Observed tidal geomagnetic field variations are due to a combination of electric currents in the ionosphere, ocean, and their induced counterparts. Using these variations to constrain subsurface electrical conductivity in oceanic regions is a promising frontier; however, properly separating the ionospheric and oceanic tidal contributions of the magnetic field is critical for this. We compare semidiurnal lunar tidal magnetic signals (i.e., the signals due to the M-2 tidal mode) estimated from 64 global observatories to physics-based forward models of the ionospheric M-2 magnetic field and the oceanic M-2 magnetic field. At ground level, predicted ionospheric M-2 amplitudes are strongest in the horizontal components, whereas the predicted oceanic amplitudes are strongest in the vertical direction. There is good agreement between the predicted and estimated M-2 phases for the Y component; however, the F and X components experience deviations that may be indicative of unmodeled ionospheric processes or unmodeled coastal effects. Overall, we find that the agreement between the physics-based model predictions and the observations is very encouraging for electromagnetic sensing applications, especially since the predicted ionospheric vertical component is very weak. Plain Language Summary Both Earth's oceans and upper atmosphere produce electric current and electromagnetic ( EM) fields. Tides caused by the gravitational interaction between Earth, the Sun, and Moon create reliable, easily constrained EM signals in both the ocean and upper atmosphere. Geophysicists are interested in using these ocean tidal EM signals to study the electrical conductivity of Earth's interior; however, this requires a solid understanding of the upper atmosphere's contribution to the EM signal. This study uses a physics-based model to estimate the relative EM tidal signals of the ocean versus the upper atmosphere to immediately address this concern. We also compare the model predictions with the EM tidal signals constrained from 64 global observatories. Considering the level of complexity of the upper atmosphere's EM tidal signals, we find remarkable agreement between the observed and modeled EM tidal signals. Some of the discrepancies may be of interest to those in upper atmospheric/space physics because they may be due to unmodeled physical processes. Our results are also very encouraging for geophysicists aiming to use EM tidal signals to study Earth's interior since they suggest a small upper atmosphere contribution to the EM tidal signal generally used.
Wells, K. C.; Millet, D. B.; Bousserez, N.; Henze, D. K.; Griffis, T. J.; Chaliyakunnel, S.; Dlugokencky, E. J.; Saikawa, E.; Xiang, G.; Prinn, R. G.; O'Doherty, S.; Young, D.; Weiss, R. F.; Dutton, G. S.; Elkins, J. W.; Krummel, P. B.; Langenfelds, R.; Steele, L. P.;
Published Date:
2018
Source:
Atmospheric Chemistry and Physics, 18(2), 735-756.
Description:
We present top-down constraints on global monthly N2O emissions for 2011 from a multi-inversion approach and an ensemble of surface observations. The inversions employ the GEOS-Chem adjoint and an array of aggregation strategies to test how well curr...
Raczka, B.; Biraud, S. C.; Ehleringer, J. R.; Lai, C. T.; Miller, J. B.; Pataki, D. E.; Saleska, S. R.; Torn, M. S.; Vaughn, B. H.; Wehr, R.; Bowling, D. R.;
Published Date:
2017
Source:
Journal of Geophysical Research-Biogeosciences, 122(8), 1969-1987.
Description:
The seasonal pattern of the carbon isotope content (delta C-13) of atmospheric CO2 depends on local and nonlocal land-atmosphere exchange and atmospheric transport. Previous studies suggested that the delta C-13 of the net land-atmosphere CO2 flux (d...
Journal of Geophysical Research-Atmospheres, 123(15), 7950-7973.
Description:
In this study, we analyze a set of agroclimatological indices across West Africa and assess their projected changes for the future. We apply the regional climate model CCLM (COnsortium for Small-scale MOdelling in CLimate Mode) with a high spatial re...
Kenagy, H. S.; Sparks, T. L.; Ebben, C. J.; Wooldrige, P. J.; Lopez-Hilfiker, F. D.; Lee, B. H.; Thornton, J. A.; McDuffie, E. E.; Fibiger, D. L.; Brown, S. S.; Montzka, D. D.; Weinheimer, A. J.; Schroder, J. C.; Campuzano-Jost, P.; Day, D. A.; Jimenez, J. L.; Dibb, J. E.; Campos, T.; Shah, V.; Jaegle, L.; Cohen, R. C.;
Published Date:
2018
Source:
Journal of Geophysical Research-Atmospheres, 123(17), 9813-9827.
Description:
Although urban NOx lifetimes have been examined extensively during summertime conditions, wintertime NOx chemistry has been comparatively less studied. We use measurements of NOx and its oxidation products from the aircraft-based WINTER (Wintertime I...
Jarvinen, E.; Ignatius, K.; Nichman, L.; Kristensen, T. B.; Fuchs, C.; Hoyle, C. R.; Hoppel, N.; Corbin, J. C.; Craven, J.; Duplissy, J.; Ehrhart, S.; El Haddad, I.; Frege, C.; Gordon, H.; Jokinen, T.; Kallinger, P.; Kirkby, J.; Kiselev, A.; Naumann, K. H.; Petaja, T.; Pinterich, T.; Prevot, A. S. H.; Saathoff, H.; Schiebel, T.; Sengupta, K.; Simon, M.; Slowik, J. G.; Trostl, J.; Virtanen, A.; Vochezer, P.; Vogt, S.; Wagner, A. C.; Wagner, R.; Williamson, C.; Winkler, P. M.; Yan, C.; Baltensperger, U.; Donahue, N. M.; Flagan, R. C.; Gallagher, M.; Hansel, A.; Kulmala, M.; Stratmann, F.; Worsnop, D. R.; Mohler, O.; Leisner, T.; Schnaiter, M.;
Published Date:
2016
Source:
Atmospheric Chemistry and Physics, 16(7), 4423-4438.
Description:
Under certain conditions, secondary organic aerosol (SOA) particles can exist in the atmosphere in an amorphous solid or semi-solid state. To determine their relevance to processes such as ice nucleation or chemistry occurring within particles requir...
Butler, R.; Palmer, P. I.; Feng, L.; Andrews, S. J.; Atlas, E. L.; Carpenter, L. J.; Donets, V.; Harris, N. R. P.; Montzka, S. A.; Pan, L. L.; Salawitch, R. J.; Schauffler, S. M.;
Published Date:
2018
Source:
Atmospheric Chemistry and Physics, 18(17), 13135-13153.
Description:
We use the GEOS-Chem global 3-D atmospheric chemistry transport model to interpret atmospheric observations of bromoform (CHBr3) and dibromomethane (CH2Br2) collected during the CAST and CONTRAST aircraft measurement campaigns over the western Pacifi...
Fried, A.; Barth, M. C.; Bela, M.; Weibring, P.; Richter, D.; Walega, J.; Li, Y.; Pickering, K.; Apel, E.; Hornbrook, R.; Hills, A.; Riemer, D. D.; Blake, N.; Blake, D. R.; Schroeder, J. R.; Luo, Z. J.; Crawford, J. H.; Olson, J.; Rutledge, S.; Betten, D.; Biggerstaff, M. I.; Diskin, G. S.; Sachse, G.; Campos, T.; Flocke, F.; Weinheimer, A.; Cantrell, C.; Pollack, I.; Peischl, J.; Froyd, K.; Wisthaler, A.; Mikoviny, T.; Woods, S.;
Published Date:
2016
Source:
Journal of Geophysical Research-Atmospheres, 121(12), 7430-7460.
Description:
We have developed semi-independent methods for determining CH2O scavenging efficiencies (SEs) during strong midlatitude convection over the western, south-central Great Plains, and southeastern regions of the United States during the 2012 Deep Convec...
Janssens-Maenhout, G.; Crippa, M.; Guizzardi, D.; Dentener, F.; Muntean, M.; Pouliot, G.; Keating, T.; Zhang, Q.; Kurokawa, J.; Wankmuller, R.; van der Gon, H. D.; Kuenen, J. J. P.; Klimont, Z.; Frost, G.; Darras, S.; Koffi, B.; Li, M.;
Published Date:
2015
Source:
Atmospheric Chemistry and Physics, 15(19), 11411-11432.
Description:
The mandate of the Task Force Hemispheric Transport of Air Pollution (TF HTAP) under the Convention on Long-Range Transboundary Air Pollution (CLRTAP) is to improve the scientific understanding of the intercontinental air pollution transport, to quan...
Brown, S. S.; Dube, W. P.; Tham, Y. J.; Zha, Q. Z.; Xue, L. K.; Poon, S.; Wang, Z.; Blake, D. R.; Tsui, W.; Parrish, D. D.; Wang, T.;
Published Date:
2016
Source:
Journal of Geophysical Research-Atmospheres, 121(5), 2457-2475.
Description:
Nighttime reactions of nitrogen oxides influence ozone, volatile organic compounds, and aerosol and are thus important to the understanding of regional air quality. Despite large emissions and rapid recent growth of nitrogen oxide concentrations, the...
Kim, J.; Johnson, L. E.; Cifelli, R.; Choi, J.; Chandrasekar, V.;
Published Date:
2018
Source:
Water, 10(7), 21.
Description:
Soil moisture retention (SMR) capacity plays a key role in estimating the direct runoff when a multi-pulse storm event occurs. It is very important to know how much SMR will be recovered during the intervals of no rain of a multi-pulse storm. This st...
Fairall, C. W.; Matrosov, S. Y.; Williams, C. R.; Walsh, E. J.;
Published Date:
2018
Source:
Journal of Atmospheric and Oceanic Technology, 35(3), 593-608.
Description:
The NOAA W-band radar was deployed on a P-3 aircraft during a study of storm fronts off the U.S. West Coast in 2015 in the second CalWater (CalWater-2) field program. This paper presents an analysis of measured equivalent radar reflectivity factor Z(...
A 4-year record of aerosol size and hygroscopic growth factor distributions measured at the Department of Energy's Southern Great Plains (SGP) site in Oklahoma, U.S. were used to estimate supersaturation (S)-dependent cloud condensation nuclei concen...
Mahoney, K.; Swales, D.; Mueller, M. J.; Alexander, M.; Hughes, M.; Malloy, K.;
Published Date:
2018
Source:
Journal of Climate, 31(16), 6281-6297.
Description:
Atmospheric rivers (ARs) are well-known producers of precipitation along the U.S. West Coast. Depending on their intensity, orientation, and location of landfall, some ARs penetrate inland and cause heavy rainfall and flooding hundreds of miles from ...
Dimdore-Miles, O. B.; Palmer, P. I.; Bruhwiler, L. P.;
Published Date:
2018
Source:
Atmospheric Chemistry and Physics, 18(24), 17895-17907.
Description:
We consider the utility of the annual inter-polar difference (IPD) as a metric for changes in Arctic emissions of methane (CH4). The IPD has been previously defined as the difference between weighted annual means of CH4 mole fraction data collected a...
Sea surface temperature anomalies (SSTA) in portions of the extratropics are known to recur from one winter to the next without persisting through the intervening summer. Previous studies identified only a limited number of midlatitude regions where ...
Richardson, K.; Asmutis-Silvia, R.; Drinkwin, J.; Gilardi, K. V. K.; Giskes, I.; Jones, G.; O'Brien, K.; Pragnell-Raasch, H.; Ludwig, L.; Antonelis, K.; Barco, S.; Henry, A.; Knowlton, A.; Landry, S.; Mattila, D.; MacDonald, K.; Moore, M.; Morgan, J.; Robbins, J.; van der Hoop, J.; Hogan, E.;
Published Date:
2019
Source:
Marine Pollution Bulletin, 138, 222-229.
Description:
Abandoned, lost or discarded fishing gear (ALDFG) comprises a significant amount of global marine debris, with diverse impacts to marine environments, wildlife, and the fishing industry. Building evidence on ALDFG is critical to holistically understa...
Smith, M.; Stammerjohn, S.; Persson, O.; Rainville, L.; Liu, G. Q.; Perrie, W.; Robertson, R.; Jackson, J.; Thomson, J.;
Published Date:
2018
Source:
Journal of Geophysical Research-Oceans, 123(5), 3164-3185.
Description:
High-resolution measurements of the air-ice-ocean system during an October 2015 event in the Beaufort Sea demonstrate how stored ocean heat can be released to temporarily reverse seasonal ice advance. Strong on-ice winds over a vast fetch caused mixi...
Chakraborty, A.; Ervens, B.; Gupta, T.; Tripathi, S. N.;
Published Date:
2016
Source:
Journal of Geophysical Research-Atmospheres, 121(8), 4317-4332.
Description:
Size-resolved fog water samples were collected in two consecutive winters at Kanpur, a heavily polluted urban area of India. Samples were analyzed by an aerosol mass spectrometer after drying and directly in other instruments. Residues of fine fog dr...
Kim, P. S.; Jacob, D. J.; Fisher, J. A.; Travis, K.; Yu, K.; Zhu, L.; Yantosca, R. M.; Sulprizio, M. P.; Jimenez, J. L.; Campuzano-Jost, P.; Froyd, K. D.; Liao, J.; Hair, J. W.; Fenn, M. A.; Butler, C. F.; Wagner, N. L.; Gordon, T. D.; Welti, A.; Wennberg, P. O.; Crounse, J. D.; St. Clair, J. M.; Teng, A. P.; Millet, D. B.; Schwarz, J. P.; Markovic, M. Z.; Perring, A. E.;
Heiblum, R. H.; Altaratz, O.; Koren, I.; Feingold, G.; Kostinski, A. B.; Khain, A. P.; Ovchinnikov, M.; Fredj, E.; Dagan, G.; Pinto, L.; Yaish, R.; Chen, Q.;
Published Date:
2016
Source:
Journal of Geophysical Research-Atmospheres, 121(11), 6336-6355.
Description:
We study the evolution of warm convective cloud fields using large eddy simulations of continental and trade cumulus. Individual clouds are tracked a posteriori from formation to dissipation using a 3-D cloud-tracking algorithm, and results are prese...
Grayver, A. V.; Schnepf, N. R.; Kuvshinov, A. V.; Sabaka, T. J.; Manoj, C.; Olsen, N.;
Published Date:
2016
Source:
Science Advances, 2(9), e1600798.
Series:
CIRES (Cooperative Institute for Research in Environmental Sciences)
Description:
The tidal flow of electrically conductive oceans through the geomagnetic field results in the generation of secondary magnetic signals, which provide information on the subsurface structure. Data from the new generation of satellites were shown to co...
Data-based modeling of the magnetic field originating in the Earth's ionosphere is challenging due to the multiple timescales involved and the small spatial scales of some of the current systems, especially the equatorial electrojet (EEJ) that flows ...
Journal of Geophysical Research-Space Physics, 121(7), 7226-7237.
Description:
Using 2years of magnetic field measurements from the Swarm constellation, we present a detailed study of the equatorial electrojet (EEJ) and its longitudinal gradient (EEJ). This study represents for the first time the tidal characteristics derived f...