Graduate Thesis Or Dissertation
 

The energy budget of a pumice desert

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/p2676x949

Descriptions

Attribute NameValues
Creator
Abstract
  • The energy budget of a pumice desert surface was analyzed under clear skies during early, mid- and late summer periods. The pumice site is in the semi-arid plateau region of Central Oregon at an elevation of about 1500 meters. The flat pumice surface is approximately 250 hectares in extent, and is bordered by a sparse lodgepole pine forest. Energy budget components of net radiation, soil heat flux, sensible heat flux, and latent heat flux were evaluated for one clear day in each of the three measurement periods. The daily energy budget totals were (cal/cm2 day): The most significant features of the pumice desert energy budget were: 1) Radiant energy transformed by the pumice surface (net 17 July 1969 13 August 1969 4 September 1969 228 194 Net radiatiOn 258 Soil heat flux -7 -14 -2 Sensible heat flux -197 -197 -180 Latent heat flux -54 -17 -11 radiation) was approximately 60 percent of the amount measured over a nearby forested surface; 2) Energy transfer into the soil amounted to less than 3 percent of the energy supplied to the surface by net radiation, while surface temperatures varied through a 50°C range each day; 3) Sensible heat flux dissipated 85 percent of the net radiation supplied to the surface; and, 4) Evaporation at the pumice site averaged less than 0. 05 cm per day, although the pumice beneath the dry surface layer remained moist. A unique stability correction, φ , for the aerodynamic flux analysis of sensible or latent heat was developed to extend over the wide stability range found at the pumice site. The form of this correction during unstable conditions is: φ= (1-34Ri).55 where Ri is Richardson's stability parameter. A method for estimating the uncertainty of the measurement system and of the resultant flux analyses was developed and applied to the results of this study. The average relative uncertainties of the net radiation and soil heat flux analyses were estimated to be less than 1 percent and 5 percent, respectively. The average uncertainty of the sensible heat flux analyses was estimated to be 3 percent when using an aerodynamic model, and 9 percent when using the Bowen ratio model. The corresponding figures for latent heat flux are 25 percent with the aerodynamic model and 30 percent with the Bowen ratio model. The larger percentage uncertainties associated with latent heat are due in part to the small vapor pressure gradients near the pumice surface, relative to the measurement capabilities, and in part to the small values of the latent heat flux. This study demonstrates the applicability of micrometeorological theory in characterizing complex microclimatological relationships by presenting them in a concise, comparable form through use of the energy budget.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • Master files scanned at 600 ppi (256 Grayscale) using Capture Perfect 3.0 on a Canon DR-9080C in TIF format. PDF derivative scanned at 300 ppi (256 B+W), using Capture Perfect 3.0, on a Canon DR-9080C. CVista PdfCompressor 3.1 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details Holbo__Harold_R_1972_PhD.pdf 2017-08-08 Public Download