ALBERT

Description: Abstract Information about population abundance, distribution, and demographic rates are critical for understanding a species’ ecology and for effective conservation and management. To collect data over large spatial and temporal extents for such inferences, especially for species with low densities or wide distributions, citizen science can be an efficient approach. Integrated models have also emerged as an important methodology to estimate population parameters by combining multiple types of data, including citizen science data. We developed a spatially explicit integrated model that combines opportunistically collected presence‐absence (PA) data, commonly collected in citizen science efforts, with systematically collected spatial‐capture‐recapture (SCR) data, which are often limited to small spatial and temporal extents. We conducted single and multi‐season simulations with parameters informed by North American black bear (Ursus americanus) populations, to evaluate the influence of varying amounts of opportunistic PA data collected at larger spatial and temporal extents on the estimation of population–level parameters. Integrating opportunistic PA data increased the precision and accuracy of posterior estimates of abundance, and survival and recruitment rates. In some cases, adding PA locations improved abundance estimates more than increasing PA detection probability. Posterior estimates were as precise and unbiased as when higher quality, but sparse, SCR data were available. We also applied the integrated model to SCR and citizen science PA data collected on black bears in New York, with results consistent with our simulations. Our findings indicate that citizen science in integrated models can be a cost efficient way to improve estimates of population parameters and increase the spatio‐temporal extent of inference. Continued developments with integrated models and citizen science data will offer additional ways to improve our understanding of population structure and demographics. This article is protected by copyright. All rights reserved.

Description: The ocean's western boundary current regions display the greatest rate of twentieth century warming and global climate models project that the accelerated rate of warming will continue with climate change. All existing global climate change projections come from simulations that do not fully resolve either these boundary currents or their eddies. Using an Ocean Eddy-resolving Model (OEM) that captures the dynamics of the East Australian Current (EAC) and its eddies we show the response of the Tasman Sea to climate change differs from what is projected with a coarse resolution Global Climate Model (GCM). With climate change, the OEM projects increased EAC transport with increased eddy activity and an approximately 1° southward latitudinal shift in the point where the EAC separates from the shelf and flows eastward. The OEM increased eddy activity in the Tasman Sea with climate change increases the nutrient supply to the upper ocean and causes an increase in the phytoplankton concentrations and primary productivity by 10% in the oligotrophic waters of the Tasman Sea. The increase in primary productivity is absent in the GCM climate change projection, which projects the region will have a decrease in primary productivity with climate change. Applying the OEM climate change projection for the Tasman Sea to other western boundary current regions suggests the projected intensification of all western boundary currents with climate change should increase eddy activity and provide an important nutrient supply mechanism to counter the increased stratification projected with global warming.

Description: The impact of geomagnetically induced currents (GIC) on the power networks at middle and low latitudes has attracted attention in recent years with the increase of large-scale power networks. In this study, we report the GIC monitored at two low-latitude 500 kV substations of China during the large storm of 17 March 2015. The GIC due to the SSC was much higher than that during the storm main phase. This phenomenon is more likely to happen at low-latitude locations, highlighting the importance of SSC in inducing GIC in low-latitude power networks. Furthermore, we ran a global MHD model to simulate the GIC during this SSC event by using the solar wind observation as input. The model results reproduced the main features of the GIC. The study also indicated that the eastward component of the geoelectric field is dominant for low-latitude locations during the SSC events. Further, topology and electrical parameters of the power grids make significant differences in the GIC levels.

Description: In this paper, the total electron content (TEC) of the global ionosphere map (GIM) is used to detect seismoionospheric anomalies associated with the 12 January 2010 M7 Haiti earthquake, and an ionospheric model is applied to simulate the detected anomalies. The GIM temporal variation shows that the TEC over the epicenter significantly enhances on 11 January 2010, 1 day before the earthquake. The latitude-time-TEC (LTT) plots reveal three anomalies: (1) the northern crest of equatorial ionization anomaly (EIA) moves poleward, (2) the TECs at the epicenter and its conjugate increase, and (3) the TECs at two dense bands in the midlatitude ionosphere of 35°N and 60°S further enhance. The spatial analysis demonstrates that the TEC enhancement anomaly appears specifically and persistently in a small region of the northern epicenter area. The simulation well reproduces the three GIM TEC anomalies, which indicate that the dynamoelectric field of the ionospheric plasma fountain might have been perturbed by seismoelectric signals generated around the epicenter during the earthquake preparation period.

Description: In this paper, concurrent/co-located measurements of seismometers, infrasonic systems, magnetometers, HF-CW (high frequency - continuous wave) Doppler sounding systems, and GPS receivers are employed to detect disturbances triggered by seismic waves of the 11 March 2011 M9.0 Tohoku earthquake. No time delay between co-located infrasonic ( i.e. super long acoustic) waves and seismic waves indicates that the triggered acoustic and/or gravity waves in the atmosphere (or seismo-traveling atmospheric disturbances, STADs) near the Earth's surface can be immediately activated by vertical ground motions. The circle method is used to find the origin and compute the observed horizontal traveling speed of the triggered infrasonic waves. The speed of about 3.3 km/s computed from the arrival time versus the epicentral distance suggests that the infrasonic waves ( i.e. STADs) are mainly induced by the Rayleigh waves. The agreements in the travel time at various heights between the observation and theoretical calculation suggest that the STADs triggered by the vertical motion of ground surface caused by the Tohoku earthquake traveled vertically from the ground to the ionosphere with speed of the sound in the atmosphere over Taiwan.

Description: We present different magnetic field changes in the nightside magnetosphere in response to the interplanetary (IP) shock on 17 December 2007, using multiple spacecraft observations and global MHD simulations. The coexistence of two distinct Bz response regions in the nightside magnetosphere in a single event has been observationally identified for the first time. From the inner magnetosphere to the tail, they are the positive response (Bz increase) and the negative response (Bz decrease). This scenario reasonably agrees with the MHD model prediction. Moreover, the analysis of the response delay time shows that, for the three satellites which observed the negative responses of Bz, the one closest to Earth was the last to respond. This phenomenon can also be understood based on the model prediction that the negative response region develops toward Earth after its formation. In addition, the temporarily enhanced earthward flows in the negative response region, which were suggested to be responsible for the formation of this region by previous model studies, were also supported by the observation. At last, a global view of the Bz response processes in the nightside magnetosphere is presented based on MHD simulations.

Description: We describe our 3-D, time-dependent, MHD solar wind model that we recently modified to include the physics of pickup protons from interstellar neutral hydrogen. The model has a time-dependent lower boundary condition, at 0.1 AU, that is driven by source surface map files through an empirical interface module. We describe the empirical interface and its parameter tuning to maximize model agreement with background (quiet) solar wind observations at ACE. We then give results of a simulation study of the famous Halloween 2003 series of solar events. We began with shock inputs from the Fearless Forecast real-time shock arrival prediction study, and then we iteratively adjusted input shock speeds to obtain agreement between observed and simulated shock arrival times at ACE. We then extended the model grid to 5.5 AU and compared those simulation results with Ulysses observations at 5.2 AU. Next we undertook the more difficult tuning of shock speeds and locations to get matching shock arrival times at both ACE and Ulysses. Then we ran this last case again with neutral hydrogen density set to zero, to identify the effect of pickup ions. We show that the speed of interplanetary shocks propagating from the Sun to Ulysses is reduced by the effects of pickup protons. We plan to make further improvements to the model as we continue our benchmarking process to 10 AU, comparing our results with Cassini observations, and eventually on to 100 AU, comparing our results with Voyager 1 and 2 observations.

Description: Inspired by the fact that spacecraft at geosynchronous orbit may observe an increase or decrease in the magnetic field in the midnight sector caused by interplanetary fast forward shocks (FFS), we perform global MHD simulations of the nightside magnetospheric magnetic field response to interplanetary (IP) shocks. The model reveals that when a FFS sweeps over the magnetosphere, there exist mainly two regions: a positive response region caused by the compressive effect of the shock and a negative response region which is probably associated with the temporary enhancement of earthward convection in the nightside magnetosphere. IP shocks with larger upstream dynamic pressures have a higher probability of producing a decrease in Bz that can be observed in the midnight sector at geosynchronous orbit, and other solar wind parameters such as the interplanetary magnetic field (IMF) Bz and IP shock speed do not seem to increase this probability. Nevertheless, the southward IMF Bz leads to a stronger and larger negative response region, and a higher IP shock speed results in stronger negative and positive response regions. Finally, a statistical survey of nightside geosynchronous Bz response to IP shocks between 1998 and 2005 is conducted to examine these model predictions.

Description: In response to interplanetary (IP) shocks, magnetic field may decrease/increase (negative/positive response) in nightside magnetosphere, while at high latitudes on the ground it has two phase bipolar variations: preliminary impulse(PI) and main impulse (MI). Using global MHD simulations, we investigate the linkage between the MI phase variation on the ground and the magnetospheric negative response to an IP shock. It is revealed that although the two phenomena occur at largely-separated locations, they are physically related and form a response chain. The velocity disturbances near the flanks of the magnetopause cause the magnetic field to decrease, resulting in a dynamo which thus powers the transient field-aligned currents (FACs). These FACs further generates a pair of ionospheric current vortex, leading to MI variations on the ground. Therefore, we report here the intrinsic physically-related chain response of the magnetospheric - and - ground magnetic field to IP shocks, and thus links the magnetospheric sudden impulse (SI) and ground SI together.