Student Seminar Series - July 21, 2005
University of Minnesota
School of Statistics
College of Liberal Arts
Exploratory
Statistical Time Trend Study of GISS Global Seawater Oxygen-18
Database
Jie Xu
Thursday, July 21, 2005
2:00 PM, 115
Ford Hall
Minneapolis, East Bank Campus
Refreshments at 1:30 PM
300 Ford Hall
Abstract
NASA Goddard Institute for Space Studies (GISS) have global
seawater
Oxygen-18 database which have good format and are free to download. The
reference researches on this data are mainly conducted by geologists
and
physicists on the water flowing, current and climate for different
ocean
locations. In this project we will study the time trend of ocean
temperature, salinity and oxygen 18 globally. Locally regression model
(loess) was applied to the data. The mean, standard deviation, median,
p5
and p95 of residual from loess fitting were estimated for each time
point.
Linear regressions of these five statistics on time were built. The
result
showed p5 for ocean temperature has slightly decreasing trend over
time;
the p95 of salinity also has slightly decreasing trend; mean, median
and p5
of oxygen 18 have slightly increasing trend.