Lecture Outline

Script

Reading

Home Work

Mid Term Example

Final Exam Example

Models

1-D EBM

Field Class

First day
NEW Data File

Second day
NEW Data File

GEOG 5211/4211 - Fall 2003

Professor Konrad Steffen
CIRES Ekeley Building, S264
Tel o: 492 4524
e-mail konrad.steffen@colorado.edu

Field Excursion: November 8 & 22, 2003

1. Relative Calibration of Wind, Temperature and Humidity Sensors

Relative accuracy is required to derive profiles of temperature, wind and humidity for flux calculation using the aerodynamic method.  All instruments are mounted at the same level to monitor the environmental data.  The following procedure is proposed to calibrate the instruments (i.e., wind anemometer) relative to each other:

a)    Select one instrument as the reference (e.g. mean wind speed, sensor 1)
b)    Derive the mean difference between wind sensor 1,2, and 3 for the entire measuring period.
c)    Derive the mean wind difference between the wind sensors for certain wind speed levels (e.g. 0-2 m/s, 2-4 m/s, …). Compare the results from a) and b).
d)    Propose a correction function for wind sensors 2,3,based on your analysis above.

The same procedure is applied for temperature and humidity measurements. Analyze the data set and derived the offset of the sensors versus a standard (standard instrument: just select on the three identical sensors of temperature, relative humidity, and wind speed).

Sensors:     Temperature/Humidity: Vaisala HMP45C (http://www.campbellsci.com/temp_rh.html)
Wind: RM Young 05103 (http://www.campbellsci.com/wind.html)

2. Radiation measurements

In this experiment we measure the radiation balance using a net radiometer, shortwave incoming and reflected solar radiation, and surface temperature. Given these measurements, you can calculate the long-wave outgoing radiation. Make point measurements (use the average of three readings) over different surface types (i.e., grass, concrete, turf, brush, and others - shaded and un-shaded) for shaded and un-shaded conditions (if sun is available).  

Li-Core pyranometer (incoming radiation), Serial No. PY44078, Output 0.2 kW m-2 mV-1
Li-Core pyranometer (incoming radiation), Serial No: PY44039, Output 0.2 kW m-2 mV-1
Kipp & Zonen  Net Radiometer Serial No. 021049; Sensitivity: 13.9 V / W m2
Everest Infrared Thermometer, Model 110C, Serial No: 1780, Output 100 mV for 10.0 deg. C

Campbell home page for Radiation: http://www.campbellsci.com/solarrad.html
Everest Homepage: http://www.everestinterscience.com/products/model100/100.3ZL.htm

Provide a summary of the following radioactive fluxes for a number of different surface types:
1.    Albedo (solar radiation)
2.    Long-wave out radiation
3.    Long-wave sky radiation
 
Reading assignment:
•    Calibration of temperature, humidity and wind sensors
•    Chapter 5: Air Temperature and Humidity in the PBL (49-64)
•    Chapter 6: Wind Distribution in the PBL (67-84)

The relative calibration data from the field class can be downloaded : ftp://seaice.colorado.edu/pub/class