The effect of the quasi-biennial oscillation on the Madden-Julian oscillation in the Met Office Unified Model Global Ocean Mixed Layer configuration

Using multi-decadal simulations, we investigate the relationship between the Quasi-Biennial Oscillation (QBO) and the Madden–Julian Oscillation (MJO) in the Global Ocean Mixed Layer Configuration of the Met Office Unified Model (MetUM-GOML1) at two horizontal resolutions (approximately 200 km and 90 km at the equator). MetUM-GOML1 produces a weak and insignificant correlation between QBO winds and mean MJO amplitude in boreal winter, in contrast to the significant anti-correlation in reanalysis. While reanalysis shows the easterly QBO favors stronger Maritime Continent MJO activity, MetUM-GOML1 displays stronger West Pacific MJO activity. The biased QBO-MJO relationship in MetUM-GOML1 may be due to weak QBO-induced temperature anomalies in the tropical tropopause layer, or to errors in MJO vertical structure

Radiative Energy Budget Studies Using Observations from the Earth Radiation Budget Experiment (ERBE)

Our research activities under this NASA grant have focused on two broad topics associated with the Earth Radiation Budget Experiment (ERBE): (1) the role of clouds and the surface in modifying the radiative balance; and (2) the spatial and temporal variability of the earth's radiation budget. Each of these broad topics is discussed separately in the text that follows. The major points of the thesis are summarized in section 3 of this report. Other dissertation focuses on deriving the radiation budget over the TOGA COARE region

Posttraumatic stress symptoms and mental health services utilization in adolescents with social anxiety disorder and experiences of victimization

Recent findings from studies on adults show similarities between social anxiety disorder (SAD) and posttraumatic stress in the form of recurrent memories and intrusive and distressing images of earlier aversive events. Further, treatment models for SAD in adults have been successfully developed by using transdiagnostic knowledge on posttraumatic stress symptoms (PTSS). Studies on adolescents are though missing. The present study aimed at exploring the association between PTSS and SAD in Swedish adolescents. A second aim was to study mental health services utilization in relation to these conditions. A total of 5,960 high-school students participated and reported on SAD, life time victimization, PTSS and mental health service utilization. Socially anxious adolescents reported significantly higher levels of PTSS than adolescents not reporting SAD and this difference was seen in victimized as well as non-victimized subjects. Contact with a school counselor was the most common mental health service utilization in subjects with SAD and those with elevated PTSS. In the prediction of contact with a CAP-clinic, significant odds ratios were found for a condition of SAD and elevated PTSS (OR = 4.88, 95 % CI = 3.53–6.73) but not for SAD only. Screening of PTSS in adolescents with SAD is recommended. The service of school counselors is important in detecting and helping young people with SAD and elevated PTSS. Clinical studies on SAD and PTSS in adolescents could aid in modifying treatment models for SAD

Infant responses to symmetrical and asymmetrical looming pathways

When objects approach an observer, they can result in either a collision (e.g., a hit) or a non-collision (e.g., a miss). Such objects can also travel on different paths of approach. On a symmetrical path, an object starts in front of the observer but on an asymmetrical path, it starts from either the left or the right. This study examined the eye blink response of 4- to 5-month-old infants' to determine if they perceive collision from non-collision on different paths of approach. The results indicated that objects on a collision path led to more blinking than those on a non-collision path, symmetrical paths produced greater blinking responses than asymmetrical paths, and asymmetrical paths where the object crossed in front of the observer's line of sight produced more blinking than those that did not. These findings suggest that type of contact, and path of approach influence infant's perception of collision.M.A

The Effects of Motor Constraints on Infant Search Behaviour

Two studies investigated the effects of various motor constraints of reaching on infants’ search performance on the A-not-B task. These studies were motivated by the idea that motor memories for reaching lead to A-not-B errors. The 2 motor constraints that were evaluated included barriers that blocked the path of the hand and hand-use preferences. Each of these motor constraints was examined separately. In Experiment 1, infants (N = 40, 20 8-month olds, 20 16-month olds) were given the A-not-B task twice. One condition was analogous to the traditional A-not-B task (i.e., using 2 hiding locations) and the other was modified such that a barrier (i.e., an opaque screen) blocked the infants’ reaching path of location A on A trials only. On A trials, all infants searched correctly less often when a barrier was present, and younger infants searched correctly less often than older infants. On B trials, younger infants made more errors in the no barrier condition, whereas older infants did not show any significant difference in B trial performance across conditions. In Experiment 2, infants (N = 51) completed an adapted handedness test (Michel, Ovrut, & Harkins, 1985) followed by a modified A-not-B task. The test assessed infants’ hand-use preferences for reaching, which was used to group infants into their respective preference group (i.e., consistent or inconsistent). Infants with a consistent preference were randomly assigned to a hiding side group (i.e., A on preferred side or A on non-preferred side). Infants searched correctly more often when hiding side was congruent with their preferred reaching hand, and older infants searched correctly more often than younger infants. On the B trial, neither age nor hiding side affected the production of the A-not-B error. Collectively, these studies present data that address the theory that motor memories for reaching are the cause for the production of A-not-B error. These studies provide novel evidence that motor memories for reaching are present in infants aged 8- and 16-months, and that motor memories can influence the production of such errors in certain A-not-B contexts. Implications and directions for future research are also discussed.Ph

Revelations about tropical cyclones from A-train satellite data: the effect of environmental aerosols on tropical cyclone formation, and the origin of ozone in the eyes of mature tropical cyclones

Prior studies have shown that high levels of aerosols in the environment of convective clouds can cause the convection to become more vigorous through a five step process. Tropical cyclones (TCs) start as clusters of convective clouds; intense convection is important for the development of the cluster into a TC. This study tests the hypothesis that high aerosol content in the vicinity of a convective cloud cluster increases the chances that the cluster will develop into a TC by invigorating its convection. This study centers on 63 clusters that developed into TCs (developers) and 98 clusters that dissipated before becoming a TC (nondevelopers). Using observations from a satellite associated with the “A-train” group of satellites, it was established that the average aerosol content surrounding developers was significantly higher than that surrounding nondevelopers. Furthermore, A-train measurements were used to establish that each of the five steps associated with invigoration of convection by aerosols were more prominent in the developers than in the nondevelopers. Altogether, the data suggests convective cloud clusters embedded in regions with elevated aerosols may have a greater likelihood of developing into a TC because the aerosols may invigorate their convection.A-train satellite data are also used to investigate ozone levels in the eyes of mature TCs. Several previous studies have found evidence of high ozone levels inside TC eyes. Explanations for the elevated ozone involve intrusion of ozone-rich stratospheric air downward into the eye or a lower tropopause over the eye. Other studies have found no evidence of elevated ozone in TC eyes. However, ozone measurements from both types of studies (evidence and no evidence of elevated ozone) were less than optimal. This study analyses seven mature TCs with satellite overpasses directly over the eye – an optimal situation for ozone measurement. The results indicate TCs can have very high ozone concentrations in the eyewall. This suggests eyewall lighting produces the ozone. The data also suggest the elevated ozone content in the eyewall is often transported into the eye. Thus TC eyes can contain elevated ozone levels, but the source appears to be the eyewall, not the stratosphere

The Effects of Motor Constraints on Infant Search Behaviour

Two studies investigated the effects of various motor constraints of reaching on infants’ search performance on the A-not-B task. These studies were motivated by the idea that motor memories for reaching lead to A-not-B errors. The 2 motor constraints that were evaluated included barriers that blocked the path of the hand and hand-use preferences. Each of these motor constraints was examined separately. In Experiment 1, infants (N = 40, 20 8-month olds, 20 16-month olds) were given the A-not-B task twice. One condition was analogous to the traditional A-not-B task (i.e., using 2 hiding locations) and the other was modified such that a barrier (i.e., an opaque screen) blocked the infants’ reaching path of location A on A trials only. On A trials, all infants searched correctly less often when a barrier was present, and younger infants searched correctly less often than older infants. On B trials, younger infants made more errors in the no barrier condition, whereas older infants did not show any significant difference in B trial performance across conditions. In Experiment 2, infants (N = 51) completed an adapted handedness test (Michel, Ovrut, & Harkins, 1985) followed by a modified A-not-B task. The test assessed infants’ hand-use preferences for reaching, which was used to group infants into their respective preference group (i.e., consistent or inconsistent). Infants with a consistent preference were randomly assigned to a hiding side group (i.e., A on preferred side or A on non-preferred side). Infants searched correctly more often when hiding side was congruent with their preferred reaching hand, and older infants searched correctly more often than younger infants. On the B trial, neither age nor hiding side affected the production of the A-not-B error. Collectively, these studies present data that address the theory that motor memories for reaching are the cause for the production of A-not-B error. These studies provide novel evidence that motor memories for reaching are present in infants aged 8- and 16-months, and that motor memories can influence the production of such errors in certain A-not-B contexts. Implications and directions for future research are also discussed.Ph