVT) than in stable conditions (0.58%/6.15%).

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Observed and predicted sensitivities of extreme surface ozone to meteorological drivers in three US cities

Atmospheric Environment ◽

10.1016/j.atmosenv.2017.12.036 ◽

2018 ◽

Vol 176 ◽

pp. 292-300 ◽

Cited By ~ 5

Author(s):

Miranda J. Fix ◽

Daniel Cooley ◽

Alma Hodzic ◽

Eric Gilleland ◽

Brook T. Russell ◽

...

Keyword(s):

Surface Ozone ◽

Extreme Surface ◽

Us Cities

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The Okhotsk tropospheric cyclone and its role in the occurrence of extreme air temperature in January in 1950-2019

Hydrometeorological research and forecasting ◽

10.37162/2618-9631-2021-3-64-79 ◽

2021 ◽

Vol 3 ◽

pp. 64-79

Author(s):

T.A. Shatilina ◽

◽

G.Sh. Tsitsiashvili ◽

T.V. Radchenkova ◽

◽

...

Keyword(s):

Air Temperature ◽

Geopotential Height ◽

Sea Of Okhotsk ◽

Small Neighborhood ◽

Surface Air Temperature ◽

Major Axis ◽

Eastern Coast ◽

Study Region ◽

Extreme Surface ◽

The Sea Of Okhotsk

The field of Н500 geopotential height over the central part of the second natural synoptic region in January during 1950–2019 is analysed to determine regime characteristics of the Okhotsk tropospheric cyclone and its role in the formation of air temperature anomalies over the eastern coast of Asia. A mechanism of occurrence of extreme surface air temperatures using this technique is presented. Extremely low air temperature in the area of the minimum and related deep through are formed during the years when the Н500 minimum is localized over the Sea of Okhotsk. A methodology for constructing ellipses approximating the Н500 level lines in a small neighborhood of the Н500 minimum is developed, the ellipse characteristics are calculated, and their relation to the tropospheric cyclone evolution is analysed. The characteristics of the ellipses constructed in the neighborhood of the geopotential height minimum outside the Sea of Okhotsk significantly differ from those of the ellipses over the Sea of Okhotsk. A high compression of the ellipses towards the major axis is reported when the Far Eastern through intensity is reduced. In this case, an outflow of warm oceanic air masses to the Sea of Okhotsk is observed. The location of the Н500 minimum and the characteristics of the ellipses located within the center circle may be used to explain reasons for dramatic changes in air temperature in the study region. Keywords: Оkhotsk tropospheric cyclone, Н500 minima centers, extreme surface air temperature, ellipse characteristics

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Roles of chemistry modification for laser textured metal alloys to achieve extreme surface wetting behaviors

Materials & Design ◽

10.1016/j.matdes.2020.108744 ◽

2020 ◽

Vol 192 ◽

pp. 108744 ◽

Cited By ~ 4

Author(s):

Avik Samanta ◽

Qinghua Wang ◽

Scott K. Shaw ◽

Hongtao Ding

Keyword(s):

Metal Alloys ◽

Surface Wetting ◽

Extreme Surface ◽

Wetting Behaviors

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Extreme surface propensity of halide ions in water

Nature Communications ◽

10.1038/ncomms5083 ◽

2014 ◽

Vol 5 (1) ◽

Cited By ~ 60

Author(s):

Lukasz Piatkowski ◽

Zhen Zhang ◽

Ellen H. G. Backus ◽

Huib J. Bakker ◽

Mischa Bonn

Keyword(s):

Halide Ions ◽

Extreme Surface

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Spatiotemporal dynamics of land development intensity and summertime extreme surface urban heat island effect in Greater Shanghai (1990-2017)

10.5194/egusphere-egu2020-21923 ◽

2020 ◽

Author(s):

Hao Zhang ◽

Xiao-yan Dai

Keyword(s):

Urban Heat Island ◽

Land Development ◽

Spatiotemporal Dynamics ◽

Policy Implications ◽

Heat Island ◽

Extreme Surface ◽

Evolutionary Pattern ◽

Urban Periphery ◽

Urban Heat ◽

Surface Urban Heat Island

Greater Shanghai, one of China&#8217;s top megacities, is susceptible to extreme heat events during the summer. This study investigated the spatiotemporal dynamics of land development intensity and its influence on summertime extreme surface urban heat island (SUHI) effect in Greater Shanghai, during 1990 and 2017. Driven by the robust economic development and population growth, the formation of Greater Shanghai has dramatically changed from a traditionally compact city to an explosively urbanizing region in 1990&#8211;2017. The results revealed an overall increase in regional LDI of Greater Shanghai in the loss of cropland and water bodies. Simultaneously, the intensified SUHI effect was measured by the increasing relative SUHI intensity (from 1.81&#8451; in 1990 to 3.16&#8451; in 2017) and magnitude (from 306.80 km2 in 1990 to 1570.56 km2 in 2017). The urban-rural gradient analysis based on centric buffers and the representative transects further revealed the spatiotemporal heterogeneity of LDI and its linkage with the evolutionary pattern of the SUHI effect. As indicated, the areal extent of downtown Shanghai within the 0&#8211;15 km buffer increased by 201.70 km2 in 1990&#8211;2017. However, its stably decreasing trends in LDI and associated SUHI effect were observed across the study period. In contrast, the urban periphery and exurban area, which attracted huge investment to develop the infrastructure required for population resettlement and the industrial restructure, experienced a dramatic increase in 1660.57km2 of newly developed land. Concurrently, the remarkably increases in LDI and associated SUHI effect the urban periphery and exurban area were notable. Finally, focusing on the overall alarming situation of the summertime SUHI effect in Greater Shanghai, policy implications, and practical suggestions towards sustainable land development and UHI mitigation were discussed.&#160; &#160;

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