The seasonal footprinting mechanism in large ensemble simulations of the second generation Canadian earth system model: uncertainty due to internal climate variability
CLIMATE DYNAMICS
Authors: Chen, Shangfeng; Yu, Bin
Abstract
Previous studies indicated that the wintertime North Pacific Oscillation (NPO) could exert marked impacts on the following winter El Nino-Southern Oscillation (ENSO) via the seasonal footprinting mechanism (SFM). Here, we examine this winter NPO-ENSO relationship in a 50-member ensemble of historical simulations conducted with the Canadian Centre for Climate Modeling and Analysis second generation Canadian Earth System Model (CanESM2) over the period of 1950-2005. The observed NPO pattern, featured by a meridional dipole atmospheric anomaly over the North Pacific, can be well reproduced by all of the 50 ensemble members. The multi-member ensemble (MME) mean can well simulate the observed NPO-ENSO relationship, as well as the SFM process. However, there exists a large spread of the results among the 50 members due to internal climate variability. Internal climate variability influences the winter NPO-ENSO relationship through modulating the subtropical center of the NPO. Specifically, the ensemble members with high NPO-ENSO correlations tend to have strong atmospheric anomalies over the subtropical North Pacific in winter. The atmospheric circulation anomaly brings strong sea surface temperature and precipitation anomalies in the tropical central Pacific and westerly wind anomalies over the tropical western Pacific in the following spring. These anomalies sustain in the following seasons and eventually lead to ENSO events in the following winter.
Postoperative Analgesic Requirement and Pain Perceptions after Nonaerodigestive Head and Neck Surgery
OTOLARYNGOLOGY-HEAD AND NECK SURGERY
Authors: Stephenson, Elizabeth D.; Farzal, Zainab; Jowza, Maryam; Hackman, Trevor; Zanation, Adam; Du, Eugenie
Abstract
Objectives Little data exist on associations between patient factors and postoperative analgesic requirement after head and neck (H&N) surgeries. Such information is important for optimizing postoperative care considering concerns regarding opioid misuse. We analyzed factors associated with narcotic use and pain perception following H&N surgery sparing the upper aerodigestive tract. Study Design Prospective cohort. Setting Tertiary referral center. Subjects and Methods From May to October 2017, data were collected for patients undergoing nonaerodigestive H&N procedures requiring hospitalization. Patients completed a preoperative survey querying chronic pain history, narcotic usage, and postoperative pain expectation. Demographics, surgical data, postoperative narcotic use defined by morphine milligram equivalents (MME), pain scores, and Overall Benefit of Analgesia Score (OBAS) were analyzed. Results Seventy-six patients, 44 (57.9%) females and 32 (42.1%) males with a mean age of 54.0 years, met inclusion criteria. The most common procedures were parotidectomy (27.6%) and total thyroidectomy (19.7%). Average cumulative 24-hour postoperative MME and calculated MME per hospital day (MME/HD, cumulative MME for hospitalization divided by length of stay) were 40.5 +/- 30.6 and 60.8 +/- 60.1, respectively. Average pain score throughout the initial 24 hours after surgery was 3.7/10 +/- 2.0. Female sex and prior chronic pain diagnosis were associated with higher OBAS after multivariate linear adjustments. Conclusion Postoperative narcotic requirement in nonaerodigestive H&N surgery is overall low. Female sex and prior chronic pain diagnosis may be associated with higher postoperative OBAS, a validated assessment of pain and opioid-related side effects. This study may serve as a comparison for future studies evaluating narcotic-sparing analgesia and pain perception in nonaerodigestive H&N surgery.