scholarly journals Using TES retrievals to investigate PAN in North American biomass burning plumes

2018 ◽  
Vol 18 (8) ◽  
pp. 5639-5653 ◽  
Author(s):  
Emily V. Fischer ◽  
Liye Zhu ◽  
Vivienne H. Payne ◽  
John R. Worden ◽  
Zhe Jiang ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Colorado Front Range ◽  
Ozone Production ◽  
Hazard Mapping ◽  
Front Range ◽  
Mapping System ◽  
Smoke Plumes ◽  
In Situ Observations

Abstract. Peroxyacyl nitrate (PAN) is a critical atmospheric reservoir for nitrogen oxide radicals, and plays a lead role in their redistribution in the troposphere. We analyze new Tropospheric Emission Spectrometer (TES) PAN observations over North America from July 2006 to July 2009. Using aircraft observations from the Colorado Front Range, we demonstrate that TES can be sensitive to elevated PAN in the boundary layer (∼ 750 hPa) even in the presence of clouds. In situ observations have shown that wildfire emissions can rapidly produce PAN, and PAN decomposition is an important component of ozone production in smoke plumes. We identify smoke-impacted TES PAN retrievals by co-location with NOAA Hazard Mapping System (HMS) smoke plumes. Depending on the year, 15–32 % of cases where elevated PAN is identified in TES observations (retrievals with degrees of freedom (DOF) > 0.6) overlap smoke plumes during July. Of all the retrievals attempted in the July 2006 to July 2009 study period, 18 % is associated with smoke . A case study of smoke transport in July 2007 illustrates that PAN enhancements associated with HMS smoke plumes can be connected to fire complexes, providing evidence that TES is sufficiently sensitive to measure elevated PAN several days downwind of major fires. Using a subset of retrievals with TES 510 hPa carbon monoxide (CO) > 150 ppbv, and multiple estimates of background PAN, we calculate enhancement ratios for tropospheric average PAN relative to CO in smoke-impacted retrievals. Most of the TES-based enhancement ratios fall within the range calculated from in situ measurements.

scholarly journals The Contribution of Fires to TES Observations of Free Tropospheric PAN over North America in July

2017 ◽  
Author(s):  
Emily V. Fischer ◽  
Liye Zhu ◽  
Vivienne H. Payne ◽  
John R. Worden ◽  
Zhe Jiang ◽  
...  
Keyword(s):  
North America ◽  
Colorado Front Range ◽  
Ozone Production ◽  
Hazard Mapping ◽  
Front Range ◽  
Mapping System ◽  
Smoke Plumes ◽  
In Situ Observations

Abstract. Peroxyacetyl nitrate (PAN) is a critical atmospheric reservoir for nitrogen oxide radicals, and it plays a lead role in their redistribution in the troposphere. We analyze new Tropospheric Emission Spectrometer (TES) PAN observations over North America during July 2006 to 2009. Using aircraft observations from the Colorado Front Range, we demonstrate that TES can be sensitive to elevated PAN in the boundary layer even in the presence of clouds. In situ observations have shown that wildfire emissions can rapidly produce PAN, and PAN decomposition is an important component of ozone production in smoke plumes. We identify smoke-impacted TES PAN retrievals by co-location with NOAA Hazard Mapping System (HMS) smoke plumes. We find that 15–32 % of cases where elevated PAN is identified in TES observations (retrievals with DOF > 0.6) overlap smoke plumes. A case study of smoke transport in July 2007 illustrates that PAN enhancements associated with HMS smoke plumes can be connected to fire complexes, providing evidence that TES is sufficiently sensitive to measure elevated PAN several days downwind of major fires. Using a subset of retrievals with TES 510 hPa carbon monoxide (CO) > 150 ppbv, and multiple estimates of background PAN, we calculate enhancement ratios for tropospheric average PAN relative to CO in smoke-impacted retrievals. Most of the TES-based enhancement ratios fall within the range calculated from in situ measurements.

scholarly journals Using stable isotopes of hydrogen to quantify biogenic and thermogenic atmospheric methane sources: A case study from the Colorado Front Range

2016 ◽  
Vol 43 (21) ◽  
pp. 11,462-11,471 ◽  
Author(s):  
Amy Townsend-Small ◽  
E. Claire Botner ◽  
Kristine L. Jimenez ◽  
Jason R. Schroeder ◽  
Nicola J. Blake ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Colorado Front Range ◽  
Front Range ◽  
Atmospheric Methane

scholarly journals The extreme runoff index for flood early warning in Europe

2014 ◽  
Vol 14 (6) ◽  
pp. 1505-1515 ◽  
Author(s):  
L. Alfieri ◽  
F. Pappenberger ◽  
F. Wetterhall
Keyword(s):  
Early Warning ◽  
Input Data ◽  
Weather Forecasting ◽  
Spatial Inhomogeneity ◽  
Optimal Timing ◽  
Numerical Predictions ◽  
In Situ Observations

Abstract. Systems for the early detection of floods over continental and global domains have a key role in providing a quick overview of areas at risk, raise the awareness and prompt higher detail analyses as the events approach. However, the reliability of these systems is prone to spatial inhomogeneity, depending on the quality of the underlying input data and local calibration. This work proposes a simple approach for flood early warning based on ensemble numerical predictions of surface runoff provided by weather forecasting centers. The system is based on a novel indicator, referred to as an extreme runoff index (ERI), which is calculated from the input data through a statistical analysis. It is designed for use in large or poorly gauged domains, as no local knowledge or in situ observations are needed for its setup. Daily runs over 32 months are evaluated against calibrated hydrological simulations for all of Europe. Results show skillful flood early warning capabilities up to a 10-day lead time. A dedicated analysis is performed to investigate the optimal timing of forecasts to maximize the detection of extreme events. A case study for the central European floods of June 2013 is presented and forecasts are compared to the output of a hydro-meteorological ensemble model.

scholarly journals Characterization of ozone production in San Antonio, Texas, using measurements of total peroxy radicals

2019 ◽  
Vol 19 (5) ◽  
pp. 2845-2860 ◽  
Author(s):  
Daniel C. Anderson ◽  
Jessica Pavelec ◽  
Conner Daube ◽  
Scott C. Herndon ◽  
Walter B. Knighton ◽  
...  
Keyword(s):  
San Antonio ◽  
Peroxy Radical ◽  
Ozone Production ◽  
Peroxy Radicals ◽  
Entire Region ◽  
Volatile Organic ◽  
In Situ Observations ◽  
Study Sites

Abstract. Observations of total peroxy radical concentrations ([XO2] ≡ [RO2] + [HO2]) made by the Ethane CHemical AMPlifier (ECHAMP) and concomitant observations of additional trace gases made on board the Aerodyne Mobile Laboratory (AML) during May 2017 were used to characterize ozone production at three sites in the San Antonio, Texas, region. Median daytime [O3] was 48 ppbv at the site downwind of central San Antonio. Higher concentrations of NO and XO2 at the downwind site also led to median daytime ozone production rates (P(O3)) of 4.2 ppbv h−1, a factor of 2 higher than at the two upwind sites. The 95th percentile of P(O3) at the upwind site was 15.1 ppbv h−1, significantly lower than values observed in Houston. In situ observations, as well as satellite retrievals of HCHO and NO2, suggest that the region was predominantly NOx-limited. Only approximately 20 % of observations were in the VOC-limited regime, predominantly before 11:00 EST, when ozone production was low. Biogenic volatile organic compounds (VOCs) comprised 55 % of total OH reactivity at the downwind site, with alkanes and non-biogenic alkenes responsible for less than 10 % of total OH reactivity in the afternoon, when ozone production was highest. To control ozone formation rates at the three study sites effectively, policy efforts should be directed at reducing NOx emissions. Observations in the urban center of San Antonio are needed to determine whether this policy is true for the entire region.

The Lightning and Dual-Polarization Radar Characteristics of Three Hail-Accumulating Thunderstorms

2020 ◽  
Vol 35 (4) ◽  
pp. 1583-1603
Author(s):  
Robinson Wallace ◽  
Katja Friedrich ◽  
Wiebke Deierling ◽  
Evan A. Kalina ◽  
Paul Schlatter
Keyword(s):  
Real Time ◽  
Scientific Community ◽  
Radar Data ◽  
Optimal Combination ◽  
Front Range ◽  
Dual Polarization ◽  
Translation Speed ◽  
Maximum Accumulation ◽  
In Situ Observations

AbstractThunderstorms that produce hail accumulations at the surface can impact residents by obstructing roadways, closing airports, and causing localized flooding from hail-clogged drainages. These storms have recently gained an increased interest within the scientific community. However, differences that are observable in real time between these storms and storms that produce nonimpactful hail accumulations have yet to be documented. Similarly, the characteristics within a single storm that are useful to quantify or predict hail accumulations are not fully understood. This study uses lightning and dual-polarization radar data to characterize hail accumulations from three storms that occurred on the same day along the Colorado–Wyoming Front Range. Each storm’s characteristics are verified against radar-derived hail accumulation maps and in situ observations. The storms differed in maximum accumulation, either producing 22 cm, 7 cm, or no accumulation. The magnitude of surface hail accumulations is found to be dependent on a combination of in-cloud hail production, storm translation speed, and hailstone melting. The optimal combination for substantial hail accumulations is enhanced in-cloud hail production, slow storm speed, and limited hailstone melting. However, during periods of similar in-cloud hail production, lesser accumulations are derived when storm speed and/or hailstone melting, identified by radar presentation, is sufficiently large. These results will aid forecasters in identifying when hail accumulations are occurring in real time.

Variational Data Assimilation for Renewable Wind Energy Predictions: China Inner Mongolia Case Study

2011 ◽  
Vol 383-390 ◽  
pp. 3685-3689 ◽  
Author(s):  
Hai Feng Wang ◽  
Wen Jun Yin ◽  
Meng Zhang ◽  
Jin Dong
Keyword(s):  
Data Assimilation ◽  
Inner Mongolia ◽  
Forecast Error ◽  
Scale Model ◽  
Initial Condition ◽  
Short Term ◽  
In Situ Observations ◽  
Meso Scale

Advanced data assimilation method is used for the short-term wind power forecasting based on a meso-scale model. Considerable forecast error reduction is concluded from a case study in China, where a better resolved high-resolution initial condition is introduced via assimilating various in-situ observations.

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