From the Saudi Gazette
In one of the rare occasions, Saudis enjoy the snowfall in Al-Baha city south-west of Riyadh, Tuesday. Torrential rains pouring down on Al-Baha accompanied by gusty winds were accompanied by snow capping the mountains and covering the valley areas and the forests of Al-Zaraeb and Khayrah.
The fact that my work is mentioned by NCDC at all is a small miracle, even if it is “muted”, as Roger says. However, I’m pleased to get a mention and I express my thanks to Matt Menne for doing so. Unfortunately they ducked the issue of the long term site bias contribution and UHI to the surface record. But, we’ll address that later – Anthony
Yes, find the temperature shelters, I did.
From Roger Pielke Sr.’s Climate Science website
There is a new paper on the latest version of the United States Historical Climatololgy Network (USHCN). This data is used to monitor and report on surface air temperature trends in the United States. The paper is
Matthew J. Menne, Claude N. Williams, Jr. and Russell S. Vose, 2009: The United States Historical Climatology Network Monthly Temperature Data – Version 2.(PDF) Bulletin of the American Meteorological Society (in press). [url for a copy of the paper added thanks and h/t to Steve McIntyre and RomanM on Climate Audit].
The abstract reads
“In support of climate monitoring and assessments, NOAA’s National Climatic Data Center has developed an improved version of the U.S. Historical Climatology Network temperature dataset (U.S. HCN version 2). In this paper, the U.S. HCN version 2 temperature data are described in detail, with a focus on the quality-assured data sources and the systematic bias adjustments. The bias adjustments are discussed in the context of their impact on U.S. temperature trends from 1895-2007 and in terms of the differences between version 2 and its widely used predecessor (now referred to as U.S. HCN version 1). Evidence suggests that the collective impact of changes in observation practice at U.S. HCN stations is systematic and of the same order of magnitude as the background climate signal. For this reason, bias adjustments are essential to reducing the uncertainty in U.S. climate trends. The largest biases in the HCN are shown to be associated with changes to the time of observation and with the widespread changeover from liquid-in-glass thermometers to the maximum minimum temperature sensor (MMTS). With respect to version 1, version 2 trends in maximum temperatures are similar while minimum temperature trends are somewhat smaller because of an apparent over correction in version 1 for the MMTS instrument change, and because of the systematic impact of undocumented station changes, which were not addressed version 1.”
I was invited to review this paper, and to the authors credit, they did make some adjustments to their paper in their revision. Unfortunately, however, they did not adequately discuss a number of remaining bias and uncertainty issues with the U.S. HCN version 2 data. Read the rest of this entry »
WUWT reader David Summers sends this photo along taken a few days ago in 2007 in Australia from a colleague that “returned there for the summer”. I thought it might make a fun photo caption exercise.
This interesting essay by Dr. Spencer is reposted from his blog, link here:
Global Warming Causing Carbon Dioxide Increases: A Simple Model
May 11th, 2009 by Roy W. Spencer, Ph. D.
Global warming theory assumes that the increasing carbon dioxide concentration in the atmosphere comes entirely from anthropogenic sources, and it is that CO2 increase which is causing global warming.
But it is indisputable that the amount of extra CO2 showing up at the monitoring station at Mauna Loa, Hawaii each year (first graph below) is strongly affected by sea surface temperature (SST) variations (second graph below), which are in turn mostly a function of El Nino and La Nina conditions (third graph below):
Click for larger images
Read the rest of this entry »
PDO — ENSO, Aleutian Low, or some of each?
Guest Post by Basil Copeland
Introduction
In a recent post here at WUWT, as well as on his own blog, Bob Tisdale challenged the popular view that the Pacific Decadal Oscillation (PDO) is a principal driver of climate independent of the tropical El Nino-Southern Oscillation (ENSO) system. Presenting the results of his own analysis, as well as citations from published scientific literature, Bob at least made the case for some plausible relationship between PDO and ENSO. But what is the nature of this relationship, and does it reduce PDO to, as Bob put it, merely “a pattern of SST variability, not SST” itself?
Bob quoted extensively from Newman et al. (2003). While this paper was in press at the time, it was reviewed and considered by Miller et al. (2004). The latter is a comprehensive review of “Decadal-Scale Climate and Ecosystem Interactions in the North Pacific Ocean” (e.g., the title of the paper). While acknowledging a tropical forcing (ENSO) on North Pacific SSTs, they contend that there is another, distinct forcing that is independent of the tropical forcing, related on decadal time scales to the behavior of the Aleutian Low.
In this post I will be citing selected portions of the Miller et al. paper, and presenting some simple empirical data that demonstrate the complex reality of the PDO. While on an interannual to decadal scale it is possible to demonstrate a “teleconnection” between ENSO and the PDO, on multi-decadal time scales this teleconnection appears to have little power to explain the behavior of the PDO. Instead, the multi-decadal pattern of the PDO is based — or “forced” — on midlatitude climate variability reflected in the behavior of the Aleutian Low. Specifically, I will bring into the discussion the North Pacific Index (NPI). The NPI is calculated as the area-weighted sea level pressure over the region 30°N-65°N, 160°E-140°W, and provides a measure of the intensity of the wintertime Aleutian Low. I’ve taken the monthly NPI data, created a moving average, and have normalized and inverted it so that it scales similarly to ENSO and the PDO for purposes of comparison. For ENSO, I am using a series for Nino 3.4. All data sources are cited in a reference list at the end of this post.
Power Spectrum: Nino 3.1, PDO, and NPI
Or if you like, fling funds
to help keep the www.surfacestations.org project going.
Sea Ice
DMI Polar Temperature
Sunspots
Mars Today:
RSS - Posts
Recent Comments