Dependence of large-scale precipitation climatologies on temporal and spatial sampling

Journal Article · Thu May 01 04:00:00 EDT 1997 · Journal of Climate

DOI:https://doi.org/10.1175/1520-0442(1997)010<1099:DOLSPC>2.0.CO;2· OSTI ID:501579

Hulme, M; New, M ^[1]

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1. Univ. of East Anglia, Norwich (United Kingdom)

Large-scale observed precipitation climatologies are needed for a variety of purposes in the fields of climate and environmental modeling. Although new satellite-derived precipitation estimates offer the prospect of near-global climatologies covering the last one or two decades, historical assessments of precipitation and its variability in time remain dependent on conventional gauge observations. A number of questions need to be asked of the existing precipitation climatologies that use such gauge observations. What time period do they sample? What is the spatial density of gauge coverage? What adjustments are made for measurement bias? And what interpolation method is used to convert them to regular grids? Different precipitation climatologies, nominally describing the same variable, can yield very different answers when used as inputs in either the fields of climate model validation or environmental modeling. This paper explores some of the reasons for these differences by examining the importance of the first two questions listed above-the temporal and spatial sampling of the precipitation normals that form the basis of these types of climatologies. The authors draw upon subcontinental examples from tropical North Africa and Europe and show that, in the presence of significant decadal-scale precipitation variability, climatologies constructed from the same station network, but sampling different 30-yr time periods, can vary by 25% or more. Using the same two regions, the authors also examine the influence of different spatiotemporal gauge sampling strategies on the construction of a long-term, {open_quotes}twentieth-century,{close_quotes} precipitation climatology. 39 refs., 14 figs., 1 tab.

• OSTI ID: 501579
• Journal Information: Journal of Climate, Journal Name: Journal of Climate Journal Issue: 5 Vol. 10; ISSN 0894-8755; ISSN JLCLEL
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ATMOSPHERIC PRECIPITATIONS
CLIMATE MODELS
CLIMATIC CHANGE
HISTORICAL ASPECTS
PERFORMANCE