How not to measure temperature, part 58 – Sacramento’s rooftop weather stations

While looking all over the USA at weather stations, I overlooked an interesting station very nearly in my own backyard. Sacramento. This official climate station, COOP ID #047633 is much like the one in Eureka, CA which also spent much of it’s life on the rooftop of the Post Office downtown. Among other places, the Sacramento station was recently (1999 or 2002 depending on how you interpret the record) moved to a ground level location which I will touch on later. While this is not a USHCN station, it is used by GISS.

The NWS WSFO in Sacramento has a climate summary (see it here) which includes the history of the many station moves, they write:

Through the years, the Sacramento Weather Office has changed locations several times. In succession, the office has been located at the following addresses:

1. 4th and J Streets (St. George Building), July 1, 1877 to November 27, 1879.

2. 2nd and K Streets (Fratts Building), November 28, 1879 to May 31, 1882.

3. 1006 2nd Street (Arcade Building), June 1, 1882 to January 31, 1884.

4. 117 J Street (Lyon and Curtis Building), February 1, 1884 to April 30, 1894

5. 7th and K Streets (Old Post Office Building), May 1, 1894 to October 31, 1933.

6. 9th and I Streets (New Post Office and Courthouse Building), November 1, 1933 to November 19, 1958.

7. 1725 23rd Street (State of California Building), November 20, 1958 to September 28, 1964.*

8. 1416 9th Street (Resources Building), September 29, 1964 to August 14, 1995.

9. 3310 El Camino Avenue, August 15, 1995 to present.

Note the asterisk on item 7. They have a separate paragraph to cover that:

On September 28, 1964, the observation site was returned to the post office building at 9th and I streets. On April 1, 1999, the sensors were moved to the Sacramento Water Treatment Plant, east of California State University-Sacramento. Temperature and precipitation data has been transmitted from these locations to the National Weather Service Office since September 28, 1964.

There’s an interesting story in all of this, and I’m going to tell you about it, complete with pictures. While I don’t have pictures of some of the older locations, the post office/courthouse at 9th and I Streets is still there:


Sacramento Post office as seen from 9th and “I” street

Here is the same angle but from an aerial view:


Sacramento, CA. 9th and “I” streets, click image for a live interactive view.

The NCDC MMS database indicates that indeed, the station was located on the rooftop of the U.S. Post Office in downtown Sacramento:

Unfortunately, I was unable to locate any historic photos of the exact placement, but the lat/lon listed places it near the NE corner of the building. Given what I’ve learned about rooftop placement of NWS weather stations in Baltimore, and in Eureka, the style has been to put the station on an elevated platform on the roof. partly due to protect the roof from the daily observer traffic. Also, given that the NWS tends to place stations for maximum convenience of the observer, you tend to find them near doors and stairwells. There appears to be a roof location on the post office roof that satisfies both the platform and convenience trends:


Click for a full sized image

Here is a better aerial angle, looking east from Live Maps. You can clearly see the stairwell for roof access and the elevated platform:


Click for a full sized image, or a live interactive view here

I’ve also created a magnified view, and it appears that the mast used to mount the wind vane and anemometer remains in place:

Like in Eureka and Baltimore WSFO Rooftop offices, the platform on the roof remained in place since to remove it would cost more money than leaving it in place and require roof maintenance. I think I’ve established where on the roof, the station had been located.

Now here is where it gets even more interesting, both the Eureka and Baltimore rooftop WSFO stations had been removed to ground level stations in the mid to late 1990’s (Eureka, 1994, Baltimore 1999) and Sacramento was no exception, they closed the downtown Post Office Station on August 14th, 1995 and moved it to 3310 El Camino Avenue, Sacramento, where the NWS was renting office space. But, it wasn’t a ground level location, it was another rooftop.

[1997-05-21]  1999-07-31  38.609170 (38°36’33″N)  -121.387220 (121°23’13″W)  GROUND: 54 FEET  —  SACRAMENTO  02 – SACRAMENTO DRAINAGE  PACIFIC (+8)  
Location Description: ON NWSO ROOFTOP WITHIN AND 7.0 MI NE OF MAIN PO AT SACRAMENTO, CO  Topographic Details: ON ROOF OF NWSO IN SUBURBAN SACRAMENTO. BROAD VALLEY SURROUNDING CITY. 

I doing an aerial search, I recognized one of the satellite dishes, since I have one myself.

They sure must like rooftops:


Click for a full sized image

if there is any question about the location, this view shows the building number clearly:


Click image for an interactive view of 3310 El Camino Avenue, Sacramento

Now here’s the funny thing, according to the station history in the climate summary writeup by the NWS Sacramento where they say:

3310 El Camino Avenue, August 15, 1995 to present.

The location at 3310 El Camino Avenue was only there for two years, and they also have that footnote in the climate summary that says:

On April 1, 1999, the sensors were moved to the Sacramento Water Treatment Plant, east of California State University-Sacramento.

According to NCDC’s MMS database while at 3310 El Camino Avenue it was assigned a COOP ID #047629, from 1997-05-21 to 1999-07-31 They call this station “Sacramento NWSO” while the “official” station at the downtown post office was “Sacramento WSO City”.

But when you look at the location data for the “Sacramento WSO City” station, there is no such written mention of the move, nor reference to lat/lon changes:

[2002-09-18] 9999-12-31 38.555560 (38°33’20″N) -121.416940 (121°25’00″W) GROUND: 38 FEET — SACRAMENTO 02 – SACRAMENTO DRAINAGE PACIFIC (+8)
Location Description: FAIRBAIRN WATER TREATMENT PLNT WITHIN AND 4.5 MILES ESE OF PO AT SACRAMENTO CA
Topographic Details: FLAT RIVER VALLEY SURROUNDING CITY
[2002-01-23] 2002-09-18 38.555560 (38°33’20″N) -121.416940 (121°25’00″W) GROUND: 38 FEET — SACRAMENTO 02 – SACRAMENTO DRAINAGE PACIFIC (+8)
Location Description: FAIRBAIRN WATER TREATMENT PLNT WITHIN AND 4.5 MILES ESE OF PO AT SACRAMENTO CA
Topographic Details: FLAT RIVER VALLEY SURROUNDING CITY
[1999-04-01] 2002-01-23 38.555560 (38°33’20″N) -121.416940 (121°25’00″W) GROUND: 38 FEET — SACRAMENTO 02 – SACRAMENTO DRAINAGE PACIFIC (+8)
Location Description: ON ROOF OF OLD PO AND COURTHOUSE BLDG 9TH AND I ST SACRAMENTO, CA
Topographic Details: ON ROOF OF PO BLDG DOWNTOWN SACRAMENTO, FLAT VALLEY SURROUNDING CITY
[1995-09-01] 1999-04-01 38.582500 (38°34’57″N) -121.494440 (121°29’39″W) GROUND: 25 FEET ESE/4.5/MILES SACRAMENTO 02 – SACRAMENTO DRAINAGE PACIFIC (+8)
Location Description: ON ROOF OF OLD PO AND COURTHOUSE BLDG 9TH AND I ST SACRAMENTO, CA
Topographic Details: TOPO-ON ROOF OF 18 STORY BUILDING IN METRO CENTER. FLAT SACRAMENTO VALLEY.
[1992-11-19] 1995-09-01 38.583330 (38°34’59″N) -121.500000 (121°30’00″W) GROUND: 25 FEET — SACRAMENTO 02 – SACRAMENTO DRAINAGE PACIFIC (+8)
Location Description: ON ROOF OF OLD PO AND COURTHOUSE BLDG, 9TH & I ST, SACRAMENTO, CA.
Topographic Details: TOPO- ON ROOF 18 STORY BLDG IN METRO CENTER; FLAT SAC VALLEY.
[1988-06-06] 1992-11-19 38.583330 (38°34’59″N) -121.500000 (121°30’00″W) GROUND: 25 FEET — SACRAMENTO 02 – SACRAMENTO DRAINAGE PACIFIC (+8)

It is almost as if the location at 3310 El Camino was an “experiment” gone wrong, and the records were never updated. Perhaps the station at the post office was operated in parallel during the time. The climate summary says the station was moved to the sewage treatment plant in 1999, but the NCDC MMS database location record says 2002.

Which one is correct? It is quite odd.

If you believe NCDC, the station was finally moved for good in 2002, to a sewage treatment plant on the south side of town, at ground level. Though given what we’ve learned about sewage treatment plants, I’m not sure this would be any better, and possibly a worse location than either the post office roof or the El Camino Avenue roof.

The equipment list showed that at the new location, a mercury max-min was used as backup plus the primary was listed as “RADIO TRANSMITTED”:


Click for a full sized image

So looking for a Stevenson Screen and an antenna/equipment tower at the lat/lon provided, it was a fairly simple matter to find the location of the new station at the sewage treatment plant:


Click image for a live interactive view

So you be the judge, which is the better location? Rooftops or sewage treatment plants? Tough question.

Perhaps untangling the temperature record for this station will provide some clues, though with so many moves, and with uncertain documentation about those moves from NCDC, the task might be a daunting one. In any case, it seems that stations with such a varied history and uncertain documentation aren’t likely to be good candidates for capturing long term climate trends.

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16 thoughts on “How not to measure temperature, part 58 – Sacramento’s rooftop weather stations

  1. IceCap today has a very interesting post by David J. Ameling concerning global cooling, earth rotational speed and ice cap growth.
    GISS instruments and data may show a warming trend, but everything else points to the opposite. It’s only a question of time before GISS will be forced to admit its sources of data and overall calculation are absurdedly remote of reality.

  2. Agreed Pierre. The Icecap post is very interesting. It’s easy to think in this morass of surface temp records that we will never get any good data about anything. The Icecap post is a precise measure with only one explanation – the polar icecaps are gaining substantial mass.

    Although, I’ll note that while the warmers make much of the supposedly shrinking icecaps due to AGW, you would in fact expect the opposite – because most of their area is below zero most or all of the time and we would have more precipitation in a warmer world.

  3. It’s not just GISS that’s the problem.

    http://climatesci.org/2008/04/14/blatant-bias-in-two-new-papers-in-assessing-trends-in-surface-temperature-extremes/

    http://www.metoffice.gov.uk/corporate/pressoffice/2008/pr20080326.html

    One might ask why GISS and Met O ignore all studies cataloging these issues. I don’t think it’s a mystery at all. Satellite data does not show these temperature extremes, and there’s a reason why.

    How can this recent long term study be dismissed?
    http://www.geography.uc.edu/~kenhinke/uhi/Hinkel&Nelson_JGR-A_2007.pdf

  4. Even though this is grossly misplaced, in the overall scheme of things haven’t they all been consistently misplaced? And if so, can all past temps be pretty much “normalized” against a new unit placed properly?

    Jack Koenig, Editor
    The Mysterious Climate Project
    http://www.climateclinic.com

  5. This may be a wee bit OT, but is the data from these surface stations used for historical data only, or is it used by the NWS and others for real time data also? The reason I ask is this morning the current temp (within 10 min) from three sources were 35, 36, 39 for my local area (rural county). My handy-dandy weather station gave the temp as 31 (verified by a fair to middlin frost on the ground) Even with microclimates that appears to be a rather wide range between sources.

    REPLY: It depends on the station categorization. This one is used by GISS for climate study. Some stations are only used for hydrologic or forecasting work.

  6. These are great posts. Can someone point me in the right direction on the correct way to measure and report temperature?

  7. Should I be looking at the ice cap size (thickness), and not sea ice area?

    Area is more important because of its effect on albedo.

  8. Even though this is grossly misplaced, in the overall scheme of things haven’t they all been consistently misplaced? And if so, can all past temps be pretty much “normalized” against a new unit placed properly?

    If it were waste heat, yes. But with a heat sink, first there is an offset and after that, the trend is–continually–exaggerated in either direction (limited by the size/density, etc., of the sink). Notice that temps are up over a full degree before the final move (considerably more than world or national average).

    It’s not as simple as merely changing an anomaly baseline.

  9. Evan,
    Yes albedo is important in the heat transfer equation. But I’d say the polar sea ice area plays no role on the earth’s rotational speed. That’s why I’m having a hard time accepting David Ameling’s post at IceCap.

  10. Sea ice shouldn’t have any effect on the Earth’s rotation. It’s just sea water frozen moreorless in place.

    We know the largest icesheet on the planet the East Antarctica icesheet is growing. That’s probably where most of the increased polar mass is.

    The East Antarctica Icesheet is 2 to 4 thousand meters thick. That’s an awful lot of mass.

  11. Moving mass closer to the spin axis of the earth will increase its rate. Precipitation that increases the Polar caps will do this.

    Heating of the oceans would increase the volume and move more mass away from the axis slowing the spin. Argo says no ocean warming for several years.

    Melting of mountain glaciers will move mass closer to the spin axis. Melting of Polar Glaciers might have a net opposite effect. Is there detailed data on glacier height and size?

    We are told that the sea level is increasing yearly. This should slow the spin depending on where the water is coming from. Of course, Dr. Moerner thinks they are scamming us on the Sea Level.

    Here is a short article on icecaps and spin:

    http://icecap.us/images/uploads/The_Ice_Caps_are_Growing.pdf

    In his second reason I would add that the eddy currents would also HEAT the earth, whereas a lessening of the field would reduce the currents and the incidental heating. This may not be noticeable at the surface over a short term.

  12. Pingback: How not to measure temperature, part 81 - roofing the past in Columbia « Watts Up With That?

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