Finding the Time Lag Between Solar Heating and Surface

TemperatureEAS 4480: Data Analysis Final Project

Arielle Nixon24 April 2012

Introduction

Determine:

•correlation between incoming solar radiation at the Atlanta Hartsfield-Jackson Airport (KATL) and change in air temperature/SST

•Lag time between each of these correlated data sets

Gather data: Daily mean air temperature Incoming solar insulation Sea surface temperature

Compute Autocorrelations of each data set Compute correlation coefficients to determine

which components are most closely related Cross correlate IR with Air Temp and SST to find

lag time

Methods

Climatological Daily Mean Temperatures from KATL for 2011

Smoothed Climatological Daily Mean Temperatures from KATL for 2011

Residual Climatological Daily Mean Temperatures from KATL for 2011

Daily Mean and Smoothed Temperature from KATL for 2011

Autocorrelation: Climatological Daily Mean Temperature

Autocorrelation: Smoothed Daily Mean Temperature

Autocorrelation: Residual of Daily Mean Temperature

Autocorrelation: Daily Mean Incoming Solar Insulation

Autocorrelation: Daily Mean Sea Surface Temperature

Autocorrelation as a Function of Time Lag

Correlation Coefficients

Correlation Coefficients (r)Climate Smooth Residual IR SST

Climate 1 0.9976 0.2356 0.8867 0.8008Smooth 0.9976 1 0.1671 0.8887 0.8027Residual 0.2356 0.1671 1 0.1508 0.1346IR 0.8867 0.8887 0.1508 1 0.4427SST 0.8008 0.8027 0.1346 0.4427 1

How Much of the variance in X is explained by Y? (r2)Climate Smooth Residual IR SST

Climate 1 0.995206 0.055507 0.786237 0.641281Smooth 0.995206 1 0.027922 0.789788 0.644327Residual 0.055507 0.027922 1 0.022741 0.018117IR 0.786237 0.789788 0.022741 1 0.195983SST 0.641281 0.644327 0.018117 0.195983 1

Cross-Correlation between Smoothed Daily Temperature & Daily Incoming

Solar InsulationMax correlation of 0.92814 at Lag= 17

Cross-Correlation between Sea Surface Temperature & Daily Incoming

Solar Insulation

Max correlation of 0.85211 at Lag= 58

At a time lag of 17 days, the increase/decrease in solar insulation has the most causal effect on the mean air temperature at KATL

At a time lag of 58 days, the increase/decrease in solar insulation have the most causal effect on the sea surface temperature

Results

Daily Mean Air Temperature data http://

www.esrl.noaa.gov/psd/cgi-bin/data/getpage.pl Incoming Solar Insulation data

http://aom.giss.nasa.gov/srlocat.html Sea Surface Temperature Data

http://www.esrl.noaa.gov/psd/data/gridded/data.noaa.oisst.v2.highres.html

Resources