Data from ground-based ozone (O3) vertical profiling platforms operated during the FRAPPE/DISCOVER-AQ campaigns in summer 2014 were used to characterize key processes responsible for establishing O3 profile development in the boundary layer in the Northern Colorado Front Range. Morning mixing from the upper boundary layer and lower free troposphere into the lower boundary layer was the key process establishing the mid-morning boundary layer O3 mixing ratio. Photochemical O3 production throughout the boundary layer builds on the mid-morning profile. From late morning to mid-afternoon the continuing O3 increase was nearly uniform through the depth of the profile measured by the tethersonde (~400 m). Ozonesondes flown on a near daily schedule over a four week period with multiple profiles on a number of days captured the full 1500 to 2000 m vertical extent of O3 enhancements in the mixed boundary layer confirming O3 production throughout the entire boundary layer. Continuous O3 measurements from the Boulder Atmospheric Observatory (BAO) tall tower at 6 m and 300 m showed hourly O3 at the 6 m level ≥75 ppb on 15% of the days. The diurnal variation on these days followed a pattern similar to that seen in the tethersonde profiles. The association of high O3 days at the BAO tower with transport from sectors with intense oil and natural gas production toward the northeast suggests emissions from this industry were an important source of O3 precursors and are crucial in producing peak O3 events in the NCFR. Higher elevation locations to the west of the NCFR plains regularly experience higher O3 values than those in the lower elevation NCFR locations. Exposure of populations in these areas is not captured by the current regulatory network, and likely underestimated in population O3 exposure assessments.
Thompson, Elizabeth J.; Moum, James N.; Fairall, Christopher W.; Rutledge, Steven A.;
Published Date:
2019
Source:
Journal of Geophysical Research: Oceans,;
124, 897–924;
Description:
Stratification of the upper few meters of the ocean limits the penetration depth of wind mixing and the vertical distribution of atmospheric fluxes. Significant density stratification at depths ≤ 5 m was observed in 38% of a 2‐month data set from...
We used data from 333 continuous Global Positioning System stations, including 26 stations installed in 2006–2007 as part of a collaborative EarthScope experiment, to investigate how deformation is distributed near the Rio Grande Rift. Our previous...
Observations of shallow fault creep reveal increasingly complex time‐dependent slip histories that include quasi‐steady creep and triggered as well as spontaneous accelerated slip events. Here we report a recent slow slip event on the southern Sa...
Ryu, Y. H.; Hodzic, A.; Descombes, G.; Hu, M.; Barre, J.;
Published Date:
2019
Source:
Journal of Geophysical Research: Atmospheres, 124, 13576-13592
Description:
Accuracy of cloud predictions in numerical weather models can considerably impact ozone (O-3) forecast skill. This study assesses the benefits in surface O-3 predictions of using the Rapid Refresh (RAP) forecasting system that assimilates clouds as w...
Thompson, Anne M.; Smit, Herman G. J.; Witte, Jacquelyn C.; Stauffer, Ryan M.; Johnson, Bryan J.; Morris, Gary; von der Gathen, Peter; Van Malderen, Roeland; Davies, Jonathan; Allaart, Ankie Piters Marc; Posny, Françoise; Kivi, Rigel; Cullis, Patrick; Nguyen, Thi Hoang Anh; Corrales, Ernesto; Machinini, Tshidi; da Silva, Francisco R.; Paiman, George; Thiong’o, Kennedy; Zainal, Zamuna; Brothers, George B.; Wolff, Katherine R.; Nakano, Tatsumi; Stübi, Rene; Romanens, Gonzague; Coetzee, Gert J. R.; Diaz, Jorge A.; Mitro, Sukarni; Mohamad, Maznorizan; Ogino, Shin-Ya;
Published Date:
2019
Source:
Bull. Amer. Meteor. Soc. (2019) 100 (1): 155–171.
Description:
The ozonesonde is a small balloon-borne instrument that is attached to a standard radiosonde to measure profiles of ozone from the surface to 35 km with ∼100-m vertical resolution. Ozonesonde data constitute a mainstay of satellite calibration and ...
White, Allen B.; Moore, Benjamin J.; Gottas, Daniel J.; Neiman, Paul J.;
Published Date:
2019
Source:
Bull. Amer. Meteor. Soc. (2019) 100 (1): 55–70.
Description:
During winter 2016/17, California experienced numerous heavy precipitation events linked to land-falling atmospheric rivers (ARs) that filled reservoirs and ended a severe, multiyear drought. These events also caused floods, mudslides, and debris flo...
Yu, P. F.; Froyd, K. D.; Portmann, R. W.; Toon, O. B.; Freitas, S. R.; Bardeen, C. G.; Brock, C.; Fan, T. Y.; Gao, R. S.; Katich, J. M.; Kupc, A.; Liu, S.; Maloney, C.; Murphy, D. M.; Rosenlof, K. H.; Schill, G.; Schwarz, J. P.; Williamson, C.;
Published Date:
2019
Source:
Geophysical Research Letters, 46, 1061-1069.
Description:
Convective systems dominate the vertical transport of aerosols and trace gases. The most recent in situ aerosol measurements presented here show that the concentrations of primary aerosols including sea salt and black carbon drop by factors of 10 to ...
An intensive coordinated airborne and ground-based measurement study was conducted in the Fayetteville Shale in northwestern Arkansas during September and October 2015 to compare and explain potential discrepancies between top-down and bottom-up esti...
Yang, H.; Waugh, D. W.; Orbe, C.; Patra, P. K.; Jockel, P.; Lamarque, J. F.; Tilmes, S.; Kinnison, D.; Elkins, J. W.; Dlugokencky, E. J.;
Published Date:
2019
Source:
Geophysical Research Letters, 46, 1113-1120.
Description:
Two recent studies using sulfur hexafluoride (SF6) observations to evaluate interhemispheric transport in two different ensembles of atmospheric chemistry models reached different conclusions on model performance. We show here that the different conc...
Reitman, Nadine G.; Mueller, Karl J.; Tucker, Gregory E.; Gold, Ryan D.; Briggs, Richard W.; Barnhart, Katherine R.;
Published Date:
2019
Source:
JGR Solid Earth (2019). 124(12): 13427-13451
Description:
Slip distribution, slip rate, and slip per event for strike‐slip faults are commonly determined by correlating offset stream channels—under the assumption that they record seismic slip—but offset channels are formed by the interplay of tectonic...
Stillwell, Robert A.; Neely III, Ryan R.; Thayer, Jeffrey P.; Walden, Von P.; Shupe, Matthew D.; Miller, Nathaniel B.;
Published Date:
2019
Source:
Journal of Geophysical Research: Atmospheres, 124, 12141-12156
Description:
Ice crystals commonly adopt a horizontal orientation under certain aerodynamic and electrodynamic conditions that occur in the atmosphere. While the radiative impact of horizontally oriented ice crystals (HOIC) has been theoretically studied with res...
The yields of the six declared underground nuclear tests at the North Korean test site are estimated using high‐frequency teleseismic P wave amplitude modeling and waveform equalization of short‐period teleseismic P waves and regional Pn signals....
The cryosphere, which comprises a large portion of Earth’s surface, is rapidly changing as a consequence of global climate change. Ice, snow, and frozen ground in the polar and alpine regions of the planet are known to directly impact atmospheric c...
Mazzotti, Giulia; Currier, William Ryan; Deems, Jeffrey S.; Pflug, Justin M.; Lundquist, Jessica D.; Jonas, Tobias;
Published Date:
2019
Source:
Water Resources Research, 55(7): 6198–6216
Description:
The retrieval of detailed, co‐located snow depth and canopy cover information from airborne lidar has advanced our understanding of links between forest snow distribution and canopy structure. In this study, we present two recent high‐resolution ...
Serreze, Mark C.; Barrett, Andrew P.; Crawford, Alex D.; Woodgate, Rebecca A.;
Published Date:
2019
Source:
Journal of Geophysical Research: Oceans, 124, 9317–9337
Description:
The Bering Strait oceanic heat transport influences seasonal sea ice retreat and advance in the Chukchi Sea. Monitored since 1990, it depends on water temperature and factors controlling the volume transport, assumed to be local winds in the strait a...
The Eastern Cordillera of Colombia, in the northern Andes, is an example of an orogen in which Mesozoic basins were compressed during the Cenozoic, forming a ~2,500‐m‐high plateau in its northern portion. Significant shortening and crustal thicke...
Yarce, J.; Sheehan, A. F.; Nakai, J. S.; Schwartz, S. Y.; Mochizuki, K.; Savage, M. K.; Wallace, L. M.; Henrys, S. A.; Webb, S. C.; Ito, Y.; Abercrombie, R. E.; Fry, B.; Shaddox, H.; Todd, E. K.;
Published Date:
2019
Source:
JGR Solid Earth (2019). 124(5): 4751-5766
Description:
In 2014–2015, the Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip experiment deployed seafloor absolute pressure gauges and ocean bottom seismometers directly above a large slow slip event, allowing examination of the relationship betw...
We propose a time series modeling approach based on nonlinear dynamical systems to recover the underlying dynamics and predictability of streamflow and to produce projections with identifiable skill. First, a wavelet spectral analysis is performed on...
Morrison, A. L.; Kay, J. E.; Frey, W. R.; Chepfer, H.; Guzman, R.;
Published Date:
2019
Source:
Journal of Geophysical Research: Atmospheres, 124, 1003-1020
Description:
Over the next century, the Arctic is projected to become seasonally sea ice‐free. Assessing feedback between clouds and sea ice as the Arctic loses sea ice cover is important because of clouds' radiative impacts on the Arctic surface. Here we inves...
Takahashi, H.; Lebsock, M. D.; Richardson, M.; Marchand, R.; Kay, J. E.;
Published Date:
2019
Source:
Journal of Geophysical Research: Atmospheres, 124, 7270-7285
Description:
Cloud feedbacks remain the largest source of uncertainty in future climate predictions. Simulations robustly project an increase in cloud height, which is supported by some observational evidence. However, how much of this increasing trend is due to ...
Tarasick, D.; Galbally, I. E.; Cooper, O. R.; Schultz, M. G.; Ancellet, G.; Leblanc, T.; Wallington, T. J.; Ziemke, J.; Liu, X.; Steinbacher, M.; Staehelin, J.; Vigouroux, C.; Hannigan, J. W.; Garcia, O.; Foret, G.; Zanis, P.; Weatherhead, E.; Petropavlovskikh, I.; Worden, H.; Osman, M.; Liu, J.; Chang, K. L.; Gaudel, A.; Lin, M. Y.; Granados-Munoz, M.; Thompson, A. M.; Oltmans, S. J.; Cuesta, J.; Dufour, G.; Thouret, V.; Hassler, B.; Trickl, T.; Neu, J. L.;
Published Date:
2019
Source:
Elem Sci Anth, 7(1), p.39.
Description:
From the earliest observations of ozone in the lower atmosphere in the 19th century, both measurement methods and the portion of the globe observed have evolved and changed. These methods have different uncertainties and biases, and the data records ...